[XviD-devel] GME and Block ME

[skal]

	Hi Michael, all

On Sat, 2003-04-19 at 12:21, Michael Niedermayer wrote:
> Hi
> 
> On Saturday 19 April 2003 08:56, Marco Al wrote:
> > From: "Michael Niedermayer" <michaelni at gmx.at>
> >
> > > yes sounds better, ill change ffmpeg/mencoder docs to that :)
> >
> > Hey, since you are reading this a question :) Does your code do an optimal
> > search or an M-best search?
> optimal, except that only 0, level, level-1 are checked, IIRC additionaly 
> checking level-2 had only a few byte lower filesize at constant quant, the 
> level-2 code is there and outcommented if u want to try

	just to split a hair four ways :

	actually, there's another "sub-optimality": you use the 
	"last_non_zero" coeff deduced from already *quantized*
	coefficient, not the original fdct ones.
	This makes a *big* difference ..... in speed :)
	Well, otherwise, there's a very rare possibility that
	including the (first,say) zeroed trailing dct coeffs in the
	optimization might give a better LAST run. I've roughtly
	measured this effect by a tremendous 0.01dB gain @ 200kbps.
	Speed drop is ~15x-20x. wow :)

	bye!
		Skal