#! /usr/bin/env python import sysfrom aubio import tempo, source win_s = 512                 # fft sizehop_s = win_s // 2          # hop size if len(sys.argv) < 2:    print("Usage: %s <filename> [samplerate]" % sys.argv[0])    sys.exit(1) filename = sys.argv[1] samplerate = 0if len( sys.argv ) > 2: samplerate = int(sys.argv[2]) s = source(filename, samplerate, hop_s)samplerate = s.samplerateo = tempo("default", win_s, hop_s, samplerate) # tempo detection delay, in samples# default to 4 blocks delay to catch up withdelay = 4. * hop_s # list of beats, in samplesbeats = [] # total number of frames readtotal_frames = 0while True:    samples, read = s()    is_beat = o(samples)    if is_beat:        this_beat = o.get_last_s()        beats.append(this_beat)    total_frames += read    if read < hop_s: break if len(beats) > 1:    # do plotting    from numpy import mean, median, diff    import matplotlib.pyplot as plt    bpms = 60./ diff(beats)    print('mean period: %.2fbpm, median: %.2fbpm' % (mean(bpms), median(bpms)))    print('plotting %s' % filename)    plt1 = plt.axes([0.1, 0.75, 0.8, 0.19])    plt2 = plt.axes([0.1, 0.1, 0.8, 0.65], sharex = plt1)    plt.rc('lines',linewidth='.8')    for stamp in beats: plt1.plot([stamp, stamp], [-1., 1.], '-r')    plt1.axis(xmin = 0., xmax = total_frames / float(samplerate) )    plt1.xaxis.set_visible(False)    plt1.yaxis.set_visible(False)     # plot actual periods    plt2.plot(beats[1:], bpms, '-', label = 'raw')     # plot moving median of 5 last periods    median_win_s = 5    bpms_median = [ median(bpms[i:i + median_win_s:1]) for i in range(len(bpms) - median_win_s ) ]    plt2.plot(beats[median_win_s+1:], bpms_median, '-', label = 'median of %d' % median_win_s)    # plot moving median of 10 last periods    median_win_s = 20    bpms_median = [ median(bpms[i:i + median_win_s:1]) for i in range(len(bpms) - median_win_s ) ]    plt2.plot(beats[median_win_s+1:], bpms_median, '-', label = 'median of %d' % median_win_s)     plt2.axis(ymin = min(bpms), ymax = max(bpms))    #plt2.axis(ymin = 40, ymax = 240)    plt.xlabel('time (mm:ss)')    plt.ylabel('beats per minute (bpm)')    plt2.set_xticklabels([ "%02d:%02d" % (t/60, t%60) for t in plt2.get_xticks()[:-1]], rotation = 50)     #plt.savefig('/tmp/t.png', dpi=200)    plt2.legend()    plt.show() else:    print('mean period: %.2fbpm, median: %.2fbpm' % (0, 0))    print('plotting %s' % filename)