[FFmpeg-trac] #9269(undetermined:new): ffmpeg produces broken files when cutting mp4s

[FFmpeg]

#9269: ffmpeg produces broken files when cutting mp4s
-------------------------------------+-------------------------------------
             Reporter:  Artem S.     |                     Type:  defect
  Tashkinov                          |
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:  git-
  undetermined                       |  master
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug: when fast seeking along with specifying the length,
 ffmpeg produces files with broken PTS timestamps.

 How to reproduce:
 {{{
 /tmp/ffmpeg/ffmpeg -ss 00:01:00 -i "source.mp4" -t 10 -c copy
 /tmp/100-10.mp4
 ffmpeg version N-102619-gebedd26eef Copyright (c) 2000-2021 the FFmpeg
 developers
   built with gcc 10 (GCC)
   configuration: --disable-static --enable-nonfree --enable-avfilter
 --disable-shared --enable-static --enable-gpl --enable-postproc --enable-
 pthreads --enable-libspeex --enable-libmp3lame --enable-libx264 --enable-
 libxvid --enable-libopus --enable-libopenjpeg --disable-debug --disable-
 doc --enable-libpulse --extra-cflags='-mtune=generic' --enable-version3
 --enable-libvorbis --enable-libfdk-aac --enable-gnutls --enable-
 libfreetype --enable-libx265 --enable-libdav1d --libdir=/usr/local/lib64
 --enable-lto --enable-pic --prefix=/tmp/ffmpeg
   libavutil      57.  0.100 / 57.  0.100
   libavcodec     59.  1.100 / 59.  1.100
   libavformat    59.  2.101 / 59.  2.101
   libavdevice    59.  0.100 / 59.  0.100
   libavfilter     8.  0.101 /  8.  0.101
   libswscale      6.  0.100 /  6.  0.100
   libswresample   4.  0.100 /  4.  0.100
   libpostproc    56.  0.100 / 56.  0.100
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'source.mp4':
   Metadata:
     major_brand     : mp42
     minor_version   : 0
     compatible_brands: isommp42
   Duration: 00:02:30.14, start: 0.000000, bitrate: 17106 kb/s
   Stream #0:0(eng): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p,
 1920x1080, 16995 kb/s, SAR 1:1 DAR 16:9, 29.85 fps, 29.85 tbr, 90k tbn
 (default)
     Metadata:
       handler_name    : VideoHandle
       vendor_id       : [0][0][0][0]
   Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, mono,
 fltp, 96 kb/s (default)
     Metadata:
       handler_name    : SoundHandle
       vendor_id       : [0][0][0][0]
 Output #0, mp4, to '/tmp/100-10.mp4':
   Metadata:
     major_brand     : mp42
     minor_version   : 0
     compatible_brands: isommp42
     encoder         : Lavf59.2.101
   Stream #0:0(eng): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p,
 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 16995 kb/s, 29.85 fps, 29.85 tbr,
 90k tbn (default)
     Metadata:
       handler_name    : VideoHandle
       vendor_id       : [0][0][0][0]
   Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, mono,
 fltp, 96 kb/s (default)
     Metadata:
       handler_name    : SoundHandle
       vendor_id       : [0][0][0][0]
 Stream mapping:
   Stream #0:0 -> #0:0 (copy)
   Stream #0:1 -> #0:1 (copy)
 Press [q] to stop, [?] for help
 frame=  323 fps=0.0 q=-1.0 Lsize=   22611kB time=00:00:10.01
 bitrate=18499.6kbits/s speed=1.12e+03x
 video:22473kB audio:127kB subtitle:0kB other streams:0kB global
 headers:0kB muxing overhead: 0.046347%
 }}}


 Tested with ffmpeg-4.4 and the current ffmpeg snapshot.

 Also discussed here: https://github.com/mpv-player/mpv/issues/8876

 The resulting files produced by ffmpeg:

 4.4 https://drive.google.com/file/d/1hdK51zO0ANLjIX9bC_OVd-
 jBv7_ReLbH/view?usp=sharing

 GIT: https://drive.google.com/file/d/1AWnpx3xgf7g-
 oiYLE3HGzlRouXe6Ea4T/view?usp=sharing

 Using slow seeking (-i timestamp after the source file) fixes the issue.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/9269>
FFmpeg <https://ffmpeg.org>
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