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

Michael Niedermayer michaelni
Fri Sep 10 15:27:15 CEST 2010


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

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

If a bugfix only changes things apparently unrelated to the bug with no
further explanation, that is a good sign that the bugfix is wrong.
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