[vorbis-dev] Why Point-Stereo at 160 kbps ?

Monty xiphmont at xiph.org
Tue Jul 30 13:37:42 PDT 2002



On Tue, Jul 30, 2002 at 04:02:15PM +0200, Sebastian Gesemann wrote:
> 
> Hi there !
> 
> I checked Vorbis' performace for mono files at
> approx. 64-80 kbps (it does a good job) and I'm 
> wondering why the current OggEnc still uses
> Point-Stereo (>10kHz) for -q4 and -q5

-q4 is currently ~128kbps.  Without point stereo it would be about 180kbps.

> I know, we're usually unable to percieve those
> phase correlations above 10 kHz, But a
> Dolby Prologic Decoder isn't.

Hiding surround encoding in the inadible parts of an audio signal is
so far outside the Vorbis design spec it's hard to know where to
begin.  I'll say this: the whole point of a lossy perceptual encoder
is to lose what you can't hear.

> I think a future version of OggEnc which is able
> to use a user-selectable stereo mode would be graet.

Such a switch will be implemented, promise.

Monty

<p>--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to 'vorbis-dev-request at xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is needed.
Unsubscribe messages sent to the list will be ignored/filtered.



More information about the Vorbis-dev mailing list