Gstreamer with Qtwidgets

himanshu.d

Hi Team,

I am trying to achieve rendering of video on qtwidget using gstreamer pipeline. After searching I came across qt5videosink gstreamer plugin.

Below is the pipeline I am using.

gst-launch-1.0 videotestsrc ! qt5videosink

Pipeline is running but no out widget is opening.

Logs:

User-2:~$  gst-launch-1.0 -v videotestsrc ! qt5videosink
Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...
/GstPipeline:pipeline0/GstVideoTestSrc:videotestsrc0.GstPad:src: caps = video/x-raw, format=(string)BGRA, width=(int)320, height=(int)240, framerate=(fraction)30/1, multiview-mode=(string)mono, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive
/GstPipeline:pipeline0/GstQtVideoSink_qt5:qtvideosink_qt5-0.GstPad:sink: caps = video/x-raw, format=(string)BGRA, width=(int)320, height=(int)240, framerate=(fraction)30/1, multiview-mode=(string)mono, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive
Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
Redistribute latency...
New clock: GstSystemClock
^Chandling interrupt.
Interrupt: Stopping pipeline ...
Execution ended after 0:00:05.508780834
Setting pipeline to NULL ...
Freeing pipeline ...

Could you please help me here. How to actually use qt5videosink plugin in gstreamer pipeline?

Thanks,

SGaist

Hi and welcome to devnet,

AFAIK, this plugin is to be used within a Qt application through a custom pipeline. It won't create a widget out of nothing on the command line.

himanshu.d

@SGaist ,

Qt Version

QMake version 3.1
Using Qt version 5.15.3 in /usr/lib/x86_64-linux-gnu

Below is the example I have used using Qt Application. Still it opens up two windows.

I am running this application on my ubuntu machine.

I have took reference from QVideoWidget.

Below is the code:

#include <QApplication>
#include <QMainWindow>
#include <QVideoWidget>
#include <QMediaPlayer>
#include <QMediaPlaylist>

int main(int argc, char * argv[])
{
    QApplication testApp(argc, argv);
    QMainWindow w;

    QVideoWidget videoWidget(&w);
    w.setCentralWidget(&videoWidget);

    QMediaPlayer *player = new QMediaPlayer(&w);

    player->setMedia(QUrl("gst-pipeline: videotestsrc ! xvimagesink name=\"qtvideosink\""));
    player->setVideoOutput(&videoWidget);
    
    w.show();

    player->play();

    return testApp.exec();
}

O/P Screen Shot

As you can see in the below screenshot it is opening two windows.

Below is the error in console while I run the application

** (application:168481): CRITICAL **: 14:30:01.955: gst_vaapi_window_x11_new_with_xid: assertion 'xid != None' failed

Appreciate your help here!

Thanks

SGaist

What happens if you use qtvideosink directly ?

Numerator

void GstPlayer::setVideoOutput(QWidget *widget)
{
    _hwndVideo = widget->winId();
}

    gst_video_overlay_set_window_handle(GST_VIDEO_OVERLAY(customData.pipeline), _player->hwndVideo());