MessageType

Description:

// See http://docs.gstreamer.com/x/ZgAF
// for a detailed description

public static int main (string[] args) {

	// Initialize GStreamer:
	Gst.init (ref args);

	// Create the elements:
	Gst.Element source = Gst.ElementFactory.make ("videotestsrc", "source");
	Gst.Element sink = Gst.ElementFactory.make ("autovideosink", "sink");

	// Create the empty pipeline:
	Gst.Pipeline pipeline = new Gst.Pipeline ("test-pipeline");

	if (source == null || sink == null || pipeline == null) {
		stderr.puts ("Not all elements could be created.\n");
		return -1;
	}

	// Build the pipeline:
	pipeline.add_many (source, sink);

	if (source.link (sink) != true) {
		stderr.puts ("Elements could not be linked.\n");
		return -1;
	}

	// Modify the source's properties:
	source.set ("pattern", 0);

	// Start playing:
	Gst.StateChangeReturn ret = pipeline.set_state (Gst.State.PLAYING);
	if (ret == Gst.StateChangeReturn.FAILURE) {
		stderr.puts ("Unable to set the pipeline to the playing state.\n");
		return -1;
	}

	// Wait until error or EOS:
	Gst.Bus bus = pipeline.get_bus ();
	Gst.Message msg = bus.timed_pop_filtered (Gst.CLOCK_TIME_NONE, Gst.MessageType.ERROR | Gst.MessageType.EOS);


	// Parse message:
	if (msg != null) {
		switch (msg.type) {
		case Gst.MessageType.ERROR:
			GLib.Error err;
			string debug_info;

			msg.parse_error (out err, out debug_info);
			stderr.printf ("Error received from element %s: %s\n", msg.src.name, err.message);
			stderr.printf ("Debugging information: %s\n", (debug_info != null)? debug_info : "none");
			break;

		case Gst.MessageType.EOS:
			print ("End-Of-Stream reached.\n");
			break;

		default:
			// We should not reach here because we only asked for ERRORs and EOS:
			assert_not_reached ();
		}
	}


	// Free resources:
	pipeline.set_state (Gst.State.NULL);

	return 0;
}

valac --pkg gstreamer-1.0 concepts.vala

Content:

Enum values:

• ANY - mask for all of the above messages.
• APPLICATION - message posted by the application, possibly via an application-specific element.
• ASYNC_DONE - Posted by elements when they complete an ASYNC StateChange.
• ASYNC_START - Posted by elements when they start an ASYNC StateChange.
• BUFFERING - the pipeline is buffering.
• CLOCK_LOST - The current clock as selected by the pipeline became unusable.
• CLOCK_PROVIDE - an element notifies its capability of providing a clock.
• DEVICE_ADDED - Message indicating a Device was added to a DeviceProvider (Since: 1.4)
• DEVICE_CHANGED - Message indicating a Device was changed a DeviceProvider (Since: 1.16)
• DEVICE_REMOVED - Message indicating a Device was removed from a DeviceProvider (Since: 1.4)
• DURATION_CHANGED - The duration of a pipeline changed.
• ELEMENT - element-specific message, see the specific element's documentation
• EOS - end-of-stream reached in a pipeline.
• ERROR - an error occurred.
• EXTENDED - Message is an extended message type (see below).
• HAVE_CONTEXT - Message indicating that an element created a context (Since: 1.2)
• INFO - an info message occurred
• INSTANT_RATE_REQUEST - Message sent by elements to request the running time from the pipeline when an instant rate change should be applied (which may be in the past when the answer arrives).
• LATENCY - Posted by elements when their latency changes.
• NEED_CONTEXT - Message indicating that an element wants a specific context (Since: 1.2)
• NEW_CLOCK - a new clock was selected in the pipeline.
• PROGRESS - A progress message.
• PROPERTY_NOTIFY - Message indicating a Object property has changed (Since: 1.10)
• QOS - A buffer was dropped or an element changed its processing strategy for Quality of Service reasons.
• REDIRECT - Message indicating to request the application to try to play the given URL(s).
• REQUEST_STATE - Posted by elements when they want the pipeline to change state.
• RESET_TIME - Message to request resetting the pipeline's running time from the pipeline.
• SEGMENT_DONE - pipeline completed playback of a segment.
• SEGMENT_START - pipeline started playback of a segment.
• STATE_CHANGED - a state change happened
• STATE_DIRTY - an element changed state in a streaming thread.
• STEP_DONE - a stepping operation finished.
• STEP_START - A stepping operation was started.
• STREAMS_SELECTED - Message indicating the active selection of Streams has changed (Since: 1.10)
• STREAM_COLLECTION - Message indicating a new StreamCollection is available (Since: 1.10)
• STREAM_START - Message indicating start of a new stream.
• STREAM_STATUS - status about a stream, emitted when it starts, stops, errors, etc.
• STRUCTURE_CHANGE - the structure of the pipeline changed.
• TAG - a tag was found.
• TOC - A new table of contents (TOC) was found or previously found TOC was updated.
• UNKNOWN - an undefined message
• WARNING - a warning occurred.

Methods:

• public unowned string get_name ()
  Get a printable name for the given message type.
• public Quark to_quark ()
  Get the unique quark for the given message type.