[MPlayer-users] Postprocessing flickers when video has B-frames

[James Bostick Crowson]

I have been experimenting with different lavc options including
b-frames, and I have noticed a peculiar flickering effect when
deblocking (pp=hb/vb or pp=h1/v1) is enabled on a video with b-frames. 
The cause is, I suspect, that videos with b-frames have per-frame
quantizers of 2,4,2,4,2,4... or something similar, so a stronger
deblocking filter is applied to the b-frames than the p-frames.  This
would explain the effect I see of details popping in and out every other
frame.  In all cases the flicker goes away when deblocking is disabled. 
Perhaps a simple fix for this would be to make the deblockers use the
quantizer from the last p-frame when processing b-frames, instead of the
b-frame quantizer itself?