I am trying to use gstreamer to play video from a network camera in QWidget.
I am utilizing "mjpeg" stream of the camera.

I am able to successfully play the video in terminal using :
Qt Code: 
  1. gst-launch souphttpsrc location=http://169.254.75.39/video2.mjpg timeout=5 ! jpegdec ! xvimagesink
To copy to clipboard, switch view to plain text mode 

The same code I am trying to play in QWidget using this code:
Qt Code: 
  1. #include <glib.h>
  2. #include <gst/gst.h>
  3. #include <gst/interfaces/xoverlay.h>
  4.  
  5. #include <QApplication>
  6. #include <QTimer>
  7. #include <QWidget>
  8.  
  9. int main(int argc, char *argv[])
  10. {
  11.   if (!g_thread_supported ())
  12.     g_thread_init (NULL);
  13.  
  14.   gst_init (&argc, &argv);
  15.   QApplication app(argc, argv);
  16.   app.connect(&app, SIGNAL(lastWindowClosed()), &app, SLOT(quit ()));
  17.  
  18.   // prepare the pipeline
  19.  
  20.   GstElement *pipeline = gst_pipeline_new ("xvoverlay");
  21.   GstElement *src = gst_element_factory_make ("souphttpsrc",NULL);
  22.   GstElement *sink = gst_element_factory_make ("xvimagesink", NULL);
  23.   gst_bin_add_many (GST_BIN (pipeline), src, sink, NULL);
  24.   gst_element_link (src, sink);
  25.   g_object_set (src, "location", "http://169.254.75.39/video2.mjpg", NULL);
  26.   // prepare the ui
  27.  
  28.   QWidget window;
  29.   window.move(0,0);
  30.   window.resize(320, 240);
  31.   window.show();
  32.  
  33.   WId xwinid = window.winId();
  34.   gst_x_overlay_set_window_handle (GST_X_OVERLAY (sink), xwinid);
  35.  
  36.   // run the pipeline
  37.  
  38.   GstStateChangeReturn sret = gst_element_set_state (pipeline,
  39.       GST_STATE_PLAYING);
  40.   if (sret == GST_STATE_CHANGE_FAILURE) {
  41.     gst_element_set_state (pipeline, GST_STATE_NULL);
  42.     gst_object_unref (pipeline);
  43.     // Exit application
  44.     QTimer::singleShot(0, QApplication::activeWindow(), SLOT(quit()));
  45.   }
  46.  
  47.   int ret = app.exec();
  48.  
  49.   window.hide();
  50.   gst_element_set_state (pipeline, GST_STATE_NULL);
  51.   gst_object_unref (pipeline);
  52.  
  53.   return ret;
  54. }
To copy to clipboard, switch view to plain text mode 

When I run the code,all I am getting is a blank QWidget with nothing.

My gstreamer has been correctly setup in QT and I was able to play a sample pattern easily in QWidget.

I guess I am missing the decoder configuration in QT for 'jpegdec'
Can anyone tell how to correctly set it up?
Here is the .pro file content:
Qt Code: 
  1. QT       += core gui
  2.  
  3. TARGET = streaming
  4. TEMPLATE = app
  5.  
  6.  
  7. SOURCES += main.cpp\
  8.         mainwindow.cpp
  9.  
  10. HEADERS  += mainwindow.h
  11.  
  12. FORMS    += mainwindow.ui
  13.  
  14. CONFIG += link_pkgconfig
  15. PKGCONFIG += gstreamer-0.10\
  16. gstreamer-interfaces-0.10\
  17. gtk+-2.0\
  18.  
  19. QMAKE_CXXFLAGS += -fpermissive
To copy to clipboard, switch view to plain text mode 

P.S. : using ubuntu 12.04