"missing header" decoding mp2 after seek

[Brandon Bloom]

Summary of the bug:

FFmpeg can process the attached Fighter.mpg file, unless you try to seek. Even seeking to time zero causes the error below.

How to reproduce:

% ffmpeg -ss 0 -i Fighter.mpg out.mpg

...
[mp2 @ 0x7ff7e3001e00] Header missing
Error while decoding stream #0:1: Invalid data found when processing input
...

% ffmpeg -version
ffmpeg version 2.8.1 Copyright (c) 2000-2015 the FFmpeg developers
built with Apple LLVM version 7.0.0 (clang-700.1.76)
configuration: --prefix=/usr/local/Cellar/ffmpeg/2.8.1_1 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libvo-aacenc --enable-libxvid --enable-libfontconfig --enable-libfreetype --enable-libtheora --enable-libvorbis --enable-libvpx --enable-librtmp --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libfaac --enable-libass --enable-ffplay --enable-libssh --enable-libspeex --enable-libschroedinger --enable-libfdk-aac --enable-openssl --enable-libopus --enable-frei0r --enable-libcaca --enable-libsoxr --enable-libquvi --enable-libvidstab --enable-libx265 --enable-libwebp --enable-libzmq --enable-libbs2b --enable-libopenjpeg --disable-decoder=jpeg2000 --extra-cflags=-I/usr/local/Cellar/openjpeg/1.5.2_1/include/openjpeg-1.5 --enable-nonfree --enable-vda
libavutil      54. 31.100 / 54. 31.100
libavcodec     56. 60.100 / 56. 60.100
libavformat    56. 40.101 / 56. 40.101
libavdevice    56.  4.100 / 56.  4.100
libavfilter     5. 40.101 /  5. 40.101
libavresample   2.  1.  0 /  2.  1.  0
libswscale      3.  1.101 /  3.  1.101
libswresample   1.  2.101 /  1.  2.101
libpostproc    53.  3.100 / 53.  3.100

[Carl Eugen Hoyos]

Please test current FFmpeg git head and provide the command line that allows the reproduce your issue together with the complete, uncut console output to make this a valid ticket.

[Carl Eugen Hoyos]

If there is an issue, it is a regression since 3fa72de8 / 56ee3f9d

[Brandon Bloom]

$ ffmpeg -ss 0 -i fighter.mpg out.mpg
ffmpeg version git-2015-11-16-a62178b Copyright (c) 2000-2015 the FFmpeg developers
  built with Apple LLVM version 7.0.0 (clang-700.1.76)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/HEAD --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libvo-aacenc --enable-libxvid --enable-libfontconfig --enable-libfreetype --enable-libtheora --enable-libvorbis --enable-libvpx --enable-librtmp --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libfaac --enable-libass --enable-ffplay --enable-libssh --enable-libspeex --enable-libschroedinger --enable-libfdk-aac --enable-openssl --enable-libopus --enable-frei0r --enable-libcaca --enable-libsoxr --enable-libquvi --enable-libvidstab --enable-libx265 --enable-libwebp --enable-libzmq --enable-libbs2b --enable-libopenjpeg --disable-decoder=jpeg2000 --extra-cflags=-I/usr/local/Cellar/openjpeg/1.5.2_1/include/openjpeg-1.5 --enable-nonfree --enable-vda
  libavutil      55.  6.100 / 55.  6.100
  libavcodec     57. 15.100 / 57. 15.100
  libavformat    57. 14.100 / 57. 14.100
  libavdevice    57.  0.100 / 57.  0.100
  libavfilter     6. 15.100 /  6. 15.100
  libavresample   3.  0.  0 /  3.  0.  0
  libswscale      4.  0.100 /  4.  0.100
  libswresample   2.  0.101 /  2.  0.101
  libpostproc    54.  0.100 / 54.  0.100
Input #0, mpeg, from 'fighter.mpg':
  Duration: 00:00:14.59, start: 0.195800, bitrate: 1199 kb/s
    Stream #0:0[0x1e0]: Video: mpeg1video, yuv420p(tv), 352x240 [SAR 49:33 DAR 98:45], 1000 kb/s, 29.97 fps, 29.97 tbr, 90k tbn, 29.97 tbc
    Stream #0:1[0x1c0]: Audio: mp2, 48000 Hz, stereo, s16p, 192 kb/s
[mpeg @ 0x7f840401b800] VBV buffer size not set, using default size of 130KB
If you want the mpeg file to be compliant to some specification
Like DVD, VCD or others, make sure you set the correct buffer size
Output #0, mpeg, to 'out.mpg':
  Metadata:
    encoder         : Lavf57.14.100
    Stream #0:0: Video: mpeg1video, yuv420p, 352x240 [SAR 49:33 DAR 98:45], q=2-31, 200 kb/s, 29.97 fps, 90k tbn, 29.97 tbc
    Metadata:
      encoder         : Lavc57.15.100 mpeg1video
    Stream #0:1: Audio: mp2, 48000 Hz, stereo, s16, 384 kb/s
    Metadata:
      encoder         : Lavc57.15.100 mp2
Stream mapping:
  Stream #0:0 -> #0:0 (mpeg1video (native) -> mpeg1video (native))
  Stream #0:1 -> #0:1 (mp2 (native) -> mp2 (native))
Press [q] to stop, [?] for help
[mp2 @ 0x7f8404008600] Header missing
Error while decoding stream #0:1: Invalid data found when processing input
frame=  437 fps=0.0 q=11.6 Lsize=    1134kB time=00:00:14.60 bitrate= 636.0kbits/s    
video:440kB audio:680kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.326246%

[Brandon Bloom]

Hi there, I updated this ticket 2 weeks ago with the requested log data build on master at a62178b. I apologize for the bump email, but I noticed that the component changed from "new" to "undetermined" and wasn't sure if that meant that this would accidentally fall in to a blackhole. If I missed some part of the documented process, please link me to it and I'll try to meet the requirements for getting this noticed. Thanks!

[Carl Eugen Hoyos]

Could you explain a little better what the issue with the output file is?
(The component is never set to "new", this setting does not exist for "Component".)

Very generally, if you want an issue fixed, send a patch to the development mailing list.

[Brandon Bloom]

The issue is that no output file is generated. Encoding fails completely.

[Carl Eugen Hoyos]

The console output you provided indicates that an output file of 1134kB was written.

[Brandon Bloom]

My apologies, closing this ticket.

For some reason I recalled no output being created at all. Maybe that was an older FFmpeg version, or maybe it was my imagination. Either way, this is working fine for me now both on the command line, and with some additional error handling code calling the APIs directly.