[FFmpeg-trac] #1438(avformat:open): Seeking in vob file with timestamp wrap fails (was: problems with using -ss option when transcoding from *.vob to *.avi)

[FFmpeg]

#1438: Seeking in vob file with timestamp wrap fails
--------------------------------------+------------------------------------
             Reporter:  superandrzej  |                    Owner:
                 Type:  defect        |                   Status:  open
             Priority:  normal        |                Component:  avformat
              Version:  git-master    |               Resolution:
             Keywords:  mpegps seek   |               Blocked By:
             Blocking:                |  Reproduced by developer:  1
Analyzed by developer:  0             |
--------------------------------------+------------------------------------
Changes (by cehoyos):

 * status:  new => open
 * reproduced:  0 => 1
 * component:  undetermined => avformat
 * version:  unspecified => git-master
 * keywords:   => mpegps seek


Comment:

 Sample uploaded to http://samples.ffmpeg.org/ffmpeg-
 bugs/trac/ticket1438/timestamp_wrap.vob
 The sample is approximately 4:21 and contains 4 timestamp wraps. The
 segments are about 63, 54, 57, 66 and 21 seconds long. mplayer -demuxer
 mpegps seeks fine, mplayer -demuxer lavf and ffplay seek badly.
 ffmpeg -ss 16 (and below) works approximately correct, ffmpeg -ss 17 jumps
 to a position 4,5 seconds before the end, -ss 22 fails accordingly.
 If only the first 52MB (62 seconds) of the sample are used, seeking works
 fine, fails with 53 MB and more.
 {{{
 $ ffmpeg -ss 22 -i timestamp_wrap.vob out.png
 ffmpeg version N-42547-g7543fd8 Copyright (c) 2000-2012 the FFmpeg
 developers
   built on Jul 16 2012 07:44:51 with gcc 4.3.2
   configuration: --cc=/usr/local/gcc-4.3.2/bin/gcc --enable-gpl --enable-
 libopenjpeg --enable-libvorbis --enable-libspeex --enable-libmp3lame
 --enable-libtheora --extra-ldflags=-lm --enable-libvpx --enable-libxavs
 --enable-x11grab
   libavutil      51. 65.100 / 51. 65.100
   libavcodec     54. 40.100 / 54. 40.100
   libavformat    54. 16.104 / 54. 16.104
   libavdevice    54.  1.100 / 54.  1.100
   libavfilter     3.  2.100 /  3.  2.100
   libswscale      2.  1.100 /  2.  1.100
   libswresample   0. 15.100 /  0. 15.100
   libpostproc    52.  0.100 / 52.  0.100
 [mpeg @ 0x904d3c0] max_analyze_duration 5000000 reached at 5000000
 Input #0, mpeg, from 'timestamp_wrap.vob':
   Duration: 00:00:21.18, start: 0.287267, bitrate: 77341 kb/s
     Stream #0:0[0x1e0]: Video: mpeg2video (Main), yuv420p, 720x576 [SAR
 64:45 DAR 16:9], 9800 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
     Stream #0:1[0x20]: Subtitle: dvd_subtitle
     Stream #0:2[0x21]: Subtitle: dvd_subtitle
     Stream #0:3[0x22]: Subtitle: dvd_subtitle
     Stream #0:4[0x23]: Subtitle: dvd_subtitle
     Stream #0:5[0x24]: Subtitle: dvd_subtitle
     Stream #0:6[0x25]: Subtitle: dvd_subtitle
     Stream #0:7[0x26]: Subtitle: dvd_subtitle
     Stream #0:8[0x27]: Subtitle: dvd_subtitle
     Stream #0:9[0x80]: Audio: ac3, 48000 Hz, 5.1(side), s16, 448 kb/s
     Stream #0:10[0x81]: Audio: ac3, 48000 Hz, 5.1(side), s16, 384 kb/s
     Stream #0:11[0x82]: Audio: ac3, 48000 Hz, 5.1(side), s16, 384 kb/s
     Stream #0:12[0x83]: Audio: ac3, 48000 Hz, 5.1(side), s16, 384 kb/s
     Stream #0:13[0x84]: Audio: ac3, 48000 Hz, stereo, s16, 192 kb/s
     Stream #0:14[0x28]: Subtitle: dvd_subtitle
     Stream #0:15[0x29]: Subtitle: dvd_subtitle
     Stream #0:16[0x2a]: Subtitle: dvd_subtitle
 Output #0, image2, to 'out.png':
   Metadata:
     encoder         : Lavf54.16.104
     Stream #0:0: Video: png, rgb24, 720x576 [SAR 64:45 DAR 16:9], q=2-31,
 200 kb/s, 90k tbn, 25 tbc
 Stream mapping:
   Stream #0:0 -> #0:0 (mpeg2video -> png)
 Press [q] to stop, [?] for help
 [mpeg2video @ 0x9053780] ac-tex damaged at 28 13
 [mpeg2video @ 0x9053780] Warning MVs not available
 [mpeg2video @ 0x9053780] concealing 1035 DC, 1035 AC, 1035 MV errors
 frame=    0 fps=0.0 q=0.0 Lsize=       0kB time=00:00:00.00 bitrate=
 0.0kbits/s dup=0 drop=6
 video:0kB audio:0kB subtitle:0 global headers:0kB muxing overhead nan%
 Output file is empty, nothing was encoded (check -ss / -t / -frames
 parameters if used)
 }}}

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1438#comment:8>
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