[libcamera-devel] [PATCH v1 1/5] gstreamer: Convert form colorspace to colorimetry.

[Vedant Paranjape]

Hello Rishikesh,

Thanks for the patch.

Subject line can be better as suggested by Nicolas:

gstreamer: convert from GStreamer to libcamera colorspace

On Sun, Jul 3, 2022 at 9:34 AM Rishikesh Donadkar <
rishikeshdonadkar at gmail.com> wrote:

> Libcamera StreamConfiguration class has colorSpace attribute, which
> holds the colorspace that is being applied to the camera after the
> validation of the camera configuration.
>
> Map between the libcamera colorspace and GStreamer colorimetry and find
> the closest colorimetry corresponding to the colorspace in stream
> configuration.
>

s/Map between the libcamera colorspace and GStreamer colorimetr/Map the
libcamera colorspace to GStreamer colorimetry.


> Signed-off-by: Rishikesh Donadkar <rishikeshdonadkar at gmail.com>
> ---
>  src/gstreamer/gstlibcamera-utils.cpp | 71 ++++++++++++++++++++++++++++
>  1 file changed, 71 insertions(+)
>
> diff --git a/src/gstreamer/gstlibcamera-utils.cpp
> b/src/gstreamer/gstlibcamera-utils.cpp
> index 3f242286..20c39919 100644
> --- a/src/gstreamer/gstlibcamera-utils.cpp
> +++ b/src/gstreamer/gstlibcamera-utils.cpp
> @@ -45,6 +45,34 @@ static struct {
>         /* \todo NV42 is used in libcamera but is not mapped in GStreamer
> yet. */
>  };
>
> +static const std::vector<std::pair<ColorSpace, std::string>>
> ColorSpaceTocolorimetry = {
> +       { ColorSpace::Srgb, GST_VIDEO_COLORIMETRY_SRGB },
> +       { ColorSpace::Rec709, GST_VIDEO_COLORIMETRY_BT709 },
> +       { ColorSpace::Rec2020, GST_VIDEO_COLORIMETRY_BT2020 },
> +};
> +
> +static const std::map<ColorSpace::Primaries, GstVideoColorPrimaries>
> ToGstVideoColorPrimaries = {
> +       { ColorSpace::Primaries::Smpte170m,
> GST_VIDEO_COLOR_PRIMARIES_SMPTE170M },
> +       { ColorSpace::Primaries::Rec709, GST_VIDEO_COLOR_PRIMARIES_BT709 },
> +       { ColorSpace::Primaries::Rec2020, GST_VIDEO_COLOR_PRIMARIES_BT2020
> },
> +};
> +
> +static const std::map<ColorSpace::TransferFunction,
> GstVideoTransferFunction> ToGstVideoTransferFunction = {
> +       { ColorSpace::TransferFunction::Srgb, GST_VIDEO_TRANSFER_SRGB },
> +       { ColorSpace::TransferFunction::Rec709, GST_VIDEO_TRANSFER_BT709 },
> +};
> +
> +static const std::map<ColorSpace::YcbcrEncoding, GstVideoColorMatrix>
> ToGstVideoColorMatrix = {
> +       { ColorSpace::YcbcrEncoding::Rec601, GST_VIDEO_COLOR_MATRIX_BT601
> },
> +       { ColorSpace::YcbcrEncoding::Rec709, GST_VIDEO_COLOR_MATRIX_BT709
> },
> +       { ColorSpace::YcbcrEncoding::Rec2020,
> GST_VIDEO_COLOR_MATRIX_BT2020 },
> +};
> +
> +static const std::map<ColorSpace::Range, GstVideoColorRange>
> ToGstVideoColorRange = {
> +       { ColorSpace::Range::Full, GST_VIDEO_COLOR_RANGE_0_255 },
> +       { ColorSpace::Range::Limited, GST_VIDEO_COLOR_RANGE_16_235 },
> +};
> +
>  static GstVideoFormat
>  pixel_format_to_gst_format(const PixelFormat &format)
>  {
> @@ -87,6 +115,49 @@ bare_structure_from_format(const PixelFormat &format)
>         }
>  }
>
> +static const gchar *
> +colorimerty_from_colorspace(std::optional<ColorSpace> colorSpace)
> +{
> +       const gchar *colorimetry_str;
> +       GstVideoColorimetry colorimetry;
> +
> +       auto iterColorimetry =
> std::find_if(ColorSpaceTocolorimetry.begin(), ColorSpaceTocolorimetry.end(),
> +                                           [&colorSpace](const auto
> &item) {
> +                                                   return colorSpace ==
> item.first;
> +                                           });
> +       if (iterColorimetry != ColorSpaceTocolorimetry.end()) {
> +               colorimetry_str = (gchar *)iterColorimetry->second.c_str();
> +               return colorimetry_str;
> +       }
> +
> +       auto iterPrimaries =
> ToGstVideoColorPrimaries.find(colorSpace->primaries);
> +       if (iterPrimaries != ToGstVideoColorPrimaries.end())
> +               colorimetry.primaries = iterPrimaries->second;
> +       else
> +               colorimetry.primaries = GST_VIDEO_COLOR_PRIMARIES_UNKNOWN;
> +
> +       auto iterTransferFunction =
> ToGstVideoTransferFunction.find(colorSpace->transferFunction);
> +       if (iterTransferFunction != ToGstVideoTransferFunction.end())
> +               colorimetry.transfer = iterTransferFunction->second;
> +       else
> +               colorimetry.transfer = GST_VIDEO_TRANSFER_UNKNOWN;
> +
> +       auto iterYcbcrEncoding =
> ToGstVideoColorMatrix.find(colorSpace->ycbcrEncoding);
> +       if (iterYcbcrEncoding != ToGstVideoColorMatrix.end())
> +               colorimetry.matrix = iterYcbcrEncoding->second;
> +       else
> +               colorimetry.matrix = GST_VIDEO_COLOR_MATRIX_UNKNOWN;
> +
> +       auto iterRange = ToGstVideoColorRange.find(colorSpace->range);
> +       if (iterRange != ToGstVideoColorRange.end())
> +               colorimetry.range = iterRange->second;
> +       else
> +               colorimetry.range = GST_VIDEO_COLOR_RANGE_UNKNOWN;
> +
> +       colorimetry_str = gst_video_colorimetry_to_string(&colorimetry);
> +       return colorimetry_str;
> +}
> +
>  GstCaps *
>  gst_libcamera_stream_formats_to_caps(const StreamFormats &formats)
>  {
> --
> 2.25.1
>
>
Regards,
Vedant Paranjape
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