--- a/test2.py +++ b/test2.py @@ -1,1 +1,121 @@ +from os.path import exists +from array import array +from struct import unpack, pack +import pyaudio +import wave + +THRESHOLD = 500 +CHUNK_SIZE = 1024 +FORMAT = pyaudio.paInt16 +RATE = 44100 + +def is_silent(L): + "Returns `True` if below the 'silent' threshold" + return max(L) < THRESHOLD + +def normalize(L): + "Average the volume out" + MAXIMUM = 16384 + times = float(MAXIMUM)/max(abs(i) for i in L) + + LRtn = array('h') + for i in L: + LRtn.append(int(i*times)) + return LRtn + +def trim(L): + "Trim the blank spots at the start and end" + def _trim(L): + snd_started = False + LRtn = array('h') + + for i in L: + if not snd_started and abs(i)>THRESHOLD: + snd_started = True + LRtn.append(i) + + elif snd_started: + LRtn.append(i) + return LRtn + + # Trim to the left + L = _trim(L) + + # Trim to the right + L.reverse() + L = _trim(L) + L.reverse() + return L + +def add_silence(L, seconds): + "Add silence to the start and end of `L` of length `seconds` (float)" + LRtn = array('h', [0 for i in xrange(int(seconds*RATE))]) + LRtn.extend(L) + LRtn.extend([0 for i in xrange(int(seconds*RATE))]) + return LRtn + +def record(): + """ + Record a word or words from the microphone and + return the data as an array of signed shorts. + + Normalizes the audio, trims silence from the + start and end, and pads with 0.5 seconds of + blank sound to make sure VLC et al can play + it without getting chopped off. + """ + p = pyaudio.PyAudio() + stream = p.open(format=FORMAT, channels=2, rate=RATE, + input=True, + frames_per_buffer=CHUNK_SIZE) + + num_silent = 0 + snd_started = False + + LRtn = array('h') + + while 1: + data = stream.read(CHUNK_SIZE) + L = unpack('<' + ('h'*(len(data)/2)), data) # little endian, signed short + L = array('h', L) + LRtn.extend(L) + + silent = is_silent(L) + #print silent, num_silent, L[:10] + + if silent and snd_started: + num_silent += 1 + elif not silent and not snd_started: + snd_started = True + + if snd_started and num_silent > 30: + break + + sample_width = p.get_sample_size(FORMAT) + stream.stop_stream() + stream.close() + p.terminate() + + LRtn = normalize(LRtn) + LRtn = trim(LRtn) + LRtn = add_silence(LRtn, 0.5) + return sample_width, LRtn + +def record_to_file(path): + "Records from the microphone and outputs the resulting data to `path`" + sample_width, data = record() + data = pack('<' + ('h'*len(data)), *data) + + wf = wave.open(path, 'wb') + wf.setnchannels(2) + wf.setsampwidth(sample_width) + wf.setframerate(RATE) + wf.writeframes(data) + wf.close() + +if __name__ == '__main__': + print("please speak a word into the microphone") + record_to_file('demo.wav') + print("done - result written to demo.wav") +