[PATCH v3] gstreamer: Implement caps negotiation for video/x-bayer

[Nicolas Dufresne]

Thanks.

Le lundi 04 novembre 2024 à 12:36 +0100, mailinglist1 at johanneskirchmair.de a
écrit :
> From: Johannes Kirchmair <johannes.kirchmair at skidata.com>
> 
> The parsing of video/x-bayer sources from string makes it possible to
> use cameras providing e.g SGRBG8 streams via gst-launch.
> 
> Like:
> gst-launch-1.0 libcamerasrc camera-name=<cam> ! video/x-bayer,format=grbg
> 
> Without this change the gstreamer plugin complains about "Unsupported
> media type: video/x-bayer".
> 
> Signed-off-by: Johannes Kirchmair <johannes.kirchmair at skidata.com>

Reviewed-by: Nicolas Dufresne <nicolas.dufresne at collabora.com>

> 
> Changes in v3:
> - commit msg "parsing" -> "negotiations" and "is"->"it"
> - change format argument of bayer_format_to_string to PixelFormat
> - make bayer_format_to_string return nullptr if no entry found
> - make bayer_formats const
> - use range-based for loops
> 
> Changes in v2:
> - Coding style changes
> - Removed printf that slipped in
> ---
>  src/gstreamer/gstlibcamera-utils.cpp | 87 ++++++++++++++--------------
>  1 file changed, 44 insertions(+), 43 deletions(-)
> 
> diff --git a/src/gstreamer/gstlibcamera-utils.cpp b/src/gstreamer/gstlibcamera-utils.cpp
> index 79f71246..0820c4b8 100644
> --- a/src/gstreamer/gstlibcamera-utils.cpp
> +++ b/src/gstreamer/gstlibcamera-utils.cpp
> @@ -254,52 +254,50 @@ gst_format_to_pixel_format(GstVideoFormat gst_format)
>  	return PixelFormat{};
>  }
>  
> +static const struct {
> +	PixelFormat format;
> +	const gchar *name;
> +} bayer_map[]{
> +	{ formats::SBGGR8, "bggr" },
> +	{ formats::SGBRG8, "gbrg" },
> +	{ formats::SGRBG8, "grbg" },
> +	{ formats::SRGGB8, "rggb" },
> +	{ formats::SBGGR10, "bggr10le" },
> +	{ formats::SGBRG10, "gbrg10le" },
> +	{ formats::SGRBG10, "grbg10le" },
> +	{ formats::SRGGB10, "rggb10le" },
> +	{ formats::SBGGR12, "bggr12le" },
> +	{ formats::SGBRG12, "gbrg12le" },
> +	{ formats::SGRBG12, "grbg12le" },
> +	{ formats::SRGGB12, "rggb12le" },
> +	{ formats::SBGGR14, "bggr14le" },
> +	{ formats::SGBRG14, "gbrg14le" },
> +	{ formats::SGRBG14, "grbg14le" },
> +	{ formats::SRGGB14, "rggb14le" },
> +	{ formats::SBGGR16, "bggr16le" },
> +	{ formats::SGBRG16, "gbrg16le" },
> +	{ formats::SGRBG16, "grbg16le" },
> +	{ formats::SRGGB16, "rggb16le" },
> +};
> +
>  static const gchar *
> -bayer_format_to_string(int format)
> +bayer_format_to_string(PixelFormat format)
>  {
> -	switch (format) {
> -	case formats::SBGGR8:
> -		return "bggr";
> -	case formats::SGBRG8:
> -		return "gbrg";
> -	case formats::SGRBG8:
> -		return "grbg";
> -	case formats::SRGGB8:
> -		return "rggb";
> -	case formats::SBGGR10:
> -		return "bggr10le";
> -	case formats::SGBRG10:
> -		return "gbrg10le";
> -	case formats::SGRBG10:
> -		return "grbg10le";
> -	case formats::SRGGB10:
> -		return "rggb10le";
> -	case formats::SBGGR12:
> -		return "bggr12le";
> -	case formats::SGBRG12:
> -		return "gbrg12le";
> -	case formats::SGRBG12:
> -		return "grbg12le";
> -	case formats::SRGGB12:
> -		return "rggb12le";
> -	case formats::SBGGR14:
> -		return "bggr14le";
> -	case formats::SGBRG14:
> -		return "gbrg14le";
> -	case formats::SGRBG14:
> -		return "grbg14le";
> -	case formats::SRGGB14:
> -		return "rggb14le";
> -	case formats::SBGGR16:
> -		return "bggr16le";
> -	case formats::SGBRG16:
> -		return "gbrg16le";
> -	case formats::SGRBG16:
> -		return "grbg16le";
> -	case formats::SRGGB16:
> -		return "rggb16le";
> +	for (auto &b: bayer_map) {
> +		if (b.format == format)
> +			return b.name;
>  	}
> -	return NULL;
> +	return nullptr;
> +}
> +
> +static PixelFormat
> +bayer_format_from_string(const gchar *name)
> +{
> +	for (auto &b: bayer_map) {
> +		if (strcmp(b.name, name) == 0)
> +			return b.format;
> +	}
> +	return PixelFormat{};
>  }
>  
>  static GstStructure *
> @@ -474,6 +472,9 @@ gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg,
>  		const gchar *format = gst_structure_get_string(s, "format");
>  		gst_format = gst_video_format_from_string(format);
>  		stream_cfg.pixelFormat = gst_format_to_pixel_format(gst_format);
> +	} else if (gst_structure_has_name(s, "video/x-bayer")) {
> +		const gchar *format = gst_structure_get_string(s, "format");
> +		stream_cfg.pixelFormat = bayer_format_from_string(format);
>  	} else if (gst_structure_has_name(s, "image/jpeg")) {
>  		stream_cfg.pixelFormat = formats::MJPEG;
>  	} else {