1# Copyright (c) 2013 The Chromium Authors. All rights reserved.
2# Use of this source code is governed by a BSD-style license that can be
3# found in the LICENSE file.
4
5import logging
6import re
7import subprocess
8
9from autotest_lib.client.cros.audio import cmd_utils
10
11SOX_PATH = 'sox'
12
13def _raw_format_args(channels, bits, rate):
14    """Gets raw format args used in sox.
15
16    @param channels: Number of channels.
17    @param bits: Bit length for a sample.
18    @param rate: Sampling rate.
19
20    @returns: A list of args.
21
22    """
23    args = ['-t', 'raw', '-e', 'signed']
24    args += _format_args(channels, bits, rate)
25    return args
26
27
28def _format_args(channels, bits, rate):
29    """Gets format args used in sox.
30
31    @param channels: Number of channels.
32    @param bits: Bit length for a sample.
33    @param rate: Sampling rate.
34
35    @returns: A list of args.
36
37    """
38    return ['-c', str(channels), '-b', str(bits), '-r', str(rate)]
39
40
41def generate_sine_tone_cmd(
42        filename, channels=2, bits=16, rate=48000, duration=None, frequencies=440,
43        gain=None, vol=None, raw=True):
44    """Gets a command to generate sine tones at specified ferquencies.
45
46    @param filename: The name of the file to store the sine wave in.
47    @param channels: The number of channels.
48    @param bits: The number of bits of each sample.
49    @param rate: The sampling rate.
50    @param duration: The length of the generated sine tone (in seconds).
51    @param frequencies: The frequencies of the sine wave. Pass a number or a
52                        list to specify frequency for each channel.
53    @param gain: The gain (in db).
54    @param vol: A float for volume scale used in sox command.
55                         E.g. 1.0 is the same. 0.5 to scale volume by
56                         half. -1.0 to invert the data.
57    @param raw: True to use raw data format. False to use what filename specifies.
58
59    """
60    args = [SOX_PATH, '-n']
61    if raw:
62        args += _raw_format_args(channels, bits, rate)
63    else:
64        args += _format_args(channels, bits, rate)
65    args.append(filename)
66    args.append('synth')
67    if duration is not None:
68        args.append(str(duration))
69    if not isinstance(frequencies, list):
70        frequencies = [frequencies]
71    for freq in frequencies:
72        args += ['sine', str(freq)]
73    if gain is not None:
74        args += ['gain', str(gain)]
75    if vol is not None:
76        args += ['vol', str(vol)]
77    return args
78
79
80def noise_profile(*args, **kwargs):
81    """A helper function to execute the noise_profile_cmd."""
82    return cmd_utils.execute(noise_profile_cmd(*args, **kwargs))
83
84
85def noise_profile_cmd(input, output, channels=1, bits=16, rate=48000):
86    """Gets the noise profile of the input audio.
87
88    @param input: The input audio.
89    @param output: The file where the output profile will be stored in.
90    @param channels: The number of channels.
91    @param bits: The number of bits of each sample.
92    @param rate: The sampling rate.
93    """
94    args = [SOX_PATH]
95    args += _raw_format_args(channels, bits, rate)
96    args += [input, '-n', 'noiseprof', output]
97    return args
98
99
100def noise_reduce(*args, **kwargs):
101    """A helper function to execute the noise_reduce_cmd."""
102    return cmd_utils.execute(noise_reduce_cmd(*args, **kwargs))
103
104
105def noise_reduce_cmd(
106        input, output, noise_profile, channels=1, bits=16, rate=48000):
107    """Reduce noise in the input audio by the given noise profile.
108
109    @param input: The input audio file.
110    @param output: The output file in which the noise reduced audio is stored.
111    @param noise_profile: The noise profile.
112    @param channels: The number of channels.
113    @param bits: The number of bits of each sample.
114    @param rate: The sampling rate.
115    """
116    args = [SOX_PATH]
117    format_args = _raw_format_args(channels, bits, rate)
118    args += format_args
119    args.append(input)
120    # Uses the same format for output.
121    args += format_args
122    args.append(output)
123    args.append('noisered')
124    args.append(noise_profile)
125    return args
126
127
128def extract_channel_cmd(
129        input, output, channel_index, channels=2, bits=16, rate=48000):
130    """Extract the specified channel data from the given input audio file.
131
132    @param input: The input audio file.
133    @param output: The output file to which the extracted channel is stored
134    @param channel_index: The index of the channel to be extracted.
135                          Note: 1 for the first channel.
136    @param channels: The number of channels.
137    @param bits: The number of bits of each sample.
138    @param rate: The sampling rate.
139    """
140    args = [SOX_PATH]
141    args += _raw_format_args(channels, bits, rate)
142    args.append(input)
143    args += ['-t', 'raw', output]
144    args += ['remix', str(channel_index)]
145    return args
146
147
148def stat_cmd(input, channels=1, bits=16, rate=44100):
149    """Get statistical information about the input audio data.
150
151    The statistics will be output to standard error.
152
153    @param input: The input audio file.
154    @param channels: The number of channels.
155    @param bits: The number of bits of each sample.
156    @param rate: The sampling rate.
157    """
158    args = [SOX_PATH]
159    args += _raw_format_args(channels, bits, rate)
160    args += [input, '-n', 'stat']
161    return args
162
163
164def get_stat(*args, **kargs):
165    """A helper function to execute the stat_cmd.
166
167    It returns the statistical information (in text) read from the standard
168    error.
169    """
170    p = cmd_utils.popen(stat_cmd(*args, **kargs), stderr=subprocess.PIPE)
171
172    #The output is read from the stderr instead of stdout
173    stat_output = p.stderr.read()
174    cmd_utils.wait_and_check_returncode(p)
175    return parse_stat_output(stat_output)
176
177
178_SOX_STAT_ATTR_MAP = {
179        'Samples read': ('sameple_count', int),
180        'Length (seconds)': ('length', float),
181        'RMS amplitude': ('rms', float),
182        'Rough frequency': ('rough_frequency', float)}
183
184_RE_STAT_LINE = re.compile('(.*):(.*)')
185
186class _SOX_STAT:
187    def __str__(self):
188        return str(vars(self))
189
190
191def _remove_redundant_spaces(value):
192    return ' '.join(value.split()).strip()
193
194
195def parse_stat_output(stat_output):
196    """A helper function to parses the stat_cmd's output to get a python object
197    for easy access to the statistics.
198
199    It returns a python object with the following attributes:
200      .sample_count: The number of the audio samples.
201      .length: The length of the audio (in seconds).
202      .rms: The RMS value of the audio.
203      .rough_frequency: The rough frequency of the audio (in Hz).
204
205    @param stat_output: The statistics ouput to be parsed.
206    """
207    stat = _SOX_STAT()
208
209    for line in stat_output.splitlines():
210        match = _RE_STAT_LINE.match(line)
211        if not match:
212            continue
213        key, value = (_remove_redundant_spaces(x) for x in match.groups())
214        attr, convfun = _SOX_STAT_ATTR_MAP.get(key, (None, None))
215        if attr:
216            setattr(stat, attr, convfun(value))
217
218    if not all(hasattr(stat, x[0]) for x in _SOX_STAT_ATTR_MAP.values()):
219        logging.error('stat_output: %s', stat_output)
220        raise RuntimeError('missing entries: ' + str(stat))
221
222    return stat
223
224
225def convert_raw_file(path_src, channels_src, bits_src, rate_src,
226                     path_dst):
227    """Converts a raw file to a new format.
228
229    @param path_src: The path to the source file.
230    @param channels_src: The channel number of the source file.
231    @param bits_src: The size of sample in bits of the source file.
232    @param rate_src: The sampling rate of the source file.
233    @param path_dst: The path to the destination file. The file name determines
234                     the new file format.
235
236    """
237    sox_cmd = [SOX_PATH]
238    sox_cmd += _raw_format_args(channels_src, bits_src, rate_src)
239    sox_cmd += [path_src]
240    sox_cmd += [path_dst]
241    cmd_utils.execute(sox_cmd)
242
243
244def convert_format(path_src, channels_src, bits_src, rate_src,
245                   path_dst, channels_dst, bits_dst, rate_dst,
246                   volume_scale, use_src_header=False, use_dst_header=False):
247    """Converts a raw file to a new format.
248
249    @param path_src: The path to the source file.
250    @param channels_src: The channel number of the source file.
251    @param bits_src: The size of sample in bits of the source file.
252    @param rate_src: The sampling rate of the source file.
253    @param path_dst: The path to the destination file.
254    @param channels_dst: The channel number of the destination file.
255    @param bits_dst: The size of sample in bits of the destination file.
256    @param rate_dst: The sampling rate of the destination file.
257    @param volume_scale: A float for volume scale used in sox command.
258                         E.g. 1.0 is the same. 0.5 to scale volume by
259                         half. -1.0 to invert the data.
260    @param use_src_header: True to use header from source file and skip
261                           specifying channel, sample format, and rate for
262                           source. False otherwise.
263    @param use_dst_header: True to use header for dst file. False to treat
264                           dst file as a raw file.
265
266    """
267    sox_cmd = [SOX_PATH]
268
269    if not use_src_header:
270        sox_cmd += _raw_format_args(channels_src, bits_src, rate_src)
271    sox_cmd += ['-v', '%f' % volume_scale]
272    sox_cmd += [path_src]
273
274    if not use_dst_header:
275        sox_cmd += _raw_format_args(channels_dst, bits_dst, rate_dst)
276    else:
277        sox_cmd += _format_args(channels_dst, bits_dst, rate_dst)
278    sox_cmd += [path_dst]
279
280    cmd_utils.execute(sox_cmd)
281
282
283def lowpass_filter(path_src, channels_src, bits_src, rate_src,
284                   path_dst, frequency):
285    """Passes a raw file to a lowpass filter.
286
287    @param path_src: The path to the source file.
288    @param channels_src: The channel number of the source file.
289    @param bits_src: The size of sample in bits of the source file.
290    @param rate_src: The sampling rate of the source file.
291    @param path_dst: The path to the destination file.
292    @param frequency: A float for frequency used in sox command. The 3dB
293                      frequency of the lowpass filter. Checks manual of sox
294                      command for detail.
295
296    """
297    sox_cmd = [SOX_PATH]
298    sox_cmd += _raw_format_args(channels_src, bits_src, rate_src)
299    sox_cmd += [path_src]
300    sox_cmd += _raw_format_args(channels_src, bits_src, rate_src)
301    sox_cmd += [path_dst]
302    sox_cmd += ['lowpass', '-2', str(frequency)]
303    cmd_utils.execute(sox_cmd)
304
305
306def trim_silence_from_wav_file(path_src, path_dst, new_duration, volume=1,
307                               duration_threshold=0):
308    """Trim silence from beginning of a file.
309
310    Trim silence from beginning of file, and trim remaining audio to
311    new_duration seconds in length.
312
313    @param path_src: The path to the source file.
314    @oaram path_dst: The path to the destination file.
315    @param new_duration: The new duration of the destination file in seconds.
316    @param volume: [Optional] A float indicating the volume in percent, below
317                   which sox will consider silence, defaults to 1 (1%).
318    @param duration_threshold: [Optional] A float of the duration in seconds of
319                               sound above volume parameter required to consider
320                               end of silence. Defaults to 0 (0 seconds).
321    """
322    mins, secs = divmod(new_duration, 60)
323    hrs, mins = divmod(mins, 60)
324    length_str = '{:d}:{:02d}:{:.3f}'.format(int(hrs), int(mins), float(secs))
325
326    sox_cmd = [SOX_PATH]
327    sox_cmd += ['-G', path_src, path_dst]
328    sox_cmd += ['silence', '1', str(duration_threshold), '{}%'.format(volume)]
329    sox_cmd += ['trim', '0', length_str]
330
331    cmd_utils.execute(sox_cmd)
332
333
334def get_file_length(file_path, channels, bits, rate):
335    """Get the length in seconds of an audio file.
336
337    @param file_path: Path to audio file.
338    @param channels: The number of channels.
339    @param bits: The number of bits of each sample.
340    @param rate: The sampling rate.
341
342    @returns: float length in seconds
343    """
344    return get_stat(file_path, channels, bits, rate).length
345