mopidy/mopidy/gstreamer.py
2011-04-25 01:31:28 +02:00

207 lines
7.0 KiB
Python

import pygst
pygst.require('0.10')
import gst
import logging
from pykka.actor import ThreadingActor
from pykka.registry import ActorRegistry
from mopidy import settings
from mopidy.backends.base import Backend
logger = logging.getLogger('mopidy.outputs.gstreamer')
class GStreamer(ThreadingActor):
"""
Audio output through `GStreamer <http://gstreamer.freedesktop.org/>`_.
**Settings:**
- :attr:`mopidy.settings.GSTREAMER_AUDIO_SINK`
"""
def __init__(self):
self.gst_pipeline = None
def on_start(self):
self._setup_gstreamer()
def _setup_gstreamer(self):
"""
**Warning:** :class:`GStreamerOutput` requires
:class:`mopidy.utils.process.GObjectEventThread` to be running. This is
not enforced by :class:`GStreamerOutput` itself.
"""
base_pipeline = ' ! '.join([
'audioconvert name=convert',
'volume name=volume',
'taginject name=tag',
'tee name=tee',
])
logger.debug(u'Setting up base GStreamer pipeline: %s', base_pipeline)
self.gst_pipeline = gst.parse_launch(base_pipeline)
self.gst_tee = self.gst_pipeline.get_by_name('tee')
self.gst_convert = self.gst_pipeline.get_by_name('convert')
self.gst_volume = self.gst_pipeline.get_by_name('volume')
self.gst_taginject = self.gst_pipeline.get_by_name('tag')
self.gst_uridecodebin = gst.element_factory_make('uridecodebin', 'uri')
self.gst_uridecodebin.connect('pad-added', self._process_new_pad,
self.gst_convert.get_pad('sink'))
self.gst_pipeline.add(self.gst_uridecodebin)
localaudio = settings.GSTREAMER_AUDIO_SINK
shoutcast = self._build_shoutcast_description()
if localaudio:
self._add_output(localaudio)
if shoutcast:
self._add_output(shoutcast)
if not localaudio and not shoutcast:
logger.error('No proper output channels have been setup.')
self._add_output('fakesink')
# Setup bus and message processor
gst_bus = self.gst_pipeline.get_bus()
gst_bus.add_signal_watch()
gst_bus.connect('message', self._process_gstreamer_message)
def _add_output(self, description):
bin = 'queue ! %s' % description
logger.debug('Adding output bin to tee: %s', bin)
output = gst.parse_bin_from_description(bin, True)
self.gst_pipeline.add(output)
output.sync_state_with_parent()
gst.element_link_many(self.gst_tee, output)
def _build_shoutcast_description(self):
if settings.SHOUTCAST_OVERRIDE:
return settings.SHOUTCAST_OVERRIDE
if not settings.SHOUTCAST_SERVER:
return None
description = ['audioconvert ! %s ! shout2send' % settings.SHOUTCAST_ENCODER]
options = {
u'ip': settings.SHOUTCAST_SERVER,
u'mount': settings.SHOUTCAST_MOUNT,
u'port': settings.SHOUTCAST_PORT,
u'username': settings.SHOUTCAST_USER,
u'password': settings.SHOUTCAST_PASSWORD,
}
for key, value in sorted(options.items()):
if value:
description.append('%s="%s"' % (key, value))
return u' '.join(description)
def _process_new_pad(self, source, pad, target_pad):
pad.link(target_pad)
def _process_gstreamer_message(self, bus, message):
"""Process messages from GStreamer."""
if message.type == gst.MESSAGE_EOS:
logger.debug(u'GStreamer signalled end-of-stream. '
'Telling backend ...')
self._get_backend().playback.on_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 the backend here? Can we
# differentiate on how serious the error is?
def _get_backend(self):
backend_refs = ActorRegistry.get_by_class(Backend)
assert len(backend_refs) == 1, 'Expected exactly one running backend.'
return backend_refs[0].proxy()
def play_uri(self, uri):
"""Play audio at URI"""
self.set_state('READY')
self.gst_uridecodebin.set_property('uri', uri)
return self.set_state('PLAYING')
def deliver_data(self, caps_string, data):
"""Deliver audio data to be played"""
source = self.gst_pipeline.get_by_name('source')
caps = gst.caps_from_string(caps_string)
buffer_ = gst.Buffer(buffer(data))
buffer_.set_caps(caps)
source.set_property('caps', caps)
source.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('source').emit('end-of-stream')
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
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 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]"""
return int(self.gst_volume.get_property('volume') * 100)
def set_volume(self, volume):
"""Set volume in range [0..100]"""
self.gst_volume.set_property('volume', volume / 100.0)
return True
def set_metadata(self, track):
tags = u'artist="%(artist)s",title="%(title)s"' % {
'artist': u', '.join([a.name for a in track.artists]),
'title': track.name,
}
logger.debug('Setting tags to: %s', tags)
self.gst_taginject.set_property('tags', tags)