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 * gstformat.c: GstFormat registration
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., 51 Franklin St, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
22 */
23
24 /**
25 * SECTION:gstformat
26 * @title: GstFormat
27 * @short_description: Dynamically register new data formats
28 * @see_also: #GstPad, #GstElement
29 *
30 * GstFormats functions are used to register a new format to the gstreamer
31 * core. Formats can be used to perform seeking or conversions/query
32 * operations.
33 */
34
35
36 #include "gst_private.h"
37 #include <string.h>
38 #include "gstformat.h"
39 #include "gstenumtypes.h"
40
41 static GMutex mutex;
42 static GList *_gst_formats = NULL;
43 static GHashTable *_nick_to_format = NULL;
44 static GHashTable *_format_to_nick = NULL;
45 static guint32 _n_values = 1; /* we start from 1 because 0 reserved for UNDEFINED */
46
47 static GstFormatDefinition standard_definitions[] = {
48 {GST_FORMAT_DEFAULT, "default", "Default format for the media type", 0},
49 {GST_FORMAT_BYTES, "bytes", "Bytes", 0},
50 {GST_FORMAT_TIME, "time", "Time", 0},
51 {GST_FORMAT_BUFFERS, "buffers", "Buffers", 0},
52 {GST_FORMAT_PERCENT, "percent", "Percent", 0},
53 {GST_FORMAT_UNDEFINED, NULL, NULL, 0}
54 };
55
56 void
_priv_gst_format_initialize(void)57 _priv_gst_format_initialize (void)
58 {
59 GstFormatDefinition *standards = standard_definitions;
60
61 g_mutex_lock (&mutex);
62 if (_nick_to_format == NULL) {
63 _nick_to_format = g_hash_table_new (g_str_hash, g_str_equal);
64 _format_to_nick = g_hash_table_new (NULL, NULL);
65 }
66
67 while (standards->nick) {
68 standards->quark = g_quark_from_static_string (standards->nick);
69 g_hash_table_insert (_nick_to_format, (gpointer) standards->nick,
70 standards);
71 g_hash_table_insert (_format_to_nick, GINT_TO_POINTER (standards->value),
72 standards);
73
74 _gst_formats = g_list_append (_gst_formats, standards);
75 standards++;
76 _n_values++;
77 }
78 /* getting the type registers the enum */
79 g_type_class_ref (gst_format_get_type ());
80 g_mutex_unlock (&mutex);
81 }
82
83 /**
84 * gst_format_get_name:
85 * @format: a #GstFormat
86 *
87 * Get a printable name for the given format. Do not modify or free.
88 *
89 * Returns: (nullable): a reference to the static name of the format
90 * or %NULL if the format is unknown.
91 */
92 const gchar *
gst_format_get_name(GstFormat format)93 gst_format_get_name (GstFormat format)
94 {
95 const GstFormatDefinition *def;
96 const gchar *result;
97
98 if ((def = gst_format_get_details (format)) != NULL)
99 result = def->nick;
100 else
101 result = NULL;
102
103 return result;
104 }
105
106 /**
107 * gst_format_to_quark:
108 * @format: a #GstFormat
109 *
110 * Get the unique quark for the given format.
111 *
112 * Returns: the quark associated with the format or 0 if the format
113 * is unknown.
114 */
115 GQuark
gst_format_to_quark(GstFormat format)116 gst_format_to_quark (GstFormat format)
117 {
118 const GstFormatDefinition *def;
119 GQuark result;
120
121 if ((def = gst_format_get_details (format)) != NULL)
122 result = def->quark;
123 else
124 result = 0;
125
126 return result;
127 }
128
129 /**
130 * gst_format_register:
131 * @nick: The nick of the new format
132 * @description: The description of the new format
133 *
134 * Create a new GstFormat based on the nick or return an
135 * already registered format with that nick.
136 *
137 * Returns: A new GstFormat or an already registered format
138 * with the same nick.
139 *
140 * MT safe.
141 */
142 GstFormat
gst_format_register(const gchar * nick,const gchar * description)143 gst_format_register (const gchar * nick, const gchar * description)
144 {
145 GstFormatDefinition *format;
146 GstFormat query;
147
148 g_return_val_if_fail (nick != NULL, GST_FORMAT_UNDEFINED);
149 g_return_val_if_fail (description != NULL, GST_FORMAT_UNDEFINED);
150
151 query = gst_format_get_by_nick (nick);
152 if (query != GST_FORMAT_UNDEFINED)
153 return query;
154
155 g_mutex_lock (&mutex);
156 format = g_slice_new (GstFormatDefinition);
157 format->value = (GstFormat) _n_values;
158 format->nick = g_strdup (nick);
159 format->description = g_strdup (description);
160 format->quark = g_quark_from_static_string (format->nick);
161
162 g_hash_table_insert (_nick_to_format, (gpointer) format->nick, format);
163 g_hash_table_insert (_format_to_nick, GINT_TO_POINTER (format->value),
164 format);
165 _gst_formats = g_list_append (_gst_formats, format);
166 _n_values++;
167 g_mutex_unlock (&mutex);
168
169 return format->value;
170 }
171
172 /**
173 * gst_format_get_by_nick:
174 * @nick: The nick of the format
175 *
176 * Return the format registered with the given nick.
177 *
178 * Returns: The format with @nick or GST_FORMAT_UNDEFINED
179 * if the format was not registered.
180 */
181 GstFormat
gst_format_get_by_nick(const gchar * nick)182 gst_format_get_by_nick (const gchar * nick)
183 {
184 GstFormatDefinition *format;
185
186 g_return_val_if_fail (nick != NULL, GST_FORMAT_UNDEFINED);
187
188 g_mutex_lock (&mutex);
189 format = g_hash_table_lookup (_nick_to_format, nick);
190 g_mutex_unlock (&mutex);
191
192 if (format != NULL)
193 return format->value;
194 else
195 return GST_FORMAT_UNDEFINED;
196 }
197
198 /**
199 * gst_formats_contains:
200 * @formats: (array zero-terminated=1): The format array to search
201 * @format: the format to find
202 *
203 * See if the given format is inside the format array.
204 *
205 * Returns: %TRUE if the format is found inside the array
206 */
207 gboolean
gst_formats_contains(const GstFormat * formats,GstFormat format)208 gst_formats_contains (const GstFormat * formats, GstFormat format)
209 {
210 if (!formats)
211 return FALSE;
212
213 while (*formats) {
214 if (*formats == format)
215 return TRUE;
216
217 formats++;
218 }
219 return FALSE;
220 }
221
222
223 /**
224 * gst_format_get_details:
225 * @format: The format to get details of
226 *
227 * Get details about the given format.
228 *
229 * Returns: (nullable): The #GstFormatDefinition for @format or %NULL
230 * on failure.
231 *
232 * MT safe.
233 */
234 const GstFormatDefinition *
gst_format_get_details(GstFormat format)235 gst_format_get_details (GstFormat format)
236 {
237 const GstFormatDefinition *result;
238
239 g_mutex_lock (&mutex);
240 result = g_hash_table_lookup (_format_to_nick, GINT_TO_POINTER (format));
241 g_mutex_unlock (&mutex);
242
243 return result;
244 }
245
246 /**
247 * gst_format_iterate_definitions:
248 *
249 * Iterate all the registered formats. The format definition is read
250 * only.
251 *
252 * Returns: (transfer full): a GstIterator of #GstFormatDefinition.
253 */
254 GstIterator *
gst_format_iterate_definitions(void)255 gst_format_iterate_definitions (void)
256 {
257 GstIterator *result;
258
259 g_mutex_lock (&mutex);
260 /* FIXME: register a boxed type for GstFormatDefinition */
261 result = gst_iterator_new_list (G_TYPE_POINTER,
262 &mutex, &_n_values, &_gst_formats, NULL, NULL);
263 g_mutex_unlock (&mutex);
264
265 return result;
266 }
267