[FFmpeg-trac] #6421(undetermined:new): PTS incorrectly fixed up to be negative

[FFmpeg]

#6421: PTS incorrectly fixed up to be negative
-------------------------------------+-------------------------------------
             Reporter:  sandersd     |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  important    |                Component:
              Version:  git-master   |  undetermined
             Keywords:  mov h264     |               Resolution:
  edts regression                    |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------

Comment (by sandersd):

 > I only found 7001A.mp4 and nonFormattedMetaData.mp4, where can I get
 MVI_5623.mp4?


 MVI_5623.mp4 is linked from the initial user report of the first bug,
 https://bugs.chromium.org/p/chromium/issues/detail?id=723537.


 > Why do you think this is an issue?


 The demuxer still reports a track start time of zero. This breaks playback
 in Chrome, but more importantly it prevents correct A/V sync.


 > I cannot reproduce negative timestamps with nonFormattedMetaData.mp4


 I see that the second PTS is negative with a tip-of-tree build from today:

 {{{
 $ ~/opt/ffmpeg-git/ffprobe -show_packets -select_streams video -i
 nonFormattedMetaData.mp4 | head -n 30
 ffprobe version N-86265-gb946bd8ef2 Copyright (c) 2007-2017 the FFmpeg
 developers
   built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04.3)
   configuration: --enable-gpl --enable-libvpx --enable-libx264
   libavutil      55. 63.100 / 55. 63.100
   libavcodec     57. 96.101 / 57. 96.101
   libavformat    57. 72.101 / 57. 72.101
   libavdevice    57.  7.100 / 57.  7.100
   libavfilter     6. 90.100 /  6. 90.100
   libswscale      4.  7.101 /  4.  7.101
   libswresample   2.  8.100 /  2.  8.100
   libpostproc    54.  6.100 / 54.  6.100
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'nonFormattedMetaData.mp4':
   Metadata:
     major_brand     : mp42
     minor_version   : 1
     compatible_brands: mp42avc1CAEP
     creation_time   : 2017-05-25T11:52:00.000000Z
   Duration: 00:00:32.03, start: 0.000000, bitrate: 4024 kb/s
     Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv,
 bt709), 1280x720, 3852 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 60k tbc
 (default)
     Metadata:
       creation_time   : 2017-05-25T11:52:00.000000Z
     Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz,
 stereo, fltp, 127 kb/s (default)
     Metadata:
       creation_time   : 2017-05-25T11:52:00.000000Z
 [PACKET]
 codec_type=video
 stream_index=0
 pts=0
 pts_time=0.000000
 dts=-3003
 dts_time=-0.100100
 duration=1001
 duration_time=0.033367
 convergence_duration=N/A
 convergence_duration_time=N/A
 size=109271
 pos=171912
 flags=K_
 [/PACKET]
 [PACKET]
 codec_type=video
 stream_index=0
 pts=-2002
 pts_time=-0.066733
 dts=-2002
 dts_time=-0.066733
 duration=1001
 duration_time=0.033367
 convergence_duration=N/A
 convergence_duration_time=N/A
 size=12534
 pos=281183
 flags=__
 [/PACKET]
 }}}

--
Ticket URL: <https://trac.ffmpeg.org/ticket/6421#comment:2>
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