run_pklt.py 文件源码

def check_onset(audio):
        # Determine if there is an 'early' onset
        b_lpf, a_lpf = signal.butter(1, 200/44100.0, 'low')
        sim = numpy.square(audio)
        audio_lpf   = signal.filtfilt(b_lpf,a_lpf,sim)
        thres = 0.015

        invert = 0
        found = 0
        for i in xrange(len(audio)):
                if ((audio_lpf[i] > thres) and not found):
                        if (i < 4000):
                                print "Detected onset for ",fil," at time ",i/44.1," msecs "
                                found = 1
                                invert = 1
        return invert