[FFmpeg-devel] [FFmpeg-cvslog] lavf/amr: Make the heuristic for auto-detection even stricter.

[Michael Niedermayer]

On Mon, Jun 25, 2018 at 11:22:31PM +0200, Carl Eugen Hoyos wrote:
> 2018-06-23 14:43 GMT+02:00, Michael Niedermayer <michael at niedermayer.cc>:
> > On Thu, Jun 21, 2018 at 10:09:14PM +0000, Carl Eugen Hoyos wrote:
> >> ffmpeg | branch: master | Carl Eugen Hoyos <ceffmpeg at gmail.com> | Fri Jun
> >> 22 00:08:13 2018 +0200| [40b7e6071815fc416a4efc5dc1616f5460a3aacb] |
> >> committer: Carl Eugen Hoyos
> >>
> >> lavf/amr: Make the heuristic for auto-detection even stricter.
> >>
> >> Fixes ticket #7270.
> >>
> >> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=40b7e6071815fc416a4efc5dc1616f5460a3aacb
> >> ---
> >>
> >>  libavformat/amr.c | 6 +++---
> >>  1 file changed, 3 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/libavformat/amr.c b/libavformat/amr.c
> >> index f954803d46..6cc06bceac 100644
> >> --- a/libavformat/amr.c
> >> +++ b/libavformat/amr.c
> >> @@ -201,7 +201,7 @@ static int amrnb_probe(AVProbeData *p)
> >>              i++;
> >>          }
> >>      }
> >> -    if (valid > 100 && valid > invalid)
> >> +    if (valid > 100 && valid >> 4 > invalid)
> >>          return AVPROBE_SCORE_EXTENSION / 2 + 1;
> >>      return 0;
> >>  }
> >> @@ -258,8 +258,8 @@ static int amrwb_probe(AVProbeData *p)
> >>              i++;
> >>          }
> >>      }
> >> -    if (valid > 100 && valid > invalid)
> >> -        return AVPROBE_SCORE_EXTENSION / 2 - 1;
> >> +    if (valid > 100 && valid >> 4 > invalid)
> >> +        return AVPROBE_SCORE_EXTENSION / 2 + 1;
> >
> > This breaks detecting the h263 file:
> >
> > https://samples.ffmpeg.org/V-codecs/h263/h263-raw/messenger.h263
> 
> Attached patch fixes the existing heuristic to avoid detection of files
> like this one.
> 
> Sorry, Carl Eugen

>  amr.c |    6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 4b51c43bba3a8a286dc8d8239936d615ab733ec5  0001-lavf-amr-Fix-heuristic-to-avoid-detection-of-repeate.patch
> From 3bfac3c9a525e8ce92c025ee2853a600d71e64d5 Mon Sep 17 00:00:00 2001
> From: Carl Eugen Hoyos <ceffmpeg at gmail.com>
> Date: Mon, 25 Jun 2018 23:20:09 +0200
> Subject: [PATCH] lavf/amr: Fix heuristic to avoid detection of repeated
>  bytes.

LGTM

thx

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The bravest are surely those who have the clearest vision
of what is before them, glory and danger alike, and yet
notwithstanding go out to meet it. -- Thucydides
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