[MPlayer-users] Brightness decreases on every video frame in MPEG-2 encodes

[Markus Kaiserswerth]

Hi,

I tried converting several Xvid AVI files to MPEG-2 in the last few  
days using mencoder. The resulting MPEG-2 files play nicely, however  
the picture brightness decreases on every frame until the next  
keyframe is reached, eventually jumping back to the brightness of the  
previous keyframe. This results in a flickering effekt when watching  
the movie (dark - bright - dark - bright etc. about every half  
second) I am using a keyframe interval of 15 frames, which (I  
believe) is the PAL DVD standard.

When I set the keyframe interval to 1 (so that every frame is a  
keyframe), the effect disappears. However, this will dramatically  
increase the final file size and my computer has serious trouble  
playing those files.

Do you have any idea on how this problem could be solved? What is  
causing it?

Cheers,
Markus

P. S.: I get the same effect using ffmpeg and transcode. However, it  
seems like the problem is not present in mpeg2enc.