How properly use Gstreamer in QtWidget? - qt

Question

I want to play a local file inside the QVideowidget by using the gstreamer. I tested gstreamer in the terminal without any problem with:
gst-launch-1.0 videotestsrc ! videoconvert ! autovideosink,and it showed this
But when I came to Qt,
#include <QApplication>
#include <QMediaPlayer>
#include <QWidget>
#include <QVideoWidget>
#include <gst/gst.h>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QVideoWidget *videoWidget = new QVideoWidget;
QMediaPlayer *player = new QMediaPlayer;
videoWidget->show();
player->setVideoOutput(videoWidget);
player->setMedia(QUrl("gst-launch-1.0 videotestsrc ! videoconvert ! autovideosink"));
// player->setMedia(QUrl("gst-launch-1.0 videotestsrc ! xvimagesink name=\"qtvideosink\""));
// player->setMedia(QUrl("gst-pipeline udpsrc port=5801 ! application/x-rtp,payload= (int)96,encoding-name=(string)H264,clock-rate=(int)90000 ! rtpjitterbuffer latency=50 ! rtph264depay ! h264parse ! omxh264dec ! videoconvert ! ximagesink"));
player->play();
return a.exec();
}
and in my .pro file I put these:
CONFIG += link_pkgconfig
PKGCONFIG += gstreamer-1.0
PKGCONFIG += gstreamer-video-1.0
I faced the following error:
DirectShowPlayerService::doSetUrlSource: Unresolved error code 0x80040216 (IDispatch error #22)
the output is:
I searched a lot, but I couldn't solve the issue. Could anyone please help me?

Answer 1

I could play a video test inside the Qwidget with the below method. Be aware that picking a compatible sink is essential. for more information about sink (and other elements), use gst-inspect-1.0 | findstr sink in the terminal.
#include <gst/gst.h>;
#include <gst/video/videooverlay.h>;
#include <QApplication>;
#include <QTimer>;
#include <QWidget>;
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
app.connect(&app, SIGNAL(lastWindowClosed()), &app, SLOT(quit ()));
if (!g_thread_supported ())
g_thread_init (NULL);
gst_init (&argc, &argv);
// prepare the pipeline
GstElement *pipeline = gst_pipeline_new ("xvoverlay");
GstElement *src = gst_element_factory_make ("videotestsrc", NULL);
GstElement *sink = gst_element_factory_make ("glimagesink", NULL);
gst_bin_add_many (GST_BIN (pipeline), src, sink, NULL);
gst_element_link (src, sink);
// getting more information
gst_debug_set_active(true);
gst_debug_set_default_threshold(GST_LEVEL_WARNING);
QWidget window;
window.resize(320, 240);
window.show();
WId xwinid = window.winId();
gst_video_overlay_set_window_handle (GST_VIDEO_OVERLAY (sink), xwinid);
// run the pipeline
GstStateChangeReturn sret = gst_element_set_state (pipeline,
GST_STATE_PLAYING);
if (sret == GST_STATE_CHANGE_FAILURE) {
gst_element_set_state (pipeline, GST_STATE_NULL);
gst_object_unref (pipeline);
// Exit application
QTimer::singleShot(0, QApplication::activeWindow(), SLOT(quit()));
}
int ret = app.exec();
window.hide();
gst_element_set_state (pipeline, GST_STATE_NULL);
gst_object_unref (pipeline);
return ret;
}
the output inside widget: