def check_not_null(value):
if not value:
error = pa.pa_context_errno(context._context)
raise MediaException(pa.pa_strerror(error))
return value
def check(result):
if result < 0:
error = pa.pa_context_errno(context._context)
raise MediaException(pa.pa_strerror(error))
return result
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._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
try:
context.lock()
# Create stream
self.stream = pa.pa_stream_new(context._context, str(id(self)),
sample_spec, channel_map)
check_not_null(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)
finally:
context.unlock()
self.set_volume(self._volume)
if _debug:
print 'stream ready'
def __init__(self, audio_format):
super().__init__(audio_format)
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
device = None
buffer_attr = None
flags = (pa.PA_STREAM_START_CORKED | pa.PA_STREAM_INTERPOLATE_TIMING)
volume = None
# TODO should expose sync_stream, since soundspace example sounds
# noticeably out of sync with PA.
sync_stream = None
try:
driver_listener.lock()
self.stream = pa.pa_stream_new(context, str(id(self)), sample_spec,
channel_map)
check_not_null(self.stream)
check(
pa.pa_stream_connect_playback(self.stream, device, buffer_attr,
flags, volume, sync_stream))
finally:
driver_listener.unlock()
self._timestamps = list() # List of (pa_time, timestamp)
self._write_time = 0.0
self._timestamp = 0.0
self._timestamp_pa_time = 0.0
self._eos_count = 0
self._ended = False
self._ended_underflowed = False
# Callback trampoline for success operations
self._success_cb_func = pa.pa_stream_success_cb_t(self._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)
# 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)
driver_listener.lock()
while pa.pa_stream_get_state(self.stream) == pa.PA_STREAM_CREATING:
driver_listener.wait()
driver_listener.unlock()
if _debug:
print('stream ready')