[FFmpeg-user] Why are these different?

[Paul B Mahol]

On Thu, Feb 8, 2024 at 9:34 PM Mark Filipak <markfilipak.imdb at gmail.com>
wrote:

> On 08/02/2024 15.16, Paul B Mahol wrote:
> >
> > I think, that one of variant use seeking (in container via demuxer) and
> > other one use frame seeking by decoding everything from start using trim
> > filters.
>
> Nope. Neither is decoding -- too fast -- as though decoding would/should
> make a difference.
>
> Here's '-ss' before '-i' (definitely using demuxer):
> size=  247808kB time=00:01:02.90 bitrate=32273.5kbits/s speed=2.23x
>
> Here's '-i' before '-ss':
> size=  592384kB time=00:02:33.87 bitrate=31537.1kbits/s speed=4.35x
>
> The '-i' before '-ss' case is actually faster.
>

Because one of them actually seek to that position by some heuristic (so it
might not be perfect as seeking depends on container specifications and
bugs in implementation).
And another one decodes everything from start but ignores data until
requested position (dunno if that one is perfect by current state of code).


> --Mark.
>
>
> _______________________________________________
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-user
>
> To unsubscribe, visit link above, or email
> ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".
>