[libcamera-devel,v6,7/9] android: camera_device: Use the new CameraMetadata helper class

Message ID 20190905074737.6955-8-jacopo@jmondi.org
State Superseded
Headers show
Series
  • android: Rework metadata tags
Related show

Commit Message

Jacopo Mondi Sept. 5, 2019, 7:47 a.m. UTC
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Simplify the implementation of metadata handling in the CameraDevice
class by using the new CameraMetadata helper class.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 src/android/camera_device.cpp | 507 +++++++++++++---------------------
 src/android/camera_device.h   |  15 +-
 2 files changed, 198 insertions(+), 324 deletions(-)

Comments

Jacopo Mondi Sept. 5, 2019, 8:18 a.m. UTC | #1
Hi Laurent,

On Thu, Sep 05, 2019 at 09:47:34AM +0200, Jacopo Mondi wrote:
> From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>
> Simplify the implementation of metadata handling in the CameraDevice
> class by using the new CameraMetadata helper class.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>  src/android/camera_device.cpp | 507 +++++++++++++---------------------
>  src/android/camera_device.h   |  15 +-
>  2 files changed, 198 insertions(+), 324 deletions(-)
>
> diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
> index 5f8d19b9ef3d..475fa2404421 100644
> --- a/src/android/camera_device.cpp
> +++ b/src/android/camera_device.cpp
> @@ -7,10 +7,10 @@
>
>  #include "camera_device.h"
>
> -#include <system/camera_metadata.h>
> -
>  #include "log.h"
> +#include "utils.h"
>
> +#include "camera_metadata.h"
>  #include "thread_rpc.h"
>
>  using namespace libcamera;
> @@ -59,12 +59,10 @@ CameraDevice::CameraDevice(unsigned int id, const std::shared_ptr<Camera> &camer
>  CameraDevice::~CameraDevice()
>  {
>  	if (staticMetadata_)
> -		free_camera_metadata(staticMetadata_);
> -	staticMetadata_ = nullptr;
> +		delete staticMetadata_;
>
>  	if (requestTemplate_)
> -		free_camera_metadata(requestTemplate_);
> -	requestTemplate_ = nullptr;
> +		delete requestTemplate_;
>  }
>
>  /*
> @@ -117,10 +115,8 @@ void CameraDevice::setCallbacks(const camera3_callback_ops_t *callbacks)
>   */
>  camera_metadata_t *CameraDevice::getStaticMetadata()
>  {
> -	int ret;
> -
>  	if (staticMetadata_)
> -		return staticMetadata_;
> +		return staticMetadata_->get();
>
>  	/*
>  	 * The here reported metadata are enough to implement a basic capture
> @@ -132,16 +128,21 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
>  	 * \todo Keep this in sync with the actual number of entries.
>  	 * Currently: 46 entries, 390 bytes
>  	 */
> -	staticMetadata_ = allocate_camera_metadata(50, 500);
> +	staticMetadata_ = new CameraMetadata(50, 500);
> +	if (!staticMetadata_->isValid()) {
> +		LOG(HAL, Error) << "Failed to allocate static metadata";
> +		delete staticMetadata_;
> +		staticMetadata_ = nullptr;
> +		return nullptr;

Empty line before return?

> +	}
>
>  	/* Color correction static metadata. */
>  	std::vector<uint8_t> aberrationModes = {
>  		ANDROID_COLOR_CORRECTION_ABERRATION_MODE_OFF,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES,
> -			aberrationModes.data(), aberrationModes.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES,
> +				  aberrationModes.data(),
> +				  aberrationModes.size());
>
>  	/* Control static metadata. */
>  	std::vector<uint8_t> aeAvailableAntiBandingModes = {
> @@ -150,294 +151,228 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
>  		ANDROID_CONTROL_AE_ANTIBANDING_MODE_60HZ,
>  		ANDROID_CONTROL_AE_ANTIBANDING_MODE_AUTO,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES,
> -			aeAvailableAntiBandingModes.data(),
> -			aeAvailableAntiBandingModes.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES,
> +				  aeAvailableAntiBandingModes.data(),
> +				  aeAvailableAntiBandingModes.size());
>
>  	std::vector<uint8_t> aeAvailableModes = {
>  		ANDROID_CONTROL_AE_MODE_ON,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_CONTROL_AE_AVAILABLE_MODES,
> -			aeAvailableModes.data(), aeAvailableModes.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_MODES,
> +				  aeAvailableModes.data(),
> +				  aeAvailableModes.size());
>
>  	std::vector<int32_t> availableAeFpsTarget = {
>  		15, 30,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES,
> -			availableAeFpsTarget.data(),
> -			availableAeFpsTarget.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES,
> +				  availableAeFpsTarget.data(),
> +				  availableAeFpsTarget.size());
>
>  	std::vector<int32_t> aeCompensationRange = {
>  		0, 0,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_CONTROL_AE_COMPENSATION_RANGE,
> -			aeCompensationRange.data(),
> -			aeCompensationRange.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_COMPENSATION_RANGE,
> +				  aeCompensationRange.data(),
> +				  aeCompensationRange.size());
>
>  	const camera_metadata_rational_t aeCompensationStep[] = {
>  		{ 0, 1 }
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_CONTROL_AE_COMPENSATION_STEP,
> -			aeCompensationStep, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_COMPENSATION_STEP,
> +				  aeCompensationStep, 1);
>
>  	std::vector<uint8_t> availableAfModes = {
>  		ANDROID_CONTROL_AF_MODE_OFF,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_CONTROL_AF_AVAILABLE_MODES,
> -			availableAfModes.data(), availableAfModes.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_CONTROL_AF_AVAILABLE_MODES,
> +				  availableAfModes.data(),
> +				  availableAfModes.size());
>
>  	std::vector<uint8_t> availableEffects = {
>  		ANDROID_CONTROL_EFFECT_MODE_OFF,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_CONTROL_AVAILABLE_EFFECTS,
> -			availableEffects.data(), availableEffects.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_EFFECTS,
> +				  availableEffects.data(),
> +				  availableEffects.size());
>
>  	std::vector<uint8_t> availableSceneModes = {
>  		ANDROID_CONTROL_SCENE_MODE_DISABLED,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_CONTROL_AVAILABLE_SCENE_MODES,
> -			availableSceneModes.data(), availableSceneModes.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_SCENE_MODES,
> +				  availableSceneModes.data(),
> +				  availableSceneModes.size());
>
>  	std::vector<uint8_t> availableStabilizationModes = {
>  		ANDROID_CONTROL_VIDEO_STABILIZATION_MODE_OFF,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES,
> -			availableStabilizationModes.data(),
> -			availableStabilizationModes.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES,
> +				  availableStabilizationModes.data(),
> +				  availableStabilizationModes.size());
>
>  	std::vector<uint8_t> availableAwbModes = {
>  		ANDROID_CONTROL_AWB_MODE_OFF,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_CONTROL_AWB_AVAILABLE_MODES,
> -			availableAwbModes.data(), availableAwbModes.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_CONTROL_AWB_AVAILABLE_MODES,
> +				  availableAwbModes.data(),
> +				  availableAwbModes.size());
>
>  	std::vector<int32_t> availableMaxRegions = {
>  		0, 0, 0,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_CONTROL_MAX_REGIONS,
> -			availableMaxRegions.data(), availableMaxRegions.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_CONTROL_MAX_REGIONS,
> +				  availableMaxRegions.data(),
> +				  availableMaxRegions.size());
>
>  	std::vector<uint8_t> sceneModesOverride = {
>  		ANDROID_CONTROL_AE_MODE_ON,
>  		ANDROID_CONTROL_AWB_MODE_AUTO,
>  		ANDROID_CONTROL_AF_MODE_AUTO,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_CONTROL_SCENE_MODE_OVERRIDES,
> -			sceneModesOverride.data(), sceneModesOverride.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_CONTROL_SCENE_MODE_OVERRIDES,
> +				  sceneModesOverride.data(),
> +				  sceneModesOverride.size());
>
>  	uint8_t aeLockAvailable = ANDROID_CONTROL_AE_LOCK_AVAILABLE_FALSE;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_CONTROL_AE_LOCK_AVAILABLE,
> -			&aeLockAvailable, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_LOCK_AVAILABLE,
> +				  &aeLockAvailable, 1);
>
>  	uint8_t awbLockAvailable = ANDROID_CONTROL_AWB_LOCK_AVAILABLE_FALSE;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
> -			&awbLockAvailable, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
> +				  &awbLockAvailable, 1);
>
>  	char availableControlModes = ANDROID_CONTROL_MODE_AUTO;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_CONTROL_AVAILABLE_MODES,
> -			&availableControlModes, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_MODES,
> +				  &availableControlModes, 1);
>
>  	/* JPEG static metadata. */
>  	std::vector<int32_t> availableThumbnailSizes = {
>  		0, 0,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
> -			availableThumbnailSizes.data(),
> -			availableThumbnailSizes.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
> +				  availableThumbnailSizes.data(),
> +				  availableThumbnailSizes.size());
>
>  	/* Sensor static metadata. */
>  	int32_t pixelArraySize[] = {
>  		2592, 1944,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -				ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
> -				&pixelArraySize, 2);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
> +				  &pixelArraySize, 2);
>
>  	int32_t sensorSizes[] = {
>  		0, 0, 2560, 1920,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -				ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
> -				&sensorSizes, 4);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
> +				  &sensorSizes, 4);
>
>  	int32_t sensitivityRange[] = {
>  		32, 2400,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -				ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
> -				&sensitivityRange, 2);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
> +				  &sensitivityRange, 2);
>
>  	uint16_t filterArr = ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT_GRBG;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -				ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
> -				&filterArr, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
> +				  &filterArr, 1);
>
>  	int64_t exposureTimeRange[] = {
>  		100000, 200000000,
>  	};

I've been thinking for a while to stabilize on the use of std::vector in
place of arrays, so e can always use .data() and .size() and have
guaranteed we should only change the declaration and not the
parameters to the addEntry() operation.

This might be a good time to do so. What do you think?

> -	ret = add_camera_metadata_entry(staticMetadata_,
> -				ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> -				&exposureTimeRange, 2);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> +				  &exposureTimeRange, 2);
>
>  	int32_t orientation = 0;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -				ANDROID_SENSOR_ORIENTATION,
> -				&orientation, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_SENSOR_ORIENTATION,
> +				  &orientation, 1);

Fits in 1 line

>
>  	std::vector<int32_t> testPatterModes = {
>  		ANDROID_SENSOR_TEST_PATTERN_MODE_OFF,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -				ANDROID_SENSOR_AVAILABLE_TEST_PATTERN_MODES,
> -				testPatterModes.data(), testPatterModes.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_SENSOR_AVAILABLE_TEST_PATTERN_MODES,
> +				  testPatterModes.data(),
> +				  testPatterModes.size());
>
>  	std::vector<float> physicalSize = {
>  		2592, 1944,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -				ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
> -				physicalSize.data(), physicalSize.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
> +				  physicalSize.data(),
> +				  physicalSize.size());

Fits in 1 line

>
>  	uint8_t timestampSource = ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE_UNKNOWN;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE,
> -			&timestampSource, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE,
> +				  &timestampSource, 1);
>
>  	/* Statistics static metadata. */
>  	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
> -			&faceDetectMode, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
> +				  &faceDetectMode, 1);
>
>  	int32_t maxFaceCount = 0;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
> -			&maxFaceCount, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
> +				  &maxFaceCount, 1);
>
>  	/* Sync static metadata. */
>  	int32_t maxLatency = ANDROID_SYNC_MAX_LATENCY_UNKNOWN;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_SYNC_MAX_LATENCY, &maxLatency, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_SYNC_MAX_LATENCY, &maxLatency, 1);
>
>  	/* Flash static metadata. */
>  	char flashAvailable = ANDROID_FLASH_INFO_AVAILABLE_FALSE;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_FLASH_INFO_AVAILABLE,
> -			&flashAvailable, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_FLASH_INFO_AVAILABLE,
> +				  &flashAvailable, 1);
>
>  	/* Lens static metadata. */
>  	std::vector<float> lensApertures = {
>  		2.53 / 100,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -				ANDROID_LENS_INFO_AVAILABLE_APERTURES,
> -				lensApertures.data(), lensApertures.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_APERTURES,
> +				  lensApertures.data(),
> +				  lensApertures.size());
>
>  	uint8_t lensFacing = ANDROID_LENS_FACING_FRONT;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -				ANDROID_LENS_FACING, &lensFacing, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_LENS_FACING, &lensFacing, 1);
>
>  	std::vector<float> lensFocalLenghts = {
>  		1,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -				ANDROID_LENS_INFO_AVAILABLE_FOCAL_LENGTHS,
> -				lensFocalLenghts.data(),
> -				lensFocalLenghts.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_FOCAL_LENGTHS,
> +				  lensFocalLenghts.data(),
> +				  lensFocalLenghts.size());
>
>  	std::vector<uint8_t> opticalStabilizations = {
>  		ANDROID_LENS_OPTICAL_STABILIZATION_MODE_OFF,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -				ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
> -				opticalStabilizations.data(),
> -				opticalStabilizations.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
> +				  opticalStabilizations.data(),
> +				  opticalStabilizations.size());
>
>  	float hypeFocalDistance = 0;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -				ANDROID_LENS_INFO_HYPERFOCAL_DISTANCE,
> -				&hypeFocalDistance, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_HYPERFOCAL_DISTANCE,
> +				  &hypeFocalDistance, 1);
>
>  	float minFocusDistance = 0;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -				ANDROID_LENS_INFO_MINIMUM_FOCUS_DISTANCE,
> -				&minFocusDistance, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_MINIMUM_FOCUS_DISTANCE,
> +				  &minFocusDistance, 1);
>
>  	/* Noise reduction modes. */
>  	uint8_t noiseReductionModes = ANDROID_NOISE_REDUCTION_MODE_OFF;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -				ANDROID_NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES,
> -				&noiseReductionModes, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES,
> +				  &noiseReductionModes, 1);
>
>  	/* Scaler static metadata. */
>  	float maxDigitalZoom = 1;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_SCALER_AVAILABLE_MAX_DIGITAL_ZOOM,
> -			&maxDigitalZoom, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_MAX_DIGITAL_ZOOM,
> +				  &maxDigitalZoom, 1);
>
>  	std::vector<uint32_t> availableStreamFormats = {
>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB,
>  		ANDROID_SCALER_AVAILABLE_FORMATS_YCbCr_420_888,
>  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_SCALER_AVAILABLE_FORMATS,
> -			availableStreamFormats.data(),
> -			availableStreamFormats.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_FORMATS,
> +				  availableStreamFormats.data(),
> +				  availableStreamFormats.size());
>
>  	std::vector<uint32_t> availableStreamConfigurations = {
>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920,
> @@ -447,65 +382,57 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
>  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED, 2560, 1920,
>  		ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS_OUTPUT,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS,
> -			availableStreamConfigurations.data(),
> -			availableStreamConfigurations.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS,
> +				  availableStreamConfigurations.data(),
> +				  availableStreamConfigurations.size());
>
>  	std::vector<int64_t> availableStallDurations = {
>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920, 33333333,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_SCALER_AVAILABLE_STALL_DURATIONS,
> -			availableStallDurations.data(),
> -			availableStallDurations.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_STALL_DURATIONS,
> +				  availableStallDurations.data(),
> +				  availableStallDurations.size());
>
>  	std::vector<int64_t> minFrameDurations = {
>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920, 33333333,
>  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED, 2560, 1920, 33333333,
>  		ANDROID_SCALER_AVAILABLE_FORMATS_YCbCr_420_888, 2560, 1920, 33333333,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_SCALER_AVAILABLE_MIN_FRAME_DURATIONS,
> -			minFrameDurations.data(), minFrameDurations.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_MIN_FRAME_DURATIONS,
> +				  minFrameDurations.data(),
> +				  minFrameDurations.size());
>
>  	uint8_t croppingType = ANDROID_SCALER_CROPPING_TYPE_CENTER_ONLY;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_SCALER_CROPPING_TYPE, &croppingType, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_SCALER_CROPPING_TYPE, &croppingType, 1);
>
>  	/* Info static metadata. */
>  	uint8_t supportedHWLevel = ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL,
> -			&supportedHWLevel, 1);
> +	staticMetadata_->addEntry(ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL,
> +				  &supportedHWLevel, 1);
>
>  	/* Request static metadata. */
>  	int32_t partialResultCount = 1;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_REQUEST_PARTIAL_RESULT_COUNT,
> -			&partialResultCount, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_REQUEST_PARTIAL_RESULT_COUNT,
> +				  &partialResultCount, 1);
>
>  	uint8_t maxPipelineDepth = 2;
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_REQUEST_PIPELINE_MAX_DEPTH,
> -			&maxPipelineDepth, 1);
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_REQUEST_PIPELINE_MAX_DEPTH,
> +				  &maxPipelineDepth, 1);
>
>  	std::vector<uint8_t> availableCapabilities = {
>  		ANDROID_REQUEST_AVAILABLE_CAPABILITIES_BACKWARD_COMPATIBLE,
>  	};
> -	ret = add_camera_metadata_entry(staticMetadata_,
> -			ANDROID_REQUEST_AVAILABLE_CAPABILITIES,
> -			availableCapabilities.data(),
> -			availableCapabilities.size());
> -	METADATA_ASSERT(ret);
> +	staticMetadata_->addEntry(ANDROID_REQUEST_AVAILABLE_CAPABILITIES,
> +				  availableCapabilities.data(),
> +				  availableCapabilities.size());
> +
> +	if (!staticMetadata_->isValid()) {
> +		delete staticMetadata_;
> +		staticMetadata_ = nullptr;
> +		return nullptr;
> +	}
>
> -	return staticMetadata_;
> +	return staticMetadata_->get();
>  }
>
>  /*
> @@ -513,8 +440,6 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
>   */
>  const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
>  {
> -	int ret;
> -
>  	/*
>  	 * \todo Inspect type and pick the right metadata pack.
>  	 * As of now just use a single one for all templates.
> @@ -545,89 +470,73 @@ const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
>  	}
>
>  	if (requestTemplate_)
> -		return requestTemplate_;
> +		return requestTemplate_->get();
>
>  	/*
>  	 * \todo Keep this in sync with the actual number of entries.
>  	 * Currently: 12 entries, 15 bytes
>  	 */
> -	requestTemplate_ = allocate_camera_metadata(15, 20);
> +	requestTemplate_ = new CameraMetadata(15, 20);
>  	if (!requestTemplate_) {
>  		LOG(HAL, Error) << "Failed to allocate template metadata";
> +		delete requestTemplate_;
> +		requestTemplate_ = nullptr;

Empty line before return ?

>  		return nullptr;
>  	}
>
>  	uint8_t aeMode = ANDROID_CONTROL_AE_MODE_ON;
> -	ret = add_camera_metadata_entry(requestTemplate_,
> -			ANDROID_CONTROL_AE_MODE,
> -			&aeMode, 1);
> -	METADATA_ASSERT(ret);
> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_MODE,
> +				   &aeMode, 1);

This and many others entries here and below fit in 1 line.

>
>  	int32_t aeExposureCompensation = 0;
> -	ret = add_camera_metadata_entry(requestTemplate_,
> -			ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION,
> -			&aeExposureCompensation, 1);
> -	METADATA_ASSERT(ret);
> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION,
> +				   &aeExposureCompensation, 1);
>
>  	uint8_t aePrecaptureTrigger = ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER_IDLE;
> -	ret = add_camera_metadata_entry(requestTemplate_,
> -			ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER,
> -			&aePrecaptureTrigger, 1);
> -	METADATA_ASSERT(ret);
> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER,
> +				   &aePrecaptureTrigger, 1);
>
>  	uint8_t aeLock = ANDROID_CONTROL_AE_LOCK_OFF;
> -	ret = add_camera_metadata_entry(requestTemplate_,
> -			ANDROID_CONTROL_AE_LOCK,
> -			&aeLock, 1);
> -	METADATA_ASSERT(ret);
> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_LOCK,
> +				   &aeLock, 1);
>
>  	uint8_t afTrigger = ANDROID_CONTROL_AF_TRIGGER_IDLE;
> -	ret = add_camera_metadata_entry(requestTemplate_,
> -			ANDROID_CONTROL_AF_TRIGGER,
> -			&afTrigger, 1);
> -	METADATA_ASSERT(ret);
> +	requestTemplate_->addEntry(ANDROID_CONTROL_AF_TRIGGER,
> +				   &afTrigger, 1);
>
>  	uint8_t awbMode = ANDROID_CONTROL_AWB_MODE_AUTO;
> -	ret = add_camera_metadata_entry(requestTemplate_,
> -			ANDROID_CONTROL_AWB_MODE,
> -			&awbMode, 1);
> -	METADATA_ASSERT(ret);
> +	requestTemplate_->addEntry(ANDROID_CONTROL_AWB_MODE,
> +				   &awbMode, 1);
>
>  	uint8_t awbLock = ANDROID_CONTROL_AWB_LOCK_OFF;
> -	ret = add_camera_metadata_entry(requestTemplate_,
> -			ANDROID_CONTROL_AWB_LOCK,
> -			&awbLock, 1);
> -	METADATA_ASSERT(ret);
> +	requestTemplate_->addEntry(ANDROID_CONTROL_AWB_LOCK,
> +				   &awbLock, 1);
>
>  	uint8_t flashMode = ANDROID_FLASH_MODE_OFF;
> -	ret = add_camera_metadata_entry(requestTemplate_,
> -			ANDROID_FLASH_MODE,
> -			&flashMode, 1);
> -	METADATA_ASSERT(ret);
> +	requestTemplate_->addEntry(ANDROID_FLASH_MODE,
> +				   &flashMode, 1);
>
>  	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
> -	ret = add_camera_metadata_entry(requestTemplate_,
> -			ANDROID_STATISTICS_FACE_DETECT_MODE,
> -			&faceDetectMode, 1);
> -	METADATA_ASSERT(ret);
> +	requestTemplate_->addEntry(ANDROID_STATISTICS_FACE_DETECT_MODE,
> +				   &faceDetectMode, 1);
>
>  	uint8_t noiseReduction = ANDROID_NOISE_REDUCTION_MODE_OFF;
> -	ret = add_camera_metadata_entry(requestTemplate_,
> -			ANDROID_NOISE_REDUCTION_MODE, &noiseReduction, 1);
> -	METADATA_ASSERT(ret);
> +	requestTemplate_->addEntry(ANDROID_NOISE_REDUCTION_MODE,
> +				   &noiseReduction, 1);
>
>  	uint8_t aberrationMode = ANDROID_COLOR_CORRECTION_ABERRATION_MODE_OFF;
> -	ret = add_camera_metadata_entry(requestTemplate_,
> -			ANDROID_COLOR_CORRECTION_ABERRATION_MODE,
> -			&aberrationMode, 1);
> -	METADATA_ASSERT(ret);
> +	requestTemplate_->addEntry(ANDROID_COLOR_CORRECTION_ABERRATION_MODE,
> +				   &aberrationMode, 1);
> +
> +	requestTemplate_->addEntry(ANDROID_CONTROL_CAPTURE_INTENT,
> +				   &captureIntent, 1);
>
> -	ret = add_camera_metadata_entry(requestTemplate_,
> -			ANDROID_CONTROL_CAPTURE_INTENT,
> -			&captureIntent, 1);
> -	METADATA_ASSERT(ret);
> +	if (!requestTemplate_->isValid()) {
> +		delete requestTemplate_;
> +		requestTemplate_ = nullptr;

You should return nullptr here, otherwise the below requestTemplate_->get();
will de-reference a nullptr.

> +	}
>
> -	return requestTemplate_;
> +	return requestTemplate_->get();
>  }
>
>  /*
> @@ -799,7 +708,7 @@ void CameraDevice::requestComplete(Request *request,
>  {
>  	Buffer *libcameraBuffer = buffers.begin()->second;
>  	camera3_buffer_status status = CAMERA3_BUFFER_STATUS_OK;
> -	camera_metadata_t *resultMetadata = nullptr;
> +	std::unique_ptr<CameraMetadata> resultMetadata;
>
>  	if (request->status() != Request::RequestComplete) {
>  		LOG(HAL, Error) << "Request not succesfully completed: "
> @@ -837,16 +746,12 @@ void CameraDevice::requestComplete(Request *request,
>  		captureResult.partial_result = 1;
>  		resultMetadata = getResultMetadata(descriptor->frameNumber,
>  						   libcameraBuffer->timestamp());
> -		captureResult.result = resultMetadata;
> +		captureResult.result = resultMetadata->get();
>  	}
>
>  	callbacks_->process_capture_result(callbacks_, &captureResult);
>
>  	delete descriptor;
> -	if (resultMetadata)
> -		free_camera_metadata(resultMetadata);
> -
> -	return;
>  }
>
>  void CameraDevice::notifyShutter(uint32_t frameNumber, uint64_t timestamp)
> @@ -875,89 +780,63 @@ void CameraDevice::notifyError(uint32_t frameNumber, camera3_stream_t *stream)
>  /*
>   * Produce a set of fixed result metadata.
>   */
> -camera_metadata_t *CameraDevice::getResultMetadata(int frame_number,
> -						   int64_t timestamp)
> +std::unique_ptr<CameraMetadata> CameraDevice::getResultMetadata(int frame_number,

Not a fan of smart pointers, you know already. How does this work?
Because the compiler applies copy-elision or because of the move
semantic applied on the return value?

Anway. it saves 2 lines in the caller but makes the code more
difficult to follow in my opinion.

> +								int64_t timestamp)
>  {
> -	int ret;
> -
>  	/*
>  	 * \todo Keep this in sync with the actual number of entries.
>  	 * Currently: 13 entries, 36 bytes
>  	 */
> -	camera_metadata_t *resultMetadata = allocate_camera_metadata(15, 50);
> +	std::unique_ptr<CameraMetadata> resultMetadata =
> +		utils::make_unique<CameraMetadata>(15, 50);
> +	if (!resultMetadata->isValid()) {
> +		LOG(HAL, Error) << "Failed to allocate static metadata";
> +		return nullptr;
> +	}
>
>  	const uint8_t ae_state = ANDROID_CONTROL_AE_STATE_CONVERGED;
> -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AE_STATE,
> -					&ae_state, 1);
> -	METADATA_ASSERT(ret);
> +	resultMetadata->addEntry(ANDROID_CONTROL_AE_STATE, &ae_state, 1);
>
>  	const uint8_t ae_lock = ANDROID_CONTROL_AE_LOCK_OFF;
> -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AE_LOCK,
> -					&ae_lock, 1);
> -	METADATA_ASSERT(ret);
> +	resultMetadata->addEntry(ANDROID_CONTROL_AE_LOCK, &ae_lock, 1);
>
>  	uint8_t af_state = ANDROID_CONTROL_AF_STATE_INACTIVE;
> -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AF_STATE,
> -					&af_state, 1);
> -	METADATA_ASSERT(ret);
> +	resultMetadata->addEntry(ANDROID_CONTROL_AF_STATE, &af_state, 1);
>
>  	const uint8_t awb_state = ANDROID_CONTROL_AWB_STATE_CONVERGED;
> -	ret = add_camera_metadata_entry(resultMetadata,
> -					ANDROID_CONTROL_AWB_STATE,
> -					&awb_state, 1);
> -	METADATA_ASSERT(ret);
> +	resultMetadata->addEntry(ANDROID_CONTROL_AWB_STATE, &awb_state, 1);
>
>  	const uint8_t awb_lock = ANDROID_CONTROL_AWB_LOCK_OFF;
> -	ret = add_camera_metadata_entry(resultMetadata,
> -					ANDROID_CONTROL_AWB_LOCK,
> -					&awb_lock, 1);
> -	METADATA_ASSERT(ret);
> +	resultMetadata->addEntry(ANDROID_CONTROL_AWB_LOCK, &awb_lock, 1);
>
>  	const uint8_t lens_state = ANDROID_LENS_STATE_STATIONARY;
> -	ret = add_camera_metadata_entry(resultMetadata,
> -					ANDROID_LENS_STATE,
> -					&lens_state, 1);
> -	METADATA_ASSERT(ret);
> +	resultMetadata->addEntry(ANDROID_LENS_STATE, &lens_state, 1);
>
>  	int32_t sensorSizes[] = {
>  		0, 0, 2560, 1920,
>  	};
> -	ret = add_camera_metadata_entry(resultMetadata,
> -					ANDROID_SCALER_CROP_REGION,
> -					sensorSizes, 4);
> -	METADATA_ASSERT(ret);
> +	resultMetadata->addEntry(ANDROID_SCALER_CROP_REGION, sensorSizes, 4);
>
> -	ret = add_camera_metadata_entry(resultMetadata,
> -					ANDROID_SENSOR_TIMESTAMP,
> -					&timestamp, 1);
> -	METADATA_ASSERT(ret);
> +	resultMetadata->addEntry(ANDROID_SENSOR_TIMESTAMP, &timestamp, 1);
>
>  	/* 33.3 msec */
>  	const int64_t rolling_shutter_skew = 33300000;
> -	ret = add_camera_metadata_entry(resultMetadata,
> -					ANDROID_SENSOR_ROLLING_SHUTTER_SKEW,
> -					&rolling_shutter_skew, 1);
> -	METADATA_ASSERT(ret);
> +	resultMetadata->addEntry(ANDROID_SENSOR_ROLLING_SHUTTER_SKEW,
> +				 &rolling_shutter_skew, 1);
>
>  	/* 16.6 msec */
>  	const int64_t exposure_time = 16600000;
> -	ret = add_camera_metadata_entry(resultMetadata,
> -					ANDROID_SENSOR_EXPOSURE_TIME,
> -					&exposure_time, 1);
> -	METADATA_ASSERT(ret);
> +	resultMetadata->addEntry(ANDROID_SENSOR_EXPOSURE_TIME,
> +				 &exposure_time, 1);
>
>  	const uint8_t lens_shading_map_mode =
>  				ANDROID_STATISTICS_LENS_SHADING_MAP_MODE_OFF;
> -	ret = add_camera_metadata_entry(resultMetadata,
> -					ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
> -					&lens_shading_map_mode, 1);
> -	METADATA_ASSERT(ret);
> +	resultMetadata->addEntry(ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
> +				 &lens_shading_map_mode, 1);
>
>  	const uint8_t scene_flicker = ANDROID_STATISTICS_SCENE_FLICKER_NONE;
> -	ret = add_camera_metadata_entry(resultMetadata,
> -					ANDROID_STATISTICS_SCENE_FLICKER,
> -					&scene_flicker, 1);
> -	METADATA_ASSERT(ret);
> +	resultMetadata->addEntry(ANDROID_STATISTICS_SCENE_FLICKER,
> +				 &scene_flicker, 1);

Shouldn't you check if the metadata pack is valid ?

Thanks
  j

>
>  	return resultMetadata;
>  }
> diff --git a/src/android/camera_device.h b/src/android/camera_device.h
> index 7897ba9dc5c7..65ba877a02ea 100644
> --- a/src/android/camera_device.h
> +++ b/src/android/camera_device.h
> @@ -19,13 +19,7 @@
>
>  #include "message.h"
>
> -#define METADATA_ASSERT(_r)		\
> -	do {				\
> -		if (!(_r)) break;	\
> -		LOG(HAL, Error) << "Error: " << __func__ << ":" << __LINE__; \
> -		return nullptr;		\
> -	} while(0);
> -
> +class CameraMetadata;
>  class ThreadRpc;
>
>  class CameraDevice : public libcamera::Object
> @@ -59,14 +53,15 @@ private:
>
>  	void notifyShutter(uint32_t frameNumber, uint64_t timestamp);
>  	void notifyError(uint32_t frameNumber, camera3_stream_t *stream);
> -	camera_metadata_t *getResultMetadata(int frame_number, int64_t timestamp);
> +	std::unique_ptr<CameraMetadata> getResultMetadata(int frame_number,
> +							  int64_t timestamp);
>
>  	bool running_;
>  	std::shared_ptr<libcamera::Camera> camera_;
>  	std::unique_ptr<libcamera::CameraConfiguration> config_;
>
> -	camera_metadata_t *staticMetadata_;
> -	camera_metadata_t *requestTemplate_;
> +	CameraMetadata *staticMetadata_;
> +	CameraMetadata *requestTemplate_;
>  	const camera3_callback_ops_t *callbacks_;
>  };
>
> --
> 2.23.0
>
> _______________________________________________
> libcamera-devel mailing list
> libcamera-devel@lists.libcamera.org
> https://lists.libcamera.org/listinfo/libcamera-devel
Laurent Pinchart Sept. 5, 2019, 9:36 a.m. UTC | #2
Hi Jacopo,

On Thu, Sep 05, 2019 at 10:18:28AM +0200, Jacopo Mondi wrote:
> On Thu, Sep 05, 2019 at 09:47:34AM +0200, Jacopo Mondi wrote:
> > From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >
> > Simplify the implementation of metadata handling in the CameraDevice
> > class by using the new CameraMetadata helper class.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> >  src/android/camera_device.cpp | 507 +++++++++++++---------------------
> >  src/android/camera_device.h   |  15 +-
> >  2 files changed, 198 insertions(+), 324 deletions(-)
> >
> > diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
> > index 5f8d19b9ef3d..475fa2404421 100644
> > --- a/src/android/camera_device.cpp
> > +++ b/src/android/camera_device.cpp
> > @@ -7,10 +7,10 @@
> >
> >  #include "camera_device.h"
> >
> > -#include <system/camera_metadata.h>
> > -
> >  #include "log.h"
> > +#include "utils.h"
> >
> > +#include "camera_metadata.h"
> >  #include "thread_rpc.h"
> >
> >  using namespace libcamera;
> > @@ -59,12 +59,10 @@ CameraDevice::CameraDevice(unsigned int id, const std::shared_ptr<Camera> &camer
> >  CameraDevice::~CameraDevice()
> >  {
> >  	if (staticMetadata_)
> > -		free_camera_metadata(staticMetadata_);
> > -	staticMetadata_ = nullptr;
> > +		delete staticMetadata_;
> >
> >  	if (requestTemplate_)
> > -		free_camera_metadata(requestTemplate_);
> > -	requestTemplate_ = nullptr;
> > +		delete requestTemplate_;
> >  }
> >
> >  /*
> > @@ -117,10 +115,8 @@ void CameraDevice::setCallbacks(const camera3_callback_ops_t *callbacks)
> >   */
> >  camera_metadata_t *CameraDevice::getStaticMetadata()
> >  {
> > -	int ret;
> > -
> >  	if (staticMetadata_)
> > -		return staticMetadata_;
> > +		return staticMetadata_->get();
> >
> >  	/*
> >  	 * The here reported metadata are enough to implement a basic capture
> > @@ -132,16 +128,21 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> >  	 * \todo Keep this in sync with the actual number of entries.
> >  	 * Currently: 46 entries, 390 bytes
> >  	 */
> > -	staticMetadata_ = allocate_camera_metadata(50, 500);
> > +	staticMetadata_ = new CameraMetadata(50, 500);
> > +	if (!staticMetadata_->isValid()) {
> > +		LOG(HAL, Error) << "Failed to allocate static metadata";
> > +		delete staticMetadata_;
> > +		staticMetadata_ = nullptr;
> > +		return nullptr;
> 
> Empty line before return?

I don't mind either way, but I haven't added one as the delete,
assignment to nullptr and return nullptr are logically grouped in my
opinion. Feel free to add a blank line if you prefer.

> > +	}
> >
> >  	/* Color correction static metadata. */
> >  	std::vector<uint8_t> aberrationModes = {
> >  		ANDROID_COLOR_CORRECTION_ABERRATION_MODE_OFF,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES,
> > -			aberrationModes.data(), aberrationModes.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES,
> > +				  aberrationModes.data(),
> > +				  aberrationModes.size());
> >
> >  	/* Control static metadata. */
> >  	std::vector<uint8_t> aeAvailableAntiBandingModes = {
> > @@ -150,294 +151,228 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> >  		ANDROID_CONTROL_AE_ANTIBANDING_MODE_60HZ,
> >  		ANDROID_CONTROL_AE_ANTIBANDING_MODE_AUTO,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES,
> > -			aeAvailableAntiBandingModes.data(),
> > -			aeAvailableAntiBandingModes.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES,
> > +				  aeAvailableAntiBandingModes.data(),
> > +				  aeAvailableAntiBandingModes.size());
> >
> >  	std::vector<uint8_t> aeAvailableModes = {
> >  		ANDROID_CONTROL_AE_MODE_ON,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_CONTROL_AE_AVAILABLE_MODES,
> > -			aeAvailableModes.data(), aeAvailableModes.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_MODES,
> > +				  aeAvailableModes.data(),
> > +				  aeAvailableModes.size());
> >
> >  	std::vector<int32_t> availableAeFpsTarget = {
> >  		15, 30,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES,
> > -			availableAeFpsTarget.data(),
> > -			availableAeFpsTarget.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES,
> > +				  availableAeFpsTarget.data(),
> > +				  availableAeFpsTarget.size());
> >
> >  	std::vector<int32_t> aeCompensationRange = {
> >  		0, 0,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_CONTROL_AE_COMPENSATION_RANGE,
> > -			aeCompensationRange.data(),
> > -			aeCompensationRange.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_COMPENSATION_RANGE,
> > +				  aeCompensationRange.data(),
> > +				  aeCompensationRange.size());
> >
> >  	const camera_metadata_rational_t aeCompensationStep[] = {
> >  		{ 0, 1 }
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_CONTROL_AE_COMPENSATION_STEP,
> > -			aeCompensationStep, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_COMPENSATION_STEP,
> > +				  aeCompensationStep, 1);
> >
> >  	std::vector<uint8_t> availableAfModes = {
> >  		ANDROID_CONTROL_AF_MODE_OFF,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_CONTROL_AF_AVAILABLE_MODES,
> > -			availableAfModes.data(), availableAfModes.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_CONTROL_AF_AVAILABLE_MODES,
> > +				  availableAfModes.data(),
> > +				  availableAfModes.size());
> >
> >  	std::vector<uint8_t> availableEffects = {
> >  		ANDROID_CONTROL_EFFECT_MODE_OFF,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_CONTROL_AVAILABLE_EFFECTS,
> > -			availableEffects.data(), availableEffects.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_EFFECTS,
> > +				  availableEffects.data(),
> > +				  availableEffects.size());
> >
> >  	std::vector<uint8_t> availableSceneModes = {
> >  		ANDROID_CONTROL_SCENE_MODE_DISABLED,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_CONTROL_AVAILABLE_SCENE_MODES,
> > -			availableSceneModes.data(), availableSceneModes.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_SCENE_MODES,
> > +				  availableSceneModes.data(),
> > +				  availableSceneModes.size());
> >
> >  	std::vector<uint8_t> availableStabilizationModes = {
> >  		ANDROID_CONTROL_VIDEO_STABILIZATION_MODE_OFF,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES,
> > -			availableStabilizationModes.data(),
> > -			availableStabilizationModes.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES,
> > +				  availableStabilizationModes.data(),
> > +				  availableStabilizationModes.size());
> >
> >  	std::vector<uint8_t> availableAwbModes = {
> >  		ANDROID_CONTROL_AWB_MODE_OFF,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_CONTROL_AWB_AVAILABLE_MODES,
> > -			availableAwbModes.data(), availableAwbModes.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_CONTROL_AWB_AVAILABLE_MODES,
> > +				  availableAwbModes.data(),
> > +				  availableAwbModes.size());
> >
> >  	std::vector<int32_t> availableMaxRegions = {
> >  		0, 0, 0,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_CONTROL_MAX_REGIONS,
> > -			availableMaxRegions.data(), availableMaxRegions.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_CONTROL_MAX_REGIONS,
> > +				  availableMaxRegions.data(),
> > +				  availableMaxRegions.size());
> >
> >  	std::vector<uint8_t> sceneModesOverride = {
> >  		ANDROID_CONTROL_AE_MODE_ON,
> >  		ANDROID_CONTROL_AWB_MODE_AUTO,
> >  		ANDROID_CONTROL_AF_MODE_AUTO,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_CONTROL_SCENE_MODE_OVERRIDES,
> > -			sceneModesOverride.data(), sceneModesOverride.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_CONTROL_SCENE_MODE_OVERRIDES,
> > +				  sceneModesOverride.data(),
> > +				  sceneModesOverride.size());
> >
> >  	uint8_t aeLockAvailable = ANDROID_CONTROL_AE_LOCK_AVAILABLE_FALSE;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_CONTROL_AE_LOCK_AVAILABLE,
> > -			&aeLockAvailable, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_LOCK_AVAILABLE,
> > +				  &aeLockAvailable, 1);
> >
> >  	uint8_t awbLockAvailable = ANDROID_CONTROL_AWB_LOCK_AVAILABLE_FALSE;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
> > -			&awbLockAvailable, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
> > +				  &awbLockAvailable, 1);
> >
> >  	char availableControlModes = ANDROID_CONTROL_MODE_AUTO;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_CONTROL_AVAILABLE_MODES,
> > -			&availableControlModes, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_MODES,
> > +				  &availableControlModes, 1);
> >
> >  	/* JPEG static metadata. */
> >  	std::vector<int32_t> availableThumbnailSizes = {
> >  		0, 0,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
> > -			availableThumbnailSizes.data(),
> > -			availableThumbnailSizes.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
> > +				  availableThumbnailSizes.data(),
> > +				  availableThumbnailSizes.size());
> >
> >  	/* Sensor static metadata. */
> >  	int32_t pixelArraySize[] = {
> >  		2592, 1944,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -				ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
> > -				&pixelArraySize, 2);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
> > +				  &pixelArraySize, 2);
> >
> >  	int32_t sensorSizes[] = {
> >  		0, 0, 2560, 1920,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -				ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
> > -				&sensorSizes, 4);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
> > +				  &sensorSizes, 4);
> >
> >  	int32_t sensitivityRange[] = {
> >  		32, 2400,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -				ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
> > -				&sensitivityRange, 2);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
> > +				  &sensitivityRange, 2);
> >
> >  	uint16_t filterArr = ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT_GRBG;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -				ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
> > -				&filterArr, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
> > +				  &filterArr, 1);
> >
> >  	int64_t exposureTimeRange[] = {
> >  		100000, 200000000,
> >  	};
> 
> I've been thinking for a while to stabilize on the use of std::vector in
> place of arrays, so e can always use .data() and .size() and have
> guaranteed we should only change the declaration and not the
> parameters to the addEntry() operation.
> 
> This might be a good time to do so. What do you think?

I've thought about it, and constructing a vector is a bit costly
compared to arrays. I'd rather used std::array<>, but that requires
specifying the size explicitly :-S I've been thinking about overloading
the addEntry() method, in order to be able to write

	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
				  { 100000, 200000000 });

I'm not sure if that will be possible as we need to handle different
data types, but I think it's worth a try. Other overloaded methods
should also be added for the arrays of a single element:

	staticMetadata_->addEntry(ANDROID_SENSOR_ORIENTATION, 0);

I would prefer handling the standardisation of vector vs. array in a
separate patch, when dealing with overloaded versions of addEntry(), as
this patch is big enough already.

> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -				ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> > -				&exposureTimeRange, 2);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> > +				  &exposureTimeRange, 2);
> >
> >  	int32_t orientation = 0;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -				ANDROID_SENSOR_ORIENTATION,
> > -				&orientation, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_SENSOR_ORIENTATION,
> > +				  &orientation, 1);
> 
> Fits in 1 line

I've kept it on two lines to use similar constructs through the whole
function, but I don't mind much, so please feel free to change it if you
prefer.

> >
> >  	std::vector<int32_t> testPatterModes = {
> >  		ANDROID_SENSOR_TEST_PATTERN_MODE_OFF,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -				ANDROID_SENSOR_AVAILABLE_TEST_PATTERN_MODES,
> > -				testPatterModes.data(), testPatterModes.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_SENSOR_AVAILABLE_TEST_PATTERN_MODES,
> > +				  testPatterModes.data(),
> > +				  testPatterModes.size());
> >
> >  	std::vector<float> physicalSize = {
> >  		2592, 1944,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -				ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
> > -				physicalSize.data(), physicalSize.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
> > +				  physicalSize.data(),
> > +				  physicalSize.size());
> 
> Fits in 1 line
> 
> >
> >  	uint8_t timestampSource = ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE_UNKNOWN;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE,
> > -			&timestampSource, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE,
> > +				  &timestampSource, 1);
> >
> >  	/* Statistics static metadata. */
> >  	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
> > -			&faceDetectMode, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
> > +				  &faceDetectMode, 1);
> >
> >  	int32_t maxFaceCount = 0;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
> > -			&maxFaceCount, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
> > +				  &maxFaceCount, 1);
> >
> >  	/* Sync static metadata. */
> >  	int32_t maxLatency = ANDROID_SYNC_MAX_LATENCY_UNKNOWN;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_SYNC_MAX_LATENCY, &maxLatency, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_SYNC_MAX_LATENCY, &maxLatency, 1);
> >
> >  	/* Flash static metadata. */
> >  	char flashAvailable = ANDROID_FLASH_INFO_AVAILABLE_FALSE;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_FLASH_INFO_AVAILABLE,
> > -			&flashAvailable, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_FLASH_INFO_AVAILABLE,
> > +				  &flashAvailable, 1);
> >
> >  	/* Lens static metadata. */
> >  	std::vector<float> lensApertures = {
> >  		2.53 / 100,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -				ANDROID_LENS_INFO_AVAILABLE_APERTURES,
> > -				lensApertures.data(), lensApertures.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_APERTURES,
> > +				  lensApertures.data(),
> > +				  lensApertures.size());
> >
> >  	uint8_t lensFacing = ANDROID_LENS_FACING_FRONT;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -				ANDROID_LENS_FACING, &lensFacing, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_LENS_FACING, &lensFacing, 1);
> >
> >  	std::vector<float> lensFocalLenghts = {
> >  		1,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -				ANDROID_LENS_INFO_AVAILABLE_FOCAL_LENGTHS,
> > -				lensFocalLenghts.data(),
> > -				lensFocalLenghts.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_FOCAL_LENGTHS,
> > +				  lensFocalLenghts.data(),
> > +				  lensFocalLenghts.size());
> >
> >  	std::vector<uint8_t> opticalStabilizations = {
> >  		ANDROID_LENS_OPTICAL_STABILIZATION_MODE_OFF,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -				ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
> > -				opticalStabilizations.data(),
> > -				opticalStabilizations.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
> > +				  opticalStabilizations.data(),
> > +				  opticalStabilizations.size());
> >
> >  	float hypeFocalDistance = 0;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -				ANDROID_LENS_INFO_HYPERFOCAL_DISTANCE,
> > -				&hypeFocalDistance, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_LENS_INFO_HYPERFOCAL_DISTANCE,
> > +				  &hypeFocalDistance, 1);
> >
> >  	float minFocusDistance = 0;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -				ANDROID_LENS_INFO_MINIMUM_FOCUS_DISTANCE,
> > -				&minFocusDistance, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_LENS_INFO_MINIMUM_FOCUS_DISTANCE,
> > +				  &minFocusDistance, 1);
> >
> >  	/* Noise reduction modes. */
> >  	uint8_t noiseReductionModes = ANDROID_NOISE_REDUCTION_MODE_OFF;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -				ANDROID_NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES,
> > -				&noiseReductionModes, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES,
> > +				  &noiseReductionModes, 1);
> >
> >  	/* Scaler static metadata. */
> >  	float maxDigitalZoom = 1;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_SCALER_AVAILABLE_MAX_DIGITAL_ZOOM,
> > -			&maxDigitalZoom, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_MAX_DIGITAL_ZOOM,
> > +				  &maxDigitalZoom, 1);
> >
> >  	std::vector<uint32_t> availableStreamFormats = {
> >  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB,
> >  		ANDROID_SCALER_AVAILABLE_FORMATS_YCbCr_420_888,
> >  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_SCALER_AVAILABLE_FORMATS,
> > -			availableStreamFormats.data(),
> > -			availableStreamFormats.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_FORMATS,
> > +				  availableStreamFormats.data(),
> > +				  availableStreamFormats.size());
> >
> >  	std::vector<uint32_t> availableStreamConfigurations = {
> >  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920,
> > @@ -447,65 +382,57 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> >  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED, 2560, 1920,
> >  		ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS_OUTPUT,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS,
> > -			availableStreamConfigurations.data(),
> > -			availableStreamConfigurations.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS,
> > +				  availableStreamConfigurations.data(),
> > +				  availableStreamConfigurations.size());
> >
> >  	std::vector<int64_t> availableStallDurations = {
> >  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920, 33333333,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_SCALER_AVAILABLE_STALL_DURATIONS,
> > -			availableStallDurations.data(),
> > -			availableStallDurations.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_STALL_DURATIONS,
> > +				  availableStallDurations.data(),
> > +				  availableStallDurations.size());
> >
> >  	std::vector<int64_t> minFrameDurations = {
> >  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920, 33333333,
> >  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED, 2560, 1920, 33333333,
> >  		ANDROID_SCALER_AVAILABLE_FORMATS_YCbCr_420_888, 2560, 1920, 33333333,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_SCALER_AVAILABLE_MIN_FRAME_DURATIONS,
> > -			minFrameDurations.data(), minFrameDurations.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_MIN_FRAME_DURATIONS,
> > +				  minFrameDurations.data(),
> > +				  minFrameDurations.size());
> >
> >  	uint8_t croppingType = ANDROID_SCALER_CROPPING_TYPE_CENTER_ONLY;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_SCALER_CROPPING_TYPE, &croppingType, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_SCALER_CROPPING_TYPE, &croppingType, 1);
> >
> >  	/* Info static metadata. */
> >  	uint8_t supportedHWLevel = ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL,
> > -			&supportedHWLevel, 1);
> > +	staticMetadata_->addEntry(ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL,
> > +				  &supportedHWLevel, 1);
> >
> >  	/* Request static metadata. */
> >  	int32_t partialResultCount = 1;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_REQUEST_PARTIAL_RESULT_COUNT,
> > -			&partialResultCount, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_REQUEST_PARTIAL_RESULT_COUNT,
> > +				  &partialResultCount, 1);
> >
> >  	uint8_t maxPipelineDepth = 2;
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_REQUEST_PIPELINE_MAX_DEPTH,
> > -			&maxPipelineDepth, 1);
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_REQUEST_PIPELINE_MAX_DEPTH,
> > +				  &maxPipelineDepth, 1);
> >
> >  	std::vector<uint8_t> availableCapabilities = {
> >  		ANDROID_REQUEST_AVAILABLE_CAPABILITIES_BACKWARD_COMPATIBLE,
> >  	};
> > -	ret = add_camera_metadata_entry(staticMetadata_,
> > -			ANDROID_REQUEST_AVAILABLE_CAPABILITIES,
> > -			availableCapabilities.data(),
> > -			availableCapabilities.size());
> > -	METADATA_ASSERT(ret);
> > +	staticMetadata_->addEntry(ANDROID_REQUEST_AVAILABLE_CAPABILITIES,
> > +				  availableCapabilities.data(),
> > +				  availableCapabilities.size());
> > +
> > +	if (!staticMetadata_->isValid()) {
> > +		delete staticMetadata_;
> > +		staticMetadata_ = nullptr;
> > +		return nullptr;
> > +	}
> >
> > -	return staticMetadata_;
> > +	return staticMetadata_->get();
> >  }
> >
> >  /*
> > @@ -513,8 +440,6 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> >   */
> >  const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
> >  {
> > -	int ret;
> > -
> >  	/*
> >  	 * \todo Inspect type and pick the right metadata pack.
> >  	 * As of now just use a single one for all templates.
> > @@ -545,89 +470,73 @@ const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
> >  	}
> >
> >  	if (requestTemplate_)
> > -		return requestTemplate_;
> > +		return requestTemplate_->get();
> >
> >  	/*
> >  	 * \todo Keep this in sync with the actual number of entries.
> >  	 * Currently: 12 entries, 15 bytes
> >  	 */
> > -	requestTemplate_ = allocate_camera_metadata(15, 20);
> > +	requestTemplate_ = new CameraMetadata(15, 20);
> >  	if (!requestTemplate_) {
> >  		LOG(HAL, Error) << "Failed to allocate template metadata";
> > +		delete requestTemplate_;
> > +		requestTemplate_ = nullptr;
> 
> Empty line before return ?
> 
> >  		return nullptr;
> >  	}
> >
> >  	uint8_t aeMode = ANDROID_CONTROL_AE_MODE_ON;
> > -	ret = add_camera_metadata_entry(requestTemplate_,
> > -			ANDROID_CONTROL_AE_MODE,
> > -			&aeMode, 1);
> > -	METADATA_ASSERT(ret);
> > +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_MODE,
> > +				   &aeMode, 1);
> 
> This and many others entries here and below fit in 1 line.
> 
> >
> >  	int32_t aeExposureCompensation = 0;
> > -	ret = add_camera_metadata_entry(requestTemplate_,
> > -			ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION,
> > -			&aeExposureCompensation, 1);
> > -	METADATA_ASSERT(ret);
> > +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION,
> > +				   &aeExposureCompensation, 1);
> >
> >  	uint8_t aePrecaptureTrigger = ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER_IDLE;
> > -	ret = add_camera_metadata_entry(requestTemplate_,
> > -			ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER,
> > -			&aePrecaptureTrigger, 1);
> > -	METADATA_ASSERT(ret);
> > +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER,
> > +				   &aePrecaptureTrigger, 1);
> >
> >  	uint8_t aeLock = ANDROID_CONTROL_AE_LOCK_OFF;
> > -	ret = add_camera_metadata_entry(requestTemplate_,
> > -			ANDROID_CONTROL_AE_LOCK,
> > -			&aeLock, 1);
> > -	METADATA_ASSERT(ret);
> > +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_LOCK,
> > +				   &aeLock, 1);
> >
> >  	uint8_t afTrigger = ANDROID_CONTROL_AF_TRIGGER_IDLE;
> > -	ret = add_camera_metadata_entry(requestTemplate_,
> > -			ANDROID_CONTROL_AF_TRIGGER,
> > -			&afTrigger, 1);
> > -	METADATA_ASSERT(ret);
> > +	requestTemplate_->addEntry(ANDROID_CONTROL_AF_TRIGGER,
> > +				   &afTrigger, 1);
> >
> >  	uint8_t awbMode = ANDROID_CONTROL_AWB_MODE_AUTO;
> > -	ret = add_camera_metadata_entry(requestTemplate_,
> > -			ANDROID_CONTROL_AWB_MODE,
> > -			&awbMode, 1);
> > -	METADATA_ASSERT(ret);
> > +	requestTemplate_->addEntry(ANDROID_CONTROL_AWB_MODE,
> > +				   &awbMode, 1);
> >
> >  	uint8_t awbLock = ANDROID_CONTROL_AWB_LOCK_OFF;
> > -	ret = add_camera_metadata_entry(requestTemplate_,
> > -			ANDROID_CONTROL_AWB_LOCK,
> > -			&awbLock, 1);
> > -	METADATA_ASSERT(ret);
> > +	requestTemplate_->addEntry(ANDROID_CONTROL_AWB_LOCK,
> > +				   &awbLock, 1);
> >
> >  	uint8_t flashMode = ANDROID_FLASH_MODE_OFF;
> > -	ret = add_camera_metadata_entry(requestTemplate_,
> > -			ANDROID_FLASH_MODE,
> > -			&flashMode, 1);
> > -	METADATA_ASSERT(ret);
> > +	requestTemplate_->addEntry(ANDROID_FLASH_MODE,
> > +				   &flashMode, 1);
> >
> >  	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
> > -	ret = add_camera_metadata_entry(requestTemplate_,
> > -			ANDROID_STATISTICS_FACE_DETECT_MODE,
> > -			&faceDetectMode, 1);
> > -	METADATA_ASSERT(ret);
> > +	requestTemplate_->addEntry(ANDROID_STATISTICS_FACE_DETECT_MODE,
> > +				   &faceDetectMode, 1);
> >
> >  	uint8_t noiseReduction = ANDROID_NOISE_REDUCTION_MODE_OFF;
> > -	ret = add_camera_metadata_entry(requestTemplate_,
> > -			ANDROID_NOISE_REDUCTION_MODE, &noiseReduction, 1);
> > -	METADATA_ASSERT(ret);
> > +	requestTemplate_->addEntry(ANDROID_NOISE_REDUCTION_MODE,
> > +				   &noiseReduction, 1);
> >
> >  	uint8_t aberrationMode = ANDROID_COLOR_CORRECTION_ABERRATION_MODE_OFF;
> > -	ret = add_camera_metadata_entry(requestTemplate_,
> > -			ANDROID_COLOR_CORRECTION_ABERRATION_MODE,
> > -			&aberrationMode, 1);
> > -	METADATA_ASSERT(ret);
> > +	requestTemplate_->addEntry(ANDROID_COLOR_CORRECTION_ABERRATION_MODE,
> > +				   &aberrationMode, 1);
> > +
> > +	requestTemplate_->addEntry(ANDROID_CONTROL_CAPTURE_INTENT,
> > +				   &captureIntent, 1);
> >
> > -	ret = add_camera_metadata_entry(requestTemplate_,
> > -			ANDROID_CONTROL_CAPTURE_INTENT,
> > -			&captureIntent, 1);
> > -	METADATA_ASSERT(ret);
> > +	if (!requestTemplate_->isValid()) {
> > +		delete requestTemplate_;
> > +		requestTemplate_ = nullptr;
> 
> You should return nullptr here, otherwise the below requestTemplate_->get();
> will de-reference a nullptr.

Absolutely, my bad.

> > +	}
> >
> > -	return requestTemplate_;
> > +	return requestTemplate_->get();
> >  }
> >
> >  /*
> > @@ -799,7 +708,7 @@ void CameraDevice::requestComplete(Request *request,
> >  {
> >  	Buffer *libcameraBuffer = buffers.begin()->second;
> >  	camera3_buffer_status status = CAMERA3_BUFFER_STATUS_OK;
> > -	camera_metadata_t *resultMetadata = nullptr;
> > +	std::unique_ptr<CameraMetadata> resultMetadata;
> >
> >  	if (request->status() != Request::RequestComplete) {
> >  		LOG(HAL, Error) << "Request not succesfully completed: "
> > @@ -837,16 +746,12 @@ void CameraDevice::requestComplete(Request *request,
> >  		captureResult.partial_result = 1;
> >  		resultMetadata = getResultMetadata(descriptor->frameNumber,
> >  						   libcameraBuffer->timestamp());
> > -		captureResult.result = resultMetadata;
> > +		captureResult.result = resultMetadata->get();
> >  	}
> >
> >  	callbacks_->process_capture_result(callbacks_, &captureResult);
> >
> >  	delete descriptor;
> > -	if (resultMetadata)
> > -		free_camera_metadata(resultMetadata);
> > -
> > -	return;
> >  }
> >
> >  void CameraDevice::notifyShutter(uint32_t frameNumber, uint64_t timestamp)
> > @@ -875,89 +780,63 @@ void CameraDevice::notifyError(uint32_t frameNumber, camera3_stream_t *stream)
> >  /*
> >   * Produce a set of fixed result metadata.
> >   */
> > -camera_metadata_t *CameraDevice::getResultMetadata(int frame_number,
> > -						   int64_t timestamp)
> > +std::unique_ptr<CameraMetadata> CameraDevice::getResultMetadata(int frame_number,
> 
> Not a fan of smart pointers, you know already. How does this work?
> Because the compiler applies copy-elision or because of the move
> semantic applied on the return value?

std::unique_ptr<> has an operator= that takes an rvalue reference to
another std::unique_ptr<>, and uses move semantic. As explained in
https://en.cppreference.com/w/cpp/language/value_category, an rvalue is
either a prvalue or an xvalue, and a prvalue can be "a function call or
an overloaded operator expression, whose return type is non-reference".
As far as I can tell, that's why we don't need an std::move() in the
caller.

> Anway. it saves 2 lines in the caller but makes the code more
> difficult to follow in my opinion.

I think we should standardise as much as possible on std::unique_ptr<>
when passing ownership of a returned pointer. That's documented in
Documentation/coding-style.rst.

> > +								int64_t timestamp)
> >  {
> > -	int ret;
> > -
> >  	/*
> >  	 * \todo Keep this in sync with the actual number of entries.
> >  	 * Currently: 13 entries, 36 bytes
> >  	 */
> > -	camera_metadata_t *resultMetadata = allocate_camera_metadata(15, 50);
> > +	std::unique_ptr<CameraMetadata> resultMetadata =
> > +		utils::make_unique<CameraMetadata>(15, 50);
> > +	if (!resultMetadata->isValid()) {
> > +		LOG(HAL, Error) << "Failed to allocate static metadata";
> > +		return nullptr;
> > +	}
> >
> >  	const uint8_t ae_state = ANDROID_CONTROL_AE_STATE_CONVERGED;
> > -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AE_STATE,
> > -					&ae_state, 1);
> > -	METADATA_ASSERT(ret);
> > +	resultMetadata->addEntry(ANDROID_CONTROL_AE_STATE, &ae_state, 1);
> >
> >  	const uint8_t ae_lock = ANDROID_CONTROL_AE_LOCK_OFF;
> > -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AE_LOCK,
> > -					&ae_lock, 1);
> > -	METADATA_ASSERT(ret);
> > +	resultMetadata->addEntry(ANDROID_CONTROL_AE_LOCK, &ae_lock, 1);
> >
> >  	uint8_t af_state = ANDROID_CONTROL_AF_STATE_INACTIVE;
> > -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AF_STATE,
> > -					&af_state, 1);
> > -	METADATA_ASSERT(ret);
> > +	resultMetadata->addEntry(ANDROID_CONTROL_AF_STATE, &af_state, 1);
> >
> >  	const uint8_t awb_state = ANDROID_CONTROL_AWB_STATE_CONVERGED;
> > -	ret = add_camera_metadata_entry(resultMetadata,
> > -					ANDROID_CONTROL_AWB_STATE,
> > -					&awb_state, 1);
> > -	METADATA_ASSERT(ret);
> > +	resultMetadata->addEntry(ANDROID_CONTROL_AWB_STATE, &awb_state, 1);
> >
> >  	const uint8_t awb_lock = ANDROID_CONTROL_AWB_LOCK_OFF;
> > -	ret = add_camera_metadata_entry(resultMetadata,
> > -					ANDROID_CONTROL_AWB_LOCK,
> > -					&awb_lock, 1);
> > -	METADATA_ASSERT(ret);
> > +	resultMetadata->addEntry(ANDROID_CONTROL_AWB_LOCK, &awb_lock, 1);
> >
> >  	const uint8_t lens_state = ANDROID_LENS_STATE_STATIONARY;
> > -	ret = add_camera_metadata_entry(resultMetadata,
> > -					ANDROID_LENS_STATE,
> > -					&lens_state, 1);
> > -	METADATA_ASSERT(ret);
> > +	resultMetadata->addEntry(ANDROID_LENS_STATE, &lens_state, 1);
> >
> >  	int32_t sensorSizes[] = {
> >  		0, 0, 2560, 1920,
> >  	};
> > -	ret = add_camera_metadata_entry(resultMetadata,
> > -					ANDROID_SCALER_CROP_REGION,
> > -					sensorSizes, 4);
> > -	METADATA_ASSERT(ret);
> > +	resultMetadata->addEntry(ANDROID_SCALER_CROP_REGION, sensorSizes, 4);
> >
> > -	ret = add_camera_metadata_entry(resultMetadata,
> > -					ANDROID_SENSOR_TIMESTAMP,
> > -					&timestamp, 1);
> > -	METADATA_ASSERT(ret);
> > +	resultMetadata->addEntry(ANDROID_SENSOR_TIMESTAMP, &timestamp, 1);
> >
> >  	/* 33.3 msec */
> >  	const int64_t rolling_shutter_skew = 33300000;
> > -	ret = add_camera_metadata_entry(resultMetadata,
> > -					ANDROID_SENSOR_ROLLING_SHUTTER_SKEW,
> > -					&rolling_shutter_skew, 1);
> > -	METADATA_ASSERT(ret);
> > +	resultMetadata->addEntry(ANDROID_SENSOR_ROLLING_SHUTTER_SKEW,
> > +				 &rolling_shutter_skew, 1);
> >
> >  	/* 16.6 msec */
> >  	const int64_t exposure_time = 16600000;
> > -	ret = add_camera_metadata_entry(resultMetadata,
> > -					ANDROID_SENSOR_EXPOSURE_TIME,
> > -					&exposure_time, 1);
> > -	METADATA_ASSERT(ret);
> > +	resultMetadata->addEntry(ANDROID_SENSOR_EXPOSURE_TIME,
> > +				 &exposure_time, 1);
> >
> >  	const uint8_t lens_shading_map_mode =
> >  				ANDROID_STATISTICS_LENS_SHADING_MAP_MODE_OFF;
> > -	ret = add_camera_metadata_entry(resultMetadata,
> > -					ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
> > -					&lens_shading_map_mode, 1);
> > -	METADATA_ASSERT(ret);
> > +	resultMetadata->addEntry(ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
> > +				 &lens_shading_map_mode, 1);
> >
> >  	const uint8_t scene_flicker = ANDROID_STATISTICS_SCENE_FLICKER_NONE;
> > -	ret = add_camera_metadata_entry(resultMetadata,
> > -					ANDROID_STATISTICS_SCENE_FLICKER,
> > -					&scene_flicker, 1);
> > -	METADATA_ASSERT(ret);
> > +	resultMetadata->addEntry(ANDROID_STATISTICS_SCENE_FLICKER,
> > +				 &scene_flicker, 1);
> 
> Shouldn't you check if the metadata pack is valid ?

Good point. Should we check here or in the caller ? As the caller would
then need a nullptr check I'm tempted to do so in the caller. Actually,
without a change to the code, the caller will operate correctly I
believe

                resultMetadata = getResultMetadata(descriptor->frameNumber,
                                                   libcameraBuffer->timestamp());
                captureResult.result = resultMetadata->get();

which will set captureResult.result to nullptr if resultMetadata is not
valid.

> >
> >  	return resultMetadata;
> >  }
> > diff --git a/src/android/camera_device.h b/src/android/camera_device.h
> > index 7897ba9dc5c7..65ba877a02ea 100644
> > --- a/src/android/camera_device.h
> > +++ b/src/android/camera_device.h
> > @@ -19,13 +19,7 @@
> >
> >  #include "message.h"
> >
> > -#define METADATA_ASSERT(_r)		\
> > -	do {				\
> > -		if (!(_r)) break;	\
> > -		LOG(HAL, Error) << "Error: " << __func__ << ":" << __LINE__; \
> > -		return nullptr;		\
> > -	} while(0);
> > -
> > +class CameraMetadata;
> >  class ThreadRpc;
> >
> >  class CameraDevice : public libcamera::Object
> > @@ -59,14 +53,15 @@ private:
> >
> >  	void notifyShutter(uint32_t frameNumber, uint64_t timestamp);
> >  	void notifyError(uint32_t frameNumber, camera3_stream_t *stream);
> > -	camera_metadata_t *getResultMetadata(int frame_number, int64_t timestamp);
> > +	std::unique_ptr<CameraMetadata> getResultMetadata(int frame_number,
> > +							  int64_t timestamp);
> >
> >  	bool running_;
> >  	std::shared_ptr<libcamera::Camera> camera_;
> >  	std::unique_ptr<libcamera::CameraConfiguration> config_;
> >
> > -	camera_metadata_t *staticMetadata_;
> > -	camera_metadata_t *requestTemplate_;
> > +	CameraMetadata *staticMetadata_;
> > +	CameraMetadata *requestTemplate_;
> >  	const camera3_callback_ops_t *callbacks_;
> >  };
> >
Jacopo Mondi Sept. 5, 2019, 9:52 a.m. UTC | #3
Hi Laurent,

On Thu, Sep 05, 2019 at 12:36:57PM +0300, Laurent Pinchart wrote:
> Hi Jacopo,
>
> On Thu, Sep 05, 2019 at 10:18:28AM +0200, Jacopo Mondi wrote:
> > On Thu, Sep 05, 2019 at 09:47:34AM +0200, Jacopo Mondi wrote:
> > > From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > >
> > > Simplify the implementation of metadata handling in the CameraDevice
> > > class by using the new CameraMetadata helper class.
> > >
> > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > ---
> > >  src/android/camera_device.cpp | 507 +++++++++++++---------------------
> > >  src/android/camera_device.h   |  15 +-
> > >  2 files changed, 198 insertions(+), 324 deletions(-)
> > >
> > > diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
> > > index 5f8d19b9ef3d..475fa2404421 100644
> > > --- a/src/android/camera_device.cpp
> > > +++ b/src/android/camera_device.cpp
> > > @@ -7,10 +7,10 @@
> > >
> > >  #include "camera_device.h"
> > >
> > > -#include <system/camera_metadata.h>
> > > -
> > >  #include "log.h"
> > > +#include "utils.h"
> > >
> > > +#include "camera_metadata.h"
> > >  #include "thread_rpc.h"
> > >
> > >  using namespace libcamera;
> > > @@ -59,12 +59,10 @@ CameraDevice::CameraDevice(unsigned int id, const std::shared_ptr<Camera> &camer
> > >  CameraDevice::~CameraDevice()
> > >  {
> > >  	if (staticMetadata_)
> > > -		free_camera_metadata(staticMetadata_);
> > > -	staticMetadata_ = nullptr;
> > > +		delete staticMetadata_;
> > >
> > >  	if (requestTemplate_)
> > > -		free_camera_metadata(requestTemplate_);
> > > -	requestTemplate_ = nullptr;
> > > +		delete requestTemplate_;
> > >  }
> > >
> > >  /*
> > > @@ -117,10 +115,8 @@ void CameraDevice::setCallbacks(const camera3_callback_ops_t *callbacks)
> > >   */
> > >  camera_metadata_t *CameraDevice::getStaticMetadata()
> > >  {
> > > -	int ret;
> > > -
> > >  	if (staticMetadata_)
> > > -		return staticMetadata_;
> > > +		return staticMetadata_->get();
> > >
> > >  	/*
> > >  	 * The here reported metadata are enough to implement a basic capture
> > > @@ -132,16 +128,21 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> > >  	 * \todo Keep this in sync with the actual number of entries.
> > >  	 * Currently: 46 entries, 390 bytes
> > >  	 */
> > > -	staticMetadata_ = allocate_camera_metadata(50, 500);
> > > +	staticMetadata_ = new CameraMetadata(50, 500);
> > > +	if (!staticMetadata_->isValid()) {
> > > +		LOG(HAL, Error) << "Failed to allocate static metadata";
> > > +		delete staticMetadata_;
> > > +		staticMetadata_ = nullptr;
> > > +		return nullptr;
> >
> > Empty line before return?
>
> I don't mind either way, but I haven't added one as the delete,
> assignment to nullptr and return nullptr are logically grouped in my
> opinion. Feel free to add a blank line if you prefer.
>

Ok, if this was intentional let's keep it the way it is.

> > > +	}
> > >
> > >  	/* Color correction static metadata. */
> > >  	std::vector<uint8_t> aberrationModes = {
> > >  		ANDROID_COLOR_CORRECTION_ABERRATION_MODE_OFF,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES,
> > > -			aberrationModes.data(), aberrationModes.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES,
> > > +				  aberrationModes.data(),
> > > +				  aberrationModes.size());
> > >
> > >  	/* Control static metadata. */
> > >  	std::vector<uint8_t> aeAvailableAntiBandingModes = {
> > > @@ -150,294 +151,228 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> > >  		ANDROID_CONTROL_AE_ANTIBANDING_MODE_60HZ,
> > >  		ANDROID_CONTROL_AE_ANTIBANDING_MODE_AUTO,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES,
> > > -			aeAvailableAntiBandingModes.data(),
> > > -			aeAvailableAntiBandingModes.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES,
> > > +				  aeAvailableAntiBandingModes.data(),
> > > +				  aeAvailableAntiBandingModes.size());
> > >
> > >  	std::vector<uint8_t> aeAvailableModes = {
> > >  		ANDROID_CONTROL_AE_MODE_ON,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_CONTROL_AE_AVAILABLE_MODES,
> > > -			aeAvailableModes.data(), aeAvailableModes.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_MODES,
> > > +				  aeAvailableModes.data(),
> > > +				  aeAvailableModes.size());
> > >
> > >  	std::vector<int32_t> availableAeFpsTarget = {
> > >  		15, 30,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES,
> > > -			availableAeFpsTarget.data(),
> > > -			availableAeFpsTarget.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES,
> > > +				  availableAeFpsTarget.data(),
> > > +				  availableAeFpsTarget.size());
> > >
> > >  	std::vector<int32_t> aeCompensationRange = {
> > >  		0, 0,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_CONTROL_AE_COMPENSATION_RANGE,
> > > -			aeCompensationRange.data(),
> > > -			aeCompensationRange.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_COMPENSATION_RANGE,
> > > +				  aeCompensationRange.data(),
> > > +				  aeCompensationRange.size());
> > >
> > >  	const camera_metadata_rational_t aeCompensationStep[] = {
> > >  		{ 0, 1 }
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_CONTROL_AE_COMPENSATION_STEP,
> > > -			aeCompensationStep, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_COMPENSATION_STEP,
> > > +				  aeCompensationStep, 1);
> > >
> > >  	std::vector<uint8_t> availableAfModes = {
> > >  		ANDROID_CONTROL_AF_MODE_OFF,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_CONTROL_AF_AVAILABLE_MODES,
> > > -			availableAfModes.data(), availableAfModes.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_CONTROL_AF_AVAILABLE_MODES,
> > > +				  availableAfModes.data(),
> > > +				  availableAfModes.size());
> > >
> > >  	std::vector<uint8_t> availableEffects = {
> > >  		ANDROID_CONTROL_EFFECT_MODE_OFF,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_CONTROL_AVAILABLE_EFFECTS,
> > > -			availableEffects.data(), availableEffects.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_EFFECTS,
> > > +				  availableEffects.data(),
> > > +				  availableEffects.size());
> > >
> > >  	std::vector<uint8_t> availableSceneModes = {
> > >  		ANDROID_CONTROL_SCENE_MODE_DISABLED,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_CONTROL_AVAILABLE_SCENE_MODES,
> > > -			availableSceneModes.data(), availableSceneModes.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_SCENE_MODES,
> > > +				  availableSceneModes.data(),
> > > +				  availableSceneModes.size());
> > >
> > >  	std::vector<uint8_t> availableStabilizationModes = {
> > >  		ANDROID_CONTROL_VIDEO_STABILIZATION_MODE_OFF,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES,
> > > -			availableStabilizationModes.data(),
> > > -			availableStabilizationModes.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES,
> > > +				  availableStabilizationModes.data(),
> > > +				  availableStabilizationModes.size());
> > >
> > >  	std::vector<uint8_t> availableAwbModes = {
> > >  		ANDROID_CONTROL_AWB_MODE_OFF,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_CONTROL_AWB_AVAILABLE_MODES,
> > > -			availableAwbModes.data(), availableAwbModes.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_CONTROL_AWB_AVAILABLE_MODES,
> > > +				  availableAwbModes.data(),
> > > +				  availableAwbModes.size());
> > >
> > >  	std::vector<int32_t> availableMaxRegions = {
> > >  		0, 0, 0,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_CONTROL_MAX_REGIONS,
> > > -			availableMaxRegions.data(), availableMaxRegions.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_CONTROL_MAX_REGIONS,
> > > +				  availableMaxRegions.data(),
> > > +				  availableMaxRegions.size());
> > >
> > >  	std::vector<uint8_t> sceneModesOverride = {
> > >  		ANDROID_CONTROL_AE_MODE_ON,
> > >  		ANDROID_CONTROL_AWB_MODE_AUTO,
> > >  		ANDROID_CONTROL_AF_MODE_AUTO,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_CONTROL_SCENE_MODE_OVERRIDES,
> > > -			sceneModesOverride.data(), sceneModesOverride.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_CONTROL_SCENE_MODE_OVERRIDES,
> > > +				  sceneModesOverride.data(),
> > > +				  sceneModesOverride.size());
> > >
> > >  	uint8_t aeLockAvailable = ANDROID_CONTROL_AE_LOCK_AVAILABLE_FALSE;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_CONTROL_AE_LOCK_AVAILABLE,
> > > -			&aeLockAvailable, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_LOCK_AVAILABLE,
> > > +				  &aeLockAvailable, 1);
> > >
> > >  	uint8_t awbLockAvailable = ANDROID_CONTROL_AWB_LOCK_AVAILABLE_FALSE;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
> > > -			&awbLockAvailable, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
> > > +				  &awbLockAvailable, 1);
> > >
> > >  	char availableControlModes = ANDROID_CONTROL_MODE_AUTO;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_CONTROL_AVAILABLE_MODES,
> > > -			&availableControlModes, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_MODES,
> > > +				  &availableControlModes, 1);
> > >
> > >  	/* JPEG static metadata. */
> > >  	std::vector<int32_t> availableThumbnailSizes = {
> > >  		0, 0,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
> > > -			availableThumbnailSizes.data(),
> > > -			availableThumbnailSizes.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
> > > +				  availableThumbnailSizes.data(),
> > > +				  availableThumbnailSizes.size());
> > >
> > >  	/* Sensor static metadata. */
> > >  	int32_t pixelArraySize[] = {
> > >  		2592, 1944,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -				ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
> > > -				&pixelArraySize, 2);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
> > > +				  &pixelArraySize, 2);
> > >
> > >  	int32_t sensorSizes[] = {
> > >  		0, 0, 2560, 1920,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -				ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
> > > -				&sensorSizes, 4);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
> > > +				  &sensorSizes, 4);
> > >
> > >  	int32_t sensitivityRange[] = {
> > >  		32, 2400,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -				ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
> > > -				&sensitivityRange, 2);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
> > > +				  &sensitivityRange, 2);
> > >
> > >  	uint16_t filterArr = ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT_GRBG;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -				ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
> > > -				&filterArr, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
> > > +				  &filterArr, 1);
> > >
> > >  	int64_t exposureTimeRange[] = {
> > >  		100000, 200000000,
> > >  	};
> >
> > I've been thinking for a while to stabilize on the use of std::vector in
> > place of arrays, so e can always use .data() and .size() and have
> > guaranteed we should only change the declaration and not the
> > parameters to the addEntry() operation.
> >
> > This might be a good time to do so. What do you think?
>
> I've thought about it, and constructing a vector is a bit costly
> compared to arrays. I'd rather used std::array<>, but that requires
> specifying the size explicitly :-S I've been thinking about overloading
> the addEntry() method, in order to be able to write
>
> 	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> 				  { 100000, 200000000 });
>
> I'm not sure if that will be possible as we need to handle different
> data types, but I think it's worth a try. Other overloaded methods
> should also be added for the arrays of a single element:
>
> 	staticMetadata_->addEntry(ANDROID_SENSOR_ORIENTATION, 0);
>
> I would prefer handling the standardisation of vector vs. array in a
> separate patch, when dealing with overloaded versions of addEntry(), as
> this patch is big enough already.
>

Agreed

> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -				ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> > > -				&exposureTimeRange, 2);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> > > +				  &exposureTimeRange, 2);
> > >
> > >  	int32_t orientation = 0;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -				ANDROID_SENSOR_ORIENTATION,
> > > -				&orientation, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_SENSOR_ORIENTATION,
> > > +				  &orientation, 1);
> >
> > Fits in 1 line
>
> I've kept it on two lines to use similar constructs through the whole
> function, but I don't mind much, so please feel free to change it if you
> prefer.
>

If it was intentional, let's keep it the way it is

> > >
> > >  	std::vector<int32_t> testPatterModes = {
> > >  		ANDROID_SENSOR_TEST_PATTERN_MODE_OFF,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -				ANDROID_SENSOR_AVAILABLE_TEST_PATTERN_MODES,
> > > -				testPatterModes.data(), testPatterModes.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_SENSOR_AVAILABLE_TEST_PATTERN_MODES,
> > > +				  testPatterModes.data(),
> > > +				  testPatterModes.size());
> > >
> > >  	std::vector<float> physicalSize = {
> > >  		2592, 1944,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -				ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
> > > -				physicalSize.data(), physicalSize.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
> > > +				  physicalSize.data(),
> > > +				  physicalSize.size());
> >
> > Fits in 1 line
> >
> > >
> > >  	uint8_t timestampSource = ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE_UNKNOWN;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE,
> > > -			&timestampSource, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE,
> > > +				  &timestampSource, 1);
> > >
> > >  	/* Statistics static metadata. */
> > >  	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
> > > -			&faceDetectMode, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
> > > +				  &faceDetectMode, 1);
> > >
> > >  	int32_t maxFaceCount = 0;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
> > > -			&maxFaceCount, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
> > > +				  &maxFaceCount, 1);
> > >
> > >  	/* Sync static metadata. */
> > >  	int32_t maxLatency = ANDROID_SYNC_MAX_LATENCY_UNKNOWN;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_SYNC_MAX_LATENCY, &maxLatency, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_SYNC_MAX_LATENCY, &maxLatency, 1);
> > >
> > >  	/* Flash static metadata. */
> > >  	char flashAvailable = ANDROID_FLASH_INFO_AVAILABLE_FALSE;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_FLASH_INFO_AVAILABLE,
> > > -			&flashAvailable, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_FLASH_INFO_AVAILABLE,
> > > +				  &flashAvailable, 1);
> > >
> > >  	/* Lens static metadata. */
> > >  	std::vector<float> lensApertures = {
> > >  		2.53 / 100,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -				ANDROID_LENS_INFO_AVAILABLE_APERTURES,
> > > -				lensApertures.data(), lensApertures.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_APERTURES,
> > > +				  lensApertures.data(),
> > > +				  lensApertures.size());
> > >
> > >  	uint8_t lensFacing = ANDROID_LENS_FACING_FRONT;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -				ANDROID_LENS_FACING, &lensFacing, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_LENS_FACING, &lensFacing, 1);
> > >
> > >  	std::vector<float> lensFocalLenghts = {
> > >  		1,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -				ANDROID_LENS_INFO_AVAILABLE_FOCAL_LENGTHS,
> > > -				lensFocalLenghts.data(),
> > > -				lensFocalLenghts.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_FOCAL_LENGTHS,
> > > +				  lensFocalLenghts.data(),
> > > +				  lensFocalLenghts.size());
> > >
> > >  	std::vector<uint8_t> opticalStabilizations = {
> > >  		ANDROID_LENS_OPTICAL_STABILIZATION_MODE_OFF,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -				ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
> > > -				opticalStabilizations.data(),
> > > -				opticalStabilizations.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
> > > +				  opticalStabilizations.data(),
> > > +				  opticalStabilizations.size());
> > >
> > >  	float hypeFocalDistance = 0;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -				ANDROID_LENS_INFO_HYPERFOCAL_DISTANCE,
> > > -				&hypeFocalDistance, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_LENS_INFO_HYPERFOCAL_DISTANCE,
> > > +				  &hypeFocalDistance, 1);
> > >
> > >  	float minFocusDistance = 0;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -				ANDROID_LENS_INFO_MINIMUM_FOCUS_DISTANCE,
> > > -				&minFocusDistance, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_LENS_INFO_MINIMUM_FOCUS_DISTANCE,
> > > +				  &minFocusDistance, 1);
> > >
> > >  	/* Noise reduction modes. */
> > >  	uint8_t noiseReductionModes = ANDROID_NOISE_REDUCTION_MODE_OFF;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -				ANDROID_NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES,
> > > -				&noiseReductionModes, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES,
> > > +				  &noiseReductionModes, 1);
> > >
> > >  	/* Scaler static metadata. */
> > >  	float maxDigitalZoom = 1;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_SCALER_AVAILABLE_MAX_DIGITAL_ZOOM,
> > > -			&maxDigitalZoom, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_MAX_DIGITAL_ZOOM,
> > > +				  &maxDigitalZoom, 1);
> > >
> > >  	std::vector<uint32_t> availableStreamFormats = {
> > >  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB,
> > >  		ANDROID_SCALER_AVAILABLE_FORMATS_YCbCr_420_888,
> > >  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_SCALER_AVAILABLE_FORMATS,
> > > -			availableStreamFormats.data(),
> > > -			availableStreamFormats.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_FORMATS,
> > > +				  availableStreamFormats.data(),
> > > +				  availableStreamFormats.size());
> > >
> > >  	std::vector<uint32_t> availableStreamConfigurations = {
> > >  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920,
> > > @@ -447,65 +382,57 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> > >  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED, 2560, 1920,
> > >  		ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS_OUTPUT,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS,
> > > -			availableStreamConfigurations.data(),
> > > -			availableStreamConfigurations.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS,
> > > +				  availableStreamConfigurations.data(),
> > > +				  availableStreamConfigurations.size());
> > >
> > >  	std::vector<int64_t> availableStallDurations = {
> > >  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920, 33333333,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_SCALER_AVAILABLE_STALL_DURATIONS,
> > > -			availableStallDurations.data(),
> > > -			availableStallDurations.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_STALL_DURATIONS,
> > > +				  availableStallDurations.data(),
> > > +				  availableStallDurations.size());
> > >
> > >  	std::vector<int64_t> minFrameDurations = {
> > >  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920, 33333333,
> > >  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED, 2560, 1920, 33333333,
> > >  		ANDROID_SCALER_AVAILABLE_FORMATS_YCbCr_420_888, 2560, 1920, 33333333,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_SCALER_AVAILABLE_MIN_FRAME_DURATIONS,
> > > -			minFrameDurations.data(), minFrameDurations.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_MIN_FRAME_DURATIONS,
> > > +				  minFrameDurations.data(),
> > > +				  minFrameDurations.size());
> > >
> > >  	uint8_t croppingType = ANDROID_SCALER_CROPPING_TYPE_CENTER_ONLY;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_SCALER_CROPPING_TYPE, &croppingType, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_SCALER_CROPPING_TYPE, &croppingType, 1);
> > >
> > >  	/* Info static metadata. */
> > >  	uint8_t supportedHWLevel = ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL,
> > > -			&supportedHWLevel, 1);
> > > +	staticMetadata_->addEntry(ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL,
> > > +				  &supportedHWLevel, 1);
> > >
> > >  	/* Request static metadata. */
> > >  	int32_t partialResultCount = 1;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_REQUEST_PARTIAL_RESULT_COUNT,
> > > -			&partialResultCount, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_REQUEST_PARTIAL_RESULT_COUNT,
> > > +				  &partialResultCount, 1);
> > >
> > >  	uint8_t maxPipelineDepth = 2;
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_REQUEST_PIPELINE_MAX_DEPTH,
> > > -			&maxPipelineDepth, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_REQUEST_PIPELINE_MAX_DEPTH,
> > > +				  &maxPipelineDepth, 1);
> > >
> > >  	std::vector<uint8_t> availableCapabilities = {
> > >  		ANDROID_REQUEST_AVAILABLE_CAPABILITIES_BACKWARD_COMPATIBLE,
> > >  	};
> > > -	ret = add_camera_metadata_entry(staticMetadata_,
> > > -			ANDROID_REQUEST_AVAILABLE_CAPABILITIES,
> > > -			availableCapabilities.data(),
> > > -			availableCapabilities.size());
> > > -	METADATA_ASSERT(ret);
> > > +	staticMetadata_->addEntry(ANDROID_REQUEST_AVAILABLE_CAPABILITIES,
> > > +				  availableCapabilities.data(),
> > > +				  availableCapabilities.size());
> > > +
> > > +	if (!staticMetadata_->isValid()) {
> > > +		delete staticMetadata_;
> > > +		staticMetadata_ = nullptr;
> > > +		return nullptr;
> > > +	}
> > >
> > > -	return staticMetadata_;
> > > +	return staticMetadata_->get();
> > >  }
> > >
> > >  /*
> > > @@ -513,8 +440,6 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> > >   */
> > >  const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
> > >  {
> > > -	int ret;
> > > -
> > >  	/*
> > >  	 * \todo Inspect type and pick the right metadata pack.
> > >  	 * As of now just use a single one for all templates.
> > > @@ -545,89 +470,73 @@ const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
> > >  	}
> > >
> > >  	if (requestTemplate_)
> > > -		return requestTemplate_;
> > > +		return requestTemplate_->get();
> > >
> > >  	/*
> > >  	 * \todo Keep this in sync with the actual number of entries.
> > >  	 * Currently: 12 entries, 15 bytes
> > >  	 */
> > > -	requestTemplate_ = allocate_camera_metadata(15, 20);
> > > +	requestTemplate_ = new CameraMetadata(15, 20);
> > >  	if (!requestTemplate_) {
> > >  		LOG(HAL, Error) << "Failed to allocate template metadata";
> > > +		delete requestTemplate_;
> > > +		requestTemplate_ = nullptr;
> >
> > Empty line before return ?
> >
> > >  		return nullptr;
> > >  	}
> > >
> > >  	uint8_t aeMode = ANDROID_CONTROL_AE_MODE_ON;
> > > -	ret = add_camera_metadata_entry(requestTemplate_,
> > > -			ANDROID_CONTROL_AE_MODE,
> > > -			&aeMode, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_MODE,
> > > +				   &aeMode, 1);
> >
> > This and many others entries here and below fit in 1 line.
> >
> > >
> > >  	int32_t aeExposureCompensation = 0;
> > > -	ret = add_camera_metadata_entry(requestTemplate_,
> > > -			ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION,
> > > -			&aeExposureCompensation, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION,
> > > +				   &aeExposureCompensation, 1);
> > >
> > >  	uint8_t aePrecaptureTrigger = ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER_IDLE;
> > > -	ret = add_camera_metadata_entry(requestTemplate_,
> > > -			ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER,
> > > -			&aePrecaptureTrigger, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER,
> > > +				   &aePrecaptureTrigger, 1);
> > >
> > >  	uint8_t aeLock = ANDROID_CONTROL_AE_LOCK_OFF;
> > > -	ret = add_camera_metadata_entry(requestTemplate_,
> > > -			ANDROID_CONTROL_AE_LOCK,
> > > -			&aeLock, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_LOCK,
> > > +				   &aeLock, 1);
> > >
> > >  	uint8_t afTrigger = ANDROID_CONTROL_AF_TRIGGER_IDLE;
> > > -	ret = add_camera_metadata_entry(requestTemplate_,
> > > -			ANDROID_CONTROL_AF_TRIGGER,
> > > -			&afTrigger, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	requestTemplate_->addEntry(ANDROID_CONTROL_AF_TRIGGER,
> > > +				   &afTrigger, 1);
> > >
> > >  	uint8_t awbMode = ANDROID_CONTROL_AWB_MODE_AUTO;
> > > -	ret = add_camera_metadata_entry(requestTemplate_,
> > > -			ANDROID_CONTROL_AWB_MODE,
> > > -			&awbMode, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	requestTemplate_->addEntry(ANDROID_CONTROL_AWB_MODE,
> > > +				   &awbMode, 1);
> > >
> > >  	uint8_t awbLock = ANDROID_CONTROL_AWB_LOCK_OFF;
> > > -	ret = add_camera_metadata_entry(requestTemplate_,
> > > -			ANDROID_CONTROL_AWB_LOCK,
> > > -			&awbLock, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	requestTemplate_->addEntry(ANDROID_CONTROL_AWB_LOCK,
> > > +				   &awbLock, 1);
> > >
> > >  	uint8_t flashMode = ANDROID_FLASH_MODE_OFF;
> > > -	ret = add_camera_metadata_entry(requestTemplate_,
> > > -			ANDROID_FLASH_MODE,
> > > -			&flashMode, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	requestTemplate_->addEntry(ANDROID_FLASH_MODE,
> > > +				   &flashMode, 1);
> > >
> > >  	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
> > > -	ret = add_camera_metadata_entry(requestTemplate_,
> > > -			ANDROID_STATISTICS_FACE_DETECT_MODE,
> > > -			&faceDetectMode, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	requestTemplate_->addEntry(ANDROID_STATISTICS_FACE_DETECT_MODE,
> > > +				   &faceDetectMode, 1);
> > >
> > >  	uint8_t noiseReduction = ANDROID_NOISE_REDUCTION_MODE_OFF;
> > > -	ret = add_camera_metadata_entry(requestTemplate_,
> > > -			ANDROID_NOISE_REDUCTION_MODE, &noiseReduction, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	requestTemplate_->addEntry(ANDROID_NOISE_REDUCTION_MODE,
> > > +				   &noiseReduction, 1);
> > >
> > >  	uint8_t aberrationMode = ANDROID_COLOR_CORRECTION_ABERRATION_MODE_OFF;
> > > -	ret = add_camera_metadata_entry(requestTemplate_,
> > > -			ANDROID_COLOR_CORRECTION_ABERRATION_MODE,
> > > -			&aberrationMode, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	requestTemplate_->addEntry(ANDROID_COLOR_CORRECTION_ABERRATION_MODE,
> > > +				   &aberrationMode, 1);
> > > +
> > > +	requestTemplate_->addEntry(ANDROID_CONTROL_CAPTURE_INTENT,
> > > +				   &captureIntent, 1);
> > >
> > > -	ret = add_camera_metadata_entry(requestTemplate_,
> > > -			ANDROID_CONTROL_CAPTURE_INTENT,
> > > -			&captureIntent, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	if (!requestTemplate_->isValid()) {
> > > +		delete requestTemplate_;
> > > +		requestTemplate_ = nullptr;
> >
> > You should return nullptr here, otherwise the below requestTemplate_->get();
> > will de-reference a nullptr.
>
> Absolutely, my bad.
>
> > > +	}
> > >
> > > -	return requestTemplate_;
> > > +	return requestTemplate_->get();
> > >  }
> > >
> > >  /*
> > > @@ -799,7 +708,7 @@ void CameraDevice::requestComplete(Request *request,
> > >  {
> > >  	Buffer *libcameraBuffer = buffers.begin()->second;
> > >  	camera3_buffer_status status = CAMERA3_BUFFER_STATUS_OK;
> > > -	camera_metadata_t *resultMetadata = nullptr;
> > > +	std::unique_ptr<CameraMetadata> resultMetadata;
> > >
> > >  	if (request->status() != Request::RequestComplete) {
> > >  		LOG(HAL, Error) << "Request not succesfully completed: "
> > > @@ -837,16 +746,12 @@ void CameraDevice::requestComplete(Request *request,
> > >  		captureResult.partial_result = 1;
> > >  		resultMetadata = getResultMetadata(descriptor->frameNumber,
> > >  						   libcameraBuffer->timestamp());
> > > -		captureResult.result = resultMetadata;
> > > +		captureResult.result = resultMetadata->get();
> > >  	}
> > >
> > >  	callbacks_->process_capture_result(callbacks_, &captureResult);
> > >
> > >  	delete descriptor;
> > > -	if (resultMetadata)
> > > -		free_camera_metadata(resultMetadata);
> > > -
> > > -	return;
> > >  }
> > >
> > >  void CameraDevice::notifyShutter(uint32_t frameNumber, uint64_t timestamp)
> > > @@ -875,89 +780,63 @@ void CameraDevice::notifyError(uint32_t frameNumber, camera3_stream_t *stream)
> > >  /*
> > >   * Produce a set of fixed result metadata.
> > >   */
> > > -camera_metadata_t *CameraDevice::getResultMetadata(int frame_number,
> > > -						   int64_t timestamp)
> > > +std::unique_ptr<CameraMetadata> CameraDevice::getResultMetadata(int frame_number,
> >
> > Not a fan of smart pointers, you know already. How does this work?
> > Because the compiler applies copy-elision or because of the move
> > semantic applied on the return value?
>
> std::unique_ptr<> has an operator= that takes an rvalue reference to
> another std::unique_ptr<>, and uses move semantic. As explained in
> https://en.cppreference.com/w/cpp/language/value_category, an rvalue is
> either a prvalue or an xvalue, and a prvalue can be "a function call or
> an overloaded operator expression, whose return type is non-reference".
> As far as I can tell, that's why we don't need an std::move() in the
> caller.
>

I see.. This seems to suggest both RVO and move semantic can play a
role https://stackoverflow.com/a/46571941

Ah, c++

> > difficult to follow in my opinion.
>
> I think we should standardise as much as possible on std::unique_ptr<>
> when passing ownership of a returned pointer. That's documented in
> Documentation/coding-style.rst.
>

Ack, let's keep it the way it is then.

> > > +								int64_t timestamp)
> > >  {
> > > -	int ret;
> > > -
> > >  	/*
> > >  	 * \todo Keep this in sync with the actual number of entries.
> > >  	 * Currently: 13 entries, 36 bytes
> > >  	 */
> > > -	camera_metadata_t *resultMetadata = allocate_camera_metadata(15, 50);
> > > +	std::unique_ptr<CameraMetadata> resultMetadata =
> > > +		utils::make_unique<CameraMetadata>(15, 50);
> > > +	if (!resultMetadata->isValid()) {
> > > +		LOG(HAL, Error) << "Failed to allocate static metadata";
> > > +		return nullptr;
> > > +	}
> > >
> > >  	const uint8_t ae_state = ANDROID_CONTROL_AE_STATE_CONVERGED;
> > > -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AE_STATE,
> > > -					&ae_state, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	resultMetadata->addEntry(ANDROID_CONTROL_AE_STATE, &ae_state, 1);
> > >
> > >  	const uint8_t ae_lock = ANDROID_CONTROL_AE_LOCK_OFF;
> > > -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AE_LOCK,
> > > -					&ae_lock, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	resultMetadata->addEntry(ANDROID_CONTROL_AE_LOCK, &ae_lock, 1);
> > >
> > >  	uint8_t af_state = ANDROID_CONTROL_AF_STATE_INACTIVE;
> > > -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AF_STATE,
> > > -					&af_state, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	resultMetadata->addEntry(ANDROID_CONTROL_AF_STATE, &af_state, 1);
> > >
> > >  	const uint8_t awb_state = ANDROID_CONTROL_AWB_STATE_CONVERGED;
> > > -	ret = add_camera_metadata_entry(resultMetadata,
> > > -					ANDROID_CONTROL_AWB_STATE,
> > > -					&awb_state, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	resultMetadata->addEntry(ANDROID_CONTROL_AWB_STATE, &awb_state, 1);
> > >
> > >  	const uint8_t awb_lock = ANDROID_CONTROL_AWB_LOCK_OFF;
> > > -	ret = add_camera_metadata_entry(resultMetadata,
> > > -					ANDROID_CONTROL_AWB_LOCK,
> > > -					&awb_lock, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	resultMetadata->addEntry(ANDROID_CONTROL_AWB_LOCK, &awb_lock, 1);
> > >
> > >  	const uint8_t lens_state = ANDROID_LENS_STATE_STATIONARY;
> > > -	ret = add_camera_metadata_entry(resultMetadata,
> > > -					ANDROID_LENS_STATE,
> > > -					&lens_state, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	resultMetadata->addEntry(ANDROID_LENS_STATE, &lens_state, 1);
> > >
> > >  	int32_t sensorSizes[] = {
> > >  		0, 0, 2560, 1920,
> > >  	};
> > > -	ret = add_camera_metadata_entry(resultMetadata,
> > > -					ANDROID_SCALER_CROP_REGION,
> > > -					sensorSizes, 4);
> > > -	METADATA_ASSERT(ret);
> > > +	resultMetadata->addEntry(ANDROID_SCALER_CROP_REGION, sensorSizes, 4);
> > >
> > > -	ret = add_camera_metadata_entry(resultMetadata,
> > > -					ANDROID_SENSOR_TIMESTAMP,
> > > -					&timestamp, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	resultMetadata->addEntry(ANDROID_SENSOR_TIMESTAMP, &timestamp, 1);
> > >
> > >  	/* 33.3 msec */
> > >  	const int64_t rolling_shutter_skew = 33300000;
> > > -	ret = add_camera_metadata_entry(resultMetadata,
> > > -					ANDROID_SENSOR_ROLLING_SHUTTER_SKEW,
> > > -					&rolling_shutter_skew, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	resultMetadata->addEntry(ANDROID_SENSOR_ROLLING_SHUTTER_SKEW,
> > > +				 &rolling_shutter_skew, 1);
> > >
> > >  	/* 16.6 msec */
> > >  	const int64_t exposure_time = 16600000;
> > > -	ret = add_camera_metadata_entry(resultMetadata,
> > > -					ANDROID_SENSOR_EXPOSURE_TIME,
> > > -					&exposure_time, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	resultMetadata->addEntry(ANDROID_SENSOR_EXPOSURE_TIME,
> > > +				 &exposure_time, 1);
> > >
> > >  	const uint8_t lens_shading_map_mode =
> > >  				ANDROID_STATISTICS_LENS_SHADING_MAP_MODE_OFF;
> > > -	ret = add_camera_metadata_entry(resultMetadata,
> > > -					ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
> > > -					&lens_shading_map_mode, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	resultMetadata->addEntry(ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
> > > +				 &lens_shading_map_mode, 1);
> > >
> > >  	const uint8_t scene_flicker = ANDROID_STATISTICS_SCENE_FLICKER_NONE;
> > > -	ret = add_camera_metadata_entry(resultMetadata,
> > > -					ANDROID_STATISTICS_SCENE_FLICKER,
> > > -					&scene_flicker, 1);
> > > -	METADATA_ASSERT(ret);
> > > +	resultMetadata->addEntry(ANDROID_STATISTICS_SCENE_FLICKER,
> > > +				 &scene_flicker, 1);
> >
> > Shouldn't you check if the metadata pack is valid ?
>
> Good point. Should we check here or in the caller ? As the caller would
> then need a nullptr check I'm tempted to do so in the caller. Actually,
> without a change to the code, the caller will operate correctly I
> believe
>
>                 resultMetadata = getResultMetadata(descriptor->frameNumber,
>                                                    libcameraBuffer->timestamp());
>                 captureResult.result = resultMetadata->get();
>
> which will set captureResult.result to nullptr if resultMetadata is not
> valid.

Yeah, but in that case we should notify an error back to the stack.

What about:

        resultMetadata = getResultMetadata(descriptor->frameNumber,
                                           libcameraBuffer->timestamp());
	if (status == CAMERA3_BUFFER_STATUS_ERROR || !resultMetadata) {
		/* \todo Improve error handling. */
		notifyError(descriptor->frameNumber,
			    descriptor->buffers[0].stream);
	} else {
		notifyShutter(descriptor->frameNumber,
			      libcameraBuffer->timestamp());

		captureResult.partial_result = 1;
		captureResult.result = resultMetadata->get();
	}

The drawback is that we're generating the result metadata even if
status is set to CAMERA3_BUFFER_STATUS_ERROR.

Thanks
   j

> > >
> > >  	return resultMetadata;
> > >  }
> > > diff --git a/src/android/camera_device.h b/src/android/camera_device.h
> > > index 7897ba9dc5c7..65ba877a02ea 100644
> > > --- a/src/android/camera_device.h
> > > +++ b/src/android/camera_device.h
> > > @@ -19,13 +19,7 @@
> > >
> > >  #include "message.h"
> > >
> > > -#define METADATA_ASSERT(_r)		\
> > > -	do {				\
> > > -		if (!(_r)) break;	\
> > > -		LOG(HAL, Error) << "Error: " << __func__ << ":" << __LINE__; \
> > > -		return nullptr;		\
> > > -	} while(0);
> > > -
> > > +class CameraMetadata;
> > >  class ThreadRpc;
> > >
> > >  class CameraDevice : public libcamera::Object
> > > @@ -59,14 +53,15 @@ private:
> > >
> > >  	void notifyShutter(uint32_t frameNumber, uint64_t timestamp);
> > >  	void notifyError(uint32_t frameNumber, camera3_stream_t *stream);
> > > -	camera_metadata_t *getResultMetadata(int frame_number, int64_t timestamp);
> > > +	std::unique_ptr<CameraMetadata> getResultMetadata(int frame_number,
> > > +							  int64_t timestamp);
> > >
> > >  	bool running_;
> > >  	std::shared_ptr<libcamera::Camera> camera_;
> > >  	std::unique_ptr<libcamera::CameraConfiguration> config_;
> > >
> > > -	camera_metadata_t *staticMetadata_;
> > > -	camera_metadata_t *requestTemplate_;
> > > +	CameraMetadata *staticMetadata_;
> > > +	CameraMetadata *requestTemplate_;
> > >  	const camera3_callback_ops_t *callbacks_;
> > >  };
> > >
>
> --
> Regards,
>
> Laurent Pinchart
Laurent Pinchart Sept. 5, 2019, 10:02 a.m. UTC | #4
Hi Jacopo,

Thank you for the patch.

On Thu, Sep 05, 2019 at 11:52:05AM +0200, Jacopo Mondi wrote:
> On Thu, Sep 05, 2019 at 12:36:57PM +0300, Laurent Pinchart wrote:
> > On Thu, Sep 05, 2019 at 10:18:28AM +0200, Jacopo Mondi wrote:
> >> On Thu, Sep 05, 2019 at 09:47:34AM +0200, Jacopo Mondi wrote:
> >>> From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >>>
> >>> Simplify the implementation of metadata handling in the CameraDevice
> >>> class by using the new CameraMetadata helper class.
> >>>
> >>> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >>> ---
> >>>  src/android/camera_device.cpp | 507 +++++++++++++---------------------
> >>>  src/android/camera_device.h   |  15 +-
> >>>  2 files changed, 198 insertions(+), 324 deletions(-)
> >>>
> >>> diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
> >>> index 5f8d19b9ef3d..475fa2404421 100644
> >>> --- a/src/android/camera_device.cpp
> >>> +++ b/src/android/camera_device.cpp
> >>> @@ -7,10 +7,10 @@
> >>>
> >>>  #include "camera_device.h"
> >>>
> >>> -#include <system/camera_metadata.h>
> >>> -
> >>>  #include "log.h"
> >>> +#include "utils.h"
> >>>
> >>> +#include "camera_metadata.h"
> >>>  #include "thread_rpc.h"
> >>>
> >>>  using namespace libcamera;
> >>> @@ -59,12 +59,10 @@ CameraDevice::CameraDevice(unsigned int id, const std::shared_ptr<Camera> &camer
> >>>  CameraDevice::~CameraDevice()
> >>>  {
> >>>  	if (staticMetadata_)
> >>> -		free_camera_metadata(staticMetadata_);
> >>> -	staticMetadata_ = nullptr;
> >>> +		delete staticMetadata_;
> >>>
> >>>  	if (requestTemplate_)
> >>> -		free_camera_metadata(requestTemplate_);
> >>> -	requestTemplate_ = nullptr;
> >>> +		delete requestTemplate_;
> >>>  }
> >>>
> >>>  /*
> >>> @@ -117,10 +115,8 @@ void CameraDevice::setCallbacks(const camera3_callback_ops_t *callbacks)
> >>>   */
> >>>  camera_metadata_t *CameraDevice::getStaticMetadata()
> >>>  {
> >>> -	int ret;
> >>> -
> >>>  	if (staticMetadata_)
> >>> -		return staticMetadata_;
> >>> +		return staticMetadata_->get();
> >>>
> >>>  	/*
> >>>  	 * The here reported metadata are enough to implement a basic capture
> >>> @@ -132,16 +128,21 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> >>>  	 * \todo Keep this in sync with the actual number of entries.
> >>>  	 * Currently: 46 entries, 390 bytes
> >>>  	 */
> >>> -	staticMetadata_ = allocate_camera_metadata(50, 500);
> >>> +	staticMetadata_ = new CameraMetadata(50, 500);
> >>> +	if (!staticMetadata_->isValid()) {
> >>> +		LOG(HAL, Error) << "Failed to allocate static metadata";
> >>> +		delete staticMetadata_;
> >>> +		staticMetadata_ = nullptr;
> >>> +		return nullptr;
> >>
> >> Empty line before return?
> >
> > I don't mind either way, but I haven't added one as the delete,
> > assignment to nullptr and return nullptr are logically grouped in my
> > opinion. Feel free to add a blank line if you prefer.
> 
> Ok, if this was intentional let's keep it the way it is.
> 
> >>> +	}
> >>>
> >>>  	/* Color correction static metadata. */
> >>>  	std::vector<uint8_t> aberrationModes = {
> >>>  		ANDROID_COLOR_CORRECTION_ABERRATION_MODE_OFF,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES,
> >>> -			aberrationModes.data(), aberrationModes.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES,
> >>> +				  aberrationModes.data(),
> >>> +				  aberrationModes.size());
> >>>
> >>>  	/* Control static metadata. */
> >>>  	std::vector<uint8_t> aeAvailableAntiBandingModes = {
> >>> @@ -150,294 +151,228 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> >>>  		ANDROID_CONTROL_AE_ANTIBANDING_MODE_60HZ,
> >>>  		ANDROID_CONTROL_AE_ANTIBANDING_MODE_AUTO,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES,
> >>> -			aeAvailableAntiBandingModes.data(),
> >>> -			aeAvailableAntiBandingModes.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES,
> >>> +				  aeAvailableAntiBandingModes.data(),
> >>> +				  aeAvailableAntiBandingModes.size());
> >>>
> >>>  	std::vector<uint8_t> aeAvailableModes = {
> >>>  		ANDROID_CONTROL_AE_MODE_ON,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_CONTROL_AE_AVAILABLE_MODES,
> >>> -			aeAvailableModes.data(), aeAvailableModes.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_MODES,
> >>> +				  aeAvailableModes.data(),
> >>> +				  aeAvailableModes.size());
> >>>
> >>>  	std::vector<int32_t> availableAeFpsTarget = {
> >>>  		15, 30,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES,
> >>> -			availableAeFpsTarget.data(),
> >>> -			availableAeFpsTarget.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES,
> >>> +				  availableAeFpsTarget.data(),
> >>> +				  availableAeFpsTarget.size());
> >>>
> >>>  	std::vector<int32_t> aeCompensationRange = {
> >>>  		0, 0,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_CONTROL_AE_COMPENSATION_RANGE,
> >>> -			aeCompensationRange.data(),
> >>> -			aeCompensationRange.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_COMPENSATION_RANGE,
> >>> +				  aeCompensationRange.data(),
> >>> +				  aeCompensationRange.size());
> >>>
> >>>  	const camera_metadata_rational_t aeCompensationStep[] = {
> >>>  		{ 0, 1 }
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_CONTROL_AE_COMPENSATION_STEP,
> >>> -			aeCompensationStep, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_COMPENSATION_STEP,
> >>> +				  aeCompensationStep, 1);
> >>>
> >>>  	std::vector<uint8_t> availableAfModes = {
> >>>  		ANDROID_CONTROL_AF_MODE_OFF,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_CONTROL_AF_AVAILABLE_MODES,
> >>> -			availableAfModes.data(), availableAfModes.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AF_AVAILABLE_MODES,
> >>> +				  availableAfModes.data(),
> >>> +				  availableAfModes.size());
> >>>
> >>>  	std::vector<uint8_t> availableEffects = {
> >>>  		ANDROID_CONTROL_EFFECT_MODE_OFF,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_CONTROL_AVAILABLE_EFFECTS,
> >>> -			availableEffects.data(), availableEffects.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_EFFECTS,
> >>> +				  availableEffects.data(),
> >>> +				  availableEffects.size());
> >>>
> >>>  	std::vector<uint8_t> availableSceneModes = {
> >>>  		ANDROID_CONTROL_SCENE_MODE_DISABLED,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_CONTROL_AVAILABLE_SCENE_MODES,
> >>> -			availableSceneModes.data(), availableSceneModes.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_SCENE_MODES,
> >>> +				  availableSceneModes.data(),
> >>> +				  availableSceneModes.size());
> >>>
> >>>  	std::vector<uint8_t> availableStabilizationModes = {
> >>>  		ANDROID_CONTROL_VIDEO_STABILIZATION_MODE_OFF,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES,
> >>> -			availableStabilizationModes.data(),
> >>> -			availableStabilizationModes.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES,
> >>> +				  availableStabilizationModes.data(),
> >>> +				  availableStabilizationModes.size());
> >>>
> >>>  	std::vector<uint8_t> availableAwbModes = {
> >>>  		ANDROID_CONTROL_AWB_MODE_OFF,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_CONTROL_AWB_AVAILABLE_MODES,
> >>> -			availableAwbModes.data(), availableAwbModes.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AWB_AVAILABLE_MODES,
> >>> +				  availableAwbModes.data(),
> >>> +				  availableAwbModes.size());
> >>>
> >>>  	std::vector<int32_t> availableMaxRegions = {
> >>>  		0, 0, 0,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_CONTROL_MAX_REGIONS,
> >>> -			availableMaxRegions.data(), availableMaxRegions.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_MAX_REGIONS,
> >>> +				  availableMaxRegions.data(),
> >>> +				  availableMaxRegions.size());
> >>>
> >>>  	std::vector<uint8_t> sceneModesOverride = {
> >>>  		ANDROID_CONTROL_AE_MODE_ON,
> >>>  		ANDROID_CONTROL_AWB_MODE_AUTO,
> >>>  		ANDROID_CONTROL_AF_MODE_AUTO,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_CONTROL_SCENE_MODE_OVERRIDES,
> >>> -			sceneModesOverride.data(), sceneModesOverride.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_SCENE_MODE_OVERRIDES,
> >>> +				  sceneModesOverride.data(),
> >>> +				  sceneModesOverride.size());
> >>>
> >>>  	uint8_t aeLockAvailable = ANDROID_CONTROL_AE_LOCK_AVAILABLE_FALSE;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_CONTROL_AE_LOCK_AVAILABLE,
> >>> -			&aeLockAvailable, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_LOCK_AVAILABLE,
> >>> +				  &aeLockAvailable, 1);
> >>>
> >>>  	uint8_t awbLockAvailable = ANDROID_CONTROL_AWB_LOCK_AVAILABLE_FALSE;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
> >>> -			&awbLockAvailable, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
> >>> +				  &awbLockAvailable, 1);
> >>>
> >>>  	char availableControlModes = ANDROID_CONTROL_MODE_AUTO;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_CONTROL_AVAILABLE_MODES,
> >>> -			&availableControlModes, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_MODES,
> >>> +				  &availableControlModes, 1);
> >>>
> >>>  	/* JPEG static metadata. */
> >>>  	std::vector<int32_t> availableThumbnailSizes = {
> >>>  		0, 0,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
> >>> -			availableThumbnailSizes.data(),
> >>> -			availableThumbnailSizes.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
> >>> +				  availableThumbnailSizes.data(),
> >>> +				  availableThumbnailSizes.size());
> >>>
> >>>  	/* Sensor static metadata. */
> >>>  	int32_t pixelArraySize[] = {
> >>>  		2592, 1944,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -				ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
> >>> -				&pixelArraySize, 2);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
> >>> +				  &pixelArraySize, 2);
> >>>
> >>>  	int32_t sensorSizes[] = {
> >>>  		0, 0, 2560, 1920,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -				ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
> >>> -				&sensorSizes, 4);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
> >>> +				  &sensorSizes, 4);
> >>>
> >>>  	int32_t sensitivityRange[] = {
> >>>  		32, 2400,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -				ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
> >>> -				&sensitivityRange, 2);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
> >>> +				  &sensitivityRange, 2);
> >>>
> >>>  	uint16_t filterArr = ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT_GRBG;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -				ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
> >>> -				&filterArr, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
> >>> +				  &filterArr, 1);
> >>>
> >>>  	int64_t exposureTimeRange[] = {
> >>>  		100000, 200000000,
> >>>  	};
> >>
> >> I've been thinking for a while to stabilize on the use of std::vector in
> >> place of arrays, so e can always use .data() and .size() and have
> >> guaranteed we should only change the declaration and not the
> >> parameters to the addEntry() operation.
> >>
> >> This might be a good time to do so. What do you think?
> >
> > I've thought about it, and constructing a vector is a bit costly
> > compared to arrays. I'd rather used std::array<>, but that requires
> > specifying the size explicitly :-S I've been thinking about overloading
> > the addEntry() method, in order to be able to write
> >
> > 	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> > 				  { 100000, 200000000 });
> >
> > I'm not sure if that will be possible as we need to handle different
> > data types, but I think it's worth a try. Other overloaded methods
> > should also be added for the arrays of a single element:
> >
> > 	staticMetadata_->addEntry(ANDROID_SENSOR_ORIENTATION, 0);
> >
> > I would prefer handling the standardisation of vector vs. array in a
> > separate patch, when dealing with overloaded versions of addEntry(), as
> > this patch is big enough already.
> 
> Agreed
> 
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -				ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> >>> -				&exposureTimeRange, 2);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> >>> +				  &exposureTimeRange, 2);
> >>>
> >>>  	int32_t orientation = 0;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -				ANDROID_SENSOR_ORIENTATION,
> >>> -				&orientation, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_ORIENTATION,
> >>> +				  &orientation, 1);
> >>
> >> Fits in 1 line
> >
> > I've kept it on two lines to use similar constructs through the whole
> > function, but I don't mind much, so please feel free to change it if you
> > prefer.
> 
> If it was intentional, let's keep it the way it is
> 
> >>>
> >>>  	std::vector<int32_t> testPatterModes = {
> >>>  		ANDROID_SENSOR_TEST_PATTERN_MODE_OFF,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -				ANDROID_SENSOR_AVAILABLE_TEST_PATTERN_MODES,
> >>> -				testPatterModes.data(), testPatterModes.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_AVAILABLE_TEST_PATTERN_MODES,
> >>> +				  testPatterModes.data(),
> >>> +				  testPatterModes.size());
> >>>
> >>>  	std::vector<float> physicalSize = {
> >>>  		2592, 1944,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -				ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
> >>> -				physicalSize.data(), physicalSize.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
> >>> +				  physicalSize.data(),
> >>> +				  physicalSize.size());
> >>
> >> Fits in 1 line
> >>
> >>>
> >>>  	uint8_t timestampSource = ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE_UNKNOWN;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE,
> >>> -			&timestampSource, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE,
> >>> +				  &timestampSource, 1);
> >>>
> >>>  	/* Statistics static metadata. */
> >>>  	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
> >>> -			&faceDetectMode, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
> >>> +				  &faceDetectMode, 1);
> >>>
> >>>  	int32_t maxFaceCount = 0;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
> >>> -			&maxFaceCount, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
> >>> +				  &maxFaceCount, 1);
> >>>
> >>>  	/* Sync static metadata. */
> >>>  	int32_t maxLatency = ANDROID_SYNC_MAX_LATENCY_UNKNOWN;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_SYNC_MAX_LATENCY, &maxLatency, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_SYNC_MAX_LATENCY, &maxLatency, 1);
> >>>
> >>>  	/* Flash static metadata. */
> >>>  	char flashAvailable = ANDROID_FLASH_INFO_AVAILABLE_FALSE;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_FLASH_INFO_AVAILABLE,
> >>> -			&flashAvailable, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_FLASH_INFO_AVAILABLE,
> >>> +				  &flashAvailable, 1);
> >>>
> >>>  	/* Lens static metadata. */
> >>>  	std::vector<float> lensApertures = {
> >>>  		2.53 / 100,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -				ANDROID_LENS_INFO_AVAILABLE_APERTURES,
> >>> -				lensApertures.data(), lensApertures.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_APERTURES,
> >>> +				  lensApertures.data(),
> >>> +				  lensApertures.size());
> >>>
> >>>  	uint8_t lensFacing = ANDROID_LENS_FACING_FRONT;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -				ANDROID_LENS_FACING, &lensFacing, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_LENS_FACING, &lensFacing, 1);
> >>>
> >>>  	std::vector<float> lensFocalLenghts = {
> >>>  		1,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -				ANDROID_LENS_INFO_AVAILABLE_FOCAL_LENGTHS,
> >>> -				lensFocalLenghts.data(),
> >>> -				lensFocalLenghts.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_FOCAL_LENGTHS,
> >>> +				  lensFocalLenghts.data(),
> >>> +				  lensFocalLenghts.size());
> >>>
> >>>  	std::vector<uint8_t> opticalStabilizations = {
> >>>  		ANDROID_LENS_OPTICAL_STABILIZATION_MODE_OFF,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -				ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
> >>> -				opticalStabilizations.data(),
> >>> -				opticalStabilizations.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
> >>> +				  opticalStabilizations.data(),
> >>> +				  opticalStabilizations.size());
> >>>
> >>>  	float hypeFocalDistance = 0;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -				ANDROID_LENS_INFO_HYPERFOCAL_DISTANCE,
> >>> -				&hypeFocalDistance, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_HYPERFOCAL_DISTANCE,
> >>> +				  &hypeFocalDistance, 1);
> >>>
> >>>  	float minFocusDistance = 0;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -				ANDROID_LENS_INFO_MINIMUM_FOCUS_DISTANCE,
> >>> -				&minFocusDistance, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_MINIMUM_FOCUS_DISTANCE,
> >>> +				  &minFocusDistance, 1);
> >>>
> >>>  	/* Noise reduction modes. */
> >>>  	uint8_t noiseReductionModes = ANDROID_NOISE_REDUCTION_MODE_OFF;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -				ANDROID_NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES,
> >>> -				&noiseReductionModes, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES,
> >>> +				  &noiseReductionModes, 1);
> >>>
> >>>  	/* Scaler static metadata. */
> >>>  	float maxDigitalZoom = 1;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_SCALER_AVAILABLE_MAX_DIGITAL_ZOOM,
> >>> -			&maxDigitalZoom, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_MAX_DIGITAL_ZOOM,
> >>> +				  &maxDigitalZoom, 1);
> >>>
> >>>  	std::vector<uint32_t> availableStreamFormats = {
> >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB,
> >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_YCbCr_420_888,
> >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_SCALER_AVAILABLE_FORMATS,
> >>> -			availableStreamFormats.data(),
> >>> -			availableStreamFormats.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_FORMATS,
> >>> +				  availableStreamFormats.data(),
> >>> +				  availableStreamFormats.size());
> >>>
> >>>  	std::vector<uint32_t> availableStreamConfigurations = {
> >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920,
> >>> @@ -447,65 +382,57 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED, 2560, 1920,
> >>>  		ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS_OUTPUT,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS,
> >>> -			availableStreamConfigurations.data(),
> >>> -			availableStreamConfigurations.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS,
> >>> +				  availableStreamConfigurations.data(),
> >>> +				  availableStreamConfigurations.size());
> >>>
> >>>  	std::vector<int64_t> availableStallDurations = {
> >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920, 33333333,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_SCALER_AVAILABLE_STALL_DURATIONS,
> >>> -			availableStallDurations.data(),
> >>> -			availableStallDurations.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_STALL_DURATIONS,
> >>> +				  availableStallDurations.data(),
> >>> +				  availableStallDurations.size());
> >>>
> >>>  	std::vector<int64_t> minFrameDurations = {
> >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920, 33333333,
> >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED, 2560, 1920, 33333333,
> >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_YCbCr_420_888, 2560, 1920, 33333333,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_SCALER_AVAILABLE_MIN_FRAME_DURATIONS,
> >>> -			minFrameDurations.data(), minFrameDurations.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_MIN_FRAME_DURATIONS,
> >>> +				  minFrameDurations.data(),
> >>> +				  minFrameDurations.size());
> >>>
> >>>  	uint8_t croppingType = ANDROID_SCALER_CROPPING_TYPE_CENTER_ONLY;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_SCALER_CROPPING_TYPE, &croppingType, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_SCALER_CROPPING_TYPE, &croppingType, 1);
> >>>
> >>>  	/* Info static metadata. */
> >>>  	uint8_t supportedHWLevel = ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL,
> >>> -			&supportedHWLevel, 1);
> >>> +	staticMetadata_->addEntry(ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL,
> >>> +				  &supportedHWLevel, 1);
> >>>
> >>>  	/* Request static metadata. */
> >>>  	int32_t partialResultCount = 1;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_REQUEST_PARTIAL_RESULT_COUNT,
> >>> -			&partialResultCount, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_REQUEST_PARTIAL_RESULT_COUNT,
> >>> +				  &partialResultCount, 1);
> >>>
> >>>  	uint8_t maxPipelineDepth = 2;
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_REQUEST_PIPELINE_MAX_DEPTH,
> >>> -			&maxPipelineDepth, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_REQUEST_PIPELINE_MAX_DEPTH,
> >>> +				  &maxPipelineDepth, 1);
> >>>
> >>>  	std::vector<uint8_t> availableCapabilities = {
> >>>  		ANDROID_REQUEST_AVAILABLE_CAPABILITIES_BACKWARD_COMPATIBLE,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>> -			ANDROID_REQUEST_AVAILABLE_CAPABILITIES,
> >>> -			availableCapabilities.data(),
> >>> -			availableCapabilities.size());
> >>> -	METADATA_ASSERT(ret);
> >>> +	staticMetadata_->addEntry(ANDROID_REQUEST_AVAILABLE_CAPABILITIES,
> >>> +				  availableCapabilities.data(),
> >>> +				  availableCapabilities.size());
> >>> +
> >>> +	if (!staticMetadata_->isValid()) {
> >>> +		delete staticMetadata_;
> >>> +		staticMetadata_ = nullptr;
> >>> +		return nullptr;
> >>> +	}
> >>>
> >>> -	return staticMetadata_;
> >>> +	return staticMetadata_->get();
> >>>  }
> >>>
> >>>  /*
> >>> @@ -513,8 +440,6 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> >>>   */
> >>>  const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
> >>>  {
> >>> -	int ret;
> >>> -
> >>>  	/*
> >>>  	 * \todo Inspect type and pick the right metadata pack.
> >>>  	 * As of now just use a single one for all templates.
> >>> @@ -545,89 +470,73 @@ const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
> >>>  	}
> >>>
> >>>  	if (requestTemplate_)
> >>> -		return requestTemplate_;
> >>> +		return requestTemplate_->get();
> >>>
> >>>  	/*
> >>>  	 * \todo Keep this in sync with the actual number of entries.
> >>>  	 * Currently: 12 entries, 15 bytes
> >>>  	 */
> >>> -	requestTemplate_ = allocate_camera_metadata(15, 20);
> >>> +	requestTemplate_ = new CameraMetadata(15, 20);
> >>>  	if (!requestTemplate_) {
> >>>  		LOG(HAL, Error) << "Failed to allocate template metadata";
> >>> +		delete requestTemplate_;
> >>> +		requestTemplate_ = nullptr;
> >>
> >> Empty line before return ?
> >>
> >>>  		return nullptr;
> >>>  	}
> >>>
> >>>  	uint8_t aeMode = ANDROID_CONTROL_AE_MODE_ON;
> >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>> -			ANDROID_CONTROL_AE_MODE,
> >>> -			&aeMode, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_MODE,
> >>> +				   &aeMode, 1);
> >>
> >> This and many others entries here and below fit in 1 line.
> >>
> >>>
> >>>  	int32_t aeExposureCompensation = 0;
> >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>> -			ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION,
> >>> -			&aeExposureCompensation, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION,
> >>> +				   &aeExposureCompensation, 1);
> >>>
> >>>  	uint8_t aePrecaptureTrigger = ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER_IDLE;
> >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>> -			ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER,
> >>> -			&aePrecaptureTrigger, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER,
> >>> +				   &aePrecaptureTrigger, 1);
> >>>
> >>>  	uint8_t aeLock = ANDROID_CONTROL_AE_LOCK_OFF;
> >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>> -			ANDROID_CONTROL_AE_LOCK,
> >>> -			&aeLock, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_LOCK,
> >>> +				   &aeLock, 1);
> >>>
> >>>  	uint8_t afTrigger = ANDROID_CONTROL_AF_TRIGGER_IDLE;
> >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>> -			ANDROID_CONTROL_AF_TRIGGER,
> >>> -			&afTrigger, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AF_TRIGGER,
> >>> +				   &afTrigger, 1);
> >>>
> >>>  	uint8_t awbMode = ANDROID_CONTROL_AWB_MODE_AUTO;
> >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>> -			ANDROID_CONTROL_AWB_MODE,
> >>> -			&awbMode, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AWB_MODE,
> >>> +				   &awbMode, 1);
> >>>
> >>>  	uint8_t awbLock = ANDROID_CONTROL_AWB_LOCK_OFF;
> >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>> -			ANDROID_CONTROL_AWB_LOCK,
> >>> -			&awbLock, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AWB_LOCK,
> >>> +				   &awbLock, 1);
> >>>
> >>>  	uint8_t flashMode = ANDROID_FLASH_MODE_OFF;
> >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>> -			ANDROID_FLASH_MODE,
> >>> -			&flashMode, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	requestTemplate_->addEntry(ANDROID_FLASH_MODE,
> >>> +				   &flashMode, 1);
> >>>
> >>>  	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
> >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>> -			ANDROID_STATISTICS_FACE_DETECT_MODE,
> >>> -			&faceDetectMode, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	requestTemplate_->addEntry(ANDROID_STATISTICS_FACE_DETECT_MODE,
> >>> +				   &faceDetectMode, 1);
> >>>
> >>>  	uint8_t noiseReduction = ANDROID_NOISE_REDUCTION_MODE_OFF;
> >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>> -			ANDROID_NOISE_REDUCTION_MODE, &noiseReduction, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	requestTemplate_->addEntry(ANDROID_NOISE_REDUCTION_MODE,
> >>> +				   &noiseReduction, 1);
> >>>
> >>>  	uint8_t aberrationMode = ANDROID_COLOR_CORRECTION_ABERRATION_MODE_OFF;
> >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>> -			ANDROID_COLOR_CORRECTION_ABERRATION_MODE,
> >>> -			&aberrationMode, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	requestTemplate_->addEntry(ANDROID_COLOR_CORRECTION_ABERRATION_MODE,
> >>> +				   &aberrationMode, 1);
> >>> +
> >>> +	requestTemplate_->addEntry(ANDROID_CONTROL_CAPTURE_INTENT,
> >>> +				   &captureIntent, 1);
> >>>
> >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>> -			ANDROID_CONTROL_CAPTURE_INTENT,
> >>> -			&captureIntent, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	if (!requestTemplate_->isValid()) {
> >>> +		delete requestTemplate_;
> >>> +		requestTemplate_ = nullptr;
> >>
> >> You should return nullptr here, otherwise the below requestTemplate_->get();
> >> will de-reference a nullptr.
> >
> > Absolutely, my bad.
> >
> >>> +	}
> >>>
> >>> -	return requestTemplate_;
> >>> +	return requestTemplate_->get();
> >>>  }
> >>>
> >>>  /*
> >>> @@ -799,7 +708,7 @@ void CameraDevice::requestComplete(Request *request,
> >>>  {
> >>>  	Buffer *libcameraBuffer = buffers.begin()->second;
> >>>  	camera3_buffer_status status = CAMERA3_BUFFER_STATUS_OK;
> >>> -	camera_metadata_t *resultMetadata = nullptr;
> >>> +	std::unique_ptr<CameraMetadata> resultMetadata;
> >>>
> >>>  	if (request->status() != Request::RequestComplete) {
> >>>  		LOG(HAL, Error) << "Request not succesfully completed: "
> >>> @@ -837,16 +746,12 @@ void CameraDevice::requestComplete(Request *request,
> >>>  		captureResult.partial_result = 1;
> >>>  		resultMetadata = getResultMetadata(descriptor->frameNumber,
> >>>  						   libcameraBuffer->timestamp());
> >>> -		captureResult.result = resultMetadata;
> >>> +		captureResult.result = resultMetadata->get();
> >>>  	}
> >>>
> >>>  	callbacks_->process_capture_result(callbacks_, &captureResult);
> >>>
> >>>  	delete descriptor;
> >>> -	if (resultMetadata)
> >>> -		free_camera_metadata(resultMetadata);
> >>> -
> >>> -	return;
> >>>  }
> >>>
> >>>  void CameraDevice::notifyShutter(uint32_t frameNumber, uint64_t timestamp)
> >>> @@ -875,89 +780,63 @@ void CameraDevice::notifyError(uint32_t frameNumber, camera3_stream_t *stream)
> >>>  /*
> >>>   * Produce a set of fixed result metadata.
> >>>   */
> >>> -camera_metadata_t *CameraDevice::getResultMetadata(int frame_number,
> >>> -						   int64_t timestamp)
> >>> +std::unique_ptr<CameraMetadata> CameraDevice::getResultMetadata(int frame_number,
> >>
> >> Not a fan of smart pointers, you know already. How does this work?
> >> Because the compiler applies copy-elision or because of the move
> >> semantic applied on the return value?
> >
> > std::unique_ptr<> has an operator= that takes an rvalue reference to
> > another std::unique_ptr<>, and uses move semantic. As explained in
> > https://en.cppreference.com/w/cpp/language/value_category, an rvalue is
> > either a prvalue or an xvalue, and a prvalue can be "a function call or
> > an overloaded operator expression, whose return type is non-reference".
> > As far as I can tell, that's why we don't need an std::move() in the
> > caller.
> 
> I see.. This seems to suggest both RVO and move semantic can play a
> role https://stackoverflow.com/a/46571941
> 
> Ah, c++
> 
> >> difficult to follow in my opinion.
> >
> > I think we should standardise as much as possible on std::unique_ptr<>
> > when passing ownership of a returned pointer. That's documented in
> > Documentation/coding-style.rst.
> 
> Ack, let's keep it the way it is then.
> 
> >>> +								int64_t timestamp)
> >>>  {
> >>> -	int ret;
> >>> -
> >>>  	/*
> >>>  	 * \todo Keep this in sync with the actual number of entries.
> >>>  	 * Currently: 13 entries, 36 bytes
> >>>  	 */
> >>> -	camera_metadata_t *resultMetadata = allocate_camera_metadata(15, 50);
> >>> +	std::unique_ptr<CameraMetadata> resultMetadata =
> >>> +		utils::make_unique<CameraMetadata>(15, 50);
> >>> +	if (!resultMetadata->isValid()) {
> >>> +		LOG(HAL, Error) << "Failed to allocate static metadata";
> >>> +		return nullptr;
> >>> +	}
> >>>
> >>>  	const uint8_t ae_state = ANDROID_CONTROL_AE_STATE_CONVERGED;
> >>> -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AE_STATE,
> >>> -					&ae_state, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	resultMetadata->addEntry(ANDROID_CONTROL_AE_STATE, &ae_state, 1);
> >>>
> >>>  	const uint8_t ae_lock = ANDROID_CONTROL_AE_LOCK_OFF;
> >>> -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AE_LOCK,
> >>> -					&ae_lock, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	resultMetadata->addEntry(ANDROID_CONTROL_AE_LOCK, &ae_lock, 1);
> >>>
> >>>  	uint8_t af_state = ANDROID_CONTROL_AF_STATE_INACTIVE;
> >>> -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AF_STATE,
> >>> -					&af_state, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	resultMetadata->addEntry(ANDROID_CONTROL_AF_STATE, &af_state, 1);
> >>>
> >>>  	const uint8_t awb_state = ANDROID_CONTROL_AWB_STATE_CONVERGED;
> >>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>> -					ANDROID_CONTROL_AWB_STATE,
> >>> -					&awb_state, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	resultMetadata->addEntry(ANDROID_CONTROL_AWB_STATE, &awb_state, 1);
> >>>
> >>>  	const uint8_t awb_lock = ANDROID_CONTROL_AWB_LOCK_OFF;
> >>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>> -					ANDROID_CONTROL_AWB_LOCK,
> >>> -					&awb_lock, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	resultMetadata->addEntry(ANDROID_CONTROL_AWB_LOCK, &awb_lock, 1);
> >>>
> >>>  	const uint8_t lens_state = ANDROID_LENS_STATE_STATIONARY;
> >>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>> -					ANDROID_LENS_STATE,
> >>> -					&lens_state, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	resultMetadata->addEntry(ANDROID_LENS_STATE, &lens_state, 1);
> >>>
> >>>  	int32_t sensorSizes[] = {
> >>>  		0, 0, 2560, 1920,
> >>>  	};
> >>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>> -					ANDROID_SCALER_CROP_REGION,
> >>> -					sensorSizes, 4);
> >>> -	METADATA_ASSERT(ret);
> >>> +	resultMetadata->addEntry(ANDROID_SCALER_CROP_REGION, sensorSizes, 4);
> >>>
> >>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>> -					ANDROID_SENSOR_TIMESTAMP,
> >>> -					&timestamp, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	resultMetadata->addEntry(ANDROID_SENSOR_TIMESTAMP, &timestamp, 1);
> >>>
> >>>  	/* 33.3 msec */
> >>>  	const int64_t rolling_shutter_skew = 33300000;
> >>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>> -					ANDROID_SENSOR_ROLLING_SHUTTER_SKEW,
> >>> -					&rolling_shutter_skew, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	resultMetadata->addEntry(ANDROID_SENSOR_ROLLING_SHUTTER_SKEW,
> >>> +				 &rolling_shutter_skew, 1);
> >>>
> >>>  	/* 16.6 msec */
> >>>  	const int64_t exposure_time = 16600000;
> >>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>> -					ANDROID_SENSOR_EXPOSURE_TIME,
> >>> -					&exposure_time, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	resultMetadata->addEntry(ANDROID_SENSOR_EXPOSURE_TIME,
> >>> +				 &exposure_time, 1);
> >>>
> >>>  	const uint8_t lens_shading_map_mode =
> >>>  				ANDROID_STATISTICS_LENS_SHADING_MAP_MODE_OFF;
> >>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>> -					ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
> >>> -					&lens_shading_map_mode, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	resultMetadata->addEntry(ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
> >>> +				 &lens_shading_map_mode, 1);
> >>>
> >>>  	const uint8_t scene_flicker = ANDROID_STATISTICS_SCENE_FLICKER_NONE;
> >>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>> -					ANDROID_STATISTICS_SCENE_FLICKER,
> >>> -					&scene_flicker, 1);
> >>> -	METADATA_ASSERT(ret);
> >>> +	resultMetadata->addEntry(ANDROID_STATISTICS_SCENE_FLICKER,
> >>> +				 &scene_flicker, 1);
> >>
> >> Shouldn't you check if the metadata pack is valid ?
> >
> > Good point. Should we check here or in the caller ? As the caller would
> > then need a nullptr check I'm tempted to do so in the caller. Actually,
> > without a change to the code, the caller will operate correctly I
> > believe
> >
> >                 resultMetadata = getResultMetadata(descriptor->frameNumber,
> >                                                    libcameraBuffer->timestamp());
> >                 captureResult.result = resultMetadata->get();
> >
> > which will set captureResult.result to nullptr if resultMetadata is not
> > valid.
> 
> Yeah, but in that case we should notify an error back to the stack.

That makes sense. It should be a faily uncommon case though, is it would
be the result of a bug in our code, but bugs happen. I wonder what the
proper error recovery would be in that case.

> What about:
> 
>         resultMetadata = getResultMetadata(descriptor->frameNumber,
>                                            libcameraBuffer->timestamp());
> 	if (status == CAMERA3_BUFFER_STATUS_ERROR || !resultMetadata) {
> 		/* \todo Improve error handling. */
> 		notifyError(descriptor->frameNumber,
> 			    descriptor->buffers[0].stream);
> 	} else {
> 		notifyShutter(descriptor->frameNumber,
> 			      libcameraBuffer->timestamp());
> 
> 		captureResult.partial_result = 1;
> 		captureResult.result = resultMetadata->get();
> 	}
> 
> The drawback is that we're generating the result metadata even if
> status is set to CAMERA3_BUFFER_STATUS_ERROR.

That I don't think we should do, as I expect the result metadata
generation will not be possible in case of CAMERA3_BUFFER_STATUS_ERROR
when we'll stop generating fake metadata.

How about this ?

	if (status == CAMERA3_BUFFER_STATUS_OK) {
		notifyShutter(descriptor->frameNumber,
			      libcameraBuffer->timestamp());

		captureResult.partial_result = 1;
		resultMetadata = getResultMetadata(descriptor->frameNumber,
						   libcameraBuffer->timestamp());
		captureResult.result = resultMetadata->get();
	}

	if (status == CAMERA3_BUFFER_STATUS_ERROR || !captureResult.result) {
		/* \todo Improve error handling. */
		notifyError(descriptor->frameNumber,
			    descriptor->buffers[0].stream);
	}

The last condition could be written if (!captureResult.result) as
CAMERA3_BUFFER_STATUS_ERROR implies !captureResult.result, but I'd
rather have both to make it explicit.

> >>>
> >>>  	return resultMetadata;
> >>>  }
> >>> diff --git a/src/android/camera_device.h b/src/android/camera_device.h
> >>> index 7897ba9dc5c7..65ba877a02ea 100644
> >>> --- a/src/android/camera_device.h
> >>> +++ b/src/android/camera_device.h
> >>> @@ -19,13 +19,7 @@
> >>>
> >>>  #include "message.h"
> >>>
> >>> -#define METADATA_ASSERT(_r)		\
> >>> -	do {				\
> >>> -		if (!(_r)) break;	\
> >>> -		LOG(HAL, Error) << "Error: " << __func__ << ":" << __LINE__; \
> >>> -		return nullptr;		\
> >>> -	} while(0);
> >>> -
> >>> +class CameraMetadata;
> >>>  class ThreadRpc;
> >>>
> >>>  class CameraDevice : public libcamera::Object
> >>> @@ -59,14 +53,15 @@ private:
> >>>
> >>>  	void notifyShutter(uint32_t frameNumber, uint64_t timestamp);
> >>>  	void notifyError(uint32_t frameNumber, camera3_stream_t *stream);
> >>> -	camera_metadata_t *getResultMetadata(int frame_number, int64_t timestamp);
> >>> +	std::unique_ptr<CameraMetadata> getResultMetadata(int frame_number,
> >>> +							  int64_t timestamp);
> >>>
> >>>  	bool running_;
> >>>  	std::shared_ptr<libcamera::Camera> camera_;
> >>>  	std::unique_ptr<libcamera::CameraConfiguration> config_;
> >>>
> >>> -	camera_metadata_t *staticMetadata_;
> >>> -	camera_metadata_t *requestTemplate_;
> >>> +	CameraMetadata *staticMetadata_;
> >>> +	CameraMetadata *requestTemplate_;
> >>>  	const camera3_callback_ops_t *callbacks_;
> >>>  };
> >>>
Jacopo Mondi Sept. 5, 2019, 8:25 p.m. UTC | #5
HI Laurent,

On Thu, Sep 05, 2019 at 01:02:59PM +0300, Laurent Pinchart wrote:
> Hi Jacopo,
>
> Thank you for the patch.
>
> On Thu, Sep 05, 2019 at 11:52:05AM +0200, Jacopo Mondi wrote:
> > On Thu, Sep 05, 2019 at 12:36:57PM +0300, Laurent Pinchart wrote:
> > > On Thu, Sep 05, 2019 at 10:18:28AM +0200, Jacopo Mondi wrote:
> > >> On Thu, Sep 05, 2019 at 09:47:34AM +0200, Jacopo Mondi wrote:
> > >>> From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > >>>
> > >>> Simplify the implementation of metadata handling in the CameraDevice
> > >>> class by using the new CameraMetadata helper class.
> > >>>
> > >>> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > >>> ---
> > >>>  src/android/camera_device.cpp | 507 +++++++++++++---------------------
> > >>>  src/android/camera_device.h   |  15 +-
> > >>>  2 files changed, 198 insertions(+), 324 deletions(-)
> > >>>
> > >>> diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
> > >>> index 5f8d19b9ef3d..475fa2404421 100644
> > >>> --- a/src/android/camera_device.cpp
> > >>> +++ b/src/android/camera_device.cpp
> > >>> @@ -7,10 +7,10 @@
> > >>>
> > >>>  #include "camera_device.h"
> > >>>
> > >>> -#include <system/camera_metadata.h>
> > >>> -
> > >>>  #include "log.h"
> > >>> +#include "utils.h"
> > >>>
> > >>> +#include "camera_metadata.h"
> > >>>  #include "thread_rpc.h"
> > >>>
> > >>>  using namespace libcamera;
> > >>> @@ -59,12 +59,10 @@ CameraDevice::CameraDevice(unsigned int id, const std::shared_ptr<Camera> &camer
> > >>>  CameraDevice::~CameraDevice()
> > >>>  {
> > >>>  	if (staticMetadata_)
> > >>> -		free_camera_metadata(staticMetadata_);
> > >>> -	staticMetadata_ = nullptr;
> > >>> +		delete staticMetadata_;
> > >>>
> > >>>  	if (requestTemplate_)
> > >>> -		free_camera_metadata(requestTemplate_);
> > >>> -	requestTemplate_ = nullptr;
> > >>> +		delete requestTemplate_;
> > >>>  }
> > >>>
> > >>>  /*
> > >>> @@ -117,10 +115,8 @@ void CameraDevice::setCallbacks(const camera3_callback_ops_t *callbacks)
> > >>>   */
> > >>>  camera_metadata_t *CameraDevice::getStaticMetadata()
> > >>>  {
> > >>> -	int ret;
> > >>> -
> > >>>  	if (staticMetadata_)
> > >>> -		return staticMetadata_;
> > >>> +		return staticMetadata_->get();
> > >>>
> > >>>  	/*
> > >>>  	 * The here reported metadata are enough to implement a basic capture
> > >>> @@ -132,16 +128,21 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> > >>>  	 * \todo Keep this in sync with the actual number of entries.
> > >>>  	 * Currently: 46 entries, 390 bytes
> > >>>  	 */
> > >>> -	staticMetadata_ = allocate_camera_metadata(50, 500);
> > >>> +	staticMetadata_ = new CameraMetadata(50, 500);
> > >>> +	if (!staticMetadata_->isValid()) {
> > >>> +		LOG(HAL, Error) << "Failed to allocate static metadata";
> > >>> +		delete staticMetadata_;
> > >>> +		staticMetadata_ = nullptr;
> > >>> +		return nullptr;
> > >>
> > >> Empty line before return?
> > >
> > > I don't mind either way, but I haven't added one as the delete,
> > > assignment to nullptr and return nullptr are logically grouped in my
> > > opinion. Feel free to add a blank line if you prefer.
> >
> > Ok, if this was intentional let's keep it the way it is.
> >
> > >>> +	}
> > >>>
> > >>>  	/* Color correction static metadata. */
> > >>>  	std::vector<uint8_t> aberrationModes = {
> > >>>  		ANDROID_COLOR_CORRECTION_ABERRATION_MODE_OFF,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES,
> > >>> -			aberrationModes.data(), aberrationModes.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES,
> > >>> +				  aberrationModes.data(),
> > >>> +				  aberrationModes.size());
> > >>>
> > >>>  	/* Control static metadata. */
> > >>>  	std::vector<uint8_t> aeAvailableAntiBandingModes = {
> > >>> @@ -150,294 +151,228 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> > >>>  		ANDROID_CONTROL_AE_ANTIBANDING_MODE_60HZ,
> > >>>  		ANDROID_CONTROL_AE_ANTIBANDING_MODE_AUTO,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES,
> > >>> -			aeAvailableAntiBandingModes.data(),
> > >>> -			aeAvailableAntiBandingModes.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES,
> > >>> +				  aeAvailableAntiBandingModes.data(),
> > >>> +				  aeAvailableAntiBandingModes.size());
> > >>>
> > >>>  	std::vector<uint8_t> aeAvailableModes = {
> > >>>  		ANDROID_CONTROL_AE_MODE_ON,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_CONTROL_AE_AVAILABLE_MODES,
> > >>> -			aeAvailableModes.data(), aeAvailableModes.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_MODES,
> > >>> +				  aeAvailableModes.data(),
> > >>> +				  aeAvailableModes.size());
> > >>>
> > >>>  	std::vector<int32_t> availableAeFpsTarget = {
> > >>>  		15, 30,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES,
> > >>> -			availableAeFpsTarget.data(),
> > >>> -			availableAeFpsTarget.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES,
> > >>> +				  availableAeFpsTarget.data(),
> > >>> +				  availableAeFpsTarget.size());
> > >>>
> > >>>  	std::vector<int32_t> aeCompensationRange = {
> > >>>  		0, 0,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_CONTROL_AE_COMPENSATION_RANGE,
> > >>> -			aeCompensationRange.data(),
> > >>> -			aeCompensationRange.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_COMPENSATION_RANGE,
> > >>> +				  aeCompensationRange.data(),
> > >>> +				  aeCompensationRange.size());
> > >>>
> > >>>  	const camera_metadata_rational_t aeCompensationStep[] = {
> > >>>  		{ 0, 1 }
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_CONTROL_AE_COMPENSATION_STEP,
> > >>> -			aeCompensationStep, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_COMPENSATION_STEP,
> > >>> +				  aeCompensationStep, 1);
> > >>>
> > >>>  	std::vector<uint8_t> availableAfModes = {
> > >>>  		ANDROID_CONTROL_AF_MODE_OFF,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_CONTROL_AF_AVAILABLE_MODES,
> > >>> -			availableAfModes.data(), availableAfModes.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AF_AVAILABLE_MODES,
> > >>> +				  availableAfModes.data(),
> > >>> +				  availableAfModes.size());
> > >>>
> > >>>  	std::vector<uint8_t> availableEffects = {
> > >>>  		ANDROID_CONTROL_EFFECT_MODE_OFF,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_CONTROL_AVAILABLE_EFFECTS,
> > >>> -			availableEffects.data(), availableEffects.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_EFFECTS,
> > >>> +				  availableEffects.data(),
> > >>> +				  availableEffects.size());
> > >>>
> > >>>  	std::vector<uint8_t> availableSceneModes = {
> > >>>  		ANDROID_CONTROL_SCENE_MODE_DISABLED,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_CONTROL_AVAILABLE_SCENE_MODES,
> > >>> -			availableSceneModes.data(), availableSceneModes.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_SCENE_MODES,
> > >>> +				  availableSceneModes.data(),
> > >>> +				  availableSceneModes.size());
> > >>>
> > >>>  	std::vector<uint8_t> availableStabilizationModes = {
> > >>>  		ANDROID_CONTROL_VIDEO_STABILIZATION_MODE_OFF,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES,
> > >>> -			availableStabilizationModes.data(),
> > >>> -			availableStabilizationModes.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES,
> > >>> +				  availableStabilizationModes.data(),
> > >>> +				  availableStabilizationModes.size());
> > >>>
> > >>>  	std::vector<uint8_t> availableAwbModes = {
> > >>>  		ANDROID_CONTROL_AWB_MODE_OFF,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_CONTROL_AWB_AVAILABLE_MODES,
> > >>> -			availableAwbModes.data(), availableAwbModes.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AWB_AVAILABLE_MODES,
> > >>> +				  availableAwbModes.data(),
> > >>> +				  availableAwbModes.size());
> > >>>
> > >>>  	std::vector<int32_t> availableMaxRegions = {
> > >>>  		0, 0, 0,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_CONTROL_MAX_REGIONS,
> > >>> -			availableMaxRegions.data(), availableMaxRegions.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_MAX_REGIONS,
> > >>> +				  availableMaxRegions.data(),
> > >>> +				  availableMaxRegions.size());
> > >>>
> > >>>  	std::vector<uint8_t> sceneModesOverride = {
> > >>>  		ANDROID_CONTROL_AE_MODE_ON,
> > >>>  		ANDROID_CONTROL_AWB_MODE_AUTO,
> > >>>  		ANDROID_CONTROL_AF_MODE_AUTO,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_CONTROL_SCENE_MODE_OVERRIDES,
> > >>> -			sceneModesOverride.data(), sceneModesOverride.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_SCENE_MODE_OVERRIDES,
> > >>> +				  sceneModesOverride.data(),
> > >>> +				  sceneModesOverride.size());
> > >>>
> > >>>  	uint8_t aeLockAvailable = ANDROID_CONTROL_AE_LOCK_AVAILABLE_FALSE;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_CONTROL_AE_LOCK_AVAILABLE,
> > >>> -			&aeLockAvailable, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_LOCK_AVAILABLE,
> > >>> +				  &aeLockAvailable, 1);
> > >>>
> > >>>  	uint8_t awbLockAvailable = ANDROID_CONTROL_AWB_LOCK_AVAILABLE_FALSE;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
> > >>> -			&awbLockAvailable, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
> > >>> +				  &awbLockAvailable, 1);
> > >>>
> > >>>  	char availableControlModes = ANDROID_CONTROL_MODE_AUTO;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_CONTROL_AVAILABLE_MODES,
> > >>> -			&availableControlModes, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_MODES,
> > >>> +				  &availableControlModes, 1);
> > >>>
> > >>>  	/* JPEG static metadata. */
> > >>>  	std::vector<int32_t> availableThumbnailSizes = {
> > >>>  		0, 0,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
> > >>> -			availableThumbnailSizes.data(),
> > >>> -			availableThumbnailSizes.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
> > >>> +				  availableThumbnailSizes.data(),
> > >>> +				  availableThumbnailSizes.size());
> > >>>
> > >>>  	/* Sensor static metadata. */
> > >>>  	int32_t pixelArraySize[] = {
> > >>>  		2592, 1944,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -				ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
> > >>> -				&pixelArraySize, 2);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
> > >>> +				  &pixelArraySize, 2);
> > >>>
> > >>>  	int32_t sensorSizes[] = {
> > >>>  		0, 0, 2560, 1920,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -				ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
> > >>> -				&sensorSizes, 4);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
> > >>> +				  &sensorSizes, 4);
> > >>>
> > >>>  	int32_t sensitivityRange[] = {
> > >>>  		32, 2400,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -				ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
> > >>> -				&sensitivityRange, 2);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
> > >>> +				  &sensitivityRange, 2);
> > >>>
> > >>>  	uint16_t filterArr = ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT_GRBG;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -				ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
> > >>> -				&filterArr, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
> > >>> +				  &filterArr, 1);
> > >>>
> > >>>  	int64_t exposureTimeRange[] = {
> > >>>  		100000, 200000000,
> > >>>  	};
> > >>
> > >> I've been thinking for a while to stabilize on the use of std::vector in
> > >> place of arrays, so e can always use .data() and .size() and have
> > >> guaranteed we should only change the declaration and not the
> > >> parameters to the addEntry() operation.
> > >>
> > >> This might be a good time to do so. What do you think?
> > >
> > > I've thought about it, and constructing a vector is a bit costly
> > > compared to arrays. I'd rather used std::array<>, but that requires
> > > specifying the size explicitly :-S I've been thinking about overloading
> > > the addEntry() method, in order to be able to write
> > >
> > > 	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> > > 				  { 100000, 200000000 });
> > >
> > > I'm not sure if that will be possible as we need to handle different
> > > data types, but I think it's worth a try. Other overloaded methods
> > > should also be added for the arrays of a single element:
> > >
> > > 	staticMetadata_->addEntry(ANDROID_SENSOR_ORIENTATION, 0);
> > >
> > > I would prefer handling the standardisation of vector vs. array in a
> > > separate patch, when dealing with overloaded versions of addEntry(), as
> > > this patch is big enough already.
> >
> > Agreed
> >
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -				ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> > >>> -				&exposureTimeRange, 2);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> > >>> +				  &exposureTimeRange, 2);
> > >>>
> > >>>  	int32_t orientation = 0;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -				ANDROID_SENSOR_ORIENTATION,
> > >>> -				&orientation, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_ORIENTATION,
> > >>> +				  &orientation, 1);
> > >>
> > >> Fits in 1 line
> > >
> > > I've kept it on two lines to use similar constructs through the whole
> > > function, but I don't mind much, so please feel free to change it if you
> > > prefer.
> >
> > If it was intentional, let's keep it the way it is
> >
> > >>>
> > >>>  	std::vector<int32_t> testPatterModes = {
> > >>>  		ANDROID_SENSOR_TEST_PATTERN_MODE_OFF,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -				ANDROID_SENSOR_AVAILABLE_TEST_PATTERN_MODES,
> > >>> -				testPatterModes.data(), testPatterModes.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_AVAILABLE_TEST_PATTERN_MODES,
> > >>> +				  testPatterModes.data(),
> > >>> +				  testPatterModes.size());
> > >>>
> > >>>  	std::vector<float> physicalSize = {
> > >>>  		2592, 1944,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -				ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
> > >>> -				physicalSize.data(), physicalSize.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
> > >>> +				  physicalSize.data(),
> > >>> +				  physicalSize.size());
> > >>
> > >> Fits in 1 line
> > >>
> > >>>
> > >>>  	uint8_t timestampSource = ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE_UNKNOWN;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE,
> > >>> -			&timestampSource, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE,
> > >>> +				  &timestampSource, 1);
> > >>>
> > >>>  	/* Statistics static metadata. */
> > >>>  	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
> > >>> -			&faceDetectMode, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
> > >>> +				  &faceDetectMode, 1);
> > >>>
> > >>>  	int32_t maxFaceCount = 0;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
> > >>> -			&maxFaceCount, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
> > >>> +				  &maxFaceCount, 1);
> > >>>
> > >>>  	/* Sync static metadata. */
> > >>>  	int32_t maxLatency = ANDROID_SYNC_MAX_LATENCY_UNKNOWN;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_SYNC_MAX_LATENCY, &maxLatency, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_SYNC_MAX_LATENCY, &maxLatency, 1);
> > >>>
> > >>>  	/* Flash static metadata. */
> > >>>  	char flashAvailable = ANDROID_FLASH_INFO_AVAILABLE_FALSE;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_FLASH_INFO_AVAILABLE,
> > >>> -			&flashAvailable, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_FLASH_INFO_AVAILABLE,
> > >>> +				  &flashAvailable, 1);
> > >>>
> > >>>  	/* Lens static metadata. */
> > >>>  	std::vector<float> lensApertures = {
> > >>>  		2.53 / 100,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -				ANDROID_LENS_INFO_AVAILABLE_APERTURES,
> > >>> -				lensApertures.data(), lensApertures.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_APERTURES,
> > >>> +				  lensApertures.data(),
> > >>> +				  lensApertures.size());
> > >>>
> > >>>  	uint8_t lensFacing = ANDROID_LENS_FACING_FRONT;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -				ANDROID_LENS_FACING, &lensFacing, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_LENS_FACING, &lensFacing, 1);
> > >>>
> > >>>  	std::vector<float> lensFocalLenghts = {
> > >>>  		1,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -				ANDROID_LENS_INFO_AVAILABLE_FOCAL_LENGTHS,
> > >>> -				lensFocalLenghts.data(),
> > >>> -				lensFocalLenghts.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_FOCAL_LENGTHS,
> > >>> +				  lensFocalLenghts.data(),
> > >>> +				  lensFocalLenghts.size());
> > >>>
> > >>>  	std::vector<uint8_t> opticalStabilizations = {
> > >>>  		ANDROID_LENS_OPTICAL_STABILIZATION_MODE_OFF,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -				ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
> > >>> -				opticalStabilizations.data(),
> > >>> -				opticalStabilizations.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
> > >>> +				  opticalStabilizations.data(),
> > >>> +				  opticalStabilizations.size());
> > >>>
> > >>>  	float hypeFocalDistance = 0;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -				ANDROID_LENS_INFO_HYPERFOCAL_DISTANCE,
> > >>> -				&hypeFocalDistance, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_HYPERFOCAL_DISTANCE,
> > >>> +				  &hypeFocalDistance, 1);
> > >>>
> > >>>  	float minFocusDistance = 0;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -				ANDROID_LENS_INFO_MINIMUM_FOCUS_DISTANCE,
> > >>> -				&minFocusDistance, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_MINIMUM_FOCUS_DISTANCE,
> > >>> +				  &minFocusDistance, 1);
> > >>>
> > >>>  	/* Noise reduction modes. */
> > >>>  	uint8_t noiseReductionModes = ANDROID_NOISE_REDUCTION_MODE_OFF;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -				ANDROID_NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES,
> > >>> -				&noiseReductionModes, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES,
> > >>> +				  &noiseReductionModes, 1);
> > >>>
> > >>>  	/* Scaler static metadata. */
> > >>>  	float maxDigitalZoom = 1;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_SCALER_AVAILABLE_MAX_DIGITAL_ZOOM,
> > >>> -			&maxDigitalZoom, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_MAX_DIGITAL_ZOOM,
> > >>> +				  &maxDigitalZoom, 1);
> > >>>
> > >>>  	std::vector<uint32_t> availableStreamFormats = {
> > >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB,
> > >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_YCbCr_420_888,
> > >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_SCALER_AVAILABLE_FORMATS,
> > >>> -			availableStreamFormats.data(),
> > >>> -			availableStreamFormats.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_FORMATS,
> > >>> +				  availableStreamFormats.data(),
> > >>> +				  availableStreamFormats.size());
> > >>>
> > >>>  	std::vector<uint32_t> availableStreamConfigurations = {
> > >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920,
> > >>> @@ -447,65 +382,57 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> > >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED, 2560, 1920,
> > >>>  		ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS_OUTPUT,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS,
> > >>> -			availableStreamConfigurations.data(),
> > >>> -			availableStreamConfigurations.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS,
> > >>> +				  availableStreamConfigurations.data(),
> > >>> +				  availableStreamConfigurations.size());
> > >>>
> > >>>  	std::vector<int64_t> availableStallDurations = {
> > >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920, 33333333,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_SCALER_AVAILABLE_STALL_DURATIONS,
> > >>> -			availableStallDurations.data(),
> > >>> -			availableStallDurations.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_STALL_DURATIONS,
> > >>> +				  availableStallDurations.data(),
> > >>> +				  availableStallDurations.size());
> > >>>
> > >>>  	std::vector<int64_t> minFrameDurations = {
> > >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920, 33333333,
> > >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED, 2560, 1920, 33333333,
> > >>>  		ANDROID_SCALER_AVAILABLE_FORMATS_YCbCr_420_888, 2560, 1920, 33333333,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_SCALER_AVAILABLE_MIN_FRAME_DURATIONS,
> > >>> -			minFrameDurations.data(), minFrameDurations.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_MIN_FRAME_DURATIONS,
> > >>> +				  minFrameDurations.data(),
> > >>> +				  minFrameDurations.size());
> > >>>
> > >>>  	uint8_t croppingType = ANDROID_SCALER_CROPPING_TYPE_CENTER_ONLY;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_SCALER_CROPPING_TYPE, &croppingType, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_SCALER_CROPPING_TYPE, &croppingType, 1);
> > >>>
> > >>>  	/* Info static metadata. */
> > >>>  	uint8_t supportedHWLevel = ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL,
> > >>> -			&supportedHWLevel, 1);
> > >>> +	staticMetadata_->addEntry(ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL,
> > >>> +				  &supportedHWLevel, 1);
> > >>>
> > >>>  	/* Request static metadata. */
> > >>>  	int32_t partialResultCount = 1;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_REQUEST_PARTIAL_RESULT_COUNT,
> > >>> -			&partialResultCount, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_REQUEST_PARTIAL_RESULT_COUNT,
> > >>> +				  &partialResultCount, 1);
> > >>>
> > >>>  	uint8_t maxPipelineDepth = 2;
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_REQUEST_PIPELINE_MAX_DEPTH,
> > >>> -			&maxPipelineDepth, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_REQUEST_PIPELINE_MAX_DEPTH,
> > >>> +				  &maxPipelineDepth, 1);
> > >>>
> > >>>  	std::vector<uint8_t> availableCapabilities = {
> > >>>  		ANDROID_REQUEST_AVAILABLE_CAPABILITIES_BACKWARD_COMPATIBLE,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>> -			ANDROID_REQUEST_AVAILABLE_CAPABILITIES,
> > >>> -			availableCapabilities.data(),
> > >>> -			availableCapabilities.size());
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	staticMetadata_->addEntry(ANDROID_REQUEST_AVAILABLE_CAPABILITIES,
> > >>> +				  availableCapabilities.data(),
> > >>> +				  availableCapabilities.size());
> > >>> +
> > >>> +	if (!staticMetadata_->isValid()) {
> > >>> +		delete staticMetadata_;
> > >>> +		staticMetadata_ = nullptr;
> > >>> +		return nullptr;
> > >>> +	}
> > >>>
> > >>> -	return staticMetadata_;
> > >>> +	return staticMetadata_->get();
> > >>>  }
> > >>>
> > >>>  /*
> > >>> @@ -513,8 +440,6 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> > >>>   */
> > >>>  const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
> > >>>  {
> > >>> -	int ret;
> > >>> -
> > >>>  	/*
> > >>>  	 * \todo Inspect type and pick the right metadata pack.
> > >>>  	 * As of now just use a single one for all templates.
> > >>> @@ -545,89 +470,73 @@ const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
> > >>>  	}
> > >>>
> > >>>  	if (requestTemplate_)
> > >>> -		return requestTemplate_;
> > >>> +		return requestTemplate_->get();
> > >>>
> > >>>  	/*
> > >>>  	 * \todo Keep this in sync with the actual number of entries.
> > >>>  	 * Currently: 12 entries, 15 bytes
> > >>>  	 */
> > >>> -	requestTemplate_ = allocate_camera_metadata(15, 20);
> > >>> +	requestTemplate_ = new CameraMetadata(15, 20);
> > >>>  	if (!requestTemplate_) {
> > >>>  		LOG(HAL, Error) << "Failed to allocate template metadata";
> > >>> +		delete requestTemplate_;
> > >>> +		requestTemplate_ = nullptr;
> > >>
> > >> Empty line before return ?
> > >>
> > >>>  		return nullptr;
> > >>>  	}
> > >>>
> > >>>  	uint8_t aeMode = ANDROID_CONTROL_AE_MODE_ON;
> > >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>> -			ANDROID_CONTROL_AE_MODE,
> > >>> -			&aeMode, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_MODE,
> > >>> +				   &aeMode, 1);
> > >>
> > >> This and many others entries here and below fit in 1 line.
> > >>
> > >>>
> > >>>  	int32_t aeExposureCompensation = 0;
> > >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>> -			ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION,
> > >>> -			&aeExposureCompensation, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION,
> > >>> +				   &aeExposureCompensation, 1);
> > >>>
> > >>>  	uint8_t aePrecaptureTrigger = ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER_IDLE;
> > >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>> -			ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER,
> > >>> -			&aePrecaptureTrigger, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER,
> > >>> +				   &aePrecaptureTrigger, 1);
> > >>>
> > >>>  	uint8_t aeLock = ANDROID_CONTROL_AE_LOCK_OFF;
> > >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>> -			ANDROID_CONTROL_AE_LOCK,
> > >>> -			&aeLock, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_LOCK,
> > >>> +				   &aeLock, 1);
> > >>>
> > >>>  	uint8_t afTrigger = ANDROID_CONTROL_AF_TRIGGER_IDLE;
> > >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>> -			ANDROID_CONTROL_AF_TRIGGER,
> > >>> -			&afTrigger, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AF_TRIGGER,
> > >>> +				   &afTrigger, 1);
> > >>>
> > >>>  	uint8_t awbMode = ANDROID_CONTROL_AWB_MODE_AUTO;
> > >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>> -			ANDROID_CONTROL_AWB_MODE,
> > >>> -			&awbMode, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AWB_MODE,
> > >>> +				   &awbMode, 1);
> > >>>
> > >>>  	uint8_t awbLock = ANDROID_CONTROL_AWB_LOCK_OFF;
> > >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>> -			ANDROID_CONTROL_AWB_LOCK,
> > >>> -			&awbLock, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AWB_LOCK,
> > >>> +				   &awbLock, 1);
> > >>>
> > >>>  	uint8_t flashMode = ANDROID_FLASH_MODE_OFF;
> > >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>> -			ANDROID_FLASH_MODE,
> > >>> -			&flashMode, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	requestTemplate_->addEntry(ANDROID_FLASH_MODE,
> > >>> +				   &flashMode, 1);
> > >>>
> > >>>  	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
> > >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>> -			ANDROID_STATISTICS_FACE_DETECT_MODE,
> > >>> -			&faceDetectMode, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	requestTemplate_->addEntry(ANDROID_STATISTICS_FACE_DETECT_MODE,
> > >>> +				   &faceDetectMode, 1);
> > >>>
> > >>>  	uint8_t noiseReduction = ANDROID_NOISE_REDUCTION_MODE_OFF;
> > >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>> -			ANDROID_NOISE_REDUCTION_MODE, &noiseReduction, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	requestTemplate_->addEntry(ANDROID_NOISE_REDUCTION_MODE,
> > >>> +				   &noiseReduction, 1);
> > >>>
> > >>>  	uint8_t aberrationMode = ANDROID_COLOR_CORRECTION_ABERRATION_MODE_OFF;
> > >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>> -			ANDROID_COLOR_CORRECTION_ABERRATION_MODE,
> > >>> -			&aberrationMode, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	requestTemplate_->addEntry(ANDROID_COLOR_CORRECTION_ABERRATION_MODE,
> > >>> +				   &aberrationMode, 1);
> > >>> +
> > >>> +	requestTemplate_->addEntry(ANDROID_CONTROL_CAPTURE_INTENT,
> > >>> +				   &captureIntent, 1);
> > >>>
> > >>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>> -			ANDROID_CONTROL_CAPTURE_INTENT,
> > >>> -			&captureIntent, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	if (!requestTemplate_->isValid()) {
> > >>> +		delete requestTemplate_;
> > >>> +		requestTemplate_ = nullptr;
> > >>
> > >> You should return nullptr here, otherwise the below requestTemplate_->get();
> > >> will de-reference a nullptr.
> > >
> > > Absolutely, my bad.
> > >
> > >>> +	}
> > >>>
> > >>> -	return requestTemplate_;
> > >>> +	return requestTemplate_->get();
> > >>>  }
> > >>>
> > >>>  /*
> > >>> @@ -799,7 +708,7 @@ void CameraDevice::requestComplete(Request *request,
> > >>>  {
> > >>>  	Buffer *libcameraBuffer = buffers.begin()->second;
> > >>>  	camera3_buffer_status status = CAMERA3_BUFFER_STATUS_OK;
> > >>> -	camera_metadata_t *resultMetadata = nullptr;
> > >>> +	std::unique_ptr<CameraMetadata> resultMetadata;
> > >>>
> > >>>  	if (request->status() != Request::RequestComplete) {
> > >>>  		LOG(HAL, Error) << "Request not succesfully completed: "
> > >>> @@ -837,16 +746,12 @@ void CameraDevice::requestComplete(Request *request,
> > >>>  		captureResult.partial_result = 1;
> > >>>  		resultMetadata = getResultMetadata(descriptor->frameNumber,
> > >>>  						   libcameraBuffer->timestamp());
> > >>> -		captureResult.result = resultMetadata;
> > >>> +		captureResult.result = resultMetadata->get();
> > >>>  	}
> > >>>
> > >>>  	callbacks_->process_capture_result(callbacks_, &captureResult);
> > >>>
> > >>>  	delete descriptor;
> > >>> -	if (resultMetadata)
> > >>> -		free_camera_metadata(resultMetadata);
> > >>> -
> > >>> -	return;
> > >>>  }
> > >>>
> > >>>  void CameraDevice::notifyShutter(uint32_t frameNumber, uint64_t timestamp)
> > >>> @@ -875,89 +780,63 @@ void CameraDevice::notifyError(uint32_t frameNumber, camera3_stream_t *stream)
> > >>>  /*
> > >>>   * Produce a set of fixed result metadata.
> > >>>   */
> > >>> -camera_metadata_t *CameraDevice::getResultMetadata(int frame_number,
> > >>> -						   int64_t timestamp)
> > >>> +std::unique_ptr<CameraMetadata> CameraDevice::getResultMetadata(int frame_number,
> > >>
> > >> Not a fan of smart pointers, you know already. How does this work?
> > >> Because the compiler applies copy-elision or because of the move
> > >> semantic applied on the return value?
> > >
> > > std::unique_ptr<> has an operator= that takes an rvalue reference to
> > > another std::unique_ptr<>, and uses move semantic. As explained in
> > > https://en.cppreference.com/w/cpp/language/value_category, an rvalue is
> > > either a prvalue or an xvalue, and a prvalue can be "a function call or
> > > an overloaded operator expression, whose return type is non-reference".
> > > As far as I can tell, that's why we don't need an std::move() in the
> > > caller.
> >
> > I see.. This seems to suggest both RVO and move semantic can play a
> > role https://stackoverflow.com/a/46571941
> >
> > Ah, c++
> >
> > >> difficult to follow in my opinion.
> > >
> > > I think we should standardise as much as possible on std::unique_ptr<>
> > > when passing ownership of a returned pointer. That's documented in
> > > Documentation/coding-style.rst.
> >
> > Ack, let's keep it the way it is then.
> >
> > >>> +								int64_t timestamp)
> > >>>  {
> > >>> -	int ret;
> > >>> -
> > >>>  	/*
> > >>>  	 * \todo Keep this in sync with the actual number of entries.
> > >>>  	 * Currently: 13 entries, 36 bytes
> > >>>  	 */
> > >>> -	camera_metadata_t *resultMetadata = allocate_camera_metadata(15, 50);
> > >>> +	std::unique_ptr<CameraMetadata> resultMetadata =
> > >>> +		utils::make_unique<CameraMetadata>(15, 50);
> > >>> +	if (!resultMetadata->isValid()) {
> > >>> +		LOG(HAL, Error) << "Failed to allocate static metadata";
> > >>> +		return nullptr;
> > >>> +	}
> > >>>
> > >>>  	const uint8_t ae_state = ANDROID_CONTROL_AE_STATE_CONVERGED;
> > >>> -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AE_STATE,
> > >>> -					&ae_state, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	resultMetadata->addEntry(ANDROID_CONTROL_AE_STATE, &ae_state, 1);
> > >>>
> > >>>  	const uint8_t ae_lock = ANDROID_CONTROL_AE_LOCK_OFF;
> > >>> -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AE_LOCK,
> > >>> -					&ae_lock, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	resultMetadata->addEntry(ANDROID_CONTROL_AE_LOCK, &ae_lock, 1);
> > >>>
> > >>>  	uint8_t af_state = ANDROID_CONTROL_AF_STATE_INACTIVE;
> > >>> -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AF_STATE,
> > >>> -					&af_state, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	resultMetadata->addEntry(ANDROID_CONTROL_AF_STATE, &af_state, 1);
> > >>>
> > >>>  	const uint8_t awb_state = ANDROID_CONTROL_AWB_STATE_CONVERGED;
> > >>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>> -					ANDROID_CONTROL_AWB_STATE,
> > >>> -					&awb_state, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	resultMetadata->addEntry(ANDROID_CONTROL_AWB_STATE, &awb_state, 1);
> > >>>
> > >>>  	const uint8_t awb_lock = ANDROID_CONTROL_AWB_LOCK_OFF;
> > >>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>> -					ANDROID_CONTROL_AWB_LOCK,
> > >>> -					&awb_lock, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	resultMetadata->addEntry(ANDROID_CONTROL_AWB_LOCK, &awb_lock, 1);
> > >>>
> > >>>  	const uint8_t lens_state = ANDROID_LENS_STATE_STATIONARY;
> > >>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>> -					ANDROID_LENS_STATE,
> > >>> -					&lens_state, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	resultMetadata->addEntry(ANDROID_LENS_STATE, &lens_state, 1);
> > >>>
> > >>>  	int32_t sensorSizes[] = {
> > >>>  		0, 0, 2560, 1920,
> > >>>  	};
> > >>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>> -					ANDROID_SCALER_CROP_REGION,
> > >>> -					sensorSizes, 4);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	resultMetadata->addEntry(ANDROID_SCALER_CROP_REGION, sensorSizes, 4);
> > >>>
> > >>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>> -					ANDROID_SENSOR_TIMESTAMP,
> > >>> -					&timestamp, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	resultMetadata->addEntry(ANDROID_SENSOR_TIMESTAMP, &timestamp, 1);
> > >>>
> > >>>  	/* 33.3 msec */
> > >>>  	const int64_t rolling_shutter_skew = 33300000;
> > >>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>> -					ANDROID_SENSOR_ROLLING_SHUTTER_SKEW,
> > >>> -					&rolling_shutter_skew, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	resultMetadata->addEntry(ANDROID_SENSOR_ROLLING_SHUTTER_SKEW,
> > >>> +				 &rolling_shutter_skew, 1);
> > >>>
> > >>>  	/* 16.6 msec */
> > >>>  	const int64_t exposure_time = 16600000;
> > >>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>> -					ANDROID_SENSOR_EXPOSURE_TIME,
> > >>> -					&exposure_time, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	resultMetadata->addEntry(ANDROID_SENSOR_EXPOSURE_TIME,
> > >>> +				 &exposure_time, 1);
> > >>>
> > >>>  	const uint8_t lens_shading_map_mode =
> > >>>  				ANDROID_STATISTICS_LENS_SHADING_MAP_MODE_OFF;
> > >>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>> -					ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
> > >>> -					&lens_shading_map_mode, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	resultMetadata->addEntry(ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
> > >>> +				 &lens_shading_map_mode, 1);
> > >>>
> > >>>  	const uint8_t scene_flicker = ANDROID_STATISTICS_SCENE_FLICKER_NONE;
> > >>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>> -					ANDROID_STATISTICS_SCENE_FLICKER,
> > >>> -					&scene_flicker, 1);
> > >>> -	METADATA_ASSERT(ret);
> > >>> +	resultMetadata->addEntry(ANDROID_STATISTICS_SCENE_FLICKER,
> > >>> +				 &scene_flicker, 1);
> > >>
> > >> Shouldn't you check if the metadata pack is valid ?
> > >
> > > Good point. Should we check here or in the caller ? As the caller would
> > > then need a nullptr check I'm tempted to do so in the caller. Actually,
> > > without a change to the code, the caller will operate correctly I
> > > believe
> > >
> > >                 resultMetadata = getResultMetadata(descriptor->frameNumber,
> > >                                                    libcameraBuffer->timestamp());
> > >                 captureResult.result = resultMetadata->get();
> > >
> > > which will set captureResult.result to nullptr if resultMetadata is not
> > > valid.
> >
> > Yeah, but in that case we should notify an error back to the stack.
>
> That makes sense. It should be a faily uncommon case though, is it would
> be the result of a bug in our code, but bugs happen. I wonder what the
> proper error recovery would be in that case.
>
> > What about:
> >
> >         resultMetadata = getResultMetadata(descriptor->frameNumber,
> >                                            libcameraBuffer->timestamp());
> > 	if (status == CAMERA3_BUFFER_STATUS_ERROR || !resultMetadata) {
> > 		/* \todo Improve error handling. */
> > 		notifyError(descriptor->frameNumber,
> > 			    descriptor->buffers[0].stream);
> > 	} else {
> > 		notifyShutter(descriptor->frameNumber,
> > 			      libcameraBuffer->timestamp());
> >
> > 		captureResult.partial_result = 1;
> > 		captureResult.result = resultMetadata->get();
> > 	}
> >
> > The drawback is that we're generating the result metadata even if
> > status is set to CAMERA3_BUFFER_STATUS_ERROR.
>
> That I don't think we should do, as I expect the result metadata
> generation will not be possible in case of CAMERA3_BUFFER_STATUS_ERROR
> when we'll stop generating fake metadata.
>
> How about this ?
>
> 	if (status == CAMERA3_BUFFER_STATUS_OK) {
> 		notifyShutter(descriptor->frameNumber,
> 			      libcameraBuffer->timestamp());
>
> 		captureResult.partial_result = 1;
> 		resultMetadata = getResultMetadata(descriptor->frameNumber,
> 						   libcameraBuffer->timestamp());
> 		captureResult.result = resultMetadata->get();
> 	}
>
> 	if (status == CAMERA3_BUFFER_STATUS_ERROR || !captureResult.result) {
> 		/* \todo Improve error handling. */
> 		notifyError(descriptor->frameNumber,
> 			    descriptor->buffers[0].stream);
> 	}
>
> The last condition could be written if (!captureResult.result) as
> CAMERA3_BUFFER_STATUS_ERROR implies !captureResult.result, but I'd
> rather have both to make it explicit.
>

The only difference I see here is that we send up a shutter event and
the if metadata generation fails we send back an error.

In the previous version was either an error or the shutter
notification, not both.

I can't tell if this makes any difference to the camera stack to be
honest.

Thanks
   j

> > >>>
> > >>>  	return resultMetadata;
> > >>>  }
> > >>> diff --git a/src/android/camera_device.h b/src/android/camera_device.h
> > >>> index 7897ba9dc5c7..65ba877a02ea 100644
> > >>> --- a/src/android/camera_device.h
> > >>> +++ b/src/android/camera_device.h
> > >>> @@ -19,13 +19,7 @@
> > >>>
> > >>>  #include "message.h"
> > >>>
> > >>> -#define METADATA_ASSERT(_r)		\
> > >>> -	do {				\
> > >>> -		if (!(_r)) break;	\
> > >>> -		LOG(HAL, Error) << "Error: " << __func__ << ":" << __LINE__; \
> > >>> -		return nullptr;		\
> > >>> -	} while(0);
> > >>> -
> > >>> +class CameraMetadata;
> > >>>  class ThreadRpc;
> > >>>
> > >>>  class CameraDevice : public libcamera::Object
> > >>> @@ -59,14 +53,15 @@ private:
> > >>>
> > >>>  	void notifyShutter(uint32_t frameNumber, uint64_t timestamp);
> > >>>  	void notifyError(uint32_t frameNumber, camera3_stream_t *stream);
> > >>> -	camera_metadata_t *getResultMetadata(int frame_number, int64_t timestamp);
> > >>> +	std::unique_ptr<CameraMetadata> getResultMetadata(int frame_number,
> > >>> +							  int64_t timestamp);
> > >>>
> > >>>  	bool running_;
> > >>>  	std::shared_ptr<libcamera::Camera> camera_;
> > >>>  	std::unique_ptr<libcamera::CameraConfiguration> config_;
> > >>>
> > >>> -	camera_metadata_t *staticMetadata_;
> > >>> -	camera_metadata_t *requestTemplate_;
> > >>> +	CameraMetadata *staticMetadata_;
> > >>> +	CameraMetadata *requestTemplate_;
> > >>>  	const camera3_callback_ops_t *callbacks_;
> > >>>  };
> > >>>
>
> --
> Regards,
>
> Laurent Pinchart
Laurent Pinchart Sept. 5, 2019, 8:39 p.m. UTC | #6
Hi Jacopo,

On Thu, Sep 05, 2019 at 10:25:03PM +0200, Jacopo Mondi wrote:
> On Thu, Sep 05, 2019 at 01:02:59PM +0300, Laurent Pinchart wrote:
> > On Thu, Sep 05, 2019 at 11:52:05AM +0200, Jacopo Mondi wrote:
> >> On Thu, Sep 05, 2019 at 12:36:57PM +0300, Laurent Pinchart wrote:
> >>> On Thu, Sep 05, 2019 at 10:18:28AM +0200, Jacopo Mondi wrote:
> >>>> On Thu, Sep 05, 2019 at 09:47:34AM +0200, Jacopo Mondi wrote:
> >>>>> From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >>>>>
> >>>>> Simplify the implementation of metadata handling in the CameraDevice
> >>>>> class by using the new CameraMetadata helper class.
> >>>>>
> >>>>> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >>>>> ---
> >>>>>  src/android/camera_device.cpp | 507 +++++++++++++---------------------
> >>>>>  src/android/camera_device.h   |  15 +-
> >>>>>  2 files changed, 198 insertions(+), 324 deletions(-)
> >>>>>
> >>>>> diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
> >>>>> index 5f8d19b9ef3d..475fa2404421 100644
> >>>>> --- a/src/android/camera_device.cpp
> >>>>> +++ b/src/android/camera_device.cpp
> >>>>> @@ -7,10 +7,10 @@
> >>>>>
> >>>>>  #include "camera_device.h"
> >>>>>
> >>>>> -#include <system/camera_metadata.h>
> >>>>> -
> >>>>>  #include "log.h"
> >>>>> +#include "utils.h"
> >>>>>
> >>>>> +#include "camera_metadata.h"
> >>>>>  #include "thread_rpc.h"
> >>>>>
> >>>>>  using namespace libcamera;
> >>>>> @@ -59,12 +59,10 @@ CameraDevice::CameraDevice(unsigned int id, const std::shared_ptr<Camera> &camer
> >>>>>  CameraDevice::~CameraDevice()
> >>>>>  {
> >>>>>  	if (staticMetadata_)
> >>>>> -		free_camera_metadata(staticMetadata_);
> >>>>> -	staticMetadata_ = nullptr;
> >>>>> +		delete staticMetadata_;
> >>>>>
> >>>>>  	if (requestTemplate_)
> >>>>> -		free_camera_metadata(requestTemplate_);
> >>>>> -	requestTemplate_ = nullptr;
> >>>>> +		delete requestTemplate_;
> >>>>>  }
> >>>>>
> >>>>>  /*
> >>>>> @@ -117,10 +115,8 @@ void CameraDevice::setCallbacks(const camera3_callback_ops_t *callbacks)
> >>>>>   */
> >>>>>  camera_metadata_t *CameraDevice::getStaticMetadata()
> >>>>>  {
> >>>>> -	int ret;
> >>>>> -
> >>>>>  	if (staticMetadata_)
> >>>>> -		return staticMetadata_;
> >>>>> +		return staticMetadata_->get();
> >>>>>
> >>>>>  	/*
> >>>>>  	 * The here reported metadata are enough to implement a basic capture
> >>>>> @@ -132,16 +128,21 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> >>>>>  	 * \todo Keep this in sync with the actual number of entries.
> >>>>>  	 * Currently: 46 entries, 390 bytes
> >>>>>  	 */
> >>>>> -	staticMetadata_ = allocate_camera_metadata(50, 500);
> >>>>> +	staticMetadata_ = new CameraMetadata(50, 500);
> >>>>> +	if (!staticMetadata_->isValid()) {
> >>>>> +		LOG(HAL, Error) << "Failed to allocate static metadata";
> >>>>> +		delete staticMetadata_;
> >>>>> +		staticMetadata_ = nullptr;
> >>>>> +		return nullptr;
> >>>>
> >>>> Empty line before return?
> >>>
> >>> I don't mind either way, but I haven't added one as the delete,
> >>> assignment to nullptr and return nullptr are logically grouped in my
> >>> opinion. Feel free to add a blank line if you prefer.
> >>
> >> Ok, if this was intentional let's keep it the way it is.
> >>
> >>>>> +	}
> >>>>>
> >>>>>  	/* Color correction static metadata. */
> >>>>>  	std::vector<uint8_t> aberrationModes = {
> >>>>>  		ANDROID_COLOR_CORRECTION_ABERRATION_MODE_OFF,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES,
> >>>>> -			aberrationModes.data(), aberrationModes.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES,
> >>>>> +				  aberrationModes.data(),
> >>>>> +				  aberrationModes.size());
> >>>>>
> >>>>>  	/* Control static metadata. */
> >>>>>  	std::vector<uint8_t> aeAvailableAntiBandingModes = {
> >>>>> @@ -150,294 +151,228 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> >>>>>  		ANDROID_CONTROL_AE_ANTIBANDING_MODE_60HZ,
> >>>>>  		ANDROID_CONTROL_AE_ANTIBANDING_MODE_AUTO,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES,
> >>>>> -			aeAvailableAntiBandingModes.data(),
> >>>>> -			aeAvailableAntiBandingModes.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES,
> >>>>> +				  aeAvailableAntiBandingModes.data(),
> >>>>> +				  aeAvailableAntiBandingModes.size());
> >>>>>
> >>>>>  	std::vector<uint8_t> aeAvailableModes = {
> >>>>>  		ANDROID_CONTROL_AE_MODE_ON,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_CONTROL_AE_AVAILABLE_MODES,
> >>>>> -			aeAvailableModes.data(), aeAvailableModes.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_MODES,
> >>>>> +				  aeAvailableModes.data(),
> >>>>> +				  aeAvailableModes.size());
> >>>>>
> >>>>>  	std::vector<int32_t> availableAeFpsTarget = {
> >>>>>  		15, 30,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES,
> >>>>> -			availableAeFpsTarget.data(),
> >>>>> -			availableAeFpsTarget.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES,
> >>>>> +				  availableAeFpsTarget.data(),
> >>>>> +				  availableAeFpsTarget.size());
> >>>>>
> >>>>>  	std::vector<int32_t> aeCompensationRange = {
> >>>>>  		0, 0,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_CONTROL_AE_COMPENSATION_RANGE,
> >>>>> -			aeCompensationRange.data(),
> >>>>> -			aeCompensationRange.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_COMPENSATION_RANGE,
> >>>>> +				  aeCompensationRange.data(),
> >>>>> +				  aeCompensationRange.size());
> >>>>>
> >>>>>  	const camera_metadata_rational_t aeCompensationStep[] = {
> >>>>>  		{ 0, 1 }
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_CONTROL_AE_COMPENSATION_STEP,
> >>>>> -			aeCompensationStep, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_COMPENSATION_STEP,
> >>>>> +				  aeCompensationStep, 1);
> >>>>>
> >>>>>  	std::vector<uint8_t> availableAfModes = {
> >>>>>  		ANDROID_CONTROL_AF_MODE_OFF,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_CONTROL_AF_AVAILABLE_MODES,
> >>>>> -			availableAfModes.data(), availableAfModes.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AF_AVAILABLE_MODES,
> >>>>> +				  availableAfModes.data(),
> >>>>> +				  availableAfModes.size());
> >>>>>
> >>>>>  	std::vector<uint8_t> availableEffects = {
> >>>>>  		ANDROID_CONTROL_EFFECT_MODE_OFF,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_CONTROL_AVAILABLE_EFFECTS,
> >>>>> -			availableEffects.data(), availableEffects.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_EFFECTS,
> >>>>> +				  availableEffects.data(),
> >>>>> +				  availableEffects.size());
> >>>>>
> >>>>>  	std::vector<uint8_t> availableSceneModes = {
> >>>>>  		ANDROID_CONTROL_SCENE_MODE_DISABLED,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_CONTROL_AVAILABLE_SCENE_MODES,
> >>>>> -			availableSceneModes.data(), availableSceneModes.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_SCENE_MODES,
> >>>>> +				  availableSceneModes.data(),
> >>>>> +				  availableSceneModes.size());
> >>>>>
> >>>>>  	std::vector<uint8_t> availableStabilizationModes = {
> >>>>>  		ANDROID_CONTROL_VIDEO_STABILIZATION_MODE_OFF,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES,
> >>>>> -			availableStabilizationModes.data(),
> >>>>> -			availableStabilizationModes.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES,
> >>>>> +				  availableStabilizationModes.data(),
> >>>>> +				  availableStabilizationModes.size());
> >>>>>
> >>>>>  	std::vector<uint8_t> availableAwbModes = {
> >>>>>  		ANDROID_CONTROL_AWB_MODE_OFF,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_CONTROL_AWB_AVAILABLE_MODES,
> >>>>> -			availableAwbModes.data(), availableAwbModes.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AWB_AVAILABLE_MODES,
> >>>>> +				  availableAwbModes.data(),
> >>>>> +				  availableAwbModes.size());
> >>>>>
> >>>>>  	std::vector<int32_t> availableMaxRegions = {
> >>>>>  		0, 0, 0,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_CONTROL_MAX_REGIONS,
> >>>>> -			availableMaxRegions.data(), availableMaxRegions.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_MAX_REGIONS,
> >>>>> +				  availableMaxRegions.data(),
> >>>>> +				  availableMaxRegions.size());
> >>>>>
> >>>>>  	std::vector<uint8_t> sceneModesOverride = {
> >>>>>  		ANDROID_CONTROL_AE_MODE_ON,
> >>>>>  		ANDROID_CONTROL_AWB_MODE_AUTO,
> >>>>>  		ANDROID_CONTROL_AF_MODE_AUTO,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_CONTROL_SCENE_MODE_OVERRIDES,
> >>>>> -			sceneModesOverride.data(), sceneModesOverride.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_SCENE_MODE_OVERRIDES,
> >>>>> +				  sceneModesOverride.data(),
> >>>>> +				  sceneModesOverride.size());
> >>>>>
> >>>>>  	uint8_t aeLockAvailable = ANDROID_CONTROL_AE_LOCK_AVAILABLE_FALSE;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_CONTROL_AE_LOCK_AVAILABLE,
> >>>>> -			&aeLockAvailable, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_LOCK_AVAILABLE,
> >>>>> +				  &aeLockAvailable, 1);
> >>>>>
> >>>>>  	uint8_t awbLockAvailable = ANDROID_CONTROL_AWB_LOCK_AVAILABLE_FALSE;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
> >>>>> -			&awbLockAvailable, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
> >>>>> +				  &awbLockAvailable, 1);
> >>>>>
> >>>>>  	char availableControlModes = ANDROID_CONTROL_MODE_AUTO;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_CONTROL_AVAILABLE_MODES,
> >>>>> -			&availableControlModes, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_MODES,
> >>>>> +				  &availableControlModes, 1);
> >>>>>
> >>>>>  	/* JPEG static metadata. */
> >>>>>  	std::vector<int32_t> availableThumbnailSizes = {
> >>>>>  		0, 0,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
> >>>>> -			availableThumbnailSizes.data(),
> >>>>> -			availableThumbnailSizes.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
> >>>>> +				  availableThumbnailSizes.data(),
> >>>>> +				  availableThumbnailSizes.size());
> >>>>>
> >>>>>  	/* Sensor static metadata. */
> >>>>>  	int32_t pixelArraySize[] = {
> >>>>>  		2592, 1944,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -				ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
> >>>>> -				&pixelArraySize, 2);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
> >>>>> +				  &pixelArraySize, 2);
> >>>>>
> >>>>>  	int32_t sensorSizes[] = {
> >>>>>  		0, 0, 2560, 1920,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -				ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
> >>>>> -				&sensorSizes, 4);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
> >>>>> +				  &sensorSizes, 4);
> >>>>>
> >>>>>  	int32_t sensitivityRange[] = {
> >>>>>  		32, 2400,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -				ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
> >>>>> -				&sensitivityRange, 2);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
> >>>>> +				  &sensitivityRange, 2);
> >>>>>
> >>>>>  	uint16_t filterArr = ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT_GRBG;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -				ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
> >>>>> -				&filterArr, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
> >>>>> +				  &filterArr, 1);
> >>>>>
> >>>>>  	int64_t exposureTimeRange[] = {
> >>>>>  		100000, 200000000,
> >>>>>  	};
> >>>>
> >>>> I've been thinking for a while to stabilize on the use of std::vector in
> >>>> place of arrays, so e can always use .data() and .size() and have
> >>>> guaranteed we should only change the declaration and not the
> >>>> parameters to the addEntry() operation.
> >>>>
> >>>> This might be a good time to do so. What do you think?
> >>>
> >>> I've thought about it, and constructing a vector is a bit costly
> >>> compared to arrays. I'd rather used std::array<>, but that requires
> >>> specifying the size explicitly :-S I've been thinking about overloading
> >>> the addEntry() method, in order to be able to write
> >>>
> >>> 	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> >>> 				  { 100000, 200000000 });
> >>>
> >>> I'm not sure if that will be possible as we need to handle different
> >>> data types, but I think it's worth a try. Other overloaded methods
> >>> should also be added for the arrays of a single element:
> >>>
> >>> 	staticMetadata_->addEntry(ANDROID_SENSOR_ORIENTATION, 0);
> >>>
> >>> I would prefer handling the standardisation of vector vs. array in a
> >>> separate patch, when dealing with overloaded versions of addEntry(), as
> >>> this patch is big enough already.
> >>
> >> Agreed
> >>
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -				ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> >>>>> -				&exposureTimeRange, 2);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> >>>>> +				  &exposureTimeRange, 2);
> >>>>>
> >>>>>  	int32_t orientation = 0;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -				ANDROID_SENSOR_ORIENTATION,
> >>>>> -				&orientation, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_ORIENTATION,
> >>>>> +				  &orientation, 1);
> >>>>
> >>>> Fits in 1 line
> >>>
> >>> I've kept it on two lines to use similar constructs through the whole
> >>> function, but I don't mind much, so please feel free to change it if you
> >>> prefer.
> >>
> >> If it was intentional, let's keep it the way it is
> >>
> >>>>>
> >>>>>  	std::vector<int32_t> testPatterModes = {
> >>>>>  		ANDROID_SENSOR_TEST_PATTERN_MODE_OFF,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -				ANDROID_SENSOR_AVAILABLE_TEST_PATTERN_MODES,
> >>>>> -				testPatterModes.data(), testPatterModes.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_AVAILABLE_TEST_PATTERN_MODES,
> >>>>> +				  testPatterModes.data(),
> >>>>> +				  testPatterModes.size());
> >>>>>
> >>>>>  	std::vector<float> physicalSize = {
> >>>>>  		2592, 1944,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -				ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
> >>>>> -				physicalSize.data(), physicalSize.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
> >>>>> +				  physicalSize.data(),
> >>>>> +				  physicalSize.size());
> >>>>
> >>>> Fits in 1 line
> >>>>
> >>>>>
> >>>>>  	uint8_t timestampSource = ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE_UNKNOWN;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE,
> >>>>> -			&timestampSource, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE,
> >>>>> +				  &timestampSource, 1);
> >>>>>
> >>>>>  	/* Statistics static metadata. */
> >>>>>  	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
> >>>>> -			&faceDetectMode, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
> >>>>> +				  &faceDetectMode, 1);
> >>>>>
> >>>>>  	int32_t maxFaceCount = 0;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
> >>>>> -			&maxFaceCount, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
> >>>>> +				  &maxFaceCount, 1);
> >>>>>
> >>>>>  	/* Sync static metadata. */
> >>>>>  	int32_t maxLatency = ANDROID_SYNC_MAX_LATENCY_UNKNOWN;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_SYNC_MAX_LATENCY, &maxLatency, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_SYNC_MAX_LATENCY, &maxLatency, 1);
> >>>>>
> >>>>>  	/* Flash static metadata. */
> >>>>>  	char flashAvailable = ANDROID_FLASH_INFO_AVAILABLE_FALSE;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_FLASH_INFO_AVAILABLE,
> >>>>> -			&flashAvailable, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_FLASH_INFO_AVAILABLE,
> >>>>> +				  &flashAvailable, 1);
> >>>>>
> >>>>>  	/* Lens static metadata. */
> >>>>>  	std::vector<float> lensApertures = {
> >>>>>  		2.53 / 100,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -				ANDROID_LENS_INFO_AVAILABLE_APERTURES,
> >>>>> -				lensApertures.data(), lensApertures.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_APERTURES,
> >>>>> +				  lensApertures.data(),
> >>>>> +				  lensApertures.size());
> >>>>>
> >>>>>  	uint8_t lensFacing = ANDROID_LENS_FACING_FRONT;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -				ANDROID_LENS_FACING, &lensFacing, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_LENS_FACING, &lensFacing, 1);
> >>>>>
> >>>>>  	std::vector<float> lensFocalLenghts = {
> >>>>>  		1,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -				ANDROID_LENS_INFO_AVAILABLE_FOCAL_LENGTHS,
> >>>>> -				lensFocalLenghts.data(),
> >>>>> -				lensFocalLenghts.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_FOCAL_LENGTHS,
> >>>>> +				  lensFocalLenghts.data(),
> >>>>> +				  lensFocalLenghts.size());
> >>>>>
> >>>>>  	std::vector<uint8_t> opticalStabilizations = {
> >>>>>  		ANDROID_LENS_OPTICAL_STABILIZATION_MODE_OFF,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -				ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
> >>>>> -				opticalStabilizations.data(),
> >>>>> -				opticalStabilizations.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
> >>>>> +				  opticalStabilizations.data(),
> >>>>> +				  opticalStabilizations.size());
> >>>>>
> >>>>>  	float hypeFocalDistance = 0;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -				ANDROID_LENS_INFO_HYPERFOCAL_DISTANCE,
> >>>>> -				&hypeFocalDistance, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_HYPERFOCAL_DISTANCE,
> >>>>> +				  &hypeFocalDistance, 1);
> >>>>>
> >>>>>  	float minFocusDistance = 0;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -				ANDROID_LENS_INFO_MINIMUM_FOCUS_DISTANCE,
> >>>>> -				&minFocusDistance, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_MINIMUM_FOCUS_DISTANCE,
> >>>>> +				  &minFocusDistance, 1);
> >>>>>
> >>>>>  	/* Noise reduction modes. */
> >>>>>  	uint8_t noiseReductionModes = ANDROID_NOISE_REDUCTION_MODE_OFF;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -				ANDROID_NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES,
> >>>>> -				&noiseReductionModes, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES,
> >>>>> +				  &noiseReductionModes, 1);
> >>>>>
> >>>>>  	/* Scaler static metadata. */
> >>>>>  	float maxDigitalZoom = 1;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_SCALER_AVAILABLE_MAX_DIGITAL_ZOOM,
> >>>>> -			&maxDigitalZoom, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_MAX_DIGITAL_ZOOM,
> >>>>> +				  &maxDigitalZoom, 1);
> >>>>>
> >>>>>  	std::vector<uint32_t> availableStreamFormats = {
> >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB,
> >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_YCbCr_420_888,
> >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_SCALER_AVAILABLE_FORMATS,
> >>>>> -			availableStreamFormats.data(),
> >>>>> -			availableStreamFormats.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_FORMATS,
> >>>>> +				  availableStreamFormats.data(),
> >>>>> +				  availableStreamFormats.size());
> >>>>>
> >>>>>  	std::vector<uint32_t> availableStreamConfigurations = {
> >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920,
> >>>>> @@ -447,65 +382,57 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED, 2560, 1920,
> >>>>>  		ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS_OUTPUT,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS,
> >>>>> -			availableStreamConfigurations.data(),
> >>>>> -			availableStreamConfigurations.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS,
> >>>>> +				  availableStreamConfigurations.data(),
> >>>>> +				  availableStreamConfigurations.size());
> >>>>>
> >>>>>  	std::vector<int64_t> availableStallDurations = {
> >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920, 33333333,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_SCALER_AVAILABLE_STALL_DURATIONS,
> >>>>> -			availableStallDurations.data(),
> >>>>> -			availableStallDurations.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_STALL_DURATIONS,
> >>>>> +				  availableStallDurations.data(),
> >>>>> +				  availableStallDurations.size());
> >>>>>
> >>>>>  	std::vector<int64_t> minFrameDurations = {
> >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920, 33333333,
> >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED, 2560, 1920, 33333333,
> >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_YCbCr_420_888, 2560, 1920, 33333333,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_SCALER_AVAILABLE_MIN_FRAME_DURATIONS,
> >>>>> -			minFrameDurations.data(), minFrameDurations.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_MIN_FRAME_DURATIONS,
> >>>>> +				  minFrameDurations.data(),
> >>>>> +				  minFrameDurations.size());
> >>>>>
> >>>>>  	uint8_t croppingType = ANDROID_SCALER_CROPPING_TYPE_CENTER_ONLY;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_SCALER_CROPPING_TYPE, &croppingType, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_SCALER_CROPPING_TYPE, &croppingType, 1);
> >>>>>
> >>>>>  	/* Info static metadata. */
> >>>>>  	uint8_t supportedHWLevel = ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL,
> >>>>> -			&supportedHWLevel, 1);
> >>>>> +	staticMetadata_->addEntry(ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL,
> >>>>> +				  &supportedHWLevel, 1);
> >>>>>
> >>>>>  	/* Request static metadata. */
> >>>>>  	int32_t partialResultCount = 1;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_REQUEST_PARTIAL_RESULT_COUNT,
> >>>>> -			&partialResultCount, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_REQUEST_PARTIAL_RESULT_COUNT,
> >>>>> +				  &partialResultCount, 1);
> >>>>>
> >>>>>  	uint8_t maxPipelineDepth = 2;
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_REQUEST_PIPELINE_MAX_DEPTH,
> >>>>> -			&maxPipelineDepth, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_REQUEST_PIPELINE_MAX_DEPTH,
> >>>>> +				  &maxPipelineDepth, 1);
> >>>>>
> >>>>>  	std::vector<uint8_t> availableCapabilities = {
> >>>>>  		ANDROID_REQUEST_AVAILABLE_CAPABILITIES_BACKWARD_COMPATIBLE,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> >>>>> -			ANDROID_REQUEST_AVAILABLE_CAPABILITIES,
> >>>>> -			availableCapabilities.data(),
> >>>>> -			availableCapabilities.size());
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	staticMetadata_->addEntry(ANDROID_REQUEST_AVAILABLE_CAPABILITIES,
> >>>>> +				  availableCapabilities.data(),
> >>>>> +				  availableCapabilities.size());
> >>>>> +
> >>>>> +	if (!staticMetadata_->isValid()) {
> >>>>> +		delete staticMetadata_;
> >>>>> +		staticMetadata_ = nullptr;
> >>>>> +		return nullptr;
> >>>>> +	}
> >>>>>
> >>>>> -	return staticMetadata_;
> >>>>> +	return staticMetadata_->get();
> >>>>>  }
> >>>>>
> >>>>>  /*
> >>>>> @@ -513,8 +440,6 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> >>>>>   */
> >>>>>  const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
> >>>>>  {
> >>>>> -	int ret;
> >>>>> -
> >>>>>  	/*
> >>>>>  	 * \todo Inspect type and pick the right metadata pack.
> >>>>>  	 * As of now just use a single one for all templates.
> >>>>> @@ -545,89 +470,73 @@ const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
> >>>>>  	}
> >>>>>
> >>>>>  	if (requestTemplate_)
> >>>>> -		return requestTemplate_;
> >>>>> +		return requestTemplate_->get();
> >>>>>
> >>>>>  	/*
> >>>>>  	 * \todo Keep this in sync with the actual number of entries.
> >>>>>  	 * Currently: 12 entries, 15 bytes
> >>>>>  	 */
> >>>>> -	requestTemplate_ = allocate_camera_metadata(15, 20);
> >>>>> +	requestTemplate_ = new CameraMetadata(15, 20);
> >>>>>  	if (!requestTemplate_) {
> >>>>>  		LOG(HAL, Error) << "Failed to allocate template metadata";
> >>>>> +		delete requestTemplate_;
> >>>>> +		requestTemplate_ = nullptr;
> >>>>
> >>>> Empty line before return ?
> >>>>
> >>>>>  		return nullptr;
> >>>>>  	}
> >>>>>
> >>>>>  	uint8_t aeMode = ANDROID_CONTROL_AE_MODE_ON;
> >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>>>> -			ANDROID_CONTROL_AE_MODE,
> >>>>> -			&aeMode, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_MODE,
> >>>>> +				   &aeMode, 1);
> >>>>
> >>>> This and many others entries here and below fit in 1 line.
> >>>>
> >>>>>
> >>>>>  	int32_t aeExposureCompensation = 0;
> >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>>>> -			ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION,
> >>>>> -			&aeExposureCompensation, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION,
> >>>>> +				   &aeExposureCompensation, 1);
> >>>>>
> >>>>>  	uint8_t aePrecaptureTrigger = ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER_IDLE;
> >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>>>> -			ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER,
> >>>>> -			&aePrecaptureTrigger, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER,
> >>>>> +				   &aePrecaptureTrigger, 1);
> >>>>>
> >>>>>  	uint8_t aeLock = ANDROID_CONTROL_AE_LOCK_OFF;
> >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>>>> -			ANDROID_CONTROL_AE_LOCK,
> >>>>> -			&aeLock, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_LOCK,
> >>>>> +				   &aeLock, 1);
> >>>>>
> >>>>>  	uint8_t afTrigger = ANDROID_CONTROL_AF_TRIGGER_IDLE;
> >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>>>> -			ANDROID_CONTROL_AF_TRIGGER,
> >>>>> -			&afTrigger, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AF_TRIGGER,
> >>>>> +				   &afTrigger, 1);
> >>>>>
> >>>>>  	uint8_t awbMode = ANDROID_CONTROL_AWB_MODE_AUTO;
> >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>>>> -			ANDROID_CONTROL_AWB_MODE,
> >>>>> -			&awbMode, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AWB_MODE,
> >>>>> +				   &awbMode, 1);
> >>>>>
> >>>>>  	uint8_t awbLock = ANDROID_CONTROL_AWB_LOCK_OFF;
> >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>>>> -			ANDROID_CONTROL_AWB_LOCK,
> >>>>> -			&awbLock, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AWB_LOCK,
> >>>>> +				   &awbLock, 1);
> >>>>>
> >>>>>  	uint8_t flashMode = ANDROID_FLASH_MODE_OFF;
> >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>>>> -			ANDROID_FLASH_MODE,
> >>>>> -			&flashMode, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	requestTemplate_->addEntry(ANDROID_FLASH_MODE,
> >>>>> +				   &flashMode, 1);
> >>>>>
> >>>>>  	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
> >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>>>> -			ANDROID_STATISTICS_FACE_DETECT_MODE,
> >>>>> -			&faceDetectMode, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	requestTemplate_->addEntry(ANDROID_STATISTICS_FACE_DETECT_MODE,
> >>>>> +				   &faceDetectMode, 1);
> >>>>>
> >>>>>  	uint8_t noiseReduction = ANDROID_NOISE_REDUCTION_MODE_OFF;
> >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>>>> -			ANDROID_NOISE_REDUCTION_MODE, &noiseReduction, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	requestTemplate_->addEntry(ANDROID_NOISE_REDUCTION_MODE,
> >>>>> +				   &noiseReduction, 1);
> >>>>>
> >>>>>  	uint8_t aberrationMode = ANDROID_COLOR_CORRECTION_ABERRATION_MODE_OFF;
> >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>>>> -			ANDROID_COLOR_CORRECTION_ABERRATION_MODE,
> >>>>> -			&aberrationMode, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	requestTemplate_->addEntry(ANDROID_COLOR_CORRECTION_ABERRATION_MODE,
> >>>>> +				   &aberrationMode, 1);
> >>>>> +
> >>>>> +	requestTemplate_->addEntry(ANDROID_CONTROL_CAPTURE_INTENT,
> >>>>> +				   &captureIntent, 1);
> >>>>>
> >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> >>>>> -			ANDROID_CONTROL_CAPTURE_INTENT,
> >>>>> -			&captureIntent, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	if (!requestTemplate_->isValid()) {
> >>>>> +		delete requestTemplate_;
> >>>>> +		requestTemplate_ = nullptr;
> >>>>
> >>>> You should return nullptr here, otherwise the below requestTemplate_->get();
> >>>> will de-reference a nullptr.
> >>>
> >>> Absolutely, my bad.
> >>>
> >>>>> +	}
> >>>>>
> >>>>> -	return requestTemplate_;
> >>>>> +	return requestTemplate_->get();
> >>>>>  }
> >>>>>
> >>>>>  /*
> >>>>> @@ -799,7 +708,7 @@ void CameraDevice::requestComplete(Request *request,
> >>>>>  {
> >>>>>  	Buffer *libcameraBuffer = buffers.begin()->second;
> >>>>>  	camera3_buffer_status status = CAMERA3_BUFFER_STATUS_OK;
> >>>>> -	camera_metadata_t *resultMetadata = nullptr;
> >>>>> +	std::unique_ptr<CameraMetadata> resultMetadata;
> >>>>>
> >>>>>  	if (request->status() != Request::RequestComplete) {
> >>>>>  		LOG(HAL, Error) << "Request not succesfully completed: "
> >>>>> @@ -837,16 +746,12 @@ void CameraDevice::requestComplete(Request *request,
> >>>>>  		captureResult.partial_result = 1;
> >>>>>  		resultMetadata = getResultMetadata(descriptor->frameNumber,
> >>>>>  						   libcameraBuffer->timestamp());
> >>>>> -		captureResult.result = resultMetadata;
> >>>>> +		captureResult.result = resultMetadata->get();
> >>>>>  	}
> >>>>>
> >>>>>  	callbacks_->process_capture_result(callbacks_, &captureResult);
> >>>>>
> >>>>>  	delete descriptor;
> >>>>> -	if (resultMetadata)
> >>>>> -		free_camera_metadata(resultMetadata);
> >>>>> -
> >>>>> -	return;
> >>>>>  }
> >>>>>
> >>>>>  void CameraDevice::notifyShutter(uint32_t frameNumber, uint64_t timestamp)
> >>>>> @@ -875,89 +780,63 @@ void CameraDevice::notifyError(uint32_t frameNumber, camera3_stream_t *stream)
> >>>>>  /*
> >>>>>   * Produce a set of fixed result metadata.
> >>>>>   */
> >>>>> -camera_metadata_t *CameraDevice::getResultMetadata(int frame_number,
> >>>>> -						   int64_t timestamp)
> >>>>> +std::unique_ptr<CameraMetadata> CameraDevice::getResultMetadata(int frame_number,
> >>>>
> >>>> Not a fan of smart pointers, you know already. How does this work?
> >>>> Because the compiler applies copy-elision or because of the move
> >>>> semantic applied on the return value?
> >>>
> >>> std::unique_ptr<> has an operator= that takes an rvalue reference to
> >>> another std::unique_ptr<>, and uses move semantic. As explained in
> >>> https://en.cppreference.com/w/cpp/language/value_category, an rvalue is
> >>> either a prvalue or an xvalue, and a prvalue can be "a function call or
> >>> an overloaded operator expression, whose return type is non-reference".
> >>> As far as I can tell, that's why we don't need an std::move() in the
> >>> caller.
> >>
> >> I see.. This seems to suggest both RVO and move semantic can play a
> >> role https://stackoverflow.com/a/46571941
> >>
> >> Ah, c++
> >>
> >>>> difficult to follow in my opinion.
> >>>
> >>> I think we should standardise as much as possible on std::unique_ptr<>
> >>> when passing ownership of a returned pointer. That's documented in
> >>> Documentation/coding-style.rst.
> >>
> >> Ack, let's keep it the way it is then.
> >>
> >>>>> +								int64_t timestamp)
> >>>>>  {
> >>>>> -	int ret;
> >>>>> -
> >>>>>  	/*
> >>>>>  	 * \todo Keep this in sync with the actual number of entries.
> >>>>>  	 * Currently: 13 entries, 36 bytes
> >>>>>  	 */
> >>>>> -	camera_metadata_t *resultMetadata = allocate_camera_metadata(15, 50);
> >>>>> +	std::unique_ptr<CameraMetadata> resultMetadata =
> >>>>> +		utils::make_unique<CameraMetadata>(15, 50);
> >>>>> +	if (!resultMetadata->isValid()) {
> >>>>> +		LOG(HAL, Error) << "Failed to allocate static metadata";
> >>>>> +		return nullptr;
> >>>>> +	}
> >>>>>
> >>>>>  	const uint8_t ae_state = ANDROID_CONTROL_AE_STATE_CONVERGED;
> >>>>> -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AE_STATE,
> >>>>> -					&ae_state, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	resultMetadata->addEntry(ANDROID_CONTROL_AE_STATE, &ae_state, 1);
> >>>>>
> >>>>>  	const uint8_t ae_lock = ANDROID_CONTROL_AE_LOCK_OFF;
> >>>>> -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AE_LOCK,
> >>>>> -					&ae_lock, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	resultMetadata->addEntry(ANDROID_CONTROL_AE_LOCK, &ae_lock, 1);
> >>>>>
> >>>>>  	uint8_t af_state = ANDROID_CONTROL_AF_STATE_INACTIVE;
> >>>>> -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AF_STATE,
> >>>>> -					&af_state, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	resultMetadata->addEntry(ANDROID_CONTROL_AF_STATE, &af_state, 1);
> >>>>>
> >>>>>  	const uint8_t awb_state = ANDROID_CONTROL_AWB_STATE_CONVERGED;
> >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>>>> -					ANDROID_CONTROL_AWB_STATE,
> >>>>> -					&awb_state, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	resultMetadata->addEntry(ANDROID_CONTROL_AWB_STATE, &awb_state, 1);
> >>>>>
> >>>>>  	const uint8_t awb_lock = ANDROID_CONTROL_AWB_LOCK_OFF;
> >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>>>> -					ANDROID_CONTROL_AWB_LOCK,
> >>>>> -					&awb_lock, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	resultMetadata->addEntry(ANDROID_CONTROL_AWB_LOCK, &awb_lock, 1);
> >>>>>
> >>>>>  	const uint8_t lens_state = ANDROID_LENS_STATE_STATIONARY;
> >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>>>> -					ANDROID_LENS_STATE,
> >>>>> -					&lens_state, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	resultMetadata->addEntry(ANDROID_LENS_STATE, &lens_state, 1);
> >>>>>
> >>>>>  	int32_t sensorSizes[] = {
> >>>>>  		0, 0, 2560, 1920,
> >>>>>  	};
> >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>>>> -					ANDROID_SCALER_CROP_REGION,
> >>>>> -					sensorSizes, 4);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	resultMetadata->addEntry(ANDROID_SCALER_CROP_REGION, sensorSizes, 4);
> >>>>>
> >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>>>> -					ANDROID_SENSOR_TIMESTAMP,
> >>>>> -					&timestamp, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	resultMetadata->addEntry(ANDROID_SENSOR_TIMESTAMP, &timestamp, 1);
> >>>>>
> >>>>>  	/* 33.3 msec */
> >>>>>  	const int64_t rolling_shutter_skew = 33300000;
> >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>>>> -					ANDROID_SENSOR_ROLLING_SHUTTER_SKEW,
> >>>>> -					&rolling_shutter_skew, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	resultMetadata->addEntry(ANDROID_SENSOR_ROLLING_SHUTTER_SKEW,
> >>>>> +				 &rolling_shutter_skew, 1);
> >>>>>
> >>>>>  	/* 16.6 msec */
> >>>>>  	const int64_t exposure_time = 16600000;
> >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>>>> -					ANDROID_SENSOR_EXPOSURE_TIME,
> >>>>> -					&exposure_time, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	resultMetadata->addEntry(ANDROID_SENSOR_EXPOSURE_TIME,
> >>>>> +				 &exposure_time, 1);
> >>>>>
> >>>>>  	const uint8_t lens_shading_map_mode =
> >>>>>  				ANDROID_STATISTICS_LENS_SHADING_MAP_MODE_OFF;
> >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>>>> -					ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
> >>>>> -					&lens_shading_map_mode, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	resultMetadata->addEntry(ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
> >>>>> +				 &lens_shading_map_mode, 1);
> >>>>>
> >>>>>  	const uint8_t scene_flicker = ANDROID_STATISTICS_SCENE_FLICKER_NONE;
> >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> >>>>> -					ANDROID_STATISTICS_SCENE_FLICKER,
> >>>>> -					&scene_flicker, 1);
> >>>>> -	METADATA_ASSERT(ret);
> >>>>> +	resultMetadata->addEntry(ANDROID_STATISTICS_SCENE_FLICKER,
> >>>>> +				 &scene_flicker, 1);
> >>>>
> >>>> Shouldn't you check if the metadata pack is valid ?
> >>>
> >>> Good point. Should we check here or in the caller ? As the caller would
> >>> then need a nullptr check I'm tempted to do so in the caller. Actually,
> >>> without a change to the code, the caller will operate correctly I
> >>> believe
> >>>
> >>>                 resultMetadata = getResultMetadata(descriptor->frameNumber,
> >>>                                                    libcameraBuffer->timestamp());
> >>>                 captureResult.result = resultMetadata->get();
> >>>
> >>> which will set captureResult.result to nullptr if resultMetadata is not
> >>> valid.
> >>
> >> Yeah, but in that case we should notify an error back to the stack.
> >
> > That makes sense. It should be a faily uncommon case though, is it would
> > be the result of a bug in our code, but bugs happen. I wonder what the
> > proper error recovery would be in that case.
> >
> >> What about:
> >>
> >>         resultMetadata = getResultMetadata(descriptor->frameNumber,
> >>                                            libcameraBuffer->timestamp());
> >> 	if (status == CAMERA3_BUFFER_STATUS_ERROR || !resultMetadata) {
> >> 		/* \todo Improve error handling. */
> >> 		notifyError(descriptor->frameNumber,
> >> 			    descriptor->buffers[0].stream);
> >> 	} else {
> >> 		notifyShutter(descriptor->frameNumber,
> >> 			      libcameraBuffer->timestamp());
> >>
> >> 		captureResult.partial_result = 1;
> >> 		captureResult.result = resultMetadata->get();
> >> 	}
> >>
> >> The drawback is that we're generating the result metadata even if
> >> status is set to CAMERA3_BUFFER_STATUS_ERROR.
> >
> > That I don't think we should do, as I expect the result metadata
> > generation will not be possible in case of CAMERA3_BUFFER_STATUS_ERROR
> > when we'll stop generating fake metadata.
> >
> > How about this ?
> >
> > 	if (status == CAMERA3_BUFFER_STATUS_OK) {
> > 		notifyShutter(descriptor->frameNumber,
> > 			      libcameraBuffer->timestamp());
> >
> > 		captureResult.partial_result = 1;
> > 		resultMetadata = getResultMetadata(descriptor->frameNumber,
> > 						   libcameraBuffer->timestamp());
> > 		captureResult.result = resultMetadata->get();
> > 	}
> >
> > 	if (status == CAMERA3_BUFFER_STATUS_ERROR || !captureResult.result) {
> > 		/* \todo Improve error handling. */
> > 		notifyError(descriptor->frameNumber,
> > 			    descriptor->buffers[0].stream);
> > 	}
> >
> > The last condition could be written if (!captureResult.result) as
> > CAMERA3_BUFFER_STATUS_ERROR implies !captureResult.result, but I'd
> > rather have both to make it explicit.
> 
> The only difference I see here is that we send up a shutter event and
> the if metadata generation fails we send back an error.
> 
> In the previous version was either an error or the shutter
> notification, not both.
> 
> I can't tell if this makes any difference to the camera stack to be
> honest.

Neither can I, and this shouldn't happen in the first place :-) If you
want to avoid it,

 	if (status == CAMERA3_BUFFER_STATUS_OK) {
 		captureResult.partial_result = 1;
 		resultMetadata = getResultMetadata(descriptor->frameNumber,
 						   libcameraBuffer->timestamp());
 		captureResult.result = resultMetadata->get();
 	}

 	if (status == CAMERA3_BUFFER_STATUS_OK && captureResult.result) {
 		notifyShutter(descriptor->frameNumber,
 			      libcameraBuffer->timestamp());
	} else {
 		/* \todo Improve error handling. */
 		notifyError(descriptor->frameNumber,
 			    descriptor->buffers[0].stream);
 	}

> >>>>>
> >>>>>  	return resultMetadata;
> >>>>>  }
> >>>>> diff --git a/src/android/camera_device.h b/src/android/camera_device.h
> >>>>> index 7897ba9dc5c7..65ba877a02ea 100644
> >>>>> --- a/src/android/camera_device.h
> >>>>> +++ b/src/android/camera_device.h
> >>>>> @@ -19,13 +19,7 @@
> >>>>>
> >>>>>  #include "message.h"
> >>>>>
> >>>>> -#define METADATA_ASSERT(_r)		\
> >>>>> -	do {				\
> >>>>> -		if (!(_r)) break;	\
> >>>>> -		LOG(HAL, Error) << "Error: " << __func__ << ":" << __LINE__; \
> >>>>> -		return nullptr;		\
> >>>>> -	} while(0);
> >>>>> -
> >>>>> +class CameraMetadata;
> >>>>>  class ThreadRpc;
> >>>>>
> >>>>>  class CameraDevice : public libcamera::Object
> >>>>> @@ -59,14 +53,15 @@ private:
> >>>>>
> >>>>>  	void notifyShutter(uint32_t frameNumber, uint64_t timestamp);
> >>>>>  	void notifyError(uint32_t frameNumber, camera3_stream_t *stream);
> >>>>> -	camera_metadata_t *getResultMetadata(int frame_number, int64_t timestamp);
> >>>>> +	std::unique_ptr<CameraMetadata> getResultMetadata(int frame_number,
> >>>>> +							  int64_t timestamp);
> >>>>>
> >>>>>  	bool running_;
> >>>>>  	std::shared_ptr<libcamera::Camera> camera_;
> >>>>>  	std::unique_ptr<libcamera::CameraConfiguration> config_;
> >>>>>
> >>>>> -	camera_metadata_t *staticMetadata_;
> >>>>> -	camera_metadata_t *requestTemplate_;
> >>>>> +	CameraMetadata *staticMetadata_;
> >>>>> +	CameraMetadata *requestTemplate_;
> >>>>>  	const camera3_callback_ops_t *callbacks_;
> >>>>>  };
> >>>>>
Jacopo Mondi Sept. 5, 2019, 9:20 p.m. UTC | #7
Hi Laurent,

On Thu, Sep 05, 2019 at 11:39:17PM +0300, Laurent Pinchart wrote:
> Hi Jacopo,
>
> On Thu, Sep 05, 2019 at 10:25:03PM +0200, Jacopo Mondi wrote:
> > On Thu, Sep 05, 2019 at 01:02:59PM +0300, Laurent Pinchart wrote:
> > > On Thu, Sep 05, 2019 at 11:52:05AM +0200, Jacopo Mondi wrote:
> > >> On Thu, Sep 05, 2019 at 12:36:57PM +0300, Laurent Pinchart wrote:
> > >>> On Thu, Sep 05, 2019 at 10:18:28AM +0200, Jacopo Mondi wrote:
> > >>>> On Thu, Sep 05, 2019 at 09:47:34AM +0200, Jacopo Mondi wrote:
> > >>>>> From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > >>>>>
> > >>>>> Simplify the implementation of metadata handling in the CameraDevice
> > >>>>> class by using the new CameraMetadata helper class.
> > >>>>>
> > >>>>> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > >>>>> ---
> > >>>>>  src/android/camera_device.cpp | 507 +++++++++++++---------------------
> > >>>>>  src/android/camera_device.h   |  15 +-
> > >>>>>  2 files changed, 198 insertions(+), 324 deletions(-)
> > >>>>>
> > >>>>> diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
> > >>>>> index 5f8d19b9ef3d..475fa2404421 100644
> > >>>>> --- a/src/android/camera_device.cpp
> > >>>>> +++ b/src/android/camera_device.cpp
> > >>>>> @@ -7,10 +7,10 @@
> > >>>>>
> > >>>>>  #include "camera_device.h"
> > >>>>>
> > >>>>> -#include <system/camera_metadata.h>
> > >>>>> -
> > >>>>>  #include "log.h"
> > >>>>> +#include "utils.h"
> > >>>>>
> > >>>>> +#include "camera_metadata.h"
> > >>>>>  #include "thread_rpc.h"
> > >>>>>
> > >>>>>  using namespace libcamera;
> > >>>>> @@ -59,12 +59,10 @@ CameraDevice::CameraDevice(unsigned int id, const std::shared_ptr<Camera> &camer
> > >>>>>  CameraDevice::~CameraDevice()
> > >>>>>  {
> > >>>>>  	if (staticMetadata_)
> > >>>>> -		free_camera_metadata(staticMetadata_);
> > >>>>> -	staticMetadata_ = nullptr;
> > >>>>> +		delete staticMetadata_;
> > >>>>>
> > >>>>>  	if (requestTemplate_)
> > >>>>> -		free_camera_metadata(requestTemplate_);
> > >>>>> -	requestTemplate_ = nullptr;
> > >>>>> +		delete requestTemplate_;
> > >>>>>  }
> > >>>>>
> > >>>>>  /*
> > >>>>> @@ -117,10 +115,8 @@ void CameraDevice::setCallbacks(const camera3_callback_ops_t *callbacks)
> > >>>>>   */
> > >>>>>  camera_metadata_t *CameraDevice::getStaticMetadata()
> > >>>>>  {
> > >>>>> -	int ret;
> > >>>>> -
> > >>>>>  	if (staticMetadata_)
> > >>>>> -		return staticMetadata_;
> > >>>>> +		return staticMetadata_->get();
> > >>>>>
> > >>>>>  	/*
> > >>>>>  	 * The here reported metadata are enough to implement a basic capture
> > >>>>> @@ -132,16 +128,21 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> > >>>>>  	 * \todo Keep this in sync with the actual number of entries.
> > >>>>>  	 * Currently: 46 entries, 390 bytes
> > >>>>>  	 */
> > >>>>> -	staticMetadata_ = allocate_camera_metadata(50, 500);
> > >>>>> +	staticMetadata_ = new CameraMetadata(50, 500);
> > >>>>> +	if (!staticMetadata_->isValid()) {
> > >>>>> +		LOG(HAL, Error) << "Failed to allocate static metadata";
> > >>>>> +		delete staticMetadata_;
> > >>>>> +		staticMetadata_ = nullptr;
> > >>>>> +		return nullptr;
> > >>>>
> > >>>> Empty line before return?
> > >>>
> > >>> I don't mind either way, but I haven't added one as the delete,
> > >>> assignment to nullptr and return nullptr are logically grouped in my
> > >>> opinion. Feel free to add a blank line if you prefer.
> > >>
> > >> Ok, if this was intentional let's keep it the way it is.
> > >>
> > >>>>> +	}
> > >>>>>
> > >>>>>  	/* Color correction static metadata. */
> > >>>>>  	std::vector<uint8_t> aberrationModes = {
> > >>>>>  		ANDROID_COLOR_CORRECTION_ABERRATION_MODE_OFF,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES,
> > >>>>> -			aberrationModes.data(), aberrationModes.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES,
> > >>>>> +				  aberrationModes.data(),
> > >>>>> +				  aberrationModes.size());
> > >>>>>
> > >>>>>  	/* Control static metadata. */
> > >>>>>  	std::vector<uint8_t> aeAvailableAntiBandingModes = {
> > >>>>> @@ -150,294 +151,228 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> > >>>>>  		ANDROID_CONTROL_AE_ANTIBANDING_MODE_60HZ,
> > >>>>>  		ANDROID_CONTROL_AE_ANTIBANDING_MODE_AUTO,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES,
> > >>>>> -			aeAvailableAntiBandingModes.data(),
> > >>>>> -			aeAvailableAntiBandingModes.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES,
> > >>>>> +				  aeAvailableAntiBandingModes.data(),
> > >>>>> +				  aeAvailableAntiBandingModes.size());
> > >>>>>
> > >>>>>  	std::vector<uint8_t> aeAvailableModes = {
> > >>>>>  		ANDROID_CONTROL_AE_MODE_ON,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_CONTROL_AE_AVAILABLE_MODES,
> > >>>>> -			aeAvailableModes.data(), aeAvailableModes.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_MODES,
> > >>>>> +				  aeAvailableModes.data(),
> > >>>>> +				  aeAvailableModes.size());
> > >>>>>
> > >>>>>  	std::vector<int32_t> availableAeFpsTarget = {
> > >>>>>  		15, 30,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES,
> > >>>>> -			availableAeFpsTarget.data(),
> > >>>>> -			availableAeFpsTarget.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES,
> > >>>>> +				  availableAeFpsTarget.data(),
> > >>>>> +				  availableAeFpsTarget.size());
> > >>>>>
> > >>>>>  	std::vector<int32_t> aeCompensationRange = {
> > >>>>>  		0, 0,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_CONTROL_AE_COMPENSATION_RANGE,
> > >>>>> -			aeCompensationRange.data(),
> > >>>>> -			aeCompensationRange.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_COMPENSATION_RANGE,
> > >>>>> +				  aeCompensationRange.data(),
> > >>>>> +				  aeCompensationRange.size());
> > >>>>>
> > >>>>>  	const camera_metadata_rational_t aeCompensationStep[] = {
> > >>>>>  		{ 0, 1 }
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_CONTROL_AE_COMPENSATION_STEP,
> > >>>>> -			aeCompensationStep, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_COMPENSATION_STEP,
> > >>>>> +				  aeCompensationStep, 1);
> > >>>>>
> > >>>>>  	std::vector<uint8_t> availableAfModes = {
> > >>>>>  		ANDROID_CONTROL_AF_MODE_OFF,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_CONTROL_AF_AVAILABLE_MODES,
> > >>>>> -			availableAfModes.data(), availableAfModes.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AF_AVAILABLE_MODES,
> > >>>>> +				  availableAfModes.data(),
> > >>>>> +				  availableAfModes.size());
> > >>>>>
> > >>>>>  	std::vector<uint8_t> availableEffects = {
> > >>>>>  		ANDROID_CONTROL_EFFECT_MODE_OFF,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_CONTROL_AVAILABLE_EFFECTS,
> > >>>>> -			availableEffects.data(), availableEffects.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_EFFECTS,
> > >>>>> +				  availableEffects.data(),
> > >>>>> +				  availableEffects.size());
> > >>>>>
> > >>>>>  	std::vector<uint8_t> availableSceneModes = {
> > >>>>>  		ANDROID_CONTROL_SCENE_MODE_DISABLED,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_CONTROL_AVAILABLE_SCENE_MODES,
> > >>>>> -			availableSceneModes.data(), availableSceneModes.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_SCENE_MODES,
> > >>>>> +				  availableSceneModes.data(),
> > >>>>> +				  availableSceneModes.size());
> > >>>>>
> > >>>>>  	std::vector<uint8_t> availableStabilizationModes = {
> > >>>>>  		ANDROID_CONTROL_VIDEO_STABILIZATION_MODE_OFF,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES,
> > >>>>> -			availableStabilizationModes.data(),
> > >>>>> -			availableStabilizationModes.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES,
> > >>>>> +				  availableStabilizationModes.data(),
> > >>>>> +				  availableStabilizationModes.size());
> > >>>>>
> > >>>>>  	std::vector<uint8_t> availableAwbModes = {
> > >>>>>  		ANDROID_CONTROL_AWB_MODE_OFF,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_CONTROL_AWB_AVAILABLE_MODES,
> > >>>>> -			availableAwbModes.data(), availableAwbModes.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AWB_AVAILABLE_MODES,
> > >>>>> +				  availableAwbModes.data(),
> > >>>>> +				  availableAwbModes.size());
> > >>>>>
> > >>>>>  	std::vector<int32_t> availableMaxRegions = {
> > >>>>>  		0, 0, 0,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_CONTROL_MAX_REGIONS,
> > >>>>> -			availableMaxRegions.data(), availableMaxRegions.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_MAX_REGIONS,
> > >>>>> +				  availableMaxRegions.data(),
> > >>>>> +				  availableMaxRegions.size());
> > >>>>>
> > >>>>>  	std::vector<uint8_t> sceneModesOverride = {
> > >>>>>  		ANDROID_CONTROL_AE_MODE_ON,
> > >>>>>  		ANDROID_CONTROL_AWB_MODE_AUTO,
> > >>>>>  		ANDROID_CONTROL_AF_MODE_AUTO,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_CONTROL_SCENE_MODE_OVERRIDES,
> > >>>>> -			sceneModesOverride.data(), sceneModesOverride.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_SCENE_MODE_OVERRIDES,
> > >>>>> +				  sceneModesOverride.data(),
> > >>>>> +				  sceneModesOverride.size());
> > >>>>>
> > >>>>>  	uint8_t aeLockAvailable = ANDROID_CONTROL_AE_LOCK_AVAILABLE_FALSE;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_CONTROL_AE_LOCK_AVAILABLE,
> > >>>>> -			&aeLockAvailable, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AE_LOCK_AVAILABLE,
> > >>>>> +				  &aeLockAvailable, 1);
> > >>>>>
> > >>>>>  	uint8_t awbLockAvailable = ANDROID_CONTROL_AWB_LOCK_AVAILABLE_FALSE;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
> > >>>>> -			&awbLockAvailable, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
> > >>>>> +				  &awbLockAvailable, 1);
> > >>>>>
> > >>>>>  	char availableControlModes = ANDROID_CONTROL_MODE_AUTO;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_CONTROL_AVAILABLE_MODES,
> > >>>>> -			&availableControlModes, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_MODES,
> > >>>>> +				  &availableControlModes, 1);
> > >>>>>
> > >>>>>  	/* JPEG static metadata. */
> > >>>>>  	std::vector<int32_t> availableThumbnailSizes = {
> > >>>>>  		0, 0,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
> > >>>>> -			availableThumbnailSizes.data(),
> > >>>>> -			availableThumbnailSizes.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
> > >>>>> +				  availableThumbnailSizes.data(),
> > >>>>> +				  availableThumbnailSizes.size());
> > >>>>>
> > >>>>>  	/* Sensor static metadata. */
> > >>>>>  	int32_t pixelArraySize[] = {
> > >>>>>  		2592, 1944,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -				ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
> > >>>>> -				&pixelArraySize, 2);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
> > >>>>> +				  &pixelArraySize, 2);
> > >>>>>
> > >>>>>  	int32_t sensorSizes[] = {
> > >>>>>  		0, 0, 2560, 1920,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -				ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
> > >>>>> -				&sensorSizes, 4);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
> > >>>>> +				  &sensorSizes, 4);
> > >>>>>
> > >>>>>  	int32_t sensitivityRange[] = {
> > >>>>>  		32, 2400,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -				ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
> > >>>>> -				&sensitivityRange, 2);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
> > >>>>> +				  &sensitivityRange, 2);
> > >>>>>
> > >>>>>  	uint16_t filterArr = ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT_GRBG;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -				ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
> > >>>>> -				&filterArr, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
> > >>>>> +				  &filterArr, 1);
> > >>>>>
> > >>>>>  	int64_t exposureTimeRange[] = {
> > >>>>>  		100000, 200000000,
> > >>>>>  	};
> > >>>>
> > >>>> I've been thinking for a while to stabilize on the use of std::vector in
> > >>>> place of arrays, so e can always use .data() and .size() and have
> > >>>> guaranteed we should only change the declaration and not the
> > >>>> parameters to the addEntry() operation.
> > >>>>
> > >>>> This might be a good time to do so. What do you think?
> > >>>
> > >>> I've thought about it, and constructing a vector is a bit costly
> > >>> compared to arrays. I'd rather used std::array<>, but that requires
> > >>> specifying the size explicitly :-S I've been thinking about overloading
> > >>> the addEntry() method, in order to be able to write
> > >>>
> > >>> 	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> > >>> 				  { 100000, 200000000 });
> > >>>
> > >>> I'm not sure if that will be possible as we need to handle different
> > >>> data types, but I think it's worth a try. Other overloaded methods
> > >>> should also be added for the arrays of a single element:
> > >>>
> > >>> 	staticMetadata_->addEntry(ANDROID_SENSOR_ORIENTATION, 0);
> > >>>
> > >>> I would prefer handling the standardisation of vector vs. array in a
> > >>> separate patch, when dealing with overloaded versions of addEntry(), as
> > >>> this patch is big enough already.
> > >>
> > >> Agreed
> > >>
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -				ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> > >>>>> -				&exposureTimeRange, 2);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
> > >>>>> +				  &exposureTimeRange, 2);
> > >>>>>
> > >>>>>  	int32_t orientation = 0;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -				ANDROID_SENSOR_ORIENTATION,
> > >>>>> -				&orientation, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_ORIENTATION,
> > >>>>> +				  &orientation, 1);
> > >>>>
> > >>>> Fits in 1 line
> > >>>
> > >>> I've kept it on two lines to use similar constructs through the whole
> > >>> function, but I don't mind much, so please feel free to change it if you
> > >>> prefer.
> > >>
> > >> If it was intentional, let's keep it the way it is
> > >>
> > >>>>>
> > >>>>>  	std::vector<int32_t> testPatterModes = {
> > >>>>>  		ANDROID_SENSOR_TEST_PATTERN_MODE_OFF,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -				ANDROID_SENSOR_AVAILABLE_TEST_PATTERN_MODES,
> > >>>>> -				testPatterModes.data(), testPatterModes.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_AVAILABLE_TEST_PATTERN_MODES,
> > >>>>> +				  testPatterModes.data(),
> > >>>>> +				  testPatterModes.size());
> > >>>>>
> > >>>>>  	std::vector<float> physicalSize = {
> > >>>>>  		2592, 1944,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -				ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
> > >>>>> -				physicalSize.data(), physicalSize.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
> > >>>>> +				  physicalSize.data(),
> > >>>>> +				  physicalSize.size());
> > >>>>
> > >>>> Fits in 1 line
> > >>>>
> > >>>>>
> > >>>>>  	uint8_t timestampSource = ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE_UNKNOWN;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE,
> > >>>>> -			&timestampSource, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE,
> > >>>>> +				  &timestampSource, 1);
> > >>>>>
> > >>>>>  	/* Statistics static metadata. */
> > >>>>>  	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
> > >>>>> -			&faceDetectMode, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
> > >>>>> +				  &faceDetectMode, 1);
> > >>>>>
> > >>>>>  	int32_t maxFaceCount = 0;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
> > >>>>> -			&maxFaceCount, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
> > >>>>> +				  &maxFaceCount, 1);
> > >>>>>
> > >>>>>  	/* Sync static metadata. */
> > >>>>>  	int32_t maxLatency = ANDROID_SYNC_MAX_LATENCY_UNKNOWN;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_SYNC_MAX_LATENCY, &maxLatency, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_SYNC_MAX_LATENCY, &maxLatency, 1);
> > >>>>>
> > >>>>>  	/* Flash static metadata. */
> > >>>>>  	char flashAvailable = ANDROID_FLASH_INFO_AVAILABLE_FALSE;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_FLASH_INFO_AVAILABLE,
> > >>>>> -			&flashAvailable, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_FLASH_INFO_AVAILABLE,
> > >>>>> +				  &flashAvailable, 1);
> > >>>>>
> > >>>>>  	/* Lens static metadata. */
> > >>>>>  	std::vector<float> lensApertures = {
> > >>>>>  		2.53 / 100,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -				ANDROID_LENS_INFO_AVAILABLE_APERTURES,
> > >>>>> -				lensApertures.data(), lensApertures.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_APERTURES,
> > >>>>> +				  lensApertures.data(),
> > >>>>> +				  lensApertures.size());
> > >>>>>
> > >>>>>  	uint8_t lensFacing = ANDROID_LENS_FACING_FRONT;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -				ANDROID_LENS_FACING, &lensFacing, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_LENS_FACING, &lensFacing, 1);
> > >>>>>
> > >>>>>  	std::vector<float> lensFocalLenghts = {
> > >>>>>  		1,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -				ANDROID_LENS_INFO_AVAILABLE_FOCAL_LENGTHS,
> > >>>>> -				lensFocalLenghts.data(),
> > >>>>> -				lensFocalLenghts.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_FOCAL_LENGTHS,
> > >>>>> +				  lensFocalLenghts.data(),
> > >>>>> +				  lensFocalLenghts.size());
> > >>>>>
> > >>>>>  	std::vector<uint8_t> opticalStabilizations = {
> > >>>>>  		ANDROID_LENS_OPTICAL_STABILIZATION_MODE_OFF,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -				ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
> > >>>>> -				opticalStabilizations.data(),
> > >>>>> -				opticalStabilizations.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
> > >>>>> +				  opticalStabilizations.data(),
> > >>>>> +				  opticalStabilizations.size());
> > >>>>>
> > >>>>>  	float hypeFocalDistance = 0;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -				ANDROID_LENS_INFO_HYPERFOCAL_DISTANCE,
> > >>>>> -				&hypeFocalDistance, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_HYPERFOCAL_DISTANCE,
> > >>>>> +				  &hypeFocalDistance, 1);
> > >>>>>
> > >>>>>  	float minFocusDistance = 0;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -				ANDROID_LENS_INFO_MINIMUM_FOCUS_DISTANCE,
> > >>>>> -				&minFocusDistance, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_LENS_INFO_MINIMUM_FOCUS_DISTANCE,
> > >>>>> +				  &minFocusDistance, 1);
> > >>>>>
> > >>>>>  	/* Noise reduction modes. */
> > >>>>>  	uint8_t noiseReductionModes = ANDROID_NOISE_REDUCTION_MODE_OFF;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -				ANDROID_NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES,
> > >>>>> -				&noiseReductionModes, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES,
> > >>>>> +				  &noiseReductionModes, 1);
> > >>>>>
> > >>>>>  	/* Scaler static metadata. */
> > >>>>>  	float maxDigitalZoom = 1;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_SCALER_AVAILABLE_MAX_DIGITAL_ZOOM,
> > >>>>> -			&maxDigitalZoom, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_MAX_DIGITAL_ZOOM,
> > >>>>> +				  &maxDigitalZoom, 1);
> > >>>>>
> > >>>>>  	std::vector<uint32_t> availableStreamFormats = {
> > >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB,
> > >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_YCbCr_420_888,
> > >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_SCALER_AVAILABLE_FORMATS,
> > >>>>> -			availableStreamFormats.data(),
> > >>>>> -			availableStreamFormats.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_FORMATS,
> > >>>>> +				  availableStreamFormats.data(),
> > >>>>> +				  availableStreamFormats.size());
> > >>>>>
> > >>>>>  	std::vector<uint32_t> availableStreamConfigurations = {
> > >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920,
> > >>>>> @@ -447,65 +382,57 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> > >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED, 2560, 1920,
> > >>>>>  		ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS_OUTPUT,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS,
> > >>>>> -			availableStreamConfigurations.data(),
> > >>>>> -			availableStreamConfigurations.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS,
> > >>>>> +				  availableStreamConfigurations.data(),
> > >>>>> +				  availableStreamConfigurations.size());
> > >>>>>
> > >>>>>  	std::vector<int64_t> availableStallDurations = {
> > >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920, 33333333,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_SCALER_AVAILABLE_STALL_DURATIONS,
> > >>>>> -			availableStallDurations.data(),
> > >>>>> -			availableStallDurations.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_STALL_DURATIONS,
> > >>>>> +				  availableStallDurations.data(),
> > >>>>> +				  availableStallDurations.size());
> > >>>>>
> > >>>>>  	std::vector<int64_t> minFrameDurations = {
> > >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920, 33333333,
> > >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED, 2560, 1920, 33333333,
> > >>>>>  		ANDROID_SCALER_AVAILABLE_FORMATS_YCbCr_420_888, 2560, 1920, 33333333,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_SCALER_AVAILABLE_MIN_FRAME_DURATIONS,
> > >>>>> -			minFrameDurations.data(), minFrameDurations.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_MIN_FRAME_DURATIONS,
> > >>>>> +				  minFrameDurations.data(),
> > >>>>> +				  minFrameDurations.size());
> > >>>>>
> > >>>>>  	uint8_t croppingType = ANDROID_SCALER_CROPPING_TYPE_CENTER_ONLY;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_SCALER_CROPPING_TYPE, &croppingType, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_SCALER_CROPPING_TYPE, &croppingType, 1);
> > >>>>>
> > >>>>>  	/* Info static metadata. */
> > >>>>>  	uint8_t supportedHWLevel = ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL,
> > >>>>> -			&supportedHWLevel, 1);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL,
> > >>>>> +				  &supportedHWLevel, 1);
> > >>>>>
> > >>>>>  	/* Request static metadata. */
> > >>>>>  	int32_t partialResultCount = 1;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_REQUEST_PARTIAL_RESULT_COUNT,
> > >>>>> -			&partialResultCount, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_REQUEST_PARTIAL_RESULT_COUNT,
> > >>>>> +				  &partialResultCount, 1);
> > >>>>>
> > >>>>>  	uint8_t maxPipelineDepth = 2;
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_REQUEST_PIPELINE_MAX_DEPTH,
> > >>>>> -			&maxPipelineDepth, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_REQUEST_PIPELINE_MAX_DEPTH,
> > >>>>> +				  &maxPipelineDepth, 1);
> > >>>>>
> > >>>>>  	std::vector<uint8_t> availableCapabilities = {
> > >>>>>  		ANDROID_REQUEST_AVAILABLE_CAPABILITIES_BACKWARD_COMPATIBLE,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(staticMetadata_,
> > >>>>> -			ANDROID_REQUEST_AVAILABLE_CAPABILITIES,
> > >>>>> -			availableCapabilities.data(),
> > >>>>> -			availableCapabilities.size());
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	staticMetadata_->addEntry(ANDROID_REQUEST_AVAILABLE_CAPABILITIES,
> > >>>>> +				  availableCapabilities.data(),
> > >>>>> +				  availableCapabilities.size());
> > >>>>> +
> > >>>>> +	if (!staticMetadata_->isValid()) {
> > >>>>> +		delete staticMetadata_;
> > >>>>> +		staticMetadata_ = nullptr;
> > >>>>> +		return nullptr;
> > >>>>> +	}
> > >>>>>
> > >>>>> -	return staticMetadata_;
> > >>>>> +	return staticMetadata_->get();
> > >>>>>  }
> > >>>>>
> > >>>>>  /*
> > >>>>> @@ -513,8 +440,6 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
> > >>>>>   */
> > >>>>>  const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
> > >>>>>  {
> > >>>>> -	int ret;
> > >>>>> -
> > >>>>>  	/*
> > >>>>>  	 * \todo Inspect type and pick the right metadata pack.
> > >>>>>  	 * As of now just use a single one for all templates.
> > >>>>> @@ -545,89 +470,73 @@ const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
> > >>>>>  	}
> > >>>>>
> > >>>>>  	if (requestTemplate_)
> > >>>>> -		return requestTemplate_;
> > >>>>> +		return requestTemplate_->get();
> > >>>>>
> > >>>>>  	/*
> > >>>>>  	 * \todo Keep this in sync with the actual number of entries.
> > >>>>>  	 * Currently: 12 entries, 15 bytes
> > >>>>>  	 */
> > >>>>> -	requestTemplate_ = allocate_camera_metadata(15, 20);
> > >>>>> +	requestTemplate_ = new CameraMetadata(15, 20);
> > >>>>>  	if (!requestTemplate_) {
> > >>>>>  		LOG(HAL, Error) << "Failed to allocate template metadata";
> > >>>>> +		delete requestTemplate_;
> > >>>>> +		requestTemplate_ = nullptr;
> > >>>>
> > >>>> Empty line before return ?
> > >>>>
> > >>>>>  		return nullptr;
> > >>>>>  	}
> > >>>>>
> > >>>>>  	uint8_t aeMode = ANDROID_CONTROL_AE_MODE_ON;
> > >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>>>> -			ANDROID_CONTROL_AE_MODE,
> > >>>>> -			&aeMode, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_MODE,
> > >>>>> +				   &aeMode, 1);
> > >>>>
> > >>>> This and many others entries here and below fit in 1 line.
> > >>>>
> > >>>>>
> > >>>>>  	int32_t aeExposureCompensation = 0;
> > >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>>>> -			ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION,
> > >>>>> -			&aeExposureCompensation, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION,
> > >>>>> +				   &aeExposureCompensation, 1);
> > >>>>>
> > >>>>>  	uint8_t aePrecaptureTrigger = ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER_IDLE;
> > >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>>>> -			ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER,
> > >>>>> -			&aePrecaptureTrigger, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER,
> > >>>>> +				   &aePrecaptureTrigger, 1);
> > >>>>>
> > >>>>>  	uint8_t aeLock = ANDROID_CONTROL_AE_LOCK_OFF;
> > >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>>>> -			ANDROID_CONTROL_AE_LOCK,
> > >>>>> -			&aeLock, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AE_LOCK,
> > >>>>> +				   &aeLock, 1);
> > >>>>>
> > >>>>>  	uint8_t afTrigger = ANDROID_CONTROL_AF_TRIGGER_IDLE;
> > >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>>>> -			ANDROID_CONTROL_AF_TRIGGER,
> > >>>>> -			&afTrigger, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AF_TRIGGER,
> > >>>>> +				   &afTrigger, 1);
> > >>>>>
> > >>>>>  	uint8_t awbMode = ANDROID_CONTROL_AWB_MODE_AUTO;
> > >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>>>> -			ANDROID_CONTROL_AWB_MODE,
> > >>>>> -			&awbMode, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AWB_MODE,
> > >>>>> +				   &awbMode, 1);
> > >>>>>
> > >>>>>  	uint8_t awbLock = ANDROID_CONTROL_AWB_LOCK_OFF;
> > >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>>>> -			ANDROID_CONTROL_AWB_LOCK,
> > >>>>> -			&awbLock, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	requestTemplate_->addEntry(ANDROID_CONTROL_AWB_LOCK,
> > >>>>> +				   &awbLock, 1);
> > >>>>>
> > >>>>>  	uint8_t flashMode = ANDROID_FLASH_MODE_OFF;
> > >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>>>> -			ANDROID_FLASH_MODE,
> > >>>>> -			&flashMode, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	requestTemplate_->addEntry(ANDROID_FLASH_MODE,
> > >>>>> +				   &flashMode, 1);
> > >>>>>
> > >>>>>  	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
> > >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>>>> -			ANDROID_STATISTICS_FACE_DETECT_MODE,
> > >>>>> -			&faceDetectMode, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	requestTemplate_->addEntry(ANDROID_STATISTICS_FACE_DETECT_MODE,
> > >>>>> +				   &faceDetectMode, 1);
> > >>>>>
> > >>>>>  	uint8_t noiseReduction = ANDROID_NOISE_REDUCTION_MODE_OFF;
> > >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>>>> -			ANDROID_NOISE_REDUCTION_MODE, &noiseReduction, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	requestTemplate_->addEntry(ANDROID_NOISE_REDUCTION_MODE,
> > >>>>> +				   &noiseReduction, 1);
> > >>>>>
> > >>>>>  	uint8_t aberrationMode = ANDROID_COLOR_CORRECTION_ABERRATION_MODE_OFF;
> > >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>>>> -			ANDROID_COLOR_CORRECTION_ABERRATION_MODE,
> > >>>>> -			&aberrationMode, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	requestTemplate_->addEntry(ANDROID_COLOR_CORRECTION_ABERRATION_MODE,
> > >>>>> +				   &aberrationMode, 1);
> > >>>>> +
> > >>>>> +	requestTemplate_->addEntry(ANDROID_CONTROL_CAPTURE_INTENT,
> > >>>>> +				   &captureIntent, 1);
> > >>>>>
> > >>>>> -	ret = add_camera_metadata_entry(requestTemplate_,
> > >>>>> -			ANDROID_CONTROL_CAPTURE_INTENT,
> > >>>>> -			&captureIntent, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	if (!requestTemplate_->isValid()) {
> > >>>>> +		delete requestTemplate_;
> > >>>>> +		requestTemplate_ = nullptr;
> > >>>>
> > >>>> You should return nullptr here, otherwise the below requestTemplate_->get();
> > >>>> will de-reference a nullptr.
> > >>>
> > >>> Absolutely, my bad.
> > >>>
> > >>>>> +	}
> > >>>>>
> > >>>>> -	return requestTemplate_;
> > >>>>> +	return requestTemplate_->get();
> > >>>>>  }
> > >>>>>
> > >>>>>  /*
> > >>>>> @@ -799,7 +708,7 @@ void CameraDevice::requestComplete(Request *request,
> > >>>>>  {
> > >>>>>  	Buffer *libcameraBuffer = buffers.begin()->second;
> > >>>>>  	camera3_buffer_status status = CAMERA3_BUFFER_STATUS_OK;
> > >>>>> -	camera_metadata_t *resultMetadata = nullptr;
> > >>>>> +	std::unique_ptr<CameraMetadata> resultMetadata;
> > >>>>>
> > >>>>>  	if (request->status() != Request::RequestComplete) {
> > >>>>>  		LOG(HAL, Error) << "Request not succesfully completed: "
> > >>>>> @@ -837,16 +746,12 @@ void CameraDevice::requestComplete(Request *request,
> > >>>>>  		captureResult.partial_result = 1;
> > >>>>>  		resultMetadata = getResultMetadata(descriptor->frameNumber,
> > >>>>>  						   libcameraBuffer->timestamp());
> > >>>>> -		captureResult.result = resultMetadata;
> > >>>>> +		captureResult.result = resultMetadata->get();
> > >>>>>  	}
> > >>>>>
> > >>>>>  	callbacks_->process_capture_result(callbacks_, &captureResult);
> > >>>>>
> > >>>>>  	delete descriptor;
> > >>>>> -	if (resultMetadata)
> > >>>>> -		free_camera_metadata(resultMetadata);
> > >>>>> -
> > >>>>> -	return;
> > >>>>>  }
> > >>>>>
> > >>>>>  void CameraDevice::notifyShutter(uint32_t frameNumber, uint64_t timestamp)
> > >>>>> @@ -875,89 +780,63 @@ void CameraDevice::notifyError(uint32_t frameNumber, camera3_stream_t *stream)
> > >>>>>  /*
> > >>>>>   * Produce a set of fixed result metadata.
> > >>>>>   */
> > >>>>> -camera_metadata_t *CameraDevice::getResultMetadata(int frame_number,
> > >>>>> -						   int64_t timestamp)
> > >>>>> +std::unique_ptr<CameraMetadata> CameraDevice::getResultMetadata(int frame_number,
> > >>>>
> > >>>> Not a fan of smart pointers, you know already. How does this work?
> > >>>> Because the compiler applies copy-elision or because of the move
> > >>>> semantic applied on the return value?
> > >>>
> > >>> std::unique_ptr<> has an operator= that takes an rvalue reference to
> > >>> another std::unique_ptr<>, and uses move semantic. As explained in
> > >>> https://en.cppreference.com/w/cpp/language/value_category, an rvalue is
> > >>> either a prvalue or an xvalue, and a prvalue can be "a function call or
> > >>> an overloaded operator expression, whose return type is non-reference".
> > >>> As far as I can tell, that's why we don't need an std::move() in the
> > >>> caller.
> > >>
> > >> I see.. This seems to suggest both RVO and move semantic can play a
> > >> role https://stackoverflow.com/a/46571941
> > >>
> > >> Ah, c++
> > >>
> > >>>> difficult to follow in my opinion.
> > >>>
> > >>> I think we should standardise as much as possible on std::unique_ptr<>
> > >>> when passing ownership of a returned pointer. That's documented in
> > >>> Documentation/coding-style.rst.
> > >>
> > >> Ack, let's keep it the way it is then.
> > >>
> > >>>>> +								int64_t timestamp)
> > >>>>>  {
> > >>>>> -	int ret;
> > >>>>> -
> > >>>>>  	/*
> > >>>>>  	 * \todo Keep this in sync with the actual number of entries.
> > >>>>>  	 * Currently: 13 entries, 36 bytes
> > >>>>>  	 */
> > >>>>> -	camera_metadata_t *resultMetadata = allocate_camera_metadata(15, 50);
> > >>>>> +	std::unique_ptr<CameraMetadata> resultMetadata =
> > >>>>> +		utils::make_unique<CameraMetadata>(15, 50);
> > >>>>> +	if (!resultMetadata->isValid()) {
> > >>>>> +		LOG(HAL, Error) << "Failed to allocate static metadata";
> > >>>>> +		return nullptr;
> > >>>>> +	}
> > >>>>>
> > >>>>>  	const uint8_t ae_state = ANDROID_CONTROL_AE_STATE_CONVERGED;
> > >>>>> -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AE_STATE,
> > >>>>> -					&ae_state, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	resultMetadata->addEntry(ANDROID_CONTROL_AE_STATE, &ae_state, 1);
> > >>>>>
> > >>>>>  	const uint8_t ae_lock = ANDROID_CONTROL_AE_LOCK_OFF;
> > >>>>> -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AE_LOCK,
> > >>>>> -					&ae_lock, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	resultMetadata->addEntry(ANDROID_CONTROL_AE_LOCK, &ae_lock, 1);
> > >>>>>
> > >>>>>  	uint8_t af_state = ANDROID_CONTROL_AF_STATE_INACTIVE;
> > >>>>> -	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AF_STATE,
> > >>>>> -					&af_state, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	resultMetadata->addEntry(ANDROID_CONTROL_AF_STATE, &af_state, 1);
> > >>>>>
> > >>>>>  	const uint8_t awb_state = ANDROID_CONTROL_AWB_STATE_CONVERGED;
> > >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>>>> -					ANDROID_CONTROL_AWB_STATE,
> > >>>>> -					&awb_state, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	resultMetadata->addEntry(ANDROID_CONTROL_AWB_STATE, &awb_state, 1);
> > >>>>>
> > >>>>>  	const uint8_t awb_lock = ANDROID_CONTROL_AWB_LOCK_OFF;
> > >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>>>> -					ANDROID_CONTROL_AWB_LOCK,
> > >>>>> -					&awb_lock, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	resultMetadata->addEntry(ANDROID_CONTROL_AWB_LOCK, &awb_lock, 1);
> > >>>>>
> > >>>>>  	const uint8_t lens_state = ANDROID_LENS_STATE_STATIONARY;
> > >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>>>> -					ANDROID_LENS_STATE,
> > >>>>> -					&lens_state, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	resultMetadata->addEntry(ANDROID_LENS_STATE, &lens_state, 1);
> > >>>>>
> > >>>>>  	int32_t sensorSizes[] = {
> > >>>>>  		0, 0, 2560, 1920,
> > >>>>>  	};
> > >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>>>> -					ANDROID_SCALER_CROP_REGION,
> > >>>>> -					sensorSizes, 4);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	resultMetadata->addEntry(ANDROID_SCALER_CROP_REGION, sensorSizes, 4);
> > >>>>>
> > >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>>>> -					ANDROID_SENSOR_TIMESTAMP,
> > >>>>> -					&timestamp, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	resultMetadata->addEntry(ANDROID_SENSOR_TIMESTAMP, &timestamp, 1);
> > >>>>>
> > >>>>>  	/* 33.3 msec */
> > >>>>>  	const int64_t rolling_shutter_skew = 33300000;
> > >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>>>> -					ANDROID_SENSOR_ROLLING_SHUTTER_SKEW,
> > >>>>> -					&rolling_shutter_skew, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	resultMetadata->addEntry(ANDROID_SENSOR_ROLLING_SHUTTER_SKEW,
> > >>>>> +				 &rolling_shutter_skew, 1);
> > >>>>>
> > >>>>>  	/* 16.6 msec */
> > >>>>>  	const int64_t exposure_time = 16600000;
> > >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>>>> -					ANDROID_SENSOR_EXPOSURE_TIME,
> > >>>>> -					&exposure_time, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	resultMetadata->addEntry(ANDROID_SENSOR_EXPOSURE_TIME,
> > >>>>> +				 &exposure_time, 1);
> > >>>>>
> > >>>>>  	const uint8_t lens_shading_map_mode =
> > >>>>>  				ANDROID_STATISTICS_LENS_SHADING_MAP_MODE_OFF;
> > >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>>>> -					ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
> > >>>>> -					&lens_shading_map_mode, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	resultMetadata->addEntry(ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
> > >>>>> +				 &lens_shading_map_mode, 1);
> > >>>>>
> > >>>>>  	const uint8_t scene_flicker = ANDROID_STATISTICS_SCENE_FLICKER_NONE;
> > >>>>> -	ret = add_camera_metadata_entry(resultMetadata,
> > >>>>> -					ANDROID_STATISTICS_SCENE_FLICKER,
> > >>>>> -					&scene_flicker, 1);
> > >>>>> -	METADATA_ASSERT(ret);
> > >>>>> +	resultMetadata->addEntry(ANDROID_STATISTICS_SCENE_FLICKER,
> > >>>>> +				 &scene_flicker, 1);
> > >>>>
> > >>>> Shouldn't you check if the metadata pack is valid ?
> > >>>
> > >>> Good point. Should we check here or in the caller ? As the caller would
> > >>> then need a nullptr check I'm tempted to do so in the caller. Actually,
> > >>> without a change to the code, the caller will operate correctly I
> > >>> believe
> > >>>
> > >>>                 resultMetadata = getResultMetadata(descriptor->frameNumber,
> > >>>                                                    libcameraBuffer->timestamp());
> > >>>                 captureResult.result = resultMetadata->get();
> > >>>
> > >>> which will set captureResult.result to nullptr if resultMetadata is not
> > >>> valid.
> > >>
> > >> Yeah, but in that case we should notify an error back to the stack.
> > >
> > > That makes sense. It should be a faily uncommon case though, is it would
> > > be the result of a bug in our code, but bugs happen. I wonder what the
> > > proper error recovery would be in that case.
> > >
> > >> What about:
> > >>
> > >>         resultMetadata = getResultMetadata(descriptor->frameNumber,
> > >>                                            libcameraBuffer->timestamp());
> > >> 	if (status == CAMERA3_BUFFER_STATUS_ERROR || !resultMetadata) {
> > >> 		/* \todo Improve error handling. */
> > >> 		notifyError(descriptor->frameNumber,
> > >> 			    descriptor->buffers[0].stream);
> > >> 	} else {
> > >> 		notifyShutter(descriptor->frameNumber,
> > >> 			      libcameraBuffer->timestamp());
> > >>
> > >> 		captureResult.partial_result = 1;
> > >> 		captureResult.result = resultMetadata->get();
> > >> 	}
> > >>
> > >> The drawback is that we're generating the result metadata even if
> > >> status is set to CAMERA3_BUFFER_STATUS_ERROR.
> > >
> > > That I don't think we should do, as I expect the result metadata
> > > generation will not be possible in case of CAMERA3_BUFFER_STATUS_ERROR
> > > when we'll stop generating fake metadata.
> > >
> > > How about this ?
> > >
> > > 	if (status == CAMERA3_BUFFER_STATUS_OK) {
> > > 		notifyShutter(descriptor->frameNumber,
> > > 			      libcameraBuffer->timestamp());
> > >
> > > 		captureResult.partial_result = 1;
> > > 		resultMetadata = getResultMetadata(descriptor->frameNumber,
> > > 						   libcameraBuffer->timestamp());
> > > 		captureResult.result = resultMetadata->get();
> > > 	}
> > >
> > > 	if (status == CAMERA3_BUFFER_STATUS_ERROR || !captureResult.result) {
> > > 		/* \todo Improve error handling. */
> > > 		notifyError(descriptor->frameNumber,
> > > 			    descriptor->buffers[0].stream);
> > > 	}
> > >
> > > The last condition could be written if (!captureResult.result) as
> > > CAMERA3_BUFFER_STATUS_ERROR implies !captureResult.result, but I'd
> > > rather have both to make it explicit.
> >
> > The only difference I see here is that we send up a shutter event and
> > the if metadata generation fails we send back an error.
> >
> > In the previous version was either an error or the shutter
> > notification, not both.
> >
> > I can't tell if this makes any difference to the camera stack to be
> > honest.
>
> Neither can I, and this shouldn't happen in the first place :-) If you
> want to avoid it,
>

I have expanded the todo comment in v7 which I posted before this.
If no other comments on v7 I can take this in when applying, or keep
the version in v7 which doesn't seem so dangerous after all.



>  	if (status == CAMERA3_BUFFER_STATUS_OK) {
>  		captureResult.partial_result = 1;
>  		resultMetadata = getResultMetadata(descriptor->frameNumber,
>  						   libcameraBuffer->timestamp());
>  		captureResult.result = resultMetadata->get();
>  	}
>
>  	if (status == CAMERA3_BUFFER_STATUS_OK && captureResult.result) {
>  		notifyShutter(descriptor->frameNumber,
>  			      libcameraBuffer->timestamp());
> 	} else {
>  		/* \todo Improve error handling. */
>  		notifyError(descriptor->frameNumber,
>  			    descriptor->buffers[0].stream);
>  	}
>
> > >>>>>
> > >>>>>  	return resultMetadata;
> > >>>>>  }
> > >>>>> diff --git a/src/android/camera_device.h b/src/android/camera_device.h
> > >>>>> index 7897ba9dc5c7..65ba877a02ea 100644
> > >>>>> --- a/src/android/camera_device.h
> > >>>>> +++ b/src/android/camera_device.h
> > >>>>> @@ -19,13 +19,7 @@
> > >>>>>
> > >>>>>  #include "message.h"
> > >>>>>
> > >>>>> -#define METADATA_ASSERT(_r)		\
> > >>>>> -	do {				\
> > >>>>> -		if (!(_r)) break;	\
> > >>>>> -		LOG(HAL, Error) << "Error: " << __func__ << ":" << __LINE__; \
> > >>>>> -		return nullptr;		\
> > >>>>> -	} while(0);
> > >>>>> -
> > >>>>> +class CameraMetadata;
> > >>>>>  class ThreadRpc;
> > >>>>>
> > >>>>>  class CameraDevice : public libcamera::Object
> > >>>>> @@ -59,14 +53,15 @@ private:
> > >>>>>
> > >>>>>  	void notifyShutter(uint32_t frameNumber, uint64_t timestamp);
> > >>>>>  	void notifyError(uint32_t frameNumber, camera3_stream_t *stream);
> > >>>>> -	camera_metadata_t *getResultMetadata(int frame_number, int64_t timestamp);
> > >>>>> +	std::unique_ptr<CameraMetadata> getResultMetadata(int frame_number,
> > >>>>> +							  int64_t timestamp);
> > >>>>>
> > >>>>>  	bool running_;
> > >>>>>  	std::shared_ptr<libcamera::Camera> camera_;
> > >>>>>  	std::unique_ptr<libcamera::CameraConfiguration> config_;
> > >>>>>
> > >>>>> -	camera_metadata_t *staticMetadata_;
> > >>>>> -	camera_metadata_t *requestTemplate_;
> > >>>>> +	CameraMetadata *staticMetadata_;
> > >>>>> +	CameraMetadata *requestTemplate_;
> > >>>>>  	const camera3_callback_ops_t *callbacks_;
> > >>>>>  };
> > >>>>>
>
> --
> Regards,
>
> Laurent Pinchart

Patch

diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
index 5f8d19b9ef3d..475fa2404421 100644
--- a/src/android/camera_device.cpp
+++ b/src/android/camera_device.cpp
@@ -7,10 +7,10 @@ 
 
 #include "camera_device.h"
 
-#include <system/camera_metadata.h>
-
 #include "log.h"
+#include "utils.h"
 
+#include "camera_metadata.h"
 #include "thread_rpc.h"
 
 using namespace libcamera;
@@ -59,12 +59,10 @@  CameraDevice::CameraDevice(unsigned int id, const std::shared_ptr<Camera> &camer
 CameraDevice::~CameraDevice()
 {
 	if (staticMetadata_)
-		free_camera_metadata(staticMetadata_);
-	staticMetadata_ = nullptr;
+		delete staticMetadata_;
 
 	if (requestTemplate_)
-		free_camera_metadata(requestTemplate_);
-	requestTemplate_ = nullptr;
+		delete requestTemplate_;
 }
 
 /*
@@ -117,10 +115,8 @@  void CameraDevice::setCallbacks(const camera3_callback_ops_t *callbacks)
  */
 camera_metadata_t *CameraDevice::getStaticMetadata()
 {
-	int ret;
-
 	if (staticMetadata_)
-		return staticMetadata_;
+		return staticMetadata_->get();
 
 	/*
 	 * The here reported metadata are enough to implement a basic capture
@@ -132,16 +128,21 @@  camera_metadata_t *CameraDevice::getStaticMetadata()
 	 * \todo Keep this in sync with the actual number of entries.
 	 * Currently: 46 entries, 390 bytes
 	 */
-	staticMetadata_ = allocate_camera_metadata(50, 500);
+	staticMetadata_ = new CameraMetadata(50, 500);
+	if (!staticMetadata_->isValid()) {
+		LOG(HAL, Error) << "Failed to allocate static metadata";
+		delete staticMetadata_;
+		staticMetadata_ = nullptr;
+		return nullptr;
+	}
 
 	/* Color correction static metadata. */
 	std::vector<uint8_t> aberrationModes = {
 		ANDROID_COLOR_CORRECTION_ABERRATION_MODE_OFF,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES,
-			aberrationModes.data(), aberrationModes.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES,
+				  aberrationModes.data(),
+				  aberrationModes.size());
 
 	/* Control static metadata. */
 	std::vector<uint8_t> aeAvailableAntiBandingModes = {
@@ -150,294 +151,228 @@  camera_metadata_t *CameraDevice::getStaticMetadata()
 		ANDROID_CONTROL_AE_ANTIBANDING_MODE_60HZ,
 		ANDROID_CONTROL_AE_ANTIBANDING_MODE_AUTO,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES,
-			aeAvailableAntiBandingModes.data(),
-			aeAvailableAntiBandingModes.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES,
+				  aeAvailableAntiBandingModes.data(),
+				  aeAvailableAntiBandingModes.size());
 
 	std::vector<uint8_t> aeAvailableModes = {
 		ANDROID_CONTROL_AE_MODE_ON,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_CONTROL_AE_AVAILABLE_MODES,
-			aeAvailableModes.data(), aeAvailableModes.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_MODES,
+				  aeAvailableModes.data(),
+				  aeAvailableModes.size());
 
 	std::vector<int32_t> availableAeFpsTarget = {
 		15, 30,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES,
-			availableAeFpsTarget.data(),
-			availableAeFpsTarget.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES,
+				  availableAeFpsTarget.data(),
+				  availableAeFpsTarget.size());
 
 	std::vector<int32_t> aeCompensationRange = {
 		0, 0,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_CONTROL_AE_COMPENSATION_RANGE,
-			aeCompensationRange.data(),
-			aeCompensationRange.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_CONTROL_AE_COMPENSATION_RANGE,
+				  aeCompensationRange.data(),
+				  aeCompensationRange.size());
 
 	const camera_metadata_rational_t aeCompensationStep[] = {
 		{ 0, 1 }
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_CONTROL_AE_COMPENSATION_STEP,
-			aeCompensationStep, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_CONTROL_AE_COMPENSATION_STEP,
+				  aeCompensationStep, 1);
 
 	std::vector<uint8_t> availableAfModes = {
 		ANDROID_CONTROL_AF_MODE_OFF,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_CONTROL_AF_AVAILABLE_MODES,
-			availableAfModes.data(), availableAfModes.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_CONTROL_AF_AVAILABLE_MODES,
+				  availableAfModes.data(),
+				  availableAfModes.size());
 
 	std::vector<uint8_t> availableEffects = {
 		ANDROID_CONTROL_EFFECT_MODE_OFF,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_CONTROL_AVAILABLE_EFFECTS,
-			availableEffects.data(), availableEffects.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_EFFECTS,
+				  availableEffects.data(),
+				  availableEffects.size());
 
 	std::vector<uint8_t> availableSceneModes = {
 		ANDROID_CONTROL_SCENE_MODE_DISABLED,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_CONTROL_AVAILABLE_SCENE_MODES,
-			availableSceneModes.data(), availableSceneModes.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_SCENE_MODES,
+				  availableSceneModes.data(),
+				  availableSceneModes.size());
 
 	std::vector<uint8_t> availableStabilizationModes = {
 		ANDROID_CONTROL_VIDEO_STABILIZATION_MODE_OFF,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES,
-			availableStabilizationModes.data(),
-			availableStabilizationModes.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES,
+				  availableStabilizationModes.data(),
+				  availableStabilizationModes.size());
 
 	std::vector<uint8_t> availableAwbModes = {
 		ANDROID_CONTROL_AWB_MODE_OFF,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_CONTROL_AWB_AVAILABLE_MODES,
-			availableAwbModes.data(), availableAwbModes.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_CONTROL_AWB_AVAILABLE_MODES,
+				  availableAwbModes.data(),
+				  availableAwbModes.size());
 
 	std::vector<int32_t> availableMaxRegions = {
 		0, 0, 0,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_CONTROL_MAX_REGIONS,
-			availableMaxRegions.data(), availableMaxRegions.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_CONTROL_MAX_REGIONS,
+				  availableMaxRegions.data(),
+				  availableMaxRegions.size());
 
 	std::vector<uint8_t> sceneModesOverride = {
 		ANDROID_CONTROL_AE_MODE_ON,
 		ANDROID_CONTROL_AWB_MODE_AUTO,
 		ANDROID_CONTROL_AF_MODE_AUTO,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_CONTROL_SCENE_MODE_OVERRIDES,
-			sceneModesOverride.data(), sceneModesOverride.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_CONTROL_SCENE_MODE_OVERRIDES,
+				  sceneModesOverride.data(),
+				  sceneModesOverride.size());
 
 	uint8_t aeLockAvailable = ANDROID_CONTROL_AE_LOCK_AVAILABLE_FALSE;
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_CONTROL_AE_LOCK_AVAILABLE,
-			&aeLockAvailable, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_CONTROL_AE_LOCK_AVAILABLE,
+				  &aeLockAvailable, 1);
 
 	uint8_t awbLockAvailable = ANDROID_CONTROL_AWB_LOCK_AVAILABLE_FALSE;
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
-			&awbLockAvailable, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
+				  &awbLockAvailable, 1);
 
 	char availableControlModes = ANDROID_CONTROL_MODE_AUTO;
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_CONTROL_AVAILABLE_MODES,
-			&availableControlModes, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_CONTROL_AVAILABLE_MODES,
+				  &availableControlModes, 1);
 
 	/* JPEG static metadata. */
 	std::vector<int32_t> availableThumbnailSizes = {
 		0, 0,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
-			availableThumbnailSizes.data(),
-			availableThumbnailSizes.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
+				  availableThumbnailSizes.data(),
+				  availableThumbnailSizes.size());
 
 	/* Sensor static metadata. */
 	int32_t pixelArraySize[] = {
 		2592, 1944,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-				ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
-				&pixelArraySize, 2);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
+				  &pixelArraySize, 2);
 
 	int32_t sensorSizes[] = {
 		0, 0, 2560, 1920,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-				ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
-				&sensorSizes, 4);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
+				  &sensorSizes, 4);
 
 	int32_t sensitivityRange[] = {
 		32, 2400,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-				ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
-				&sensitivityRange, 2);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
+				  &sensitivityRange, 2);
 
 	uint16_t filterArr = ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT_GRBG;
-	ret = add_camera_metadata_entry(staticMetadata_,
-				ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
-				&filterArr, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
+				  &filterArr, 1);
 
 	int64_t exposureTimeRange[] = {
 		100000, 200000000,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-				ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
-				&exposureTimeRange, 2);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
+				  &exposureTimeRange, 2);
 
 	int32_t orientation = 0;
-	ret = add_camera_metadata_entry(staticMetadata_,
-				ANDROID_SENSOR_ORIENTATION,
-				&orientation, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_SENSOR_ORIENTATION,
+				  &orientation, 1);
 
 	std::vector<int32_t> testPatterModes = {
 		ANDROID_SENSOR_TEST_PATTERN_MODE_OFF,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-				ANDROID_SENSOR_AVAILABLE_TEST_PATTERN_MODES,
-				testPatterModes.data(), testPatterModes.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_SENSOR_AVAILABLE_TEST_PATTERN_MODES,
+				  testPatterModes.data(),
+				  testPatterModes.size());
 
 	std::vector<float> physicalSize = {
 		2592, 1944,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-				ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
-				physicalSize.data(), physicalSize.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
+				  physicalSize.data(),
+				  physicalSize.size());
 
 	uint8_t timestampSource = ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE_UNKNOWN;
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE,
-			&timestampSource, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_TIMESTAMP_SOURCE,
+				  &timestampSource, 1);
 
 	/* Statistics static metadata. */
 	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
-			&faceDetectMode, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
+				  &faceDetectMode, 1);
 
 	int32_t maxFaceCount = 0;
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
-			&maxFaceCount, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
+				  &maxFaceCount, 1);
 
 	/* Sync static metadata. */
 	int32_t maxLatency = ANDROID_SYNC_MAX_LATENCY_UNKNOWN;
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_SYNC_MAX_LATENCY, &maxLatency, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_SYNC_MAX_LATENCY, &maxLatency, 1);
 
 	/* Flash static metadata. */
 	char flashAvailable = ANDROID_FLASH_INFO_AVAILABLE_FALSE;
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_FLASH_INFO_AVAILABLE,
-			&flashAvailable, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_FLASH_INFO_AVAILABLE,
+				  &flashAvailable, 1);
 
 	/* Lens static metadata. */
 	std::vector<float> lensApertures = {
 		2.53 / 100,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-				ANDROID_LENS_INFO_AVAILABLE_APERTURES,
-				lensApertures.data(), lensApertures.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_APERTURES,
+				  lensApertures.data(),
+				  lensApertures.size());
 
 	uint8_t lensFacing = ANDROID_LENS_FACING_FRONT;
-	ret = add_camera_metadata_entry(staticMetadata_,
-				ANDROID_LENS_FACING, &lensFacing, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_LENS_FACING, &lensFacing, 1);
 
 	std::vector<float> lensFocalLenghts = {
 		1,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-				ANDROID_LENS_INFO_AVAILABLE_FOCAL_LENGTHS,
-				lensFocalLenghts.data(),
-				lensFocalLenghts.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_FOCAL_LENGTHS,
+				  lensFocalLenghts.data(),
+				  lensFocalLenghts.size());
 
 	std::vector<uint8_t> opticalStabilizations = {
 		ANDROID_LENS_OPTICAL_STABILIZATION_MODE_OFF,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-				ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
-				opticalStabilizations.data(),
-				opticalStabilizations.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
+				  opticalStabilizations.data(),
+				  opticalStabilizations.size());
 
 	float hypeFocalDistance = 0;
-	ret = add_camera_metadata_entry(staticMetadata_,
-				ANDROID_LENS_INFO_HYPERFOCAL_DISTANCE,
-				&hypeFocalDistance, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_LENS_INFO_HYPERFOCAL_DISTANCE,
+				  &hypeFocalDistance, 1);
 
 	float minFocusDistance = 0;
-	ret = add_camera_metadata_entry(staticMetadata_,
-				ANDROID_LENS_INFO_MINIMUM_FOCUS_DISTANCE,
-				&minFocusDistance, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_LENS_INFO_MINIMUM_FOCUS_DISTANCE,
+				  &minFocusDistance, 1);
 
 	/* Noise reduction modes. */
 	uint8_t noiseReductionModes = ANDROID_NOISE_REDUCTION_MODE_OFF;
-	ret = add_camera_metadata_entry(staticMetadata_,
-				ANDROID_NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES,
-				&noiseReductionModes, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES,
+				  &noiseReductionModes, 1);
 
 	/* Scaler static metadata. */
 	float maxDigitalZoom = 1;
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_SCALER_AVAILABLE_MAX_DIGITAL_ZOOM,
-			&maxDigitalZoom, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_MAX_DIGITAL_ZOOM,
+				  &maxDigitalZoom, 1);
 
 	std::vector<uint32_t> availableStreamFormats = {
 		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB,
 		ANDROID_SCALER_AVAILABLE_FORMATS_YCbCr_420_888,
 		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_SCALER_AVAILABLE_FORMATS,
-			availableStreamFormats.data(),
-			availableStreamFormats.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_FORMATS,
+				  availableStreamFormats.data(),
+				  availableStreamFormats.size());
 
 	std::vector<uint32_t> availableStreamConfigurations = {
 		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920,
@@ -447,65 +382,57 @@  camera_metadata_t *CameraDevice::getStaticMetadata()
 		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED, 2560, 1920,
 		ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS_OUTPUT,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS,
-			availableStreamConfigurations.data(),
-			availableStreamConfigurations.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS,
+				  availableStreamConfigurations.data(),
+				  availableStreamConfigurations.size());
 
 	std::vector<int64_t> availableStallDurations = {
 		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920, 33333333,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_SCALER_AVAILABLE_STALL_DURATIONS,
-			availableStallDurations.data(),
-			availableStallDurations.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_STALL_DURATIONS,
+				  availableStallDurations.data(),
+				  availableStallDurations.size());
 
 	std::vector<int64_t> minFrameDurations = {
 		ANDROID_SCALER_AVAILABLE_FORMATS_BLOB, 2560, 1920, 33333333,
 		ANDROID_SCALER_AVAILABLE_FORMATS_IMPLEMENTATION_DEFINED, 2560, 1920, 33333333,
 		ANDROID_SCALER_AVAILABLE_FORMATS_YCbCr_420_888, 2560, 1920, 33333333,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_SCALER_AVAILABLE_MIN_FRAME_DURATIONS,
-			minFrameDurations.data(), minFrameDurations.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_SCALER_AVAILABLE_MIN_FRAME_DURATIONS,
+				  minFrameDurations.data(),
+				  minFrameDurations.size());
 
 	uint8_t croppingType = ANDROID_SCALER_CROPPING_TYPE_CENTER_ONLY;
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_SCALER_CROPPING_TYPE, &croppingType, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_SCALER_CROPPING_TYPE, &croppingType, 1);
 
 	/* Info static metadata. */
 	uint8_t supportedHWLevel = ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED;
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL,
-			&supportedHWLevel, 1);
+	staticMetadata_->addEntry(ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL,
+				  &supportedHWLevel, 1);
 
 	/* Request static metadata. */
 	int32_t partialResultCount = 1;
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_REQUEST_PARTIAL_RESULT_COUNT,
-			&partialResultCount, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_REQUEST_PARTIAL_RESULT_COUNT,
+				  &partialResultCount, 1);
 
 	uint8_t maxPipelineDepth = 2;
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_REQUEST_PIPELINE_MAX_DEPTH,
-			&maxPipelineDepth, 1);
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_REQUEST_PIPELINE_MAX_DEPTH,
+				  &maxPipelineDepth, 1);
 
 	std::vector<uint8_t> availableCapabilities = {
 		ANDROID_REQUEST_AVAILABLE_CAPABILITIES_BACKWARD_COMPATIBLE,
 	};
-	ret = add_camera_metadata_entry(staticMetadata_,
-			ANDROID_REQUEST_AVAILABLE_CAPABILITIES,
-			availableCapabilities.data(),
-			availableCapabilities.size());
-	METADATA_ASSERT(ret);
+	staticMetadata_->addEntry(ANDROID_REQUEST_AVAILABLE_CAPABILITIES,
+				  availableCapabilities.data(),
+				  availableCapabilities.size());
+
+	if (!staticMetadata_->isValid()) {
+		delete staticMetadata_;
+		staticMetadata_ = nullptr;
+		return nullptr;
+	}
 
-	return staticMetadata_;
+	return staticMetadata_->get();
 }
 
 /*
@@ -513,8 +440,6 @@  camera_metadata_t *CameraDevice::getStaticMetadata()
  */
 const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
 {
-	int ret;
-
 	/*
 	 * \todo Inspect type and pick the right metadata pack.
 	 * As of now just use a single one for all templates.
@@ -545,89 +470,73 @@  const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
 	}
 
 	if (requestTemplate_)
-		return requestTemplate_;
+		return requestTemplate_->get();
 
 	/*
 	 * \todo Keep this in sync with the actual number of entries.
 	 * Currently: 12 entries, 15 bytes
 	 */
-	requestTemplate_ = allocate_camera_metadata(15, 20);
+	requestTemplate_ = new CameraMetadata(15, 20);
 	if (!requestTemplate_) {
 		LOG(HAL, Error) << "Failed to allocate template metadata";
+		delete requestTemplate_;
+		requestTemplate_ = nullptr;
 		return nullptr;
 	}
 
 	uint8_t aeMode = ANDROID_CONTROL_AE_MODE_ON;
-	ret = add_camera_metadata_entry(requestTemplate_,
-			ANDROID_CONTROL_AE_MODE,
-			&aeMode, 1);
-	METADATA_ASSERT(ret);
+	requestTemplate_->addEntry(ANDROID_CONTROL_AE_MODE,
+				   &aeMode, 1);
 
 	int32_t aeExposureCompensation = 0;
-	ret = add_camera_metadata_entry(requestTemplate_,
-			ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION,
-			&aeExposureCompensation, 1);
-	METADATA_ASSERT(ret);
+	requestTemplate_->addEntry(ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION,
+				   &aeExposureCompensation, 1);
 
 	uint8_t aePrecaptureTrigger = ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER_IDLE;
-	ret = add_camera_metadata_entry(requestTemplate_,
-			ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER,
-			&aePrecaptureTrigger, 1);
-	METADATA_ASSERT(ret);
+	requestTemplate_->addEntry(ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER,
+				   &aePrecaptureTrigger, 1);
 
 	uint8_t aeLock = ANDROID_CONTROL_AE_LOCK_OFF;
-	ret = add_camera_metadata_entry(requestTemplate_,
-			ANDROID_CONTROL_AE_LOCK,
-			&aeLock, 1);
-	METADATA_ASSERT(ret);
+	requestTemplate_->addEntry(ANDROID_CONTROL_AE_LOCK,
+				   &aeLock, 1);
 
 	uint8_t afTrigger = ANDROID_CONTROL_AF_TRIGGER_IDLE;
-	ret = add_camera_metadata_entry(requestTemplate_,
-			ANDROID_CONTROL_AF_TRIGGER,
-			&afTrigger, 1);
-	METADATA_ASSERT(ret);
+	requestTemplate_->addEntry(ANDROID_CONTROL_AF_TRIGGER,
+				   &afTrigger, 1);
 
 	uint8_t awbMode = ANDROID_CONTROL_AWB_MODE_AUTO;
-	ret = add_camera_metadata_entry(requestTemplate_,
-			ANDROID_CONTROL_AWB_MODE,
-			&awbMode, 1);
-	METADATA_ASSERT(ret);
+	requestTemplate_->addEntry(ANDROID_CONTROL_AWB_MODE,
+				   &awbMode, 1);
 
 	uint8_t awbLock = ANDROID_CONTROL_AWB_LOCK_OFF;
-	ret = add_camera_metadata_entry(requestTemplate_,
-			ANDROID_CONTROL_AWB_LOCK,
-			&awbLock, 1);
-	METADATA_ASSERT(ret);
+	requestTemplate_->addEntry(ANDROID_CONTROL_AWB_LOCK,
+				   &awbLock, 1);
 
 	uint8_t flashMode = ANDROID_FLASH_MODE_OFF;
-	ret = add_camera_metadata_entry(requestTemplate_,
-			ANDROID_FLASH_MODE,
-			&flashMode, 1);
-	METADATA_ASSERT(ret);
+	requestTemplate_->addEntry(ANDROID_FLASH_MODE,
+				   &flashMode, 1);
 
 	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
-	ret = add_camera_metadata_entry(requestTemplate_,
-			ANDROID_STATISTICS_FACE_DETECT_MODE,
-			&faceDetectMode, 1);
-	METADATA_ASSERT(ret);
+	requestTemplate_->addEntry(ANDROID_STATISTICS_FACE_DETECT_MODE,
+				   &faceDetectMode, 1);
 
 	uint8_t noiseReduction = ANDROID_NOISE_REDUCTION_MODE_OFF;
-	ret = add_camera_metadata_entry(requestTemplate_,
-			ANDROID_NOISE_REDUCTION_MODE, &noiseReduction, 1);
-	METADATA_ASSERT(ret);
+	requestTemplate_->addEntry(ANDROID_NOISE_REDUCTION_MODE,
+				   &noiseReduction, 1);
 
 	uint8_t aberrationMode = ANDROID_COLOR_CORRECTION_ABERRATION_MODE_OFF;
-	ret = add_camera_metadata_entry(requestTemplate_,
-			ANDROID_COLOR_CORRECTION_ABERRATION_MODE,
-			&aberrationMode, 1);
-	METADATA_ASSERT(ret);
+	requestTemplate_->addEntry(ANDROID_COLOR_CORRECTION_ABERRATION_MODE,
+				   &aberrationMode, 1);
+
+	requestTemplate_->addEntry(ANDROID_CONTROL_CAPTURE_INTENT,
+				   &captureIntent, 1);
 
-	ret = add_camera_metadata_entry(requestTemplate_,
-			ANDROID_CONTROL_CAPTURE_INTENT,
-			&captureIntent, 1);
-	METADATA_ASSERT(ret);
+	if (!requestTemplate_->isValid()) {
+		delete requestTemplate_;
+		requestTemplate_ = nullptr;
+	}
 
-	return requestTemplate_;
+	return requestTemplate_->get();
 }
 
 /*
@@ -799,7 +708,7 @@  void CameraDevice::requestComplete(Request *request,
 {
 	Buffer *libcameraBuffer = buffers.begin()->second;
 	camera3_buffer_status status = CAMERA3_BUFFER_STATUS_OK;
-	camera_metadata_t *resultMetadata = nullptr;
+	std::unique_ptr<CameraMetadata> resultMetadata;
 
 	if (request->status() != Request::RequestComplete) {
 		LOG(HAL, Error) << "Request not succesfully completed: "
@@ -837,16 +746,12 @@  void CameraDevice::requestComplete(Request *request,
 		captureResult.partial_result = 1;
 		resultMetadata = getResultMetadata(descriptor->frameNumber,
 						   libcameraBuffer->timestamp());
-		captureResult.result = resultMetadata;
+		captureResult.result = resultMetadata->get();
 	}
 
 	callbacks_->process_capture_result(callbacks_, &captureResult);
 
 	delete descriptor;
-	if (resultMetadata)
-		free_camera_metadata(resultMetadata);
-
-	return;
 }
 
 void CameraDevice::notifyShutter(uint32_t frameNumber, uint64_t timestamp)
@@ -875,89 +780,63 @@  void CameraDevice::notifyError(uint32_t frameNumber, camera3_stream_t *stream)
 /*
  * Produce a set of fixed result metadata.
  */
-camera_metadata_t *CameraDevice::getResultMetadata(int frame_number,
-						   int64_t timestamp)
+std::unique_ptr<CameraMetadata> CameraDevice::getResultMetadata(int frame_number,
+								int64_t timestamp)
 {
-	int ret;
-
 	/*
 	 * \todo Keep this in sync with the actual number of entries.
 	 * Currently: 13 entries, 36 bytes
 	 */
-	camera_metadata_t *resultMetadata = allocate_camera_metadata(15, 50);
+	std::unique_ptr<CameraMetadata> resultMetadata =
+		utils::make_unique<CameraMetadata>(15, 50);
+	if (!resultMetadata->isValid()) {
+		LOG(HAL, Error) << "Failed to allocate static metadata";
+		return nullptr;
+	}
 
 	const uint8_t ae_state = ANDROID_CONTROL_AE_STATE_CONVERGED;
-	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AE_STATE,
-					&ae_state, 1);
-	METADATA_ASSERT(ret);
+	resultMetadata->addEntry(ANDROID_CONTROL_AE_STATE, &ae_state, 1);
 
 	const uint8_t ae_lock = ANDROID_CONTROL_AE_LOCK_OFF;
-	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AE_LOCK,
-					&ae_lock, 1);
-	METADATA_ASSERT(ret);
+	resultMetadata->addEntry(ANDROID_CONTROL_AE_LOCK, &ae_lock, 1);
 
 	uint8_t af_state = ANDROID_CONTROL_AF_STATE_INACTIVE;
-	ret = add_camera_metadata_entry(resultMetadata, ANDROID_CONTROL_AF_STATE,
-					&af_state, 1);
-	METADATA_ASSERT(ret);
+	resultMetadata->addEntry(ANDROID_CONTROL_AF_STATE, &af_state, 1);
 
 	const uint8_t awb_state = ANDROID_CONTROL_AWB_STATE_CONVERGED;
-	ret = add_camera_metadata_entry(resultMetadata,
-					ANDROID_CONTROL_AWB_STATE,
-					&awb_state, 1);
-	METADATA_ASSERT(ret);
+	resultMetadata->addEntry(ANDROID_CONTROL_AWB_STATE, &awb_state, 1);
 
 	const uint8_t awb_lock = ANDROID_CONTROL_AWB_LOCK_OFF;
-	ret = add_camera_metadata_entry(resultMetadata,
-					ANDROID_CONTROL_AWB_LOCK,
-					&awb_lock, 1);
-	METADATA_ASSERT(ret);
+	resultMetadata->addEntry(ANDROID_CONTROL_AWB_LOCK, &awb_lock, 1);
 
 	const uint8_t lens_state = ANDROID_LENS_STATE_STATIONARY;
-	ret = add_camera_metadata_entry(resultMetadata,
-					ANDROID_LENS_STATE,
-					&lens_state, 1);
-	METADATA_ASSERT(ret);
+	resultMetadata->addEntry(ANDROID_LENS_STATE, &lens_state, 1);
 
 	int32_t sensorSizes[] = {
 		0, 0, 2560, 1920,
 	};
-	ret = add_camera_metadata_entry(resultMetadata,
-					ANDROID_SCALER_CROP_REGION,
-					sensorSizes, 4);
-	METADATA_ASSERT(ret);
+	resultMetadata->addEntry(ANDROID_SCALER_CROP_REGION, sensorSizes, 4);
 
-	ret = add_camera_metadata_entry(resultMetadata,
-					ANDROID_SENSOR_TIMESTAMP,
-					&timestamp, 1);
-	METADATA_ASSERT(ret);
+	resultMetadata->addEntry(ANDROID_SENSOR_TIMESTAMP, &timestamp, 1);
 
 	/* 33.3 msec */
 	const int64_t rolling_shutter_skew = 33300000;
-	ret = add_camera_metadata_entry(resultMetadata,
-					ANDROID_SENSOR_ROLLING_SHUTTER_SKEW,
-					&rolling_shutter_skew, 1);
-	METADATA_ASSERT(ret);
+	resultMetadata->addEntry(ANDROID_SENSOR_ROLLING_SHUTTER_SKEW,
+				 &rolling_shutter_skew, 1);
 
 	/* 16.6 msec */
 	const int64_t exposure_time = 16600000;
-	ret = add_camera_metadata_entry(resultMetadata,
-					ANDROID_SENSOR_EXPOSURE_TIME,
-					&exposure_time, 1);
-	METADATA_ASSERT(ret);
+	resultMetadata->addEntry(ANDROID_SENSOR_EXPOSURE_TIME,
+				 &exposure_time, 1);
 
 	const uint8_t lens_shading_map_mode =
 				ANDROID_STATISTICS_LENS_SHADING_MAP_MODE_OFF;
-	ret = add_camera_metadata_entry(resultMetadata,
-					ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
-					&lens_shading_map_mode, 1);
-	METADATA_ASSERT(ret);
+	resultMetadata->addEntry(ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
+				 &lens_shading_map_mode, 1);
 
 	const uint8_t scene_flicker = ANDROID_STATISTICS_SCENE_FLICKER_NONE;
-	ret = add_camera_metadata_entry(resultMetadata,
-					ANDROID_STATISTICS_SCENE_FLICKER,
-					&scene_flicker, 1);
-	METADATA_ASSERT(ret);
+	resultMetadata->addEntry(ANDROID_STATISTICS_SCENE_FLICKER,
+				 &scene_flicker, 1);
 
 	return resultMetadata;
 }
diff --git a/src/android/camera_device.h b/src/android/camera_device.h
index 7897ba9dc5c7..65ba877a02ea 100644
--- a/src/android/camera_device.h
+++ b/src/android/camera_device.h
@@ -19,13 +19,7 @@ 
 
 #include "message.h"
 
-#define METADATA_ASSERT(_r)		\
-	do {				\
-		if (!(_r)) break;	\
-		LOG(HAL, Error) << "Error: " << __func__ << ":" << __LINE__; \
-		return nullptr;		\
-	} while(0);
-
+class CameraMetadata;
 class ThreadRpc;
 
 class CameraDevice : public libcamera::Object
@@ -59,14 +53,15 @@  private:
 
 	void notifyShutter(uint32_t frameNumber, uint64_t timestamp);
 	void notifyError(uint32_t frameNumber, camera3_stream_t *stream);
-	camera_metadata_t *getResultMetadata(int frame_number, int64_t timestamp);
+	std::unique_ptr<CameraMetadata> getResultMetadata(int frame_number,
+							  int64_t timestamp);
 
 	bool running_;
 	std::shared_ptr<libcamera::Camera> camera_;
 	std::unique_ptr<libcamera::CameraConfiguration> config_;
 
-	camera_metadata_t *staticMetadata_;
-	camera_metadata_t *requestTemplate_;
+	CameraMetadata *staticMetadata_;
+	CameraMetadata *requestTemplate_;
 	const camera3_callback_ops_t *callbacks_;
 };