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Subject: Re: [PATCH 4/8] media: Add P010 video format
From:   Nicolas Dufresne <nicolas@ndufresne.ca>
To:     Benjamin Gaignard <benjamin.gaignard@collabora.com>,
        hverkuil@xs4all.nl, ezequiel@collabora.com, p.zabel@pengutronix.de,
        mchehab@kernel.org, shawnguo@kernel.org, s.hauer@pengutronix.de,
        festevam@gmail.com, gregkh@linuxfoundation.org, mripard@kernel.org,
        paul.kocialkowski@bootlin.com, wens@csie.org,
        jernej.skrabec@siol.net, emil.l.velikov@gmail.com,
        andrzej.p@collabora.com, jc@kynesim.co.uk
Cc:     kernel@pengutronix.de, linux-imx@nxp.com,
        linux-media@vger.kernel.org, linux-rockchip@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Date:   Fri, 04 Jun 2021 12:17:03 -0400
In-Reply-To: <20210604130619.491200-5-benjamin.gaignard@collabora.com>
References: <20210604130619.491200-1-benjamin.gaignard@collabora.com>
         <20210604130619.491200-5-benjamin.gaignard@collabora.com>
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Le vendredi 04 juin 2021 à 15:06 +0200, Benjamin Gaignard a écrit :
> P010 is a YUV format with 10-bits per pixel with interleaved UV.
> 
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
> ---
>  .../userspace-api/media/v4l/pixfmt-yuv-planar.rst         | 8 ++++++++
>  drivers/media/v4l2-core/v4l2-common.c                     | 1 +
>  drivers/media/v4l2-core/v4l2-ioctl.c                      | 1 +
>  include/uapi/linux/videodev2.h                            | 1 +
>  4 files changed, 11 insertions(+)
> 
> diff --git a/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst b/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst
> index 090c091affd2..71fed70c03ec 100644
> --- a/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst
> +++ b/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst
> @@ -100,6 +100,13 @@ All components are stored with the same number of bits per component.
>        - Cb, Cr
>        - No
>        - 64x32 macroblocks
> +    * - V4L2_PIX_FMT_P010
> +      - 'P010'
> +      - 10
> +      - 4:2:0
> +      - Cb, Cr
> +      - No
> +      - Linear
>  
>          Horizontal Z order
>      * - V4L2_PIX_FMT_NV12MT_16X16
> @@ -171,6 +178,7 @@ horizontally.
>  .. _V4L2-PIX-FMT-NV21:
>  .. _V4L2-PIX-FMT-NV12M:
>  .. _V4L2-PIX-FMT-NV21M:
> +.. _V4L2-PIX-FMT-P010:

The NV12/21 documentation is not sufficient to describe this format. While it
shares the layout (two planes Y and interleaved UV), it does not share the
packing. In this case, assuming this is P010 (and not the P010 the Rockchip
tried to upstreamed previously), each 10bit worth of pixel data would be pakced
into 16 bits with the least significant 6 bit being padding bits.

>  
>  NV12, NV21, NV12M and NV21M
>  ---------------------------
> diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
> index 04af03285a20..37b5d82359dd 100644
> --- a/drivers/media/v4l2-core/v4l2-common.c
> +++ b/drivers/media/v4l2-core/v4l2-common.c
> @@ -266,6 +266,7 @@ const struct v4l2_format_info *v4l2_format_info(u32 format)
>  		{ .format = V4L2_PIX_FMT_NV61,    .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 2, .bpp = { 1, 2, 0, 0 }, .hdiv = 2, .vdiv = 1 },
>  		{ .format = V4L2_PIX_FMT_NV24,    .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 2, .bpp = { 1, 2, 0, 0 }, .hdiv = 1, .vdiv = 1 },
>  		{ .format = V4L2_PIX_FMT_NV42,    .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 2, .bpp = { 1, 2, 0, 0 }, .hdiv = 1, .vdiv = 1 },
> +		{ .format = V4L2_PIX_FMT_P010,    .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 2, .bpp = { 2, 2, 0, 0 }, .hdiv = 2, .vdiv = 1 },
>  
>  		{ .format = V4L2_PIX_FMT_YUV410,  .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 3, .bpp = { 1, 1, 1, 0 }, .hdiv = 4, .vdiv = 4 },
>  		{ .format = V4L2_PIX_FMT_YVU410,  .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 3, .bpp = { 1, 1, 1, 0 }, .hdiv = 4, .vdiv = 4 },
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index 2673f51aafa4..6404d5b6e350 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -1282,6 +1282,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
>  	case V4L2_PIX_FMT_NV61:		descr = "Y/CrCb 4:2:2"; break;
>  	case V4L2_PIX_FMT_NV24:		descr = "Y/CbCr 4:4:4"; break;
>  	case V4L2_PIX_FMT_NV42:		descr = "Y/CrCb 4:4:4"; break;
> +	case V4L2_PIX_FMT_P010:		descr = "10-bit Y/CrCb 4:2:0"; break;
>  	case V4L2_PIX_FMT_NV12M:	descr = "Y/CbCr 4:2:0 (N-C)"; break;
>  	case V4L2_PIX_FMT_NV21M:	descr = "Y/CrCb 4:2:0 (N-C)"; break;
>  	case V4L2_PIX_FMT_NV16M:	descr = "Y/CbCr 4:2:2 (N-C)"; break;
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 9260791b8438..e5f7acde0730 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -602,6 +602,7 @@ struct v4l2_pix_format {
>  #define V4L2_PIX_FMT_NV24    v4l2_fourcc('N', 'V', '2', '4') /* 24  Y/CbCr 4:4:4  */
>  #define V4L2_PIX_FMT_NV42    v4l2_fourcc('N', 'V', '4', '2') /* 24  Y/CrCb 4:4:4  */
>  #define V4L2_PIX_FMT_HM12    v4l2_fourcc('H', 'M', '1', '2') /*  8  YUV 4:2:0 16x16 macroblocks */
> +#define V4L2_PIX_FMT_P010    v4l2_fourcc('P', '0', '1', '0') /* 15  Y/CbCr 4:2:0 10-bit per pixel*/
>  
>  /* two non contiguous planes - one Y, one Cr + Cb interleaved  */
>  #define V4L2_PIX_FMT_NV12M   v4l2_fourcc('N', 'M', '1', '2') /* 12  Y/CbCr 4:2:0  */