# Copyright (c) 2013 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
import logging
import re
from autotest_lib.client.cros.audio import cmd_utils
SOX_PATH = 'sox'
def _raw_format_args(channels, bits, rate):
args = ['-t', 'raw', '-e', 'signed']
args += ['-c', str(channels)]
args += ['-b', str(bits)]
args += ['-r', str(rate)]
return args
def generate_sine_tone_cmd(
filename, channels=2, bits=16, rate=48000, duration=None, frequence=440,
gain=None):
"""Gets a command to generate sine tones at specified ferquencies.
@param filename: The name of the file to store the sine wave in.
@param channels: The number of channels.
@param bits: The number of bits of each sample.
@param rate: The sampling rate.
@param duration: The length of the generated sine tone (in seconds).
@param frequence: The frequence of the sine wave.
@param gain: The gain (in db).
"""
args = [SOX_PATH, '-n']
args += _raw_format_args(channels, bits, rate)
args.append(filename)
args.append('synth')
if duration is not None:
args.append(str(duration))
args += ['sine', str(frequence)]
if gain is not None:
args += ['gain', str(gain)]
return args
def noise_profile(*arg, **karg):
"""A helper function to execute the noise_profile_cmd."""
return cmd_utils.execute(noise_profile_cmd(*arg, **karg))
def noise_profile_cmd(input, output, channels=1, bits=16, rate=48000):
"""Gets the noise profile of the input audio.
@param input: The input audio.
@param output: The file where the output profile will be stored in.
@param channels: The number of channels.
@param bits: The number of bits of each sample.
@param rate: The sampling rate.
"""
args = [SOX_PATH]
args += _raw_format_args(channels, bits, rate)
args += [input, '-n', 'noiseprof', output]
return args
def noise_reduce(*args, **kargs):
"""A helper function to execute the noise_reduce_cmd."""
return cmd_utils.execute(noise_reduce_cmd(*args, **kargs))
def noise_reduce_cmd(
input, output, noise_profile, channels=1, bits=16, rate=48000):
"""Reduce noise in the input audio by the given noise profile.
@param input: The input audio file.
@param ouput: The output file in which the noise reduced audio is stored.
@param noise_profile: The noise profile.
@param channels: The number of channels.
@param bits: The number of bits of each sample.
@param rate: The sampling rate.
"""
args = [SOX_PATH]
format_args = _raw_format_args(channels, bits, rate)
args += format_args
args.append(input)
# Uses the same format for output.
args += format_args
args.append(output)
args.append('noisered')
args.append(noise_profile)
return args
def extract_channel_cmd(
input, output, channel_index, channels=2, bits=16, rate=48000):
"""Extract the specified channel data from the given input audio file.
@param input: The input audio file.
@param output: The output file to which the extracted channel is stored
@param channel_index: The index of the channel to be extracted.
Note: 1 for the first channel.
@param channels: The number of channels.
@param bits: The number of bits of each sample.
@param rate: The sampling rate.
"""
args = [SOX_PATH]
args += _raw_format_args(channels, bits, rate)
args.append(input)
args += ['-t', 'raw', output]
args += ['remix', str(channel_index)]
return args
def stat_cmd(input, channels=1, bits=16, rate=44100):
"""Get statistical information about the input audio data.
The statistics will be output to standard error.
@param input: The input audio file.
@param channels: The number of channels.
@param bits: The number of bits of each sample.
@param rate: The sampling rate.
"""
args = [SOX_PATH]
args += _raw_format_args(channels, bits, rate)
args += [input, '-n', 'stat']
return args
def get_stat(*args, **kargs):
"""A helper function to execute the stat_cmd.
It returns the statistical information (in text) read from the standard
error.
"""
p = cmd_utils.popen(stat_cmd(*args, **kargs), stderr=cmd_utils.PIPE)
#The output is read from the stderr instead of stdout
stat_output = p.stderr.read()
cmd_utils.wait_and_check_returncode(p)
return parse_stat_output(stat_output)
_SOX_STAT_ATTR_MAP = {
'Samples read': ('sameple_count', int),
'Length (seconds)': ('length', float),
'RMS amplitude': ('rms', float),
'Rough frequency': ('rough_frequency', float)}
_RE_STAT_LINE = re.compile('(.*):(.*)')
class _SOX_STAT:
def __str__(self):
return str(vars(self))
def _remove_redundant_spaces(value):
return ' '.join(value.split()).strip()
def parse_stat_output(stat_output):
"""A helper function to parses the stat_cmd's output to get a python object
for easy access to the statistics.
It returns a python object with the following attributes:
.sample_count: The number of the audio samples.
.length: The length of the audio (in seconds).
.rms: The RMS value of the audio.
.rough_frequency: The rough frequency of the audio (in Hz).
@param stat_output: The statistics ouput to be parsed.
"""
stat = _SOX_STAT()
for line in stat_output.splitlines():
match = _RE_STAT_LINE.match(line)
if not match:
continue
key, value = (_remove_redundant_spaces(x) for x in match.groups())
attr, convfun = _SOX_STAT_ATTR_MAP.get(key, (None, None))
if attr:
setattr(stat, attr, convfun(value))
if not all(hasattr(stat, x[0]) for x in _SOX_STAT_ATTR_MAP.values()):
logging.error('stat_output: %s', stat_output)
raise RuntimeError('missing entries: ' + str(stat))
return stat
def convert_raw_file(path_src, channels_src, bits_src, rate_src,
path_dst):
"""Converts a raw file to a new format.
@param path_src: The path to the source file.
@param channels_src: The channel number of the source file.
@param bits_src: The size of sample in bits of the source file.
@param rate_src: The sampling rate of the source file.
@param path_dst: The path to the destination file. The file name determines
the new file format.
"""
sox_cmd = [SOX_PATH]
sox_cmd += _raw_format_args(channels_src, bits_src, rate_src)
sox_cmd += [path_src]
sox_cmd += [path_dst]
cmd_utils.execute(sox_cmd)
def convert_format(path_src, channels_src, bits_src, rate_src,
path_dst, channels_dst, bits_dst, rate_dst,
volume_scale):
"""Converts a raw file to a new format.
@param path_src: The path to the source file.
@param channels_src: The channel number of the source file.
@param bits_src: The size of sample in bits of the source file.
@param rate_src: The sampling rate of the source file.
@param path_dst: The path to the destination file.
@param channels_dst: The channel number of the destination file.
@param bits_dst: The size of sample in bits of the destination file.
@param rate_dst: The sampling rate of the destination file.
@param volume_scale: A float for volume scale used in sox command.
E.g. 1.0 is the same. 0.5 to scale volume by
half. -1.0 to invert the data.
"""
sox_cmd = [SOX_PATH]
sox_cmd += _raw_format_args(channels_src, bits_src, rate_src)
sox_cmd += ['-v', '%f' % volume_scale]
sox_cmd += [path_src]
sox_cmd += _raw_format_args(channels_dst, bits_dst, rate_dst)
sox_cmd += [path_dst]
cmd_utils.execute(sox_cmd)
def lowpass_filter(path_src, channels_src, bits_src, rate_src,
path_dst, frequency):
"""Passes a raw file to a lowpass filter.
@param path_src: The path to the source file.
@param channels_src: The channel number of the source file.
@param bits_src: The size of sample in bits of the source file.
@param rate_src: The sampling rate of the source file.
@param path_dst: The path to the destination file.
@param frequency: A float for frequency used in sox command. The 3dB
frequency of the lowpass filter. Checks manual of sox
command for detail.
"""
sox_cmd = [SOX_PATH]
sox_cmd += _raw_format_args(channels_src, bits_src, rate_src)
sox_cmd += [path_src]
sox_cmd += _raw_format_args(channels_src, bits_src, rate_src)
sox_cmd += [path_dst]
sox_cmd += ['lowpass', '-2', str(frequency)]
cmd_utils.execute(sox_cmd)