can't see a video play but only music in Qt

Hi,

I want to play a video in my application. But whenever I try to runt he application, I get the message "WARNING: Phonon::createPath: Cannot connect Phonon::MediaObject ( no objectName ) to Phonon::VideoWidget ( no objectName )." And I can hear the music but not video. Here is my code

Code:

---

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    Phonon::VideoPlayer *player =
             new Phonon::VideoPlayer(Phonon::VideoCategory, this);
         player->play(QUrl("path"));
         player->show();
}
 
#include <QMainWindow>
#include <phonon/VideoPlayer>
#include <phonon/backendcapabilities.h>
#include <QUrl>
#include <phonon>
namespace Ui {
    class MainWindow;
}
 
class MainWindow : public QMainWindow
{
    Q_OBJECT
 
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
 
private:
    Ui::MainWindow *ui;
};

---

I tried to run the code from http://www.qtcentre.org/threads/3048...w-black-screen but didn't work. Can any one please tell me what else should be required to play a video.

Thank You,
Baluk

You have the correct decoder installed?

I am sorry but what decoder I should use. I thought Qt takes the default one that is provided in my windows vista, isn't it so. I don't have much idea about decoder stuff I am trying to find it anyway.

Thank You,
Baluk

Unless you have a codec capable of playing the video, all you'll get is audio.

We can't tell you which decoder to use as we don't know your file format.

I want to play avi, mp3 and mkv format file.

avi and mkv are only containers, what is the file type that you will be playing inside those containers? eg. xvid.

oke. File type is VLC media file.

No, it's not.

That's just the registered player you are using to play the file.

Oke. Now I got to understand what is file format. I want to play avc1 and MPGV codec files.

Install FFDShow

I have it installed on my system. My audio was playing with this codec support only.

http://bugreports.qt.nokia.com/browse/QTBUG-13062

Quote:

---

Originally Posted by hicham

http://bugreports.qt.nokia.com/browse/QTBUG-13062

---

So according to the link, I can't play a video using Qt 4.7. Is there any other way I could make it possible.

I moved to Qt 4.6.2 and tried to run my application. But I still couldn't succeed. Here I am copying my code. Could any one please check If it is running on your system.

Code:

---

#include <QMainWindow>
#include <phonon/VideoPlayer>
#include <phonon/VideoWidget>
#include <phonon/backendcapabilities.h>
#include <QUrl>
#include <phonon>
namespace Ui {
    class MainWindow;
}
 
class MainWindow : public QMainWindow {
    Q_OBJECT
public:
    MainWindow(QWidget *parent = 0);
    ~MainWindow();
 
protected:
    void changeEvent(QEvent *e);
 
private:
    Ui::MainWindow *ui;
};
 
#endif // MAINWINDOW_H
 
//.CPP file
 
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
 
        qDebug() << Phonon::BackendCapabilities::availableAudioOutputDevices();
 
        Phonon::MediaObject *mediaObject = new Phonon::MediaObject(this);
 
             Phonon::VideoWidget *videoWidget = new Phonon::VideoWidget(this);
             Phonon::createPath(mediaObject, videoWidget);
 
             Phonon::AudioOutput *audioOutput =
                 new Phonon::AudioOutput(Phonon::VideoCategory, this);
             Phonon::createPath(mediaObject, audioOutput);
             mediaObject->setCurrentSource(QUrl("file.mkv or .avi"));
            connect(mediaObject, SIGNAL(finished()), mediaObject, SLOT(deleteLater()));
             mediaObject->play();
 
}
 
MainWindow::~MainWindow()
{
    delete ui;
}
 
void MainWindow::changeEvent(QEvent *e)
{
    QMainWindow::changeEvent(e);
    switch (e->type()) {
    case QEvent::LanguageChange:
        ui->retranslateUi(this);
        break;
    default:
        break;
    }
}
 
//.pro file
 
#-------------------------------------------------
#
# Project created by QtCreator 2010-10-10T23:15:17
#
#-------------------------------------------------
 
QT       += opengl phonon multimedia
 
TARGET = video
TEMPLATE = app
 
 
SOURCES += main.cpp\
        mainwindow.cpp
 
HEADERS  += mainwindow.h
 
FORMS    += mainwindow.ui
 
wince*{
DEPLOYMENT_PLUGIN += phonon_ds9 phonon_waveout
}

---

Thank You,
baluk

Hi,

My problem is solved. Now I can play a video in my Qt app. It was solved when I enable the corresponding decoder in the ffdshow video decoder ( which is responsible for all format video play). Before I was overlooked the issue when running the application.

Quote:

---

Originally Posted by baluk

Hi,

My problem is solved. Now I can play a video in my Qt app. It was solved when I enable the corresponding decoder in the ffdshow video decoder ( which is responsible for all format video play). Before I was overlooked the issue when running the application.

---

Hi,
I am new to Qt and facing the same issue. I am using windows XP and also install k-Lite codec, but still not working, then I uninstalled that and installed FFDSHOW, do I need to configure anywhere in my system. Please suggest me.

Did you open the ffdshow window and check the available video types and if they are enabled or disabled.

I tried to play DIVX encoded .avi file. But it is not playing. I have also installed ffdshow and I have checked that DIVX XIDV codecs are enabled. Can somebody help me.

Quote:

---

Originally Posted by baluk

Hi,

My problem is solved. Now I can play a video in my Qt app. It was solved when I enable the corresponding decoder in the ffdshow video decoder ( which is responsible for all format video play). Before I was overlooked the issue when running the application.

---

Can you write, where and what did you do to see video?

can anybody tell me in ffdshow video decoder what option shud i enable for playing .avi video file.I can only hear the music but no video........