Help/UGens/FFT/PV_HainsworthFoote.html

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  30 <p class="p1"><b>PV_HainsworthFoote</b></p>
  31 <p class="p2"><br></p>
  32 <p class="p3">FFT onset detector based on work described in<span class="Apple-converted-space"> </span></p>
  33 <p class="p2"><br></p>
  34 <p class="p3">Hainsworth, S. (2003) Techniques for the Automated Analysis of Musical Audio. PhD, University of Cambridge engineering dept. See especially p128. The Hainsworth metric is a modification of the Kullback Liebler distance.<span class="Apple-converted-space"> </span></p>
  35 <p class="p2"><br></p>
  36 <p class="p3">The onset detector has general ability to spot spectral change, so may have some ability to track chord changes<span class="Apple-converted-space">  </span>aside from obvious transient jolts, but there's no guarantee it won't be confused by frequency modulation artifacts.<span class="Apple-converted-space">   </span></p>
  37 <p class="p2"><br></p>
  38 <p class="p3">Hainsworth metric on it's own gives good results but Foote might be useful in some situations: experimental.<span class="Apple-converted-space"> </span></p>
  39 <p class="p2"><br></p>
  40 <p class="p2"><br></p>
  41 <p class="p3"><b>*ar(buffer, proph=0.0, propf=0.0, threshold=1.0, waittime=0.04)</b></p>
  42 <p class="p2"><br></p>
  43 <p class="p3"><b>buffer-</b> FFT buffer to read from</p>
  44 <p class="p2"><br></p>
  45 <p class="p3"><b>proph-</b> What strength of detection signal from Hainsworth metric to use.</p>
  46 <p class="p2"><br></p>
  47 <p class="p3"><b>propf-</b> What strength of detection signal from Foote metric to use. The Foote metric is normalised to [0.0,1.0]</p>
  48 <p class="p2"><br></p>
  49 <p class="p3"><b>threshold-</b> Threshold hold level for allowing a detection</p>
  50 <p class="p2"><br></p>
  51 <p class="p3"><b>waittime-</b> If triggered, minimum wait until a further frame can cause another spot (useful to stop multiple detects on heavy signals)</p>
  52 <p class="p2"><br></p>
  53 <p class="p4"><span class="s1">See also <a href="FFT Overview.html"><span class="s2">FFT Overview</span></a>.</span></p>
  54 <p class="p2"><br></p>
  55 <p class="p5"><br></p>
  56 <p class="p5"><br></p>
  57 <p class="p6">// Examples</p>
  58 <p class="p7"><br></p>
  59 <p class="p7"><br></p>
  60 <p class="p6">// just Hainsworth metric with low threshold</p>
  61 <p class="p8">// external sound in</p>
  62 <p class="p9">(</p>
  63 <p class="p9">{</p>
  64 <p class="p9"><span class="Apple-tab-span">     </span><span class="s3">var</span> source1, signal, detect;</p>
  65 <p class="p7"><span class="Apple-tab-span">     </span></p>
  66 <p class="p9"><span class="Apple-tab-span">     </span>source1 = <span class="s3">SoundIn</span>.ar(0);</p>
  67 <p class="p9"><span class="Apple-tab-span">     </span>detect = <span class="s3">PV_HainsworthFoote</span>.ar(<span class="s3">FFT</span>(<span class="s3">LocalBuf</span>(2048), source1), 1.0, 0.0);</p>
  68 <p class="p9"><span class="Apple-tab-span">     </span>signal = <span class="s3">SinOsc</span>.ar([440,445], 0, <span class="s3">Decay</span>.ar(0.1 * detect, 0.1));</p>
  69 <p class="p10"><span class="s1"><span class="Apple-tab-span">   </span></span>signal</p>
  70 <p class="p9">}.play;<span class="Apple-tab-span">      </span></p>
  71 <p class="p9">)<span class="Apple-tab-span">    </span></p>
  72 <p class="p7"><br></p>
  73 <p class="p7"><br></p>
  74 <p class="p11"><br></p>
  75 <p class="p8">// spot note transitions<span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span></p>
  76 <p class="p12">(</p>
  77 <p class="p12">{</p>
  78 <p class="p12"><span class="Apple-converted-space"> </span><span class="s4">var</span> source1, signal, detect;</p>
  79 <p class="p11"><span class="Apple-tab-span">    </span></p>
  80 <p class="p12"><span class="Apple-tab-span">    </span>source1 = <span class="s4">LFSaw</span>.ar(<span class="s4">LFNoise0</span>.kr(1, 90, 400), 0, 0.5);</p>
  81 <p class="p12"><span class="Apple-tab-span">    </span>detect = <span class="s4">PV_HainsworthFoote</span>.ar(<span class="s4">FFT</span>(<span class="s4">LocalBuf</span>(2048), source1), 1.0, 0.0, 0.9, 0.5);</p>
  82 <p class="p12"><span class="Apple-tab-span">    </span>signal = <span class="s4">SinOsc</span>.ar(440, 0, <span class="s4">Decay</span>.ar(0.1 * detect, 0.1));</p>
  83 <p class="p12"><span class="Apple-tab-span">    </span>[source1, signal];</p>
  84 <p class="p12">}.play;<span class="Apple-tab-span">     </span></p>
  85 <p class="p12">)</p>
  86 <p class="p11"><br></p>
  87 <p class="p8">// not so sucessful with this test sound:<span class="Apple-converted-space"> </span></p>
  88 <p class="p8">// mouse y is difficulty, mouse x is threshold</p>
  89 <p class="p12">(</p>
  90 <p class="p12">{</p>
  91 <p class="p12"><span class="Apple-tab-span">    </span><span class="s4">var</span> source1, detect, difficulty, rate, trig, n = 20;</p>
  92 <p class="p12"><span class="Apple-tab-span">    </span>rate = <span class="s4">LFNoise1</span>.kr(0.3).exprange(1, 5);</p>
  93 <p class="p12"><span class="Apple-tab-span">    </span>difficulty = <span class="s4">MouseY</span>.kr(0, 1);</p>
  94 <p class="p12"><span class="Apple-tab-span">    </span>trig = <span class="s4">Impulse</span>.kr(rate);</p>
  95 <p class="p12"><span class="Apple-tab-span">    </span>source1 = { <span class="s4">|i|</span></p>
  96 <p class="p12"><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span><span class="s4">var</span> t = <span class="s4">CoinGate</span>.kr(1 - difficulty, trig);</p>
  97 <p class="p12"><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span><span class="s4">SinOsc</span>.ar(<span class="s4">TExpRand</span>.kr(300, 1000, t) * (i + 1)) * <span class="s4">TRand</span>.kr(0, 1, t)<span class="Apple-converted-space"> </span></p>
  98 <p class="p12"><span class="Apple-tab-span">    </span>}.dup(10).sum;</p>
  99 <p class="p8"><span class="s1"><span class="Apple-tab-span">    </span></span>// source1 = source1 * Decay.kr(trig, 0.5);</p>
 100 <p class="p12"><span class="Apple-tab-span">    </span>detect = <span class="s4">PV_HainsworthFoote</span>.ar(<span class="s4">FFT</span>(<span class="s4">LocalBuf</span>(2048), source1), threshold: <span class="s4">MouseX</span>.kr(0.01, 1.0));</p>
 101 <p class="p12"><span class="Apple-tab-span">    </span><span class="s4">WhiteNoise</span>.ar * <span class="s4">Decay</span>.ar(detect, 0.1) + (source1 * 0.2);</p>
 102 <p class="p12">}.play;<span class="Apple-tab-span">     </span></p>
 103 <p class="p12">)</p>
 104 <p class="p11"><br></p>
 105 <p class="p11"><br></p>
 106 <p class="p6">// tests using sound in</p>
 107 <p class="p7"><br></p>
 108 <p class="p6">// Foote solo - never triggers with threshold over 1.0, threshold under mouse control</p>
 109 <p class="p5"><span class="Apple-tab-span">     </span></p>
 110 <p class="p9">(</p>
 111 <p class="p9">{</p>
 112 <p class="p9"><span class="Apple-converted-space"> </span><span class="s3">var</span> source1, signal, detect;</p>
 113 <p class="p7"><span class="Apple-tab-span">     </span></p>
 114 <p class="p9"><span class="Apple-tab-span">     </span>source1 = <span class="s3">SoundIn</span>.ar(0);<span class="Apple-converted-space"> </span></p>
 115 <p class="p7"><span class="Apple-tab-span">     </span></p>
 116 <p class="p9"><span class="Apple-tab-span">     </span>detect = <span class="s3">PV_HainsworthFoote</span>.ar(<span class="s3">FFT</span>(<span class="s3">LocalBuf</span>(2048), source1), 0.0, 1.0,<span class="Apple-converted-space"> </span></p>
 117 <p class="p9"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span><span class="s3">MouseX</span>.kr(0.0,1.1), 0.02);</p>
 118 <p class="p9"><span class="Apple-tab-span">     </span>signal = <span class="s3">SinOsc</span>.ar(440, 0, <span class="s3">Decay</span>.ar(0.1 * detect, 0.1));</p>
 119 <p class="p9"><span class="Apple-tab-span">     </span>[source1, signal];</p>
 120 <p class="p9">}.play;<span class="Apple-tab-span">      </span></p>
 121 <p class="p9">)</p>
 122 <p class="p7"><br></p>
 123 <p class="p7"><br></p>
 124 <p class="p6">// compare to Amplitude UGen</p>
 125 <p class="p9">(</p>
 126 <p class="p9">{</p>
 127 <p class="p9"><span class="Apple-converted-space"> </span><span class="s3">var</span> source1, signal, detect;</p>
 128 <p class="p7"><span class="Apple-tab-span">     </span></p>
 129 <p class="p9"><span class="Apple-tab-span">     </span>source1= <span class="s3">SoundIn</span>.ar(0);<span class="Apple-converted-space"> </span></p>
 130 <p class="p7"><span class="Apple-tab-span">     </span></p>
 131 <p class="p9"><span class="Apple-tab-span">     </span>detect= (<span class="s3">Amplitude</span>.ar(source1)) &gt; (<span class="s3">MouseX</span>.kr(0.0,1.1));</p>
 132 <p class="p9"><span class="Apple-tab-span">     </span>signal = <span class="s3">SinOsc</span>.ar(440, 0, <span class="s3">Decay</span>.ar(0.1 * detect, 0.1));</p>
 133 <p class="p9"><span class="Apple-tab-span">     </span>[source1, signal];</p>
 134 <p class="p9">}.play;<span class="Apple-tab-span">      </span></p>
 135 <p class="p9">)</p>
 136 <p class="p7"><br></p>
 137 <p class="p7"><br></p>
 138 <p class="p7"><br></p>
 139 <p class="p7"><br></p>
 140 <p class="p7"><br></p>
 141 <p class="p7"><br></p>
 142 <p class="p7"><br></p>
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