[FFmpeg-devel] [FFmpeg-devel, RFC] lavfi: add opencl tonemap filter.

[Moritz Barsnick]

On Fri, May 11, 2018 at 10:10:42 +0200, Niklas Haas wrote:
> Thinking about this logic again, I came to realize that a different
> strategy might be to check instead for a minimum threshold brightness
> difference in a critical number of different areas of the screen. This
> way, a very bright light source appearing or becoming occluded in one
> local part of the frame will not trigger a scene change, while a sudden
> change in brightness of a large part of the frame will.

Yes, when I read your previous email, that was my thought regarding
scene change detection as well. There are others already in ffmpeg, (or
perhaps I was looking at the one in the tool "motion"?), I believe.
They ideally don't just check for overall brightness change, but over
several squares / blocks and take that into consideration.

Reasoning:

- There's a quite high chance that a scene change with a totally
  different picture layout has approx. the same average brightness as
  the scene before.

- A strong change in only one or two of e.g. 100 rectangles should not
  indicate a scene change (while it might indicate motion, different
  concept there).

Moritz