[Cin] Adding 'brightness/contrast' effect on track while playing can freeze Cin-GG?

[Andrea paz]

>I'll recompile with std. CFLAGS and retest.
When I tried to compile with -Ofast I had problems with keyframes in
Autos. With -O2 I had no more keyframes problems. I think
optimizations lead to instability. However the file used is the one
you can download from a previous message with attachment (cars.mp4). I
used RGBA-8bit and X11-OpenGL.