Files
whipper-gui/morituri/common/gstreamer.py
Thomas Vander Stichele 1ce46272a9 * morituri/test/test_common_encode.py:
Generate an actual file by spawning gst-launch; otherwise
	  with proper error handling we get an error from wavparse that
	  there is not enough data to typefind.
	* morituri/common/gstreamer.py:
	  Move the gst import to start() and set it as a class attribute.
	  Document methods.
	* morituri/common/encode.py:
	  Convert EncodeTask to a GstPipelineTask.
2011-05-23 14:57:16 +00:00

119 lines
3.5 KiB
Python

# -*- Mode: Python; test-case-name: morituri.test.test_common_gstreamer -*-
# vi:si:et:sw=4:sts=4:ts=4
# Morituri - for those about to RIP
# Copyright (C) 2009 Thomas Vander Stichele
# This file is part of morituri.
#
# morituri is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# morituri is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with morituri. If not, see <http://www.gnu.org/licenses/>.
from morituri.common import common, task
class GstException(Exception):
def __init__(self, gerror, debug):
self.args = (gerror, debug, )
self.gerror = gerror
self.debug = debug
class GstPipelineTask(task.Task):
"""
I am a base class for tasks that use a GStreamer pipeline.
I handle errors and raise them appropriately.
@cvar gst: the GStreamer module, so code does not have to import gst
as a module in code everywhere to avoid option stealing.
"""
gst = None
def start(self, runner):
import gst
self.gst = gst
task.Task.start(self, runner)
desc = self.getPipelineDesc()
self.debug('creating pipeline %r', desc)
self.pipeline = self.gst.parse_launch(desc)
self._bus = self.pipeline.get_bus()
self.gst.debug('got bus %r' % self._bus)
# a signal watch calls callbacks from an idle loop
# self._bus.add_signal_watch()
# sync emission triggers sync-message signals which calls callbacks
# from the thread that signals, but happens immediately
self._bus.enable_sync_message_emission()
self._bus.connect('sync-message::eos', self.bus_eos_cb)
self._bus.connect('sync-message::tag', self.bus_tag_cb)
self._bus.connect('sync-message::error', self.bus_error_cb)
self.parsed()
self.debug('pausing pipeline')
self.pipeline.set_state(self.gst.STATE_PAUSED)
# FIXME: this can block
self.pipeline.get_state()
self.debug('paused pipeline')
if not self.exception:
self.paused()
else:
raise self.exception
def getPipelineDesc(self):
raise NotImplementedError
def parsed(self):
"""
Called after parsing the pipeline but before setting it to paused.
"""
pass
def paused(self):
"""
Called after pipeline is paused
"""
pass
def bus_eos_cb(self, bus, message):
"""
Called synchronously (ie from messaging thread) on eos message.
Override me to handle eos
"""
pass
def bus_tag_cb(self, bus, message):
"""
Called synchronously (ie from messaging thread) on tag message.
Override me to handle tags.
"""
pass
def bus_error_cb(self, bus, message):
"""
Called synchronously (ie from messaging thread) on error message.
"""
exc = GstException(*message.parse_error())
self.setAndRaiseException(exc)
# FIXME: why is this commented ?
# self.gst.debug('error, scheduling stop')
#self.runner.schedule(0, self.stop)