Mac/Lib/Audio_mac.py

QSIZE = 100000
error='Audio_mac.error'

class Play_Audio_mac:

	def __init__(self, qsize=QSIZE):
		self._chan = None
		self._qsize = qsize
		self._outrate = 22254
		self._sampwidth = 1
		self._nchannels = 1
		self._gc = []
		self._usercallback = None

	def __del__(self):
		self.stop()
		self._usercallback = None

	def wait(self):
		import time
		while self.getfilled():
			time.sleep(0.1)
		self._chan = None
		self._gc = []

	def stop(self, quietNow = 1):
		##chan = self._chan
		self._chan = None
		##chan.SndDisposeChannel(1)
		self._gc = []

	def setoutrate(self, outrate):
		self._outrate = outrate

	def setsampwidth(self, sampwidth):
		self._sampwidth = sampwidth

	def setnchannels(self, nchannels):
		self._nchannels = nchannels

	def writeframes(self, data):
		import time
		from Carbon.Sound import bufferCmd, callBackCmd, extSH
		import struct
		import MacOS
		if not self._chan:
			from Carbon import Snd
			self._chan = Snd.SndNewChannel(5, 0, self._callback)
		nframes = len(data) / self._nchannels / self._sampwidth
		if len(data) != nframes * self._nchannels * self._sampwidth:
			raise error, 'data is not a whole number of frames'
		while self._gc and \
			  self.getfilled() + nframes > \
				self._qsize / self._nchannels / self._sampwidth:
			time.sleep(0.1)
		if self._sampwidth == 1:
			import audioop
			data = audioop.add(data, '\x80'*len(data), 1)
		h1 = struct.pack('llHhllbbl',
			id(data)+MacOS.string_id_to_buffer,
			self._nchannels,
			self._outrate, 0,
			0,
			0,
			extSH,
			60,
			nframes)
		h2 = 22*'\0'
		h3 = struct.pack('hhlll',
			self._sampwidth*8,
			0,
			0,
			0,
			0)
		header = h1+h2+h3
		self._gc.append((header, data))
		self._chan.SndDoCommand((bufferCmd, 0, header), 0)
		self._chan.SndDoCommand((callBackCmd, 0, 0), 0)

	def _callback(self, *args):
		del self._gc[0]
		if self._usercallback:
			self._usercallback()
			
	def setcallback(self, callback):
		self._usercallback = callback

	def getfilled(self):
		filled = 0
		for header, data in self._gc:
			filled = filled + len(data)
		return filled / self._nchannels / self._sampwidth

	def getfillable(self):
		return (self._qsize / self._nchannels / self._sampwidth) - self.getfilled()

	def ulaw2lin(self, data):
		import audioop
		return audioop.ulaw2lin(data, 2)

def test():
	import aifc
	import macfs
	fss, ok = macfs.PromptGetFile("Select an AIFF soundfile", "AIFF")
	if not ok: return
	fn = fss.as_pathname()
	af = aifc.open(fn, 'r')
	print af.getparams()
	p = Play_Audio_mac()
	p.setoutrate(af.getframerate())
	p.setsampwidth(af.getsampwidth())
	p.setnchannels(af.getnchannels())
	BUFSIZ = 10000
	while 1:
		data = af.readframes(BUFSIZ)
		if not data: break
		p.writeframes(data)
		print 'wrote', len(data), 'space', p.getfillable()
	p.wait()

if __name__ == '__main__':
	test()