I have been trying to install gstreamer on my ubuntu 18.04 and to integrate it into a Qt 5.14.1 project. (Quick heads-up: I am not a pro in things Qt and Linux.)
These are the installation steps I followed in order to install gstreamer:
git clone git://anongit.freedesktop.org/gstreamer/qt-gstreamer
cd qt-gstreamer
mkdir build && cd build
cmake QtGstreamer
cmake .. -DCMAKE_INSTALL_PREFIX=/usr -DCMAKE_INSTALL_LIBDIR=lib/$(dpkg-architecture -qDEB_HOST_MULTIARCH) -DCMAKE_INSTALL_INCLUDEDIR=include -DQT_VERSION=5 -DCMAKE_BUILD_TYPE=Release -DCMAKE_CXX_FLAGS=-std=c++11
make -j6 && sudo make install
Which installed a bunch of files under /usr/lib/x86_64-linux-gnu/ and /usr/include/Qt5GStreamer/.
I extended the PKGCONFIG in the .pro file like so:
PKGCONFIG += gstreamer-1.0 gstreamer-app-1.0 gstreamer-video-1.0
PKGCONFIG += Qt5GLib-2.0 Qt5GStreamer-1.0 Qt5GStreamerQuick-1.0 Qt5GStreamerUtils-1.0
In my QML file I try to import it like so:
import QtGStreamer 1.0
Which results in an error.
QML module not found. (QtGSteamer)
I would really appreciate on this matter.
Looks like the module is not found in mldule search path. Did you update pro file as described in Build system integration|qmake?
Did you check if this module exists on file system?
Related
I am currently using Ubuntu 14.04 LTS.
How can I statically build Qt 4.8.5 -
https://download.qt.io/archive/qt/4.8/4.8.5/qt-everywhere-opensource-src-4.8.5.tar.gz
such that when I cmake OpenCV 2.4.13 -
https://github.com/opencv/opencv/archive/2.4.13.zip
it correctly identifies the location of Qt4 ?
When I cmake OpenCV after I have installed Qt4 in /usr/local/qt4-static/, the find_package(Qt4 REQUIRED QtCore QtGui QtTest) function call within opencv-2.4.13/cmake/OpenCVFindLibsGUI.cmake fails because it cannot find qmake. Also, upon running the qmake -query in the terminal, Ubuntu says that qmake is not installed, when it clearly in /usr/local/qt4-static/.
How should I go about this so OpenCV cmake correctly recognizes Qt4 ?
Build Qt
Extract the source-code and run ./configure && make and then sudo make install. It should create all necessary configuration to run qmake in any folder (system-wide).
Additional: create a symlink/export (use only if make install did not work for you)
You need to promote qmake to $PATH or create a symlink, but this is usually done when you run sudo make install after make in the Qt source-folder.
root:/home# echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:
Symlink (permanently)
ln -s /path/to/qmake /usr/sbin/qmake
or
export (temporary)
export PATH=$PATH:/folder/of/qmake
Afterwards qmake -v is working whereever you are
root:/tmp qmake -v
QMake version 3.1
Using Qt version 5.10.1 in /usr/local/Qt-5.10.1/lib
If your project still cannot determine the location of Qt, read the pro/pri/cmake file to understand how it looks for the path.
I'm trying to use the QtContacts module. I'm using ubuntu artful and qt 5.10
I've tried this:
sudo apt-get install qml-module-qtcontacts
and this:
sudo apt-get install qtdeclarative5-qtcontacts-plugin
I put in the .pro file: QT += androidextras contacts, but I get the message: Project ERROR: Unknown module(s) in QT: contacts
I also tried this answer: How to install a missing Qt module?
But the module doesn't appear in the modules list:
What did I miss?
QtVersion:
I downloaded the qt-unified-linux-x64-3.0.2-online.run in this link: https://www.qt.io/download
I would try fetching from here, and install with configure/make/make install.
Looking at this documentation, it seems that there is a Contacts API, and a Contacts QML plugin.
Looking at the pro file in this example, there is no contact module appended to QT, but a CONFIG entry like this:
CONFIG += mobility
MOBILITY = contacts
I am trying to run the example that can be found here using gstreamer 1.6.4 on my ARM based board (https://cgit.freedesktop.org/gstreamer/gst-plugins-bad/tree/tests/examples/qt/qml)
I have Qt 5.5.1 installed and I have built gstreamer 1.6.4 and all the relevant plugins but when I run the example, it cannot find the GLVideoItem component and comes back with:
qrc:/main.qml:7 module "org.freedesktop.gstreamer.GLVideoItem" is not installed
Now, my question is how can I check if this component is installed on my system?
Also, do I need to rebuild qt linking against the new installation of gstreamer to be able to use this component?
[EDIT]
I also noticed creating qmlglsink element as get_element_factory_make("qmlglsink", NULL) returns NULL.
From shell:
gst-inspect-1.0 qmlglsink
I would check the ldd on your app of which GStreamer is used (if you have some system GStreamer and compiled one).. then you will have to set proper paths to pick the proper one.
ldd ./your-app | grep -i gst
Notice the PKGCONFIG in your .pro file (in the tutorial you linked) - you may check what is pkg config thinking about that:
pkg-config --cflags --libs gstreamer-1.0 gstreamer-video-1.0
I'm new to opencv. I installed it on my computer using cmake following the tutorial in their website.
mkdir Desctop/opencv
cd Desctop/opencv
git clone https://github.com/Itseez/opencv.git
cd opencv
mkdir release
cd release
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local ..
make
sudo make install
And to compile with opencv using cmake, I add the CMakeLists.txt file in the cpp file directory then execute
cd <cpp file directory>
cmake .
make
But now I know more about opencv. I know that I can make GUI windows with it; I can make buttons, scroll bars and many other UI controls.
But I can't use the GUI tools unless I integrated cmake with QT.I'm not sure how should it be, but I thing it would be something like
cmake -D WITH_QT=ON ..
Reference
But the problem is that I've already installed opencv and I don't know how can I change it's configurations to use QT.
I tried to install cmake-gui to change the opencv installation configurations but I didn't find anything for opencv in the program.
My questions
Do I need to re-install opencv or it's possible to change the settings or changing the content of CMakeLists.txt file?
How can I change the configurations of the current opencv installation so it support QT?
would I need to change the CMakeLists.txt file after changing opencv's configurations?
I've try few things but I still have this error when trying to cmake for blackfin:
CMake Error at CMakeLists.txt:116 (message):
Fatal error: QT (version >= 4.5.0) required. Cmake tries to detect QT4 by
searching for 'qmake' in your PATH.If you have QT4 installed, make sure
qmake is found in your PATH. If you compiled QT4 yourself make sure your
new qmake ist found _first_ in your PATH.
I'm trying to compile the source of musescore 0.9.5 to keep it compatible with the existing version of QT in uClinux options
What I did is to compile the uClinux kernel with QT lib so I can have the suitable embedded QT.
then I modified the Makefile of musescore to build with uclinux compilers. I've try different things so I show here the latest trial:
bfin:
mkdir build;
mkdir install; \
cd build;
cmake -DCMAKE_TOOLCHAIN_FILE=bfin.cmake -DCMAKE_VERBOSE_MAKEFILE=TRUE -\
DQT_QMAKE_EXECUTABLE=/home/william/Development_new/Music_Recognition/code/uCLin\
ux/rev2011R1/uclinux-dist/lib/qt-embedded/build-qt-embedded-linux-opensource-sr\
c-4.5.1/bin -libdir=/home/william/Development_new/Music_Recognition/cod\
e/uCLinux/rev2011R1/uclinux-dist/lib/qt-embedded/build-qt-embedded-linux-openso\
urce-src-4.5.1/lib \
-DCMAKE_INSTALL_PREFIX="${PREFIX}" \
mscore;
in the CMakeLists.txt I did add:
link_directories(/home/william/Development_new/Music_Recognition/code/uCLinux/r\
ev2011R1/uclinux-dist/lib/qt-embedded/build-qt-embedded-linux-opensource-src-4.\
5.1/bin)
SET(CMAKE_MODULE_PATH /home/william/Development_new/Music_Recognition/code/uCLi\
nux/rev2011R1/uclinux-dist/lib/qt-embedded/build-qt-embedded-linux-opensource-s\
rc-4.5.1/bin)
SET(CMAKE_PREFIX_PATH /home/william/Development_new/Music_Recognition/code/uCLi\
nux/rev2011R1/uclinux-dist/lib/qt-embedded/build-qt-embedded-linux-opensource-s\
rc-4.5.1/bin)
SET(QT_QMAKE_EXECUTABLE /home/william/Development_new/Music_Recognition/code/uC\
Linux/rev2011R1/uclinux-dist/lib/qt-embedded/build-qt-embedded-linux-opensource\
-src-4.5.1/bin)
my bfin.cmake look like that:
# this one is important
SET(CMAKE_SYSTEM_NAME Linux)
#this one not so much
SET(CMAKE_SYSTEM_VERSION 1)
#
SET (BFIN "/opt/uClinux/bfin-uclinux")
# specify the cross compiler
SET(CMAKE_C_COMPILER ${BFIN}/bin/bfin-uclinux-gcc)
SET(CMAKE_CXX_COMPILER ${BFIN}/bin/bfin-uclinux-g++)
SET(CMAKE_LINKER ${BFIN}/bin/bfin-uclinux-ld)
#/opt/uClinux/bfin-uclinux/bfin-uclinux/runtime/usr/lib
LINK_DIRECTORIES("${BFIN}/usr/lib")
SET(CMAKE_FIND_ROOT_PATH
/opt/uClinux/bfin-uclinux/bfin-uclinux
/opt/uClinux/bfin-linux-uclibc
/opt/uClinux/bfin-linux-uclibc/bfin-linux-uclibc/runtime)
# search for programs in the build host directories
SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
# for libraries and headers in the target directories
SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
Thanks in advance for the help,
William
You need to put qmake in your $PATH. If you prefer to use QT_QMAKE_EXECUTABLE it has to point to the actual qmake binary and not the directory.
That being said, MuseScore 0.9.5 is a very very old version of MuseScore, the current version is 1.1 and 1.2 is coming soon. Check http://musescore.org for more information about MuseScore and don't hesitate to contact the developers on #musescore on freenode.net or on the developer mailing list at http://musescore.org/mailing-list