def _fade(self, volume, duration):
start_volume = itunes.volume_get()
end_volume = normalize_volume(volume)
step_count = abs(end_volume - start_volume)
duration = float(duration)
if step_count == 0:
# no volume change
self.logger.debug(u'no fade: no volume change')
elif duration <= MIN_STEP_TIME:
# instant volume change
self.logger.debug(u'no fade: instant volume change')
itunes.volume_set(end_volume)
else:
# actual fade
# calculate fade steps
step_size = up_down = [-1,1][end_volume >= start_volume]
step_wait = duration/step_count
while step_wait < MIN_STEP_TIME:
# ensure minimumAllowed time between steps
step_size += up_down
step_count = int(abs((end_volume - start_volume)/step_size))
step_wait = duration/step_count
final_step = (start_volume + step_count * step_size != end_volume)
# calculate loop timing
loop_wait = step_wait
while loop_wait > MAX_LOOP_TIME:
# loop on multiple of step_wait
loop_wait = loop_wait / 2
# do the fade
self.stopped = False
self.logger.debug(u'start fade: v{}/{:.4f}s ({}/{:+}/{:.4f})'.format(end_volume,duration,step_count,step_size,step_wait))
time_start = time.time()
next_step = time_start + step_wait
volume = start_volume
count = 0
while not self.stopped:
loop_time = time.time()
if loop_time >= next_step:
volume += step_size
count += 1
itunes.volume_set(volume)
next_step += step_wait
if count == step_count:
break
time.sleep(max(0, loop_wait - (time.time() - loop_time)))
if not self.stopped:
if final_step:
volume = end_volume
itunes.volume_set(volume)
self.logger.debug(u'end fade: v{}/{:.4f}s ({}/{:+}/{:.4f})'.format(volume,time.time()-time_start,count,step_size,step_wait))
else:
self.logger.debug(u'stop fade: v{}/{:.4f}s ({}/{:+}/{:.4f})'.format(volume,time.time()-time_start,count,step_size,step_wait))
def _setVolume(self,value):
value = int(normalize_volume(value)/100.0 * itunes.volume_get())
self.logger.debug(u'set airplay "{}" volume: {}'.format(self.name,value))
itunes.airplay_device_volume_set(self.name, value)
def _volume_get(self):
value = itunes.volume_get()
self.logger.debug(u'get volume: {}'.format(value))
return value