1 /* GStreamer
2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wim.taymans@chello.be>
4 * 2005 Wim Taymans <wim@fluendo.com>
5 *
6 * gstquery.h: GstQuery API declaration
7 *
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
17 *
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
22 */
25 #ifndef __GST_QUERY_H__
26 #define __GST_QUERY_H__
28 #include <glib.h>
30 #include <gst/gstiterator.h>
31 #include <gst/gstminiobject.h>
32 #include <gst/gststructure.h>
33 #include <gst/gstformat.h>
35 G_BEGIN_DECLS
37 /**
38 * GstQueryType:
39 * @GST_QUERY_NONE: invalid query type
40 * @GST_QUERY_POSITION: current/end position in stream
41 * @GST_QUERY_LATENCY: latency of stream
42 * @GST_QUERY_JITTER: current jitter of stream
43 * @GST_QUERY_RATE: current rate of the stream
44 * @GST_QUERY_SEEKING: seeking capabilities
45 * @GST_QUERY_SEGMENT: segment start/stop positions
46 * @GST_QUERY_CONVERT: convert values
47 * @GST_QUERY_FORMATS: query supported formats for convert
48 *
49 * Standard predefined Query types
50 */
51 typedef enum {
52 GST_QUERY_NONE = 0,
53 GST_QUERY_POSITION,
54 GST_QUERY_LATENCY,
55 GST_QUERY_JITTER, /* not in draft-query, necessary? */
56 GST_QUERY_RATE,
57 GST_QUERY_SEEKING,
58 GST_QUERY_SEGMENT,
59 GST_QUERY_CONVERT,
60 GST_QUERY_FORMATS
61 } GstQueryType;
63 /**
64 * GST_QUERY_TYPE_RATE_DEN:
65 *
66 * Rates are relative to this value
67 */
68 #define GST_QUERY_TYPE_RATE_DEN G_GINT64_CONSTANT (1000000)
70 typedef struct _GstQueryTypeDefinition GstQueryTypeDefinition;
71 typedef struct _GstQuery GstQuery;
72 typedef struct _GstQueryClass GstQueryClass;
74 /**
75 * GstQueryTypeDefinition:
76 * @value: the unique id of the Query type
77 * @nick: a short nick
78 * @description: a longer description of the query type
79 *
80 * A Query Type definition
81 */
82 struct _GstQueryTypeDefinition
83 {
84 GstQueryType value;
85 gchar *nick;
86 gchar *description;
87 };
89 #define GST_TYPE_QUERY (gst_query_get_type())
90 #define GST_IS_QUERY(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_QUERY))
91 #define GST_IS_QUERY_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_QUERY))
92 #define GST_QUERY_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_QUERY, GstQueryClass))
93 #define GST_QUERY(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_QUERY, GstQuery))
94 #define GST_QUERY_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_QUERY, GstQueryClass))
96 #define GST_QUERY_TYPE(query) (((GstQuery*)(query))->type)
98 struct _GstQuery
99 {
100 GstMiniObject mini_object;
102 /*< public > */
103 GstQueryType type;
105 GstStructure *structure;
107 /*< private > */
108 gpointer _gst_reserved[GST_PADDING];
109 };
111 struct _GstQueryClass {
112 GstMiniObjectClass mini_object_class;
114 /*< private > */
115 gpointer _gst_reserved[GST_PADDING];
116 };
118 void _gst_query_initialize (void);
119 GType gst_query_get_type (void);
121 /* register a new query */
122 GstQueryType gst_query_type_register (const gchar *nick,
123 const gchar *description);
124 GstQueryType gst_query_type_get_by_nick (const gchar *nick);
126 /* check if a query is in an array of querys */
127 gboolean gst_query_types_contains (const GstQueryType *types,
128 GstQueryType type);
130 /* query for query details */
132 G_CONST_RETURN GstQueryTypeDefinition*
133 gst_query_type_get_details (GstQueryType type);
134 GstIterator* gst_query_type_iterate_definitions (void);
136 /* refcounting */
137 #define gst_query_ref(msg) GST_QUERY (gst_mini_object_ref (GST_MINI_OBJECT (msg)))
138 #define gst_query_unref(msg) gst_mini_object_unref (GST_MINI_OBJECT (msg))
139 /* copy query */
140 #define gst_query_copy(msg) GST_QUERY (gst_mini_object_copy (GST_MINI_OBJECT (msg)))
141 #define gst_query_make_writable(msg) GST_QUERY (gst_mini_object_make_writable (GST_MINI_OBJECT (msg)))
143 /* position query */
144 GstQuery* gst_query_new_position (GstFormat format);
145 void gst_query_set_position (GstQuery *query, GstFormat format,
146 gint64 cur, gint64 end);
147 void gst_query_parse_position (GstQuery *query, GstFormat *format,
148 gint64 *cur, gint64 *end);
149 /* convert query */
150 GstQuery* gst_query_new_convert (GstFormat src_fmt, gint64 value, GstFormat dest_fmt);
151 void gst_query_set_convert (GstQuery *query, GstFormat src_format, gint64 src_value,
152 GstFormat dest_format, gint64 dest_value);
153 void gst_query_parse_convert (GstQuery *query, GstFormat *src_format, gint64 *src_value,
154 GstFormat *dest_format, gint64 *dest_value);
155 /* segment query */
156 GstQuery* gst_query_new_segment (GstFormat format);
157 void gst_query_set_segment (GstQuery *query, gdouble rate, GstFormat format,
158 gint64 start_value, gint64 stop_value, gint64 base);
159 void gst_query_parse_segment (GstQuery *query, gdouble *rate, GstFormat *format,
160 gint64 *start_value, gint64 *stop_value, gint64 *base);
163 /* application specific query */
164 GstQuery * gst_query_new_application (GstQueryType type,
165 GstStructure *structure);
168 GstStructure * gst_query_get_structure (GstQuery *query);
170 G_END_DECLS
172 #endif /* __GST_QUERY_H__ */