[FFmpeg-devel] [PATCH] avfilter/f_realtime: add option to scale speed

Moritz Barsnick barsnick at gmx.net
Thu Dec 27 03:13:10 EET 2018


On Wed, Dec 26, 2018 at 18:37:42 +0100, Nicolas George wrote:
> > I'm not sure scaling the limit by the factor is the correct idea.  It feels
> > right regarding the discontinuities, but not according to the limit option's
> > description.
> 
> I think it would be more logical to keep limit expressed as real time.
> This option is a safety net, it is not nimble enough to select time gaps
> to ignore in files that contain them.

So the limit shall be in "real" realtime? In other words, if the max
sleep time limit is 2 seconds (default), it shall stay there, even if a
speed < 1 slowdown extends all sleep times?

(The use case is, for example: Slowdown a 25 fps stream with 0.01, all
sleep times will be around 4 seconds, and therefore be skipped, which
is not quite intended. The user would need to adapt the limit
explicitly.)

> I should have used FFABS(sleep); if this hunk stays, then better make
> the change to have only one division:
> 
> 	if (FFABS(sleep) > s->limit / s->speed)

I can do so. Who decides whether the hunks stays or goes? I'm
indecisive.

> LGTM apart from these nitpicks.

Thanks,
Moritz


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