def play(self): if _debug: print('play') with context.lock: context.async_operation( pa.pa_stream_cork(self.stream, 0, pa.pa_stream_success_cb_t(0), None) ) # If whole stream has already been written, trigger immediate # playback. if self._underflow_is_eos: context.async_operation( pa.pa_stream_trigger(self.stream, pa.pa_stream_success_cb_t(0), None) ) if self._buffer_underflow: self._write_cb(self.stream, None, None) self._playing = True
def _write_cb(self, stream, bytes, data): # If number of bytes is not supplied, query PulseAudio for it if bytes is None: bytes = pa.pa_stream_writable_size(self.stream) if _debug: print('write callback: %d bytes' % bytes) # Asynchronously update time if self._events: context.async_operation( pa.pa_stream_update_timing_info(self.stream, self._success_cb_func, None) ) # Grab next audio packet, or leftovers from last callback. if self._buffered_audio_data: audio_data = self._buffered_audio_data self._buffered_audio_data = None else: audio_data = self.source_group.get_audio_data(bytes) seek_flag = pa.PA_SEEK_RELATIVE if self._clear_write: if _debug: print('seek PA_SEEK_RELATIVE_ON_READ') seek_flag = pa.PA_SEEK_RELATIVE_ON_READ self._clear_write = False # Keep writing packets until `bytes` is depleted while audio_data and bytes > 0: if _debug: print('packet', audio_data.timestamp) if _debug and audio_data.events: print('events', audio_data.events) for event in audio_data.events: event_index = self._write_index + event.timestamp * \ self.source_group.audio_format.bytes_per_second self._events.append((event_index, event)) consumption = min(bytes, audio_data.length) check( pa.pa_stream_write(self.stream, audio_data.data, consumption, pa.pa_free_cb_t(0), # Data is copied 0, seek_flag) ) seek_flag = pa.PA_SEEK_RELATIVE self._read_index_valid = True self._timestamps.append((self._write_index, audio_data.timestamp)) self._write_index += consumption self._underflow_is_eos = False self._buffer_underflow = False if _debug: print('write', consumption) if consumption < audio_data.length: audio_data.consume(consumption, self.source_group.audio_format) self._buffered_audio_data = audio_data break bytes -= consumption if bytes > 0: audio_data = self.source_group.get_audio_data(bytes) #XXX name change if not audio_data: # Whole source group has been written. Any underflow encountered # after now is the EOS. self._underflow_is_eos = True # In case the source group wasn't long enough to prebuffer stream # to PA's satisfaction, trigger immediate playback (has no effect # if stream is already playing). if self._playing: context.async_operation( pa.pa_stream_trigger(self.stream, pa.pa_stream_success_cb_t(0), None) ) self._process_events()