Reading some tiff images fails with "max resync size reached, could not find sync byte" error

[Arnaud]

Summary of the bug:
How to reproduce:

% ffprobe bug_tiff.tif

ffprobe version N-80012-g95b20ad Copyright (c) 2007-2016 the FFmpeg developers
  built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04)
  configuration: --enable-shared --disable-static --enable-zlib --enable-memalign-hack --disable-optimizations --disable-mmx --disable-stripping --extra-cflags=-g --extra-ldflags=-g --disable-encoder=jpeg2000 --disable-decoder=jpeg2000 --disable-doc
  libavutil      55. 24.100 / 55. 24.100
  libavcodec     57. 42.100 / 57. 42.100
  libavformat    57. 36.100 / 57. 36.100
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 45.100 /  6. 45.100
  libswscale      4.  1.100 /  4.  1.100
  libswresample   2.  0.101 /  2.  0.101
[mpegts @ 0x806aa30] max resync size reached, could not find sync byte
    Last message repeated 25 times

Latest git: ffprobe version N-80012-g95b20ad Copyright (c) 2007-2016 the FFmpeg developers

I was able to reproduce the problem with ffmpeg versions up to 2.5.

Doesn't work with ffmpeg -i either.

I'm not sure why ffmpeg needs to go through mpegts.c and more particularly mpegts_resync function: since this is a simple image file, I believe there should be no need to sync anything.

I think the image is correct though since I can open it with other software (GIMP, etc.) without any error.

[Arnaud]

tiff image not working

[Carl Eugen Hoyos]

For future tickets: Please remember not to provide ffprobe output for issues that are reproducible with ffmpeg.

[Carl Eugen Hoyos]

Regression since 296cd9c432775bbf57867fd76e8d2f505a512569 related to ticket #3939.

[Arnaud]

Thanks a lot for the quick answer :)
I wasn't able to exactly git revert commit 296cd9c432775bbf57867fd76e8d2f505a512569 because that fails, but after reverting it manually, the tiff file is now working again.

However I'm curious to know was is wrong here and how both bugs could be fixed (since obviously reverting the change will break again the problematic ts file).

Maybe something like:

return FFMAX(FFMAX((stat_all - 10*best_score)/10, 0), best_score - best_score2);

may do the trick, but I'm not sure since I don't know exactly what this code is doing.

At least it's working for my tiff file, but I haven't tested it with the ts file (not sure where to get it).

[Michael Niedermayer]

Fixed in 00c4861f13d9ec302348cfa1e2d4f1c796e9e86b