h264_mp4toannexb filter causes artefacts

[eelco]

When copying a h.264 stream to a TS file, the result does not play cleanly but contains several artefacts. This only happens for certain input.

How to reproduce:

$ ffmpeg -i input.m4v -c:a copy -c:v copy -bsf h264_mp4toannexb copied.ts
ffmpeg version N-61143-g64e4bd7 Copyright (c) 2000-2014 the FFmpeg developers
  built on Mar  7 2014 10:57:23 with Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)
  configuration: --prefix=/Users/eelco/Projects/Beamer/FFmpeg/build/ --disable-ffserver --disable-doc --extra-cflags='-DMACOSX_DEPLOYMENT_TARGET=10.9 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk -mmacosx-version-min=10.9 -I/Users/eelco/Projects/Beamer/FFmpeg/build//include' --extra-ldflags='-isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk -mmacosx-version-min=10.9 -L/Users/eelco/Projects/Beamer/FFmpeg/build//lib'
  libavutil      52. 66.101 / 52. 66.101
  libavcodec     55. 52.102 / 55. 52.102
  libavformat    55. 33.101 / 55. 33.101
  libavdevice    55. 11.100 / 55. 11.100
  libavfilter     4.  3.100 /  4.  3.100
  libswscale      2.  5.101 /  2.  5.101
  libswresample   0. 18.100 /  0. 18.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.m4v':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42isomavc1
    creation_time   : 2014-03-04 16:07:22
    title           : American Hustle t03 - iFlix
    encoder         : iFlicks 2.0.2.2166
    hd_video        : 1
    media_type      : 9
    gapless_playback: 0
  Duration: 00:03:26.34, start: 0.000021, bitrate: 17699 kb/s
    Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 17535 kb/s, 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
    Metadata:
      creation_time   : 2014-03-04 16:07:22
    Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 156 kb/s (default)
    Metadata:
      creation_time   : 2014-03-04 16:07:22
File 'copied.ts' already exists. Overwrite ? [y/N] y
Output #0, mpegts, to 'copied.ts':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42isomavc1
    gapless_playback: 0
    title           : American Hustle t03 - iFlix
    media_type      : 9
    hd_video        : 1
    encoder         : Lavf55.33.101
    Stream #0:0(eng): Video: h264 (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 17535 kb/s, 23.98 fps, 90k tbn, 23.98 tbc (default)
    Metadata:
      creation_time   : 2014-03-04 16:07:22
    Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, 156 kb/s (default)
    Metadata:
      creation_time   : 2014-03-04 16:07:22
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
Press [q] to stop, [?] for help
[adts @ 0x7fdb12809800] Encoder did not produce proper pts, making some up.
frame= 4947 fps=573 q=-1.0 Lsize=  481239kB time=00:03:26.33 bitrate=19106.3kbits/s    
video:441654kB audio:3940kB subtitle:0 data:0 global headers:0kB muxing overhead 7.999454%

Note that the input file is already problematic for some players.

player	input	copied
ffplay	incorrect framerate	artefacts and incorrect framerate
QuickTime Player	no problems	artefacts
MplayerX	garbled	artefacts

[eelco]

Input and output files are uploaded to upload.ffmpeg.org as 3443-input.m4v and 3443-copied.ts respectively.

To be clear, I’m suspecting h264_mp4toannexb to be the cause of this because transcoding the video (e.g., ffmpeg -i input.m4v -c:a copy -c:v libx264 transcoded.mp4) works as expected.

[Carl Eugen Hoyos]

I cannot find the (necessary) input file, could you upload it again?
Output files are typically unneeded.

[eelco]

Oops, sorry, it failed. It should be uploaded in 20 minutes or so.

[Carl Eugen Hoyos]

Replying to eelco:

player	input
ffplay	incorrect framerate

Unrelated to your ticket (that is reproducible):
The file 3443-input.m4v that you uploaded plays in-sync here with ffplay and the frame-rate looks expected. What do I miss?

The problem that remuxing the h264 stream of the mp4 sample with the h264_mp4toannexb bitstream filter leads to massive artefacts is reproducible, not a regression afaict. I have remuxed the beginning of the sample to mp4 and the resulting file allows to reproduce the issue here:

$ ffmpeg -i 3443-input_remux.m4v -vcodec copy -vbsf h264_mp4toannexb out.h264
ffmpeg version N-61143-g64e4bd7 Copyright (c) 2000-2014 the FFmpeg developers
  built on Mar  7 2014 10:48:59 with gcc 4.7 (SUSE Linux)
  configuration: --enable-gpl --enable-libvorbis --enable-libvpx
  libavutil      52. 66.101 / 52. 66.101
  libavcodec     55. 52.102 / 55. 52.102
  libavformat    55. 33.101 / 55. 33.101
  libavdevice    55. 11.100 / 55. 11.100
  libavfilter     4.  3.100 /  4.  3.100
  libswscale      2.  5.101 /  2.  5.101
  libswresample   0. 18.100 /  0. 18.100
  libpostproc    52.  3.100 / 52.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '3443-input_remux.m4v':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    title           : American Hustle t03 - iFlix
    encoder         : Lavf55.33.101
    media_type      : 9
    hd_video        : 1
    gapless_playback: 0
  Duration: 00:00:02.00, start: 0.000000, bitrate: 9642 kb/s
    Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 9635 kb/s, 23.99 fps, 23.98 tbr, 16k tbn, 47.95 tbc (default)
    Metadata:
      handler_name    : VideoHandler
Output #0, h264, to 'out.h264':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    title           : American Hustle t03 - iFlix
    gapless_playback: 0
    media_type      : 9
    hd_video        : 1
    encoder         : Lavf55.33.101
    Stream #0:0(eng): Video: h264 (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 9635 kb/s, 23.99 fps, 90k tbn, 23.98 tbc (default)
    Metadata:
      handler_name    : VideoHandler
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
frame=   48 fps=0.0 q=-1.0 Lsize=    2354kB time=00:00:01.91 bitrate=10055.2kbits/s
video:2354kB audio:0kB subtitle:0 data:0 global headers:0kB muxing overhead 0.006970%

out.h264 shows massive artefacts on playback.

[eelco]

Sorry, I used an older version of ffplay (not from the same build), so that’s probably my fault.

[eelco]

Seems to be fixed in 289b149cec, thanks!