Appsrc webrtcsink example

I am new to gstreamer and I am trying to evaluate it for a project that
streams video to web browsers.

I can run the video test src example using gst-launch and that works just
fine. What I am having some trouble with is modifying the example to send
raw video frames via appsrc. The modified example runs with playbin and I
can see my test video. When the sink is webrtcsink, it runs without
complaining, but the signaling server is never contacted based on the logs
I see. Is there some configuration I am missing?

Source

#include <gst/gst.h>

static GMainLoop *loop;
#define WIDTH 640
#define HEIGHT 480

static void
cb_need_data (GstElement *appsrc,
          guint       unused_size,
          gpointer    user_data)
{
  static gboolean white = FALSE;
  GstBuffer *buffer;
  GstFlowReturn ret;
  GstMapInfo map;
  static int sample = 0;
  g_print("sample\n");
  buffer = gst_buffer_new_and_alloc (WIDTH * HEIGHT * 3);
  gst_buffer_map (buffer, &map, GST_MAP_WRITE);

  guchar *raw = (guchar *) map.data;
  int i = 0;
  guchar value = sample % 255;
  for( i = 0; i < WIDTH * HEIGHT * 3; i++) {
    raw[i] = value;
  }

  g_signal_emit_by_name (appsrc, "push-buffer", buffer, &ret);

  if (ret != GST_FLOW_OK) {
    /* something wrong, stop pushing */
    g_main_loop_quit (loop);
  }

  gst_buffer_unmap (buffer, &map);
  sample++;
}

gint
main (gint argc, gchar *argv[])
{
  GstElement *pipeline, *appsrc, *conv, *videosink;

  /* init GStreamer */
  gst_init (&argc, &argv);
  loop = g_main_loop_new (NULL, FALSE);

  /* setup pipeline */
  pipeline = gst_pipeline_new ("pipeline");
  appsrc = gst_element_factory_make ("appsrc", "source");
  conv = gst_element_factory_make ("videoconvert", "conv");
  videosink = gst_element_factory_make ("webrtcsink", "videosink");
  GstStructure *meta = gst_structure_from_string("meta,name=gst-stream",
NULL);
  g_object_set(videosink, "meta", meta, NULL);

  /* setup */
  g_object_set (G_OBJECT (appsrc), "caps",
        gst_caps_new_simple ("video/x-raw",
                     "format", G_TYPE_STRING, "RGB",
                     "width", G_TYPE_INT, WIDTH,
                     "height", G_TYPE_INT, HEIGHT,
                     "framerate", GST_TYPE_FRACTION, 1, 1,
                     NULL), NULL);

  gst_bin_add_many (GST_BIN (pipeline), appsrc, conv, videosink, NULL);
  gst_element_link_many (appsrc, conv, videosink, NULL);
  /* setup appsrc */
  g_object_set (G_OBJECT (appsrc),
        "stream-type", 0,
        "is-live", TRUE,
        "format", GST_FORMAT_TIME, NULL);
  g_signal_connect (appsrc, "need-data", G_CALLBACK (cb_need_data), NULL);

  /* play */
  gst_element_set_state (pipeline, GST_STATE_PLAYING);
  g_main_loop_run (loop);

  /* clean up */
  gst_element_set_state (pipeline, GST_STATE_NULL);
  gst_object_unref (GST_OBJECT (pipeline));
  g_main_loop_unref (loop);

  return 0;
}