python/demos/demo_slicing.py

   1 #! /usr/bin/env python
   2
   3 import sys
   4 import os.path
   5 from aubio import source, sink
   6
   7 if __name__ == '__main__':
   8     if len(sys.argv) < 3:
   9         print('usage: %s <inputfile> <duration>' % sys.argv[0])
  10         sys.exit(1)
  11     source_file = sys.argv[1]
  12     duration = float(sys.argv[2])
  13     source_base_name, source_ext = os.path.splitext(os.path.basename(source_file))
  14
  15     hopsize = 256
  16     slice_n, total_frames_written, read = 0, 0, hopsize
  17
  18     def new_sink_name(source_base_name, slice_n, duration = duration):
  19         return source_base_name + '_%02.3f' % (slice_n*duration) + '.wav'
  20
  21     f = source(source_file, 0, hopsize)
  22     samplerate = f.samplerate
  23     g = sink(new_sink_name(source_base_name, slice_n), samplerate)
  24
  25     #print "new slice:", slice_n, 0, "+", 0, "=", 0
  26     while read == hopsize:
  27         vec, read = f()
  28         start_of_next_region = int(duration * samplerate * (slice_n + 1))
  29         remaining = start_of_next_region - total_frames_written
  30         # number of samples remaining is less than what we got
  31         if remaining <= read:
  32             # write remaining samples from current region
  33             g(vec[0:remaining], remaining)
  34             # close this file
  35             del g
  36             #print "new slice", slice_n, total_frames_written, "+", remaining, "=", start_of_next_region
  37             slice_n += 1
  38             # create a new file for the new region
  39             g = sink(new_sink_name(source_base_name, slice_n), samplerate)
  40             # write the remaining samples in the new file
  41             g(vec[remaining:read], read - remaining)
  42         else:
  43             g(vec[0:read], read)
  44         total_frames_written += read
  45     total_duration = total_frames_written / float(samplerate)
  46     slice_n += 1
  47     outstr = 'created %(slice_n)s slices from %(source_base_name)s%(source_ext)s' % locals()
  48     outstr += ' (total duration %(total_duration).2fs)' % locals()
  49     print(outstr)
  50     # close source and sink files
  51     del f, g