Usage of the qtglvideosink

[Mandeep Sandhu]

Hi Robert,

I think you should read-up a little about Qt graphics-view a little before
attempting to use the QtGstreamer OpenGL widget. As I mentioned in previous
mail you will need to create a graphics scene, add a view to to it and then
add the video widget to the scene to make it work.

I thought it worked for you after you made those changes (according to your
last mail thread - "QtGStreamer: How to get run a
QGst::Ui::GraphicsVideoWidget")?

Here's your example with the required modifications done:

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QGst::init(&argc, &argv);

    QGraphicsScene* scene =  new QGraphicsScene;
    QGraphicsView* view = new QGraphicsView(scene);
    view->setViewport(new QGLWidget);

    QGst::Ui::GraphicsVideoSurface* surface = new
                                    QGst::Ui::GraphicsVideoSurface(view);
    QGst::Ui::GraphicsVideoWidget* widget = new
                                    QGst::Ui::GraphicsVideoWidget();

    widget->setSurface(surface);
    scene->addItem(widget);

    QGst::ElementPtr source = QGst::ElementFactory::make("videotestsrc");
    QGst::ElementPtr sink = surface->videoSink();
    QGst::PipelinePtr pipeline = QGst::Pipeline::create();
    pipeline->add(source);
    pipeline->add(sink);
    if(source->link(sink) == false)
        qDebug("Link failed");

    view->show();
    pipeline->setState(QGst::StatePlaying);

    return app.exec();
}

HTH,
-mandeep




On Sun, Mar 24, 2013 at 7:53 PM, pfarmer <flacone at gmx.de> wrote:

> Sorry for bothering you again about an Qt related topic. But I am not able
> to
> get the qtglvideosink running.
> I tried the two ways mentioned in
>
> http://gstreamer.freedesktop.org/data/doc/gstreamer/head/qt-gstreamer/html/qtvideosink_overview.html
> <
> http://gstreamer.freedesktop.org/data/doc/gstreamer/head/qt-gstreamer/html/qtvideosink_overview.html
> >  :
>  1) Usage without QtGStreamer
>  2) Usage with QtGStreamer
>
>
> *For 1 i tried this:*
>
> #include <QGst/Init>
> #include <QGst/Pipeline>
> #include <QGst/ElementFactory>
> #include <QGst/Ui/VideoWidget>
> #include <QGlib/Connect>
>
> #include <QApplication>
> #include <QGLWidget>
> #include <QDebug>
>
> int main(int argc, char *argv[])
> {
>         QApplication app(argc, argv);
>         QGst::init(&argc, &argv);
>
>         QGst::ElementPtr source =
> QGst::ElementFactory::make("videotestsrc");
>         QGst::ElementPtr sink =
> QGst::ElementFactory::make("qtglvideosink");
>
>         QGLWidget* glWidget = new QGLWidget();
>
>         glWidget->makeCurrent();
>         sink->setProperty("glcontext",
> (void*)QGLContext::currentContext());
>         glWidget->doneCurrent();
>
>         if(sink->setState(QGst::StateReady) != QGst::StateChangeSuccess)
>         {
>                 qWarning("Gl not available. Closing app.");
>                 app.exit();
>         }
>
>         QGst::PipelinePtr pipeline = QGst::Pipeline::create();
>         pipeline->add(source);
>         pipeline->add(sink);
>         if(source->link(sink) == false)
>                 qDebug("Link failed");
>
> //      QGlib::connect(sink, "update", glWidget, &QGLWidget::update());
>
>         glWidget->show();
>         pipeline->setState(QGst::StatePlaying);
>
>         return app.exec();
> }
>
> I am not able to connect the update signal to the slot QGLWidget::update().
> How can i do this? Or: do I have to do it? It also seems not enough to
> solely set the QLContext to the qtglvideosink; what esle I have to do?
>
>
>
> *And for 2 I tried this:*
>
> int main(int argc, char *argv[])
> {
>         QApplication app(argc, argv);
>         QGst::init(&argc, &argv);
>
>         QGst::ElementPtr source =
> QGst::ElementFactory::make("videotestsrc");
>         QGst::ElementPtr sink =
> QGst::ElementFactory::make("qtglvideosink");
>
>         QGst::Ui::VideoWidget* widget = new QGst::Ui::VideoWidget();
> //      QGLWidget* glWidget = new QGLWidget(widget);
>
> //      glWidget->makeCurrent();
> //      sink->setProperty("glcontext",
> (void*)QGLContext::currentContext());
> //      glWidget->doneCurrent();
> //      if(sink->setState(QGst::StateReady) != QGst::StateChangeSuccess)
> //      {
> //              qWarning("Closing app. Probably Gl not available.");
> //              app.exit();
> //      }
>
>         QGst::PipelinePtr pipeline = QGst::Pipeline::create();
>         pipeline->add(source);
>         pipeline->add(sink);
>         if(source->link(sink) == false)
>                 qDebug("Link failed");
>
>         widget->setVideoSink(sink);
>
>         pipeline->setState(QGst::StatePlaying);
>         widget->show();
>
>         return app.exec();
> }
>
> Here I don't know how to make the QGst::Ui::VideoWidget() openGL aware. I
> also can't inherit both the QGLWidget and the QGst::Ui::VideoWidget in one
> class since this is forbidden by Qt. How can I GL acceleration with a
> QGst::Ui::VideoWidget()?
>
> In the two cases above nothing happens, except that an empty widget pop's
> up.
>
> Thanks for any help,
> Robert.
>
>
>
> --
> View this message in context:
> http://gstreamer-devel.966125.n4.nabble.com/Usage-of-the-qtglvideosink-tp4659243.html
> Sent from the GStreamer-devel mailing list archive at Nabble.com.
> _______________________________________________
> gstreamer-devel mailing list
> gstreamer-devel at lists.freedesktop.org
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>
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