Demo/sgi/al/cmpaf.py

   1 # Compare different audio compression schemes.
   2 #
   3 # This copies mono audio data from the input port to the output port,
   4 # and puts up a window with 4 toggle buttons:
   5 #
   6 # uLAW       : convert the data to uLAW and back
   7 # ADPCM      : convert the data to ADPCM and back
   8 # Difference : make only the difference between the converted and the
   9 #              original data audible
  10 # Exit       : quit from the program
  11
  12 import fl
  13 import FL
  14 import flp
  15 import al
  16 import AL
  17 import audioop
  18 import sys
  19
  20 class Cmpaf():
  21         def init(self):
  22                 parsetree = flp.parse_form('cmpaf_form','form')
  23                 flp.create_full_form(self, parsetree)
  24                 c = al.newconfig()
  25                 c.setchannels(AL.MONO)
  26                 c.setqueuesize(1800)
  27                 self.iport = al.openport('cmpaf','r', c)
  28                 self.oport = al.openport('cmpaf','w', c)
  29                 self.do_adpcm = self.do_ulaw = self.do_diff = 0
  30                 self.acstate = None
  31                 self.form.show_form(FL.PLACE_SIZE, 1, 'compare audio formats')
  32                 return self
  33
  34         def run(self):
  35                 while 1:
  36                         olddata = data = self.iport.readsamps(600)
  37                         if self.do_ulaw:
  38                                 data = audioop.lin2ulaw(data, 2)
  39                                 data = audioop.ulaw2lin(data, 2)
  40                         if self.do_adpcm:
  41                                 data, nacstate = audioop.lin2adpcm(data, 2, \
  42                                           self.acstate)
  43                                 data, dummy = audioop.adpcm2lin(data, 2, \
  44                                           self.acstate)
  45                                 self.acstate = nacstate
  46                         if self.do_diff:
  47                                 olddata = audioop.mul(olddata, 2, -1)
  48                                 data = audioop.add(olddata, data, 2)
  49                         self.oport.writesamps(data)
  50                         fl.check_forms()
  51
  52         def cb_exit(self, *args):
  53                 sys.exit(0)
  54
  55         def cb_adpcm(self, obj, val):
  56                 self.do_adpcm = obj.get_button()
  57
  58         def cb_ulaw(self, obj, val):
  59                 self.do_ulaw = obj.get_button()
  60
  61         def cb_diff(self, obj, val):
  62                 self.do_diff = obj.get_button()
  63
  64 cmpaf = Cmpaf().init()
  65 cmpaf.run()