tests/examples/dynamic/codec-select.c - mtk-gst-plugins-base - Git at Google

 /* GStreamer
  *
  * codec-select.c: sample application to dynamically select a codec
  *
  * Copyright (C) <2008> Wim Taymans <wim dot taymans at gmail dot com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public
  * License along with this library; if not, write to the
  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */

 /*
  * This example sets up a pipeline to 'encode' an audiotestsrc into 3 different
  * formats. The format can be selected dynamically at runtime.
  *
  * Each of the encoders require the audio in a specific different format.
  *
  * This example uses identity as the encoder and enforces the caps on identity
  * with a capsfilter.
  *
  * This is a good example of input and output selector and how these elements
  * preserve segment and timing information while switching between streams.
  */

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

 /* Create an encoder element.
  * We make a bin containing:
  *
  * audioresample ! <enccaps> ! identity
  *
  * The sinkpad of audioresample and source pad of identity are ghosted on the
  * bin.
  */
 static GstElement *
 make_encoder (const GstCaps * caps)
 {
   GstElement *result;
   GstElement *audioresample;
   GstElement *capsfilter;
   GstElement *identity;
   GstPad *pad;

   /* create result bin */
   result = gst_bin_new (NULL);
   g_assert (result);

   /* create elements */
   audioresample = gst_element_factory_make ("audioresample", NULL);
   g_assert (audioresample);

   capsfilter = gst_element_factory_make ("capsfilter", NULL);
   g_assert (capsfilter);
   g_object_set (capsfilter, "caps", caps, NULL);

   identity = gst_element_factory_make ("identity", NULL);
   g_assert (identity);
   g_object_set (identity, "silent", TRUE, NULL);

   /* add elements to result bin */
   gst_bin_add (GST_BIN (result), audioresample);
   gst_bin_add (GST_BIN (result), capsfilter);
   gst_bin_add (GST_BIN (result), identity);

   /* link elements */
   gst_element_link_pads (audioresample, "src", capsfilter, "sink");
   gst_element_link_pads (capsfilter, "src", identity, "sink");

   /* ghost src and sink pads */
   pad = gst_element_get_static_pad (audioresample, "sink");
   gst_element_add_pad (result, gst_ghost_pad_new ("sink", pad));
   gst_object_unref (pad);

   pad = gst_element_get_static_pad (identity, "src");
   gst_element_add_pad (result, gst_ghost_pad_new ("src", pad));
   gst_object_unref (pad);

   return result;
 }

 /*
  * We generate:
  *
  * audiotestsrc ! <audiocaps> ! output-selector ! [enc1 .. enc3] ! input-selector
  * select-all = true ! fakesink
  *
  * <audiocaps> makes sure we only produce one format from the audiotestsrc.
  *
  * Each encX element consists of:
  *
  *  audioresample ! <enccaps> ! identity !
  *
  * This way we can simply switch encoders without having to renegotiate.
  */
 static GstElement *
 make_pipeline (void)
 {
   GstElement *result;
   GstElement *audiotestsrc;
   GstElement *audiocaps;
   GstElement *outputselect;
   GstElement *inputselect;
   GstElement *sink;
   GstCaps *caps;
   GstCaps *capslist[3];
   gint i;

   /* create result pipeline */
   result = gst_pipeline_new (NULL);
   g_assert (result);

   /* create various elements */
   audiotestsrc = gst_element_factory_make ("audiotestsrc", NULL);
   g_object_set (audiotestsrc, "num-buffers", 1000, NULL);
   g_assert (audiotestsrc);

   audiocaps = gst_element_factory_make ("capsfilter", NULL);
   g_assert (audiocaps);

   caps =
       gst_caps_from_string ("audio/x-raw,format=S16LE,rate=48000,channels=1");
   g_object_set (audiocaps, "caps", caps, NULL);
   gst_caps_unref (caps);

   outputselect = gst_element_factory_make ("output-selector", "select");
   g_assert (outputselect);

   inputselect = gst_element_factory_make ("input-selector", NULL);
   g_assert (inputselect);
   g_object_set (inputselect, "select-all", TRUE, NULL);

   sink = gst_element_factory_make ("fakesink", NULL);
   g_object_set (sink, "sync", TRUE, NULL);
   g_object_set (sink, "silent", TRUE, NULL);
   g_assert (sink);

   /* add elements */
   gst_bin_add (GST_BIN (result), audiotestsrc);
   gst_bin_add (GST_BIN (result), audiocaps);
   gst_bin_add (GST_BIN (result), outputselect);
   gst_bin_add (GST_BIN (result), inputselect);
   gst_bin_add (GST_BIN (result), sink);

   /* link elements */
   gst_element_link_pads (audiotestsrc, "src", audiocaps, "sink");
   gst_element_link_pads (audiocaps, "src", outputselect, "sink");
   gst_element_link_pads (inputselect, "src", sink, "sink");

   /* make caps */
   capslist[0] =
       gst_caps_from_string ("audio/x-raw,format=S16LE,rate=48000,channels=1");
   capslist[1] =
       gst_caps_from_string ("audio/x-raw,format=S16LE,rate=16000,channels=1");
   capslist[2] =
       gst_caps_from_string ("audio/x-raw,format=S16LE,rate=8000,channels=1");

   /* create encoder elements */
   for (i = 0; i < 3; i++) {
     GstElement *encoder;
     GstPad *srcpad, *sinkpad;

     encoder = make_encoder (capslist[i]);
     g_assert (encoder);

     gst_bin_add (GST_BIN (result), encoder);

     srcpad = gst_element_get_request_pad (outputselect, "src_%u");
     sinkpad = gst_element_get_static_pad (encoder, "sink");
     gst_pad_link (srcpad, sinkpad);
     gst_object_unref (srcpad);
     gst_object_unref (sinkpad);

     srcpad = gst_element_get_static_pad (encoder, "src");
     sinkpad = gst_element_get_request_pad (inputselect, "sink_%u");
     gst_pad_link (srcpad, sinkpad);
     gst_object_unref (srcpad);
     gst_object_unref (sinkpad);
   }

   return result;
 }

 static gboolean
 do_switch (GstElement * pipeline)
 {
   gint rand;
   GstElement *select;
   gchar *name;
   GstPad *pad;

   rand = g_random_int_range (0, 3);

   g_print ("switching to %d\n", rand);

   /* find the selector */
   select = gst_bin_get_by_name (GST_BIN (pipeline), "select");

   /* get the named pad */
   name = g_strdup_printf ("src_%u", rand);
   pad = gst_element_get_static_pad (select, name);
   g_free (name);

   /* set the active pad */
   g_object_set (select, "active-pad", pad, NULL);
   gst_object_unref (select);

   return TRUE;
 }

 static gboolean
 my_bus_callback (GstBus * bus, GstMessage * message, gpointer data)
 {
   GstElement *sender = (GstElement *) GST_MESSAGE_SRC (message);
   gchar *name = gst_element_get_name (sender);
   GMainLoop *loop = (GMainLoop *) data;

   g_print ("Got %s message from %s\n", GST_MESSAGE_TYPE_NAME (message), name);
   g_free (name);

   switch (GST_MESSAGE_TYPE (message)) {

     case GST_MESSAGE_ERROR:{
       GError *err;
       gchar *debug;

       gst_message_parse_error (message, &err, &debug);
       g_print ("Error: %s (%s)\n", err->message, debug);
       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;
   }

   return TRUE;
 }

 gint
 main (gint argc, gchar * argv[])
 {
   GstElement *pipeline;
   GstBus *bus;
   GMainLoop *loop;

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

   /* set up */
   pipeline = make_pipeline ();

   g_signal_connect (pipeline, "deep_notify",
       G_CALLBACK (gst_object_default_deep_notify), NULL);

   bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
   gst_bus_add_watch (bus, my_bus_callback, loop);
   gst_object_unref (bus);

   g_print ("Starting pipeline\n");

   gst_element_set_state (pipeline, GST_STATE_PLAYING);

   /* add a timeout to cycle between the formats */
   g_timeout_add_seconds (1, (GSourceFunc) do_switch, pipeline);

   /* now run */
   g_main_loop_run (loop);

   g_print ("Nulling pipeline\n");

   /* also clean up */
   gst_element_set_state (pipeline, GST_STATE_NULL);
   gst_object_unref (pipeline);

   return 0;
 }
	/* GStreamer
	*
	* codec-select.c: sample application to dynamically select a codec
	*
	* Copyright (C) <2008> Wim Taymans <wim dot taymans at gmail dot com>
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Library General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Library General Public License for more details.
	*
	* You should have received a copy of the GNU Library General Public
	* License along with this library; if not, write to the
	* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
	* Boston, MA 02110-1301, USA.
	*/

	/*
	* This example sets up a pipeline to 'encode' an audiotestsrc into 3 different
	* formats. The format can be selected dynamically at runtime.
	*
	* Each of the encoders require the audio in a specific different format.
	*
	* This example uses identity as the encoder and enforces the caps on identity
	* with a capsfilter.
	*
	* This is a good example of input and output selector and how these elements
	* preserve segment and timing information while switching between streams.
	*/

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

	/* Create an encoder element.
	* We make a bin containing:
	*
	* audioresample ! <enccaps> ! identity
	*
	* The sinkpad of audioresample and source pad of identity are ghosted on the
	* bin.
	*/
	static GstElement *
	make_encoder (const GstCaps * caps)
	{
	GstElement *result;
	GstElement *audioresample;
	GstElement *capsfilter;
	GstElement *identity;
	GstPad *pad;

	/* create result bin */
	result = gst_bin_new (NULL);
	g_assert (result);

	/* create elements */
	audioresample = gst_element_factory_make ("audioresample", NULL);
	g_assert (audioresample);

	capsfilter = gst_element_factory_make ("capsfilter", NULL);
	g_assert (capsfilter);
	g_object_set (capsfilter, "caps", caps, NULL);

	identity = gst_element_factory_make ("identity", NULL);
	g_assert (identity);
	g_object_set (identity, "silent", TRUE, NULL);

	/* add elements to result bin */
	gst_bin_add (GST_BIN (result), audioresample);
	gst_bin_add (GST_BIN (result), capsfilter);
	gst_bin_add (GST_BIN (result), identity);

	/* link elements */
	gst_element_link_pads (audioresample, "src", capsfilter, "sink");
	gst_element_link_pads (capsfilter, "src", identity, "sink");

	/* ghost src and sink pads */
	pad = gst_element_get_static_pad (audioresample, "sink");
	gst_element_add_pad (result, gst_ghost_pad_new ("sink", pad));
	gst_object_unref (pad);

	pad = gst_element_get_static_pad (identity, "src");
	gst_element_add_pad (result, gst_ghost_pad_new ("src", pad));
	gst_object_unref (pad);

	return result;
	}

	/*
	* We generate:
	*
	* audiotestsrc ! <audiocaps> ! output-selector ! [enc1 .. enc3] ! input-selector
	* select-all = true ! fakesink
	*
	* <audiocaps> makes sure we only produce one format from the audiotestsrc.
	*
	* Each encX element consists of:
	*
	* audioresample ! <enccaps> ! identity !
	*
	* This way we can simply switch encoders without having to renegotiate.
	*/
	static GstElement *
	make_pipeline (void)
	{
	GstElement *result;
	GstElement *audiotestsrc;
	GstElement *audiocaps;
	GstElement *outputselect;
	GstElement *inputselect;
	GstElement *sink;
	GstCaps *caps;
	GstCaps *capslist[3];
	gint i;

	/* create result pipeline */
	result = gst_pipeline_new (NULL);
	g_assert (result);

	/* create various elements */
	audiotestsrc = gst_element_factory_make ("audiotestsrc", NULL);
	g_object_set (audiotestsrc, "num-buffers", 1000, NULL);
	g_assert (audiotestsrc);

	audiocaps = gst_element_factory_make ("capsfilter", NULL);
	g_assert (audiocaps);

	caps =
	gst_caps_from_string ("audio/x-raw,format=S16LE,rate=48000,channels=1");
	g_object_set (audiocaps, "caps", caps, NULL);
	gst_caps_unref (caps);

	outputselect = gst_element_factory_make ("output-selector", "select");
	g_assert (outputselect);

	inputselect = gst_element_factory_make ("input-selector", NULL);
	g_assert (inputselect);
	g_object_set (inputselect, "select-all", TRUE, NULL);

	sink = gst_element_factory_make ("fakesink", NULL);
	g_object_set (sink, "sync", TRUE, NULL);
	g_object_set (sink, "silent", TRUE, NULL);
	g_assert (sink);

	/* add elements */
	gst_bin_add (GST_BIN (result), audiotestsrc);
	gst_bin_add (GST_BIN (result), audiocaps);
	gst_bin_add (GST_BIN (result), outputselect);
	gst_bin_add (GST_BIN (result), inputselect);
	gst_bin_add (GST_BIN (result), sink);

	/* link elements */
	gst_element_link_pads (audiotestsrc, "src", audiocaps, "sink");
	gst_element_link_pads (audiocaps, "src", outputselect, "sink");
	gst_element_link_pads (inputselect, "src", sink, "sink");

	/* make caps */
	capslist[0] =
	gst_caps_from_string ("audio/x-raw,format=S16LE,rate=48000,channels=1");
	capslist[1] =
	gst_caps_from_string ("audio/x-raw,format=S16LE,rate=16000,channels=1");
	capslist[2] =
	gst_caps_from_string ("audio/x-raw,format=S16LE,rate=8000,channels=1");

	/* create encoder elements */
	for (i = 0; i < 3; i++) {
	GstElement *encoder;
	GstPad srcpad, sinkpad;

	encoder = make_encoder (capslist[i]);
	g_assert (encoder);

	gst_bin_add (GST_BIN (result), encoder);

	srcpad = gst_element_get_request_pad (outputselect, "src_%u");
	sinkpad = gst_element_get_static_pad (encoder, "sink");
	gst_pad_link (srcpad, sinkpad);
	gst_object_unref (srcpad);
	gst_object_unref (sinkpad);

	srcpad = gst_element_get_static_pad (encoder, "src");
	sinkpad = gst_element_get_request_pad (inputselect, "sink_%u");
	gst_pad_link (srcpad, sinkpad);
	gst_object_unref (srcpad);
	gst_object_unref (sinkpad);
	}

	return result;
	}

	static gboolean
	do_switch (GstElement * pipeline)
	{
	gint rand;
	GstElement *select;
	gchar *name;
	GstPad *pad;

	rand = g_random_int_range (0, 3);

	g_print ("switching to %d\n", rand);

	/* find the selector */
	select = gst_bin_get_by_name (GST_BIN (pipeline), "select");

	/* get the named pad */
	name = g_strdup_printf ("src_%u", rand);
	pad = gst_element_get_static_pad (select, name);
	g_free (name);

	/* set the active pad */
	g_object_set (select, "active-pad", pad, NULL);
	gst_object_unref (select);

	return TRUE;
	}

	static gboolean
	my_bus_callback (GstBus * bus, GstMessage * message, gpointer data)
	{
	GstElement sender = (GstElement ) GST_MESSAGE_SRC (message);
	gchar *name = gst_element_get_name (sender);
	GMainLoop loop = (GMainLoop ) data;

	g_print ("Got %s message from %s\n", GST_MESSAGE_TYPE_NAME (message), name);
	g_free (name);

	switch (GST_MESSAGE_TYPE (message)) {

	case GST_MESSAGE_ERROR:{
	GError *err;
	gchar *debug;

	gst_message_parse_error (message, &err, &debug);
	g_print ("Error: %s (%s)\n", err->message, debug);
	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;
	}

	return TRUE;
	}

	gint
	main (gint argc, gchar * argv[])
	{
	GstElement *pipeline;
	GstBus *bus;
	GMainLoop *loop;

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

	/* set up */
	pipeline = make_pipeline ();

	g_signal_connect (pipeline, "deep_notify",
	G_CALLBACK (gst_object_default_deep_notify), NULL);

	bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
	gst_bus_add_watch (bus, my_bus_callback, loop);
	gst_object_unref (bus);

	g_print ("Starting pipeline\n");

	gst_element_set_state (pipeline, GST_STATE_PLAYING);

	/* add a timeout to cycle between the formats */
	g_timeout_add_seconds (1, (GSourceFunc) do_switch, pipeline);

	/* now run */
	g_main_loop_run (loop);

	g_print ("Nulling pipeline\n");

	/* also clean up */
	gst_element_set_state (pipeline, GST_STATE_NULL);
	gst_object_unref (pipeline);

	return 0;
	}