mopidy/mopidy/outputs/gstreamer.py
2010-10-24 23:51:21 +02:00

285 lines
10 KiB
Python

import gobject
gobject.threads_init()
import pygst
pygst.require('0.10')
import gst
import logging
import multiprocessing
from mopidy import settings
from mopidy.outputs.base import BaseOutput
from mopidy.utils.process import (BaseThread, pickle_connection,
unpickle_connection)
logger = logging.getLogger('mopidy.outputs.gstreamer')
class GStreamerOutput(BaseOutput):
"""
Audio output through GStreamer.
Starts :class:`GStreamerMessagesThread` and :class:`GStreamerPlayerThread`.
**Settings:**
- :attr:`mopidy.settings.GSTREAMER_AUDIO_SINK`
"""
def __init__(self, *args, **kwargs):
super(GStreamerOutput, self).__init__(*args, **kwargs)
# Start a helper thread that can run the gobject.MainLoop
self.messages_thread = GStreamerMessagesThread(self.core_queue)
# Start a helper thread that can process the output_queue
self.output_queue = multiprocessing.Queue()
self.player_thread = GStreamerPlayerThread(self.core_queue,
self.output_queue)
def start(self):
self.messages_thread.start()
self.player_thread.start()
def destroy(self):
self.messages_thread.destroy()
self.player_thread.destroy()
def process_message(self, message):
assert message['to'] == 'output', \
u'Message recipient must be "output".'
self.output_queue.put(message)
def _send_recv(self, message):
(my_end, other_end) = multiprocessing.Pipe()
message['to'] = 'output'
message['reply_to'] = pickle_connection(other_end)
self.process_message(message)
my_end.poll(None)
return my_end.recv()
def _send(self, message):
message['to'] = 'output'
self.process_message(message)
def play_uri(self, uri):
return self._send_recv({'command': 'play_uri', 'uri': uri})
def deliver_data(self, capabilities, data):
return self._send({
'command': 'deliver_data',
'caps': capabilities,
'data': data,
})
def end_of_data_stream(self):
return self._send({'command': 'end_of_data_stream'})
def get_position(self):
return self._send_recv({'command': 'get_position'})
def set_position(self, position):
return self._send_recv({'command': 'set_position',
'position': position})
def set_state(self, state):
return self._send_recv({'command': 'set_state', 'state': state})
def get_volume(self):
return self._send_recv({'command': 'get_volume'})
def set_volume(self, volume):
return self._send_recv({'command': 'set_volume', 'volume': volume})
class GStreamerMessagesThread(BaseThread):
def __init__(self, core_queue):
super(GStreamerMessagesThread, self).__init__(core_queue)
self.name = u'GStreamerMessagesThread'
def run_inside_try(self):
gobject.MainLoop().run()
class GStreamerPlayerThread(BaseThread):
"""
A process for all work related to GStreamer.
The main loop processes events from both Mopidy and GStreamer.
Make sure this subprocess is started by the MainThread in the top-most
parent process, and not some other thread. If not, we can get into the
problems described at
http://jameswestby.net/weblog/tech/14-caution-python-multiprocessing-and-glib-dont-mix.html.
"""
def __init__(self, core_queue, output_queue):
super(GStreamerPlayerThread, self).__init__(core_queue)
self.name = u'GStreamerPlayerThread'
self.output_queue = output_queue
self.gst_pipeline = None
def run_inside_try(self):
self.setup()
while True:
message = self.output_queue.get()
self.process_mopidy_message(message)
def setup(self):
logger.debug(u'Setting up GStreamer pipeline')
self.gst_pipeline = gst.parse_launch(' ! '.join([
'audioconvert name=convert',
'volume name=volume',
settings.GSTREAMER_AUDIO_SINK,
]))
pad = self.gst_pipeline.get_by_name('convert').get_pad('sink')
if settings.BACKENDS[0] == 'mopidy.backends.local.LocalBackend':
uri_bin = gst.element_factory_make('uridecodebin', 'uri')
uri_bin.connect('pad-added', self.process_new_pad, pad)
self.gst_pipeline.add(uri_bin)
else:
app_src = gst.element_factory_make('appsrc', 'appsrc')
app_src_caps = gst.Caps("""
audio/x-raw-int,
endianness=(int)1234,
channels=(int)2,
width=(int)16,
depth=(int)16,
signed=(boolean)true,
rate=(int)44100""")
app_src.set_property('caps', app_src_caps)
self.gst_pipeline.add(app_src)
app_src.get_pad('src').link(pad)
# Setup bus and message processor
gst_bus = self.gst_pipeline.get_bus()
gst_bus.add_signal_watch()
gst_bus.connect('message', self.process_gst_message)
def process_new_pad(self, source, pad, target_pad):
pad.link(target_pad)
def process_mopidy_message(self, message):
"""Process messages from the rest of Mopidy."""
if message['command'] == 'play_uri':
response = self.play_uri(message['uri'])
connection = unpickle_connection(message['reply_to'])
connection.send(response)
elif message['command'] == 'deliver_data':
self.deliver_data(message['caps'], message['data'])
elif message['command'] == 'end_of_data_stream':
self.end_of_data_stream()
elif message['command'] == 'set_state':
response = self.set_state(message['state'])
connection = unpickle_connection(message['reply_to'])
connection.send(response)
elif message['command'] == 'get_volume':
volume = self.get_volume()
connection = unpickle_connection(message['reply_to'])
connection.send(volume)
elif message['command'] == 'set_volume':
response = self.set_volume(message['volume'])
connection = unpickle_connection(message['reply_to'])
connection.send(response)
elif message['command'] == 'set_position':
response = self.set_position(message['position'])
connection = unpickle_connection(message['reply_to'])
connection.send(response)
elif message['command'] == 'get_position':
response = self.get_position()
connection = unpickle_connection(message['reply_to'])
connection.send(response)
else:
logger.warning(u'Cannot handle message: %s', message)
def process_gst_message(self, bus, message):
"""Process messages from GStreamer."""
if message.type == gst.MESSAGE_EOS:
logger.debug(u'GStreamer signalled end-of-stream. '
'Sending end_of_track to core_queue ...')
self.core_queue.put({'command': 'end_of_track'})
elif message.type == gst.MESSAGE_ERROR:
self.set_state('NULL')
error, debug = message.parse_error()
logger.error(u'%s %s', error, debug)
# FIXME Should we send 'stop_playback' to core here? Can we
# differentiate on how serious the error is?
def play_uri(self, uri):
"""Play audio at URI"""
self.set_state('READY')
self.gst_pipeline.get_by_name('uri').set_property('uri', uri)
return self.set_state('PLAYING')
def deliver_data(self, caps_string, data):
"""Deliver audio data to be played"""
app_src = self.gst_pipeline.get_by_name('appsrc')
caps = gst.caps_from_string(caps_string)
buffer_ = gst.Buffer(buffer(data))
buffer_.set_caps(caps)
app_src.set_property('caps', caps)
app_src.emit('push-buffer', buffer_)
def end_of_data_stream(self):
"""
Add end-of-stream token to source.
We will get a GStreamer message when the stream playback reaches the
token, and can then do any end-of-stream related tasks.
"""
self.gst_pipeline.get_by_name('appsrc').emit('end-of-stream')
def set_state(self, state_name):
"""
Set the GStreamer state. Returns :class:`True` if successful.
.. digraph:: gst_state_transitions
"NULL" -> "READY"
"PAUSED" -> "PLAYING"
"PAUSED" -> "READY"
"PLAYING" -> "PAUSED"
"READY" -> "NULL"
"READY" -> "PAUSED"
:param state_name: NULL, READY, PAUSED, or PLAYING
:type state_name: string
:rtype: :class:`True` or :class:`False`
"""
result = self.gst_pipeline.set_state(
getattr(gst, 'STATE_' + state_name))
if result == gst.STATE_CHANGE_FAILURE:
logger.warning('Setting GStreamer state to %s: failed', state_name)
return False
else:
logger.debug('Setting GStreamer state to %s: OK', state_name)
return True
def get_volume(self):
"""Get volume in range [0..100]"""
gst_volume = self.gst_pipeline.get_by_name('volume')
return int(gst_volume.get_property('volume') * 100)
def set_volume(self, volume):
"""Set volume in range [0..100]"""
gst_volume = self.gst_pipeline.get_by_name('volume')
gst_volume.set_property('volume', volume / 100.0)
return True
def set_position(self, position):
self.gst_pipeline.get_state() # block until state changes are done
handeled = self.gst_pipeline.seek_simple(gst.Format(gst.FORMAT_TIME),
gst.SEEK_FLAG_FLUSH, position * gst.MSECOND)
self.gst_pipeline.get_state() # block until seek is done
return handeled
def get_position(self):
try:
position = self.gst_pipeline.query_position(gst.FORMAT_TIME)[0]
return position // gst.MSECOND
except gst.QueryError, e:
logger.error('time_position failed: %s', e)
return 0