unable to add Gstreamer element pading in sample code

I am using Gstreamer 1.0

I have run this following sample code on terminal:

gst-launch-1.0 -v videotestsrc ! videoconvert ! autovideosink

And the response of this is (This is the output on terminal):

Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...

/GstPipeline:pipeline0/GstVideoTestSrc:videotestsrc0.GstPad:src: caps = video/x-raw, width=(int)320, height=(int)240, framerate=(fraction)30/1, multiview-mode=(string)mono, format=(string)YV12, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive

/GstPipeline:pipeline0/GstVideoConvert:videoconvert0.GstPad:src: caps = video/x-raw, width=(int)320, height=(int)240, framerate=(fraction)30/1, multiview-mode=(string)mono, format=(string)YV12, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive

/GstPipeline:pipeline0/GstAutoVideoSink:autovideosink0.GstGhostPad:sink.GstProxyPad:proxypad0: caps = video/x-raw, width=(int)320, height=(int)240, framerate=(fraction)30/1, multiview-mode=(string)mono, format=(string)YV12, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive

/GstPipeline:pipeline0/GstAutoVideoSink:autovideosink0/GstXvImageSink:autovideosink0-actual-sink-xvimage.GstPad:sink: caps = video/x-raw, width=(int)320, height=(int)240, framerate=(fraction)30/1, multiview-mode=(string)mono, format=(string)YV12, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive

/GstPipeline:pipeline0/GstAutoVideoSink:autovideosink0.GstGhostPad:sink: caps = video/x-raw, width=(int)320, height=(int)240, framerate=(fraction)30/1, multiview-mode=(string)mono, format=(string)YV12, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive

/GstPipeline:pipeline0/GstVideoConvert:videoconvert0.GstPad:sink: caps = video/x-raw, width=(int)320, height=(int)240, framerate=(fraction)30/1, multiview-mode=(string)mono, format=(string)YV12, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive

Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock

I have created the elements and the Pas templates, I am not sure where in the code do I add (if that is the term here to use) or initialise them.

Objective. I want to exactly replicate the command (that is given above) in C++. My code up till now is given below:

#include <iostream>
#include <gst/gst.h>
#include <gst/rtp/gstrtpbuffer.h>

GstStaticPadTemplate my_srctemplate = GST_STATIC_PAD_TEMPLATE ("src", // the name of the pad
                                                        GST_PAD_SRC,    // the direction of the pad
                                                        GST_PAD_ALWAYS,  // when this pad will be present
                                                        GST_STATIC_CAPS (        // the capabilities of the padtemplate
                                                                "video/x-raw, "
                                                                "width=(int)320,"
                                                                "height=(int)240,"
                                                                "framerate=(fraction)30/1,"
                                                                "multiview-mode=(string)mono"
                                                                "format=(string)YV12,"
                                                                "pixel-aspect-ratio=(fraction)1/1,"
                                                                "framerate=(fraction)30/1,"
                                                                "interlace-mode=(string)progressive"
                                                                )
                                                        );
GstStaticPadTemplate my_sinktemplate = GST_STATIC_PAD_TEMPLATE ("sink", // the name of the pad
                                                        GST_PAD_SINK,    // the direction of the pad
                                                        GST_PAD_ALWAYS,  // when this pad will be present
                                                        GST_STATIC_CAPS (        // the capabilities of the padtemplate
                                                                "video/x-raw, "
                                                                "width=(int)320,"
                                                                "height=(int)240,"
                                                                "framerate=(fraction)30/1,"
                                                                "multiview-mode=(string)mono"
                                                                "format=(string)YV12,"
                                                                "pixel-aspect-ratio=(fraction)1/1,"
                                                                "framerate=(fraction)30/1,"
                                                                "interlace-mode=(string)progressive"
                                                                )
                                                        );
gchar *ElementName(GstElement *varname)
{
    gchar *givenname;

    g_object_get (G_OBJECT(varname), "name", &givenname, NULL);

    return(givenname);
}

int createLocalElement(GstElement *varname,GstElementFactory *factoryname,const gchar *givenname)
{
    gchar *elementname;

    varname = gst_element_factory_create(factoryname, givenname);
    if (!varname)
        return(-1);

    elementname = ElementName(varname);

    std::cout << "Element created : " << elementname <<  std::endl;
    //g_free (elementname);

    return(0);
}

The Main function:

int main(int argc, char *argv[])
 {
   GstElement *pipeline,*sink,*convertVdo,*source;
   GstElementFactory *source_factory, *sink_factory,*middlelayer_factory;
   GstStateChangeReturn ReturnStat;

   gst_init (&argc, &argv);

   /* Find factories for the elements */
   source_factory = gst_element_factory_find ("videotestsrc");
   sink_factory = gst_element_factory_find ("autovideosink");
   middlelayer_factory = gst_element_factory_find ("videoconvert");

   /* create element */
   if(0!=createLocalElement(sink, sink_factory, "VdoSink")){
      g_print ("Failed to create element of type 'autovideosink'\n");
      return(-1);
   }

   if(0!=createLocalElement(convertVdo, middlelayer_factory, "VdoCnvrt")){
      g_print ("Failed to create element of type 'videoconvert'\n");
      return(-1);
   }

   if(0!=createLocalElement(source, source_factory, "VdoSrc")){
      g_print ("Failed to create element of type 'videotestsrc'\n");
      return(-1);
    }

   /* Create the empty pipeline */
   pipeline = gst_pipeline_new ("test-pipeline");


   /* Build the pipeline */
   gst_bin_add_many (GST_BIN (pipeline), source, sink, NULL);


   /* Link the elemnts in pipeline */
   if(gst_element_link_many (source, convertVdo, sink, NULL) != TRUE) {
       g_printerr ("Elements could not be linked : %s to %s to %s\n",ElementName(source), ElementName(convertVdo), ElementName(sink));
       gst_object_unref (pipeline);
       return -1;
   }


   /* Start playing */
   ReturnStat = gst_element_set_state (pipeline, GST_STATE_PAUSED);

   if (ReturnStat == GST_STATE_CHANGE_FAILURE) {
      g_printerr ("Unable to set the pipeline to the playing state (check the bus for error messages).\n");
   }

   g_printerr ("Pipeline set to the Paused state \n");


  // gst_object_unref (GST_OBJECT (pipeline));

   std::cout << "Elements unreferenced" << std::endl;

   //std::cout << "This program is linked against GStreamer" << std::endl;
   return(0);
 }

Any help is appreciated :)
Regards,