Getting average power / peak power (sound monitoring)

FROM : Neil Clayton
DATE : Mon Jun 19 21:45:48 2006

Hi all.

Does anyone know how to get a level (avg power, peak power) meter 
reading from some kind of sound input device?
Ala - the Sound settings panel, in System Preferences (whizzy moving 
level meter).

I've looked at CoreAudio - but there's loads of code, to setup 
AUGraphs, mixers, AUnits etc etc etc. It seems completely overkill. 
And it takes 4% CPU while running (which seems extreeme, just to 
monitor a level).  Quicktime is even less performant (15% CPU time, 
while performing an SGPreview on the audio channel of a 
SequenceGrabber).

Anyone know another way? or done this in the past?

---
Neil Clayton