[FFmpeg-user] Filter for smoothening gradual luminance changes?

[Moritz Barsnick]

On Tue, Apr 18, 2017 at 10:45:24 +0300, Markku Tavasti wrote:
> One option is to write all frames as pictures to disk, and then run 
> timelapse-deflicker.pl for them, and make video from those pictures. 
> However, that will take much time and disk space.

Only after looking at that script[*] (and the lovely videos of course) do
I understand your intent: The brightness shall follow a rolling average
of sorts, i.e. be more or less monotonic (wrong term, I know).

I'm pretty sure that ffmpeg can't do that, as I know of no filter which
will create such an average and apply it. But a filter could be
written... I don't know if it would be a candidate for upstream though.

(I'd be willing to try, but my filter writing learning skills are stuck
at a different attempt. ;-))

[*] https://github.com/rambo/timelapse/blob/master/timelapse-deflicker.pl