[FFmpeg-devel] [PATCH 1/1] cbs_h264: Fix handling of auxiliary pictures

[Mark Thompson]

On 07/11/18 03:47, Andreas Rheinhardt wrote:
> The earlier code used the most recent non-auxiliary slice to determine
> whether an auxiliary slice has the syntax of an IDR slice, even when
> the most recent slice was from a slice of a redundant frame. Now only
> slices of the primary coded picture are used, as the specifications
> mandate.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at googlemail.com>
> ---
>  libavcodec/cbs_h264_syntax_template.c | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/libavcodec/cbs_h264_syntax_template.c b/libavcodec/cbs_h264_syntax_template.c
> index dbf9ff1268..aaa4589f4d 100644
> --- a/libavcodec/cbs_h264_syntax_template.c
> +++ b/libavcodec/cbs_h264_syntax_template.c
> @@ -1190,11 +1190,10 @@ static int FUNC(slice_header)(CodedBitstreamContext *ctx, RWContext *rw,
>                     "in the same access unit.\n");
>              return AVERROR_INVALIDDATA;
>          }
> -    } else {
> -        h264->last_slice_nal_unit_type =
> -            current->nal_unit_header.nal_unit_type;
> -    }
> -    idr_pic_flag = h264->last_slice_nal_unit_type == H264_NAL_IDR_SLICE;
> +        idr_pic_flag = h264->last_slice_nal_unit_type == H264_NAL_IDR_SLICE;
> +    } else
> +        idr_pic_flag = current->nal_unit_header.nal_unit_type == H264_NAL_IDR_SLICE;
> +
>  
>      ue(first_mb_in_slice, 0, H264_MAX_MB_PIC_SIZE - 1);
>      ue(slice_type, 0, 9);
> @@ -1272,6 +1271,13 @@ static int FUNC(slice_header)(CodedBitstreamContext *ctx, RWContext *rw,
>  
>      if (pps->redundant_pic_cnt_present_flag)
>          ue(redundant_pic_cnt, 0, 127);
> +    else
> +        infer(redundant_pic_cnt, 0);
> +
> +    if (current->nal_unit_header.nal_unit_type != H264_NAL_AUXILIARY_SLICE
> +        && !current->redundant_pic_cnt)
> +        h264->last_slice_nal_unit_type =
> +            current->nal_unit_header.nal_unit_type;
>  
>      if (slice_type_b)
>          flag(direct_spatial_mv_pred_flag);
> 

Yep; LGTM, and applied.

Thanks!

- Mark