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copied!<h1>Working beat detection code (NumPy / PyAudio)</h1> <p>If you are using NumPy this code might help. It assumes the signal (read with PyAudio) is 16-bit wide Int. If that is not the case change or remove the signal.astype() and adjust the normalization-divider (max int16 here).</p> <pre><code>class SimpleBeatDetection: """ Simple beat detection algorithm from http://archive.gamedev.net/archive/reference/programming/features/beatdetection/index.html """ def __init__(self, history = 43): self.local_energy = numpy.zeros(history) # a simple ring buffer self.local_energy_index = 0 # the index of the oldest element def detect_beat(self, signal): samples = signal.astype(numpy.int) # make room for squares # optimized sum of squares, i.e faster version of (samples**2).sum() instant_energy = numpy.dot(samples, samples) / float(0xffffffff) # normalize local_energy_average = self.local_energy.mean() local_energy_variance = self.local_energy.var() beat_sensibility = (-0.0025714 * local_energy_variance) + 1.15142857 beat = instant_energy > beat_sensibility * local_energy_average self.local_energy[self.local_energy_index] = instant_energy self.local_energy_index -= 1 if self.local_energy_index < 0: self.local_energy_index = len(self.local_energy) - 1 return beat </code></pre> <p>The PyAudio examples for wav read or mic record will give you the needed signal data. Create a NumPy array efficiently with <code>frombuffer()</code></p> <pre><code>data = stream.read(CHUNK) signal = numpy.frombuffer(data, numpy.int16) </code></pre>

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