Remove the getcaps function on the pad and use the CAPS query for
the same effect.
Add PROXY_CAPS to the pad flags. This instructs the default caps event and query
handlers to pass on the CAPS related queries and events. This simplifies a lot
of elements that passtrough caps negotiation.
Make two utility functions to proxy caps queries and aggregate the result. Needs
to use the pad forward function instead later.
Make the _query_peer_ utility functions use the gst_pad_peer_query() function to
make sure the probes are emited properly.
No one but filesrc used that API. Should probably be replaced by
requiring an "uri" property instead, and then objects can do a
notify on that. Also removed interface structure padding, it's
not needed.
when we are flushing, don't store the event on the pad but simply return FALSE.
Don't deactivate the srcpad, we need it to be active in order to push the
caps. Downstream can change the scheduling mode of an active pad.
There's no code that uses it other than multiqueue, so make it private
to multiqueue for now. That way we can also do optimisations that
require API/ABI breaks. If anyone ever wants to use it, we can still
make it public again.
_set_caps only gets called when the buffer is actually pushed, so there
is a reasonably big window between when the initial caps are retrieved
and when the caps are set on our src pad. So we can't assume the not
having negotiated caps on our src pad means _get_caps still has to be
called.
Instead simply always suggest the new caps on buffer_alloc.
Add a vmethod to handle the pad query.
Install a default handler for the pad query.
Add a vmethod to setup the allocation properties.
Use the new query function in filesink
Implement the sink event handling like the src event handler. Make the default
implementation parse and forward the event. This makes it possible to actually
return an error value from the event handler.
Remove the requirement to have to return a ref to the input buffer when in
passthrough mode. This saves a few ref/unref cycles and fixes another 0.11
FIXME.
Remove the caps and size from the prepare_output_buffer function. with
bufferpools and capsnego done differently, we don't need this in most cases and
if we do, we can simply use the transform_size function and get the caps from
the srcpad.
Add an index to gst_buffer_take_memory() so that we can also insert memory at a
certain offset. This is mostly interesting to prepend a header memory block to
the buffer.
Make a new method to allocate a buffer + memory that takes the allocator and the
alignment as parameters. Provide a macro for the old method but prefer to use
the new method to encourage plugins to negotiate the allocator properly.
Add a new fill virtual method to basesrc. The purpose of this method is to fill
a provided buffer with data.
Add a default implementation of the create method that allocates a buffer and
calls the fill method on it. This would allow the base class to implement
bufferpool and allocator negotiation on behalf of the subclasses.
Fix the blocksize property.
Make filesrc use the new fill method.
Always forward all events in the default handler. Previously it used to not
forward caps events by default. It makes more sense to forward the caps events,
if the element is interested in the caps, it will implement an event handler to
retrieve the caps and then it can decide to forward or not. If the element has
no event handler, it probably just doesn't care about caps and it probably is
also not going to modify the data in a way that needs a caps change.
See #651514 for details. It's apparently impossible to write code
that avoids both type punning warnings with old g_atomic headers and
assertions in the new. Thus, macros and a version check.
When releasing the request pad, first remove it from the element and then
deactivate it. If we do it the other way around, a gst_pad_push on the element
might return wrong-state before we had a chance to detect the removed pad in the
chain function.
This makes sure that SEEK events are sent to all upstream elements, which is
required if different streams are completely distinct pipeline parts. Also this
allows QoS to be done on deselected streams, flushes to be handled correctly,
etc.
The switch action signal with the stop and start running times
is not necessary anymore. Closing of segments is not necessary
and adjusting the start running time of a segment can later be
done with new GstPad API.
This reverts commit cf4fbc005c.
This change did not improve the situation for bindings because
queries are usually created, then directly passed to a function
and not stored elsewhere, and the writability problem with
miniobjects usually happens with buffers or caps instead.
Improve GstSegment, rename some fields. The idea is to have the GstSegment
structure represent the timing structure of the buffers as they are generated by
the source or demuxer element.
gst_segment_set_seek() -> gst_segment_do_seek()
Rename the NEWSEGMENT event to SEGMENT.
Make parsing of the SEGMENT event into a GstSegment structure.
Pass a GstSegment structure when making a new SEGMENT event. This allows us to
pass the timing info directly to the next element. No accumulation is needed in
the receiving element, all the info is inside the element.
Remove gst_segment_set_newsegment(): This function as used to accumulate
segments received from upstream, which is now not needed anymore because the
segment event contains the complete timing information.
This reverts commit 9ef1346b1f.
Way to much for one commit and I'm not sure we want to get rid of the pad caps
just like that. It's nice to have the buffer and its type in onw nice bundle
without having to drag the complete context with it.
Remove pad_alloc and all references. This can now be done more efficiently and
more flexible with the ALLOCATION query and the bufferpool objects. There is no
reverse negotiation yet but that will be done with an event later.
1) We need to lock and get a strong ref to the parent, if still there.
2) If it has gone away, we need to handle that gracefully.
This is necessary in order to safely modify a running pipeline. Has been
observed when a streaming thread is doing a buffer_alloc() while an
application thread sends an event on a pad further downstream, and from
within a pad probe (holding STREAM_LOCK) carries out the pipeline plumbing
while the streaming thread has its buffer_alloc() in progress.
Remove the android/ top dir
Fixe the Makefile.am to be androgenized
To build gstreamer for android we are now using androgenizer which generates the needed Android.mk files.
Androgenizer can be found here: http://git.collabora.co.uk/?p=user/derek/androgenizer.git
Use the string provided by the caller for the sinkpad name
if possible. Note that all sanity checking for this name
is already done in GstElement.
Fixes Bug #645931
It can happen that the currently active pad got the EOS event
before it was activated and the previously active pad got the
EOS event after it was deactivated. In that case we have to
send the EOS event from an inactive pad downstream.
This makes sure that during switches at no point in time all pads
have returned not-linked, which can happen when playing an audio-only
file with playbin2 and switching between the streams for example.
Fixes bug #644935.
Passing e.g. location=foo would lead to warnings because g_filename_to_uri()
wants an absolute file path and returns NULL otherwise. Use brand-new
gst_filename_to_uri() instead, which will try harder to create a proper
URI for us.
Also add unit test.
... which could lead to a premature eos being reported downstream,
rather than a successful partial read which would result when
performed directly on e.g. basesrc.
Once we switch to normal mode, we're not typefinding anymore and thus the caps
will not change. Therefore can avoid the object lock in the data-flow path.
The locking was added in order to fix bug #608877.
Adds getcaps/setcaps to output-selector and adds a property
to select which type of negotiation should be done.
The available modes are:
* none: no negotiation (current behavior), getcaps return ANY and
setcaps aren't set on any of the peers
* all: use all pads (default), getcaps returns the intersection of
peer pads and setcaps is set on all peers
* active: getcaps and setcaps are proxied to the active pad
https://bugzilla.gnome.org/show_bug.cgi?id=638381
This patch makes outputselector take an extra ref when pushing
the last_buffer to avoid it losing it during the switch function.
This makes resend-latest properly work if the active-pad is changed
during the switch function buffer pushing (on a pad probe, for example).
https://bugzilla.gnome.org/show_bug.cgi?id=629917
This patch makes output-selector always recheck if there's a
pending pad switch after pushing a buffer, preventing that
it pushes a buffer on the 'wrong' pad.
https://bugzilla.gnome.org/show_bug.cgi?id=629917
Using the end time makes it impossible to replace buffers, which is
a big problem for subtitles that could have very long durations.
Merged from gst-plugins-base, 27034be461.
There's not much point in using GST_DEBUG_FUNCPTR with GObject
virtual functions such as get_property, set_propery, finalize and
dispose, since they'll never be used by anyone anyway. Saves a
few bytes and possibly a sixteenth of a polar bear.
Merged from gst-plugins-base, 6f4c1ac583.
Replaced with "GStreamer maintainers
<gstreamer-devel@lists.sourceforge.net>" or just removed,
depending on the number of other authors.
Merged from gst-plugins-base, 0e9bc5125a.
Set the output caps on the srcpad before pushing the buffer because else core
will do a rather expensive check to see if we can actually accept those caps on
the srcpad.
Merged from gst-plugins-base, bdfb4b46d7.
Install a custom acceptcaps function instead of using the default expensive
check. We accept whatever downstream accepts so we pass along the acceptcaps
call to the downstream peer.
Merged from gst-plugins-base, 5b72f2adf9.
We should do the pad_alloc for the pending pad if any, as we will switch to that
pad on next _chain() call. Also do a fallback alloc, if there is no output yet to
not fail state transitions in dynamic pipelines.
When a segment event is received on the active pad, forward it downstream
immediately instead of deferring it until the next data buffer arrives. This
fixes problems with segment updates never being sent downstream, like those
needed for sparse streams, or for closing previously opened segments.
This fixes playback of DVD menus with a still video frame and an audio track,
for example.
Fixes: #577843
No short-desc as we have them in the element details.
Also keep things (Makefile.am and sections.txt) sorted.
Reword ambigous returns. No text after since please.
Original commit message from CVS:
* plugins/elements/gstinputselector.c:
Ensure we emit notify::active-pad when auto-selecting a pad
due to it having activity and us not having an existing active
pad. Fixes#563147
Original commit message from CVS:
* plugins/elements/gstinputselector.c: (gst_input_selector_event),
(gst_input_selector_query):
Gracefully handle the cases when we dont' have otherpad.
Fixes#556430
Original commit message from CVS:
* plugins/elements/gstinputselector.c: (gst_selector_pad_reset),
(gst_input_selector_reset), (gst_input_selector_change_state):
Reset the selector state when going to READY.
Original commit message from CVS:
* plugins/elements/gstinputselector.c: (gst_input_selector_init),
(gst_input_selector_event), (gst_input_selector_query):
Reuse the get_linked_pads for both source and sinkpads because they are
the same.
Implement a custum event handler and get the internally linked pad
directly instead of relying on the default (slower) implementation.
Original commit message from CVS:
* plugins/elements/gstinputselector.c: (gst_input_selector_init),
(gst_input_selector_query):
Implement the LATENCY query in a better way by taking the latency of all
sinkpads and taking the min/max instead of just taking a random pad.
Original commit message from CVS:
* plugins/elements/gstinputselector.c: (gst_selector_pad_bufferalloc),
(gst_selector_pad_chain), (gst_input_selector_getcaps),
(gst_input_selector_activate_sinkpad):
Move the select-all logic into the activation of the currently selected
pad. We want to remember the last pad with activity in select-all mode.
Fix the getcaps function, we can produce the union of the upstream caps
in select-all mode, not the intersection like proxy_getcaps() does.
Original commit message from CVS:
* plugins/elements/gstoutputselector.c:
* tests/icles/output-selector-test.c:
Use BOILERPLATE macro and update test to the latest api changes.
Original commit message from CVS:
* ext/dc1394/gstdc1394.c:
* ext/ivorbis/vorbisdec.c:
* ext/jack/gstjackaudiosink.c:
* ext/metadata/gstmetadatademux.c:
* ext/mythtv/gstmythtvsrc.c:
* ext/theora/theoradec.c:
* gst-libs/gst/app/gstappsink.c:
* gst/bayer/gstbayer2rgb.c:
* gst/deinterlace/gstdeinterlace.c:
* gst/rawparse/gstaudioparse.c:
* gst/rawparse/gstvideoparse.c:
* gst/rtpmanager/gstrtpbin.c:
* gst/rtpmanager/gstrtpclient.c:
* gst/rtpmanager/gstrtpjitterbuffer.c:
* gst/rtpmanager/gstrtpptdemux.c:
* gst/rtpmanager/gstrtpsession.c:
* gst/rtpmanager/gstrtpssrcdemux.c:
* plugins/elements/gstinputselector.c:
* plugins/elements/gstoutputselector.c:
* gst/videosignal/gstvideoanalyse.c:
* gst/videosignal/gstvideodetect.c:
* gst/videosignal/gstvideomark.c:
* sys/oss4/oss4-mixer.c:
* sys/oss4/oss4-sink.c:
* sys/oss4/oss4-source.c:
Do not use short_description in section docs for elements. We extract
them from element details and there will be warnings if they differ.
Also fixing up the ChangeLog order.
Original commit message from CVS:
* plugins/elements/gstinputselector.c:
(gst_input_selector_set_active_pad), (gst_input_selector_switch):
Do g_object_notify() only when not holding the lock to get the property
because otherwise we run into a deadlock with the deep-notify handlers
that are possibly installed.
Original commit message from CVS:
* plugins/elements/gstinputselector.c: (gst_selector_pad_class_init),
(gst_selector_pad_event), (gst_selector_pad_bufferalloc),
(gst_selector_pad_chain), (gst_input_selector_set_active_pad):
Release the selector lock when pad alloc happens on a non selected pad.
Original commit message from CVS:
* plugins/elements/gstinputselector.c: (gst_selector_pad_class_init),
(gst_selector_pad_init), (gst_selector_pad_set_property),
(gst_selector_pad_get_property), (gst_selector_pad_event),
(gst_selector_pad_bufferalloc), (gst_selector_pad_chain),
(gst_input_selector_set_active_pad):
Add pad property to configure behaviour of the unselected pad, it can
return OK or NOT_LINKED, based on the use case.
Original commit message from CVS:
* plugins/elements/gstinputselector.c:
(gst_selector_pad_get_running_time), (gst_selector_pad_reset),
(gst_selector_pad_event), (gst_selector_pad_bufferalloc),
(gst_input_selector_wait), (gst_selector_pad_chain),
(gst_input_selector_class_init), (gst_input_selector_init),
(gst_input_selector_dispose), (gst_segment_set_start),
(gst_input_selector_set_active_pad),
(gst_input_selector_set_property),
(gst_input_selector_get_property),
(gst_input_selector_get_linked_pad),
(gst_input_selector_is_active_sinkpad),
(gst_input_selector_activate_sinkpad),
(gst_input_selector_request_new_pad),
(gst_input_selector_release_pad),
(gst_input_selector_change_state), (gst_input_selector_block),
(gst_input_selector_switch):
* plugins/elements/gstinputselector.h:
Figure out the locking a bit more.
Mark buffers with discont after switching.
Fix initial segment forwarding, make sure to only forward one segment
regardless of what the sequence of buffers/segments is. See #522203.
Improve flushing when blocked.
Return NOT_LINKED when a stream is not selected.
Not API change for the switch signal in the docs.
Fix start/time/accum values of the new segment.
Correctly unlock and flush a blocking selector when going to READY.
Original commit message from CVS:
* plugins/elements/gstinputselector.c: (gst_selector_pad_event),
(gst_selector_pad_bufferalloc), (gst_selector_pad_chain),
(gst_input_selector_class_init),
(gst_input_selector_set_active_pad),
(gst_input_selector_set_property),
(gst_input_selector_push_pending_stop):
Add lots of debugging.
Fix time member in the newsegment event.
Original commit message from CVS:
* plugins/elements/gstinputselector.c: (gst_selector_pad_class_init),
(gst_selector_pad_finalize), (gst_selector_pad_get_property),
(gst_selector_pad_event), (gst_input_selector_class_init),
(gst_input_selector_init), (gst_input_selector_set_active_pad),
(gst_input_selector_set_property),
(gst_input_selector_get_property),
(gst_input_selector_request_new_pad),
(gst_input_selector_release_pad),
(gst_input_selector_push_pending_stop),
(gst_input_selector_switch):
* plugins/elements/gstinputselector.h:
Various cleanups.
Added tags to the pads.
Select active pad based on the pad object instead of its name.
Fix refcount in set_active_pad.
Add property to get the number of pads.
* plugins/elements/gstoutputselector.c:
(gst_output_selector_class_init),
(gst_output_selector_set_property),
(gst_output_selector_get_property):
Various cleanups.
Select the active pad based on the pad object instead of its name.
Fix locking when setting the active pad.
* plugins/elements/gstselector-marshal.list:
* tests/check/elements/selector.c: (cleanup_pad),
(selector_set_active_pad), (run_input_selector_buffer_count):
Fixes for pad instead of padname for pad selection.
Original commit message from CVS:
* plugins/elements/gstinputselector.c:
* plugins/elements/gstinputselector.h:
Added "select-all" property to make it work like aggregator in 0.8.
* plugins/elements/gstoutputselector.c:
Fix resend-latest behavoiur.
* tests/check/Makefile.am:
* tests/check/elements/.cvsignore:
* tests/check/elements/selector.c:
Add unit tests for selector.
Original commit message from CVS:
* gst/multifile/gstmultifilesink.c:
Add a fixme comment.
* plugins/elements/gstoutputselector.c:
Fix same leak as in input-selector.
* tests/icles/output-selector-test.c:
Improve the test.
Original commit message from CVS:
* plugins/elements/gstinputselector.c: (gst_selector_pad_event):
Don't leak event on pads that are not linked. Fixes#512826.
Other than saving an immense amount of 4 bytes of memory this
prevents clang from complaining and keeps the ring buffer state
in a single variable instead of two.
If downstream is operating in pull mode, short-circuit any pulls beyond
the end of the file and return FLOW_UNEXPECTED immediately instead of
sending a seek beyond the end of the file upstream, since this might
confuse upstream elements (and/or http servers, for example). Fixes
playback of apple trailers in totem and youtube/html5 clips in
WebkitGTK+.
https://bugzilla.gnome.org/show_bug.cgi?id=632977
Make sure property names passed to g_object_notify() are in the canonical form
(ie. "last-message" not "last_message"), so that g_param_spec_pool_lookup()
doesn't have to do strdup/canonicalize/free for every single notify call.
This only applies when building against older GLib versions (< 2.26).
Use more efficient g_object_notify_by_pspec() if we're compiling against
GLib >= 2.26, and also remove work-around for g_object_notify() thread-
safety issues with older GLib versions if it's not needed any more.
Use more efficient g_object_notify_by_pspec() if we're compiling against
GLib >= 2.26, and also remove work-around for g_object_notify() thread-
safety issues with older GLib versions if it's not needed any more.
Instead return after every iteration, which makes sure that the
stream lock is released for a short time after every iteration,
task state changes are checked, etc and this allows the task
to be stopped properly.
- Set reading_pos correctly in _create_read ()
- Seek to data if it is further than QUEUE_MAX_BYTES (queue) -
cur_level.bytes away. This should avoid a situation where the ring
buffer is full but the data offset from which we shall read is not in
the ring buffer.
- Only update the max_reading_pos to a lower value to protect data when
necessary
- Always signal an ADD in _locked_enqueue () so that an EOS unlocks the
reader
- More useful debug output
update_buffering () needs to be called every time we write to the ring
buffer so that applications don't get stuck waiting for a 100% buffered
message while queue2 is waiting for space
_create_write () must only be called for temp file/ring buffer cases
Cached data could have been overwritten so it is now protected until
it is read. Similarly data was overread as _have_data () was always
looking for the originally requested data even if part of it had been
read already.
Use cur_level.bytes to see how much space is free in the ringbuffer.
Simplyfy the write function, avoid taking subbuffers, move waiting for free
space in one spot, use simply counter to write data of a buffer.
- make _get_range () emit the del signal once a buffer has been read
- use do {} while (); for wait code as queue is locked and no data could
have been read in the mean time so it makes no sense to check before
waiting
- make _is_filled () more robust
Current range was being updated in the thread performing seek, but as
no locks were kept for a short section, data flow could resume before
current range updated, so data for the new range would be accepted as
from the previous range.
Rather, range should be updated in serialized manner based on
newsegment event.
Don't override the default get_times vmethod so that we can use the sync
property.
Set the default sync property to FALSE. It used to be set to TRUE but because
the get_times was NULL, it always behaved like FALSE.
Fixes#621530
Implement a custom acceptcaps function. We can simply check if there is an
intersection with the new caps. This makes the accept caps function much faster.
See #621190
When in download mode and we need to provide data for an offset that we don't
have, also perform a seek to the requested location when we are EOS. The reason
why we shouldn't wait for more data is because after EOS, there simply will be
no more data and we end up waiting forever.
Fixes#620500
Parse a size=value from the query string to specify a size. This is interesting
when reading from a file descriptor that actually has a size (and is not
stat-able, such as the socket of an http connection)
Maintain a separate variable to control src and sink flowreturn values so that
we can unlock the src part without shutting down the sink part.
Add flushing for upstream pull based elements that unblocks our getrange
function. This implements seeking when blocking for more data.
Add some arbitrary threshold before attempting a seek. Add a FIXME for this
because we need to find a sensible threshold based on the input rate.
When in download mode and the requested offset is too far away, attempt to do a
seek request to fetch the data.
Keep track of all downloaded parts and merge ranges when needed.
Fixes#600877
This changes some APIs in compatible ways:
- Some functions now take "const char *" arguments, not "char *"
- Some structs now have "conts char *" members, not "char *"
The changes may cause warnings when compiling with the right warning
flags. You've been warned.
Also adds -Wwrite-strings as a warning flag in configure.ac.
https://bugzilla.gnome.org/show_bug.cgi?id=611692
_create() is a pad function set by ourselves, therefore we're sure basesrc
is a GstFileSrc.
Speeds up _create() by 17% and the total call by 8% (instruction calls measurements
done with valgrind).
Fixes#610246
Initialize new_fd with DEFAULT_FD and fd with -1. Setting the property will set
new_fd and in _update_fd() we cehck fd against -1. Also add a coment about the
warning we get in the log from gst_poll_remove_fd(). We could get rid of the
warning if we want by tracking if fd has been added to fdset.
Typefind might mess up pads modes (pull/push) if a
downstream element is plugged and its pads activated
in 'step 2' of typefind pads activation.
This happens because the following steps don't check
if we already emitted typefound due to upstream setting
caps on buffers being pulled in the typefind helpers.
Avoid that by checking if typefound is already emmited.
Fixes#608036
When a downstream element returns GST_FLOW_UNEXPECTED we want to:
* let the dataqueue task running
* forward the flow return upstream.
This allows upstream elements to push EOS, and have that EOS event come
downstream.
Fixes#609274
When we receive an UNEXPECTED flowreturn from downstream, we must not shutdown
the pushing thread because upstream will at some point push an EOS that we still
need to push further downstream.
To achieve this, convert the UNEXPECTED return value to OK. Add a fixme so that
we implement the right logic to propagate the flowreturn upstream at some point.
Also clean up the unit test a little.
Fixes#608136
Add an option to automatically remove the temp file (TRUE by default). This
should make it possible for the application to keep the temp file by other means
than hardlinking or holding an fd open.
Fixes#607739
For the reason outlined at the beginning of gst_private.h (inline
functions in glib may need the g_log_domain variable). Also include
gst_private.h before using any G_OS_* defines, esp. in plugin loader.
Protect the ->removed field with the object lock as well. Take the DYN lock
earlier so that we can mark the pad removed and avoid a race in pad_alloc.
Fixes#606435
gstfilesink.c:399: error: format ‘%d’ expects type ‘int’, but argument 8 has type ‘size_t’
gstfilesink.c:399: error: format ‘%d’ expects type ‘int’, but argument 9 has type ‘gsize’
gstfilesrc.c:588: error: format ‘%08llx’ expects type ‘long long unsigned int’, but argument 8 has type ‘off_t’
It is not easy to setup a tee on the fly, thus apps need to add them always if
they might need them. This changes the code so, that if only one src-pad is
active, we push buffers directly. In the normal code path all buffers are pushed
with an extra ref, that forces followup inplace elements to copy the data.
Cast the variable to gint to conform to the printf format used.
It is casted rather than changing the format because the
message is created with a cast to gint too.
queue2 would crash when using small buffer sizes because
it would overflow when calculating the percentage, resulting
in the buffering GstMessage not being created and trying to be
used. This patch uses a gint64 instead of a gint to do the
percentage math, making it harder to overflow.
Using the current fill level of the queue, and the average input
rate, we can determine how long it will take to finish downloading
the whole stream to the temporary file.
Fixes#600726
There's not much point in using GST_DEBUG_FUNCPTR with GObject
virtual functions such as get_property, set_propery, finalize and
dispose, since they'll never be used by anyone anyway. Saves a
few bytes and possibly a tenth of a polar bear.
Add support for buffering mode where we post BUFFERING messages based on the
level of the queues. It currently operates on the first queue that goes over or
under the high/low thresholds.
In buffering mode we want to ignore the max visible items to decide when the
queue is filled. Instead, we only look at the number of bytes and/or time in the
queue.
Don't shadow the sq argument in the underrun_cb function but use
a different variable name to iterate the other queues.
Use the same variable name in the overrun_cb function.
Split gst_queue_locked_enqueue() into variant for buffer and event to get rid of
the if() and make the code more readable (constant boolean parameters are never
nice). Removes the if (item) checks as we dereference the pointer before anyway.
Also apply the same idea of reusing the previous knowledge in
gst_queue_locked_dequeue to remove more type checks.
We know earlier on in the code whether we're handling an event or a buffer,
just pass that information through.
This commit and the previous commit reduce instruction fetch:
* when pushing buffer (_chain) by 10%
* when popping buffer (_loop) by 3%
The task will always exist as long as its owner (i.e. the pad) and that
owner's owner (i.e. multiqueue) exist.
Reduces the number of instruction fetches by 36%.
We know whether we have a buffer or an event, use that instead of going
trough the expensive GLib typecheck.
The overall instruction fetch reduction introduced by this commit and the
2 previous commits:
* receiving a buffer (_chain) by 20%
* popping a buffer (_loop) by 14%
Numbers acquired through callgrind passing 100000 buffers through queue.
