[libcamera-devel,v2,3/3] libcamera: pipeline: raspberrypi: Support colour spaces

13953 diff mbox series

The Raspberry Pi pipeline handler now sets colour spaces correctly.

In generateConfiguration() is sets them to reasonable default values
based on the stream role. Note how video recording streams use the
"VIDEO" YCbCr encoding, which will later be fixed up according to the
requested resolution.

validate() and configure() check the colour space is valid, and also
force all (non-raw) output streams to share the same colour space
(which is a hardware restriction). Finally, the "VIDEO" YCbCr encoding
is corrected by configure() to be one of REC601, REC709 or REC2020.

Signed-off-by: David Plowman <david.plowman@raspberrypi.com>
---
 .../pipeline/raspberrypi/raspberrypi.cpp      | 84 +++++++++++++++++++
 1 file changed, 84 insertions(+)

Hi David,

Thank you for the patch.

On Mon, Sep 27, 2021 at 01:33:27PM +0100, David Plowman wrote:
> The Raspberry Pi pipeline handler now sets colour spaces correctly.
> 
> In generateConfiguration() is sets them to reasonable default values

s/is/it/

> based on the stream role. Note how video recording streams use the
> "VIDEO" YCbCr encoding, which will later be fixed up according to the
> requested resolution.
> 
> validate() and configure() check the colour space is valid, and also
> force all (non-raw) output streams to share the same colour space
> (which is a hardware restriction). Finally, the "VIDEO" YCbCr encoding
> is corrected by configure() to be one of REC601, REC709 or REC2020.
> 
> Signed-off-by: David Plowman <david.plowman@raspberrypi.com>
> ---
>  .../pipeline/raspberrypi/raspberrypi.cpp      | 84 +++++++++++++++++++
>  1 file changed, 84 insertions(+)
> 
> diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> index 0bdfa727..33ab49d6 100644
> --- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> +++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> @@ -281,6 +281,24 @@ RPiCameraConfiguration::RPiCameraConfiguration(const RPiCameraData *data)
>  {
>  }
>  
> +static bool validateColorSpace(ColorSpace &colorSpace)
> +{
> +	const std::vector<ColorSpace> validColorSpaces = {

static ?

> +		ColorSpace::JFIF,
> +		ColorSpace::SMPTE170M,
> +		ColorSpace::REC709,
> +		ColorSpace::REC2020,
> +		ColorSpace::VIDEO,
> +	};
> +	auto it = std::find_if(validColorSpaces.begin(), validColorSpaces.end(),
> +			       [&colorSpace](const ColorSpace &item) { return colorSpace == item; });

	auto it = std::find_if(validColorSpaces.begin(), validColorSpaces.end(),
			       [&colorSpace](const ColorSpace &item) {
				       return colorSpace == item;
			       });

> +	if (it != validColorSpaces.end())
> +		return true;

You could use an std::unordered_set<ColorSpace> and just check
validColorSpaces. You'll need to define a specialization of
std::hash<ColorSpace> though.

> +
> +	colorSpace = ColorSpace::JFIF;
> +	return false;
> +}
> +
>  CameraConfiguration::Status RPiCameraConfiguration::validate()
>  {
>  	Status status = Valid;
> @@ -346,6 +364,7 @@ CameraConfiguration::Status RPiCameraConfiguration::validate()
>  	unsigned int rawCount = 0, outCount = 0, count = 0, maxIndex = 0;
>  	std::pair<int, Size> outSize[2];
>  	Size maxSize;
> +	ColorSpace colorSpace; /* colour space for all non-raw output streams */
>  	for (StreamConfiguration &cfg : config_) {
>  		if (isRaw(cfg.pixelFormat)) {
>  			/*
> @@ -354,6 +373,7 @@ CameraConfiguration::Status RPiCameraConfiguration::validate()
>  			 */
>  			V4L2VideoDevice::Formats fmts = data_->unicam_[Unicam::Image].dev()->formats();
>  			V4L2DeviceFormat sensorFormat = findBestMode(fmts, cfg.size);
> +			sensorFormat.colorSpace = ColorSpace::RAW;
>  			int ret = data_->unicam_[Unicam::Image].dev()->tryFormat(&sensorFormat);
>  			if (ret)
>  				return Invalid;

Shouldn't you set cfg.colorSpace to ColorSpace::RAW for raw stream
(possibly setting the status to Adjusted) ?

> @@ -392,6 +412,7 @@ CameraConfiguration::Status RPiCameraConfiguration::validate()
>  			if (maxSize < cfg.size) {
>  				maxSize = cfg.size;
>  				maxIndex = outCount;
> +				colorSpace = cfg.colorSpace;
>  			}
>  			outCount++;
>  		}
> @@ -405,6 +426,10 @@ CameraConfiguration::Status RPiCameraConfiguration::validate()
>  		}
>  	}
>  
> +	/* Ensure the output colour space (if present) is one we handle. */
> +	if (outCount)
> +		validateColorSpace(colorSpace);
> +
>  	/*
>  	 * Now do any fixups needed. For the two ISP outputs, one stream must be
>  	 * equal or smaller than the other in all dimensions.
> @@ -446,10 +471,26 @@ CameraConfiguration::Status RPiCameraConfiguration::validate()
>  			status = Adjusted;
>  		}
>  
> +		/* Output streams must share the same colour space. */
> +		if (cfg.colorSpace != colorSpace) {
> +			LOG(RPI, Warning) << "Output stream " << (i == maxIndex ? 0 : 1)
> +					  << " colour space changed";

Does that deserve a warning, or should it be a debug message ? Given
that there's no API to enumerate supported colour spaces (do we need one
?), applications can only try different options, so it seems to be an
expected behaviour.

> +			cfg.colorSpace = colorSpace;
> +			status = Adjusted;
> +		}
> +
>  		V4L2DeviceFormat format;
>  		format.fourcc = V4L2PixelFormat::fromPixelFormat(cfg.pixelFormat);
>  		format.size = cfg.size;
>  
> +		/*
> +		 * Request a sensible colour space. Note that "VIDEO" isn't a real
> +		 * encoding, so substitute something else sensible.
> +		 */
> +		format.colorSpace = colorSpace;
> +		if (format.colorSpace.encoding == ColorSpace::Encoding::VIDEO)
> +			format.colorSpace.encoding = ColorSpace::Encoding::REC601;

I think the substitution could be done before the loop, possibly in
validateColorSpace(). It raises the question of whether validate()
should return Adjusted or Valid in that case. This should be documented
in patch 2/3.

> +
>  		int ret = dev->tryFormat(&format);
>  		if (ret)
>  			return Invalid;
> @@ -475,6 +516,7 @@ CameraConfiguration *PipelineHandlerRPi::generateConfiguration(Camera *camera,
>  	V4L2DeviceFormat sensorFormat;
>  	unsigned int bufferCount;
>  	PixelFormat pixelFormat;
> +	ColorSpace colorSpace;
>  	V4L2VideoDevice::Formats fmts;
>  	Size size;
>  
> @@ -490,6 +532,7 @@ CameraConfiguration *PipelineHandlerRPi::generateConfiguration(Camera *camera,
>  			fmts = data->unicam_[Unicam::Image].dev()->formats();
>  			sensorFormat = findBestMode(fmts, size);
>  			pixelFormat = sensorFormat.fourcc.toPixelFormat();
> +			colorSpace = ColorSpace::RAW;
>  			ASSERT(pixelFormat.isValid());
>  			bufferCount = 2;
>  			rawCount++;
> @@ -501,6 +544,7 @@ CameraConfiguration *PipelineHandlerRPi::generateConfiguration(Camera *camera,
>  			/* Return the largest sensor resolution. */
>  			size = data->sensor_->resolution();
>  			bufferCount = 1;
> +			colorSpace = ColorSpace::JFIF;
>  			outCount++;
>  			break;
>  
> @@ -517,6 +561,7 @@ CameraConfiguration *PipelineHandlerRPi::generateConfiguration(Camera *camera,
>  			pixelFormat = formats::YUV420;
>  			size = { 1920, 1080 };
>  			bufferCount = 4;
> +			colorSpace = ColorSpace::VIDEO;
>  			outCount++;
>  			break;
>  
> @@ -525,6 +570,7 @@ CameraConfiguration *PipelineHandlerRPi::generateConfiguration(Camera *camera,
>  			pixelFormat = formats::ARGB8888;
>  			size = { 800, 600 };
>  			bufferCount = 4;
> +			colorSpace = ColorSpace::JFIF;
>  			outCount++;
>  			break;
>  
> @@ -554,6 +600,7 @@ CameraConfiguration *PipelineHandlerRPi::generateConfiguration(Camera *camera,
>  		StreamConfiguration cfg(formats);
>  		cfg.size = size;
>  		cfg.pixelFormat = pixelFormat;
> +		cfg.colorSpace = colorSpace;
>  		cfg.bufferCount = bufferCount;
>  		config->addConfiguration(cfg);
>  	}
> @@ -575,6 +622,7 @@ int PipelineHandlerRPi::configure(Camera *camera, CameraConfiguration *config)
>  	Size maxSize, sensorSize;
>  	unsigned int maxIndex = 0;
>  	bool rawStream = false;
> +	ColorSpace colorSpace; /* colour space for all non-raw output streams */
>  
>  	/*
>  	 * Look for the RAW stream (if given) size as well as the largest
> @@ -593,14 +641,40 @@ int PipelineHandlerRPi::configure(Camera *camera, CameraConfiguration *config)
>  		} else {
>  			if (cfg.size > maxSize) {
>  				maxSize = config->at(i).size;
> +				colorSpace = config->at(i).colorSpace;
>  				maxIndex = i;
>  			}
>  		}
>  	}
>  
> +	if (maxSize.isNull()) {
> +		/*
> +		 * No non-raw streams, so some will get made below. Doesn't matter
> +		 * what colour space we assign to them.
> +		 */
> +		colorSpace = ColorSpace::JFIF;
> +	} else {
> +		/* Make sure we can handle this colour space. */
> +		validateColorSpace(colorSpace);

configure() is guaranteed to be called with a valid configuration, so I
think you can skip this.

> +
> +		/*
> +		 * The "VIDEO" colour encoding means that we choose one of REC601,
> +		 * REC709 or REC2020 automatically according to the resolution.
> +		 */
> +		if (colorSpace.encoding == ColorSpace::Encoding::VIDEO) {

Same here, this should have been adjusted in validate().

> +			if (maxSize.width >= 3840)
> +				colorSpace.encoding = ColorSpace::Encoding::REC2020;
> +			else if (maxSize.width >= 1280)
> +				colorSpace.encoding = ColorSpace::Encoding::REC709;
> +			else
> +				colorSpace.encoding = ColorSpace::Encoding::REC601;
> +		}
> +	}
> +
>  	/* First calculate the best sensor mode we can use based on the user request. */
>  	V4L2VideoDevice::Formats fmts = data->unicam_[Unicam::Image].dev()->formats();
>  	V4L2DeviceFormat sensorFormat = findBestMode(fmts, rawStream ? sensorSize : maxSize);
> +	sensorFormat.colorSpace = ColorSpace::RAW;
>  
>  	/*
>  	 * Unicam image output format. The ISP input format gets set at start,
> @@ -638,11 +712,18 @@ int PipelineHandlerRPi::configure(Camera *camera, CameraConfiguration *config)
>  		StreamConfiguration &cfg = config->at(i);
>  
>  		if (isRaw(cfg.pixelFormat)) {
> +			cfg.colorSpace = ColorSpace::RAW;

Ditto, and for the next change too.

>  			cfg.setStream(&data->unicam_[Unicam::Image]);
>  			data->unicam_[Unicam::Image].setExternal(true);
>  			continue;
>  		}
>  
> +		/* All other streams share the same colour space. */
> +		if (cfg.colorSpace != colorSpace) {
> +			LOG(RPI, Warning) << "Stream " << i << " colour space changed";
> +			cfg.colorSpace = colorSpace;
> +		}
> +
>  		/* The largest resolution gets routed to the ISP Output 0 node. */
>  		RPi::Stream *stream = i == maxIndex ? &data->isp_[Isp::Output0]
>  						    : &data->isp_[Isp::Output1];
> @@ -650,6 +731,7 @@ int PipelineHandlerRPi::configure(Camera *camera, CameraConfiguration *config)
>  		V4L2PixelFormat fourcc = V4L2PixelFormat::fromPixelFormat(cfg.pixelFormat);
>  		format.size = cfg.size;
>  		format.fourcc = fourcc;
> +		format.colorSpace = cfg.colorSpace;
>  
>  		LOG(RPI, Debug) << "Setting " << stream->name() << " to "
>  				<< format.toString();
> @@ -689,6 +771,7 @@ int PipelineHandlerRPi::configure(Camera *camera, CameraConfiguration *config)
>  		format = {};
>  		format.size = maxSize;
>  		format.fourcc = V4L2PixelFormat::fromPixelFormat(formats::YUV420);
> +		format.colorSpace = colorSpace;
>  		ret = data->isp_[Isp::Output0].dev()->setFormat(&format);
>  		if (ret) {
>  			LOG(RPI, Error)
> @@ -718,6 +801,7 @@ int PipelineHandlerRPi::configure(Camera *camera, CameraConfiguration *config)
>  		const Size limit = maxDimensions.boundedToAspectRatio(format.size);
>  
>  		output1Format.size = (format.size / 2).boundedTo(limit).alignedDownTo(2, 2);
> +		output1Format.colorSpace = colorSpace;
>  
>  		LOG(RPI, Debug) << "Setting ISP Output1 (internal) to "
>  				<< output1Format.toString();