[FFmpeg-devel] [PATCH] avformat/utils: fix logic failure

[Carl Eugen Hoyos]

Am Di., 29. Okt. 2019 um 13:15 Uhr schrieb Paul B Mahol <onemda at gmail.com>:
>
> On 10/29/19, Michael Niedermayer <michael at niedermayer.cc> wrote:
> > On Tue, Oct 29, 2019 at 10:45:20AM +0100, Paul B Mahol wrote:
> >> Fixes decoding of wav file which is wrongly recognized as mp1 audio.
> >>
> >> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> >> ---
> >>  libavformat/utils.c | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/libavformat/utils.c b/libavformat/utils.c
> >> index cfb6d03397..bf27531ed0 100644
> >> --- a/libavformat/utils.c
> >> +++ b/libavformat/utils.c
> >> @@ -370,7 +370,7 @@ static int set_codec_from_probe_data(AVFormatContext
> >> *s, AVStream *st,
> >>                  if (fmt_id_type[i].type != AVMEDIA_TYPE_AUDIO &&
> >>                      st->codecpar->sample_rate)
> >>                      continue;
> >> -                if (st->request_probe > score &&
> >> +                if (st->request_probe > score ||
> >>                      st->codecpar->codec_id != fmt_id_type[i].id)
> >>                      continue;
> >
> > this change is wrong and would break fate,
> > the 2nd term could be removed if it causes problems but they cannot
> > be run as "||"
> >
> > how can this issue be reproduced ?
> >
>
> https://0x0.st/zYLx.wav

This repeated pcm_s16le pattern triggers the mp3 misdetection
(score 51 after 4096 bytes):

00000000  ff ff e8 ff ff ff e8 ff  ff ff e8 ff ff ff e8 ff  |................|
*

Carl Eugen