[PD] adc - bang

Mathieu Bouchard matju at artengine.ca
Thu Dec 20 19:10:14 CET 2007


On Thu, 20 Dec 2007, Rebecca Schatz wrote:

> Sorry if someone has asked this before but I want a certain audio input 
> frequency (using adc) to cause a bang to occur (i.e. if someone shouts 
> into the mic, this will set off a bang), any ideas?

If you only need to pick one frequency at a time, use [fiddle~]. That's 
what I did to pick up any of 7 synchronisation tones at the beginning of 
videos that lasted several minutes each (of various lengths). The 
probability of 2 at a time was low enough that it was ok to have some 
beeps go unnoticed (it was only to prevent long-term drift).

After you use [fiddle~], you'd use something like [sel] or [moses]. If you 
use [sel] then you should round your values. when you have a midi note, 
add [+ 0.5] and then [i] to round to the closest note.

If you need to pick many notes at once, you could use FFT, but it gets 
complicated when you need much precision on the frequency, as FFT needs a 
lot of latency to figure out frequencies accurately. Depending on what you 
do, "a lot" might be acceptable.

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| Mathieu Bouchard - tél:+1.514.383.3801, Montréal QC Canada


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