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

[Ivan Kalvachev]

2006/2/8, Markus Kaiserswerth <mkaiserswerth at inetmx.de>:
> 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.

It looks like ffmpeg bug. What version are you using? Have you tried
lastest one, or with older (e.g. 1,2,3 months ago)?

Are you using shared version of libavcodec?
What is your distro, system, processor etc...