[FFmpeg-user] Towards better trims & concatenations

[Rob Hallam]

On Mon, 8 Jan 2024 at 12:07, Mark Filipak <markfilipak.imdb at gmail.com> wrote:

> For example, if 'v' (video) and 'a' (audio) packets go from
> v-a-a-a-a-v-a-a-a-a-v... to
> a-a-a-a-a-a-a-a-v-v-v..., then somethings wrong, eh? That's the kind of difference I'm seeing
> between the two versions of 01.mp4.

Forgive me for jumping in in the middle here, but is that strictly
true? Honest question, perhaps the spec says that they should be
identical.

In much the same way a*b*c is equivalent to b*a*c, does the order of
packets necessarily matter if the output is perceptually the same?

If the output is not perceptually the same, or there are timing issues
/ desync / other problems as a result then I can see that being a
potentially important bug.

Cheers,
Rob

PS I've been following along as I am also interested in cutting and
re-joining- my first query to this ML was about whether there's a way
to chop off the starts and ends of some clips, add transitions and
re-encode those short overlapping bits, and then join them back on to
their parent clips to avoid having to re-encode the whole lot