[FFmpeg-user] I found the bugs

[Rob Hallam]

On Wed, 19 Jun 2024 at 14:23, Mark Filipak <markfilipak.imdb at gmail.com> wrote:

> I think this may be a far ranging bug that affects '-ss' and that provokes many of the
> "non-monotonous DTS" error messages that seem to appear out of nowhere when a trivial, non-timing,
> non-timestamp change is made to a transcode or to a remux. I confess that I write "I think" rather
> than "We think" because I've not yet gotten others on ffmpeg-user to look at Ticket_11055.m2ts and
> to take this issue seriously enough to join me. Certainly, no one else on ffmpeg-user has
> communicated that they've tested (or even watched) Ticket_11055.m2ts.

I downloaded and played Ticket_11055.m2ts with vlc and mpv (which I
installed to perform this test).

Results appended below message, please let me know if you want this
posted to the bug report on trac.

Perceptually, both seem to play "properly", ie without pauses;
however, mpv does note an "invalid video timestamp".

Cheers & HTH,
Rob

---------- Results ----------

$ time mpv Ticket_11055.m2ts
 (+) Video --vid=1 (h264 1920x1080 23.976fps)
 (+) Audio --aid=1 (dts 1ch 48000Hz)
AO: [pulse] 48000Hz mono 1ch s32
VO: [gpu] 1920x1080 yuv420p
Invalid video timestamp: 4.078233 -> 3.994822
AV: 00:00:04 / 00:00:04 (99%) A-V:  0.000
Exiting... (End of file)

real    0m4.285s
user    0m1.167s
sys     0m0.167s

$ time vlc --play-and-exit Ticket_11055.m2ts
VLC media player 3.0.20 Vetinari (revision 3.0.20-0-g6f0d0ab126b)
[--- generic nonspecific vlc complaints trimmed ---]
[00007f1010c0a4f0] avcodec decoder: Using NVIDIA VDPAU Driver Shared
Library  535.179  Fri Apr 26 21:32:27 UTC 2024 for hardware decoding
[000055a606d597b0] main playlist: end of playlist, exiting

real    0m4.591s
user    0m0.294s
sys     0m0.236s

$ mpv --version
mpv v0.38.0-dirty Copyright © 2000-2024 mpv/MPlayer/mplayer2 projects
 built on May 23 2024 10:29:03
libplacebo version: v6.338.2
FFmpeg version: n6.1.1
FFmpeg library versions:
   libavutil       58.29.100
   libavcodec      60.31.102
   libavformat     60.16.100
   libswscale      7.5.100
   libavfilter     9.12.100
   libswresample   4.12.100

$ vlc --version
VLC media player 3.0.20 Vetinari (revision 3.0.20-0-g6f0d0ab126b)
VLC version 3.0.20 Vetinari (3.0.20-0-g6f0d0ab126b)
Compiled by builduser on  (May  4 2024 17:53:32)
Compiler: gcc version 13.2.1 20240417 (GCC)
This program comes with NO WARRANTY, to the extent permitted by law.
You may redistribute it under the terms of the GNU General Public Licence;
see the file named COPYING for details.
Written by the VideoLAN team; see the AUTHORS file.