I'm trying to get phonon4qt5 to work with QT5 but I'm getting:
WARNING: bool Phonon::FactoryPrivate::createBackend() phonon backend plugin could not be loaded
WARNING: Phonon::createPath: Cannot connect Phonon::MediaObject ( no objectName ) to Phonon::AudioOutput ( no objectName ).
I've installed all the phonon related packages with apt.
I've added phonon4qt5 to my QT += in the .pro and LIBS += -L/home/fred/phonon-4.8.3/build5/phonon -lphonon4qt5 (tried several paths I found on my system)
And I've included these in my header:
#include <phonon4qt5/phonon/AudioDataOutput>
#include <phonon4qt5/phonon/AudioOutput>
#include <phonon4qt5/phonon/MediaObject>
#include <phonon4qt5/phonon/SeekSlider>
#include <phonon4qt5/phonon/VolumeSlider>
#include <phonon4qt5/phonon/AudioOutput>
Can someone point me to the correct direction?
(please don't suggest to use QMultimedia, since that's what I'm trying to get away from since there is no way to get the intensity of the sound output being played (in order to build a VU Meter..))
On the .cpp side I'm just doing:
Phonon::MediaObject *music =
Phonon::createPlayer(Phonon::MusicCategory,
Phonon::MediaSource("/home/fred/cpp/config/rol1.ogg"));
music->play();
Thank you for all your time and attention :-)
Best regards.
Fred.
Related
Question is simple; I get an error "Unknown module QWebEngineView" when I write the line Qt += QWebEngineView in .pro file.
How to get rid of this ?
I have tried many solutions but still got the error when compiling. If you got a solution please explain it entirely step by step.
I run Qt 5.10.1 with Ming32 5.30.
Try to use msys2 project that contains mingw64 with patches for qt5.
Write in your .pro file
QT += webenginewidgets
Add
#include <QWebEngineView>
in file that will use QWebEngineView class
I am re-engineering an aspect of current existing software in C++ that uses Qt 5.6. I am trying to create a bar chart that can represent the data stored in a table of int(s).
I used the Qt example in my code for a bar chart:
Includes:
#include <QChart>
#include <QBarSet>
#include <QBarSeries>
I attempted to put the includes in the .cpp file however for some reason the classes were not recognized unless they were forward declared so I moved the includes to the header file such that:
#include <QChart>
#include <QBarSet>
#include <QBarSeries>
class QChart;
class QBarSet;
class QBarSeries;
Code:
QBarSet *mainSet = new QBarSet("Data");
.
.
.
(I'll leave the rest of the code out since it really isn't important for the answer)
With the above code (new QBarSet("Data")) QBarSet is underlined in red in visual studio stating "incomplete type is not allowed".
I figure the issue is due to the fact I am trying to use Qt 5.6 for the graphs so I refereed to their website.
From Qt's Qt Charts 2.1.0 website:
In Qt 5.6 release the module binaries will still be available only
with the commercial packages.
That is where I am stuck.
Anyone know my issue or how I can get Qt bar charts for qt 5.6 (if possible)?
Found this resource:
https://doc.qt.io/qt-5/qtcharts-index.html
Stupid mistake, I was importing the wrong files. I removed all the includes that I had in my header file and put the following and it worked fine.
Header:
#include <QtCharts>
using namespace QtCharts;
Source:
QBarSet *mainSet = new QBarSet("Data");
.
.
.
For my UE4 project I want to use the GDCM libraries for C++ to load CT Scans. So I really tried a lot the last few days but I'm still not able to use GDCM... But where is the error? Can someone help me?
I created the dll and lib files with CMake (VS 2013 Win64) successfully.
I put all the libs in ...Unreal Projects\VolumeImport\ThirdParty\Includes\GDCM\Libraries
I added each of the 16 libs in the VolumeImport.Build.cs with
PublicAdditionalLibraries.Add(Path.Combine(LibrariesPath, "gdcmMSFF.lib"));
PublicAdditionalLibraries.Add(Path.Combine(LibrariesPath, "gdcmCommon.lib")); ...
I put all the header files in Unreal Projects\VolumeImport\ThirdParty\Includes\GDCM\Includes
I set the Includepath to this location in the project properties.
I put all the dlls in C:\Windows\System32
Then I used the headers:
#include "VolumeImport.h"
#include <gdcmVersion.h>
#include <gdcmReader.h>
#include <gdcmPixmapReader.h>
#include <gdcmImageReader.h>
#include <gdcmAttributes.h>
bool CTFileLoader::Convert_DICOM()
{
/** ... other well working code ... */
gdcm::Trace::SetDebug(false); gdcm::Trace::SetError(true);
gdcm::ImageReader reader;
reader.SetFilename(files_to_process[i].c_str());
if(!reader.Read()) { }
}
And I get an error in the gdcmMediaStorage.h: "error C4515: 'gdcm': Namespace uses itself."
I tried using different includes but this causes diffrent errors in diffrent headers... Is there something wrong with the libraries? But I'm sure they were added, because using only the gdcmTrace.h and the gdcm::Trace::functions works fine.
Now I got the solution:
In my VolumeImport.Build.cs I additionally added the DLLs:
PublicDelayLoadDLLs.Add(Path.Combine(LibrariesPath, "gdcmMSFF.dll")); ...
I changed the gdcmMediaStorage.h file: Comment out the "using namespace gdcm;"
Furthermore I had dynamic_cast problems with this big library and it needs to enable RTTI
I want to use gstreamer library for video programming and I read that Qt5.5.0 provided support for gstreamer-1.0, which is the library I use. I downloaded firstly version 1.0.7, but I got the following error, so I downloaded the latest version 1.5.2, which I am trying to use now.
I managed to link the gstreamer library header files, so I didn't build it, but just include its path and access the header files and libs. Anyway, now I have an error of The program has unexpectedly finished. When I try to debug it, I get the following error in a pop-up:
During startup program excited with code 0xc0000135.
On General Messages:
:1:24: Reading only version 1.1 parts.
:10:5: Expected only Component and ModuleApi object definitions.
I read many questions related to this error, but none helped, I think is an error with the gstreamer library, but may be a compiler/debugger error too, as I read in some threads.
I checked my PATH variable, as I also can not run the program outside Qt (by trying to run the .exe in debug folder of the build) - the error : library Qt5Cored.dll missing - and I found this paths:
C:\Qt\Qt5.5.0_Android\5.5\mingw492_32\lib;
C:\Users\user\Documents\build-GStreamer-test5-Desktop_Qt_5_5_0_MinGW_32bit-Debug;
C:\Qt\Qt5.5.0_Android\5.5\mingw492_32\bin;
C:\Qt\Qt5.5.0_Android\Tools\mingw492_32\bin;
C:\Windows\system32; C:\Windows; C:\Windows\System32\Wbem; C:\Windows\System32\WindowsPowerShell\v1.0;
C:\Program Files\Skype\Phone\ (I dont know why is this included, but it was there when I checked )
I am relatively new to Qt, and never encountered this error before. If you need any code:
.pro:
QT += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = GStreamer-test5
TEMPLATE = app
SOURCES += main.cpp
mainwindow.cpp
HEADERS += mainwindow.h
FORMS += mainwindow.ui
INCLUDEPATH += C:/gstreamer/1.0/x86/include/gstreamer-1.0
C:/gstreamer/1.0/x86/lib/gstreamer-1.0/include
C:/gstreamer/1.0/x86/include/glib-2.0
C:/gstreamer/1.0/x86/lib/glib-2.0/include
LIBS += -L C:/gstreamer/1.0/x86/lib/ -lgstreamer-1.0
and .main:
#include "mainwindow.h"
#include <QApplication>
#include <QDebug>
#include <stdio.h>
#include "gst/gst.h"
void *__gxx_personality_v0;
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
const gchar *nano_str;
guint major, minor, micro, nano;
gst_init (&argc, &argv);
gst_version (&major, &minor, µ, &nano);
if (nano == 1)
nano_str = "(CVS)";
else if (nano == 2)
nano_str = "(Prerelease)";
else
nano_str = "";
// printf ("This program is linked against GStreamer %d.%d.%d %s\n", major, minor, micro, nano_str);
qDebug() << "This program is linked against GStreamer %d.%d.%d %s\n", major, minor, micro, nano_str ;
return a.exec();
Firstly, I had the error :
undefined reference to `__gxx_personality_v0' , but fixed it by adding *void __gxx_personality_v0; , although I don't know what excatly it is.
Its been three days I struggle with this problem. Any help appreciated, or maybe if you can help me by some code on how to access the header files and libs, or how the configuration of the debugger options / PATH must be.
I am using Qt5.5.0 for Android, for Windows I use MinGW 4.9.2 32 bit compiler and GNU gdb 7.8 as debugger.
Thanks in advance!
I had similar problems in my project that was using both Qt and Gstreamer.
The сause of "undefined reference to `__gxx_personality_v0'" error is that Qt and GStreamer for windows from official sites were built using different compilers and their libstdc++ libraries are not compatible - they are using different exception handling methods.
In fact, GStreamer is pure C library. The only component of it that was written in C++ is taglib library. If you will build this lib from sources using your MinGW compiler, and then replace it in the GStreamer folder, the problem of incompatibility will be solved.
In more detail you can read here: https://github.com/knowthelist/knowthelist.
I managed to solve the above problem. I had to include in the .exe folder (the build-debug folder) all the dlls included, so I tried to run the .exe from there, not run it from Qt, and some errors with dlls missing gave me the names of the dlls. I found some in my library bin folder and some downloaded, and now everything seems fine :)
I have QT 5.1.1 installed on my machine, but I'm having some troubles using it. I'm trying to run the following simple program that requires QT:
//Playing Video
#include "cv.h"
#include "opencv2\objdetect\objdetect.hpp"
#include "opencv2\core\core.hpp"
#include "opencv2\highgui\highgui.hpp"
#include "opencv2\features2d\features2d.hpp"
#include "opencv2\calib3d\calib3d.hpp"
#include "opencv2\nonfree\nonfree.hpp"
#include "highgui.h"
#include <openbr\openbr_plugin.h>
using namespace cv;
static void printTemplate(const br::Template &t)
{
const QPoint firstEye = t.file.get<QPoint>("Affine_0");
const QPoint secondEye = t.file.get<QPoint>("Affine_1");
printf("%s eyes: (%d, %d) (%d, %d)\n", qPrintable(t.file.fileName()), firstEye.x(), firstEye.y(), secondEye.x(), secondEye.y());
}
int main(int argc, char *argv[])
{
br::Context::initialize(argc, argv);
// Retrieve classes for enrolling and comparing templates using the FaceRecognition algorithm
QSharedPointer<br::Transform> transform = br::Transform::fromAlgorithm("FaceRecognition");
QSharedPointer<br::Distance> distance = br::Distance::fromAlgorithm("FaceRecognition");
// Initialize templates
br::Template queryA("../data/MEDS/img/S354-01-t10_01.jpg");
br::Template queryB("../data/MEDS/img/S382-08-t10_01.jpg");
br::Template target("../data/MEDS/img/S354-02-t10_01.jpg");
// Enroll templates
queryA >> *transform;
queryB >> *transform;
target >> *transform;
printTemplate(queryA);
printTemplate(queryB);
printTemplate(target);
// Compare templates
float comparisonA = distance->compare(target, queryA);
float comparisonB = distance->compare(target, queryB);
// Scores range from 0 to 1 and represent match probability
printf("Genuine match score: %.3f\n", comparisonA);
printf("Impostor match score: %.3f\n", comparisonB);
br::Context::finalize();
return 0;
}
It also requires OpenCV 2.4.6.1 and OpenBR, but that's not the problem.
All the definitions (variables and functions) in the above code that are related to QT are undefined. I've tried to find the relevant h files in QT folder and to include them, but that did not succeed since I couldn't fine qtcore.h (but a different file named qtcore with lot's of includes that I don't now how to use). I've tried to add QT "include" directory under "additional include directories" in the project properties but that didn't work either. I've also tried to add QT "lib" folder under "additional library directories" but that also did not work.
Basically, I tried everything I could think of. Can someone please explain how to I use those QT definitions? I'm really stuck and I could use any help given.
Thanks,
Gil.
(Optional) Update to Qt 5.2.
Start Qt Creator.
Create a new Qt Widgets Application project. You can give the class/files random names, it doesn't matter. Uncheck the "generate form" option, as you don't need any forms.
Remove all the files other than main.cpp from the project. You do this by right-clicking on them in the project tree on the left and choosing Remove File.
Copy-paste your code into main cpp. Make sure you completely replace main.cpp's contents, the default contents shouldn't be there anymore.
Add the opencv library to the project. Right-click on the project's root, select "Add Library", and go from there.
Re-run qmake by right-clicking on the project root and selecting "Run qmake".
Build and run the project by pressing Ctrl-R (Cmd-R on mac).
Qt uses a (non-standard) custom toolchain that has to run before the Qt-dependent code can be compiled. I've never tried using Qt outside of QtCreator, but if you really need Qt I'd suggest you use the QtCreator IDE; if you're not using it already of course. It's a very decent IDE, even for non-Qt projects.
Also, if you haven't done so already, make sure the Qt SDK is installed; the headers alone are not enough. QtCreator by itself is also not enough, you'll need the SDK. If you don't feel like doing so, my suggestion would be to look at Poco. It's not a 1:1 replacement for Qt, but a very mature framework nevertheless.