Video playback broken with Qt 5.5

Bug #1474695 reported by Timo Jyrinki
8
This bug affects 1 person
Affects Status Importance Assigned to Milestone
Canonical System Image
Fix Released
Medium
Zoltan Balogh
qtvideo-node (Ubuntu)
Fix Released
Critical
Timo Jyrinki

Bug Description

Video playback is broken with Qt 5.5 (tested on mako). Eg sintel trailer just shows a black screen, and no audio. Pure music playback does work elsewhere.

More information at https://wiki.ubuntu.com/Touch/QtTesting

Tags: qt5.5

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Revision history for this message
Timo Jyrinki (timo-jyrinki) wrote :
Revision history for this message
Timo Jyrinki (timo-jyrinki) wrote :

Thumbnailing works however fine, but the video does not play in Media Player.

Changed in qtvideo-node (Ubuntu):
assignee: nobody → Jim Hodapp (jhodapp)
Jim Hodapp (jhodapp)
no longer affects: mediaplayer-app (Ubuntu)
Revision history for this message
Timo Jyrinki (timo-jyrinki) wrote :
Revision history for this message
Timo Jyrinki (timo-jyrinki) wrote :

Videos in YouTube work, and the id used in qtvideo-node is still at the /5.2 it was adapted to during http://bazaar.launchpad.net/~phablet-team/qtvideo-node/trunk/revision/49

Revision history for this message
Jim Hodapp (jhodapp) wrote :

Can you get the log for mediaplayer-app as well? This will have the qtmultimedia/qtubuntu-media debug output.

Revision history for this message
Timo Jyrinki (timo-jyrinki) wrote :

Not much to be seen here. It now eventually crashes, attaching the crash file too.

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Timo Jyrinki (timo-jyrinki) wrote :
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Timo Jyrinki (timo-jyrinki) wrote :

The .crash file is not of much help without debug symbols though.

Revision history for this message
Timo Jyrinki (timo-jyrinki) wrote :

Ok it's possible to gdb -p [pidofmediaplayer-app] to get:

#0 0xb636a580 in QObject::staticMetaObject () from /usr/lib/arm-linux-gnueabihf/libQt5Core.so.5
#1 0xb0711c34 in QDeclarativeVideoRendererBackend::updatePaintNode (this=0x8bd328, oldNode=0xad30a070, data=<optimized out>)
    at qdeclarativevideooutput_render.cpp:319
#2 0xb69f15ce in QQuickWindowPrivate::updateDirtyNode (this=this@entry=0x7bd658, item=item@entry=0x868eb0)
    at items/qquickwindow.cpp:2985
#3 0xb69f1af4 in QQuickWindowPrivate::updateDirtyNodes (this=this@entry=0x7bd658) at items/qquickwindow.cpp:2723
#4 0xb69f1c2c in QQuickWindowPrivate::syncSceneGraph (this=this@entry=0x7bd658) at items/qquickwindow.cpp:341
#5 0xb69d2274 in QSGRenderThread::sync (this=this@entry=0x90bf38, inExpose=inExpose@entry=false)
    at scenegraph/qsgthreadedrenderloop.cpp:512
#6 0xb69d2a64 in QSGRenderThread::syncAndRender (this=this@entry=0x90bf38) at scenegraph/qsgthreadedrenderloop.cpp:558
#7 0xb69d6776 in QSGRenderThread::run (this=0x90bf38) at scenegraph/qsgthreadedrenderloop.cpp:674
#8 0xb60a8106 in QThreadPrivate::start (arg=0x90bf38) at thread/qthread_unix.cpp:331
#9 0xb5df6490 in start_thread () from /lib/arm-linux-gnueabihf/libpthread.so.0

That's probably as far as I can get there, and the trace doesn't show any hints why video playback works for eg thumbnailer + in Youtube but not in media-player - nothing related to qtvideo-node shown for example, and the backtrace does not go further back because of corrupt stack.

Any help welcome.

Revision history for this message
Jim Hodapp (jhodapp) wrote :

Thanks Timo. It looks like this is a regression or change of behavior in how the Qt threaded renderer works. Perhaps it has a new requirement for how a QSGVideoNode needs to be setup. Another thought: we brought QSGVideoNode into qtubuntu-media, maybe the definition used by the threaded renderer loop has changed for Qt 5.5 and we need to update our local copy of it.

Revision history for this message
Timo Jyrinki (timo-jyrinki) wrote :

Right, you mean qtvideo-node. Thanks for reminding about the inclusion of those private headers, they had indeed changed.

With the attached MP video playback works again.

Changed in qtvideo-node (Ubuntu):
assignee: Jim Hodapp (jhodapp) → Timo Jyrinki (timo-jyrinki)
status: New → In Progress
Changed in canonical-devices-system-image:
assignee: nobody → Zoltan Balogh (bzoltan)
importance: Undecided → Critical
milestone: none → backlog
status: New → In Progress
Revision history for this message
Pat McGowan (pat-mcgowan) wrote :

downgrade since we will not move to 5.5 near term

Changed in canonical-devices-system-image:
importance: Critical → Medium
Revision history for this message
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package qtvideo-node - 0.2.1+16.04.20151104-0ubuntu1

---------------
qtvideo-node (0.2.1+16.04.20151104-0ubuntu1) xenial; urgency=medium

  [ CI Train Bot ]
  * New rebuild forced.

  [ Timo Jyrinki ]
  * Port to Qt 5.5 to fix video playback (LP: #1474695) (LP: #1474695)

 -- CI Train Bot <email address hidden> Wed, 04 Nov 2015 08:20:56 +0000

Changed in qtvideo-node (Ubuntu):
status: In Progress → Fix Released
Changed in canonical-devices-system-image:
status: In Progress → Fix Released
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