[FFmpeg-devel] [PATCH 2/2] lavu/hwcontext_vaapi: add nv21 map

[wm4]

On Wed, 23 May 2018 18:29:20 +0800
Jun Zhao <mypopydev at gmail.com> wrote:

> Signed-off-by: Jun Zhao <mypopydev at gmail.com>
> ---
>  libavutil/hwcontext_vaapi.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/libavutil/hwcontext_vaapi.c b/libavutil/hwcontext_vaapi.c
> index 5bdb02f..7b3cbea 100644
> --- a/libavutil/hwcontext_vaapi.c
> +++ b/libavutil/hwcontext_vaapi.c
> @@ -100,6 +100,9 @@ static const struct {
>      enum AVPixelFormat pix_fmt;
>  } vaapi_format_map[] = {
>      MAP(NV12, YUV420,  NV12),
> +#ifdef VA_FOURCC_NV21
> +    MAP(NV21, YUV420,  NV21),    // As NV12 with U and V reversed
> +#endif
>      MAP(YV12, YUV420,  YUV420P), // With U/V planes swapped.
>      MAP(IYUV, YUV420,  YUV420P),
>  #ifdef VA_FOURCC_I420

Why does this format exist and why is it "needed"?