[Vorbis-dev] Psychoacoustic model

[Monty]

On Fri, Jun 17, 2005 at 03:04:56PM +0530, venkat wrote:
> Hi
> 
> I am trying to understand the psychoacoustic model used in the Oggvorbis 
> encoder by looking at the source. I found it very difficult to understand. 

Part of the problem is that it is, was, and always will be in constant
flux.  There is no universally agreed upon way to do proper
psychoacoustics in the field of audio coding today... just layer after
layer of experiment, incremental advancement and [momentarily]
inexplicable hacks that work.

> Does any one has any idea on this?  Can I get any information on the 
> reference papers (JASA, AES or IEEE ASSP) which can be referred to 
> understand this source code?

The original papers discussing tone/tone and tone/noise masking are a
good start.  Ehmer's papers in the 1950's in the JASA are the original
source of much of the thinking (and hard numbers) in the Vorbis
psychoacoustics, but honestly, this starting point is obsolete in
modern Vorbis encoders.  Vorbis II is moving an entirely different
direction yet again.

> Can I know who is the author of this module?

I am.

Monty