[FFmpeg-cvslog] lavf: if id3v2 tag is present and all else fails, guess by file extension

[Reimar Döffinger]

On 7 Apr 2011, at 03:43, git at videolan.org (Anton Khirnov) wrote:

> ffmpeg | branch: master | Anton Khirnov <anton at khirnov.net> | Tue Apr  5 12:19:35 2011 +0200| [56a1000917694b2277064c5573b0dd818ad7a379] | committer: Anton Khirnov
> 
> lavf: if id3v2 tag is present and all else fails, guess by file extension
> 
>> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=56a1000917694b2277064c5573b0dd818ad7a379
> ---
> 
> libavformat/utils.c |   13 ++++++++++++-
> 1 files changed, 12 insertions(+), 1 deletions(-)
> 
> diff --git a/libavformat/utils.c b/libavformat/utils.c
> index 31eddec..a5d4a6f 100644
> --- a/libavformat/utils.c
> +++ b/libavformat/utils.c
> @@ -371,7 +371,7 @@ AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score
> {
>     AVProbeData lpd = *pd;
>     AVInputFormat *fmt1 = NULL, *fmt;
> -    int score;
> +    int score, id3 = 0;
> 
>     if (lpd.buf_size > 10 && ff_id3v2_match(lpd.buf, ID3v2_DEFAULT_MAGIC)) {
>         int id3len = ff_id3v2_tag_len(lpd.buf);
> @@ -379,6 +379,7 @@ AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score
>             lpd.buf += id3len;
>             lpd.buf_size -= id3len;
>         }
> +        id3 = 1;
>     }
> 
>     fmt = NULL;
> @@ -399,6 +400,16 @@ AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score
>         }else if (score == *score_max)
>             fmt = NULL;
>     }
> +
> +    /* a hack for files with huge id3v2 tags -- try to guess by file extension. */
> +    if (!fmt && id3 && *score_max < AVPROBE_SCORE_MAX/4) {
> +        while ((fmt = av_iformat_next(fmt)))
> +            if (fmt->extensions && av_match_ext(lpd.filename, fmt->extensions)) {
> +                *score_max = AVPROBE_SCORE_MAX/4;
> +                break;
> +            }

It seems unreasonable to override even scores of max/4 - 1, and max/4 sure is very high for a value based on nothing but extension!