[FFmpeg-devel] [PATCH] Add a G.722 encoder
Fri Sep 10 15:28:53 CEST 2010
On Fri, 10 Sep 2010, Michael Niedermayer wrote:
> On Fri, Sep 10, 2010 at 04:24:00PM +0300, Martin Storsj? wrote:
> > Hi,
> > As in $subj, the first patch adds a straightforward encoder that produces
> > bitexact output matching the reference test vectors. The second patch adds
> > trellis support to the encoder, closely modelled after the code in
> > libavcodec/adpcm.c.
> > I'm only doing trellis on the lower sub-band, since the higher only is
> > encoded with 2 bits. And if I'd want to do trellis for both of them at the
> > same time, I'd have to run the QMF on the output from both subbands in
> > order to get one decoded sample values, in order to have one difference
> > instead of two to compare.
> why not comapare 2 ?
> diff= (a0-a1)^2 + C*(b0-b1)^2
I guess that's doable, too, I'll try that.
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