[FFmpeg-devel] [PATCH] libavcodec/h264dec: export block type in H.264

[Mark Thompson]

On 15/07/2020 22:05, Yongle Lin wrote:
> ---
>   libavcodec/h264dec.c | 14 ++++++++++++++
>   1 file changed, 14 insertions(+)
> 
> diff --git a/libavcodec/h264dec.c b/libavcodec/h264dec.c
> index 1e2ca68449..b3de5290d0 100644
> --- a/libavcodec/h264dec.c
> +++ b/libavcodec/h264dec.c
> @@ -816,6 +816,20 @@ static int h264_export_enc_params(AVFrame *f, H264Picture *p)
>               b->h     = 16;
>   
>               b->delta_qp = p->qscale_table[mb_xy] - par->qp;
> +
> +            int mb_type = p->mb_type[mb_xy];
> +            if (IS_PCM(mb_type))
> +                b->flags |= AV_VIDEO_ENC_BLOCK_INTRA;

Can you explain your definition of what makes a block "intra"?  If you really do mean to only include PCM blocks then maybe it should have a different name, because that isn't what I would expect.

> +            if (IS_SKIP(mb_type))
> +                b->flags |= AV_VIDEO_ENC_BLOCK_SKIP; > +            if (!USES_LIST(mb_type, 1))
> +                b->ref[0] = p->ref_index[0];
> +            else if (!USES_LIST(mb_type, 0))
> +                b->ref[0] = p->ref_index[1];
> +            else {
> +                b->ref[0] = p->ref_index[0];
> +                b->ref[1] = p->ref_index[1];

I don't think ref_index is anything to do with what you think it is.

Also note that code of this form must be insufficient due to the lack dependence on both the slice and the block.  (Slice headers define the two reference picture lists, and blocks within a slice 
choose pictures from those lists.)

> +            }
>           }
>   
>       return 0;
> 

- Mark