#! /usr/bin/env python import sysfrom aubio import source, sink, pvoc if __name__ == '__main__':    if len(sys.argv) < 2:        print('usage: %s <inputfile> <outputfile>' % sys.argv[0])        sys.exit(1)    samplerate = 44100    f = source(sys.argv[1], samplerate, 256)    g = sink(sys.argv[2], samplerate)    total_frames, read = 0, 256     win_s = 512                          # fft size    hop_s = win_s // 2                   # hop size    pv = pvoc(win_s, hop_s)              # phase vocoder     while read:        samples, read = f()        spectrum = pv(samples)           # compute spectrum        #spectrum.norm *= .8             # reduce amplitude a bit        spectrum.phas[:] = 0.            # zero phase        new_samples = pv.rdo(spectrum)   # compute modified samples        g(new_samples, read)             # write to output        total_frames += read     format_str = "read {:d} samples from {:s}, written to {:s}"    print(format_str.format(total_frames, f.uri, g.uri))