[libcamera-devel] [PATCH v2 16/16] libcamera: pipeline: uvcvideo: Add format information and validation

[Jacopo Mondi]

Hi Niklas,

On Wed, Jun 12, 2019 at 02:43:59AM +0200, Niklas Söderlund wrote:
> Extend the uvcvideo pipeline with format information and validation. The
> format information is gathered by enumerating the v4l2 device. This
> enumeration approach is valid for UVC as it has a static and simple
> media graph.
>
> Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> ---
>  src/libcamera/pipeline/uvcvideo.cpp | 41 ++++++++++++++++++++++-------
>  1 file changed, 31 insertions(+), 10 deletions(-)
>
> diff --git a/src/libcamera/pipeline/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo.cpp
> index 45260f34c8f5daba..7ca9d0eefe8223e8 100644
> --- a/src/libcamera/pipeline/uvcvideo.cpp
> +++ b/src/libcamera/pipeline/uvcvideo.cpp
> @@ -5,6 +5,8 @@
>   * uvcvideo.cpp - Pipeline handler for uvcvideo devices
>   */
>
> +#include <algorithm>
> +
>  #include <libcamera/camera.h>
>  #include <libcamera/request.h>
>  #include <libcamera/stream.h>
> @@ -95,18 +97,33 @@ CameraConfiguration::Status UVCCameraConfiguration::validate()
>  	}
>
>  	StreamConfiguration &cfg = config_[0];
> -
> -	/* \todo: Validate the configuration against the device capabilities. */
> +	const StreamFormats &formats = cfg.formats();
>  	const unsigned int pixelFormat = cfg.pixelFormat;
>  	const Size size = cfg.size;
>
> -	cfg.pixelFormat = V4L2_PIX_FMT_YUYV;
> -	cfg.size = { 640, 480 };
> +	const std::vector<unsigned int> pixelFormats = formats.pixelformats();
> +	auto iter = std::find(pixelFormats.begin(), pixelFormats.end(), pixelFormat);
> +	if (iter == pixelFormats.end()) {
> +		cfg.pixelFormat = pixelFormats.front();
> +		LOG(UVC, Debug)
> +			<< "Adjusting pixel format from " << pixelFormat
> +			<< " to " << cfg.pixelFormat;
> +		status = Adjusted;
> +	}
> +
> +	const std::vector<Size> &formatSizes = formats.sizes(cfg.pixelFormat);
> +	cfg.size = formatSizes.front();
> +	for (const Size &formatsSize : formatSizes) {
> +		if (formatsSize > size)
> +			break;
> +
> +		cfg.size = formatsSize;
> +	}

Even this selects not the closest size, but the smallest closest one, I
think it's fine for now.
>
> -	if (cfg.pixelFormat != pixelFormat || cfg.size != size) {
> +	if (cfg.size != size) {
>  		LOG(UVC, Debug)
> -			<< "Adjusting configuration from " << cfg.toString()
> -			<< " to " << cfg.size.toString() << "-YUYV";
> +			<< "Adjusting size from " << size.toString()
> +			<< " to " << cfg.size.toString();
>  		status = Adjusted;
>  	}
>
> @@ -123,14 +140,18 @@ PipelineHandlerUVC::PipelineHandlerUVC(CameraManager *manager)
>  CameraConfiguration *PipelineHandlerUVC::generateConfiguration(Camera *camera,
>  	const StreamRoles &roles)
>  {
> +	UVCCameraData *data = cameraData(camera);
>  	CameraConfiguration *config = new UVCCameraConfiguration();
>
>  	if (roles.empty())
>  		return config;
>
> -	StreamConfiguration cfg{};
> -	cfg.pixelFormat = V4L2_PIX_FMT_YUYV;
> -	cfg.size = { 640, 480 };
> +	ImageFormats v4l2formats = data->video_->formats();
> +	StreamFormats formats(v4l2formats.data());

Do we want to be able to construct a StreamFormat from an ImageFormat?


Minors apart
Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>

Thanks
  j

> +	StreamConfiguration cfg(formats);
> +
> +	cfg.pixelFormat = formats.pixelformats().front();
> +	cfg.size = formats.sizes(cfg.pixelFormat).back();
>  	cfg.bufferCount = 4;
>
>  	config->addConfiguration(cfg);
> --
> 2.21.0
>
> _______________________________________________
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> libcamera-devel at lists.libcamera.org
> https://lists.libcamera.org/listinfo/libcamera-devel
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