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<html> | ||
<head> | ||
<script language="javascript" src="js/processing.js"></script> | ||
<script language="javascript" src="js/init.js"></script> | ||
<script language="javascript" src="../dsp.js"></script> | ||
</head> | ||
<body> | ||
<style> | ||
body { background: black; margin:0; padding:0;} | ||
</style> | ||
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<script> | ||
var frameBufferSize = 4096; | ||
var bufferSize = frameBufferSize/2; | ||
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var signal = new Float32Array(bufferSize); | ||
var peak = new Float32Array(bufferSize); | ||
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var fft = new RFFT(bufferSize, 44100); | ||
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function loadedMetaData(event) { | ||
var audio = document.getElementById('input'); | ||
audio.mozFrameBufferLength = frameBufferSize; | ||
audio.addEventListener("MozAudioAvailable", audioAvailable, false); | ||
} | ||
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function audioAvailable(event) { | ||
// deinterleave and mix down to mono | ||
signal = DSP.getChannel(DSP.MIX, event.frameBuffer); | ||
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// perform forward transform | ||
fft.forward(signal); | ||
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// calculate peak values | ||
for ( var i = 0; i < bufferSize; i++ ) { | ||
fft.spectrum[i] *= -1 * Math.log((fft.bufferSize/2 - i) * (0.5/fft.bufferSize/2)) * fft.bufferSize; // equalize, attenuates low freqs and boosts highs | ||
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if ( peak[i] < fft.spectrum[i] ) { | ||
peak[i] = fft.spectrum[i]; | ||
} else { | ||
peak[i] *= 0.99; // peak slowly falls until a new peak is found | ||
} | ||
} | ||
} | ||
</script> | ||
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<script target="#fft" type="application/processing"> | ||
void setup() { | ||
size(1400, 600); | ||
colorMode(HSB, 360, 100, 100); | ||
strokeWeight(3); | ||
frameRate(60); | ||
//strokeCap(SQUARE); | ||
} | ||
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void draw() { | ||
background(0); | ||
//fill(0, 60); | ||
//rect(0, 0, width, height); | ||
for ( int i = 0; i < fft.spectrum.length/2; i += 3 ) { | ||
if (3 * i > width) { break; } | ||
var magnitude = fft.spectrum[i]; | ||
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// draw magnitudes | ||
stroke((i) % 360, 60, constrain(magnitude * 6, 20, 100)); | ||
line(3*i, height, 3*i, height - magnitude * 16); | ||
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// draw peak indicators | ||
stroke((i) % 360, 60, constrain(magnitude * 100, 50, 100)); | ||
line(3*i, height - peak[i] * 16 - 1, 3*i, height - peak[i] * 16); | ||
} | ||
/* | ||
if (frameCount % 100 == 0 ) { | ||
println(FRAME_RATE); | ||
} | ||
*/ | ||
} | ||
</script> | ||
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<audio id="input" src="audio/corban-peddle.ogg" controls="true" onloadedmetadata="loadedMetaData(event);"></audio><br /> | ||
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<div><canvas id="fft"></canvas></div> | ||
</body> | ||
</html> |