def stop(self):
if _debug:
print('stop')
with context.lock:
context.async_operation(
pa.pa_stream_cork(self.stream, 1,
pa.pa_stream_success_cb_t(0), None)
)
self._playing = False
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()
def __init__(self, source_group, player):
super(PulseAudioPlayer, self).__init__(source_group, player)
self._events = []
self._timestamps = [] # List of (ref_time, timestamp)
self._write_index = 0 # Current write index (tracked manually)
self._read_index_valid = False # True only if buffer has non-stale data
self._clear_write = False
self._buffered_audio_data = None
self._underflow_is_eos = False
self._buffer_underflow = False
self._playing = False
audio_format = source_group.audio_format
assert audio_format
# Create sample_spec
sample_spec = pa.pa_sample_spec()
if audio_format.sample_size == 8:
sample_spec.format = pa.PA_SAMPLE_U8
elif audio_format.sample_size == 16:
if sys.byteorder == 'little':
sample_spec.format = pa.PA_SAMPLE_S16LE
else:
sample_spec.format = pa.PA_SAMPLE_S16BE
else:
raise MediaException('Unsupported sample size')
sample_spec.rate = audio_format.sample_rate
sample_spec.channels = audio_format.channels
channel_map = None
self.sample_rate = audio_format.sample_rate
with context.lock:
# Create stream
self.stream = pa.pa_stream_new(context._context,
str(id(self)).encode('ASCII'),
sample_spec,
channel_map)
check_not_null(self.stream)
pa.pa_stream_ref(self.stream)
# Callback trampoline for success operations
self._success_cb_func = pa.pa_stream_success_cb_t(self._success_cb)
self._context_success_cb_func = \
pa.pa_context_success_cb_t(self._context_success_cb)
# Callback for underflow (to detect EOS when expected pa_timestamp
# does not get reached).
self._underflow_cb_func = \
pa.pa_stream_notify_cb_t(self._underflow_cb)
pa.pa_stream_set_underflow_callback(self.stream,
self._underflow_cb_func, None)
# Callback for data write
self._write_cb_func = pa.pa_stream_request_cb_t(self._write_cb)
pa.pa_stream_set_write_callback(self.stream,
self._write_cb_func, None)
# Connect to sink
device = None
buffer_attr = None
flags = (pa.PA_STREAM_START_CORKED |
pa.PA_STREAM_INTERPOLATE_TIMING |
pa.PA_STREAM_VARIABLE_RATE)
sync_stream = None # TODO use this
check(
pa.pa_stream_connect_playback(self.stream,
device,
buffer_attr,
flags,
None,
sync_stream)
)
# Wait for stream readiness
self._state_cb_func = pa.pa_stream_notify_cb_t(self._state_cb)
pa.pa_stream_set_state_callback(self.stream,
self._state_cb_func, None)
while pa.pa_stream_get_state(self.stream) == pa.PA_STREAM_CREATING:
context.wait()
if pa.pa_stream_get_state(self.stream) != pa.PA_STREAM_READY:
check(-1)
if _debug:
print('stream ready')
