ref: 12e5d8969f8d1e62ca1c7c0fdf311b7d27d18bde
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]))