Audio Encoding Ideas [WAS: Re: Optimize my code...]

["Neil" <dreaded.neil@phreaker.net>]

<snip>
> them coming! Any chance the next topic will be audio compression? ;-)
> That's what I do right now, and its giving me a lot of headaches.....
> Anyway, if anyone know cool pages/tutorials on it (especially MP3-like
> compression) please drop me an email....

I know absolutely nothing about the techniques used for audio compression.
Since you're interested, however, I would like to throw out some ideas of
mine. They probably either suck or are already used, but I'd like someone
else to know about them before I forget. I assume that one method would be
to encode the data like gif, pcx, etc. image files via a linear
byte-by-byte method. However, sound has definate properties of curves, as
far as I know, which might be used to great advantage. Suppose that you
tried a regression technique to generate a (very complex) equation of the
sound which could be stored rather than the data, then re-created the sound
later from the equation. Another method could be to find (I don't know how)
key nodes in the sounds' shape and use them to re-create the sound. The
frequency of the nodes would affect the accuracy. A curve could be found
passing thrpugh the nodes (Perhaps storing the angle at which the line
crosses each node with it would help) to recreate the data. My final idea
would be to try breaking down the sound into as many sine waves as are
contained therein (Possibly be repeatedly trying over and over to get the
right combination). You would need only know their properties (frequency,
phase) and the points at which their amplitudes peak and hit zero.
Recombining them all would (maybe) yield the original sound, or close to
it. I hope my ignorance in this matter hasn't caused me to say things that
are TOO stupid, but from my totally never-heard-anything-about-this-before
approach, that's how _I_ would first try to do it. I'd like to know how
MP3's et al really are encoded.
-- Neil Edelman
-- ICQ UIN: 705130
-- email: mailto:dreaded.neil@phreaker.net?subject=sig
-- home: http://members.xoom.com/dreadedneil
-- about: http://members.xoom.com/dreadedneil/author
-- "My air-to-air missile overrides your air traffic control clearance"

=================================================================
The GameProgrammer.Com mailing list is for the open discussion
of any topic related to the art, science, and business of
programming games. This list is especially tolerant of beginners.
We were all beginners once

To SUBSCRIBE or UNSUBSCRIBE please visit:
http://gameprogrammer.com/mailinglist.html