1 #include <gst/gst.h>
2
3 #define SWITCH_TIMEOUT 1
4 #define NUM_VIDEO_BUFFERS 500
5
6 static GMainLoop *loop;
7
8 /* Output selector src pads */
9 static GstPad *osel_src1 = NULL;
10 static GstPad *osel_src2 = NULL;
11
12 static gboolean
my_bus_callback(GstBus * bus,GstMessage * message,gpointer data)13 my_bus_callback (GstBus * bus, GstMessage * message, gpointer data)
14 {
15 g_print ("Got %s message\n", GST_MESSAGE_TYPE_NAME (message));
16
17 switch (GST_MESSAGE_TYPE (message)) {
18 case GST_MESSAGE_ERROR:{
19 GError *err;
20 gchar *debug;
21
22 gst_message_parse_error (message, &err, &debug);
23 g_print ("Error: %s\n", err->message);
24 g_error_free (err);
25 g_free (debug);
26
27 g_main_loop_quit (loop);
28 break;
29 }
30 case GST_MESSAGE_EOS:
31 /* end-of-stream */
32 g_main_loop_quit (loop);
33 break;
34 default:
35 /* unhandled message */
36 break;
37 }
38 /* we want to be notified again the next time there is a message
39 * on the bus, so returning TRUE (FALSE means we want to stop watching
40 * for messages on the bus and our callback should not be called again)
41 */
42 return TRUE;
43 }
44
45 static gboolean
switch_cb(gpointer user_data)46 switch_cb (gpointer user_data)
47 {
48 GstElement *sel = GST_ELEMENT (user_data);
49 GstPad *old_pad, *new_pad = NULL;
50
51 g_object_get (G_OBJECT (sel), "active-pad", &old_pad, NULL);
52
53 if (old_pad == osel_src1)
54 new_pad = osel_src2;
55 else
56 new_pad = osel_src1;
57
58 g_object_set (G_OBJECT (sel), "active-pad", new_pad, NULL);
59
60 g_print ("switched from %s:%s to %s:%s\n", GST_DEBUG_PAD_NAME (old_pad),
61 GST_DEBUG_PAD_NAME (new_pad));
62
63 gst_object_unref (old_pad);
64
65 return TRUE;
66
67 }
68
69 static void
on_bin_element_added(GstBin * bin,GstElement * element,gpointer user_data)70 on_bin_element_added (GstBin * bin, GstElement * element, gpointer user_data)
71 {
72 g_object_set (G_OBJECT (element), "sync", FALSE, "async", FALSE, NULL);
73 }
74
75 gint
main(gint argc,gchar * argv[])76 main (gint argc, gchar * argv[])
77 {
78 GstElement *pipeline, *src, *toverlay, *osel, *sink1, *sink2, *c1, *c2, *c0;
79 GstPad *sinkpad;
80 GstBus *bus;
81
82 /* init GStreamer */
83 gst_init (&argc, &argv);
84 loop = g_main_loop_new (NULL, FALSE);
85
86 /* create elements */
87 pipeline = gst_element_factory_make ("pipeline", "pipeline");
88 src = gst_element_factory_make ("videotestsrc", "src");
89 c0 = gst_element_factory_make ("videoconvert", NULL);
90 toverlay = gst_element_factory_make ("timeoverlay", "timeoverlay");
91 osel = gst_element_factory_make ("output-selector", "osel");
92 c1 = gst_element_factory_make ("videoconvert", NULL);
93 c2 = gst_element_factory_make ("videoconvert", NULL);
94 sink1 = gst_element_factory_make ("autovideosink", "sink1");
95 sink2 = gst_element_factory_make ("autovideosink", "sink2");
96
97 if (!pipeline || !src || !c0 || !toverlay || !osel || !c1 || !c2 || !sink1 ||
98 !sink2) {
99 g_print ("missing element\n");
100 return -1;
101 }
102
103 /* add them to bin */
104 gst_bin_add_many (GST_BIN (pipeline), src, c0, toverlay, osel, c1, sink1, c2,
105 sink2, NULL);
106
107 /* set properties */
108 g_object_set (G_OBJECT (src), "is-live", TRUE, NULL);
109 g_object_set (G_OBJECT (src), "do-timestamp", TRUE, NULL);
110 g_object_set (G_OBJECT (src), "num-buffers", NUM_VIDEO_BUFFERS, NULL);
111 g_object_set (G_OBJECT (osel), "resend-latest", TRUE, NULL);
112
113 /* handle deferred properties */
114 g_signal_connect (G_OBJECT (sink1), "element-added",
115 G_CALLBACK (on_bin_element_added), NULL);
116 g_signal_connect (G_OBJECT (sink2), "element-added",
117 G_CALLBACK (on_bin_element_added), NULL);
118
119 /* link src ! timeoverlay ! osel */
120 if (!gst_element_link_many (src, c0, toverlay, osel, NULL)) {
121 g_print ("linking failed\n");
122 return -1;
123 }
124
125 /* link output 1 */
126 sinkpad = gst_element_get_static_pad (c1, "sink");
127 osel_src1 = gst_element_get_request_pad (osel, "src_%u");
128 if (gst_pad_link (osel_src1, sinkpad) != GST_PAD_LINK_OK) {
129 g_print ("linking output 1 converter failed\n");
130 return -1;
131 }
132 gst_object_unref (sinkpad);
133
134 if (!gst_element_link (c1, sink1)) {
135 g_print ("linking output 1 failed\n");
136 return -1;
137 }
138
139 /* link output 2 */
140 sinkpad = gst_element_get_static_pad (c2, "sink");
141 osel_src2 = gst_element_get_request_pad (osel, "src_%u");
142 if (gst_pad_link (osel_src2, sinkpad) != GST_PAD_LINK_OK) {
143 g_print ("linking output 2 converter failed\n");
144 return -1;
145 }
146 gst_object_unref (sinkpad);
147
148 if (!gst_element_link (c2, sink2)) {
149 g_print ("linking output 2 failed\n");
150 return -1;
151 }
152
153 /* add switch callback */
154 g_timeout_add_seconds (SWITCH_TIMEOUT, switch_cb, osel);
155
156 /* change to playing */
157 bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
158 gst_bus_add_watch (bus, my_bus_callback, loop);
159 gst_object_unref (bus);
160
161 gst_element_set_state (pipeline, GST_STATE_PLAYING);
162
163 /* now run */
164 g_main_loop_run (loop);
165
166 /* also clean up */
167 gst_element_set_state (pipeline, GST_STATE_NULL);
168 gst_element_release_request_pad (osel, osel_src1);
169 gst_element_release_request_pad (osel, osel_src2);
170 gst_object_unref (GST_OBJECT (pipeline));
171
172 return 0;
173 }
174