[FFmpeg-devel] [PATCH 02/14] avformat/mp3dec: Avoid calling avio_tell() multiple times

Andreas Rheinhardt andreas.rheinhardt at outlook.com
Tue Sep 14 16:17:28 EEST 2021


Andreas Rheinhardt:
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> ---
>  libavformat/mp3dec.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/libavformat/mp3dec.c b/libavformat/mp3dec.c
> index 195d89814e..9205abebc4 100644
> --- a/libavformat/mp3dec.c
> +++ b/libavformat/mp3dec.c
> @@ -171,7 +171,8 @@ static void mp3_parse_info_tag(AVFormatContext *s, AVStream *st,
>      MP3DecContext *mp3 = s->priv_data;
>      static const int64_t xing_offtbl[2][2] = {{32, 17}, {17,9}};
>      uint64_t fsize = avio_size(s->pb);
> -    fsize = fsize >= avio_tell(s->pb) ? fsize - avio_tell(s->pb) : 0;
> +    int64_t pos = avio_tell(s->pb);
> +    fsize = fsize >= pos ? fsize - pos : 0;
>  
>      /* Check for Xing / Info tag */
>      avio_skip(s->pb, xing_offtbl[c->lsf == 1][c->nb_channels == 1]);
> @@ -430,9 +431,10 @@ static int mp3_read_header(AVFormatContext *s)
>              return ret;
>      }
>  
> +    off = avio_tell(s->pb);
>      // the seek index is relative to the end of the xing vbr headers
>      for (i = 0; i < st->internal->nb_index_entries; i++)
> -        st->internal->index_entries[i].pos += avio_tell(s->pb);
> +        st->internal->index_entries[i].pos += off;
>  
>      /* the parameters will be extracted from the compressed bitstream */
>      return 0;
> 
Will apply the libavformat patches of this patchset tomorrow unless
there are objections.

- Andreas


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