[FFmpeg-cvslog] r12397 - trunk/libavcodec/ac3dec.c

[Rich Felker]

On Sun, Mar 09, 2008 at 05:18:18PM +0000, M?ns Rullg?rd wrote:
> Justin Ruggles <justinruggles at bellsouth.net> writes:
> 
> > jbr wrote:
> >> Author: jbr
> >> Date: Sun Mar  9 18:05:19 2008
> >> New Revision: 12397
> >> 
> >> Log:
> >> downmix before imdct unless different size transforms are used. about 20%
> >> faster 5.1-to-stereo downmixing.
> >
> > But still about 13% slower than liba52.  I don't think it will ever be
> > able to match liba52's speed in downmixing, but at least it's much
> > closer now.
> 
> Why can't it be as fast as liba52?

I don't understand what's meant by "delay samples", but upmixing them
then downmixing them again sounds incredibly misguided. I suspect
linearity makes it totally useless to do these two steps.

Rich