an approach to Gstreamer with Vala

main.vala

using Gst;

public int main(string args[])
{
	Gst.init(ref args);
	
	Gst.Element screen = Gst.ElementFactory.make ("ximagesrc", "source");
	Gst.Element color_convert = Gst.ElementFactory.make ("videoconvert", "convert");
	Gst.Element encoder = Gst.ElementFactory.make ("x264enc","encoder");
	Gst.Element flv_muxer = Gst.ElementFactory.make ("flvmux", "muxer");
	Gst.Element file = Gst.ElementFactory.make ("filesink", "sink");

	if (screen == null || color_convert == null || encoder == null || flv_muxer == null || file == null) {
		stderr.puts ("Couldn't create a element:\n");

		if (screen == null) stderr.puts ("screen");
		if (color_convert == null) stderr.puts ("color converter\n");
		if (encoder == null) stderr.puts ("x264 encoder");
		if (flv_muxer== null) stderr.puts ("flv muxer");
		if (file == null) stderr.puts ("file sink");

		return -1;
	}

	// create a pipeline
	Pipeline pipe = new Pipeline ("test");

	pipe.add_many (
		screen,
		color_convert,
		encoder,
		flv_muxer,
		file);

	// get a bus before setting playing state
	Bus bus = pipe.get_bus ();

	Message msg = bus.timed_pop_filtered (Gst.CLOCK_TIME_NONE, Gst.MessageType.ERROR | Gst.MessageType.EOS);

	if (msg != null)
	{
		switch (msg.type)
		{
			case Gst.MessageType.ERROR:
				break;
			case Gst.MessageType.EOS:
				stdout.puts ("Stream ended");
				break;
			default:
				assert_not_reached();
		}
	}

	// various check
	
	bool pipe_link = screen.link_many (
			color_convert,
			encoder,
			flv_muxer,
			file);


	if ( !pipe_link )
	{
		stderr.puts ("Could'n link some elements\n");
		return -1;
	}


	// set parameters from ximagesrc
	// screen.set ("use-damage", true);
	screen.set ("num-buffers", 100);
	// screen.set ("framerate", 25/1);
	screen.set ("endx", 50);
	screen.set ("endy", 50);
	file.set ("location", "./test.flv");


	Gst.StateChangeReturn ret = pipe.set_state (Gst.State.PLAYING);

	if (ret == Gst.StateChangeReturn.FAILURE) {
		stderr.puts ("Couldn't start pipeline\n");
		return -1;
	}
	else if ( ret == Gst.StateChangeReturn.SUCCESS)
	{
		stdout.puts ("Pipeline is playing\n");
	}

	pipe.set_state (Gst.State.NULL);

	return 0;
}