Cannot find -lQt5Multimedia?!

shantia_73

Hi everyone
i dont know what i installed or removed that this error came up!
i even removed qtcreator and install it again, but still not works.
please someone help me, its important and i dont know what to do.

had another question too.
i used QGraphicsVideoItem and QGraphicsScene to show videos in my app,
some videos opens, but some of them not.
it not based on the size of videos, i tested it and all the gstreamer packages installed on my os.
since i cant open my app with qt right now, i cant put here the error!
so if you know anything about this too, please help
thanks a lot
Ubuntu 14.04 x64

andreyc

I would recommend to install Qt from qt-project.org
It comes with all libraries and qtcreator.
Qt uses gstreamer0.10 Ubuntu-14.04 does not have gstreamer0.10 by default you need to install separately.
If you need to find out why gstreamer does not work run your app with GST_DEBUG=N where N is a verbosity level. I would start from N = 3. See "here":http://gstreamer.freedesktop.org/data/doc/gstreamer/head/manual/html/section-checklist-debug.html for more info.

shantia_73

[quote author="andreyc" date="1414598450"]1. I would recommend to install Qt from qt-project.org
It comes with all libraries and qtcreator.

Qt uses gstreamer0.10 Ubuntu-14.04 does not have gstreamer0.10 by default you need to install separately.
If you need to find out why gstreamer does not work run your app with GST_DEBUG=N where N is a verbosity level. I would start from N = 3. See "here":http://gstreamer.freedesktop.org/data/doc/gstreamer/head/manual/html/section-checklist-debug.html for more info.
[/quote]
thanks
ill try 2. when the application fixed
about the 1. , i downloaded qt-opensource-linux-x64-5.3.2.run and installed it. so i think it must has the libraries!
if you meant something else, please say more
thanks again

andreyc

Yes, I meant exactly that.
Do you have @QT += multimedia multimediawidgets@ in .pro file?
And just for checking do you have
@ Qt5.4.0/5.4/gcc_64/lib/libQt5Multimedia*@

shantia_73

yes, i add it to my project.
about the second one, i have

@libQt5Multimedia.so@

and

@libQt5Multimedia.la@

and some others.
but i have not

@libQt5Multimedia@

specifically. and of course its 5.3.2 for me.(just saying)

andreyc

Have you tried to open and build multimedia examples from Qt?

For example
@
$ cd ~/Qt5.3.2/Examples/Qt-5.3/multimediawidgets
$ mkdir build-videographicsitem
$ ~/Qt5.3.2/5.3/gcc_64/bin/qmake ../videographicsitem/
$ make
..... compilation without any errors and warnings
$ ./videographicsitem
Warning: "No decoder available for type 'video/x-ms-asf'."
Error: "Your GStreamer installation is missing a plug-in."
..... Looks like I have not install all necessary gstreamer0.10 plugins
@

Do you get the same error as in your project?

shantia_73

after make i get this exact error:

@g++ -Wl,-O1 -Wl,-rpath,/home/elshen/Qt5.3.2/5.3/gcc_64 -Wl,-rpath,/home/elshen/Qt5.3.2/5.3/gcc_64/lib -Wl,-rpath-link,/home/elshen/Qt5.3.2/5.3/gcc_64/lib -o videographicsitem main.o videoplayer.o moc_videoplayer.o -L/home/elshen/Qt5.3.2/5.3/gcc_64/lib -lQt5MultimediaWidgets -lQt5Multimedia -lQt5Widgets -lQt5Network -lQt5Gui -lQt5Core -lGL -lpthread
/usr/bin/ld: cannot open output file videographicsitem: Is a directory
collect2: error: ld returned 1 exit status
make: *** [videographicsitem] Error 1@

whats now? whats the problem?

andreyc

Oops. I forgot to put "cd build-videographicsitem" in the steps above.

Here is a correct set of steps
@
$ cd ~/Qt5.3.2/Examples/Qt-5.3/multimediawidgets
$ mkdir build-videographicsitem
$ cd build-videographicsitem
$ ~/Qt5.3.2/5.3/gcc_64/bin/qmake ../videographicsitem/
$ make
..... compilation without any errors and warnings
$ ./videographicsitem
@

shantia_73

ok, now it works :D
the application opens and
this is the output after opening a video:

@(gst-plugin-scanner:32745): GStreamer-WARNING **: Failed to load plugin '/usr/lib/gstreamer-0.10/libgstsimsyn.so': /usr/lib/gstreamer-0.10/libgstsimsyn.so: undefined symbol: gst_controller_sync_values

(gst-plugin-scanner:32745): GStreamer-WARNING **: Failed to load plugin '/usr/lib/gstreamer-0.10/libgstaudiodelay.so': /usr/lib/gstreamer-0.10/libgstaudiodelay.so: undefined symbol: gst_base_transform_set_gap_aware

(gst-plugin-scanner:32745): GStreamer-WARNING **: Failed to load plugin '/usr/lib/gstreamer-0.10/libgstbml.so': /usr/lib/gstreamer-0.10/libgstbml.so: undefined symbol: gst_base_src_set_format

(videographicsitem:32737): GStreamer-CRITICAL **: gst_pad_link_full: assertion 'GST_IS_PAD (sinkpad)' failed
Error: "GStreamer encountered a general stream error."@

shantia_73

Ok, i removed Qt cache from /home today and now it works correctly.
thanks for your helps.

now the gstreamer problem,
i opened the file that you said(videographicitem)
like i said before, it can play some of videos, but cant play some of them.
the error is:

@(videographicsitem:24715): GStreamer-CRITICAL **: gst_pad_link_full: assertion 'GST_IS_PAD (sinkpad)' failed
Error: "GStreamer encountered a general stream error."@

whats the problem? what i have to do?

i actually find out why the cache was broken.
i open qtcreator from /usr/bin/qtcreator.
in that address there is no example or libraries or anything for qt
and because of that, nothing works.
but after cleaning cache and run qt from ~/Qt5.3.2/Tools/QtCreator/bin/qtcreator
all the examples and libraries work correctly. so why is that?!

shantia_73

i should add this to the preview post that:
i used QGraphicVideoItem and with that i had problem.
but then, i used VideoWidget and its play all the videos (though the error shows, even now!)
but i want to use QGraphicTextItem and cant use it with VideoWidget.
so, what can i do?