[libcamera-devel] [PATCH v2 14/27] gst: utils: Add StreamConfiguration helpers

[Laurent Pinchart]

Hi Nicolas,

Thank you for the patch.

On Thu, Feb 27, 2020 at 03:03:54PM -0500, Nicolas Dufresne wrote:
> This add helpers to deal with the conversion from StreamConfiguration

s/add/adds/

> to caps and vis-versa. This is needed to implement caps negotiation.

s/vis/vice/

> 
> Signed-off-by: Nicolas Dufresne <nicolas.dufresne at collabora.com>
> ---
>  src/gstreamer/gstlibcamera-utils.cpp | 64 ++++++++++++++++++++++++++++
>  src/gstreamer/gstlibcamera-utils.h   |  3 ++
>  2 files changed, 67 insertions(+)
> 
> diff --git a/src/gstreamer/gstlibcamera-utils.cpp b/src/gstreamer/gstlibcamera-utils.cpp
> index dc129c3..231f3c5 100644
> --- a/src/gstreamer/gstlibcamera-utils.cpp
> +++ b/src/gstreamer/gstlibcamera-utils.cpp
> @@ -40,6 +40,18 @@ drm_to_gst_format(guint drm_fourcc)
>  	return GST_VIDEO_FORMAT_UNKNOWN;
>  }
>  
> +static inline guint

Shouldn't we let the compiler decide whether to inline the function ?

> +gst_format_to_drm(GstVideoFormat gst_format)
> +{
> +	if (gst_format == GST_VIDEO_FORMAT_ENCODED)
> +		return DRM_FORMAT_INVALID;
> +
> +	for (const auto &item : format_map)
	for (const auto &item : format_map) {
> +		if (item.gst_format == gst_format)
> +			return item.drm_fourcc;
	}

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

> +	return DRM_FORMAT_INVALID;
> +}
> +
>  static GstStructure *
>  bare_structure_from_fourcc(guint fourcc)
>  {
> @@ -96,3 +108,55 @@ gst_libcamera_stream_formats_to_caps(const StreamFormats &formats)
>  
>  	return caps;
>  }
> +
> +GstCaps *
> +gst_libcamera_stream_configuration_to_caps(const StreamConfiguration &stream_cfg)
> +{
> +	GstCaps *caps = gst_caps_new_empty();
> +	GstStructure *s = bare_structure_from_fourcc(stream_cfg.pixelFormat);
> +
> +	gst_structure_set(s,
> +			  "width", G_TYPE_INT, stream_cfg.size.width,
> +			  "height", G_TYPE_INT, stream_cfg.size.height,
> +			  nullptr);
> +	gst_caps_append_structure(caps, s);
> +
> +	return caps;
> +}
> +
> +void
> +gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg,
> +					 GstCaps *caps)
> +{
> +	GstVideoFormat gst_format = drm_to_gst_format(stream_cfg.pixelFormat);
> +
> +	/* First fixate the caps using default configuration value */
> +	g_assert(gst_caps_is_writable(caps));
> +	caps = gst_caps_truncate(caps);
> +	GstStructure *s = gst_caps_get_structure(caps, 0);
> +
> +	gst_structure_fixate_field_nearest_int(s, "width", stream_cfg.size.width);
> +	gst_structure_fixate_field_nearest_int(s, "height", stream_cfg.size.height);
> +
> +	if (gst_structure_has_name(s, "video/x-raw")) {
> +		const gchar *format = gst_video_format_to_string(gst_format);
> +		gst_structure_fixate_field_string(s, "format", format);
> +	}
> +
> +	/* Then configure the stream with the result. */
> +	if (gst_structure_has_name(s, "video/x-raw")) {
> +		const gchar *format = gst_structure_get_string(s, "format");
> +		gst_format = gst_video_format_from_string(format);
> +		stream_cfg.pixelFormat = gst_format_to_drm(gst_format);
> +	} else if (gst_structure_has_name(s, "image/jpeg")) {
> +		stream_cfg.pixelFormat = DRM_FORMAT_MJPEG;
> +	} else {
> +		g_critical("Unsupported media type: %s", gst_structure_get_name(s));
> +	}
> +
> +	gint width, height;
> +	gst_structure_get_int(s, "width", &width);
> +	gst_structure_get_int(s, "height", &height);
> +	stream_cfg.size.width = width;
> +	stream_cfg.size.height = height;
> +}
> diff --git a/src/gstreamer/gstlibcamera-utils.h b/src/gstreamer/gstlibcamera-utils.h
> index 737ca63..51898a0 100644
> --- a/src/gstreamer/gstlibcamera-utils.h
> +++ b/src/gstreamer/gstlibcamera-utils.h
> @@ -14,6 +14,9 @@
>  #include <libcamera/stream.h>
>  
>  GstCaps *gst_libcamera_stream_formats_to_caps(const libcamera::StreamFormats &formats);
> +GstCaps *gst_libcamera_stream_configuration_to_caps(const libcamera::StreamConfiguration &stream_cfg);
> +void gst_libcamera_configure_stream_from_caps(libcamera::StreamConfiguration &stream_cfg,
> +					      GstCaps *caps);
>  
>  /**
>   * \class GLibLocker

-- 
Regards,

Laurent Pinchart