[libcamera-devel] [PATCH v2] gstreamer: Provide colorimetry <> ColorSpace mappings
Umang Jain
umang.jain at ideasonboard.com
Fri Jul 29 12:38:46 CEST 2022
From: Rishikesh Donadkar <rishikeshdonadkar at gmail.com>
Provide colorimetry <=> libcamera::ColorSpace mappings via:
- GstVideoColorimetry colorimetry_from_colorspace(colorspace);
- ColorSpace colorspace_from_colorimetry(colorimetry);
Read the colorimetry field from caps into the stream configuration.
After stream validation, the sensor supported colorimetry will
be retrieved and the caps will be updated accordingly.
Colorimetry support for gstlibcamerasrc currently undertakes only one
argument. Multiple colorimetry support shall be introduced in
subsequent commits.
Signed-off-by: Rishikesh Donadkar <rishikeshdonadkar at gmail.com>
Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
---
Changes in v2:
- Drop "Default" Colorspace
- Improve function signature of colorimetry_from_colorspace() and
colorspace_from_colorimetry()
- Map GST_VIDEO_COLOR_MATRIX_RGB to Colorspace::YcbcrEncoding::Rec601
(comes from the kernel)
- Map GST_VIDEO_COLOR_PRIMARIES_UNKNOWN to Raw colorspace
- Map ColorSpace::YcbcrEncoding::Rec601 to GST_VIDEO_COLOR_MATRIX_RGB
if colorspace is "sRGB". GST_VIDEO_COLOR_MATRIX_BT601 for all other
cases
- Minor nits regarding error reporting strings.
---
src/gstreamer/gstlibcamera-utils.cpp | 164 +++++++++++++++++++++++++++
1 file changed, 164 insertions(+)
diff --git a/src/gstreamer/gstlibcamera-utils.cpp b/src/gstreamer/gstlibcamera-utils.cpp
index c97c0d43..e4ff1269 100644
--- a/src/gstreamer/gstlibcamera-utils.cpp
+++ b/src/gstreamer/gstlibcamera-utils.cpp
@@ -45,6 +45,146 @@ static struct {
/* \todo NV42 is used in libcamera but is not mapped in GStreamer yet. */
};
+static GstVideoColorimetry
+colorimetry_from_colorspace(const ColorSpace &colorSpace)
+{
+ GstVideoColorimetry colorimetry;
+
+ switch (colorSpace.primaries) {
+ case ColorSpace::Primaries::Rec709:
+ colorimetry.primaries = GST_VIDEO_COLOR_PRIMARIES_BT709;
+ break;
+ case ColorSpace::Primaries::Rec2020:
+ colorimetry.primaries = GST_VIDEO_COLOR_PRIMARIES_BT2020;
+ break;
+ case ColorSpace::Primaries::Smpte170m:
+ colorimetry.primaries = GST_VIDEO_COLOR_PRIMARIES_SMPTE170M;
+ break;
+ case ColorSpace::Primaries::Raw:
+ colorimetry.primaries = GST_VIDEO_COLOR_PRIMARIES_UNKNOWN;
+ break;
+ }
+
+ switch (colorSpace.transferFunction) {
+ case ColorSpace::TransferFunction::Rec709:
+ colorimetry.transfer = GST_VIDEO_TRANSFER_BT709;
+ break;
+ case ColorSpace::TransferFunction::Srgb:
+ colorimetry.transfer = GST_VIDEO_TRANSFER_SRGB;
+ break;
+ case ColorSpace::TransferFunction::Linear:
+ colorimetry.transfer = GST_VIDEO_TRANSFER_GAMMA10;
+ break;
+ }
+
+ switch (colorSpace.ycbcrEncoding) {
+ case ColorSpace::YcbcrEncoding::None:
+ colorimetry.matrix = GST_VIDEO_COLOR_MATRIX_RGB;
+ break;
+ case ColorSpace::YcbcrEncoding::Rec709:
+ colorimetry.matrix = GST_VIDEO_COLOR_MATRIX_BT709;
+ break;
+ case ColorSpace::YcbcrEncoding::Rec2020:
+ colorimetry.matrix = GST_VIDEO_COLOR_MATRIX_BT2020;
+ break;
+ case ColorSpace::YcbcrEncoding::Rec601:
+ if (colorSpace == ColorSpace::Srgb)
+ colorimetry.matrix = GST_VIDEO_COLOR_MATRIX_RGB;
+ else
+ colorimetry.matrix = GST_VIDEO_COLOR_MATRIX_BT601;
+ break;
+ }
+
+ switch (colorSpace.range) {
+ case ColorSpace::Range::Full:
+ colorimetry.range = GST_VIDEO_COLOR_RANGE_0_255;
+ break;
+ case ColorSpace::Range::Limited:
+ colorimetry.range = GST_VIDEO_COLOR_RANGE_16_235;
+ break;
+ }
+
+ return colorimetry;
+}
+
+static ColorSpace
+colorspace_from_colorimetry(const GstVideoColorimetry &colorimetry)
+{
+ ColorSpace colorspace = ColorSpace::Raw;
+
+ switch (colorimetry.primaries) {
+ case GST_VIDEO_COLOR_PRIMARIES_BT709:
+ colorspace.primaries = ColorSpace::Primaries::Rec709;
+ break;
+ case GST_VIDEO_COLOR_PRIMARIES_BT2020:
+ colorspace.primaries = ColorSpace::Primaries::Rec2020;
+ break;
+ case GST_VIDEO_COLOR_PRIMARIES_SMPTE170M:
+ colorspace.primaries = ColorSpace::Primaries::Smpte170m;
+ break;
+ case GST_VIDEO_COLOR_PRIMARIES_UNKNOWN:
+ /* Unknown primaries map to raw colorspace in gstreamer */
+ return colorspace;
+ default:
+ g_error("Unsupported colorimetry primaries: %d", colorimetry.primaries);
+ }
+
+ switch (colorimetry.transfer) {
+ /* Transfer function mappings inspired from v4l2src plugin */
+ case GST_VIDEO_TRANSFER_GAMMA18:
+ case GST_VIDEO_TRANSFER_GAMMA20:
+ case GST_VIDEO_TRANSFER_GAMMA22:
+ case GST_VIDEO_TRANSFER_GAMMA28:
+ GST_WARNING("GAMMA 18, 20, 22, 28 transfer functions not supported");
+ /* fallthrough */
+ case GST_VIDEO_TRANSFER_GAMMA10:
+ colorspace.transferFunction = ColorSpace::TransferFunction::Linear;
+ break;
+ case GST_VIDEO_TRANSFER_BT601:
+ case GST_VIDEO_TRANSFER_BT2020_12:
+ case GST_VIDEO_TRANSFER_BT2020_10:
+ case GST_VIDEO_TRANSFER_BT709:
+ colorspace.transferFunction = ColorSpace::TransferFunction::Rec709;
+ break;
+ case GST_VIDEO_TRANSFER_SRGB:
+ colorspace.transferFunction = ColorSpace::TransferFunction::Srgb;
+ break;
+ default:
+ g_error("Unsupported colorimetry transfer function: %d", colorimetry.transfer);
+ }
+
+ switch (colorimetry.matrix) {
+ /* FCC is about the same as BT601 with less digit */
+ case GST_VIDEO_COLOR_MATRIX_FCC:
+ case GST_VIDEO_COLOR_MATRIX_BT601:
+ /* v4l2_ycbcr_encoding of sRGB is ENC_601 in the kernel */
+ case GST_VIDEO_COLOR_MATRIX_RGB:
+ colorspace.ycbcrEncoding = ColorSpace::YcbcrEncoding::Rec601;
+ break;
+ case GST_VIDEO_COLOR_MATRIX_BT709:
+ colorspace.ycbcrEncoding = ColorSpace::YcbcrEncoding::Rec709;
+ break;
+ case GST_VIDEO_COLOR_MATRIX_BT2020:
+ colorspace.ycbcrEncoding = ColorSpace::YcbcrEncoding::Rec2020;
+ break;
+ default:
+ g_error("Unsupported colorimetry matrix: %d", colorimetry.matrix);
+ }
+
+ switch (colorimetry.range) {
+ case GST_VIDEO_COLOR_RANGE_0_255:
+ colorspace.range = ColorSpace::Range::Full;
+ break;
+ case GST_VIDEO_COLOR_RANGE_16_235:
+ colorspace.range = ColorSpace::Range::Limited;
+ break;
+ default:
+ g_error("Unsupported colorimetry range %d", colorimetry.range);
+ }
+
+ return colorspace;
+}
+
static GstVideoFormat
pixel_format_to_gst_format(const PixelFormat &format)
{
@@ -139,6 +279,18 @@ gst_libcamera_stream_configuration_to_caps(const StreamConfiguration &stream_cfg
"width", G_TYPE_INT, stream_cfg.size.width,
"height", G_TYPE_INT, stream_cfg.size.height,
nullptr);
+
+ if (stream_cfg.colorSpace) {
+ GstVideoColorimetry colorimetry = colorimetry_from_colorspace(stream_cfg.colorSpace.value());
+ gchar *colorimetry_str = gst_video_colorimetry_to_string(&colorimetry);
+
+ if (colorimetry_str)
+ gst_structure_set(s, "colorimetry", G_TYPE_STRING, colorimetry_str, nullptr);
+ else
+ g_error("Got invalid colorimetry from ColorSpace: %s",
+ ColorSpace::toString(stream_cfg.colorSpace).c_str());
+ }
+
gst_caps_append_structure(caps, s);
return caps;
@@ -222,6 +374,18 @@ gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg,
gst_structure_get_int(s, "height", &height);
stream_cfg.size.width = width;
stream_cfg.size.height = height;
+
+ /* Configure colorimetry */
+ if (gst_structure_has_field(s, "colorimetry")) {
+ const gchar *colorimetry_caps = gst_structure_get_string(s, "colorimetry");
+ GstVideoColorimetry colorimetry;
+
+ if(gst_video_colorimetry_from_string(&colorimetry, colorimetry_caps)) {
+ stream_cfg.colorSpace = colorspace_from_colorimetry(colorimetry);
+ } else {
+ g_critical("Invalid colorimetry %s", colorimetry_caps);
+ }
+ }
}
#if !GST_CHECK_VERSION(1, 17, 1)
--
2.31.1
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