source: tests/create_tests_source.py @ 276032d

feature/autosinkfeature/constantqfeature/pitchshiftfeature/timestretch
Last change on this file since 276032d was b610be5, checked in by Paul Brossier <piem@piem.org>, 12 months ago

[tests] pure python create_sine_wave

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File size: 1.2 KB
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[703cc2b]1#! /usr/bin/env python
2
3""" Create a simple stereo file containing a sine tone at 441 Hz, using only
[b610be5]4python's built-in modules. """
[703cc2b]5
6import wave
[b610be5]7import math
8import struct
[703cc2b]9
10
11def create_sine_wave(freq, samplerate, nframes, nchannels):
[b610be5]12    """ create a pure tone (without numpy) """
13    _x = [0.7 * math.sin(2. * math.pi * freq * t / float(samplerate))
14          for t in range(nframes)]
15    _x = [int(a * 32767) for a in _x]
16    _x = b''.join([b''.join([struct.pack('h', v)
17                             for _ in range(nchannels)])
18                   for v in _x])
19    return _x
[703cc2b]20
21
22def create_test_sound(pathname, freq=441, duration=None,
[b610be5]23                      framerate=44100, nchannels=2):
[703cc2b]24    """ create a sound file at pathname, overwriting exiting file """
[b610be5]25    sampwidth = 2
[703cc2b]26    nframes = duration or framerate  # defaults to 1 second duration
27    fid = wave.open(pathname, 'w')
28    fid.setnchannels(nchannels)
29    fid.setsampwidth(sampwidth)
30    fid.setframerate(framerate)
31    fid.setnframes(nframes)
32    frames = create_sine_wave(freq, framerate, nframes, nchannels)
[b610be5]33    fid.writeframes(frames)
[703cc2b]34    fid.close()
35    return 0
36
37
38if __name__ == '__main__':
39    import sys
40    if len(sys.argv) < 2:
41        sys.exit(2)
42    sys.exit(create_test_sound(sys.argv[1]))
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