1/* GStreamer
2 *
3 * Copyright (C) 2007 Sebastian Dröge <slomo@circular-chaos.org>
4 *
5 * gstcontrolsource.h: Interface declaration for control sources
6 *
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
16 *
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
20 * Boston, MA 02110-1301, USA.
21 */
22
23#ifndef __GST_CONTROL_SOURCE_H__
24#define __GST_CONTROL_SOURCE_H__
25
26#include <gst/gstconfig.h>
27
28#include <glib-object.h>
29
30#include <gst/gstclock.h>
31
32G_BEGIN_DECLS
33
34#define GST_TYPE_CONTROL_SOURCE \
35 (gst_control_source_get_type())
36#define GST_CONTROL_SOURCE(obj) \
37 (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_CONTROL_SOURCE,GstControlSource))
38#define GST_CONTROL_SOURCE_CLASS(klass) \
39 (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_CONTROL_SOURCE,GstControlSourceClass))
40#define GST_IS_CONTROL_SOURCE(obj) \
41 (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_CONTROL_SOURCE))
42#define GST_IS_CONTROL_SOURCE_CLASS(klass) \
43 (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_CONTROL_SOURCE))
44#define GST_CONTROL_SOURCE_GET_CLASS(obj) \
45 (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_CONTOL_SOURCE, GstControlSourceClass))
46
47typedef struct _GstControlSource GstControlSource;
48typedef struct _GstControlSourceClass GstControlSourceClass;
49typedef struct _GstTimedValue GstTimedValue;
50typedef struct _GstValueArray GstValueArray;
51
52/**
53 * GstTimedValue:
54 * @timestamp: timestamp of the value change
55 * @value: the corresponding value
56 *
57 * Structure for storing a timestamp and a value.
58 */
59struct _GstTimedValue
60{
61 GstClockTime timestamp;
62 gdouble value;
63};
64
65/**
66 * GstControlSourceGetValue:
67 * @self: the #GstControlSource instance
68 * @timestamp: timestamp for which a value should be calculated
69 * @value: a value which will be set to the result.
70 *
71 * Function for returning a value for a given timestamp.
72 *
73 * Returns: %TRUE if the value was successfully calculated.
74 *
75 */
76typedef gboolean (* GstControlSourceGetValue) (GstControlSource *self,
77 GstClockTime timestamp, gdouble *value);
78
79/**
80 * GstControlSourceGetValueArray:
81 * @self: the #GstControlSource instance
82 * @timestamp: timestamp for which a value should be calculated
83 * @interval: the time spacing between subsequent values
84 * @n_values: the number of values
85 * @values: array to put control-values in
86 *
87 * Function for returning an array of values starting at a given timestamp.
88 *
89 * Returns: %TRUE if the values were successfully calculated.
90 *
91 */
92typedef gboolean (* GstControlSourceGetValueArray) (GstControlSource *self,
93 GstClockTime timestamp, GstClockTime interval, guint n_values, gdouble *values);
94
95/**
96 * GstControlSource:
97 * @parent: the parent structure
98 * @get_value: Function for returning a value for a given timestamp
99 * @get_value_array: Function for returning a values array for a given timestamp
100 *
101 * The instance structure of #GstControlSource.
102 */
103struct _GstControlSource {
104 GstObject parent;
105
106 /*< public >*/
107 GstControlSourceGetValue get_value; /* Returns the value for a property at a given timestamp */
108 GstControlSourceGetValueArray get_value_array; /* Returns values for a property in a given timespan */
109
110 /*< private >*/
111 gpointer _gst_reserved[GST_PADDING];
112};
113
114/**
115 * GstControlSourceClass:
116 * @parent_class: Parent class
117 *
118 * The class structure of #GstControlSource.
119 */
120
121struct _GstControlSourceClass
122{
123 GstObjectClass parent_class;
124
125 /*< private >*/
126 gpointer _gst_reserved[GST_PADDING];
127};
128
129GST_API
130GType gst_control_source_get_type (void);
131
132/* Functions */
133
134GST_API
135gboolean gst_control_source_get_value (GstControlSource *self, GstClockTime timestamp,
136 gdouble *value);
137GST_API
138gboolean gst_control_source_get_value_array (GstControlSource *self, GstClockTime timestamp,
139 GstClockTime interval, guint n_values,
140 gdouble *values);
141G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstControlSource, gst_object_unref)
142
143G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstValueArray, gst_object_unref)
144
145G_END_DECLS
146
147#endif /* __GST_CONTROL_SOURCE_H__ */
148

source code of include/gstreamer-1.0/gst/gstcontrolsource.h