# Compare different audio compression schemes.
#
# This copies mono audio data from the input port to the output port,
# and puts up a window with 4 toggle buttons:
#
# uLAW : convert the data to uLAW and back
# ADPCM : convert the data to ADPCM and back
# Difference : make only the difference between the converted and the
# original data audible
# Exit : quit from the program
import fl
import FL
import flp
import al
import AL
import audioop
import sys
class Cmpaf:
def __init__(self):
parsetree = flp.parse_form('cmpaf_form','form')
flp.create_full_form(self, parsetree)
c = al.newconfig()
c.setchannels(AL.MONO)
c.setqueuesize(1800)
self.iport = al.openport('cmpaf','r', c)
self.oport = al.openport('cmpaf','w', c)
self.do_adpcm = self.do_ulaw = self.do_diff = 0
self.acstate = None
self.form.show_form(FL.PLACE_SIZE, 1, 'compare audio formats')
def run(self):
while 1:
olddata = data = self.iport.readsamps(600)
if self.do_ulaw:
data = audioop.lin2ulaw(data, 2)
data = audioop.ulaw2lin(data, 2)
if self.do_adpcm:
data, nacstate = audioop.lin2adpcm(data, 2, \
self.acstate)
data, dummy = audioop.adpcm2lin(data, 2, \
self.acstate)
self.acstate = nacstate
if self.do_diff:
olddata = audioop.mul(olddata, 2, -1)
data = audioop.add(olddata, data, 2)
self.oport.writesamps(data)
fl.check_forms()
def cb_exit(self, *args):
sys.exit(0)
def cb_adpcm(self, obj, val):
self.do_adpcm = obj.get_button()
def cb_ulaw(self, obj, val):
self.do_ulaw = obj.get_button()
def cb_diff(self, obj, val):
self.do_diff = obj.get_button()
cmpaf = Cmpaf()
cmpaf.run()
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