ref: 89bc6f4938d3c1e41e351d7cd8314ed3fb3cd433
dir: /python/demos/demo_alsa.py/
#! /usr/bin/env python import alsaaudio import numpy as np import aubio # constants samplerate = 44100 win_s = 2048 hop_s = win_s // 2 framesize = hop_s # set up audio input recorder = alsaaudio.PCM(type=alsaaudio.PCM_CAPTURE) recorder.setperiodsize(framesize) recorder.setrate(samplerate) recorder.setformat(alsaaudio.PCM_FORMAT_FLOAT_LE) recorder.setchannels(1) # create aubio pitch detection (first argument is method, "default" is # "yinfft", can also be "yin", "mcomb", fcomb", "schmitt"). pitcher = aubio.pitch("default", win_s, hop_s, samplerate) # set output unit (can be 'midi', 'cent', 'Hz', ...) pitcher.set_unit("Hz") # ignore frames under this level (dB) pitcher.set_silence(-40) print("Starting to listen, press Ctrl+C to stop") # main loop while True: try: # read data from audio input _, data = recorder.read() # convert data to aubio float samples samples = np.fromstring(data, dtype=aubio.float_type) # pitch of current frame freq = pitcher(samples)[0] # compute energy of current block energy = np.sum(samples**2)/len(samples) # do something with the results print("{:10.4f} {:10.4f}".format(freq,energy)) except KeyboardInterrupt: print("Ctrl+C pressed, exiting") break