[vorbis] Uncoupled mode?

Owen Emry
2002-07-15T17:03:15Z

Craig Dickson wrote:

> Owen Emry wrote:
>
> > FYI I tried this yesterday with RC3 and found the resulting
> ogg files
> > to be substantially smaller if I removed one channel from the input
> > wave file first. These were mono recordings that were
> ripped from a CD
> > -- each channel was bit-identical. I can post actual
> numbers if anyone
> > is interested or surprised -- the files are at home.
>
> Is the bit-identity of the two channels something you
> actually verified
> somehow, or is it an assumption?

They really are identical.  A quick way to verify, btw, is to invert one
channel and mix it into the other, and see if you end up with a whole lotta
zeros.  :)

I used RC3, and at -q 5 the 2-channel wave file ended up at around 80 kbps,
and the the 1-channel wave file was on the order of 50 kbps.  Source was an
ancient recording of Fred Astaire, which is why I presume it compressed down
so much even at q5.

-Owen