oxtimeline/oxgst/singledecodebin.py
2010-08-20 12:11:17 +02:00

462 lines
16 KiB
Python

# -*- coding: utf-8 -*-
# -*- Mode: Python; -*-
# vi:si:et:sw=4:sts=4:ts=4
#
# pitivi/elements/singledecodebin.py
#
# Copyright (c) 2005, Edward Hervey <bilboed@bilboed.com>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This program 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this program; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.
"""
Single-stream queue-less decodebin
"""
import gobject
import gst
def pad_compatible_stream(pad, stream):
"""
Checks whether the given pad is compatible with the given stream.
@param pad: The pad
@type pad: C{gst.Pad}
@param stream: The stream to match against.
@type stream: L{MultimediaStream}
@return: Whether the pad is compatible with the given stream
@rtype: C{bool}
"""
if stream == None:
# yes, None is the magical stream that takes everything
return True
# compatible caps
if stream.caps:
return not stream.caps.intersect(pad.get_caps()).is_empty()
raise Exception("Can't figure out compatibility since the stream doesn't have any caps")
class CachedFactoryList(object):
def __init__(self, factoryFilter=None):
self._factoryFilter = factoryFilter
self._factories = None
self._registry = gst.registry_get_default()
self._registry.connect("feature-added", self._registryFeatureAddedCb)
def get(self):
if self._factories is None:
self._buildFactories()
return self._factories
def _buildFactories(self):
# build the cache
#log.debug("utils", "Getting factories list")
factories = self._registry.get_feature_list(gst.ElementFactory)
if self._factoryFilter is not None:
#log.debug("utils", "filtering")
factories = filter(self._factoryFilter, factories)
#log.debug("utils", "Sorting by rank")
factories.sort(key=lambda factory: factory.get_rank(), reverse=True)
self._factories = factories
#log.debug("utils", "Cached factories is now %r", self._factories)
def _registryFeatureAddedCb(self, registry, feature):
# invalidate the cache
#log.warning("utils", "New feature added, invalidating cached factories")
self._factories = None
def is_raw(caps):
""" returns True if the caps are RAW """
rep = caps.to_string()
valid = ["video/x-raw", "audio/x-raw", "text/plain", "text/x-pango-markup"]
for val in valid:
if rep.startswith(val):
return True
return False
def factoryFilter(factory):
if factory.get_rank() < 64 :
return False
klass = factory.get_klass()
for cat in ("Demuxer", "Decoder", "Parse"):
if cat in klass:
return True
return False
_factoryCache = CachedFactoryList(factoryFilter)
class SingleDecodeBin(gst.Bin):
"""
A variant of decodebin.
* Only outputs one stream
* Doesn't contain any internal queue
"""
QUEUE_SIZE = 1 * gst.SECOND
__gsttemplates__ = (
gst.PadTemplate ("sinkpadtemplate",
gst.PAD_SINK,
gst.PAD_ALWAYS,
gst.caps_new_any()),
gst.PadTemplate ("srcpadtemplate",
gst.PAD_SRC,
gst.PAD_SOMETIMES,
gst.caps_new_any())
)
def __init__(self, caps=None, uri=None, stream=None, *args, **kwargs):
gst.Bin.__init__(self, *args, **kwargs)
if not caps:
caps = gst.caps_new_any()
self.caps = caps
self.stream = stream
self.typefind = gst.element_factory_make("typefind", "internal-typefind")
self.add(self.typefind)
self.uri = uri
if self.uri and gst.uri_is_valid(self.uri):
self.urisrc = gst.element_make_from_uri(gst.URI_SRC, uri, "urisrc")
self.log("created urisrc %s / %r" % (self.urisrc.get_name(),
self.urisrc))
self.add(self.urisrc)
# Set the blocksize to 512kbytes, this will only matter for push-based sources
if hasattr(self.urisrc.props, "blocksize"):
self.urisrc.props.blocksize = 524288
self.urisrc.link_pads_full("src", self.typefind, "sink",
gst.PAD_LINK_CHECK_NOTHING)
else:
self._sinkpad = gst.GhostPad("sink", self.typefind.get_pad("sink"))
self._sinkpad.set_active(True)
self.add_pad(self._sinkpad)
self.typefind.connect("have_type", self._typefindHaveTypeCb)
self._srcpad = None
self._dynamics = []
self._validelements = [] #added elements
self.debug("stream:%r" % self.stream)
self.pending_newsegment = False
self.eventProbeId = None
## internal methods
def _controlDynamicElement(self, element):
self.log("element:%s" % element.get_name())
self._dynamics.append(element)
element.connect("pad-added", self._dynamicPadAddedCb)
element.connect("no-more-pads", self._dynamicNoMorePadsCb)
def _findCompatibleFactory(self, caps):
"""
Returns a list of factories (sorted by rank) which can take caps as
input. Returns empty list if none are compatible
"""
self.debug("caps:%s" % caps.to_string())
res = []
for factory in _factoryCache.get():
for template in factory.get_static_pad_templates():
if template.direction == gst.PAD_SINK:
intersect = caps.intersect(template.static_caps.get())
if not intersect.is_empty():
res.append(factory)
break
self.debug("returning %r" % res)
return res
def _closeLink(self, element):
"""
Inspects element and tries to connect something on the srcpads.
If there are dynamic pads, it sets up a signal handler to
continue autoplugging when they become available.
"""
to_connect = []
dynamic = False
templates = element.get_pad_template_list()
for template in templates:
if not template.direction == gst.PAD_SRC:
continue
if template.presence == gst.PAD_ALWAYS:
pad = element.get_pad(template.name_template)
to_connect.append(pad)
elif template.presence == gst.PAD_SOMETIMES:
pad = element.get_pad(template.name_template)
if pad:
to_connect.append(pad)
else:
dynamic = True
else:
self.log("Template %s is a request pad, ignoring" % pad.name_template)
if dynamic:
self.debug("%s is a dynamic element" % element.get_name())
self._controlDynamicElement(element)
for pad in to_connect:
self._closePadLink(element, pad, pad.get_caps())
def _isDemuxer(self, element):
if not 'Demux' in element.get_factory().get_klass():
return False
potential_src_pads = 0
for template in element.get_pad_template_list():
if template.direction != gst.PAD_SRC:
continue
if template.presence == gst.PAD_REQUEST or \
"%" in template.name_template:
potential_src_pads += 2
break
else:
potential_src_pads += 1
return potential_src_pads > 1
def _plugDecodingQueue(self, pad):
queue = gst.element_factory_make("queue")
queue.props.max_size_time = self.QUEUE_SIZE
queue.props.max_size_buffers = 3
self.add(queue)
queue.sync_state_with_parent()
pad.link_full(queue.get_pad("sink"), gst.PAD_LINK_CHECK_NOTHING)
pad = queue.get_pad("src")
return pad
def _tryToLink1(self, source, pad, factories):
"""
Tries to link one of the factories' element to the given pad.
Returns the element that was successfully linked to the pad.
"""
self.debug("source:%s, pad:%s , factories:%r" % (source.get_name(),
pad.get_name(),
factories))
if self._isDemuxer(source):
pad = self._plugDecodingQueue(pad)
result = None
for factory in factories:
element = factory.create()
if not element:
self.warning("weren't able to create element from %r" % factory)
continue
sinkpad = element.get_pad("sink")
if not sinkpad:
continue
self.add(element)
element.set_state(gst.STATE_READY)
try:
pad.link(sinkpad)
except:
element.set_state(gst.STATE_NULL)
self.remove(element)
continue
self._closeLink(element)
element.set_state(gst.STATE_PAUSED)
result = element
break
return result
def _closePadLink(self, element, pad, caps):
"""
Finds the list of elements that could connect to the pad.
If the pad has the desired caps, it will create a ghostpad.
If no compatible elements could be found, the search will stop.
"""
self.debug("element:%s, pad:%s, caps:%s" % (element.get_name(),
pad.get_name(),
caps.to_string()))
if caps.is_empty():
self.log("unknown type")
return
if caps.is_any():
self.log("type is not know yet, waiting")
return
self.debug("stream %r" % (self.stream))
if caps.intersect(self.caps) and (self.stream is None or
(self.stream.pad_name == get_pad_id(pad))):
# This is the desired caps
if not self._srcpad:
self._wrapUp(element, pad)
elif is_raw(caps) and pad_compatible_stream(pad, self.stream):
self.log ("not the target stream, but compatible")
if not self._srcpad:
self._wrapUp(element, pad)
elif is_raw(caps):
self.log("We hit a raw caps which isn't the wanted one")
# FIXME : recursively remove everything until demux/typefind
else:
# Find something
if len(caps) > 1:
self.log("many possible types, delaying")
return
facts = self._findCompatibleFactory(caps)
if not facts:
self.log("unknown type")
return
self._tryToLink1(element, pad, facts)
def _wrapUp(self, element, pad):
"""
Ghost the given pad of element.
Remove non-used elements.
"""
if self._srcpad:
return
self._markValidElements(element)
gobject.idle_add(self._removeUnusedElements, self.typefind)
if pad.props.caps is not None:
caps = pad.props.caps
else:
caps = pad.get_caps()
self._srcpad = gst.GhostPad("src", pad)
self._srcpad.set_active(True)
if caps.is_fixed():
self._exposePad(target=pad)
else:
self._blockPad(target=pad)
def _exposePad(self, target):
self.log("ghosting pad %s" % target.get_name())
self.add_pad(self._srcpad)
self.post_message(gst.message_new_state_dirty(self))
def _blockPad(self, target):
# don't pass target as an argument to set_blocked_async. Avoids
# triggering a bug in gst-python where pad_block_destroy_data calls
# CPython without acquiring the GIL
self._target = target
self._eventProbeId = target.add_event_probe(self._padEventCb)
self._srcpad.set_blocked_async(True, self._padBlockedCb)
def _unblockPad(self, target):
target.remove_event_probe(self._eventProbeId)
self._eventProbeId = None
self._srcpad.set_blocked_async(False, self._padBlockedCb)
def _padBlockedCb(self, ghost, blocked):
if not blocked:
if self.pending_newsegment is not None:
self._srcpad.push_event(self.pending_newsegment)
self.pending_newsegment = None
return
self._exposePad(target=self._target)
self._unblockPad(target=self._target)
def _padEventCb(self, pad, event):
if event.type == gst.EVENT_TAG:
self.debug("dropping TAG event")
return False
if event.type != gst.EVENT_NEWSEGMENT:
self.warning("first event: %s is not a NEWSEGMENT, bailing out" %
event)
self._exposePad(target=pad)
self._unblockPad(target=pad)
return True
self.debug("stored pending newsegment")
self.pending_newsegment = event
return False
def _markValidElements(self, element):
"""
Mark this element and upstreams as valid
"""
self.log("element:%s" % element.get_name())
if element == self.typefind:
return
self._validelements.append(element)
# find upstream element
pad = list(element.sink_pads())[0]
parent = pad.get_peer().get_parent()
self._markValidElements(parent)
def _removeUnusedElements(self, element):
"""
Remove unused elements connected to srcpad(s) of element
"""
self.log("element:%r" % element)
for pad in list(element.src_pads()):
if pad.is_linked():
peer = pad.get_peer().get_parent()
if isinstance(peer, gst.Element):
self._removeUnusedElements(peer)
if not peer in self._validelements:
self.log("removing %s" % peer.get_name())
pad.unlink(pad.get_peer())
peer.set_state(gst.STATE_NULL)
self.remove(peer)
def _cleanUp(self):
self.log("")
if self._srcpad:
self.remove_pad(self._srcpad)
self._srcpad = None
self._target = None
for element in self._validelements:
element.set_state(gst.STATE_NULL)
self.remove(element)
self._validelements = []
## Overrides
def do_change_state(self, transition):
self.debug("transition:%r" % transition)
res = gst.Bin.do_change_state(self, transition)
if transition == gst.STATE_CHANGE_PAUSED_TO_READY:
self._cleanUp()
return res
## Signal callbacks
def _typefindHaveTypeCb(self, typefind, probability, caps):
self.debug("probability:%d, caps:%s" % (probability, caps.to_string()))
self._closePadLink(typefind, typefind.get_pad("src"), caps)
## Dynamic element Callbacks
def _dynamicPadAddedCb(self, element, pad):
self.log("element:%s, pad:%s" % (element.get_name(), pad.get_name()))
if not self._srcpad:
self._closePadLink(element, pad, pad.get_caps())
def _dynamicNoMorePadsCb(self, element):
self.log("element:%s" % element.get_name())
gobject.type_register(SingleDecodeBin)