[FFmpeg-devel] [PATCH] Add a G.722 encoder

[Martin Storsjö]

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.

// Martin