[FFmpeg-trac] #8895(avformat:new): Advanced Edit List support causes decode errors

[FFmpeg]

#8895: Advanced Edit List support causes decode errors
-------------------------------------+-------------------------------------
               Reporter:  dbuitenh   |                  Owner:
                   Type:  defect     |                 Status:  new
               Priority:  normal     |              Component:  avformat
                Version:             |               Keywords:  mov
  unspecified                        |  editlist
             Blocked By:             |               Blocking:
Reproduced by developer:  0          |  Analyzed by developer:  0
-------------------------------------+-------------------------------------
 Summary of the bug:

 The "advanced edit list" code in libavformat's MOV/MP4 demuxer causes
 decode errors on some files. I think this is related to the fact that
 these files are frames stored out of order with negative entries in the
 CTTS atom, and the edit list reodering/frame dropping/GOP code doesn't
 handle this properly, since it was written with only MP4 in mind, which
 only has unsigned value in the CTTS box (MOV can have signed values). As a
 result, some edit list entries cause decode errors and artifacting (see
 below). Disabling the advanced edit list code (aka not hanling it at all)
 with -advanced_editlist 0 or -ignored_editlist 1 prevents these decode
 errors.

 Also of note is that this file as a CSLG atom, which FFmpeg seems to not
 parse at all, which could also be related.

 How to reproduce:
 {{{
 % ffmpeg -i test2.mov -f null -
 ffmpeg version N-99165-gfda5363c80 Copyright (c) 2000-2020 the FFmpeg
 developers
   built with clang version 9.0.1-14
   configuration: --cc=clang
   libavutil      56. 59.100 / 56. 59.100
   libavcodec     58.106.100 / 58.106.100
   libavformat    58. 56.100 / 58. 56.100
   libavdevice    58. 11.102 / 58. 11.102
   libavfilter     7. 87.100 /  7. 87.100
   libswscale      5.  8.100 /  5.  8.100
   libswresample   3.  8.100 /  3.  8.100
 MUH SHIFT = 1
     Last message repeated 5 times
 MUH SHIFT = 0
     Last message repeated 1 times
 Guessed Channel Layout for Input Stream #0.1 : stereo
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'test2.mov':
   Metadata:
     major_brand     : qt
     minor_version   : 537199360
     compatible_brands: qt
     creation_time   : 2020-08-13T20:58:58.000000Z
     com.apple.finalcutstudio.media.uuid: 41E16D85-BEBA-4ADE-
 8AB4-A0E359562D54
   Duration: 00:59:36.72, start: 0.000000, bitrate: 5 kb/s
     Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv,
 bt709, progressive), 1920x1080, 1003 kb/s, 25 fps, 25 tbr, 25 tbn, 50 tbc
 (default)
     Metadata:
       creation_time   : 2020-08-13T20:58:58.000000Z
       handler_name    : Apple Video Media Handler
       encoder         : AVC Coding
       timecode        : 00:00:00:00
     Stream #0:1(eng): Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz,
 stereo, s16, 1536 kb/s (default)
     Metadata:
       creation_time   : 2020-08-13T20:58:58.000000Z
       handler_name    : Apple Sound Media Handler
     Stream #0:2(eng): Data: none (tmcd / 0x64636D74) (default)
     Metadata:
       creation_time   : 2020-08-13T20:59:27.000000Z
       handler_name    : Time Code Media Handler
       timecode        : 00:00:00:00
 Stream mapping:
   Stream #0:0 -> #0:0 (h264 (native) -> wrapped_avframe (native))
   Stream #0:1 -> #0:1 (pcm_s16le (native) -> pcm_s16le (native))
 Press [q] to stop, [?] for help
 Output #0, null, to 'pipe:':
   Metadata:
     major_brand     : qt
     minor_version   : 537199360
     compatible_brands: qt
     com.apple.finalcutstudio.media.uuid: 41E16D85-BEBA-4ADE-
 8AB4-A0E359562D54
     encoder         : Lavf58.56.100
     Stream #0:0(eng): Video: wrapped_avframe, yuv420p, 1920x1080, q=2-31,
 200 kb/s, 25 fps, 25 tbn, 25 tbc (default)
     Metadata:
       creation_time   : 2020-08-13T20:58:58.000000Z
       handler_name    : Apple Video Media Handler
       timecode        : 00:00:00:00
       encoder         : Lavc58.106.100 wrapped_avframe
     Stream #0:1(eng): Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
 (default)
     Metadata:
       creation_time   : 2020-08-13T20:58:58.000000Z
       handler_name    : Apple Sound Media Handler
       encoder         : Lavc58.106.100 pcm_s16le
 [h264 @ 0x2d7ad80] number of reference frames (0+2) exceeds max (1;
 probably corrupt input), discarding one
 [h264 @ 0x2d7ad80] co located POCs unavailable
 [h264 @ 0x2d7ad80] reference count overflow
 [h264 @ 0x2d7ad80] decode_slice_header error

 [errors continue for a long time from here]
 }}}

 I have attached a trimmed 2.5mb version of one of these files that should
 be sufficient for testing and reproducing, but I also have the creator's
 permission to share the whole ~1gb file if necessary or prudent.

--
Ticket URL: <https://trac.ffmpeg.org/ticket/8895>
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