[gst-devel] gstreamer appliaction

[Sedji Gaouaou]

Hi all,

I am a newbe with gstreamer, and I am currently writting a application 
which will play a .avi file.
But I have a problem when trying to play both audio and video.

Here is my application:
In the main, if I comment the audio(gst_bin_add_many and 
gst_element_link_many) then the video works fine. Same thing appends if 
I comment the video part then the audio play just fine, but when trying 
both the video doesn't even start??

Am I missing something?

Regards,
Sedji


#include <gst/gst.h>
#include <glib.h>
#include <string.h>


static GstElement *source, *demuxer, *vdqueue, *adqueue, *vdsink, 
*adsink, *decvd, *decad;

void on_pad_added (GstElement *element, GstPad *pad)
{
	g_debug ("Signal: pad-added");
	GstCaps *caps;
	GstStructure *str;

	caps = gst_pad_get_caps (pad);
	g_assert (caps != NULL);
	str = gst_caps_get_structure (caps, 0);
	g_assert (str != NULL);

	if (g_strrstr (gst_structure_get_name (str), "video")) {
		g_debug ("Linking video pad to dec_vd");
		// Link it actually
		GstPad *targetsink = gst_element_get_pad (decvd, "sink");
		g_assert (targetsink != NULL);
		gst_pad_link (pad, targetsink);
		gst_object_unref (targetsink);
	}

	if (g_strrstr (gst_structure_get_name (str), "audio")) {
		g_debug ("Linking audio pad to dec_ad");
		// Link it actually
		GstPad *targetsink = gst_element_get_pad (decad, "sink");
		g_assert (targetsink != NULL);
		gst_pad_link (pad, targetsink);
		gst_object_unref (targetsink);
	}

	gst_caps_unref (caps);
}

static gboolean
bus_call (GstBus     *bus,
           GstMessage *msg,
           gpointer    data)
{
	GMainLoop *loop = (GMainLoop *) data;

	switch (GST_MESSAGE_TYPE (msg)) {
		case GST_MESSAGE_EOS:
			g_print ("End of stream\n");
			g_main_loop_quit (loop);
			break;
		case GST_MESSAGE_ERROR: {
			gchar  *debug;
			GError *error;

			gst_message_parse_error (msg, &error, &debug);
			g_free (debug);

			g_printerr ("Error: %s\n", error->message);
			g_error_free (error);

			g_main_loop_quit (loop);
			break;
		}
		default:
			break;
	}

	return TRUE;
}

int
main (int   argc,
       char *argv[])
{
	GMainLoop *loop;

	GstElement *pipeline;
	GstBus *bus;

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

	loop = g_main_loop_new (NULL, FALSE);


	/* Check input arguments */
	if (argc != 2) {
		g_printerr ("Usage: %s <Video H264 filename>\n", argv[0]);
		return -1;
	}

	/* Create gstreamer elements */
	pipeline	= gst_pipeline_new ("media-player");
	source		= gst_element_factory_make ("filesrc","file-source");
	demuxer		= gst_element_factory_make ("avidemux","avi-demuxer");
	decvd		= gst_element_factory_make ("x170", "video-decoder");
	decad		= gst_element_factory_make ("mad", "mp3-decoder");
	vdsink		= gst_element_factory_make ("ximagesink", "video-sink");
	vdqueue		= gst_element_factory_make ("multiqueue", "video-queue");
	adqueue		= gst_element_factory_make ("multiqueue", "audio-queue");
	adsink		= gst_element_factory_make ("osssink", "audio-sink");

	/* if needed to be set to MPEG4(value 4), default is AUTO */
	//g_object_set (decvd, "codec", 4, NULL);
	/* output format: RGB16 (i.e 2) */
	g_object_set (decvd, "output", 2, NULL);
	/* Scaling value */
	g_object_set (decvd, "scaling", 1.0, NULL);
	/* Threshold of the VDEC to sync audio and video */
	g_object_set (decvd, "inbuf-thresh", 100000, NULL);

	if (!pipeline || !source || !demuxer || !decvd || !vdsink || !vdqueue 
|| !decad || !adqueue || !adsink) {
		g_printerr ("One element could not be created. Exiting.\n");
		return -1;
	}

	/* Set up the pipeline */

	/* we set the input filename to the source element */
	g_object_set (G_OBJECT (source), "location", argv[1], NULL);

	/* we add a message handler */
	bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
	gst_bus_add_watch (bus, bus_call, loop);
	gst_object_unref (bus);

	/* we add all elements into the pipeline */
	/* file-source | avi-demuxer | 	x170-decoder | ximagesink
	 * 			     | mad | audioconvert | osssink*/

	/* demux only */
	gst_bin_add_many (GST_BIN (pipeline),
                     source, demuxer, NULL);

	/* video only */
	gst_bin_add_many (GST_BIN (pipeline),
                     decvd, vdqueue, vdsink, NULL);

	/* audio only */
	gst_bin_add_many (GST_BIN (pipeline),
                     decad, adqueue, adsink, NULL);

	/* we link the elements together */
	/* file-source -> demuxer ~> decoder -> image sink */
	gst_element_link (source, demuxer);
	
	if(!gst_element_link_many(decvd, vdqueue, vdsink, NULL)) {
		printf("problem linking video elements!!!!!\n");
		return FALSE;
	}

	if(!gst_element_link_many( decad, adqueue, adsink, NULL)) {
		printf("problem linking audio elements!!!!!\n");
		return FALSE;
	}

	gst_element_link_pads (demuxer, "video", vdqueue, "sink");
	gst_element_link_pads (demuxer, "audio", adqueue, "sink");
	
	g_signal_connect (demuxer, "pad-added", G_CALLBACK (on_pad_added), NULL);

	/* note that the demuxer will be linked to the decoder dynamically.
	The reason is that Ogg may contain various streams (for example
	audio and video). The source pad(s) will be created at run time,
	by the demuxer when it detects the amount and nature of streams.
	Therefore we connect a callback function which will be executed
	when the "pad-added" is emitted.*/

	/* Set the pipeline to "playing" state*/
	g_print ("Now playing: %s\n", argv[1]);
	gst_element_set_state (pipeline, GST_STATE_PLAYING);


	/* Iterate */
	g_print ("Running...\n");
	g_main_loop_run (loop);


	/* Out of the main loop, clean up nicely */
	g_print ("Returned, stopping playback\n");
	gst_element_set_state (pipeline, GST_STATE_NULL);

	g_print ("Deleting pipeline\n");
	gst_object_unref (GST_OBJECT (pipeline));

	return 0;
}