[FFmpeg-trac] #493(undetermined:open): flash h.264 recorded files on FMS - bad duration and timing after ffmpeg conversion

[FFmpeg]

#493: flash h.264 recorded files on FMS - bad duration and timing after ffmpeg
conversion
-------------------------------------+-------------------------------------
             Reporter:  kruzel       |                    Owner:  michael
                 Type:  enhancement  |                   Status:  open
             Priority:  minor        |                Component:
              Version:  git-master   |  undetermined
             Keywords:  mp4 edit     |               Resolution:
  lists                              |               Blocked By:
             Blocking:               |  Reproduced by developer:  1
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
Changes (by cehoyos):

 * status:  new => open
 * reproduced:  0 => 1
 * component:  FFmpeg => undetermined
 * priority:  important => minor
 * keywords:  h.264, conversion, duration, time => mp4 edit lists
 * type:  defect => enhancement


Comment:

 Do you think this is a regression?

 Afaict, FFmpeg correctly warns that there will be problems (A/V desync)
 decoding this sample.

 Sample is ~6.8 seconds, has 124 frames, only two are encoded (three for
 out.mov), audio is complete:
 {{{
 $ ffmpeg -i host.mp4 -qscale 2 out.avi
 ffmpeg version N-32748-g358d837, Copyright (c) 2000-2011 the FFmpeg
 developers
   built on Sep 21 2011 11:43:56 with gcc 4.5.3
   configuration: --cc=/usr/local/gcc-4.5.3/bin/gcc --enable-libspeex
   libavutil    51. 16. 1 / 51. 16. 1
   libavcodec   53. 16. 0 / 53. 16. 0
   libavformat  53. 12. 0 / 53. 12. 0
   libavdevice  53.  4. 0 / 53.  4. 0
   libavfilter   2. 43. 2 /  2. 43. 2
   libswscale    2.  1. 0 /  2.  1. 0
 [mov,mp4,m4a,3gp,3g2,mj2 @ 0x12b6780] multiple edit list entries, a/v
 desync might occur, patch welcome
     Last message repeated 2 times
 [libspeex @ 0x12be7a0] Missing Speex header, assuming defaults.

 Seems stream 0 codec frame rate differs from container frame rate: 48.00
 (48/1) -> 0.08 (1/12)
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'host.mp4':
   Metadata:
     major_brand     : f4v
     minor_version   : 0
     compatible_brands: isommp42m4v
     creation_time   : 2017-01-08 23:56:30
   Duration: 00:00:20.40, start: 0.000000, bitrate: 172 kb/s
     Stream #0.0(eng): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p,
 320x240 [SAR 1:1 DAR 4:3], 0.08 tbr, 1k tbn, 48 tbc
     Metadata:
       creation_time   : 2017-01-08 23:56:30
     Stream #0.1(eng): Audio: speex (spex / 0x78657073), 16000 Hz, 1
 channels, s16
     Metadata:
       creation_time   : 2017-01-08 23:56:30
     Stream #0.2(eng): Data: none (amf0 / 0x30666D61)
     Metadata:
       creation_time   : 2017-01-08 23:56:30
 [buffer @ 0x12d5c00] w:320 h:240 pixfmt:yuv420p tb:1/1000000 sar:1/1
 sws_param:
 Incompatible sample format 's16' for codec 'ac3', auto-selecting format
 'flt'
 [ac3 @ 0x12d89e0] channel_layout not specified
 [ac3 @ 0x12d89e0] No channel layout specified. The encoder will guess the
 layout, but it might be incorrect.
 [libspeex @ 0x12be7a0] Missing Speex header, assuming defaults.
 Output #0, avi, to 'out.avi':
   Metadata:
     major_brand     : f4v
     minor_version   : 0
     compatible_brands: isommp42m4v
     creation_time   : 2017-01-08 23:56:30
     ISFT            : Lavf53.12.0
     Stream #0.0(eng): Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 320x240
 [SAR 1:1 DAR 4:3], q=2-31, 200 kb/s, 0.08 tbn, 0.08 tbc
     Metadata:
       creation_time   : 2017-01-08 23:56:30
     Stream #0.1(eng): Audio: ac3 ([0] [0][0] / 0x2000), 16000 Hz, mono,
 flt, 128 kb/s
     Metadata:
       creation_time   : 2017-01-08 23:56:30
 Stream mapping:
   Stream #0.0 -> #0.0 (h264 -> mpeg4)
   Stream #0.1 -> #0.1 (libspeex -> ac3)
 Press [q] to stop, [?] for help
 frame=    2 fps=  0 q=2.0 Lsize=     134kB time=00:00:06.91 bitrate=
 158.5kbits/s dup=0 drop=122
 video:14kB audio:108kB global headers:0kB muxing overhead 9.390350%
 }}}

-- 
Ticket URL: <https://avcodec.org/trac/ffmpeg/ticket/493#comment:1>
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