[FFmpeg-trac] #3443(avcodec:open): h264_mp4toannexb filter causes artefacts

[FFmpeg]

#3443: h264_mp4toannexb filter causes artefacts
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             Reporter:  eelco       |                    Owner:
                 Type:  defect      |                   Status:  open
             Priority:  normal      |                Component:  avcodec
              Version:  git-master  |               Resolution:
             Keywords:  h264        |               Blocked By:
             Blocking:              |  Reproduced by developer:  1
Analyzed by developer:  0           |
------------------------------------+-----------------------------------
Changes (by cehoyos):

 * keywords:   => h264
 * status:  new => open
 * component:  undetermined => avcodec
 * reproduced:  0 => 1


Comment:

 Replying to [ticket:3443 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.

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Ticket URL: <https://trac.ffmpeg.org/ticket/3443#comment:4>
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