My real-time spectrum analyzer code would be a good place to start. http://www.audiostretch.com/spectrum/
It grabs audio from the mic, applies a Hanning analysis window, does an FFT, converts to a log-magnitude (dB scale) spectrum, and plots the spectrum at regular time intervals. It doesn't go quite so far as extracting the pitch/note, but that's mostly a matter of finding the first big peak in the spectrum, and doing a bit of interpolation around the peak to get sub-FFT-bin accuracy. Code can be found here: http://gerrybeauregard.wordpress.com/2010/08/06/real-time-spectrum-analysis/ It relies on my FFT which can be found here: http://gerrybeauregard.wordpress.com/2010/08/03/an-even-faster-as3-fft/ -Gerry On 2011-11-23 , at 22:11 , allandt bik-elliott wrote: > hey guys > > does anyone have any references / links to help me understand how to > extract the note / tone / pitch from a sound captured from a mic > > i have a view to deal with the mic and i am capturing the output correctly > but i need to understand how to check it for specific pitch ranges > > here is my class so far - i'd like the controller to be able to apply some > logic to decide how the app should respond from there (using > controller.updateAudioSample(audioChunk);) > > [CODE] > package uk.co.publicis.toothbrushdetectorapp.views > { > // imports > ... > public class MicView extends View implements IView > { > private var _mic : Microphone; > public function MicView(model:Model, controller:Controller=null) > { > super(model, controller); > init(); > } > private function init():void > { > if (Microphone.isSupported) > { > _mic = Microphone.getMicrophone(); > _mic.enableVAD = true; > _mic.encodeQuality = 0; > _mic.rate = 8; > } > } > /* INTERFACE uk.co.publicis.toothbrushdetectorapp.views.IView */ > public function destroy():Boolean > { > disable(); > _mic = null; > return true; > } > public function enable():Boolean > { > if (Microphone.isSupported) > { > _mic.addEventListener(ActivityEvent.ACTIVITY, handleActivity); > // odd behaviour - if this is not added here, no ActivityEvent.ACTIVITY > will be captured either. > // makes it impossible to start / stop capturing the SAMPLE_DATA on > ACTIVITY events > _mic.addEventListener(SampleDataEvent.SAMPLE_DATA, handleSampleData); > } > return true; > } > public function disable():Boolean > { > if (Microphone.isSupported) > { > _mic.removeEventListener(ActivityEvent.ACTIVITY, handleActivity); > _mic.removeEventListener(SampleDataEvent.SAMPLE_DATA, handleSampleData); > } > return true; > } > private function handleActivity(e:ActivityEvent):void > { > if (e.activating) > { > controller.activate(); > } > else > { > controller.deactivate(); > } > } > private function handleSampleData(e:SampleDataEvent):void > { > var audioChunk:ByteArray = e.data as ByteArray; > controller.updateAudioSample(audioChunk); > } > public function get model():TBDModel > { > return _model as TBDModel; > } > public function get controller():TBDController > { > return _controller as TBDController; > } > } > } > [/CODE] > > thanks in advance > a > _______________________________________________ > Flashcoders mailing list > [email protected] > http://chattyfig.figleaf.com/mailman/listinfo/flashcoders _______________________________________________ Flashcoders mailing list [email protected] http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
