1 /*
2 * text-color-example.c
3 *
4 * Builds a pipeline with [videotestsrc ! textoverlay ! ximagesink] and
5 * moves text
6 *
7 * Needs gst-plugins-base installed.
8 */
9
10 #include <gst/gst.h>
11 #include <gst/controller/gstinterpolationcontrolsource.h>
12 #include <gst/controller/gstlfocontrolsource.h>
13 #include <gst/controller/gstargbcontrolbinding.h>
14 #include <gst/controller/gstdirectcontrolbinding.h>
15
16 gint
main(gint argc,gchar ** argv)17 main (gint argc, gchar ** argv)
18 {
19 gint res = 1;
20 GstElement *src, *text, *sink;
21 GstElement *bin;
22 GstControlSource *cs;
23 GstClock *clock;
24 GstClockID clock_id;
25 GstClockReturn wait_ret;
26
27 gst_init (&argc, &argv);
28
29 /* build pipeline */
30 bin = gst_pipeline_new ("pipeline");
31 clock = gst_pipeline_get_clock (GST_PIPELINE (bin));
32 src = gst_element_factory_make ("videotestsrc", NULL);
33 if (!src) {
34 GST_WARNING ("need videotestsrc from gst-plugins-base");
35 goto Error;
36 }
37 g_object_set (src, "pattern", /* red */ 4,
38 NULL);
39 text = gst_element_factory_make ("textoverlay", NULL);
40 if (!text) {
41 GST_WARNING ("need textoverlay from gst-plugins-base");
42 goto Error;
43 }
44 g_object_set (text,
45 "text", "GStreamer rocks!",
46 "font-desc", "Sans, 30",
47 "xpos", 0.0, "wrap-mode", -1, "halignment", /* position */ 4,
48 "valignment", /* position */ 3,
49 NULL);
50 sink = gst_element_factory_make ("ximagesink", NULL);
51 if (!sink) {
52 GST_WARNING ("need ximagesink from gst-plugins-base");
53 goto Error;
54 }
55
56 gst_bin_add_many (GST_BIN (bin), src, text, sink, NULL);
57 if (!gst_element_link_many (src, text, sink, NULL)) {
58 GST_WARNING ("can't link elements");
59 goto Error;
60 }
61
62 /* setup control sources */
63 cs = gst_interpolation_control_source_new ();
64 gst_object_add_control_binding (GST_OBJECT_CAST (text),
65 gst_direct_control_binding_new_absolute (GST_OBJECT_CAST (text), "deltax",
66 cs));
67
68 g_object_set (cs, "mode", GST_INTERPOLATION_MODE_LINEAR, NULL);
69
70 // At second 0 the text will be at 0px on the x-axis
71 gst_timed_value_control_source_set ((GstTimedValueControlSource *) cs, 0, 0);
72 // At second 5 the text will be at 1000px on the x-axis
73 gst_timed_value_control_source_set ((GstTimedValueControlSource *) cs,
74 GST_SECOND * 5, 1000);
75
76 gst_object_unref (cs);
77
78 /* run for 10 seconds */
79 clock_id =
80 gst_clock_new_single_shot_id (clock,
81 gst_clock_get_time (clock) + (10 * GST_SECOND));
82
83 if (gst_element_set_state (bin, GST_STATE_PLAYING)) {
84 if ((wait_ret = gst_clock_id_wait (clock_id, NULL)) != GST_CLOCK_OK) {
85 GST_WARNING ("clock_id_wait returned: %d", wait_ret);
86 }
87 gst_element_set_state (bin, GST_STATE_NULL);
88 }
89
90 /* cleanup */
91 gst_clock_id_unref (clock_id);
92 gst_object_unref (G_OBJECT (clock));
93 gst_object_unref (G_OBJECT (bin));
94 res = 0;
95 Error:
96 return (res);
97 }
98