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)
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)
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 al.alSourceQueueBuffers(source, 1, buffer)