[MPlayer-users] Deblocking B-frames

[Loren Merritt]

On Sat, 8 May 2004, Ville Saari wrote:

> When pp=hb/vb is used for mpeg[124] with B-frames, the result is a
> flicker that is more annoying than the blocking was. Apparently it
> adjusts the filtering strength based on quantizer only, which causes
> the B-frames to be filtered harder.
>
> This is obviously wrong. Although the B-frames have higher quantizers,
> their artifacts are not stronger or if they are, then the video is badly
> encoded. If I encode lavc mpeg4 with constant quantizer 2 for [IP]-frames
> and 4 for B-frames, then the result is very well balanced between different
> frame types (subjectively and by psnr).
>
> I believe that the proper behaviour for pp would be either to apply
> a vb_qfactor/vb_qoffset-like correction to B-frame quantizers or
> just to ignore the quantizer for B-frames and use the one from the
> last non-B-frame instead.

try pp=h1/v1

--Loren Merritt