[FFmpeg-devel] ZMBV Improved Motion Estimation

Reimar Döffinger Reimar.Doeffinger
Fri May 9 14:07:59 CEST 2008

On Fri, May 09, 2008 at 01:28:30PM +0200, Michael Niedermayer wrote:
> On Fri, May 09, 2008 at 11:35:03AM +0200, Reimar D?ffinger wrote:
> > On Fri, May 09, 2008 at 01:04:50AM +0200, Michael Niedermayer wrote:
> > > > No I don't, actually. I'm glad you came up with a better method. Can you
> > > > explain how and why it works in 50 words or less? I'm curious.
> > > 
> > > 0th order entropy approximation
> > 
> > It might be worth noting that it is only quite correct for 16x16 blocks
> Fixed for smaller ones.

Not for those on the border if the resolution is not divisible by the
block size, which is what I was referring to. Though I think it is now
a bit better to understand.

> > and might fail completely for blocks larger than that - just because
> smaller blocks seem better on average for the videos i have

Doesn't surprise me that much, 16x16 seems rather big esp. for generally
low-resolution videos. Though ZMBV may be more designed for videos with
large same-colour areas like a commandline, file manager or such.
Can the block size easily be changed for ZMBV or would that break with all
existing decoders?

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