[MPlayer-dev-eng] new results & bugs report

[Michael Niedermayer]

Hi

On Tuesday 15 June 2004 11:54, Loren Merritt wrote:
> On Tue, 15 Jun 2004, Romain Dolbeau wrote:
> > D Richard Felker III wrote:
> > > Umm, macroblocks are 16x16. Need I say more??
> >
> > Yes (I suppose I'm a bit dumb, and I know I don't know much
> > about MPEG-4). I don't understand why it actually works if
> > the unit of work is 16x16. Or are macroblocks only an optional
> > part of the encoding ? In that case, I assume the bottom lines
> > would waste bits by not using them (no enough lines), or
> > alternatively the quality would be worse.
>
> MPEG-4 always works in 16x16 macroblocks (and 8x8 lumablocks). If your
> video is not a multiple of the block size, then the partial blocks will
> be padded with black.
not necessarily, its up to the encoder what to fill into these non-visible 
parts, so normally the area is filled by duplicating the outermost pixels or 
to mirror them

btw, the wasted space, needs memory, filesize and cpu to encode/decode, for 
example 514x386 = 198404 pixels and the wasted space is 12796 pixels which is 
~6.4%

[...]
-- 
Michael
level[i]= get_vlc(); i+=get_vlc();		(violates patent EP0266049)
median(mv[y-1][x], mv[y][x-1], mv[y+1][x+1]);	(violates patent #5,905,535)
buf[i]= qp - buf[i-1];				(violates patent #?)
for more examples, see http://mplayerhq.hu/~michael/patent.html
stop it, see http://petition.eurolinux.org & http://petition.ffii.org/eubsa/en