[linux-audio-dev] FOSS-tools for realtime audio analysis?

[carmen]

On Wed, Apr 06, 2005 at 03:00:45PM +0200, Alfons Adriaensen wrote:
> On Wed, Apr 06, 2005 at 12:32:20PM +0000, mathias_lundgren at bredband.net wrote:
> 
> > Are there any tools/libraries around which makes it possible to do 
> > something like this? 
> >  
> > 1) Feed an audio signal (f.ex. a sinus wave) into external hardware 
> >  
> > 2) Record the signal returned from the external hardware 
> >  
> > 3) "Compare" the two signals (realtime would be neat, if you know what 
> > latency you have btwn output/input I hope this might be achieved w 
> > Jack) and perform some kind of analysis of what the external hardware 
> > does to the signal (S/N ratio, damping, etc etc). 

in http://whats-your.name/pd/gui/spectrum.gif , the first channel is yellow, the second channel blue, a notch is swept across the frequency range to demonstrate, the attenuated area shows in yellow, the equivalent areas in green, the amplified areas in darker blue..of course the colors are totalyl configurable.

for external hardware youd want to insert a delay between the test signal source and the graph input, and adjust until it matches the external input to account for system latency

> I'm considering some additional functionality, and if you have any
> specific requirements I'd be interested to know.

it would be nice in JAAA to show multiple chans like this, since my 'proof of concept' is in tcl+tkZinc so it chews about 5% of cpu on my AMD64 and presumably more on slower hardware..

also, a spectrogram, just for fun ( http://whats-your.name/pd/gui/sp.gif ), and some sort of RMS with adjustable moving-average length..

carmen