[FFmpeg-user] I found the bugs

[Rob Hallam]

On Wed, 19 Jun 2024 at 16:17, Mark Filipak <markfilipak.imdb at gmail.com> wrote:
> MPV is more powerful and I think you'll like it. When it loads, quickly press the [L] key
> (unshifted) to loop,

As an aside, I couldn't get mpv to loop by pressing 'L', though it
reported A-B loop; instead I created an mpv.conf file with contents

loop-file=inf

>  then press [Shift][O] to show running times. Note that running time pauses at
> 0:00.825, then 0:00.950, then resumes around 0:02.952. MPV gets timestamps from FFmpeg [note1].

I can confirm I see a pause at "23%", though mpv reports it as
00:00:00 and then a seeming jump or fast increment through
percentages. I would probably have to record the screen or something
to see exactly what happened, unless there's a way to get mpv to
produce a log.

> mpv Ticket_11055.m2ts --no-correct-pts --fps=24000/1001
> produces different behavior that implies audio timestamps are also a problem.

Yes, that produces different but odd behaviour where the video
apparently 'freezes' while audio and file progress (%) continues.

> If this bug is important to you, Rob, it deserves more thought, investigation, supporting
> documentation -- and more ideas! I hope this issue will get more participation, especially from Paul.

You have done a rather interesting deep dive into the timestamps, Bs
and Ps, etc; I am happy to reproduce things for confirmation but I'm
just a monkey that uses ffmpeg for chopping things up and (less often)
putting them together- so while I've had an obvious interest this goes
beyond my expertise! Alas I have a few full plates I have to keep
spinning (to mix metaphors) otherwise I would be tempted to join you
in the bathysphere.

Cheers,
Rob