#! /usr/bin/env python import sysfrom aubio import sourcefrom numpy import zeros, hstack def get_waveform_plot(filename, samplerate = 0, block_size = 4096, ax = None, downsample = 2**4):    import matplotlib.pyplot as plt    if not ax:        fig = plt.figure()        ax = fig.add_subplot(111)    hop_s = block_size     allsamples_max = zeros(0,)    downsample = downsample  # to plot n samples / hop_s     a = source(filename, samplerate, hop_s)            # source file    if samplerate == 0: samplerate = a.samplerate     total_frames = 0    while True:        samples, read = a()        # keep some data to plot it later        new_maxes = (abs(samples.reshape(hop_s//downsample, downsample))).max(axis=0)        allsamples_max = hstack([allsamples_max, new_maxes])        total_frames += read        if read < hop_s: break    allsamples_max = (allsamples_max > 0) * allsamples_max    allsamples_max_times = [ ( float (t) / downsample ) * hop_s for t in range(len(allsamples_max)) ]     ax.plot(allsamples_max_times,  allsamples_max, '-b')    ax.plot(allsamples_max_times, -allsamples_max, '-b')    ax.axis(xmin = allsamples_max_times[0], xmax = allsamples_max_times[-1])     set_xlabels_sample2time(ax, allsamples_max_times[-1], samplerate)    return ax def set_xlabels_sample2time(ax, latest_sample, samplerate):    ax.axis(xmin = 0, xmax = latest_sample)    if latest_sample / float(samplerate) > 60:        ax.set_xlabel('time (mm:ss)')        ax.set_xticklabels([ "%02d:%02d" % (t/float(samplerate)/60, (t/float(samplerate))%60) for t in ax.get_xticks()[:-1]], rotation = 50)    else:        ax.set_xlabel('time (ss.mm)')        ax.set_xticklabels([ "%02d.%02d" % (t/float(samplerate), 100*((t/float(samplerate))%1) ) for t in ax.get_xticks()[:-1]], rotation = 50)  if __name__ == '__main__':    import matplotlib.pyplot as plt    if len(sys.argv) < 2:        print("Usage: %s <filename>" % sys.argv[0])    else:        for soundfile in sys.argv[1:]:            get_waveform_plot(soundfile)            # display graph            plt.show()