[libcamera-devel] [PATCH] libcamera: v4l2_subdevice: Add JPEG_1X8 and BGR888_1X24 mbus formats to formatInfoMap

[Jacopo Mondi]

Hi Xavier

On Mon, Oct 10, 2022 at 11:22:56AM +0200, Xavier Roumegue (OSS) via libcamera-devel wrote:
> From: Xavier Roumegue <xavier.roumegue at oss.nxp.com>
>
> The warnings "Unknown subdev format 0x4001, defaulting to RGB encoding" and
> "Unknown subdev format 0x1013, defaulting to RGB encoding" are thrown while using
> simple pipeline handler with NXP ISI hardware.
> The JPEG_1X8 and BGR888_1X24 media bus formats, supported by the ISI driver, are
> missing in the V4L2SubdeviceFormatInfo structure storing the correspondence
> between a media bus format and a colour encoding. So populate the structure with
> the missing media bus formats.
>
> Signed-off-by: Xavier Roumegue <xavier.roumegue at oss.nxp.com>

Just to point out that for JPEG, the entries we have in the main
formats map, report YUV as color encoding

src/libcamera/formats.cpp-      /* Compressed formats. */
src/libcamera/formats.cpp-      { formats::MJPEG, {
src/libcamera/formats.cpp-              .name = "MJPEG",
src/libcamera/formats.cpp-              .format = formats::MJPEG,
src/libcamera/formats.cpp-              .v4l2Formats = {
src/libcamera/formats.cpp-                      V4L2PixelFormat(V4L2_PIX_FMT_MJPEG),
src/libcamera/formats.cpp:                      V4L2PixelFormat(V4L2_PIX_FMT_JPEG),
src/libcamera/formats.cpp-              },
src/libcamera/formats.cpp-              .bitsPerPixel = 0,
src/libcamera/formats.cpp-              .colourEncoding = PixelFormatInfo::ColourEncodingYUV,
src/libcamera/formats.cpp-              .packed = false,
src/libcamera/formats.cpp-              .pixelsPerGroup = 1,
src/libcamera/formats.cpp-              .planes = {{ { 1, 1 }, { 0, 0 }, { 0, 0 } }},
src/libcamera/formats.cpp-      } },

Unfortunately the kernel documentation for the format doesn't help
much:

https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/subdev-formats.html?highlight=media_bus_fmt_jpeg_1x8
> ---
>  src/libcamera/v4l2_subdevice.cpp | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/src/libcamera/v4l2_subdevice.cpp b/src/libcamera/v4l2_subdevice.cpp
> index 9ef95963..f34eea24 100644
> --- a/src/libcamera/v4l2_subdevice.cpp
> +++ b/src/libcamera/v4l2_subdevice.cpp
> @@ -68,6 +68,7 @@ const std::map<uint32_t, V4L2SubdeviceFormatInfo> formatInfoMap = {
>  	{ MEDIA_BUS_FMT_RGB565_2X8_LE, { 16, "RGB565_2X8_LE", PixelFormatInfo::ColourEncodingRGB } },
>  	{ MEDIA_BUS_FMT_RGB666_1X18, { 18, "RGB666_1X18", PixelFormatInfo::ColourEncodingRGB } },
>  	{ MEDIA_BUS_FMT_RGB888_1X24, { 24, "RGB888_1X24", PixelFormatInfo::ColourEncodingRGB } },
> +	{ MEDIA_BUS_FMT_BGR888_1X24, { 24, "BGR888_1X24", PixelFormatInfo::ColourEncodingRGB } },
>  	{ MEDIA_BUS_FMT_RGB888_2X12_BE, { 24, "RGB888_2X12_BE", PixelFormatInfo::ColourEncodingRGB } },
>  	{ MEDIA_BUS_FMT_RGB888_2X12_LE, { 24, "RGB888_2X12_LE", PixelFormatInfo::ColourEncodingRGB } },
>  	{ MEDIA_BUS_FMT_ARGB8888_1X32, { 32, "ARGB8888_1X32", PixelFormatInfo::ColourEncodingRGB } },
> @@ -133,6 +134,7 @@ const std::map<uint32_t, V4L2SubdeviceFormatInfo> formatInfoMap = {
>  	{ MEDIA_BUS_FMT_SRGGB12_1X12, { 12, "SRGGB12_1X12", PixelFormatInfo::ColourEncodingRAW } },
>  	/* \todo Clarify colour encoding for HSV formats */
>  	{ MEDIA_BUS_FMT_AHSV8888_1X32, { 32, "AHSV8888_1X32", PixelFormatInfo::ColourEncodingRGB } },
> +	{ MEDIA_BUS_FMT_JPEG_1X8, { 8, "JPEG_1X8", PixelFormatInfo::ColourEncodingRGB } },
>  };
>
>  } /* namespace */
> --
> 2.37.3
>