def reduce_noise_and_get_rms(input_audio,
noise_file,
channels=1,
bits=16,
rate=48000):
"""Reduces noise in the input audio by the given noise file and then gets
the RMS values of all channels of the input audio.
@param input_audio: The input audio file to be analyzed.
@param noise_file: The noise file used to reduce noise in the input audio.
@param channels: The number of channels in the input audio.
@param bits: The number of bits of each audio sample.
@param rate: The sampling rate.
"""
with tempfile.NamedTemporaryFile() as reduced_file:
p1 = cmd_utils.popen(sox_utils.noise_profile_cmd(noise_file,
'-',
channels=channels,
bits=bits,
rate=rate),
stdout=subprocess.PIPE)
p2 = cmd_utils.popen(sox_utils.noise_reduce_cmd(input_audio,
reduced_file.name,
'-',
channels=channels,
bits=bits,
rate=rate),
stdin=p1.stdout)
cmd_utils.wait_and_check_returncode(p1, p2)
return get_rms(reduced_file.name, channels, bits, rate)
def get_channel_sox_stat(
input_audio, channel_index, channels=2, bits=16, rate=48000):
"""Gets the sox stat info of the selected channel in the input audio file.
@param input_audio: The input audio file to be analyzed.
@param channel_index: The index of the channel to be analyzed.
(1 for the first channel).
@param channels: The number of channels in the input audio.
@param bits: The number of bits of each audio sample.
@param rate: The sampling rate.
"""
if channel_index <= 0 or channel_index > channels:
raise ValueError('incorrect channel_indexi: %d' % channel_index)
if channels == 1:
return sox_utils.get_stat(
input_audio, channels=channels, bits=bits, rate=rate)
p1 = cmd_utils.popen(
sox_utils.extract_channel_cmd(
input_audio, '-', channel_index,
channels=channels, bits=bits, rate=rate),
stdout=subprocess.PIPE)
p2 = cmd_utils.popen(
sox_utils.stat_cmd('-', channels=1, bits=bits, rate=rate),
stdin=p1.stdout, stderr=subprocess.PIPE)
stat_output = p2.stderr.read()
cmd_utils.wait_and_check_returncode(p1, p2)
return sox_utils.parse_stat_output(stat_output)
def run_once(self):
"""Entry point of this test."""
self.chrome.browser.platform.SetHTTPServerDirectories(self.bindir)
video_url = self.chrome.browser.platform.http_server.UrlOf(
os.path.join(self.bindir, 'youtube.html'))
logging.info('Playing back youtube media file %s.', video_url)
noise_file = os.path.join(self.resultsdir, "noise.wav")
recorded_file = os.path.join(self.resultsdir, "recorded.wav")
loopback_file = os.path.join(self.resultsdir, "loopback.wav")
# Record a sample of "silence" to use as a noise profile.
cras_utils.capture(noise_file, duration=3)
# Play a video and record the audio output
self.play_video(self.chrome.browser.tabs[0], video_url)
p1 = cmd_utils.popen(
cras_utils.capture_cmd(recorded_file, duration=TEST_DURATION))
p2 = cmd_utils.popen(
cras_utils.loopback_cmd(loopback_file, duration=TEST_DURATION))
cmd_utils.wait_and_check_returncode(p1, p2)
# See if we recorded something
loopback_stats = [
audio_helper.get_channel_sox_stat(loopback_file, i) for i in (1, 2)
]
logging.info('loopback stats: %s', [str(s) for s in loopback_stats])
rms_value = audio_helper.reduce_noise_and_get_rms(
recorded_file, noise_file)[0]
self.write_perf_keyval({'rms_value': rms_value})
def rms_test(self, tab, media_file, noiseprof_file, test_duration):
logging.info('rms test on media file %s.', media_file)
recorded_file = os.path.join(self.resultsdir, 'recorded.wav')
loopback_file = os.path.join(self.resultsdir, 'loopback.wav')
# Plays the media_file in the browser.
self.play_media(tab, media_file)
# Record the audio output and also the CRAS loopback output.
p1 = cmd_utils.popen(
cras_utils.capture_cmd(recorded_file, duration=test_duration))
p2 = cmd_utils.popen(
cras_utils.loopback_cmd(loopback_file, duration=test_duration))
cmd_utils.wait_and_check_returncode(p1, p2)
# See if we recorded something.
# We captured two channels of audio in the CRAS loopback.
# The RMS values are for debugging only.
loopback_stats = [
audio_helper.get_channel_sox_stat(loopback_file, i) for i in (1, 2)
]
logging.info('loopback stats: %s', [str(s) for s in loopback_stats])
reduced_file = tempfile.NamedTemporaryFile()
sox_utils.noise_reduce(recorded_file, reduced_file.name,
noiseprof_file)
rms = audio_helper.get_rms(reduced_file.name)[0]
self._rms_values['%s_rms_value' % media_file.replace('.', '_')] = rms
# Make sure the audio can be played to the end.
self.wait_player_end(tab)
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)
def playback(blocking=True, *args, **kargs):
"""A helper function to execute the playback_cmd.
@param blocking: Blocks this call until playback finishes.
@param args: args passed to playback_cmd.
@param kargs: kargs passed to playback_cmd.
@returns: The process running the playback command. Note that if the
blocking parameter is true, this will return a finished process.
"""
process = cmd_utils.popen(playback_cmd(*args, **kargs))
if blocking:
cmd_utils.wait_and_check_returncode(process)
return process
