[XviD-devel] Multithreaded encode
suxen_drol
xvid-devel@xvid.org
Fri, 20 Dec 2002 07:37:27 +1100
On Thu, 5 Dec 2002 21:21:15 +0100 (CET) Christoph Lampert <chl@math.uni-bonn.de> wrote:
> On Fri, 20 Dec 2002, suxen_drol wrote:
>
> >
> > On Thu, 5 Dec 2002 14:11:35 +0100 (CET) Christoph Lampert <chl@math.uni-bonn.de> wrote:
> > >
> > > Can any of you tell me the latest results when using the
> > > fixed quant 2 file from first pass as input for second pass?
>
> > its already implemented in the xvid vfw gui.
> > this method of encoding is generally used to improve speed. it is
> > quicker to decode mpeg-4 than decode/resize/filter mpeg-2, but there is
> > some minor visual quality loss.
>
> Quality loss compared to what? Or, with other words, is this a _visible_
> loss or just lower PSNR?
minor *visible* loss (softer image)..
> Because most people would consider a perfect reproduction of the quant 2
> file just as good as a perfect reproduction of the original, even though
> PSNR would differ.
at quant 2 the dct coeffs are divided by 4. on the second pass, the loss
is compounded. ive done no psnr testing.
-- pete; life is like a box of ammo