[FFmpeg-devel] [PATCH] g722: Add a trellis encoder

[Martin Storsjö]

On Fri, 3 Dec 2010, Michael Niedermayer wrote:

> On Wed, Dec 01, 2010 at 02:03:17PM +0200, Martin Storsj? wrote:
> > On Wed, 1 Dec 2010, Martin Storsj? wrote:
> > 
> > > Now that most (all?) issues with the normal adpcm trellis encoder have 
> > > been sorted out, here's an updated version of the g722 trellis encoder, 
> > > with all the changes from the adpcm trellis encoder incorporated.
> > 
> 
> > As Tomas H?rdin suggested on irc, the lower and upper subbands could be
> > optimized totally independently from each other with a separate trellis. I
> 
> i thought i had suggested that ages ago alraedy ...

Hmm, you might have - I probably didn't understand exactly how you meant 
it should be implemented, and didn't think of this version, so I did it in 
an inferior way. When discussing it on irc with Tomas the other day, I 
realized that this is a better way of solving it.

> > implemented this, making it run faster and giving better output. 
> > (Previously, I ran one trellis, where each combination of lower and upper 
> > subband codewords were tested as a whole, but still by summing their ssds. 
> > Since they don't affect each other, they can be optimized separately.)
> > 
> > Thus, updated patch attached.
> > 
> > // Martin
> >  g722.c |  198 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 198 insertions(+)
> > 5b8d7fe6a920fa9d2b3686802f2d9ebd1edb7be2  0001-g722-Add-a-trellis-encoder.patch
> > From 19b65df2f43c427beb64cb57095e31ed8ca58f1c Mon Sep 17 00:00:00 2001
> > From: Martin Storsjo <martin at martin.st>
> > Date: Fri, 10 Sep 2010 15:55:52 +0300
> > Subject: [PATCH] g722: Add a trellis encoder
> > 
> > It is to a large extent built similarly to the normal adpcm trellis
> > encoder.
> > ---
> >  libavcodec/g722.c |  198 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  1 files changed, 198 insertions(+), 0 deletions(-)
> 
> we need a maintainer for g722.c
> if you volunteer then i think i dont have to review this :)

Sure, I volunteer to maintain it. Applied then. :-)

Thanks for the valuable feedback in reviewing it!

// Martin