diff options
| -rw-r--r-- | solo-tool-project/src/solo_tool/metronome.py | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/solo-tool-project/src/solo_tool/metronome.py b/solo-tool-project/src/solo_tool/metronome.py new file mode 100644 index 0000000..d99e0b8 --- /dev/null +++ b/solo-tool-project/src/solo_tool/metronome.py @@ -0,0 +1,73 @@ +import pyaudio as pa +from array import array + +def _createClickSample(clickFrequency: int, samplingRate: int) -> array: + clickDuration = 0.1 # seconds + + sampleLength = int(clickDuration * samplingRate) + fadeSamples = 10 + attackEnv = [i/fadeSamples for i in range(1, fadeSamples, 1)] + releaseEnv = [i/fadeSamples for i in range(fadeSamples, 0, -1)] + amplitudeEnv = attackEnv + [1.0] * (sampleLength - len(attackEnv) - len(releaseEnv)) + releaseEnv + cycleLength = (1 / clickFrequency) * samplingRate + + from math import sin, pi + return array('h', [int(sin(((i % cycleLength) / cycleLength) * 2 * pi) * amplitudeEnv[i] * 32767) for i in range(sampleLength)]) + +def _createOutputBuffer(bpm: int, clickFrequency: int, samplingRate: int) -> array: + clickSample = _createClickSample(clickFrequency, samplingRate) + samplesPerBeat = int((60 / bpm) * samplingRate) + assert len(clickSample) <= samplesPerBeat + return clickSample + array('h', [0] * (samplesPerBeat - len(clickSample))) + +class Metronome: + def __init__(self, bufferSize: int, samplingRate: int): + self._bufferSize = bufferSize + self._samplingRate = samplingRate + self._sampleFormat = pa.paInt16 + self._channels = 1 + self._pa = pa.PyAudio() + self._stream = None + self._bufferPointer = 0 + self._outputBuffer = array('h') + + def __del__(self): + if self.running: + self._stream.stop_stream() + self._stream.close() + + def _callback(self, inData, frameCount, timeInfo, statusFlags): + leftover = len(self._outputBuffer) - self._bufferPointer + if frameCount > leftover: + outData = self._outputBuffer[self._bufferPointer:] + self._outputBuffer[0:frameCount - leftover] + self._bufferPointer = frameCount - leftover + else: + outData = self._outputBuffer[self._bufferPointer:self._bufferPointer + frameCount] + self._bufferPointer += frameCount + assert self._bufferPointer >= 0 and self._bufferPointer <= len(self._outputBuffer) + return (outData.tobytes(), pa.paContinue) + + def start(self, bpm: int, clickFrequency: int) -> None: + if self.running: + return + self._bufferPointer = 0 + self._outputBuffer = _createOutputBuffer(bpm, clickFrequency, self._samplingRate) + self._stream = self._pa.open(format=self._sampleFormat, + channels=self._channels, + rate=self._samplingRate, + frames_per_buffer=self._bufferSize, + output=True, + stream_callback=self._callback) + + def stop(self) -> None: + if not self.running: + return None + + self._stream.stop_stream() + self._stream.close() + self._stream = None + + @property + def running(self) -> bool: + return self._stream is not None + |