steveu at coppice.org
Sun Jan 14 03:49:34 PST 2001
Segher Boessenkool wrote:
> [good piece snipped]
> > The list is quite long.
> You forgot the biggie :-)
> We can't hear phase differences above 2kHz.
Actually I think we both forgot the biggie - "well". We can't detect bass
direction well. We can't detect mid to high range phase well. In fact, we
aren't totally unable to detect most of these things, and when our ears latch on
to the defects they tend to focus on them - at least mine do.
The phase thing is kind of interesting. If you have ever worked with a source of
complex data, like radars and some sonars do, you will know the
aliasing band is the same as the sampling rate, instead of half it. The whole
world of signalling processing looks interestingly different, and seems quite
alien to those who have never tried it. Fun stuff.
> > Current compressors exploit a number of limitations, but none is yet clever
> > enough to exploit them all. That leaves lots of room for fun research!
> The current codecs don't exploit the things they do to full
> extent, either.
> A nice paper to read:
> "Ein psychophysiologisches Gehoermodell zur Nachbildung von
> Wahrnehmungsschwellen fuer die Audiocodierung"
> It's the dissertation of Frank Baumgarte.
Can you point to an English or Chinese translation of that? I'm Germanically
--- >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