[FFmpeg-trac] #1558(avformat:open): Artefacts and wrong duration when decoding a (possibly damaged) matroska file (was: Unable to decode a (possibly damaged) matroska file)

FFmpeg trac at avcodec.org
Mon Oct 21 12:09:55 CEST 2013


#1558: Artefacts and wrong duration when decoding a (possibly damaged) matroska
file
-------------------------------------+-------------------------------------
             Reporter:  cehoyos      |                    Owner:
                 Type:  defect       |                   Status:  open
             Priority:  normal       |                Component:  avformat
              Version:  git-master   |               Resolution:
             Keywords:  mkv          |               Blocked By:
  duration roundup                   |  Reproduced by developer:  1
             Blocking:               |
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
Changes (by cehoyos):

 * keywords:  mkv roundup => mkv duration roundup
 * status:  new => open
 * reproduced:  0 => 1


Comment:

 The sample plays now but shows heavy artefacts in the beginning that are
 not visible with vlc, shown duration is wrong, see ticket #3066.
 {{{
 $ ffmpeg -i matroska_crash.mkv -qscale 2 out.mkv
 ffmpeg version N-57288-g09ba986 Copyright (c) 2000-2013 the FFmpeg
 developers
   built on Oct 21 2013 12:07:28 with gcc 4.7 (SUSE Linux)
   configuration: --enable-gpl
   libavutil      52. 47.101 / 52. 47.101
   libavcodec     55. 37.102 / 55. 37.102
   libavformat    55. 19.103 / 55. 19.103
   libavdevice    55.  4.100 / 55.  4.100
   libavfilter     3. 88.102 /  3. 88.102
   libswscale      2.  5.101 /  2.  5.101
   libswresample   0. 17.104 /  0. 17.104
   libpostproc    52.  3.100 / 52.  3.100
 [matroska,webm @ 0x1e12880] Unknown entry 0x6E1F
 [matroska,webm @ 0x1e12880] Unknown entry 0x48B2
 [matroska,webm @ 0x1e12880] Read error at pos. 2376 (0x948)
 [matroska,webm @ 0x1e12880] Unknown entry 0x81
 [matroska,webm @ 0x1e12880] Read error at pos. 192 (0xc0)
 [matroska,webm @ 0x1e12880] Unknown entry 0x82
 Truncating packet of size 1304136787 to 4682756
 [matroska,webm @ 0x1e12880] Unknown entry 0x67C9
     Last message repeated 1 times
 [matroska,webm @ 0x1e12880] Unknown entry 0x82
 Truncating packet of size 1304137043 to 4682741
 [matroska,webm @ 0x1e12880] Unknown entry 0x83
     Last message repeated 4 times
 Truncating packet of size 1304137043 to 4682661
 [matroska,webm @ 0x1e12880] Unknown entry 0x83
 Truncating packet of size 491633549 to 4682646
 [matroska,webm @ 0x1e12880] Unknown entry 0x83
 Truncating packet of size 881479099 to 4682631
 [matroska,webm @ 0x1e12880] Unknown entry 0x83
 Truncating packet of size 75773773 to 4682616
 [matroska,webm @ 0x1e12880] Unknown entry 0x83
 Truncating packet of size 198743885 to 4682600
 [matroska,webm @ 0x1e12880] Unknown entry 0x83
 [matroska,webm @ 0x1e12880] Unknown entry 0x7B4C
 [matroska,webm @ 0x1e12880] Unknown entry 0x7DAC
 [matroska,webm @ 0x1e12880] Unknown entry 0xC9
 [matroska,webm @ 0x1e12880] Unknown entry 0x81
 [matroska,webm @ 0x1e12880] Unknown entry 0x90
 [matroska,webm @ 0x1e12880] Unknown entry 0xF1
 [matroska,webm @ 0x1e12880] Unknown entry 0x55B1
 Truncating packet of size 182616600 to 4128317
 [mpeg4 @ 0x1e15560] hmm, seems the headers are not complete, trying to
 guess time_increment_bits
 [mpeg4 @ 0x1e15560] my guess is 5 bits ;)
 [matroska,webm @ 0x1e12880] Estimating duration from bitrate, this may be
 inaccurate
 [matroska,webm @ 0x1e12880] Could not find codec parameters for stream 3
 (Audio: mp3, 48000 Hz, 2 channels, s16p): unspecified frame size
 Consider increasing the value for the 'analyzeduration' and 'probesize'
 options
 [matroska,webm @ 0x1e12880] Could not find codec parameters for stream 5
 (Audio: mp3, 48000 Hz, 2 channels, s16p): unspecified frame size
 Consider increasing the value for the 'analyzeduration' and 'probesize'
 options
 Guessed Channel Layout for  Input Stream #0.3 : stereo
 Guessed Channel Layout for  Input Stream #0.5 : stereo
 Input #0, matroska,webm, from 'matroska_crash.mkv':
   Metadata:
     creation_time   : 2005-07-28 20:39:44
   Duration: 00:06:30.25, start: 0.000000, bitrate: 96 kb/s
     Chapter #0.0: start 0.000000, end 15.000000
     Metadata:
       title           : Introduction
     Chapter #0.1: start 15.000000, end 30.000000
     Metadata:
       title           : Developpement
     Chapter #0.2: start 30.000000, end 45.200000
     Metadata:
       title           : Conclusion
     Stream #0:0(eng): Video: mpeg4 (Simple Profile) (DX50 / 0x30355844),
 yuv420p, 720x400 [SAR 1:1 DAR 9:5], 25 fps, 25 tbr, 1k tbn, 25 tbc
 (default)
     Stream #0:1(eng): Audio: mp3, 48000 Hz, stereo, s16p, 96 kb/s
 (default)
     Stream #0:2(eng): Video: mpeg4 (DX50 / 0x30355844), yuv420p, 720x400,
 SAR 1:1 DAR 9:5, 25 fps, 25 tbr, 1k tbn, 1k tbc (default)
     Stream #0:3(eng): Audio: mp3, 48000 Hz, stereo, s16p (default)
     Stream #0:4(eng): Video: mpeg4 (DX50 / 0x30355844), yuv420p, 720x400,
 SAR 1:1 DAR 9:5, 25 fps, 25 tbr, 1k tbn, 1k tbc (default)
     Stream #0:5(eng): Audio: mp3, 48000 Hz, stereo, s16p (default)
 Please use -q:a or -q:v, -qscale is ambiguous
 Output #0, matroska, to 'out.mkv':
   Metadata:
     encoder         : Lavf55.19.103
     Chapter #0.0: start 0.000000, end 15.000000
     Metadata:
       title           : Introduction
     Chapter #0.1: start 15.000000, end 30.000000
     Metadata:
       title           : Developpement
     Chapter #0.2: start 30.000000, end 45.200000
     Metadata:
       title           : Conclusion
     Stream #0:0(eng): Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 720x400
 [SAR 1:1 DAR 9:5], q=2-31, 200 kb/s, 1k tbn, 25 tbc (default)
     Stream #0:1(eng): Audio: ac3 ([0] [0][0] / 0x2000), 48000 Hz, stereo,
 fltp, 192 kb/s (default)
 Stream mapping:
   Stream #0:0 -> #0:0 (mpeg4 -> mpeg4)
   Stream #0:1 -> #0:1 (mp3 -> ac3)
 Press [q] to stop, [?] for help
 [mpeg4 @ 0x205fb00] warning: first frame is no keyframe
 frame=  953 fps=0.0 q=2.0 Lsize=    8082kB time=00:00:45.20
 bitrate=1464.8kbits/s
 video:7170kB audio:893kB subtitle:0 global headers:0kB muxing overhead
 0.229468%
 }}}

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1558#comment:2>
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