Created attachment 23236 [details] [review]
patch to add videogamma element to videofilters

I modified the patch to fit in with recent changes I made to
make_filter, and applied it.  Thanks for sending it.

I tested it out, and I'm a bit worried that it doesn't work very well
in YUV space.  That's not surprising, since gamma correction is
typically done in RGB space, since monitors are non-linear in RGB space.

I'm leaving this bug open, but retitiling it to reflect that it would
be better to have an RGB gamma plugin.

You're right, gamma correction in rgb space looks quite a bit better,
but since it needs several colorspace conversions to be actually
useful it becomes too slow on my system to use it. I'll attach a first
draft of a RGB gamma correction filter, currently limited to one rgb
format (defined in an ugly way since i didn't find the correct way to
do it yet). If you add this rgb gamma filter, please also leave the
YUV one in, as people with less powerful systems may find it useful (i
certainly do).

Created attachment 23264 [details]
rgb gamma correction filter

This should be folded into the existing gamma element.  I don't think
it's a problem that the ARG_GAMMA_RGB_R property doesn't make sense
for YUV.

Created attachment 23482 [details] [review]
patch to add rgb gamma correction to the gamma videofilter

With that patch the gamma filter works with both YUV and RGB, the
redgamma, greengamma and bluegamma values are only used for the RGB
version though.

ping

I currently don't have time to work on this, the patch still applies
and adds rgb gamma correction to the gamma plugin. The seperate values
for red, green and blue gamma are only used by the rgb version, and if
overall gamma is set that overrides seperate values.

Applied, thanks.