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@@ -41,7 +41,7 @@ |
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>Many optimizations have been done to the [YIN] algorithm for frequencies between 29-360Hz. |
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>>While its still using a brute force method ( n<sup>2</sup> ) for finding the fundamental frequency f<sub>o</sub>, it is tuned to skip certain <b>tau</b> (<img src="http://rogercortesi.com/eqn/tempimagedir/eqn2874.jpg"/>) values and focus mostly on frequencies found in the bass and guitar. |
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>>While its still using a brute force method ( n<sup>2</sup> ) for finding the fundamental frequency f<sub>o</sub>, it is tuned to skip certain <b>tau</b> (<img src="http://rogercortesi.com/eqn/tempimagedir/eqn7483.png"/></img>) values and focus mostly on frequencies found in the bass and guitar. |
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>>>The input is double buffered so while you are processing one buffer it is filling the other to double throughput. |
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>>>>There are a few parameters that can be adjusted to "dial in" the algorithm for better estimations. The defaults are what I found that have the best trade off for speed and accuracy. |
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@@ -86,11 +86,11 @@ SAMPLE_SKIP --> This sets your sample window length and sampling rate. Sample Wi |
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<div> |
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<b>YIN Algorithm</b> |
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<ol> |
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<li><b>Difference Function -</b> Squared difference of the (signal - signal lag(<img src="http://rogercortesi.com/eqn/tempimagedir/eqn2874.jpg"/>))</li> |
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<li><b>Difference Function -</b> Squared difference of the (signal - signal lag(<img src="http://rogercortesi.com/eqn/tempimagedir/eqn7483.png"/></img>))</li> |
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<img src="http://rogercortesi.com/eqn/tempimagedir/eqn1752.png" /> |
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<li><b>Cumulative Mean Normalized Difference Function -</b> Calculate the cumulative mean on the normalized difference signal</li> |
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<img src="http://rogercortesi.com/eqn/tempimagedir/eqn3269.png" /> |
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<li><b>Absolute Threshold -</b> Fix for subharmonic error with Autocorrelation, choose (<img src="http://rogercortesi.com/eqn/tempimagedir/eqn2874.jpg"/>) that gives a minimum <img src="http://rogercortesi.com/eqn/tempimagedir/eqn3518.png"/></li> |
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<li><b>Absolute Threshold -</b> Fix for subharmonic error with Autocorrelation, choose (<img src="http://rogercortesi.com/eqn/tempimagedir/eqn7483.png"/></img>) that gives a minimum <img src="http://rogercortesi.com/eqn/tempimagedir/eqn3518.png"/></li> |
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</ol> |
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</div> |
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