[FFmpeg-devel] [PATCH 1/3] avcodec/avs3_parser: set has_b_frames properly

Andreas Rheinhardt andreas.rheinhardt at outlook.com
Fri May 13 12:43:44 EEST 2022


Zhao Zhili:
> has_b_frames should be output_reorder_delay field in AVS3 sequence
> header and larger than 1. The parser implementation doesn't parse
> that field. Decoder can set has_b_frames properly, so use FFMAX
> here to avoid resetting has_b_frames from output_reorder_delay to 1.
> ---
>  libavcodec/avs3_parser.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libavcodec/avs3_parser.c b/libavcodec/avs3_parser.c
> index d04d96a03a..0d2e940d1e 100644
> --- a/libavcodec/avs3_parser.c
> +++ b/libavcodec/avs3_parser.c
> @@ -114,7 +114,7 @@ static void parse_avs3_nal_units(AVCodecParserContext *s, const uint8_t *buf,
>              //            bitrate_high(12)
>              skip_bits(&gb, 32);
>  
> -            avctx->has_b_frames = !get_bits(&gb, 1);
> +            avctx->has_b_frames = FFMAX(avctx->has_b_frames, !get_bits(&gb, 1));
>  
>              avctx->framerate.num = avctx->time_base.den = ff_avs3_frame_rate_tab[ratecode].num;
>              avctx->framerate.den = avctx->time_base.num = ff_avs3_frame_rate_tab[ratecode].den;

FFMAX can evaluate its arguments more than once which is not intended here.

- Andreas


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