[FFmpeg-trac] #3690(avcodec:new): Field-encoded MPEG-2 samples allow to seek to a non-key frame / show artefacts

[FFmpeg]

#3690: Field-encoded MPEG-2 samples allow to seek to a non-key frame / show
artefacts
-------------------------------------+-------------------------------------
               Reporter:  cehoyos    |                  Owner:
                   Type:  defect     |                 Status:  new
               Priority:  normal     |              Component:  avcodec
                Version:  git-       |               Keywords:  mpeg2video
  master                             |  seek
             Blocked By:             |               Blocking:
Reproduced by developer:  0          |  Analyzed by developer:  0
-------------------------------------+-------------------------------------
 Some field-encoded mpeg2video samples do not skip non-keyframes when
 seeking.
 {{{
 $ ffmpeg -ss 1 -i Ondine_clip_cut.mpg -vframes 1 out.jpg
 ffmpeg version N-63598-gca2ec98 Copyright (c) 2000-2014 the FFmpeg
 developers
   built on May 30 2014 13:42:12 with gcc 4.7 (SUSE Linux)
   configuration: --enable-gpl
   libavutil      52. 87.100 / 52. 87.100
   libavcodec     55. 65.100 / 55. 65.100
   libavformat    55. 42.100 / 55. 42.100
   libavdevice    55. 13.101 / 55. 13.101
   libavfilter     4.  5.100 /  4.  5.100
   libswscale      2.  6.100 /  2.  6.100
   libswresample   0. 19.100 /  0. 19.100
   libpostproc    52.  3.100 / 52.  3.100
 Input #0, mpeg, from 'Ondine_clip_cut.mpg':
   Duration: 00:00:03.18, start: 0.278144, bitrate: 6440 kb/s
     Stream #0:0[0x1e0]: Video: mpeg2video (Main), yuv420p(tv, bt470bg),
 720x576 [SAR 16:15 DAR 4:3], max. 9000 kb/s, 25 fps, 25 tbr, 90k tbn, 50
 tbc
     Stream #0:1[0x80]: Audio: ac3, 48000 Hz, stereo, fltp, 192 kb/s
 [swscaler @ 0x27e0380] deprecated pixel format used, make sure you did set
 range correctly
 Output #0, image2, to 'out.jpg':
   Metadata:
     encoder         : Lavf55.42.100
     Stream #0:0: Video: mjpeg, yuvj420p, 720x576 [SAR 16:15 DAR 4:3],
 q=2-31, 200 kb/s, 25 fps, 90k tbn, 25 tbc
     Metadata:
       encoder         : Lavc55.65.100 mjpeg
 Stream mapping:
   Stream #0:0 -> #0:0 (mpeg2video -> mjpeg)
 Press [q] to stop, [?] for help
 frame=    1 fps=0.0 q=1.6 Lsize=N/A time=00:00:00.04 bitrate=N/A
 video:7kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB
 muxing overhead: unknown
 }}}
 out.jpg is gray.

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Ticket URL: <https://trac.ffmpeg.org/ticket/3690>
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