#include <gst/gst.h>

int main (int argc, char *argv[])
{
    GstElement *pipeline, *source, *sink;
    GstBus *bus;
    GstMessage *msg;
    GstStateChangeReturn ret;

    /* Initialize */
    gst_init(&argc,&argv);

    /* Create the elements */
    source = gst_element_factory_make("videotestsrc","source");
    sink = gst_element_factory_make("autovideosink","sink");

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

    if(!pipeline || !source || !sink)
    {
        g_printerr("Not all elements could be created!\n");
        return -1;
    }

    /* Build the pipeline */
    gst_bin_add_many(GST_BIN(pipeline),source,sink,NULL);
    if (gst_element_link(source,sink) != TRUE)
    {
        g_printerr("Elements could not be linked.!\n");
        gst_object_unref(pipeline);
        return -1;
    }

    /* Modify the source's properties */
    g_object_set(source, "pattern", 0 , NULL);

    /* Start playing */
    ret = gst_element_set_state(pipeline, GST_STATE_PLAYING);
    if (ret == GST_STATE_CHANGE_FAILURE)
    {
        g_printerr("Unable to set the pipeline to the playing state. \n");
        gst_object_unref(pipeline);
        return -1;
    }

    /* Wait until error or EOS */
    bus  = gst_element_get_bus (pipeline);
    msg = gst_bus_timed_pop_filtered(bus, GST_CLOCK_TIME_NONE, GST_MESSAGE_ERROR | GST_MESSAGE_EOS);

    if (msg != NULL)
    {
        GError *err;
        gchar *debug_info;

        switch (GST_MESSAGE_TYPE(msg))
        {
        case GST_MESSAGE_ERROR:
            gst_message_parse_error(msg, &err, &debug_info);
            g_printerr("Error received from element %s:%s\n",GST_OBJECT_NAME(msg->src),err->message);
            g_printerr("Debugging information: %s\n",debug_info ? debug_info : "none");
            g_clear_error(&err);
            g_free(debug_info);
            break;
        case GST_MESSAGE_EOS:
            g_print("End-of_Stream reached.\n");
            break;
        default:
            g_printerr("Unexpected message recevied.\n");
            break;
        }
        gst_message_unref(msg);
    }

    /* Free resources */
    gst_object_unref(bus);
    gst_element_set_state(pipeline, GST_STATE_NULL);
    gst_object_unref(pipeline);
    return 0;
}