Re: [PATCH 05/10] media: Add B312 video format

[Hans Verkuil <hverkuil-cisco@xs4all.nl>]

On 20/12/2022 04:11, Ming Qian wrote:
> B312 is a reversed RGB format with 12 bits per component like BGR24,
> expanded to 16bits.
> Data in the 12 high bits, zeros in the 4 low bits,
> arranged in little endian order.
> 
> Signed-off-by: Ming Qian <ming.qian@nxp.com>
> ---
>  .../userspace-api/media/v4l/pixfmt-rgb.rst    | 35 +++++++++++++++++++
>  drivers/media/v4l2-core/v4l2-common.c         |  1 +
>  drivers/media/v4l2-core/v4l2-ioctl.c          |  1 +
>  include/uapi/linux/videodev2.h                |  3 ++
>  4 files changed, 40 insertions(+)
> 
> diff --git a/Documentation/userspace-api/media/v4l/pixfmt-rgb.rst b/Documentation/userspace-api/media/v4l/pixfmt-rgb.rst
> index 30f51cd33f99..f7785c93292a 100644
> --- a/Documentation/userspace-api/media/v4l/pixfmt-rgb.rst
> +++ b/Documentation/userspace-api/media/v4l/pixfmt-rgb.rst
> @@ -763,6 +763,41 @@ nomenclature that instead use the order of components as seen in a 24- or
>      \normalsize
>  
>  
> +More Than 8 Bits Per Component
> +==============================
> +
> +These formats store an RGB triplet in six or eighth bytes, with more than 8 bits per component.
> +expand the bits per component to 16 bits, data in the high bits, zeros in the low bits,
> +arranged in little endian order.
> +
> +.. raw:: latex
> +
> +    \small
> +
> +.. flat-table:: RGB Formats With More Than 8 Bits Per Component
> +    :header-rows:  1
> +    :stub-columns: 0
> +
> +    * - Identifier
> +      - Code
> +      - Byte 1-0
> +      - Byte 3-2
> +      - Byte 5-4
> +      - Byte 7-6
> +    * .. _V4L2-PIX-FMT-B312:
> +
> +      - ``V4L2_PIX_FMT_B312``
> +      - 'B312'
> +
> +      - B\ :sub:`15-4`
> +      - G\ :sub:`15-4`
> +      - R\ :sub:`15-4`
> +      -
> +
> +.. raw:: latex
> +
> +    \normalsize
> +
>  Deprecated RGB Formats
>  ======================
>  
> diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
> index 332d4b11bc1b..0cc58abae562 100644
> --- a/drivers/media/v4l2-core/v4l2-common.c
> +++ b/drivers/media/v4l2-core/v4l2-common.c
> @@ -252,6 +252,7 @@ const struct v4l2_format_info *v4l2_format_info(u32 format)
>  		{ .format = V4L2_PIX_FMT_RGB565,  .pixel_enc = V4L2_PIXEL_ENC_RGB, .mem_planes = 1, .comp_planes = 1, .bpp = { 2, 0, 0, 0 }, .hdiv = 1, .vdiv = 1 },
>  		{ .format = V4L2_PIX_FMT_RGB555,  .pixel_enc = V4L2_PIXEL_ENC_RGB, .mem_planes = 1, .comp_planes = 1, .bpp = { 2, 0, 0, 0 }, .hdiv = 1, .vdiv = 1 },
>  		{ .format = V4L2_PIX_FMT_BGR666,  .pixel_enc = V4L2_PIXEL_ENC_RGB, .mem_planes = 1, .comp_planes = 1, .bpp = { 4, 0, 0, 0 }, .hdiv = 1, .vdiv = 1 },
> +		{ .format = V4L2_PIX_FMT_B312,    .pixel_enc = V4L2_PIXEL_ENC_RGB, .mem_planes = 1, .comp_planes = 1, .bpp = { 6, 0, 0, 0 }, .hdiv = 1, .vdiv = 1 },
>  
>  		/* YUV packed formats */
>  		{ .format = V4L2_PIX_FMT_YUYV,    .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 1, .bpp = { 2, 0, 0, 0 }, .hdiv = 2, .vdiv = 1 },
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index 5b97d7e5dbbf..8c3d40d3acf5 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -1298,6 +1298,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
>  	case V4L2_PIX_FMT_BGRX32:	descr = "32-bit XBGR 8-8-8-8"; break;
>  	case V4L2_PIX_FMT_RGBA32:	descr = "32-bit RGBA 8-8-8-8"; break;
>  	case V4L2_PIX_FMT_RGBX32:	descr = "32-bit RGBX 8-8-8-8"; break;
> +	case V4L2_PIX_FMT_B312:		descr = "12-bit Depth BGR"; break;
>  	case V4L2_PIX_FMT_GREY:		descr = "8-bit Greyscale"; break;
>  	case V4L2_PIX_FMT_Y4:		descr = "4-bit Greyscale"; break;
>  	case V4L2_PIX_FMT_Y6:		descr = "6-bit Greyscale"; break;
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 3475331737af..c67f895210de 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -577,6 +577,9 @@ struct v4l2_pix_format {
>  #define V4L2_PIX_FMT_ARGB32  v4l2_fourcc('B', 'A', '2', '4') /* 32  ARGB-8-8-8-8  */
>  #define V4L2_PIX_FMT_XRGB32  v4l2_fourcc('B', 'X', '2', '4') /* 32  XRGB-8-8-8-8  */
>  
> +/* RGB formats (6 or 8 bytes per pixel) */
> +#define V4L2_PIX_FMT_B312    v4l2_fourcc('B', '3', '1', '2') /* 48  BGR 12-bit per component */

BGR24_12

Regards,

	Hans

> +
>  /* Grey formats */
>  #define V4L2_PIX_FMT_GREY    v4l2_fourcc('G', 'R', 'E', 'Y') /*  8  Greyscale     */
>  #define V4L2_PIX_FMT_Y4      v4l2_fourcc('Y', '0', '4', ' ') /*  4  Greyscale     */