Sound Input Meter (Or, getting amplitude of input stream)

FROM : Olivier Lanctôt
DATE : Thu Apr 14 21:08:12 2005

Hello list...

First, I want to say that it's really a major pain to record sound in
Cocoa. Really. Anyway, I can sucessfully record from the sound input
to AIFF... which is an important part of my app.

But when recording, I think the user should have a visual feedback of
the input's amplitude (e.g. sound meters...)
So I look in sound kit and ... what a bad luck, the method is "not yet
implemented" (will it ever be implemented? I think not.... the email I
sent the author has bounced.)

/*!
    @method  getPeakLeft:right:
    @abstract  Get the most recent peak values for the stereo stream
    @discussion Not implemented yet - not convinced this should be
here - maybe inside an SndAudioProcessor?
    @param      leftPeak Left peak value
    @param      rightPeak Righ peak value
    @result    Returns self.
*/
- getPeakLeft: (float *) leftPeak right: (float *) rightPeak;

So without that, I can't get the amplitude of a sound... So I looked
at QT code.. but all I've seen is old SoundManager code (sigh). I've
carefully inspected MTCoreAudio too -- found nothing that could have
helped me.

So where do I look next?

Thanks!

-- Jean-Olivier Lanctôt-D.
Programmer
Cliché Software
http://www.clichesw.com