[vorbis-dev] Some very early RC1 results

[Monty]

On Sun, Jul 15, 2001 at 02:32:11AM +0200, Gian-Carlo Pascutto wrote:
> Hi all,
> 
> I started testing the RC1 encoder at
> 
> ftp://sjeng.sourceforge.net/pub/sjeng/oggdrop.exe
> 
> (based on branch_monty_20010708)
> 
> On the songs I have tested so far (not much :)
> I did not hear any stereo issues, but there are 
> some very noticeable problems with the produced files.
> 
> Songs without much high-end will suddenly have one
> when encoded. (you'd expect it the other way around)
> It nearly sounds as if the encoder adds 'hiss'.

Actually, what I think you're describing is that hiss from across the
stereo image is being moved/concentrated in the center by the >4kHz
point stereo.  In the process of doing so, the encoder is not
accounting for the increase in noise energy because the polar mapping
isn't circular (an energy of .5 is becoming a total energy of 1. when
the hiss is centered).  Both aspects of the problem can be controlled,
the current encoder doesn't try.

Does that sound about like what you're hearing?

Monty

--- >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.