"requested_selection" list might be generated by select-streams event.
And memory of stream-id(s) in select-streams is independent from that of stream-collection.
https://bugzilla.gnome.org/show_bug.cgi?id=775553
When the decodebin state change fails because of an error
message, we might not go through PAUSED->READY. Don't leak
a ref to decodebin pads due to pad blocking in that case.
This is because we return ASYNC going to PAUSED, and if
we fail before reaching PAUSED the only transition we'll
see is READY->NULL.
https://bugzilla.gnome.org/show_bug.cgi?id=775893
The state of urisourcebin (and all elements contained within) can
change at any point in time, including when setting up the typefind
element.
In order to avoid ending up with typefind starting without being fully
connected, lock the state and connect to the 'have-type' signal.
Due to the special nature of adaptivedemux, reconfigure happens
frequently with seek/track-change.
In very exceptional cases, the following sequence is possible:
* EOS event is pushed to queue element and still buffers are queued
* During draining remaining buffers, reconfiguration downstream
happens due to track switch.
* The queue gets a not-linked flow return from downstream
* Because the sinkpad is EOS, the queue registers an
error on the bus, causing the pipeline to fail.
Avoid the sinkpad getting marked EOS in the first place, by using a
custom event in place of EOS.
https://bugzilla.gnome.org/show_bug.cgi?id=777009
When shutting down decodebin2 and parsebin, they set their
output pads to flushing, and there is a very small window
where elements might send a sticky event such as a tag event
(which silently fails due to flushing) and then sends a buffer,
and the buffer will return GST_FLOW_ERROR because it can't
forward sticky events. The element will then send an error
message on the bus. This can also happen when elements send EOS
just as shutdown is happening. Since we're about to destroy all
the elements inside parsebin and decodebin anyway, just discard
error messages from them.
A nicer but more difficult fix for GStreamer 2.0 is to make
all event pushing / handling in core return a GstFlowReturn
like buffers do, so we can report a FLUSHING state cleanly.
When plugging and then exposing a parser, don't fail
if it fails to send sticky events. The most likely
reason is that things were flushed due to the app
immediately doing a seek, but we can't detect flushing
separately to other error conditions without a
gst_pad_send_event_full() core function that returns
a GstFlowReturn.
There are cases when there is no demuxer involved that could do the
buffering, e.g. HLS with raw MP3 or AAC. In this case we want to place
the buffering multiqueue after the parser.
Before this change, we've considered the first element after the
adaptive streaming demuxer as a parser. This is not always true, e.g.
id3demux. Instead we now wait until we actually have a parser (or
decoder).
Fixes playback on such HLS streams.
Playbin3 takes lock when querying duration and handling
stream-collection message. So,to post stream-collection message,
duration query should be dropped when input pad is being unlinked.
https://bugzilla.gnome.org/show_bug.cgi?id=773341
We have to calculate from the segment.stop, not the segment.start, as
playback goes from stop to start. This fix works around another race
condition in streamsynchronizer in my testcase.
See https://bugzilla.gnome.org/show_bug.cgi?id=771479
When connecting a demuxer through a multiqueue ensure to copy sticky
events in order to allow the following factory being properly
checked that it is functional.
https://bugzilla.gnome.org/show_bug.cgi?id=769580
https://github.com/mesonbuild/meson
With contributions from:
Tim-Philipp Müller <tim@centricular.com>
Jussi Pakkanen <jpakkane@gmail.com> (original port)
Highlights of the features provided are:
* Faster builds on Linux (~40-50% faster)
* The ability to build with MSVC on Windows
* Generate Visual Studio project files
* Generate XCode project files
* Much faster builds on Windows (on-par with Linux)
* Seriously fast configure and building on embedded
... and many more. For more details see:
http://blog.nirbheek.in/2016/05/gstreamer-and-meson-new-hope.htmlhttp://blog.nirbheek.in/2016/07/building-and-developing-gstreamer-using.html
Building with Meson should work on both Linux and Windows, but may
need a few more tweaks on other operating systems.
When processing EOS for a pad, send a stream-group-done
for the pad in case downstream is waiting for more
data on this stream before it can process related
streams from the group.
https://bugzilla.gnome.org/show_bug.cgi?id=768995
My collection leak fix 83f30627cd
introduced a crash in this scenario: audiotestsrc ! decodebin3 ! fakesink
The reference handling of collection in decodebin3 wasn't very clear and
my attempt to fix the leak introduced a regression where we went one
reference short in some other scenarios.
Fixing this by:
- Giving a strong reference to DecodebinInput making things clearer
- Fixing get_merged_collection() which was sometimes returning an
existing reference and sometimes a new one.
https://bugzilla.gnome.org/show_bug.cgi?id=769080
The collection owned by GstDecodebin3 has to be unreffed when disposing.
gst_event_new_stream_collection() doesn't consume the collection passed
to it so no need to give it an extra ref.
https://bugzilla.gnome.org/show_bug.cgi?id=768811
MultiQueueSlot owns a ref on the active stream so it should release it
when being freed.
DecodebinInputStream owns ref on the active and pending stream so they
should be dropped when being freed.
https://bugzilla.gnome.org/show_bug.cgi?id=768811
gst_stream_get_caps() returns a reffed caps.
The caps passed to gst_query_set_caps_result() are not transfered.
The caps in gst_parse_pad_stream_start_event() was either acquired
using gst_pad_get_current_caps() which returns a new ref or
explicitly reffed.
https://bugzilla.gnome.org/show_bug.cgi?id=768811
With contributions from Jan Schmidt <jan@centricular.com>
* decodebin3 and playbin3 have the same purpose as the decodebin and
playbin elements, except make usage of more 1.x features and the new
GstStream API. This allows them to be more memory/cpu efficient.
* parsebin is a new element that demuxers/depayloads/parses an incoming
stream and exposes elementary streams. It is used by decodebin3.
It also automatically creates GstStream and GstStreamCollection for
elements that don't natively create them and sends the corresponding
events and messages
* Any application using playbin can use playbin3 by setting the env
variable USE_PLAYBIN3=1 without reconfiguration/recompilation.
We take a ref before removing which was never freeded.
The element is still alive anyway because the group has its own ref as
well.
Fix a leak with the 'test_suburi_error_wrongproto' test.
https://bugzilla.gnome.org/show_bug.cgi?id=766515
When we initialize an element in decodebin, we 1) set it to PAUSED and
push sticky events on its sinkpad to trigger negotiation 2) block its
src pad(s) to detect CAPS events. We can't block before 1) as that
would lead to a deadlock.
It's possible (and common) tho that an element configures its srcpad
during 1) and before 2). Therefore before this change we would
typically block and expose an element's pad only once the element
output its first buffer, triggering sticky events to be resent. One
consequence of this behaviour is that it sometimes broke
renegotiation.
With this change now we consider a pad ready to be exposed when it's
->blocked or has fixed caps (which were set before we could block it).
https://bugzilla.gnome.org/show_bug.cgi?id=765456
If we are configured to use buffering and there is no demuxer in the chain, we
still want a multiqueue, otherwise we will ignore the use-buffering property.
In that case, we will insert a multiqueue after the parser or decoder - not
elsewhere, otherwise we won't have timestamps.
https://bugzilla.gnome.org/show_bug.cgi?id=764948
When blocking the subtitle pad, it's expected that stream-start
is the first event, and that it can precede caps arriving on the
peer pad - in fact the caps can only have arrived on the peer
pad when it was pre-primed with sticky events previously.
Instead, just pass the stream-start and don't block, because
stream-start is sticky anyway.
There's a small window between decodebin choosing a buffering level
to post and another thread choosing a different buffering level
where things can race. Close that window by holding a new lock
that's only for posting buffering messages - like what was done
in multiqueue.
https://bugzilla.gnome.org/show_bug.cgi?id=764020
In check_upstream_seekable function, it returns FALSE value even though
we already declare about the seekable variable. So, This patch return
result of seekable in check_upstream_seekable function.
https://bugzilla.gnome.org/show_bug.cgi?id=763975
Due to transient locked state during autoplugging, some elements might be
ignored by the GstBin::change_state() and might still be running. Which could
then cause pad-added and similar accessing decodebin state that does not exist
anymore, and crash.
https://bugzilla.gnome.org/show_bug.cgi?id=763625
In other places we lock it the other way around, leading to possible
deadlocks. Also this will deadlock if analyze_pad() causes a new element to be
autoplugged that adds new pads on itself when its state is changed.
https://bugzilla.gnome.org/show_bug.cgi?id=763491
This reverts commit 0615794300.
deinterlace was ported at some point in the last 4 years and has better video
format support, and especially better negotiation than avdeinterlace. Having
avdeinterlace but not deinterlace causes various problems in zerocopy
scenarios.
https://bugzilla.gnome.org/show_bug.cgi?id=760553
When getting caps of the decode chain, in get_topology, the caps are being
checked if fixed or not. But get_topology will be called when the decode is
chain is being exposed and hence it will always be fixed. Hence removing the
check for fixed caps. Removing gst_pad_get_current_caps for the chain->pad, as
get_pad_caps will again call the same api.
And get_topology can return NULL value if currently shutting down the
pipeline, which on being passed to create message will result in assertion
error. Check if topology is valid before using it
https://bugzilla.gnome.org/show_bug.cgi?id=755918
analyze_new_pad() can return a new decode chain, which might have a new
GstDecodePad in the end. We should use those two for expose_pad() and not the
original ones that were passed to analyze_new_pad().
This fails when having a demuxer element that has raw pads immediately or
if a decoder with raw caps is after an adaptive demuxer.
https://bugzilla.gnome.org/show_bug.cgi?id=760949
[..] when resetting group start time. In GES, we are usually connected
to the streamsynchronizer on one audio and one video pad.
When seeking the timeline, both nlecompositions often output their flush_start
before any of them has output its flush_stop.
The current code, when receiving the first flush stop was using the
running time of the start of the second composition, which could
be pretty much anything, and means nothing at that point.
This patch is thread-safe, as STREAM_SYNCHRONIZER_LOCK is taken
both when setting flushing and when checking it.
https://bugzilla.gnome.org/show_bug.cgi?id=750013
When blocking input pads, we also need to properly set the appropriate
pending flag.
Without this, when switching stream types after initial configuration
(like going from Audio+Video to Audio+Video+Sub) playsink would never
wait for *all* input streams to be blocked (it would just wait for the
new input pad (text in this case) to be blocked).
Since the reconfiguration might introduce unlinking/relinking of elements,
we need to ensure that *ALL* input streams are blocked.
Failure to do so would result in having some input streams pushing data
to inactive elements (returning GST_FLOW_FLUSHING) or unlinked pads
(returning GST_FLOW_NOT_LINKED).
A later optimization could involve only blocking the input pads that
might be involved in reconfiguration. But better be safe than sorry for
now :)
Elements usually require that all fields on their caps are present
on the fixed caps they receive. Using intersection won't verify it,
resort to using is_subset() checks.
https://bugzilla.gnome.org/show_bug.cgi?id=760477
Those accept caps are actually checking if downstream supports
some particular caps to check if it need to negotiate a different
format. Checking only the next element with accept-caps is not enough
to guarantee that it is supported.
Using a caps query makes it obtain the supported caps for downstream
as a whole instead of only the next element.
The filters' floating references are sinked during set_property() already,
which means that GstBin takes a new reference when adding the filter to it.
Get rid of the additional reference after adding the filter to the bin.
Unconditionally adding the template caps when proxying the caps query will play
havoc with decoders that attempt to choose an output format based on some caps
features. Creating a sink that does not include those caps features and a
decoder/parser/etc that preferentially chooses some specific caps feature when
available, will always return the decoder/parser/etc template caps and choose a
feature that downstream will be unable to support.
Fix by limiting the addition of the template caps to when the result is actually
empty.
https://bugzilla.gnome.org/show_bug.cgi?id=758212
This reverts commit 77dc09c3a9.
It can cause the FLUSH_START/STOP events to go to the sink elements, which
then causes state changes and various other problems. We shouldn't really
flush downstream here, the idea is to do *draining*.
Apart from that the testcase for the original bug here works without this
commit now.
Otherwise we'll remove that element while keeping its buffering message in our
list, and because of that never ever report buffering 100% as that element
will always be at a lower percentage.
This fixes e.g. seeking over Period boundaries in DASH and various other
issues when buffering happens between group switches.
Also use a new mutex for protecting the buffering messages. The object lock is
already used by gst_object_has_as_ancestor() and we need to use it now for
checking if the buffering message sender has the to-be-removed element as
ancestor.
Make sure that any access to the GstDecodeBin's decode_chain
field is protected using the EXPOSE_LOCK. Also add a simple
reference counter to the GstDecodeChain structure so that when
the type_found signal fires it can hold onto the decode chain
even while the EXPOSE_LOCK is not held. This should fix a
race condition if the type_found signal fires right in the
middle of a state change that messes with the same decode
chain.
https://bugzilla.gnome.org/show_bug.cgi?id=755260
Just setting the ghostpad as flushing wasn't enough. It needs to be
consistent on the internal proxypad also, otherwise you end up in
situations where:
* a pending buffer on the target pad triggers the sticky event
propagation
* the default implementation sees that the proxypad is not flushing,
so it tries to push it to the other pad (the actual ghostpad)
* the ghostpad is flushing, so returns FALSE
* the push_event function sees that pushing the event failed...
* ... and pending buffer push returns GST_FLOW_ERROR, instead of
GST_FLOW_FLUSHING
By using gst_pad_set_active(FALSE), we ensure that both the ghostpad
and the proxypad are flushing/deactivated. The situation above will
no longer occur, and a GST_FLOW_FLUSHING will be returned.
This makes sure that they will always get SEEK events, even if we're currently
in the middle of a group switch (i.e. switching to another
representation/bitrate/etc).
https://bugzilla.gnome.org/show_bug.cgi?id=606382
As stated in GST_PAD_PROBE_HANDLED's documentation, we are
supposed to unref the event before returning.
Fixes an event leak in the validate.hls.playback.play_15s.hls_bibbop
validate scenario.
https://bugzilla.gnome.org/show_bug.cgi?id=754459
Send event directly to playsink instead of letting GstBin iterate
over all sink elements. The latter might send the event multiple times
in case the SEEK causes a reconfiguration of the pipeline, as can easily
happen with adaptive streaming demuxers.
What would then happen is that the iterator would be reset, we send the
event again, and on the second time it will fail in the majority of cases
because the pipeline is still being reconfigured
The logic introduced by
[d50b713: decodebin: set the decode pad target before setting elements to PAUSED]
to expose pads would only ever be able to possibly expose one (the last) pad per element.
Make it so that any exposable pads are able to be exposed rather than just the
last pad returned by connect_element.
https://bugzilla.gnome.org/show_bug.cgi?id=742924
In the case of analyzing a demuxer chain, analyze_new_pad may create
a new GstDecodeChain. This was not propagated to the calling function which as
of [d50b713f decodebin: set the decode pad target before setting elements to PAUSED]
is now required to be able to expose the correct pad.
https://bugzilla.gnome.org/show_bug.cgi?id=742924
In case of reconfiguration, text_pad should be re-connected with
stream synchronizer sink pad. Otherwise we'll leave an unlinked pad around if
there always was a streamsynchronizer text pad.
https://bugzilla.gnome.org/show_bug.cgi?id=756804
Otherwise caps and context queries will disappear into nothing and therefore
fail. With autoplug-query now actually working, users (such as playbin) can
proxy these queries to the selected video sink and be able to select an
more appropriate configuration.
https://bugzilla.gnome.org/show_bug.cgi?id=731204
In case sink implements a streamvolume interface, volume element is being got
from the sink. But this is transfer full. So the memory should be freed before
setting it to NULL. This was resulting in major memory leaks
https://bugzilla.gnome.org/show_bug.cgi?id=755867
Casting to gpointer from gulong generates the following warning with
64bit Windows target MinGW:
gstplaybin2.c: In function 'pad_added_cb':
gstplaybin2.c:3476:7: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
(gpointer) group_id_probe_handler);
^
cc1: all warnings being treated as errors
We should cast to guintptr from gulong before we cast to gpointer.
https://bugzilla.gnome.org/show_bug.cgi?id=754755
The default one will just go through the internal elements which might
just be identity when it is in passthrough which will lead to the query
being handled by the downstream sink, ignoring all that playsinkconvertbin
could actually handle and convert.
https://bugzilla.gnome.org/show_bug.cgi?id=754235
It's only relevant for each group, and by storing it in the group
we have locking and everything else like for the other buffering-related
variables. Locking looks a bit fishy still, but it was like that for a long
time already so shouldn't be worse than before.
Overview:
There are some of interleaved streams which has long-term location of audio data.
It mean the audio data is located far away more than multiqueue size.
In this case, because of multiqueue overrun, the pipeline is stopped.
To prevent hanging-like state, the decodebin needs to handle the queue size.
Caused:
The multiqueue size is not enough, the pipeline will stay being stalled status
and decodebin cannot complete to build decode chain.
In this issue file, decodebin did not receive no_more_pads signal or audio data yet.
Steps to Reproduce:
play the high-resolution(4K file) files or some streaming media(push mode).
Actual Results:
There is no audio or subtitle.
We can see only video or infinite loading.
Resolution:
Decodebin detect this problem, and add extra buffer size to multiqueue.
The multiqueue is larger than before, the next data can be pushed the downstream element.
Additional Information:
The max-preroll extra buffer size is set 8MB.
We can use total pre-roll buffer 10MB.
Only first overrun callback can handle multiqueue size.
https://bugzilla.gnome.org/show_bug.cgi?id=733235
When an upstream element wants to flush downstream, we need to take
all chains/groups into consideration.
To that effect, when a FLUSH_START event is seen, after having it
sent downstream we mark all those chains/groups as "drained" (as if
they had seen a EOS event on the endpads).
When a FLUSH_STOP event is received, we check if we need to switch groups.
This is done by checking if there are next groups. If so, we will switch
over to the latest next_group. The actual switch will be done when
that group is blocked.
https://bugzilla.gnome.org/show_bug.cgi?id=606382
When upstream events/queries reach sinkpads of unlinked groups (i.e.
no longer linked to the upstream demuxer), this patch attempts to find
the linked group and forward it upstream of that group.
This is done by adding upstream event/query probes on new group sinkpads
and then:
* Checking if the pad is linked or not (has a peer or not)
* If there is a peer, just let the event/query follow through normally
* If there is no peer, we find a pad to which to proxy it and return
GST_PROBE_HANDLED if it succeeded (allowing the event/query to be properly
returned to the initial called)
Note that this is definitely not thread-safe for the time being
https://bugzilla.gnome.org/show_bug.cgi?id=606382
deadend_details need not be returned when the pad is not a deadend.
Hence checking if res value is TRUE and clearing the string instead of
passing it on
https://bugzilla.gnome.org/show_bug.cgi?id=753088
When switching to a new chain it might be that this new chain
is not yet ready to be exposed so check it before exposing.
Can happen with mpegts that might delay adding pads or pushing data
until it has found the PMT/PAT/PCR and that may take a while depending
on the stream.
It happened frequently with HLS:
http://vevoplaylist-live.hls.adaptive.level3.net/vevo/ch1/appleman.m3u8
If the sink has properties named volume and mute, we have no idea about their
meaning. The streamvolume interface standardizes the meaning.
In the case of osxaudiosink for example, the current volume property has a
range of 0.0 to 1.0, but we need 0.0 to 10.0 or similar. Also osxaudiosink
has no mute property. As such, the volume element should be used here instead.
https://bugzilla.gnome.org/show_bug.cgi?id=752156
We reset the group start time to the running time of the start of the other
streams that are not flushed. This fixes seeking in gapless mode after the
first track has played.
https://bugzilla.gnome.org/show_bug.cgi?id=750013
If suburidecodebin is failed to negotiate (e.g file does not exist)
then free internal suburi variable so that 'current-suburi' property
returns correct status.
https://bugzilla.gnome.org/show_bug.cgi?id=751118
6a2f017bfa changed it to check the subtitle
factory caps if there is a text-sink but we fail to get its sinkpad. What
actually should be done here is to use the factory caps if there is no
text-sink at all.
https://bugzilla.gnome.org/show_bug.cgi?id=750785
There is the GstVideoMultiviewMode enum and the
GstVideoMultiviewFramePacking, which is a subset of the
multiview modes, with the same values as the corresponding
types from the full enum. Do some casts and use the right
times to avoid implicitly using/passing GstVideoMultiviewFramePacking
when a GstVideoMultiviewMode is needed.
Add GstVideoMultiviewFramePacking enum, and the
video-multiview-mode and video-multiview-flags
properties on playbin.
Use a pad probe to replace the multiview information in
video caps sent out from uridecodebin.
This is a part implementation only - for full
correctness, it should also modify caps in caps events,
accept-caps and allocation queries.
https://bugzilla.gnome.org/show_bug.cgi?id=611157
When traversing the color balance element channel list to find the one that
matches with the playsink proxy, the assignation was set to iterator of the
playsink proxy, not the balance element. Thus, the mapping to the values of
the balance element channel was wrong.
This patch fixes the assignation of the color balance element channel, so the
mapping to the channel of the color balance element is fixed.
https://bugzilla.gnome.org/show_bug.cgi?id=750691
when text playbin is not enabled in the beginning, then
video_srcpad_stream_synchronizer gets linked to videochain->sinkpad
and when we try to enable text bin during play, since it is already linked to videochain,
text chain does not get linked properly. Hence unlinking the same
before linking to text chain
https://bugzilla.gnome.org/show_bug.cgi?id=748908
This part of pipeline is:
tee name=t ! visualizationbin ! streamsynchronizer name=s
t. ! s.
streamsynchronizer might block and it could starve the visualization
branch of the pipeline when it is enabled.
The visualization bin has queues internally but the other branch
that links the audiotee directly to the synchronizer is vulnerable
to block. Adding a queue between "t. ! s." fixes deadlocks.
https://bugzilla.gnome.org/show_bug.cgi?id=749676
Upstream might want to use it to properly map timestamps to running/stream
times, if we just override it with 0 synchronization will be just wrong.
For this we remove some old 0.10 code related to segment accumulation, and
remove some more code that is useless now, and accumulate the group start time
(aka segment.base offset) manually now.
https://bugzilla.gnome.org/show_bug.cgi?id=635701
When shutting down the chain, we can get a deadlock when removing
a pad, if that chain was being busy streaming but blocked (eg, while
waiting for a queue to have free space).
https://bugzilla.gnome.org/show_bug.cgi?id=746480
If a new pad is added after playbin has been put to READY/NULL it
should ignore new pads as it is shutting down.
This can happen when the pipeline fails to preroll (is still in READY)
and the user gives up on waiting or an error that doesn't reach
the demuxer occurs (on some event handling) and it will continue to
work and exposing pads while playbin has been put to NULL.
Without this check an input-selector is created and set to PAUSED
state, preventing playbin from properly shutting down in case it
has data blocked inside it.
This fixes a race where the use-buffering property on a multiqueue was
set before the queue depth was changed from it's high preroll limits to
lower playback limits. This resulted in buffering messages being emitted
by the multiqueue in the short window between use-buffering being
set and the queue depth being reset.
https://bugzilla.gnome.org/show_bug.cgi?id=744308
The variables could have changed when the lock was released
to push a gap event. Streamsynchronizer needs to check them
again before going to sleep.
Bonus: fix a comment typo
When we modify a GList (via g_list_delete_link), always reassign the
new head to the original GList. Otherwise we end up with
filtered_errors being corrupt (the head might have been the element
removed)
This function is static, and only ever called with the expose lock
taken. It thus has no reason to take this lock itself.
This was introduced by one of my locking fixes from 741355.
https://bugzilla.gnome.org/show_bug.cgi?id=741355
Check if dbin->decode_chain is NULL before running drain_and_switch_chains()
because if it is, we shouldn't run that function or it will segfault.
CID #1271074
Otherwise if there are multiple parsers we would most likely break negotiation
of the stream-format/alignment wanted by the decoders as parsers generally
support all possible stream-formats and alignments.
If caps on a newly added pad are NULL, analyze_new_pad will try to
acquire the chain lock to add a probe to the pad so the chain can
be built later. This comes from the streaming thread, in response
to headers or other buffers causing this pad to be added, so the
stream lock is taken.
Meanwhile, another thread might be destroying the chain from a
downward state change. This will cause the chain to be freed with
the chain lock taken, and some elements are set to NULL here, which
can include the parser. This causes pad deactivation, which tries
to take the element's pad's stream lock, deadlocking.
Fix this by keeping track of which elements need setting to NULL,
and only do this after the chain lock is released. Only the chain
manipulation needs to be locked, not the elements' state changes.
https://bugzilla.gnome.org/show_bug.cgi?id=741355
There was a deadlock between a thread changing decodebin/demuxer
state from PAUSED to READY, and another thread pushing data
when starting.
From the stack trace at
https://bug741355.bugzilla-attachments.gnome.org/attachment.cgi?id=292471,
I deduce the following is happening, though I did not reproduce the
problem so I'm not sure this patch fixes it.
The streaming thread (thread 2 in that stack trace) takes the demuxer's
sink pad's stream lock in gst_ogg_demux_perform_seek_pull and will
activate a new chain. This ends up causing the expose lock being taken
in _pad_added_cb in decodebin.
Meanwhile, a state changed is triggered on thread 1, which takes the
expose lock in decodebin in gst_decode_bin_change_state, then frees
the previous chain, which ends up calling gst_pad_stop_task on the
demuxer's task, which in turn takes the demuxer's sink pad's stream
lock, deadlocking as both threads are now waiting for each other.
https://bugzilla.gnome.org/show_bug.cgi?id=741355
