ref: 586383d59c850b76eda3bfcc73b0734126bc6f4d
dir: /tests/create_tests_source.py/
#! /usr/bin/env python
""" Create a simple stereo file containing a sine tone at 441 Hz, using only
numpy and python's native wave module. """
import wave
import numpy as np
def create_sine_wave(freq, samplerate, nframes, nchannels):
""" create a pure tone """
# samples indices
_t = np.tile(np.arange(nframes), (nchannels, 1))
# sine wave generation
_x = 0.7 * np.sin(2. * np.pi * freq * _t / float(samplerate))
# conversion to int and channel interleaving
return (_x * 32767.).astype(np.int16).T.flatten()
def create_test_sound(pathname, freq=441, duration=None,
sampwidth=2, framerate=44100, nchannels=2):
""" create a sound file at pathname, overwriting exiting file """
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.tobytes())
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]))