ref: 6150f81155a70a2ea291b8e54309ecc588e84f33
dir: /tests/create_tests_source.py/
#! /usr/bin/env python """ Create a simple stereo file containing a sine tone at 441 Hz, using only python's built-in modules. """ import wave import math import struct def create_sine_wave(freq, samplerate, nframes, nchannels): """ create a pure tone (without numpy) """ _x = [0.7 * math.sin(2. * math.pi * freq * t / float(samplerate)) for t in range(nframes)] _x = [int(a * 32767) for a in _x] _x = b''.join([b''.join([struct.pack('h', v) for _ in range(nchannels)]) for v in _x]) return _x def create_test_sound(pathname, freq=441, duration=None, framerate=44100, nchannels=2): """ create a sound file at pathname, overwriting exiting file """ sampwidth = 2 nframes = duration or framerate # defaults to 1 second duration fid = wave.open(pathname, 'w') fid.setnchannels(nchannels) fid.setsampwidth(sampwidth) fid.setframerate(framerate) fid.setnframes(nframes) frames = create_sine_wave(freq, framerate, nframes, nchannels) fid.writeframes(frames) fid.close() return 0 if __name__ == '__main__': import sys if len(sys.argv) < 2: sys.exit(2) sys.exit(create_test_sound(sys.argv[1]))