[FFmpeg-devel] [PATCH v3] libavcodec/cbs_av1: Add size check before parse obu

Xiang, Haihao haihao.xiang at intel.com
Wed Sep 21 11:27:29 EEST 2022


> cbs_av1_write_unit() check pbc size after parsing obu frame, and return

It is cbs_av1_write_obu(), not cbs_av1_write_unit(), right ? 

Thanks
Haihao


> AVERROR(ENOSPC) if pbc is small. pbc will be reallocated and this obu
> frame will be parsed again, but this may cause error because
> CodedBitstreamAV1Context has already been updated, for example
> ref_order_hint is updated and will not match the same obu frame. Now size
> check is added before parsing obu frame to avoid this error.
> 
> Signed-off-by: Wenbin Chen <wenbin.chen at intel.com>
> ---
>  libavcodec/cbs_av1.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/libavcodec/cbs_av1.c b/libavcodec/cbs_av1.c
> index 154d9156cf..9c51a8c7c8 100644
> --- a/libavcodec/cbs_av1.c
> +++ b/libavcodec/cbs_av1.c
> @@ -1075,6 +1075,9 @@ static int cbs_av1_write_obu(CodedBitstreamContext *ctx,
>          put_bits32(pbc, 0);
>      }
>  
> +    if (8 * (unit->data_size + obu->obu_size) > put_bits_left(pbc))
> +        return AVERROR(ENOSPC);
> +
>      td = NULL;
>      start_pos = put_bits_count(pbc);
>  


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