[FFmpeg-devel] [PATCH 3/6] Add AV_PIX_FMT_NV12T.

[wm4]

On Thu, 20 Nov 2014 17:51:54 +0100
Alexis Ballier <aballier at gentoo.org> wrote:

> This is the only format supported by MFC5 HW decoders (e.g. Samsung exynos 4412).
> ---
>  libavutil/pixdesc.c | 12 ++++++++++++
>  libavutil/pixfmt.h  |  1 +
>  2 files changed, 13 insertions(+)
> 
> diff --git a/libavutil/pixdesc.c b/libavutil/pixdesc.c
> index 648d014..426dfd4 100644
> --- a/libavutil/pixdesc.c
> +++ b/libavutil/pixdesc.c
> @@ -1900,6 +1900,18 @@ const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
>          .name = "vda",
>          .flags = AV_PIX_FMT_FLAG_HWACCEL,
>      },
> +    [AV_PIX_FMT_NV12T] = {
> +        .name = "nv12t",
> +        .nb_components = 3,
> +        .log2_chroma_w = 1,
> +        .log2_chroma_h = 1,
> +        .comp = {
> +            { 0, 0, 1, 0, 7 },        /* Y */
> +            { 1, 1, 1, 0, 7 },        /* U */
> +            { 1, 1, 2, 0, 7 },        /* V */
> +        },
> +        .flags = AV_PIX_FMT_FLAG_PLANAR,
> +    },
>  };
>  
>  static const char *color_range_names[AVCOL_RANGE_NB] = {
> diff --git a/libavutil/pixfmt.h b/libavutil/pixfmt.h
> index 756a1a7..c6709a1 100644
> --- a/libavutil/pixfmt.h
> +++ b/libavutil/pixfmt.h
> @@ -289,6 +289,7 @@ enum AVPixelFormat {
>  #if !FF_API_XVMC
>      AV_PIX_FMT_XVMC,///< XVideo Motion Acceleration via common packet passing
>  #endif /* !FF_API_XVMC */
> +    AV_PIX_FMT_NV12T,     ///< Same as NV12 except the coordinates differ: Z-shape tiled 64x32 macroblocks. V4L2 specific format corresponding to V4L2_PIX_FMT_NV12MT
>  
>      AV_PIX_FMT_NB,        ///< number of pixel formats, DO NOT USE THIS if you want to link with shared libav* because the number of formats might differ between versions
>  

I think this should be rejected. It's far too special to be useful in
general, and it's not even pixel- or line-addressable (Z-shaped tiles,
seriously?). It's pretty much a raw codec, not a pixel format.

Also, doesn't libv4l2 handle converting this to something sane
transparently?

If this is needed for the m2m filter, then maybe it should be part of
the v4l2 libavdevice.