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import subprocess
def get_encoding(dtype):
encodings = {
'float32': 'floating-point',
'int32': 'signed-integer',
'int16': 'signed-integer',
'uint8': 'unsigned-integer',
}
return encodings[dtype]
def get_bit_depth(dtype):
bit_depths = {
'float32': 32,
'int32': 32,
'int16': 16,
'uint8': 8,
}
return bit_depths[dtype]
def gen_audio_file(
path, sample_rate, num_channels,
*, encoding=None, bit_depth=None, compression=None, attenuation=None, duration=1,
):
"""Generate synthetic audio file with `sox` command."""
if path.endswith('.wav'):
raise RuntimeError(
'Use get_wav_data and save_wav to generate wav file for accurate result.')
command = [
'sox',
'-V3', # verbose
'-R',
# -R is supposed to be repeatable, though the implementation looks suspicious
# and not setting the seed to a fixed value.
# https://fossies.org/dox/sox-14.4.2/sox_8c_source.html
# search "sox_globals.repeatable"
]
if bit_depth is not None:
command += ['--bits', str(bit_depth)]
command += [
'--rate', str(sample_rate),
'--null', # no input
'--channels', str(num_channels),
]
if compression is not None:
command += ['--compression', str(compression)]
if bit_depth is not None:
command += ['--bits', str(bit_depth)]
if encoding is not None:
command += ['--encoding', str(encoding)]
command += [
str(path),
'synth', str(duration), # synthesizes for the given duration [sec]
'sawtooth', '1',
# saw tooth covers the both ends of value range, which is a good property for test.
# similar to linspace(-1., 1.)
# this introduces bigger boundary effect than sine when converted to mp3
]
if attenuation is not None:
command += ['vol', f'-{attenuation}dB']
print(' '.join(command))
subprocess.run(command, check=True)
def convert_audio_file(
src_path, dst_path,
*, bit_depth=None, compression=None):
"""Convert audio file with `sox` command."""
command = ['sox', '-V3', '-R', str(src_path)]
if bit_depth is not None:
command += ['--bits', str(bit_depth)]
if compression is not None:
command += ['--compression', str(compression)]
command += [dst_path]
print(' '.join(command))
subprocess.run(command, check=True)
def _flattern(effects):
if not effects:
return effects
if isinstance(effects[0], str):
return effects
return [item for sublist in effects for item in sublist]
def run_sox_effect(input_file, output_file, effect, *, output_sample_rate=None, output_bitdepth=None):
"""Run sox effects"""
effect = _flattern(effect)
command = ['sox', '-V', '--no-dither', input_file]
if output_bitdepth:
command += ['--bits', str(output_bitdepth)]
command += [output_file] + effect
if output_sample_rate:
command += ['rate', str(output_sample_rate)]
print(' '.join(command))
subprocess.run(command, check=True)
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