def get_buffer(self):
if not self:
buffer = al.ALuint()
al.alGenBuffers(1, buffer)
else:
buffer = self.pop(0)
return buffer
def __init__(self, source_group, player):
super(OpenALAudioPlayer, self).__init__(source_group, player)
audio_format = source_group.audio_format
try:
self._al_format = format_map[(audio_format.channels,
audio_format.sample_size)]
except KeyError:
raise OpenALException('Unsupported audio format.')
self._al_source = al.ALuint()
al.alGenSources(1, self._al_source)
# Lock policy: lock all instance vars (except constants). (AL calls
# are locked on context).
self._lock = threading.RLock()
# Cursor positions, like DSound and Pulse drivers, refer to a
# hypothetical infinite-length buffer. Cursor units are in bytes.
# Cursor position of current (head) AL buffer
self._buffer_cursor = 0
# Estimated playback cursor position (last seen)
self._play_cursor = 0
# Cursor position of end of queued AL buffer.
self._write_cursor = 0
# List of currently queued buffer sizes (in bytes)
self._buffer_sizes = []
# List of currently queued buffer timestamps
self._buffer_timestamps = []
# Timestamp at end of last written buffer (timestamp to return in case
# of underrun)
self._underrun_timestamp = None
# List of (cursor, MediaEvent)
self._events = []
# Desired play state (True even if stopped due to underrun)
self._playing = False
# Has source group EOS been seen (and hence, event added to queue)?
self._eos = False
# OpenAL 1.0 timestamp interpolation: system time of current buffer
# playback (best guess)
if not context.have_1_1:
self._buffer_system_time = time.time()
self.refill(self._ideal_buffer_size)
def dequeueBuffer(self, alSource, buffer):
"""A buffer has finished playing, free it."""
assert context._lock.locked()
sourceBuffs = self._sources[alSource.value]
if buffer in map(lambda x: x.value, sourceBuffs):
#sourceBuffs.remove(buffer)
self._sources[alSource.value] = [
b for b in sourceBuffs if b.value != buffer
]
self._buffers.append(al.ALuint(buffer))
elif _debug_buffers:
# This seems to be the problem with Mac OS X - The buffers are
# dequeued, but they're not _actually_ buffers. In other words,
# there's some leakage, so after awhile, things break.
print("Bad buffer: " + str(buffer))
def refill(self, write_size):
if _debug:
print 'refill', write_size
self._lock.acquire()
while write_size > self._min_buffer_size:
audio_data = self.source_group.get_audio_data(write_size)
if not audio_data:
self._eos = True
self._events.append(
(self._write_cursor, mt_media.MediaEvent(0, 'on_eos')))
self._events.append(
(self._write_cursor,
mt_media.MediaEvent(0, 'on_source_group_eos')))
break
for event in audio_data.events:
cursor = self._write_cursor + event.timestamp * \
self.source_group.audio_format.bytes_per_second
self._events.append((cursor, event))
buffer = al.ALuint()
context.lock()
al.alGenBuffers(1, buffer)
al.alBufferData(buffer, self._al_format, audio_data.data,
audio_data.length,
self.source_group.audio_format.sample_rate)
al.alSourceQueueBuffers(self._al_source, 1, ctypes.byref(buffer))
context.unlock()
self._write_cursor += audio_data.length
self._buffer_sizes.append(audio_data.length)
self._buffer_timestamps.append(audio_data.timestamp)
write_size -= audio_data.length
# Check for underrun stopping playback
if self._playing:
state = al.ALint()
context.lock()
al.alGetSourcei(self._al_source, al.AL_SOURCE_STATE, state)
if state.value != al.AL_PLAYING:
if _debug:
print 'underrun'
al.alSourcePlay(self._al_source)
context.unlock()
self._lock.release()
def getBuffers(self, alSource, i):
"""Returns an array containing i buffer names. The returned list must
not be modified in any way, and may get changed by subsequent calls to
getBuffers.
"""
assert context._lock.locked()
buffs = []
try:
while i > 0:
b = self._buffers.pop()
if not al.alIsBuffer(b):
# Protect against implementations that DO free buffers
# when they delete a source - carry on.
if _debug_buffers:
print("Found a bad buffer")
continue
buffs.append(b)
i -= 1
except IndexError:
while i > 0:
buffer = al.ALuint()
al.alGenBuffers(1, buffer)
if _debug_buffers:
error = al.alGetError()
if error != 0:
print("GEN BUFFERS: " + str(error))
buffs.append(buffer)
i -= 1
alSourceVal = alSource.value
if alSourceVal not in self._sources:
self._sources[alSourceVal] = buffs
else:
self._sources[alSourceVal].extend(buffs)
return buffs
return True
if __name__ == '__main__':
import sys
# openal
device = alc.alcOpenDevice(None)
if not device:
raise Exception('No OpenAL device.')
alcontext = alc.alcCreateContext(device, None)
alc.alcMakeContextCurrent(alcontext)
source = al.ALuint()
al.alGenSources(1, source)
pool = BufferPool()
# avcodec
init()
container = open(sys.argv[1])
stream = get_audio_stream(container)
decoder = AVCodecDecoder(container, stream)
while True:
buffer = pool.get_buffer()
if not decoder.fill_buffer(buffer):
break
class AVCodecDecoder:
def __init__(self, container, stream):
self.codec = get_codec(container, stream)
if self.codec.contents.channels == 1:
self.buffer_format = al.AL_FORMAT_MONO16
elif self.codec.contents.channels == 2:
self.buffer_format = al.AL_FORMAT_STEREO16
else:
raise Exception('Invalid number of channels')
self.sample_rate = self.codec.contents.sample_rate
self.container = container
self.stream = stream
self.packet = avformat.AVPacket()
self.sample_buffer = \
(ctypes.c_int16 * (avcodec.AVCODEC_MAX_AUDIO_FRAME_SIZE / 2))()
self.read_packet()
def read_packet(self):
while True:
if self.packet.data:
self.packet.data = None
self.packet.size = 0
if avformat.av_read_packet(self.container, self.packet) < 0:
break
if self.packet.stream_index == self.stream:
break
self.packet_data = self.packet.data
self.packet_size = self.packet.size
def fill_buffer(self, buffer):
if self.packet_size <= 0:
self.read_packet()
if self.packet_size == 0: # EOS
return False
sample_buffer_size = ctypes.c_int()
len = avcodec.avcodec_decode_audio(self.codec, self.sample_buffer,
sample_buffer_size,
self.packet_data, self.packet_size)
if len < 0:
# Error, skip frame
raise Exception('frame error TODO')
if sample_buffer_size.value > 0:
al.alBufferData(buffer, self.buffer_format, self.sample_buffer,
sample_buffer_size.value, self.sample_rate)
# Advance buffer pointer
self.packet_data = ctypes.c_uint8.from_address(
ctypes.addressof(self.packet_data) + len)
self.packet_size -= len
return True
import sys
# openal
device = alc.alcOpenDevice(None)
if not device:
raise Exception('No OpenAL device.')
alcontext = alc.alcCreateContext(device, None)
alc.alcMakeContextCurrent(alcontext)
source = al.ALuint()
al.alGenSources(1, source)
pool = BufferPool()
# avcodec
init()
container = open(sys.argv[1])
stream = get_audio_stream(container)
decoder = AVCodecDecoder(container, stream)
while True:
buffer = pool.get_buffer()
if not decoder.fill_buffer(buffer):
break
al.alSourceQueueBuffers(source, 1, buffer)
al.alSourcePlay(source)
while True:
value = al.ALint()
al.alGetSourcei(source, al.AL_SOURCE_STATE, value)
if value.value == al.AL_STOPPED:
break
time.sleep(1)
