[libcamera-devel,v6,6/9] android: Add helpers for setting android metadata from libcamera controls

13164 diff mbox series

Add helpers for setting android metadata from libcamera controls.

There are two versions, for scalars and collections, both of which take
a default value to fill in the android control if the libcamera control
is not found. They both return the value that was set.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>

---
Changes in v6:
- remove unused scalar-no-default version
- remove explicit template parameters
  - infer the template parameters from the Control type

Changes in v4:
- remove vector copy from the vector setter

Changes in v3:
- setMetadata for collection only works with vectors
- change enum to enum class
- add two template parameters for android type and libcamera type
- add docs

New in v2

TODO: make ControlList versions so that we can use them in result
metadata
---
 src/android/camera_capabilities.cpp | 88 +++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)

Hi Paul,

Thank you for the patch.

On Fri, Jul 30, 2021 at 07:35:33PM +0900, Paul Elder wrote:
> Add helpers for setting android metadata from libcamera controls.
> 
> There are two versions, for scalars and collections, both of which take
> a default value to fill in the android control if the libcamera control
> is not found. They both return the value that was set.
> 
> Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
> 
> ---
> Changes in v6:
> - remove unused scalar-no-default version
> - remove explicit template parameters
>   - infer the template parameters from the Control type
> 
> Changes in v4:
> - remove vector copy from the vector setter
> 
> Changes in v3:
> - setMetadata for collection only works with vectors
> - change enum to enum class
> - add two template parameters for android type and libcamera type
> - add docs
> 
> New in v2
> 
> TODO: make ControlList versions so that we can use them in result
> metadata
> ---
>  src/android/camera_capabilities.cpp | 88 +++++++++++++++++++++++++++++
>  1 file changed, 88 insertions(+)
> 
> diff --git a/src/android/camera_capabilities.cpp b/src/android/camera_capabilities.cpp
> index b59a854f..fa701843 100644
> --- a/src/android/camera_capabilities.cpp
> +++ b/src/android/camera_capabilities.cpp
> @@ -11,6 +11,7 @@
>  #include <array>
>  #include <cmath>
>  #include <map>
> +#include <type_traits>
>  
>  #include <hardware/camera3.h>
>  
> @@ -125,6 +126,93 @@ hwLevelStrings = {
>  	{ ANDROID_INFO_SUPPORTED_HARDWARE_LEVEL_EXTERNAL, "EXTERNAL" },
>  };
>  
> +enum class ControlRange {
> +	Min,
> +	Def,
> +	Max,
> +};
> +
> +/**
> + * \brief Set android metadata from libcamera ControlInfo or a default value
> + * \tparam T Type of the control in libcamera
> + * \tparam U Type of the control in android

s/control/metadata/
s/android/Android/

> + * \param[in] metadata Android metadata pack to add the control value to
> + * \param[in] tag Android metadata tag
> + * \param[in] controlsInfo libcamera ControlInfoMap from which to find the control info
> + * \param[in] control libcamera ControlId to find from \a controlsInfo
> + * \param[in] controlRange Whether to use the min, def, or max value from the control info
> + * \param[in] defaultValue The value to set in \a metadata if \a control is not found
> + *
> + * Set the android metadata entry in \a metadata with tag \a tag based on the

s/android/Android/

> + * control info found for the libcamera control \a control in the libcamera
> + * ControlInfoMap \a controlsInfo. If no libcamera ControlInfo is found, then
> + * the android metadata entry is set to \a defaultValue.

Here too.

> + *
> + * This function is for scalar values.
> + */
> +template<typename T, typename U>
> +U setMetadata(CameraMetadata *metadata, uint32_t tag,
> +	      const ControlInfoMap &controlsInfo, const Control<T> *control,

As control can't be null, I'd pass it by reference.

> +	      enum ControlRange controlRange, const U defaultValue)
> +{
> +	U ret = defaultValue;

I'd name the variable value instead of ret.

> +
> +	const auto &info = controlsInfo.find(reinterpret_cast<const ControlId *>(control));

You don't need the cast here, Control<T> inherits from ControlId.

> +	if (info != controlsInfo.end()) {
> +		switch (controlRange) {
> +		case ControlRange::Min:
> +			ret = static_cast<U>(info->second.min().get<T>());

As a side effect, however, dropping the cast requires writing this as

			ret = static_cast<U>(info->second.min().template get<T>());

I have no idea why the cast makes a difference. Same below.

All these comments apply to the next function as well.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> +			break;
> +		case ControlRange::Def:
> +			ret = static_cast<U>(info->second.def().get<T>());
> +			break;
> +		case ControlRange::Max:
> +			ret = static_cast<U>(info->second.max().get<T>());
> +			break;
> +		}
> +	}
> +
> +	metadata->addEntry(tag, ret);
> +	return ret;
> +}
> +
> +/**
> + * \brief Set android metadata from libcamera ControlInfo or a default value
> + * \tparam T Type of the control in libcamera
> + * \tparam U Type of the control in android
> + * \param[in] metadata Android metadata pack to add the control value to
> + * \param[in] tag Android metadata tag
> + * \param[in] controlsInfo libcamera ControlInfoMap from which to find the control info
> + * \param[in] control libcamera ControlId to find from \a controlsInfo
> + * \param[in] defaultVector The value to set in \a metadata if \a control is not found
> + *
> + * Set the android metadata entry in \a metadata with tag \a tag based on the
> + * control info found for the libcamera control \a control in the libcamera
> + * ControlInfoMap \a controlsInfo. If no libcamera ControlInfo is found, then
> + * the android metadata entry is set to \a defaultVector.
> + *
> + * This function is for vector values.
> + */
> +template<typename T, typename U>
> +std::vector<U> setMetadata(CameraMetadata *metadata, uint32_t tag,
> +			   const ControlInfoMap &controlsInfo,
> +			   const Control<T> *control,
> +			   const std::vector<U> &defaultVector)
> +{
> +	const auto &info = controlsInfo.find(reinterpret_cast<const ControlId *>(control));
> +	if (info == controlsInfo.end()) {
> +		metadata->addEntry(tag, defaultVector);
> +		return defaultVector;
> +	}
> +
> +	std::vector<U> ret(info->second.values().size());
> +	for (const auto &value : info->second.values())
> +		ret.push_back(static_cast<U>(value.get<T>()));
> +	metadata->addEntry(tag, ret);
> +
> +	return ret;
> +}
> +
>  } /* namespace */
>  
>  bool CameraCapabilities::validateManualSensorCapability()