Update

subprojects/gst-docs/examples/bus_example.c

@@ -0,0 +1,79 @@
+#include <gst/gst.h>
+
+static GMainLoop *loop;
+
+static gboolean
+my_bus_callback (GstBus * bus, GstMessage * message, gpointer data)
+{
+  g_print ("Got %s message\n", GST_MESSAGE_TYPE_NAME (message));
+
+  switch (GST_MESSAGE_TYPE (message)) {
+    case GST_MESSAGE_ERROR:{
+      GError *err;
+      gchar *debug;
+
+      gst_message_parse_error (message, &err, &debug);
+      g_print ("Error: %s\n", err->message);
+      g_error_free (err);
+      g_free (debug);
+
+      g_main_loop_quit (loop);
+      break;
+    }
+    case GST_MESSAGE_EOS:
+      /* end-of-stream */
+      g_main_loop_quit (loop);
+      break;
+    default:
+      /* unhandled message */
+      break;
+  }
+
+  /* we want to be notified again the next time there is a message
+   * on the bus, so returning TRUE (FALSE means we want to stop watching
+   * for messages on the bus and our callback should not be called again)
+   */
+  return TRUE;
+}
+
+gint
+main (gint argc, gchar * argv[])
+{
+  GstElement *pipeline;
+  GstBus *bus;
+  guint bus_watch_id;
+
+  /* init */
+  gst_init (&argc, &argv);
+
+  /* create pipeline, add handler */
+  pipeline = gst_pipeline_new ("my_pipeline");
+
+  /* adds a watch for new message on our pipeline's message bus to
+   * the default GLib main context, which is the main context that our
+   * GLib main loop is attached to below
+   */
+  bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
+  bus_watch_id = gst_bus_add_watch (bus, my_bus_callback, NULL);
+  gst_object_unref (bus);
+
+  /* [...] */
+
+  /* create a mainloop that runs/iterates the default GLib main context
+   * (context NULL), in other words: makes the context check if anything
+   * it watches for has happened. When a message has been posted on the
+   * bus, the default main context will automatically call our
+   * my_bus_callback() function to notify us of that message.
+   * The main loop will be run until someone calls g_main_loop_quit()
+   */
+  loop = g_main_loop_new (NULL, FALSE);
+  g_main_loop_run (loop);
+
+  /* clean up */
+  gst_element_set_state (pipeline, GST_STATE_NULL);
+  gst_object_unref (pipeline);
+  g_source_remove (bus_watch_id);
+  g_main_loop_unref (loop);
+
+  return 0;
+}