2 * Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
4 * gsttaglist.c: tag support (aka metadata)
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
24 * @short_description: List of tags and values used to describe media metadata
26 * List of tags and values used to describe media metadata.
28 * Strings in structures must be ASCII or UTF-8 encoded. Other encodings are
29 * not allowed. Strings must not be empty or %NULL.
36 #include "gst_private.h"
37 #include "math-compat.h"
38 #include "gst-i18n-lib.h"
39 #include "gsttaglist.h"
42 #include "gstbuffer.h"
44 #include "gststructure.h"
46 #include <gobject/gvaluecollector.h>
49 /* FIXME: add category for tags */
50 #define GST_CAT_TAGS GST_CAT_DEFAULT
52 #define GST_TAG_IS_VALID(tag) (gst_tag_get_info (tag) != NULL)
54 typedef struct _GstTagListImpl
58 GstStructure *structure;
62 #define GST_TAG_LIST_STRUCTURE(taglist) ((GstTagListImpl*)(taglist))->structure
63 #define GST_TAG_LIST_SCOPE(taglist) ((GstTagListImpl*)(taglist))->scope
67 GType type; /* type the data is in */
69 const gchar *nick; /* translated short description */
70 const gchar *blurb; /* translated long description */
72 GstTagMergeFunc merge_func; /* functions to merge the values */
73 GstTagFlag flag; /* type of tag */
74 GQuark name_quark; /* quark for the name */
78 #define g_value_get_char g_value_get_schar
80 static GMutex __tag_mutex;
81 #define TAG_LOCK g_mutex_lock (&__tag_mutex)
82 #define TAG_UNLOCK g_mutex_unlock (&__tag_mutex)
84 /* tags hash table: maps tag name string => GstTagInfo */
85 static GHashTable *__tags;
87 GType _gst_tag_list_type = 0;
88 GST_DEFINE_MINI_OBJECT_TYPE (GstTagList, gst_tag_list);
90 static void __gst_tag_list_free (GstTagList * list);
91 static GstTagList *__gst_tag_list_copy (const GstTagList * list);
94 * g_value_register_transform_func (_gst_tag_list_type, G_TYPE_STRING,
95 * _gst_structure_transform_to_string);
98 _priv_gst_tag_initialize (void)
100 g_mutex_init (&__tag_mutex);
102 _gst_tag_list_type = gst_tag_list_get_type ();
104 __tags = g_hash_table_new (g_str_hash, g_str_equal);
105 gst_tag_register_static (GST_TAG_TITLE, GST_TAG_FLAG_META,
107 _("title"), _("commonly used title"), gst_tag_merge_strings_with_comma);
108 gst_tag_register_static (GST_TAG_TITLE_SORTNAME, GST_TAG_FLAG_META,
110 _("title sortname"), _("commonly used title for sorting purposes"), NULL);
111 gst_tag_register_static (GST_TAG_ARTIST, GST_TAG_FLAG_META,
114 _("person(s) responsible for the recording"),
115 gst_tag_merge_strings_with_comma);
116 gst_tag_register_static (GST_TAG_ARTIST_SORTNAME, GST_TAG_FLAG_META,
118 _("artist sortname"),
119 _("person(s) responsible for the recording for sorting purposes"), NULL);
120 gst_tag_register_static (GST_TAG_ALBUM, GST_TAG_FLAG_META,
123 _("album containing this data"), gst_tag_merge_strings_with_comma);
124 gst_tag_register_static (GST_TAG_ALBUM_SORTNAME, GST_TAG_FLAG_META,
127 _("album containing this data for sorting purposes"), NULL);
128 gst_tag_register_static (GST_TAG_ALBUM_ARTIST, GST_TAG_FLAG_META,
131 _("The artist of the entire album, as it should be displayed"),
132 gst_tag_merge_strings_with_comma);
133 gst_tag_register_static (GST_TAG_ALBUM_ARTIST_SORTNAME, GST_TAG_FLAG_META,
135 _("album artist sortname"),
136 _("The artist of the entire album, as it should be sorted"), NULL);
137 gst_tag_register_static (GST_TAG_DATE, GST_TAG_FLAG_META, G_TYPE_DATE,
138 _("date"), _("date the data was created (as a GDate structure)"), NULL);
139 gst_tag_register_static (GST_TAG_DATE_TIME, GST_TAG_FLAG_META,
140 GST_TYPE_DATE_TIME, _("datetime"),
141 _("date and time the data was created (as a GstDateTime structure)"),
143 gst_tag_register_static (GST_TAG_GENRE, GST_TAG_FLAG_META,
146 _("genre this data belongs to"), gst_tag_merge_strings_with_comma);
147 gst_tag_register_static (GST_TAG_COMMENT, GST_TAG_FLAG_META,
150 _("free text commenting the data"), gst_tag_merge_use_first);
151 gst_tag_register_static (GST_TAG_EXTENDED_COMMENT, GST_TAG_FLAG_META,
153 _("extended comment"),
154 _("free text commenting the data in key=value or key[en]=comment form"),
155 gst_tag_merge_use_first);
156 gst_tag_register_static (GST_TAG_TRACK_NUMBER, GST_TAG_FLAG_META,
159 _("track number inside a collection"), gst_tag_merge_use_first);
160 gst_tag_register_static (GST_TAG_TRACK_COUNT, GST_TAG_FLAG_META,
163 _("count of tracks inside collection this track belongs to"),
164 gst_tag_merge_use_first);
165 gst_tag_register_static (GST_TAG_ALBUM_VOLUME_NUMBER, GST_TAG_FLAG_META,
168 _("disc number inside a collection"), gst_tag_merge_use_first);
169 gst_tag_register_static (GST_TAG_ALBUM_VOLUME_COUNT, GST_TAG_FLAG_META,
172 _("count of discs inside collection this disc belongs to"),
173 gst_tag_merge_use_first);
174 gst_tag_register_static (GST_TAG_LOCATION, GST_TAG_FLAG_META,
176 _("location"), _("Origin of media as a URI (location, where the "
177 "original of the file or stream is hosted)"),
178 gst_tag_merge_strings_with_comma);
179 gst_tag_register_static (GST_TAG_HOMEPAGE, GST_TAG_FLAG_META,
182 _("Homepage for this media (i.e. artist or movie homepage)"),
183 gst_tag_merge_strings_with_comma);
184 gst_tag_register_static (GST_TAG_DESCRIPTION, GST_TAG_FLAG_META,
185 G_TYPE_STRING, _("description"),
186 _("short text describing the content of the data"),
187 gst_tag_merge_strings_with_comma);
188 gst_tag_register_static (GST_TAG_VERSION, GST_TAG_FLAG_META, G_TYPE_STRING,
189 _("version"), _("version of this data"), NULL);
190 gst_tag_register_static (GST_TAG_ISRC, GST_TAG_FLAG_META, G_TYPE_STRING,
193 ("International Standard Recording Code - see http://www.ifpi.org/isrc/"),
195 /* FIXME: organization (fix what? tpm) */
196 gst_tag_register_static (GST_TAG_ORGANIZATION, GST_TAG_FLAG_META,
197 G_TYPE_STRING, _("organization"), _("organization"),
198 gst_tag_merge_strings_with_comma);
199 gst_tag_register_static (GST_TAG_COPYRIGHT, GST_TAG_FLAG_META,
200 G_TYPE_STRING, _("copyright"), _("copyright notice of the data"), NULL);
201 gst_tag_register_static (GST_TAG_COPYRIGHT_URI, GST_TAG_FLAG_META,
202 G_TYPE_STRING, _("copyright uri"),
203 _("URI to the copyright notice of the data"), NULL);
204 gst_tag_register_static (GST_TAG_ENCODED_BY, GST_TAG_FLAG_META, G_TYPE_STRING,
205 _("encoded by"), _("name of the encoding person or organization"),
206 gst_tag_merge_strings_with_comma);
207 gst_tag_register_static (GST_TAG_CONTACT, GST_TAG_FLAG_META,
209 _("contact"), _("contact information"), gst_tag_merge_strings_with_comma);
210 gst_tag_register_static (GST_TAG_LICENSE, GST_TAG_FLAG_META,
211 G_TYPE_STRING, _("license"), _("license of data"), NULL);
212 gst_tag_register_static (GST_TAG_LICENSE_URI, GST_TAG_FLAG_META,
213 G_TYPE_STRING, _("license uri"),
214 _("URI to the license of the data"), NULL);
215 gst_tag_register_static (GST_TAG_PERFORMER, GST_TAG_FLAG_META,
218 _("person(s) performing"), gst_tag_merge_strings_with_comma);
219 gst_tag_register_static (GST_TAG_COMPOSER, GST_TAG_FLAG_META,
222 _("person(s) who composed the recording"),
223 gst_tag_merge_strings_with_comma);
224 gst_tag_register_static (GST_TAG_DURATION, GST_TAG_FLAG_DECODED,
226 _("duration"), _("length in GStreamer time units (nanoseconds)"), NULL);
227 gst_tag_register_static (GST_TAG_CODEC, GST_TAG_FLAG_ENCODED,
230 _("codec the data is stored in"), gst_tag_merge_strings_with_comma);
231 gst_tag_register_static (GST_TAG_VIDEO_CODEC, GST_TAG_FLAG_ENCODED,
233 _("video codec"), _("codec the video data is stored in"), NULL);
234 gst_tag_register_static (GST_TAG_AUDIO_CODEC, GST_TAG_FLAG_ENCODED,
236 _("audio codec"), _("codec the audio data is stored in"), NULL);
237 gst_tag_register_static (GST_TAG_SUBTITLE_CODEC, GST_TAG_FLAG_ENCODED,
239 _("subtitle codec"), _("codec the subtitle data is stored in"), NULL);
240 gst_tag_register_static (GST_TAG_CONTAINER_FORMAT, GST_TAG_FLAG_ENCODED,
241 G_TYPE_STRING, _("container format"),
242 _("container format the data is stored in"), NULL);
243 gst_tag_register_static (GST_TAG_BITRATE, GST_TAG_FLAG_ENCODED,
244 G_TYPE_UINT, _("bitrate"), _("exact or average bitrate in bits/s"), NULL);
245 gst_tag_register_static (GST_TAG_NOMINAL_BITRATE, GST_TAG_FLAG_ENCODED,
246 G_TYPE_UINT, _("nominal bitrate"), _("nominal bitrate in bits/s"), NULL);
247 gst_tag_register_static (GST_TAG_MINIMUM_BITRATE, GST_TAG_FLAG_ENCODED,
248 G_TYPE_UINT, _("minimum bitrate"), _("minimum bitrate in bits/s"), NULL);
249 gst_tag_register_static (GST_TAG_MAXIMUM_BITRATE, GST_TAG_FLAG_ENCODED,
250 G_TYPE_UINT, _("maximum bitrate"), _("maximum bitrate in bits/s"), NULL);
251 gst_tag_register_static (GST_TAG_ENCODER, GST_TAG_FLAG_ENCODED,
253 _("encoder"), _("encoder used to encode this stream"), NULL);
254 gst_tag_register_static (GST_TAG_ENCODER_VERSION, GST_TAG_FLAG_ENCODED,
256 _("encoder version"),
257 _("version of the encoder used to encode this stream"), NULL);
258 gst_tag_register_static (GST_TAG_SERIAL, GST_TAG_FLAG_ENCODED,
259 G_TYPE_UINT, _("serial"), _("serial number of track"), NULL);
260 gst_tag_register_static (GST_TAG_TRACK_GAIN, GST_TAG_FLAG_META,
261 G_TYPE_DOUBLE, _("replaygain track gain"), _("track gain in db"), NULL);
262 gst_tag_register_static (GST_TAG_TRACK_PEAK, GST_TAG_FLAG_META,
263 G_TYPE_DOUBLE, _("replaygain track peak"), _("peak of the track"), NULL);
264 gst_tag_register_static (GST_TAG_ALBUM_GAIN, GST_TAG_FLAG_META,
265 G_TYPE_DOUBLE, _("replaygain album gain"), _("album gain in db"), NULL);
266 gst_tag_register_static (GST_TAG_ALBUM_PEAK, GST_TAG_FLAG_META,
267 G_TYPE_DOUBLE, _("replaygain album peak"), _("peak of the album"), NULL);
268 gst_tag_register_static (GST_TAG_REFERENCE_LEVEL, GST_TAG_FLAG_META,
269 G_TYPE_DOUBLE, _("replaygain reference level"),
270 _("reference level of track and album gain values"), NULL);
271 gst_tag_register_static (GST_TAG_LANGUAGE_CODE, GST_TAG_FLAG_META,
272 G_TYPE_STRING, _("language code"),
273 _("language code for this stream, conforming to ISO-639-1 or ISO-639-2"),
275 gst_tag_register_static (GST_TAG_LANGUAGE_NAME, GST_TAG_FLAG_META,
276 G_TYPE_STRING, _("language name"),
277 _("freeform name of the language this stream is in"), NULL);
278 gst_tag_register_static (GST_TAG_IMAGE, GST_TAG_FLAG_META, GST_TYPE_SAMPLE,
279 _("image"), _("image related to this stream"), gst_tag_merge_use_first);
281 gst_tag_register_static (GST_TAG_AUDIO_DUALMONO, GST_TAG_FLAG_DECODED, G_TYPE_UINT,
282 _("dualmono audio"), _("dual/mono related to this audio stream"), NULL);
284 gst_tag_register_static (GST_TAG_PREVIEW_IMAGE, GST_TAG_FLAG_META,
286 /* TRANSLATORS: 'preview image' = image that shows a preview of the full image */
287 _("preview image"), _("preview image related to this stream"), NULL);
288 gst_tag_register_static (GST_TAG_ATTACHMENT, GST_TAG_FLAG_META,
289 GST_TYPE_SAMPLE, _("attachment"), _("file attached to this stream"),
290 gst_tag_merge_use_first);
291 gst_tag_register_static (GST_TAG_BEATS_PER_MINUTE, GST_TAG_FLAG_META,
292 G_TYPE_DOUBLE, _("beats per minute"),
293 _("number of beats per minute in audio"), NULL);
294 gst_tag_register_static (GST_TAG_KEYWORDS, GST_TAG_FLAG_META, G_TYPE_STRING,
295 _("keywords"), _("comma separated keywords describing the content"),
296 gst_tag_merge_strings_with_comma);
297 gst_tag_register_static (GST_TAG_GEO_LOCATION_NAME, GST_TAG_FLAG_META,
298 G_TYPE_STRING, _("geo location name"),
299 _("human readable descriptive location of where "
300 "the media has been recorded or produced"), NULL);
301 gst_tag_register_static (GST_TAG_GEO_LOCATION_LATITUDE, GST_TAG_FLAG_META,
302 G_TYPE_DOUBLE, _("geo location latitude"),
303 _("geo latitude location of where the media has been recorded or "
304 "produced in degrees according to WGS84 (zero at the equator, "
305 "negative values for southern latitudes)"), NULL);
306 gst_tag_register_static (GST_TAG_GEO_LOCATION_LONGITUDE, GST_TAG_FLAG_META,
307 G_TYPE_DOUBLE, _("geo location longitude"),
308 _("geo longitude location of where the media has been recorded or "
309 "produced in degrees according to WGS84 (zero at the prime meridian "
310 "in Greenwich/UK, negative values for western longitudes)"), NULL);
311 gst_tag_register_static (GST_TAG_GEO_LOCATION_ELEVATION, GST_TAG_FLAG_META,
312 G_TYPE_DOUBLE, _("geo location elevation"),
313 _("geo elevation of where the media has been recorded or produced in "
314 "meters according to WGS84 (zero is average sea level)"), NULL);
315 gst_tag_register_static (GST_TAG_GEO_LOCATION_COUNTRY, GST_TAG_FLAG_META,
316 G_TYPE_STRING, _("geo location country"),
317 _("country (english name) where the media has been recorded "
318 "or produced"), NULL);
319 gst_tag_register_static (GST_TAG_GEO_LOCATION_CITY, GST_TAG_FLAG_META,
320 G_TYPE_STRING, _("geo location city"),
321 _("city (english name) where the media has been recorded "
322 "or produced"), NULL);
323 gst_tag_register_static (GST_TAG_GEO_LOCATION_SUBLOCATION, GST_TAG_FLAG_META,
324 G_TYPE_STRING, _("geo location sublocation"),
325 _("a location within a city where the media has been produced "
326 "or created (e.g. the neighborhood)"), NULL);
327 gst_tag_register_static (GST_TAG_GEO_LOCATION_HORIZONTAL_ERROR,
328 GST_TAG_FLAG_META, G_TYPE_DOUBLE, _("geo location horizontal error"),
329 _("expected error of the horizontal positioning measures (in meters)"),
331 gst_tag_register_static (GST_TAG_GEO_LOCATION_MOVEMENT_SPEED,
332 GST_TAG_FLAG_META, G_TYPE_DOUBLE, _("geo location movement speed"),
333 _("movement speed of the capturing device while performing the capture "
335 gst_tag_register_static (GST_TAG_GEO_LOCATION_MOVEMENT_DIRECTION,
336 GST_TAG_FLAG_META, G_TYPE_DOUBLE, _("geo location movement direction"),
337 _("indicates the movement direction of the device performing the capture"
338 " of a media. It is represented as degrees in floating point "
339 "representation, 0 means the geographic north, and increases "
341 gst_tag_register_static (GST_TAG_GEO_LOCATION_CAPTURE_DIRECTION,
342 GST_TAG_FLAG_META, G_TYPE_DOUBLE, _("geo location capture direction"),
343 _("indicates the direction the device is pointing to when capturing "
344 " a media. It is represented as degrees in floating point "
345 " representation, 0 means the geographic north, and increases "
347 gst_tag_register_static (GST_TAG_SHOW_NAME, GST_TAG_FLAG_META, G_TYPE_STRING,
348 /* TRANSLATORS: 'show name' = 'TV/radio/podcast show name' here */
350 _("Name of the tv/podcast/series show the media is from"),
351 gst_tag_merge_strings_with_comma);
352 gst_tag_register_static (GST_TAG_SHOW_SORTNAME, GST_TAG_FLAG_META,
354 /* TRANSLATORS: 'show sortname' = 'TV/radio/podcast show name as used for sorting purposes' here */
356 _("Name of the tv/podcast/series show the media is from, for sorting "
358 gst_tag_register_static (GST_TAG_SHOW_EPISODE_NUMBER, GST_TAG_FLAG_META,
359 G_TYPE_UINT, _("episode number"),
360 _("The episode number in the season the media is part of"),
361 gst_tag_merge_use_first);
362 gst_tag_register_static (GST_TAG_SHOW_SEASON_NUMBER, GST_TAG_FLAG_META,
363 G_TYPE_UINT, _("season number"),
364 _("The season number of the show the media is part of"),
365 gst_tag_merge_use_first);
366 gst_tag_register_static (GST_TAG_LYRICS, GST_TAG_FLAG_META, G_TYPE_STRING,
367 _("lyrics"), _("The lyrics of the media, commonly used for songs"),
368 gst_tag_merge_strings_with_comma);
369 gst_tag_register_static (GST_TAG_COMPOSER_SORTNAME, GST_TAG_FLAG_META,
370 G_TYPE_STRING, _("composer sortname"),
371 _("person(s) who composed the recording, for sorting purposes"), NULL);
372 gst_tag_register_static (GST_TAG_GROUPING, GST_TAG_FLAG_META, G_TYPE_STRING,
374 _("Groups related media that spans multiple tracks, like the different "
375 "pieces of a concerto. It is a higher level than a track, "
376 "but lower than an album"), NULL);
377 gst_tag_register_static (GST_TAG_USER_RATING, GST_TAG_FLAG_META, G_TYPE_UINT,
379 _("Rating attributed by a user. The higher the rank, "
380 "the more the user likes this media"), NULL);
381 gst_tag_register_static (GST_TAG_DEVICE_MANUFACTURER, GST_TAG_FLAG_META,
382 G_TYPE_STRING, _("device manufacturer"),
383 _("Manufacturer of the device used to create this media"), NULL);
384 gst_tag_register_static (GST_TAG_DEVICE_MODEL, GST_TAG_FLAG_META,
385 G_TYPE_STRING, _("device model"),
386 _("Model of the device used to create this media"), NULL);
387 gst_tag_register_static (GST_TAG_APPLICATION_NAME, GST_TAG_FLAG_META,
388 G_TYPE_STRING, _("application name"),
389 _("Application used to create the media"), NULL);
390 gst_tag_register_static (GST_TAG_APPLICATION_DATA, GST_TAG_FLAG_META,
391 GST_TYPE_SAMPLE, _("application data"),
392 _("Arbitrary application data to be serialized into the media"), NULL);
393 gst_tag_register_static (GST_TAG_IMAGE_ORIENTATION, GST_TAG_FLAG_META,
394 G_TYPE_STRING, _("image orientation"),
395 _("How the image should be rotated or flipped before display"), NULL);
396 gst_tag_register_static (GST_TAG_PUBLISHER, GST_TAG_FLAG_META,
399 _("Name of the label or publisher"), gst_tag_merge_strings_with_comma);
400 gst_tag_register_static (GST_TAG_INTERPRETED_BY, GST_TAG_FLAG_META,
403 _("Information about the people behind a remix and similar "
404 "interpretations"), gst_tag_merge_strings_with_comma);
405 gst_tag_register_static (GST_TAG_MIDI_BASE_NOTE, GST_TAG_FLAG_META,
407 _("midi-base-note"), _("Midi note number of the audio track."), NULL);
411 * gst_tag_merge_use_first:
412 * @dest: (out caller-allocates): uninitialized GValue to store result in
413 * @src: GValue to copy from
415 * This is a convenience function for the func argument of gst_tag_register().
416 * It creates a copy of the first value from the list.
419 gst_tag_merge_use_first (GValue * dest, const GValue * src)
421 const GValue *ret = gst_value_list_get_value (src, 0);
423 g_value_init (dest, G_VALUE_TYPE (ret));
424 g_value_copy (ret, dest);
428 * gst_tag_merge_strings_with_comma:
429 * @dest: (out caller-allocates): uninitialized GValue to store result in
430 * @src: GValue to copy from
432 * This is a convenience function for the func argument of gst_tag_register().
433 * It concatenates all given strings using a comma. The tag must be registered
434 * as a G_TYPE_STRING or this function will fail.
437 gst_tag_merge_strings_with_comma (GValue * dest, const GValue * src)
442 count = gst_value_list_get_size (src);
443 str = g_string_new (g_value_get_string (gst_value_list_get_value (src, 0)));
444 for (i = 1; i < count; i++) {
445 /* separator between two strings */
446 g_string_append (str, _(", "));
447 g_string_append (str,
448 g_value_get_string (gst_value_list_get_value (src, i)));
451 g_value_init (dest, G_TYPE_STRING);
452 g_value_take_string (dest, str->str);
453 g_string_free (str, FALSE);
457 gst_tag_lookup (const gchar * tag_name)
462 ret = g_hash_table_lookup (__tags, (gpointer) tag_name);
470 * @name: the name or identifier string
471 * @flag: a flag describing the type of tag info
472 * @type: the type this data is in
473 * @nick: human-readable name
474 * @blurb: a human-readable description about this tag
475 * @func: (allow-none) (scope call): function for merging multiple values of this tag, or %NULL
477 * Registers a new tag type for the use with GStreamer's type system. If a type
478 * with that name is already registered, that one is used.
479 * The old registration may have used a different type however. So don't rely
480 * on your supplied values.
482 * Important: if you do not supply a merge function the implication will be
483 * that there can only be one single value for this tag in a tag list and
484 * any additional values will silently be discarded when being added (unless
485 * #GST_TAG_MERGE_REPLACE, #GST_TAG_MERGE_REPLACE_ALL, or
486 * #GST_TAG_MERGE_PREPEND is used as merge mode, in which case the new
487 * value will replace the old one in the list).
489 * The merge function will be called from gst_tag_list_copy_value() when
490 * it is required that one or more values for a tag be condensed into
491 * one single value. This may happen from gst_tag_list_get_string(),
492 * gst_tag_list_get_int(), gst_tag_list_get_double() etc. What will happen
493 * exactly in that case depends on how the tag was registered and if a
494 * merge function was supplied and if so which one.
496 * Two default merge functions are provided: gst_tag_merge_use_first() and
497 * gst_tag_merge_strings_with_comma().
500 gst_tag_register (const gchar * name, GstTagFlag flag, GType type,
501 const gchar * nick, const gchar * blurb, GstTagMergeFunc func)
503 g_return_if_fail (name != NULL);
504 g_return_if_fail (nick != NULL);
505 g_return_if_fail (blurb != NULL);
506 g_return_if_fail (type != 0 && type != GST_TYPE_LIST);
508 return gst_tag_register_static (g_intern_string (name), flag, type,
509 g_intern_string (nick), g_intern_string (blurb), func);
513 * gst_tag_register_static:
514 * @name: the name or identifier string (string constant)
515 * @flag: a flag describing the type of tag info
516 * @type: the type this data is in
517 * @nick: human-readable name or short description (string constant)
518 * @blurb: a human-readable description for this tag (string constant)
519 * @func: (allow-none) (scope call): function for merging multiple values of this tag, or %NULL
521 * Registers a new tag type for the use with GStreamer's type system.
523 * Same as gst_tag_register(), but @name, @nick, and @blurb must be
524 * static strings or inlined strings, as they will not be copied. (GStreamer
525 * plugins will be made resident once loaded, so this function can be used
526 * even from dynamically loaded plugins.)
529 gst_tag_register_static (const gchar * name, GstTagFlag flag, GType type,
530 const gchar * nick, const gchar * blurb, GstTagMergeFunc func)
534 g_return_if_fail (name != NULL);
535 g_return_if_fail (nick != NULL);
536 g_return_if_fail (blurb != NULL);
537 g_return_if_fail (type != 0 && type != GST_TYPE_LIST);
539 info = gst_tag_lookup (name);
542 g_return_if_fail (info->type == type);
546 info = g_slice_new (GstTagInfo);
549 info->name_quark = g_quark_from_static_string (name);
552 info->merge_func = func;
555 g_hash_table_insert (__tags, (gpointer) name, info);
561 * @tag: name of the tag
563 * Checks if the given type is already registered.
565 * Returns: %TRUE if the type is already registered
568 gst_tag_exists (const gchar * tag)
570 g_return_val_if_fail (tag != NULL, FALSE);
572 return gst_tag_lookup (tag) != NULL;
579 * Gets the #GType used for this tag.
581 * Returns: the #GType of this tag
584 gst_tag_get_type (const gchar * tag)
588 g_return_val_if_fail (tag != NULL, 0);
589 info = gst_tag_lookup (tag);
590 g_return_val_if_fail (info != NULL, 0);
599 * Returns the human-readable name of this tag, You must not change or free
602 * Returns: the human-readable name of this tag
605 gst_tag_get_nick (const gchar * tag)
609 g_return_val_if_fail (tag != NULL, NULL);
610 info = gst_tag_lookup (tag);
611 g_return_val_if_fail (info != NULL, NULL);
617 * gst_tag_get_description:
620 * Returns the human-readable description of this tag, You must not change or
623 * Returns: the human-readable description of this tag
626 gst_tag_get_description (const gchar * tag)
630 g_return_val_if_fail (tag != NULL, NULL);
631 info = gst_tag_lookup (tag);
632 g_return_val_if_fail (info != NULL, NULL);
641 * Gets the flag of @tag.
643 * Returns: the flag of this tag.
646 gst_tag_get_flag (const gchar * tag)
650 g_return_val_if_fail (tag != NULL, GST_TAG_FLAG_UNDEFINED);
651 info = gst_tag_lookup (tag);
652 g_return_val_if_fail (info != NULL, GST_TAG_FLAG_UNDEFINED);
661 * Checks if the given tag is fixed. A fixed tag can only contain one value.
662 * Unfixed tags can contain lists of values.
664 * Returns: %TRUE, if the given tag is fixed.
667 gst_tag_is_fixed (const gchar * tag)
671 g_return_val_if_fail (tag != NULL, FALSE);
672 info = gst_tag_lookup (tag);
673 g_return_val_if_fail (info != NULL, FALSE);
675 return info->merge_func == NULL;
678 /* takes ownership of the structure */
680 gst_tag_list_new_internal (GstStructure * s, GstTagScope scope)
682 GstTagList *tag_list;
684 g_assert (s != NULL);
686 tag_list = (GstTagList *) g_slice_new (GstTagListImpl);
688 gst_mini_object_init (GST_MINI_OBJECT_CAST (tag_list), 0, GST_TYPE_TAG_LIST,
689 (GstMiniObjectCopyFunction) __gst_tag_list_copy, NULL,
690 (GstMiniObjectFreeFunction) __gst_tag_list_free);
692 GST_TAG_LIST_STRUCTURE (tag_list) = s;
693 GST_TAG_LIST_SCOPE (tag_list) = scope;
695 #ifdef DEBUG_REFCOUNT
696 GST_CAT_TRACE (GST_CAT_TAGS, "created taglist %p", tag_list);
703 __gst_tag_list_free (GstTagList * list)
705 g_return_if_fail (GST_IS_TAG_LIST (list));
707 #ifdef DEBUG_REFCOUNT
708 GST_CAT_TRACE (GST_CAT_TAGS, "freeing taglist %p", list);
711 gst_structure_free (GST_TAG_LIST_STRUCTURE (list));
713 g_slice_free1 (sizeof (GstTagListImpl), list);
717 __gst_tag_list_copy (const GstTagList * list)
719 const GstStructure *s;
721 g_return_val_if_fail (GST_IS_TAG_LIST (list), NULL);
723 s = GST_TAG_LIST_STRUCTURE (list);
724 return gst_tag_list_new_internal (gst_structure_copy (s),
725 GST_TAG_LIST_SCOPE (list));
729 * gst_tag_list_new_empty:
731 * Creates a new empty GstTagList.
733 * Free-function: gst_tag_list_unref
735 * Returns: (transfer full): An empty tag list
738 gst_tag_list_new_empty (void)
741 GstTagList *tag_list;
743 s = gst_structure_new_id_empty (GST_QUARK (TAGLIST));
744 tag_list = gst_tag_list_new_internal (s, GST_TAG_SCOPE_STREAM);
751 * @...: %NULL-terminated list of values to set
753 * Creates a new taglist and appends the values for the given tags. It expects
754 * tag-value pairs like gst_tag_list_add(), and a %NULL terminator after the
755 * last pair. The type of the values is implicit and is documented in the API
756 * reference, but can also be queried at runtime with gst_tag_get_type(). It
757 * is an error to pass a value of a type not matching the tag type into this
758 * function. The tag list will make copies of any arguments passed
759 * (e.g. strings, buffers).
761 * After creation you might also want to set a #GstTagScope on the returned
762 * taglist to signal if the contained tags are global or stream tags. By
763 * default stream scope is assumes. See gst_tag_list_set_scope().
765 * Free-function: gst_tag_list_unref
767 * Returns: (transfer full): a new #GstTagList. Free with gst_tag_list_unref()
768 * when no longer needed.
771 gst_tag_list_new (const gchar * tag, ...)
776 g_return_val_if_fail (tag != NULL, NULL);
778 list = gst_tag_list_new_empty ();
779 va_start (args, tag);
780 gst_tag_list_add_valist (list, GST_TAG_MERGE_APPEND, tag, args);
787 * gst_tag_list_new_valist:
788 * @var_args: tag / value pairs to set
790 * Just like gst_tag_list_new(), only that it takes a va_list argument.
791 * Useful mostly for language bindings.
793 * Free-function: gst_tag_list_unref
795 * Returns: (transfer full): a new #GstTagList. Free with gst_tag_list_unref()
796 * when no longer needed.
799 gst_tag_list_new_valist (va_list var_args)
804 list = gst_tag_list_new_empty ();
806 tag = va_arg (var_args, gchar *);
807 gst_tag_list_add_valist (list, GST_TAG_MERGE_APPEND, tag, var_args);
813 * gst_tag_list_set_scope:
814 * @list: a #GstTagList
815 * @scope: new scope for @list
817 * Sets the scope of @list to @scope. By default the scope
818 * of a taglist is stream scope.
822 gst_tag_list_set_scope (GstTagList * list, GstTagScope scope)
824 g_return_if_fail (GST_IS_TAG_LIST (list));
825 g_return_if_fail (gst_tag_list_is_writable (list));
827 GST_TAG_LIST_SCOPE (list) = scope;
831 * gst_tag_list_get_scope:
832 * @list: a #GstTagList
834 * Gets the scope of @list.
836 * Returns: The scope of @list
839 gst_tag_list_get_scope (const GstTagList * list)
841 g_return_val_if_fail (GST_IS_TAG_LIST (list), GST_TAG_SCOPE_STREAM);
843 return GST_TAG_LIST_SCOPE (list);
847 * gst_tag_list_to_string:
848 * @list: a #GstTagList
850 * Serializes a tag list to a string.
852 * Returns: (nullable): a newly-allocated string, or %NULL in case of
853 * an error. The string must be freed with g_free() when no longer
857 gst_tag_list_to_string (const GstTagList * list)
859 g_return_val_if_fail (GST_IS_TAG_LIST (list), NULL);
861 return gst_structure_to_string (GST_TAG_LIST_STRUCTURE (list));
865 * gst_tag_list_new_from_string:
866 * @str: a string created with gst_tag_list_to_string()
868 * Deserializes a tag list.
870 * Returns: (nullable): a new #GstTagList, or %NULL in case of an
874 gst_tag_list_new_from_string (const gchar * str)
876 GstTagList *tag_list;
879 g_return_val_if_fail (str != NULL, NULL);
880 g_return_val_if_fail (g_str_has_prefix (str, "taglist"), NULL);
882 s = gst_structure_from_string (str, NULL);
886 tag_list = gst_tag_list_new_internal (s, GST_TAG_SCOPE_STREAM);
892 * gst_tag_list_n_tags:
893 * @list: A #GstTagList.
895 * Get the number of tags in @list.
897 * Returns: The number of tags in @list.
900 gst_tag_list_n_tags (const GstTagList * list)
902 g_return_val_if_fail (list != NULL, 0);
903 g_return_val_if_fail (GST_IS_TAG_LIST (list), 0);
905 return gst_structure_n_fields (GST_TAG_LIST_STRUCTURE (list));
909 * gst_tag_list_nth_tag_name:
910 * @list: A #GstTagList.
913 * Get the name of the tag in @list at @index.
915 * Returns: The name of the tag at @index.
918 gst_tag_list_nth_tag_name (const GstTagList * list, guint index)
920 g_return_val_if_fail (list != NULL, 0);
921 g_return_val_if_fail (GST_IS_TAG_LIST (list), 0);
923 return gst_structure_nth_field_name (GST_TAG_LIST_STRUCTURE (list), index);
927 * gst_tag_list_is_empty:
928 * @list: A #GstTagList.
930 * Checks if the given taglist is empty.
932 * Returns: %TRUE if the taglist is empty, otherwise %FALSE.
935 gst_tag_list_is_empty (const GstTagList * list)
937 g_return_val_if_fail (list != NULL, FALSE);
938 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
940 return (gst_structure_n_fields (GST_TAG_LIST_STRUCTURE (list)) == 0);
944 gst_tag_list_fields_equal (const GValue * value1, const GValue * value2)
948 if (gst_value_compare (value1, value2) == GST_VALUE_EQUAL)
951 /* fields not equal: add some tolerance for doubles, otherwise bail out */
952 if (!G_VALUE_HOLDS_DOUBLE (value1) || !G_VALUE_HOLDS_DOUBLE (value2))
955 d1 = g_value_get_double (value1);
956 d2 = g_value_get_double (value2);
958 /* This will only work for 'normal' values and values around 0,
959 * which should be good enough for our purposes here
960 * FIXME: maybe add this to gst_value_compare_double() ? */
961 return (fabs (d1 - d2) < 0.0000001);
965 * gst_tag_list_is_equal:
966 * @list1: a #GstTagList.
967 * @list2: a #GstTagList.
969 * Checks if the two given taglists are equal.
971 * Returns: %TRUE if the taglists are equal, otherwise %FALSE
974 gst_tag_list_is_equal (const GstTagList * list1, const GstTagList * list2)
976 const GstStructure *s1, *s2;
977 gint num_fields1, num_fields2, i;
979 g_return_val_if_fail (GST_IS_TAG_LIST (list1), FALSE);
980 g_return_val_if_fail (GST_IS_TAG_LIST (list2), FALSE);
982 /* we don't just use gst_structure_is_equal() here so we can add some
983 * tolerance for doubles, though maybe we should just add that to
984 * gst_value_compare_double() as well? */
985 s1 = GST_TAG_LIST_STRUCTURE (list1);
986 s2 = GST_TAG_LIST_STRUCTURE (list2);
988 num_fields1 = gst_structure_n_fields (s1);
989 num_fields2 = gst_structure_n_fields (s2);
991 if (num_fields1 != num_fields2)
994 for (i = 0; i < num_fields1; i++) {
995 const GValue *value1, *value2;
996 const gchar *tag_name;
998 tag_name = gst_structure_nth_field_name (s1, i);
999 value1 = gst_structure_get_value (s1, tag_name);
1000 value2 = gst_structure_get_value (s2, tag_name);
1005 if (!gst_tag_list_fields_equal (value1, value2))
1015 GstTagMergeMode mode;
1020 gst_tag_list_add_value_internal (GstTagList * tag_list, GstTagMergeMode mode,
1021 const gchar * tag, const GValue * value, GstTagInfo * info)
1023 GstStructure *list = GST_TAG_LIST_STRUCTURE (tag_list);
1024 const GValue *value2;
1028 info = gst_tag_lookup (tag);
1029 if (G_UNLIKELY (info == NULL)) {
1030 g_warning ("unknown tag '%s'", tag);
1035 if (G_UNLIKELY (!G_VALUE_HOLDS (value, info->type) &&
1036 !GST_VALUE_HOLDS_LIST (value))) {
1037 g_warning ("tag '%s' should hold value of type '%s', but value of "
1038 "type '%s' passed", info->nick, g_type_name (info->type),
1039 g_type_name (G_VALUE_TYPE (value)));
1043 tag_quark = info->name_quark;
1045 if (info->merge_func
1046 && (value2 = gst_structure_id_get_value (list, tag_quark)) != NULL) {
1047 GValue dest = { 0, };
1050 case GST_TAG_MERGE_REPLACE_ALL:
1051 case GST_TAG_MERGE_REPLACE:
1052 gst_structure_id_set_value (list, tag_quark, value);
1054 case GST_TAG_MERGE_PREPEND:
1055 if (GST_VALUE_HOLDS_LIST (value2) && !GST_VALUE_HOLDS_LIST (value))
1056 gst_value_list_prepend_value ((GValue *) value2, value);
1058 gst_value_list_merge (&dest, value, value2);
1059 gst_structure_id_take_value (list, tag_quark, &dest);
1062 case GST_TAG_MERGE_APPEND:
1063 if (GST_VALUE_HOLDS_LIST (value2) && !GST_VALUE_HOLDS_LIST (value))
1064 gst_value_list_append_value ((GValue *) value2, value);
1066 gst_value_list_merge (&dest, value2, value);
1067 gst_structure_id_take_value (list, tag_quark, &dest);
1070 case GST_TAG_MERGE_KEEP:
1071 case GST_TAG_MERGE_KEEP_ALL:
1074 g_assert_not_reached ();
1079 case GST_TAG_MERGE_APPEND:
1080 case GST_TAG_MERGE_KEEP:
1081 if (gst_structure_id_get_value (list, tag_quark) != NULL)
1084 case GST_TAG_MERGE_REPLACE_ALL:
1085 case GST_TAG_MERGE_REPLACE:
1086 case GST_TAG_MERGE_PREPEND:
1087 gst_structure_id_set_value (list, tag_quark, value);
1089 case GST_TAG_MERGE_KEEP_ALL:
1092 g_assert_not_reached ();
1099 gst_tag_list_copy_foreach (GQuark tag_quark, const GValue * value,
1102 GstTagCopyData *copy = (GstTagCopyData *) user_data;
1105 tag = g_quark_to_string (tag_quark);
1106 gst_tag_list_add_value_internal (copy->list, copy->mode, tag, value, NULL);
1112 * gst_tag_list_insert:
1113 * @into: list to merge into
1114 * @from: list to merge from
1115 * @mode: the mode to use
1117 * Inserts the tags of the @from list into the first list using the given mode.
1120 gst_tag_list_insert (GstTagList * into, const GstTagList * from,
1121 GstTagMergeMode mode)
1123 GstTagCopyData data;
1125 g_return_if_fail (GST_IS_TAG_LIST (into));
1126 g_return_if_fail (gst_tag_list_is_writable (into));
1127 g_return_if_fail (GST_IS_TAG_LIST (from));
1128 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1132 if (mode == GST_TAG_MERGE_REPLACE_ALL) {
1133 gst_structure_remove_all_fields (GST_TAG_LIST_STRUCTURE (into));
1135 gst_structure_foreach (GST_TAG_LIST_STRUCTURE (from),
1136 gst_tag_list_copy_foreach, &data);
1140 * gst_tag_list_merge:
1141 * @list1: (allow-none): first list to merge
1142 * @list2: (allow-none): second list to merge
1143 * @mode: the mode to use
1145 * Merges the two given lists into a new list. If one of the lists is %NULL, a
1146 * copy of the other is returned. If both lists are %NULL, %NULL is returned.
1148 * Free-function: gst_tag_list_unref
1150 * Returns: (transfer full) (nullable): the new list
1153 gst_tag_list_merge (const GstTagList * list1, const GstTagList * list2,
1154 GstTagMergeMode mode)
1156 GstTagList *list1_cp;
1157 const GstTagList *list2_cp;
1159 g_return_val_if_fail (list1 == NULL || GST_IS_TAG_LIST (list1), NULL);
1160 g_return_val_if_fail (list2 == NULL || GST_IS_TAG_LIST (list2), NULL);
1161 g_return_val_if_fail (GST_TAG_MODE_IS_VALID (mode), NULL);
1163 /* nothing to merge */
1164 if (!list1 && !list2) {
1168 /* create empty list, we need to do this to correctly handling merge modes */
1169 list1_cp = (list1) ? gst_tag_list_copy (list1) : gst_tag_list_new_empty ();
1170 list2_cp = (list2) ? list2 : gst_tag_list_new_empty ();
1172 gst_tag_list_insert (list1_cp, list2_cp, mode);
1175 gst_tag_list_unref ((GstTagList *) list2_cp);
1181 * gst_tag_list_get_tag_size:
1183 * @tag: the tag to query
1185 * Checks how many value are stored in this tag list for the given tag.
1187 * Returns: The number of tags stored
1190 gst_tag_list_get_tag_size (const GstTagList * list, const gchar * tag)
1192 const GValue *value;
1194 g_return_val_if_fail (GST_IS_TAG_LIST (list), 0);
1196 value = gst_structure_get_value (GST_TAG_LIST_STRUCTURE (list), tag);
1199 if (G_VALUE_TYPE (value) != GST_TYPE_LIST)
1202 return gst_value_list_get_size (value);
1207 * @list: list to set tags in
1208 * @mode: the mode to use
1210 * @...: %NULL-terminated list of values to set
1212 * Sets the values for the given tags using the specified mode.
1215 gst_tag_list_add (GstTagList * list, GstTagMergeMode mode, const gchar * tag,
1220 g_return_if_fail (GST_IS_TAG_LIST (list));
1221 g_return_if_fail (gst_tag_list_is_writable (list));
1222 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1223 g_return_if_fail (tag != NULL);
1225 va_start (args, tag);
1226 gst_tag_list_add_valist (list, mode, tag, args);
1231 * gst_tag_list_add_values:
1232 * @list: list to set tags in
1233 * @mode: the mode to use
1235 * @...: GValues to set
1237 * Sets the GValues for the given tags using the specified mode.
1240 gst_tag_list_add_values (GstTagList * list, GstTagMergeMode mode,
1241 const gchar * tag, ...)
1245 g_return_if_fail (GST_IS_TAG_LIST (list));
1246 g_return_if_fail (gst_tag_list_is_writable (list));
1247 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1248 g_return_if_fail (tag != NULL);
1250 va_start (args, tag);
1251 gst_tag_list_add_valist_values (list, mode, tag, args);
1256 * gst_tag_list_add_valist:
1257 * @list: list to set tags in
1258 * @mode: the mode to use
1260 * @var_args: tag / value pairs to set
1262 * Sets the values for the given tags using the specified mode.
1265 gst_tag_list_add_valist (GstTagList * list, GstTagMergeMode mode,
1266 const gchar * tag, va_list var_args)
1269 gchar *error = NULL;
1271 g_return_if_fail (GST_IS_TAG_LIST (list));
1272 g_return_if_fail (gst_tag_list_is_writable (list));
1273 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1274 g_return_if_fail (tag != NULL);
1276 if (mode == GST_TAG_MERGE_REPLACE_ALL) {
1277 gst_structure_remove_all_fields (GST_TAG_LIST_STRUCTURE (list));
1280 while (tag != NULL) {
1281 GValue value = { 0, };
1283 info = gst_tag_lookup (tag);
1284 if (G_UNLIKELY (info == NULL)) {
1285 g_warning ("unknown tag '%s'", tag);
1288 G_VALUE_COLLECT_INIT (&value, info->type, var_args, 0, &error);
1290 g_warning ("%s: %s", G_STRLOC, error);
1292 /* we purposely leak the value here, it might not be
1293 * in a sane state if an error condition occoured
1297 /* Facilitate GstBuffer -> GstSample transition */
1298 if (G_UNLIKELY (info->type == GST_TYPE_SAMPLE &&
1299 !GST_IS_SAMPLE (value.data[0].v_pointer))) {
1300 g_warning ("Expected GstSample argument for tag '%s'", tag);
1302 gst_tag_list_add_value_internal (list, mode, tag, &value, info);
1304 g_value_unset (&value);
1305 tag = va_arg (var_args, gchar *);
1310 * gst_tag_list_add_valist_values:
1311 * @list: list to set tags in
1312 * @mode: the mode to use
1314 * @var_args: tag / GValue pairs to set
1316 * Sets the GValues for the given tags using the specified mode.
1319 gst_tag_list_add_valist_values (GstTagList * list, GstTagMergeMode mode,
1320 const gchar * tag, va_list var_args)
1322 g_return_if_fail (GST_IS_TAG_LIST (list));
1323 g_return_if_fail (gst_tag_list_is_writable (list));
1324 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1325 g_return_if_fail (tag != NULL);
1327 if (mode == GST_TAG_MERGE_REPLACE_ALL) {
1328 gst_structure_remove_all_fields (GST_TAG_LIST_STRUCTURE (list));
1331 while (tag != NULL) {
1334 info = gst_tag_lookup (tag);
1335 if (G_UNLIKELY (info == NULL)) {
1336 g_warning ("unknown tag '%s'", tag);
1339 gst_tag_list_add_value_internal (list, mode, tag, va_arg (var_args,
1341 tag = va_arg (var_args, gchar *);
1346 * gst_tag_list_add_value:
1347 * @list: list to set tags in
1348 * @mode: the mode to use
1350 * @value: GValue for this tag
1352 * Sets the GValue for a given tag using the specified mode.
1355 gst_tag_list_add_value (GstTagList * list, GstTagMergeMode mode,
1356 const gchar * tag, const GValue * value)
1358 g_return_if_fail (GST_IS_TAG_LIST (list));
1359 g_return_if_fail (gst_tag_list_is_writable (list));
1360 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1361 g_return_if_fail (tag != NULL);
1363 gst_tag_list_add_value_internal (list, mode, tag, value, NULL);
1367 * gst_tag_list_remove_tag:
1368 * @list: list to remove tag from
1369 * @tag: tag to remove
1371 * Removes the given tag from the taglist.
1374 gst_tag_list_remove_tag (GstTagList * list, const gchar * tag)
1376 g_return_if_fail (GST_IS_TAG_LIST (list));
1377 g_return_if_fail (tag != NULL);
1379 gst_structure_remove_field (GST_TAG_LIST_STRUCTURE (list), tag);
1384 GstTagForeachFunc func;
1385 const GstTagList *tag_list;
1391 structure_foreach_wrapper (GQuark field_id, const GValue * value,
1394 TagForeachData *data = (TagForeachData *) user_data;
1396 data->func (data->tag_list, g_quark_to_string (field_id), data->data);
1401 * gst_tag_list_foreach:
1402 * @list: list to iterate over
1403 * @func: (scope call): function to be called for each tag
1404 * @user_data: (closure): user specified data
1406 * Calls the given function for each tag inside the tag list. Note that if there
1407 * is no tag, the function won't be called at all.
1410 gst_tag_list_foreach (const GstTagList * list, GstTagForeachFunc func,
1413 TagForeachData data;
1415 g_return_if_fail (GST_IS_TAG_LIST (list));
1416 g_return_if_fail (func != NULL);
1419 data.tag_list = list;
1420 data.data = user_data;
1421 gst_structure_foreach (GST_TAG_LIST_STRUCTURE (list),
1422 structure_foreach_wrapper, &data);
1426 * gst_tag_list_get_value_index:
1427 * @list: a #GstTagList
1428 * @tag: tag to read out
1429 * @index: number of entry to read out
1431 * Gets the value that is at the given index for the given tag in the given
1434 * Returns: (transfer none) (nullable): The GValue for the specified
1435 * entry or %NULL if the tag wasn't available or the tag
1436 * doesn't have as many entries
1439 gst_tag_list_get_value_index (const GstTagList * list, const gchar * tag,
1442 const GValue *value;
1444 g_return_val_if_fail (GST_IS_TAG_LIST (list), NULL);
1445 g_return_val_if_fail (tag != NULL, NULL);
1447 value = gst_structure_get_value (GST_TAG_LIST_STRUCTURE (list), tag);
1451 if (GST_VALUE_HOLDS_LIST (value)) {
1452 if (index >= gst_value_list_get_size (value))
1454 return gst_value_list_get_value (value, index);
1463 * gst_tag_list_copy_value:
1464 * @dest: (out caller-allocates): uninitialized #GValue to copy into
1465 * @list: list to get the tag from
1466 * @tag: tag to read out
1468 * Copies the contents for the given tag into the value,
1469 * merging multiple values into one if multiple values are associated
1471 * You must g_value_unset() the value after use.
1473 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1477 gst_tag_list_copy_value (GValue * dest, const GstTagList * list,
1482 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1483 g_return_val_if_fail (tag != NULL, FALSE);
1484 g_return_val_if_fail (dest != NULL, FALSE);
1485 g_return_val_if_fail (G_VALUE_TYPE (dest) == 0, FALSE);
1487 src = gst_structure_get_value (GST_TAG_LIST_STRUCTURE (list), tag);
1491 if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
1492 GstTagInfo *info = gst_tag_lookup (tag);
1497 /* must be there or lists aren't allowed */
1498 g_assert (info->merge_func);
1499 info->merge_func (dest, src);
1501 g_value_init (dest, G_VALUE_TYPE (src));
1502 g_value_copy (src, dest);
1507 /* FIXME 2.0: this whole merge function business is overdesigned, and the
1508 * _get_foo() API is misleading as well - how many application developers will
1509 * expect gst_tag_list_get_string (list, GST_TAG_ARTIST, &val) might return a
1510 * string with multiple comma-separated artists? _get_foo() should just be
1511 * a convenience wrapper around _get_foo_index (list, tag, 0, &val),
1512 * supplemented by a special _tag_list_get_string_merged() function if needed
1513 * (unless someone can actually think of real use cases where the merge
1514 * function is not 'use first' for non-strings and merge for strings) */
1516 /***** evil macros to get all the gst_tag_list_get_*() functions right *****/
1518 #define TAG_MERGE_FUNCS(name,type,ret) \
1520 gst_tag_list_get_ ## name (const GstTagList *list, const gchar *tag, \
1523 GValue v = { 0, }; \
1525 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE); \
1526 g_return_val_if_fail (tag != NULL, FALSE); \
1527 g_return_val_if_fail (value != NULL, FALSE); \
1529 if (!gst_tag_list_copy_value (&v, list, tag)) \
1531 *value = COPY_FUNC (g_value_get_ ## name (&v)); \
1532 g_value_unset (&v); \
1537 gst_tag_list_get_ ## name ## _index (const GstTagList *list, \
1539 guint index, type *value) \
1543 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE); \
1544 g_return_val_if_fail (tag != NULL, FALSE); \
1545 g_return_val_if_fail (value != NULL, FALSE); \
1547 if ((v = gst_tag_list_get_value_index (list, tag, index)) == NULL) \
1549 *value = COPY_FUNC (g_value_get_ ## name (v)); \
1553 #define COPY_FUNC /**/
1555 * gst_tag_list_get_boolean:
1556 * @list: a #GstTagList to get the tag from
1557 * @tag: tag to read out
1558 * @value: (out): location for the result
1560 * Copies the contents for the given tag into the value, merging multiple values
1561 * into one if multiple values are associated with the tag.
1563 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1567 * gst_tag_list_get_boolean_index:
1568 * @list: a #GstTagList to get the tag from
1569 * @tag: tag to read out
1570 * @index: number of entry to read out
1571 * @value: (out): location for the result
1573 * Gets the value that is at the given index for the given tag in the given
1576 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1579 TAG_MERGE_FUNCS (boolean, gboolean, TRUE);
1581 * gst_tag_list_get_int:
1582 * @list: a #GstTagList to get the tag from
1583 * @tag: tag to read out
1584 * @value: (out): location for the result
1586 * Copies the contents for the given tag into the value, merging multiple values
1587 * into one if multiple values are associated with the tag.
1589 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1593 * gst_tag_list_get_int_index:
1594 * @list: a #GstTagList to get the tag from
1595 * @tag: tag to read out
1596 * @index: number of entry to read out
1597 * @value: (out): location for the result
1599 * Gets the value that is at the given index for the given tag in the given
1602 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1605 TAG_MERGE_FUNCS (int, gint, TRUE);
1607 * gst_tag_list_get_uint:
1608 * @list: a #GstTagList to get the tag from
1609 * @tag: tag to read out
1610 * @value: (out): location for the result
1612 * Copies the contents for the given tag into the value, merging multiple values
1613 * into one if multiple values are associated with the tag.
1615 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1619 * gst_tag_list_get_uint_index:
1620 * @list: a #GstTagList to get the tag from
1621 * @tag: tag to read out
1622 * @index: number of entry to read out
1623 * @value: (out): location for the result
1625 * Gets the value that is at the given index for the given tag in the given
1628 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1631 TAG_MERGE_FUNCS (uint, guint, TRUE);
1633 * gst_tag_list_get_int64_index:
1634 * @list: a #GstTagList to get the tag from
1635 * @tag: tag to read out
1636 * @index: number of entry to read out
1637 * @value: (out): location for the result
1639 * Gets the value that is at the given index for the given tag in the given
1642 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1645 TAG_MERGE_FUNCS (int64, gint64, TRUE);
1647 * gst_tag_list_get_uint64:
1648 * @list: a #GstTagList to get the tag from
1649 * @tag: tag to read out
1650 * @value: (out): location for the result
1652 * Copies the contents for the given tag into the value, merging multiple values
1653 * into one if multiple values are associated with the tag.
1655 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1659 * gst_tag_list_get_uint64_index:
1660 * @list: a #GstTagList to get the tag from
1661 * @tag: tag to read out
1662 * @index: number of entry to read out
1663 * @value: (out): location for the result
1665 * Gets the value that is at the given index for the given tag in the given
1668 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1671 TAG_MERGE_FUNCS (uint64, guint64, TRUE);
1673 * gst_tag_list_get_float:
1674 * @list: a #GstTagList to get the tag from
1675 * @tag: tag to read out
1676 * @value: (out): location for the result
1678 * Copies the contents for the given tag into the value, merging multiple values
1679 * into one if multiple values are associated with the tag.
1681 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1685 * gst_tag_list_get_float_index:
1686 * @list: a #GstTagList to get the tag from
1687 * @tag: tag to read out
1688 * @index: number of entry to read out
1689 * @value: (out): location for the result
1691 * Gets the value that is at the given index for the given tag in the given
1694 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1697 TAG_MERGE_FUNCS (float, gfloat, TRUE);
1699 * gst_tag_list_get_double:
1700 * @list: a #GstTagList to get the tag from
1701 * @tag: tag to read out
1702 * @value: (out): location for the result
1704 * Copies the contents for the given tag into the value, merging multiple values
1705 * into one if multiple values are associated with the tag.
1707 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1711 * gst_tag_list_get_double_index:
1712 * @list: a #GstTagList to get the tag from
1713 * @tag: tag to read out
1714 * @index: number of entry to read out
1715 * @value: (out): location for the result
1717 * Gets the value that is at the given index for the given tag in the given
1720 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1723 TAG_MERGE_FUNCS (double, gdouble, TRUE);
1725 * gst_tag_list_get_pointer:
1726 * @list: a #GstTagList to get the tag from
1727 * @tag: tag to read out
1728 * @value: (out) (transfer none): location for the result
1730 * Copies the contents for the given tag into the value, merging multiple values
1731 * into one if multiple values are associated with the tag.
1733 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1737 * gst_tag_list_get_pointer_index:
1738 * @list: a #GstTagList to get the tag from
1739 * @tag: tag to read out
1740 * @index: number of entry to read out
1741 * @value: (out) (transfer none): location for the result
1743 * Gets the value that is at the given index for the given tag in the given
1746 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1749 TAG_MERGE_FUNCS (pointer, gpointer, (*value != NULL));
1751 static inline gchar *
1752 _gst_strdup0 (const gchar * s)
1754 if (s == NULL || *s == '\0')
1757 return g_strdup (s);
1761 #define COPY_FUNC _gst_strdup0
1764 * gst_tag_list_get_string:
1765 * @list: a #GstTagList to get the tag from
1766 * @tag: tag to read out
1767 * @value: (out callee-allocates) (transfer full): location for the result
1769 * Copies the contents for the given tag into the value, possibly merging
1770 * multiple values into one if multiple values are associated with the tag.
1772 * Use gst_tag_list_get_string_index (list, tag, 0, value) if you want
1773 * to retrieve the first string associated with this tag unmodified.
1775 * The resulting string in @value will be in UTF-8 encoding and should be
1776 * freed by the caller using g_free when no longer needed. The
1777 * returned string is also guaranteed to be non-%NULL and non-empty.
1779 * Free-function: g_free
1781 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1785 * gst_tag_list_get_string_index:
1786 * @list: a #GstTagList to get the tag from
1787 * @tag: tag to read out
1788 * @index: number of entry to read out
1789 * @value: (out callee-allocates) (transfer full): location for the result
1791 * Gets the value that is at the given index for the given tag in the given
1794 * The resulting string in @value will be in UTF-8 encoding and should be
1795 * freed by the caller using g_free when no longer needed. The
1796 * returned string is also guaranteed to be non-%NULL and non-empty.
1798 * Free-function: g_free
1800 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1803 TAG_MERGE_FUNCS (string, gchar *, (*value != NULL));
1806 *FIXME 2.0: Instead of _peek (non-copy) and _get (copy), we could have
1807 * _get (non-copy) and _dup (copy) for strings, seems more
1811 * gst_tag_list_peek_string_index:
1812 * @list: a #GstTagList to get the tag from
1813 * @tag: tag to read out
1814 * @index: number of entry to read out
1815 * @value: (out) (transfer none): location for the result
1817 * Peeks at the value that is at the given index for the given tag in the given
1820 * The resulting string in @value will be in UTF-8 encoding and doesn't need
1821 * to be freed by the caller. The returned string is also guaranteed to
1822 * be non-%NULL and non-empty.
1824 * Returns: %TRUE, if a value was set, %FALSE if the tag didn't exist in the
1828 gst_tag_list_peek_string_index (const GstTagList * list,
1829 const gchar * tag, guint index, const gchar ** value)
1833 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1834 g_return_val_if_fail (tag != NULL, FALSE);
1835 g_return_val_if_fail (value != NULL, FALSE);
1837 if ((v = gst_tag_list_get_value_index (list, tag, index)) == NULL)
1839 *value = g_value_get_string (v);
1840 return *value != NULL && **value != '\0';
1844 * gst_tag_list_get_date:
1845 * @list: a #GstTagList to get the tag from
1846 * @tag: tag to read out
1847 * @value: (out callee-allocates) (transfer full): address of a GDate pointer
1848 * variable to store the result into
1850 * Copies the first date for the given tag in the taglist into the variable
1851 * pointed to by @value. Free the date with g_date_free() when it is no longer
1854 * Free-function: g_date_free
1856 * Returns: %TRUE, if a date was copied, %FALSE if the tag didn't exist in the
1857 * given list or if it was %NULL.
1860 gst_tag_list_get_date (const GstTagList * list, const gchar * tag,
1865 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1866 g_return_val_if_fail (tag != NULL, FALSE);
1867 g_return_val_if_fail (value != NULL, FALSE);
1869 if (!gst_tag_list_copy_value (&v, list, tag))
1871 *value = (GDate *) g_value_dup_boxed (&v);
1873 return (*value != NULL);
1877 * gst_tag_list_get_date_index:
1878 * @list: a #GstTagList to get the tag from
1879 * @tag: tag to read out
1880 * @index: number of entry to read out
1881 * @value: (out callee-allocates) (transfer full): location for the result
1883 * Gets the date that is at the given index for the given tag in the given
1884 * list and copies it into the variable pointed to by @value. Free the date
1885 * with g_date_free() when it is no longer needed.
1887 * Free-function: g_date_free
1889 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1890 * given list or if it was %NULL.
1893 gst_tag_list_get_date_index (const GstTagList * list,
1894 const gchar * tag, guint index, GDate ** value)
1898 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1899 g_return_val_if_fail (tag != NULL, FALSE);
1900 g_return_val_if_fail (value != NULL, FALSE);
1902 if ((v = gst_tag_list_get_value_index (list, tag, index)) == NULL)
1904 *value = (GDate *) g_value_dup_boxed (v);
1905 return (*value != NULL);
1909 * gst_tag_list_get_date_time:
1910 * @list: a #GstTagList to get the tag from
1911 * @tag: tag to read out
1912 * @value: (out callee-allocates) (transfer full): address of a #GstDateTime
1913 * pointer variable to store the result into
1915 * Copies the first datetime for the given tag in the taglist into the variable
1916 * pointed to by @value. Unref the date with gst_date_time_unref() when
1917 * it is no longer needed.
1919 * Free-function: gst_date_time_unref
1921 * Returns: %TRUE, if a datetime was copied, %FALSE if the tag didn't exist in
1922 * the given list or if it was %NULL.
1925 gst_tag_list_get_date_time (const GstTagList * list, const gchar * tag,
1926 GstDateTime ** value)
1930 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1931 g_return_val_if_fail (tag != NULL, FALSE);
1932 g_return_val_if_fail (value != NULL, FALSE);
1934 if (!gst_tag_list_copy_value (&v, list, tag))
1937 *value = (GstDateTime *) g_value_dup_boxed (&v);
1939 return (*value != NULL);
1943 * gst_tag_list_get_date_time_index:
1944 * @list: a #GstTagList to get the tag from
1945 * @tag: tag to read out
1946 * @index: number of entry to read out
1947 * @value: (out callee-allocates) (transfer full): location for the result
1949 * Gets the datetime that is at the given index for the given tag in the given
1950 * list and copies it into the variable pointed to by @value. Unref the datetime
1951 * with gst_date_time_unref() when it is no longer needed.
1953 * Free-function: gst_date_time_unref
1955 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1956 * given list or if it was %NULL.
1959 gst_tag_list_get_date_time_index (const GstTagList * list,
1960 const gchar * tag, guint index, GstDateTime ** value)
1964 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1965 g_return_val_if_fail (tag != NULL, FALSE);
1966 g_return_val_if_fail (value != NULL, FALSE);
1968 if ((v = gst_tag_list_get_value_index (list, tag, index)) == NULL)
1970 *value = (GstDateTime *) g_value_dup_boxed (v);
1971 return (*value != NULL);
1975 * gst_tag_list_get_sample:
1976 * @list: a #GstTagList to get the tag from
1977 * @tag: tag to read out
1978 * @sample: (out callee-allocates) (transfer full): address of a GstSample
1979 * pointer variable to store the result into
1981 * Copies the first sample for the given tag in the taglist into the variable
1982 * pointed to by @sample. Free the sample with gst_sample_unref() when it is
1983 * no longer needed. You can retrieve the buffer from the sample using
1984 * gst_sample_get_buffer() and the associated caps (if any) with
1985 * gst_sample_get_caps().
1987 * Free-function: gst_sample_unref
1989 * Returns: %TRUE, if a sample was returned, %FALSE if the tag didn't exist in
1990 * the given list or if it was %NULL.
1993 gst_tag_list_get_sample (const GstTagList * list, const gchar * tag,
1994 GstSample ** sample)
1998 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1999 g_return_val_if_fail (tag != NULL, FALSE);
2000 g_return_val_if_fail (sample != NULL, FALSE);
2002 if (!gst_tag_list_copy_value (&v, list, tag))
2004 *sample = g_value_dup_boxed (&v);
2006 return (*sample != NULL);
2010 * gst_tag_list_get_sample_index:
2011 * @list: a #GstTagList to get the tag from
2012 * @tag: tag to read out
2013 * @index: number of entry to read out
2014 * @sample: (out callee-allocates) (transfer full): address of a GstSample
2015 * pointer variable to store the result into
2017 * Gets the sample that is at the given index for the given tag in the given
2018 * list and copies it into the variable pointed to by @sample. Free the sample
2019 * with gst_sample_unref() when it is no longer needed. You can retrieve the
2020 * buffer from the sample using gst_sample_get_buffer() and the associated
2021 * caps (if any) with gst_sample_get_caps().
2023 * Free-function: gst_sample_unref
2025 * Returns: %TRUE, if a sample was copied, %FALSE if the tag didn't exist in the
2026 * given list or if it was %NULL.
2029 gst_tag_list_get_sample_index (const GstTagList * list,
2030 const gchar * tag, guint index, GstSample ** sample)
2034 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
2035 g_return_val_if_fail (tag != NULL, FALSE);
2036 g_return_val_if_fail (sample != NULL, FALSE);
2038 if ((v = gst_tag_list_get_value_index (list, tag, index)) == NULL)
2040 *sample = g_value_dup_boxed (v);
2041 return (*sample != NULL);