[MEncoder-users] new doom9 codec comparission

Michael Niedermayer michaelni at gmx.at
Tue Dec 6 12:20:17 CET 2005


On Mon, Dec 05, 2005 at 11:29:56PM -0800, Corey Hickey wrote:
> I've been quiet for the past couple days because it took a while to get
> some conclusive results in the time I had. My work is paying off,
> however, and I should be able to submit a set of very refined mpeg-4
> lavcopts for your review some time tomorrow. I have a few tests left to
> run overnight.
> Some interesting notes:
> Adding b-frames does indeed increase PSNR on this movie.
> vmax_b_frames=0:   PSNR: Y:41.31, Cb:44.26, Cr:44.73, All:42.13
> vmax_b_frames=1:   PSNR: Y:41.72, Cb:44.83, Cr:45.42, All:42.58
> vmax_b_frames=2:   PSNR: Y:41.78, Cb:44.93, Cr:45.57, All:42.66
> vmax_b_frames=3:   PSNR: Y:41.71, Cb:44.99, Cr:45.65, All:42.61
> I stuck with vmax_b_frames=2. Using vb_strategy=1 on the first pass
> always decreased final PSNR slightly; quality was slightly lower as well.
> Thanks go to Jan Knutar for pointing out a potential pitfall -- there
> was indeed some flickering produced by using spp=2 to play the videos
> with b-frames. When I looked closely, the flickering was still there
> without spp, just less visible. Removing the quantizer difference

retry, spp shouldnt add any flicker anymore


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