class Meter(object):
class StopException(Exception):
pass
def __init__(self, segment_length=None):
"""
:param float segment_length: A float representing `AUDIO_SEGMENT_LENGTH`
"""
print("__init__")
global _soundmeter
_soundmeter = self # Register this object globally for use in signal handlers (see below)
self.output = BytesIO()
self.audio = pyaudio.PyAudio()
self.stream = self.audio.open(format=FORMAT, channels=CHANNELS, rate=RATE, input=True, frames_per_buffer=FRAMES_PER_BUFFER)
self.segment_length = segment_length
self.is_running = False
self._graceful = False # Graceful stop switch
self._data = {}
self.acc = Accumulator(-100,0)
self.points = 0
def record(self):
"""
Record PyAudio stream into StringIO output
This generator keeps stream open; the stream is closed in stop()
"""
while True:
frames = []
self.stream.start_stream()
for i in range(self.num_frames):
data = self.stream.read(FRAMES_PER_BUFFER)
frames.append(data)
self.output.seek(0)
w = wave.open(self.output, 'wb')
w.setnchannels(CHANNELS)
w.setsampwidth(self.audio.get_sample_size(FORMAT))
w.setframerate(RATE)
w.writeframes(b''.join(frames))
w.close()
yield
def start(self):
segment = self.segment_length or AUDIO_SEGMENT_LENGTH
self.num_frames = int(RATE / FRAMES_PER_BUFFER * segment)
try:
self.is_running = True
record = self.record()
while not self._graceful:
next(record) # Record stream `AUDIO_SEGMENT_LENGTH' long in the generator method 'record'
data = self.output.getvalue()
segment = pydub.AudioSegment(data)
rms = segment.rms
dbfs = segment.dBFS
self.meter(rms, dbfs)
self.is_running = False
self.stop()
except self.__class__.StopException:
self.is_running = False
self.stop()
def meter(self, rms, dbfs):
if not self._graceful:
if self.acc.n < ACCUMULATE:
self.acc.addValue(dbfs)
else:
if self.acc.mean() < -40:
self.points = self.points + 1
moteflash()
sys.stdout.write("\nAccumulation: min{:+8.3f}\tmax{:+8.3f}\tmean{:+8.3f}\tpoints{:4d}\n".format(self.acc.min_value, self.acc.max_value, self.acc.mean(), self.points))
self.acc = Accumulator(-100,0) # reset accumulator
mm = 128 + dbfs # motemeter value
sys.stdout.write("\r{:+08.3f}\t{:+08.3f}".format(dbfs,mm))
sys.stdout.flush()
motemeter(mm)
def graceful(self):
"""Graceful stop so that the while loop in start() will stop after the
current recording cycle"""
self._graceful = True
def stop(self):
"""Stop the stream and terminate PyAudio"""
if not self._graceful:
self._graceful = True
self.stream.stop_stream()
self.audio.terminate()
sys.stdout.write("\nPoints={0}\n".format(self.points))
mote.clear()
mote.show()
