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.
25 * @short_description: List of tags and values used to describe media metadata
27 * List of tags and values used to describe media metadata.
29 * Strings in structures must be ASCII or UTF-8 encoded. Other encodings are
30 * not allowed. Strings must not be empty or %NULL.
37 #include "gst_private.h"
38 #include "math-compat.h"
39 #include "gst-i18n-lib.h"
40 #include "gsttaglist.h"
43 #include "gstbuffer.h"
45 #include "gststructure.h"
47 #include <gobject/gvaluecollector.h>
50 /* FIXME: add category for tags */
51 #define GST_CAT_TAGS GST_CAT_DEFAULT
53 #define GST_TAG_IS_VALID(tag) (gst_tag_get_info (tag) != NULL)
55 typedef struct _GstTagListImpl
59 GstStructure *structure;
63 #define GST_TAG_LIST_STRUCTURE(taglist) ((GstTagListImpl*)(taglist))->structure
64 #define GST_TAG_LIST_SCOPE(taglist) ((GstTagListImpl*)(taglist))->scope
68 GType type; /* type the data is in */
70 const gchar *nick; /* translated short description */
71 const gchar *blurb; /* translated long description */
73 GstTagMergeFunc merge_func; /* functions to merge the values */
74 GstTagFlag flag; /* type of tag */
75 GQuark name_quark; /* quark for the name */
79 #define g_value_get_char g_value_get_schar
81 static GMutex __tag_mutex;
82 #define TAG_LOCK g_mutex_lock (&__tag_mutex)
83 #define TAG_UNLOCK g_mutex_unlock (&__tag_mutex)
85 /* tags hash table: maps tag name string => GstTagInfo */
86 static GHashTable *__tags;
88 GType _gst_tag_list_type = 0;
89 GST_DEFINE_MINI_OBJECT_TYPE (GstTagList, gst_tag_list);
91 static void __gst_tag_list_free (GstTagList * list);
92 static GstTagList *__gst_tag_list_copy (const GstTagList * list);
95 * g_value_register_transform_func (_gst_tag_list_type, G_TYPE_STRING,
96 * _gst_structure_transform_to_string);
99 _priv_gst_tag_initialize (void)
101 g_mutex_init (&__tag_mutex);
103 _gst_tag_list_type = gst_tag_list_get_type ();
105 __tags = g_hash_table_new (g_str_hash, g_str_equal);
106 gst_tag_register_static (GST_TAG_TITLE, GST_TAG_FLAG_META,
108 _("title"), _("commonly used title"), gst_tag_merge_strings_with_comma);
109 gst_tag_register_static (GST_TAG_TITLE_SORTNAME, GST_TAG_FLAG_META,
111 _("title sortname"), _("commonly used title for sorting purposes"), NULL);
112 gst_tag_register_static (GST_TAG_ARTIST, GST_TAG_FLAG_META,
115 _("person(s) responsible for the recording"),
116 gst_tag_merge_strings_with_comma);
117 gst_tag_register_static (GST_TAG_ARTIST_SORTNAME, GST_TAG_FLAG_META,
119 _("artist sortname"),
120 _("person(s) responsible for the recording for sorting purposes"), NULL);
121 gst_tag_register_static (GST_TAG_ALBUM, GST_TAG_FLAG_META,
124 _("album containing this data"), gst_tag_merge_strings_with_comma);
125 gst_tag_register_static (GST_TAG_ALBUM_SORTNAME, GST_TAG_FLAG_META,
128 _("album containing this data for sorting purposes"), NULL);
129 gst_tag_register_static (GST_TAG_ALBUM_ARTIST, GST_TAG_FLAG_META,
132 _("The artist of the entire album, as it should be displayed"),
133 gst_tag_merge_strings_with_comma);
134 gst_tag_register_static (GST_TAG_ALBUM_ARTIST_SORTNAME, GST_TAG_FLAG_META,
136 _("album artist sortname"),
137 _("The artist of the entire album, as it should be sorted"), NULL);
138 gst_tag_register_static (GST_TAG_DATE, GST_TAG_FLAG_META, G_TYPE_DATE,
139 _("date"), _("date the data was created (as a GDate structure)"), NULL);
140 gst_tag_register_static (GST_TAG_DATE_TIME, GST_TAG_FLAG_META,
141 GST_TYPE_DATE_TIME, _("datetime"),
142 _("date and time the data was created (as a GstDateTime structure)"),
144 gst_tag_register_static (GST_TAG_GENRE, GST_TAG_FLAG_META,
147 _("genre this data belongs to"), gst_tag_merge_strings_with_comma);
148 gst_tag_register_static (GST_TAG_COMMENT, GST_TAG_FLAG_META,
151 _("free text commenting the data"), gst_tag_merge_use_first);
152 gst_tag_register_static (GST_TAG_EXTENDED_COMMENT, GST_TAG_FLAG_META,
154 _("extended comment"),
155 _("free text commenting the data in key=value or key[en]=comment form"),
156 gst_tag_merge_use_first);
157 gst_tag_register_static (GST_TAG_TRACK_NUMBER, GST_TAG_FLAG_META,
160 _("track number inside a collection"), gst_tag_merge_use_first);
161 gst_tag_register_static (GST_TAG_TRACK_COUNT, GST_TAG_FLAG_META,
164 _("count of tracks inside collection this track belongs to"),
165 gst_tag_merge_use_first);
166 gst_tag_register_static (GST_TAG_ALBUM_VOLUME_NUMBER, GST_TAG_FLAG_META,
169 _("disc number inside a collection"), gst_tag_merge_use_first);
170 gst_tag_register_static (GST_TAG_ALBUM_VOLUME_COUNT, GST_TAG_FLAG_META,
173 _("count of discs inside collection this disc belongs to"),
174 gst_tag_merge_use_first);
175 gst_tag_register_static (GST_TAG_LOCATION, GST_TAG_FLAG_META,
177 _("location"), _("Origin of media as a URI (location, where the "
178 "original of the file or stream is hosted)"),
179 gst_tag_merge_strings_with_comma);
180 gst_tag_register_static (GST_TAG_HOMEPAGE, GST_TAG_FLAG_META,
183 _("Homepage for this media (i.e. artist or movie homepage)"),
184 gst_tag_merge_strings_with_comma);
185 gst_tag_register_static (GST_TAG_DESCRIPTION, GST_TAG_FLAG_META,
186 G_TYPE_STRING, _("description"),
187 _("short text describing the content of the data"),
188 gst_tag_merge_strings_with_comma);
189 gst_tag_register_static (GST_TAG_VERSION, GST_TAG_FLAG_META, G_TYPE_STRING,
190 _("version"), _("version of this data"), NULL);
191 gst_tag_register_static (GST_TAG_ISRC, GST_TAG_FLAG_META, G_TYPE_STRING,
194 ("International Standard Recording Code - see http://www.ifpi.org/isrc/"),
196 /* FIXME: organization (fix what? tpm) */
197 gst_tag_register_static (GST_TAG_ORGANIZATION, GST_TAG_FLAG_META,
198 G_TYPE_STRING, _("organization"), _("organization"),
199 gst_tag_merge_strings_with_comma);
200 gst_tag_register_static (GST_TAG_COPYRIGHT, GST_TAG_FLAG_META,
201 G_TYPE_STRING, _("copyright"), _("copyright notice of the data"), NULL);
202 gst_tag_register_static (GST_TAG_COPYRIGHT_URI, GST_TAG_FLAG_META,
203 G_TYPE_STRING, _("copyright uri"),
204 _("URI to the copyright notice of the data"), NULL);
205 gst_tag_register_static (GST_TAG_ENCODED_BY, GST_TAG_FLAG_META, G_TYPE_STRING,
206 _("encoded by"), _("name of the encoding person or organization"),
207 gst_tag_merge_strings_with_comma);
208 gst_tag_register_static (GST_TAG_CONTACT, GST_TAG_FLAG_META,
210 _("contact"), _("contact information"), gst_tag_merge_strings_with_comma);
211 gst_tag_register_static (GST_TAG_LICENSE, GST_TAG_FLAG_META,
212 G_TYPE_STRING, _("license"), _("license of data"), NULL);
213 gst_tag_register_static (GST_TAG_LICENSE_URI, GST_TAG_FLAG_META,
214 G_TYPE_STRING, _("license uri"),
215 _("URI to the license of the data"), NULL);
216 gst_tag_register_static (GST_TAG_PERFORMER, GST_TAG_FLAG_META,
219 _("person(s) performing"), gst_tag_merge_strings_with_comma);
220 gst_tag_register_static (GST_TAG_COMPOSER, GST_TAG_FLAG_META,
223 _("person(s) who composed the recording"),
224 gst_tag_merge_strings_with_comma);
225 gst_tag_register_static (GST_TAG_CONDUCTOR, GST_TAG_FLAG_META,
228 _("conductor/performer refinement"), gst_tag_merge_strings_with_comma);
229 gst_tag_register_static (GST_TAG_DURATION, GST_TAG_FLAG_DECODED,
231 _("duration"), _("length in GStreamer time units (nanoseconds)"), NULL);
232 gst_tag_register_static (GST_TAG_CODEC, GST_TAG_FLAG_ENCODED,
235 _("codec the data is stored in"), gst_tag_merge_strings_with_comma);
236 gst_tag_register_static (GST_TAG_VIDEO_CODEC, GST_TAG_FLAG_ENCODED,
238 _("video codec"), _("codec the video data is stored in"), NULL);
239 gst_tag_register_static (GST_TAG_AUDIO_CODEC, GST_TAG_FLAG_ENCODED,
241 _("audio codec"), _("codec the audio data is stored in"), NULL);
242 gst_tag_register_static (GST_TAG_SUBTITLE_CODEC, GST_TAG_FLAG_ENCODED,
244 _("subtitle codec"), _("codec the subtitle data is stored in"), NULL);
245 gst_tag_register_static (GST_TAG_CONTAINER_FORMAT, GST_TAG_FLAG_ENCODED,
246 G_TYPE_STRING, _("container format"),
247 _("container format the data is stored in"), NULL);
248 gst_tag_register_static (GST_TAG_BITRATE, GST_TAG_FLAG_ENCODED,
249 G_TYPE_UINT, _("bitrate"), _("exact or average bitrate in bits/s"), NULL);
250 gst_tag_register_static (GST_TAG_NOMINAL_BITRATE, GST_TAG_FLAG_ENCODED,
251 G_TYPE_UINT, _("nominal bitrate"), _("nominal bitrate in bits/s"), NULL);
252 gst_tag_register_static (GST_TAG_MINIMUM_BITRATE, GST_TAG_FLAG_ENCODED,
253 G_TYPE_UINT, _("minimum bitrate"), _("minimum bitrate in bits/s"), NULL);
254 gst_tag_register_static (GST_TAG_MAXIMUM_BITRATE, GST_TAG_FLAG_ENCODED,
255 G_TYPE_UINT, _("maximum bitrate"), _("maximum bitrate in bits/s"), NULL);
256 gst_tag_register_static (GST_TAG_ENCODER, GST_TAG_FLAG_ENCODED,
258 _("encoder"), _("encoder used to encode this stream"), NULL);
259 gst_tag_register_static (GST_TAG_ENCODER_VERSION, GST_TAG_FLAG_ENCODED,
261 _("encoder version"),
262 _("version of the encoder used to encode this stream"), NULL);
263 gst_tag_register_static (GST_TAG_SERIAL, GST_TAG_FLAG_ENCODED,
264 G_TYPE_UINT, _("serial"), _("serial number of track"), NULL);
265 gst_tag_register_static (GST_TAG_TRACK_GAIN, GST_TAG_FLAG_META,
266 G_TYPE_DOUBLE, _("replaygain track gain"), _("track gain in db"), NULL);
267 gst_tag_register_static (GST_TAG_TRACK_PEAK, GST_TAG_FLAG_META,
268 G_TYPE_DOUBLE, _("replaygain track peak"), _("peak of the track"), NULL);
269 gst_tag_register_static (GST_TAG_ALBUM_GAIN, GST_TAG_FLAG_META,
270 G_TYPE_DOUBLE, _("replaygain album gain"), _("album gain in db"), NULL);
271 gst_tag_register_static (GST_TAG_ALBUM_PEAK, GST_TAG_FLAG_META,
272 G_TYPE_DOUBLE, _("replaygain album peak"), _("peak of the album"), NULL);
273 gst_tag_register_static (GST_TAG_REFERENCE_LEVEL, GST_TAG_FLAG_META,
274 G_TYPE_DOUBLE, _("replaygain reference level"),
275 _("reference level of track and album gain values"), NULL);
276 gst_tag_register_static (GST_TAG_LANGUAGE_CODE, GST_TAG_FLAG_META,
277 G_TYPE_STRING, _("language code"),
278 _("language code for this stream, conforming to ISO-639-1 or ISO-639-2"),
280 gst_tag_register_static (GST_TAG_LANGUAGE_NAME, GST_TAG_FLAG_META,
281 G_TYPE_STRING, _("language name"),
282 _("freeform name of the language this stream is in"), NULL);
283 gst_tag_register_static (GST_TAG_IMAGE, GST_TAG_FLAG_META, GST_TYPE_SAMPLE,
284 _("image"), _("image related to this stream"), gst_tag_merge_use_first);
285 gst_tag_register_static (GST_TAG_PREVIEW_IMAGE, GST_TAG_FLAG_META,
287 /* TRANSLATORS: 'preview image' = image that shows a preview of the full image */
288 _("preview image"), _("preview image related to this stream"), NULL);
289 gst_tag_register_static (GST_TAG_ATTACHMENT, GST_TAG_FLAG_META,
290 GST_TYPE_SAMPLE, _("attachment"), _("file attached to this stream"),
291 gst_tag_merge_use_first);
292 gst_tag_register_static (GST_TAG_BEATS_PER_MINUTE, GST_TAG_FLAG_META,
293 G_TYPE_DOUBLE, _("beats per minute"),
294 _("number of beats per minute in audio"), NULL);
295 gst_tag_register_static (GST_TAG_KEYWORDS, GST_TAG_FLAG_META, G_TYPE_STRING,
296 _("keywords"), _("comma separated keywords describing the content"),
297 gst_tag_merge_strings_with_comma);
298 gst_tag_register_static (GST_TAG_GEO_LOCATION_NAME, GST_TAG_FLAG_META,
299 G_TYPE_STRING, _("geo location name"),
300 _("human readable descriptive location of where "
301 "the media has been recorded or produced"), NULL);
302 gst_tag_register_static (GST_TAG_GEO_LOCATION_LATITUDE, GST_TAG_FLAG_META,
303 G_TYPE_DOUBLE, _("geo location latitude"),
304 _("geo latitude location of where the media has been recorded or "
305 "produced in degrees according to WGS84 (zero at the equator, "
306 "negative values for southern latitudes)"), NULL);
307 gst_tag_register_static (GST_TAG_GEO_LOCATION_LONGITUDE, GST_TAG_FLAG_META,
308 G_TYPE_DOUBLE, _("geo location longitude"),
309 _("geo longitude location of where the media has been recorded or "
310 "produced in degrees according to WGS84 (zero at the prime meridian "
311 "in Greenwich/UK, negative values for western longitudes)"), NULL);
312 gst_tag_register_static (GST_TAG_GEO_LOCATION_ELEVATION, GST_TAG_FLAG_META,
313 G_TYPE_DOUBLE, _("geo location elevation"),
314 _("geo elevation of where the media has been recorded or produced in "
315 "meters according to WGS84 (zero is average sea level)"), NULL);
316 gst_tag_register_static (GST_TAG_GEO_LOCATION_COUNTRY, GST_TAG_FLAG_META,
317 G_TYPE_STRING, _("geo location country"),
318 _("country (english name) where the media has been recorded "
319 "or produced"), NULL);
320 gst_tag_register_static (GST_TAG_GEO_LOCATION_CITY, GST_TAG_FLAG_META,
321 G_TYPE_STRING, _("geo location city"),
322 _("city (english name) where the media has been recorded "
323 "or produced"), NULL);
324 gst_tag_register_static (GST_TAG_GEO_LOCATION_SUBLOCATION, GST_TAG_FLAG_META,
325 G_TYPE_STRING, _("geo location sublocation"),
326 _("a location within a city where the media has been produced "
327 "or created (e.g. the neighborhood)"), NULL);
328 gst_tag_register_static (GST_TAG_GEO_LOCATION_HORIZONTAL_ERROR,
329 GST_TAG_FLAG_META, G_TYPE_DOUBLE, _("geo location horizontal error"),
330 _("expected error of the horizontal positioning measures (in meters)"),
332 gst_tag_register_static (GST_TAG_GEO_LOCATION_MOVEMENT_SPEED,
333 GST_TAG_FLAG_META, G_TYPE_DOUBLE, _("geo location movement speed"),
334 _("movement speed of the capturing device while performing the capture "
336 gst_tag_register_static (GST_TAG_GEO_LOCATION_MOVEMENT_DIRECTION,
337 GST_TAG_FLAG_META, G_TYPE_DOUBLE, _("geo location movement direction"),
338 _("indicates the movement direction of the device performing the capture"
339 " of a media. It is represented as degrees in floating point "
340 "representation, 0 means the geographic north, and increases "
342 gst_tag_register_static (GST_TAG_GEO_LOCATION_CAPTURE_DIRECTION,
343 GST_TAG_FLAG_META, G_TYPE_DOUBLE, _("geo location capture direction"),
344 _("indicates the direction the device is pointing to when capturing "
345 " a media. It is represented as degrees in floating point "
346 " representation, 0 means the geographic north, and increases "
348 gst_tag_register_static (GST_TAG_SHOW_NAME, GST_TAG_FLAG_META, G_TYPE_STRING,
349 /* TRANSLATORS: 'show name' = 'TV/radio/podcast show name' here */
351 _("Name of the tv/podcast/series show the media is from"),
352 gst_tag_merge_strings_with_comma);
353 gst_tag_register_static (GST_TAG_SHOW_SORTNAME, GST_TAG_FLAG_META,
355 /* TRANSLATORS: 'show sortname' = 'TV/radio/podcast show name as used for sorting purposes' here */
357 _("Name of the tv/podcast/series show the media is from, for sorting "
359 gst_tag_register_static (GST_TAG_SHOW_EPISODE_NUMBER, GST_TAG_FLAG_META,
360 G_TYPE_UINT, _("episode number"),
361 _("The episode number in the season the media is part of"),
362 gst_tag_merge_use_first);
363 gst_tag_register_static (GST_TAG_SHOW_SEASON_NUMBER, GST_TAG_FLAG_META,
364 G_TYPE_UINT, _("season number"),
365 _("The season number of the show the media is part of"),
366 gst_tag_merge_use_first);
367 gst_tag_register_static (GST_TAG_LYRICS, GST_TAG_FLAG_META, G_TYPE_STRING,
368 _("lyrics"), _("The lyrics of the media, commonly used for songs"),
369 gst_tag_merge_strings_with_comma);
370 gst_tag_register_static (GST_TAG_COMPOSER_SORTNAME, GST_TAG_FLAG_META,
371 G_TYPE_STRING, _("composer sortname"),
372 _("person(s) who composed the recording, for sorting purposes"), NULL);
373 gst_tag_register_static (GST_TAG_GROUPING, GST_TAG_FLAG_META, G_TYPE_STRING,
375 _("Groups related media that spans multiple tracks, like the different "
376 "pieces of a concerto. It is a higher level than a track, "
377 "but lower than an album"), NULL);
378 gst_tag_register_static (GST_TAG_USER_RATING, GST_TAG_FLAG_META, G_TYPE_UINT,
380 _("Rating attributed by a user. The higher the rank, "
381 "the more the user likes this media"), NULL);
382 gst_tag_register_static (GST_TAG_DEVICE_MANUFACTURER, GST_TAG_FLAG_META,
383 G_TYPE_STRING, _("device manufacturer"),
384 _("Manufacturer of the device used to create this media"), NULL);
385 gst_tag_register_static (GST_TAG_DEVICE_MODEL, GST_TAG_FLAG_META,
386 G_TYPE_STRING, _("device model"),
387 _("Model of the device used to create this media"), NULL);
388 gst_tag_register_static (GST_TAG_APPLICATION_NAME, GST_TAG_FLAG_META,
389 G_TYPE_STRING, _("application name"),
390 _("Application used to create the media"), NULL);
391 gst_tag_register_static (GST_TAG_APPLICATION_DATA, GST_TAG_FLAG_META,
392 GST_TYPE_SAMPLE, _("application data"),
393 _("Arbitrary application data to be serialized into the media"), NULL);
394 gst_tag_register_static (GST_TAG_IMAGE_ORIENTATION, GST_TAG_FLAG_META,
395 G_TYPE_STRING, _("image orientation"),
396 _("How the image should be rotated or flipped before display"), NULL);
397 gst_tag_register_static (GST_TAG_PUBLISHER, GST_TAG_FLAG_META,
400 _("Name of the label or publisher"), gst_tag_merge_strings_with_comma);
401 gst_tag_register_static (GST_TAG_INTERPRETED_BY, GST_TAG_FLAG_META,
404 _("Information about the people behind a remix and similar "
405 "interpretations"), gst_tag_merge_strings_with_comma);
406 gst_tag_register_static (GST_TAG_MIDI_BASE_NOTE, GST_TAG_FLAG_META,
408 _("midi-base-note"), _("Midi note number of the audio track."), NULL);
409 gst_tag_register_static (GST_TAG_PRIVATE_DATA, GST_TAG_FLAG_META,
411 _("private-data"), _("Private data"), gst_tag_merge_use_first);
416 * gst_tag_merge_use_first:
417 * @dest: (out caller-allocates): uninitialized GValue to store result in
418 * @src: GValue to copy from
420 * This is a convenience function for the func argument of gst_tag_register().
421 * It creates a copy of the first value from the list.
424 gst_tag_merge_use_first (GValue * dest, const GValue * src)
426 const GValue *ret = gst_value_list_get_value (src, 0);
428 g_value_init (dest, G_VALUE_TYPE (ret));
429 g_value_copy (ret, dest);
433 * gst_tag_merge_strings_with_comma:
434 * @dest: (out caller-allocates): uninitialized GValue to store result in
435 * @src: GValue to copy from
437 * This is a convenience function for the func argument of gst_tag_register().
438 * It concatenates all given strings using a comma. The tag must be registered
439 * as a G_TYPE_STRING or this function will fail.
442 gst_tag_merge_strings_with_comma (GValue * dest, const GValue * src)
447 count = gst_value_list_get_size (src);
448 str = g_string_new (g_value_get_string (gst_value_list_get_value (src, 0)));
449 for (i = 1; i < count; i++) {
450 /* separator between two strings */
451 g_string_append (str, _(", "));
452 g_string_append (str,
453 g_value_get_string (gst_value_list_get_value (src, i)));
456 g_value_init (dest, G_TYPE_STRING);
457 g_value_take_string (dest, str->str);
458 g_string_free (str, FALSE);
462 gst_tag_lookup (const gchar * tag_name)
467 ret = g_hash_table_lookup (__tags, (gpointer) tag_name);
475 * @name: the name or identifier string
476 * @flag: a flag describing the type of tag info
477 * @type: the type this data is in
478 * @nick: human-readable name
479 * @blurb: a human-readable description about this tag
480 * @func: (allow-none) (scope call): function for merging multiple values of this tag, or %NULL
482 * Registers a new tag type for the use with GStreamer's type system. If a type
483 * with that name is already registered, that one is used.
484 * The old registration may have used a different type however. So don't rely
485 * on your supplied values.
487 * Important: if you do not supply a merge function the implication will be
488 * that there can only be one single value for this tag in a tag list and
489 * any additional values will silently be discarded when being added (unless
490 * #GST_TAG_MERGE_REPLACE, #GST_TAG_MERGE_REPLACE_ALL, or
491 * #GST_TAG_MERGE_PREPEND is used as merge mode, in which case the new
492 * value will replace the old one in the list).
494 * The merge function will be called from gst_tag_list_copy_value() when
495 * it is required that one or more values for a tag be condensed into
496 * one single value. This may happen from gst_tag_list_get_string(),
497 * gst_tag_list_get_int(), gst_tag_list_get_double() etc. What will happen
498 * exactly in that case depends on how the tag was registered and if a
499 * merge function was supplied and if so which one.
501 * Two default merge functions are provided: gst_tag_merge_use_first() and
502 * gst_tag_merge_strings_with_comma().
505 gst_tag_register (const gchar * name, GstTagFlag flag, GType type,
506 const gchar * nick, const gchar * blurb, GstTagMergeFunc func)
508 g_return_if_fail (name != NULL);
509 g_return_if_fail (nick != NULL);
510 g_return_if_fail (blurb != NULL);
511 g_return_if_fail (type != 0 && type != GST_TYPE_LIST);
513 gst_tag_register_static (g_intern_string (name), flag, type,
514 g_intern_string (nick), g_intern_string (blurb), func);
518 * gst_tag_register_static:
519 * @name: the name or identifier string (string constant)
520 * @flag: a flag describing the type of tag info
521 * @type: the type this data is in
522 * @nick: human-readable name or short description (string constant)
523 * @blurb: a human-readable description for this tag (string constant)
524 * @func: (allow-none) (scope call): function for merging multiple values of this tag, or %NULL
526 * Registers a new tag type for the use with GStreamer's type system.
528 * Same as gst_tag_register(), but @name, @nick, and @blurb must be
529 * static strings or inlined strings, as they will not be copied. (GStreamer
530 * plugins will be made resident once loaded, so this function can be used
531 * even from dynamically loaded plugins.)
534 gst_tag_register_static (const gchar * name, GstTagFlag flag, GType type,
535 const gchar * nick, const gchar * blurb, GstTagMergeFunc func)
539 g_return_if_fail (name != NULL);
540 g_return_if_fail (nick != NULL);
541 g_return_if_fail (blurb != NULL);
542 g_return_if_fail (type != 0 && type != GST_TYPE_LIST);
544 info = gst_tag_lookup (name);
547 g_return_if_fail (info->type == type);
551 info = g_slice_new (GstTagInfo);
554 info->name_quark = g_quark_from_static_string (name);
557 info->merge_func = func;
560 g_hash_table_insert (__tags, (gpointer) name, info);
566 * @tag: name of the tag
568 * Checks if the given type is already registered.
570 * Returns: %TRUE if the type is already registered
573 gst_tag_exists (const gchar * tag)
575 g_return_val_if_fail (tag != NULL, FALSE);
577 return gst_tag_lookup (tag) != NULL;
584 * Gets the #GType used for this tag.
586 * Returns: the #GType of this tag
589 gst_tag_get_type (const gchar * tag)
593 g_return_val_if_fail (tag != NULL, 0);
594 info = gst_tag_lookup (tag);
595 g_return_val_if_fail (info != NULL, 0);
604 * Returns the human-readable name of this tag, You must not change or free
607 * Returns: (nullable): the human-readable name of this tag
610 gst_tag_get_nick (const gchar * tag)
614 g_return_val_if_fail (tag != NULL, NULL);
615 info = gst_tag_lookup (tag);
617 GST_WARNING ("Unknown tag: %s", tag);
626 * gst_tag_get_description:
629 * Returns the human-readable description of this tag, You must not change or
632 * Returns: (nullable): the human-readable description of this tag
635 gst_tag_get_description (const gchar * tag)
639 g_return_val_if_fail (tag != NULL, NULL);
640 info = gst_tag_lookup (tag);
641 g_return_val_if_fail (info != NULL, NULL);
650 * Gets the flag of @tag.
652 * Returns: the flag of this tag.
655 gst_tag_get_flag (const gchar * tag)
659 g_return_val_if_fail (tag != NULL, GST_TAG_FLAG_UNDEFINED);
660 info = gst_tag_lookup (tag);
661 g_return_val_if_fail (info != NULL, GST_TAG_FLAG_UNDEFINED);
670 * Checks if the given tag is fixed. A fixed tag can only contain one value.
671 * Unfixed tags can contain lists of values.
673 * Returns: %TRUE, if the given tag is fixed.
676 gst_tag_is_fixed (const gchar * tag)
680 g_return_val_if_fail (tag != NULL, FALSE);
681 info = gst_tag_lookup (tag);
682 g_return_val_if_fail (info != NULL, FALSE);
684 return info->merge_func == NULL;
687 /* takes ownership of the structure */
689 gst_tag_list_new_internal (GstStructure * s, GstTagScope scope)
691 GstTagList *tag_list;
693 g_assert (s != NULL);
695 tag_list = (GstTagList *) g_slice_new (GstTagListImpl);
697 gst_mini_object_init (GST_MINI_OBJECT_CAST (tag_list), 0, GST_TYPE_TAG_LIST,
698 (GstMiniObjectCopyFunction) __gst_tag_list_copy, NULL,
699 (GstMiniObjectFreeFunction) __gst_tag_list_free);
701 GST_TAG_LIST_STRUCTURE (tag_list) = s;
702 GST_TAG_LIST_SCOPE (tag_list) = scope;
704 #ifdef DEBUG_REFCOUNT
705 GST_CAT_TRACE (GST_CAT_TAGS, "created taglist %p", tag_list);
712 __gst_tag_list_free (GstTagList * list)
714 g_return_if_fail (GST_IS_TAG_LIST (list));
716 #ifdef DEBUG_REFCOUNT
717 GST_CAT_TRACE (GST_CAT_TAGS, "freeing taglist %p", list);
720 gst_structure_free (GST_TAG_LIST_STRUCTURE (list));
722 g_slice_free1 (sizeof (GstTagListImpl), list);
726 __gst_tag_list_copy (const GstTagList * list)
728 const GstStructure *s;
730 g_return_val_if_fail (GST_IS_TAG_LIST (list), NULL);
732 s = GST_TAG_LIST_STRUCTURE (list);
733 return gst_tag_list_new_internal (gst_structure_copy (s),
734 GST_TAG_LIST_SCOPE (list));
738 * gst_tag_list_new_empty:
740 * Creates a new empty GstTagList.
742 * Free-function: gst_tag_list_unref
744 * Returns: (transfer full): An empty tag list
747 gst_tag_list_new_empty (void)
750 GstTagList *tag_list;
752 s = gst_structure_new_id_empty (GST_QUARK (TAGLIST));
753 tag_list = gst_tag_list_new_internal (s, GST_TAG_SCOPE_STREAM);
760 * @...: %NULL-terminated list of values to set
762 * Creates a new taglist and appends the values for the given tags. It expects
763 * tag-value pairs like gst_tag_list_add(), and a %NULL terminator after the
764 * last pair. The type of the values is implicit and is documented in the API
765 * reference, but can also be queried at runtime with gst_tag_get_type(). It
766 * is an error to pass a value of a type not matching the tag type into this
767 * function. The tag list will make copies of any arguments passed
768 * (e.g. strings, buffers).
770 * After creation you might also want to set a #GstTagScope on the returned
771 * taglist to signal if the contained tags are global or stream tags. By
772 * default stream scope is assumes. See gst_tag_list_set_scope().
774 * Free-function: gst_tag_list_unref
776 * Returns: (transfer full): a new #GstTagList. Free with gst_tag_list_unref()
777 * when no longer needed.
780 gst_tag_list_new (const gchar * tag, ...)
785 g_return_val_if_fail (tag != NULL, NULL);
787 list = gst_tag_list_new_empty ();
788 va_start (args, tag);
789 gst_tag_list_add_valist (list, GST_TAG_MERGE_APPEND, tag, args);
796 * gst_tag_list_new_valist:
797 * @var_args: tag / value pairs to set
799 * Just like gst_tag_list_new(), only that it takes a va_list argument.
800 * Useful mostly for language bindings.
802 * Free-function: gst_tag_list_unref
804 * Returns: (transfer full): a new #GstTagList. Free with gst_tag_list_unref()
805 * when no longer needed.
808 gst_tag_list_new_valist (va_list var_args)
813 list = gst_tag_list_new_empty ();
815 tag = va_arg (var_args, gchar *);
816 gst_tag_list_add_valist (list, GST_TAG_MERGE_APPEND, tag, var_args);
822 * gst_tag_list_set_scope:
823 * @list: a #GstTagList
824 * @scope: new scope for @list
826 * Sets the scope of @list to @scope. By default the scope
827 * of a taglist is stream scope.
831 gst_tag_list_set_scope (GstTagList * list, GstTagScope scope)
833 g_return_if_fail (GST_IS_TAG_LIST (list));
834 g_return_if_fail (gst_tag_list_is_writable (list));
836 GST_TAG_LIST_SCOPE (list) = scope;
840 * gst_tag_list_get_scope:
841 * @list: a #GstTagList
843 * Gets the scope of @list.
845 * Returns: The scope of @list
848 gst_tag_list_get_scope (const GstTagList * list)
850 g_return_val_if_fail (GST_IS_TAG_LIST (list), GST_TAG_SCOPE_STREAM);
852 return GST_TAG_LIST_SCOPE (list);
856 * gst_tag_list_to_string:
857 * @list: a #GstTagList
859 * Serializes a tag list to a string.
861 * Returns: (nullable): a newly-allocated string, or %NULL in case of
862 * an error. The string must be freed with g_free() when no longer
866 gst_tag_list_to_string (const GstTagList * list)
868 g_return_val_if_fail (GST_IS_TAG_LIST (list), NULL);
870 return gst_structure_to_string (GST_TAG_LIST_STRUCTURE (list));
874 * gst_tag_list_new_from_string:
875 * @str: a string created with gst_tag_list_to_string()
877 * Deserializes a tag list.
879 * Returns: (nullable): a new #GstTagList, or %NULL in case of an
883 gst_tag_list_new_from_string (const gchar * str)
885 GstTagList *tag_list;
888 g_return_val_if_fail (str != NULL, NULL);
889 g_return_val_if_fail (g_str_has_prefix (str, "taglist"), NULL);
891 s = gst_structure_from_string (str, NULL);
895 tag_list = gst_tag_list_new_internal (s, GST_TAG_SCOPE_STREAM);
901 * gst_tag_list_n_tags:
902 * @list: A #GstTagList.
904 * Get the number of tags in @list.
906 * Returns: The number of tags in @list.
909 gst_tag_list_n_tags (const GstTagList * list)
911 g_return_val_if_fail (list != NULL, 0);
912 g_return_val_if_fail (GST_IS_TAG_LIST (list), 0);
914 return gst_structure_n_fields (GST_TAG_LIST_STRUCTURE (list));
918 * gst_tag_list_nth_tag_name:
919 * @list: A #GstTagList.
922 * Get the name of the tag in @list at @index.
924 * Returns: The name of the tag at @index.
927 gst_tag_list_nth_tag_name (const GstTagList * list, guint index)
929 g_return_val_if_fail (list != NULL, 0);
930 g_return_val_if_fail (GST_IS_TAG_LIST (list), 0);
932 return gst_structure_nth_field_name (GST_TAG_LIST_STRUCTURE (list), index);
936 * gst_tag_list_is_empty:
937 * @list: A #GstTagList.
939 * Checks if the given taglist is empty.
941 * Returns: %TRUE if the taglist is empty, otherwise %FALSE.
944 gst_tag_list_is_empty (const GstTagList * list)
946 g_return_val_if_fail (list != NULL, FALSE);
947 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
949 return (gst_structure_n_fields (GST_TAG_LIST_STRUCTURE (list)) == 0);
953 gst_tag_list_fields_equal (const GValue * value1, const GValue * value2)
957 if (gst_value_compare (value1, value2) == GST_VALUE_EQUAL)
960 /* fields not equal: add some tolerance for doubles, otherwise bail out */
961 if (!G_VALUE_HOLDS_DOUBLE (value1) || !G_VALUE_HOLDS_DOUBLE (value2))
964 d1 = g_value_get_double (value1);
965 d2 = g_value_get_double (value2);
967 /* This will only work for 'normal' values and values around 0,
968 * which should be good enough for our purposes here
969 * FIXME: maybe add this to gst_value_compare_double() ? */
970 return (fabs (d1 - d2) < 0.0000001);
974 * gst_tag_list_is_equal:
975 * @list1: a #GstTagList.
976 * @list2: a #GstTagList.
978 * Checks if the two given taglists are equal.
980 * Returns: %TRUE if the taglists are equal, otherwise %FALSE
983 gst_tag_list_is_equal (const GstTagList * list1, const GstTagList * list2)
985 const GstStructure *s1, *s2;
986 gint num_fields1, num_fields2, i;
988 g_return_val_if_fail (GST_IS_TAG_LIST (list1), FALSE);
989 g_return_val_if_fail (GST_IS_TAG_LIST (list2), FALSE);
991 /* we don't just use gst_structure_is_equal() here so we can add some
992 * tolerance for doubles, though maybe we should just add that to
993 * gst_value_compare_double() as well? */
994 s1 = GST_TAG_LIST_STRUCTURE (list1);
995 s2 = GST_TAG_LIST_STRUCTURE (list2);
997 num_fields1 = gst_structure_n_fields (s1);
998 num_fields2 = gst_structure_n_fields (s2);
1000 if (num_fields1 != num_fields2)
1003 for (i = 0; i < num_fields1; i++) {
1004 const GValue *value1, *value2;
1005 const gchar *tag_name;
1007 tag_name = gst_structure_nth_field_name (s1, i);
1008 value1 = gst_structure_get_value (s1, tag_name);
1009 value2 = gst_structure_get_value (s2, tag_name);
1014 if (!gst_tag_list_fields_equal (value1, value2))
1024 GstTagMergeMode mode;
1029 gst_tag_list_add_value_internal (GstTagList * tag_list, GstTagMergeMode mode,
1030 const gchar * tag, const GValue * value, GstTagInfo * info)
1032 GstStructure *list = GST_TAG_LIST_STRUCTURE (tag_list);
1033 const GValue *value2;
1037 info = gst_tag_lookup (tag);
1038 if (G_UNLIKELY (info == NULL)) {
1039 g_warning ("unknown tag '%s'", tag);
1044 if (G_UNLIKELY (!G_VALUE_HOLDS (value, info->type) &&
1045 !GST_VALUE_HOLDS_LIST (value))) {
1046 g_warning ("tag '%s' should hold value of type '%s', but value of "
1047 "type '%s' passed", info->nick, g_type_name (info->type),
1048 g_type_name (G_VALUE_TYPE (value)));
1052 tag_quark = info->name_quark;
1054 if (info->merge_func
1055 && (value2 = gst_structure_id_get_value (list, tag_quark)) != NULL) {
1056 GValue dest = { 0, };
1059 case GST_TAG_MERGE_REPLACE_ALL:
1060 case GST_TAG_MERGE_REPLACE:
1061 gst_structure_id_set_value (list, tag_quark, value);
1063 case GST_TAG_MERGE_PREPEND:
1064 if (GST_VALUE_HOLDS_LIST (value2) && !GST_VALUE_HOLDS_LIST (value))
1065 gst_value_list_prepend_value ((GValue *) value2, value);
1067 gst_value_list_merge (&dest, value, value2);
1068 gst_structure_id_take_value (list, tag_quark, &dest);
1071 case GST_TAG_MERGE_APPEND:
1072 if (GST_VALUE_HOLDS_LIST (value2) && !GST_VALUE_HOLDS_LIST (value))
1073 gst_value_list_append_value ((GValue *) value2, value);
1075 gst_value_list_merge (&dest, value2, value);
1076 gst_structure_id_take_value (list, tag_quark, &dest);
1079 case GST_TAG_MERGE_KEEP:
1080 case GST_TAG_MERGE_KEEP_ALL:
1083 g_assert_not_reached ();
1088 case GST_TAG_MERGE_APPEND:
1089 case GST_TAG_MERGE_KEEP:
1090 if (gst_structure_id_get_value (list, tag_quark) != NULL)
1093 case GST_TAG_MERGE_REPLACE_ALL:
1094 case GST_TAG_MERGE_REPLACE:
1095 case GST_TAG_MERGE_PREPEND:
1096 gst_structure_id_set_value (list, tag_quark, value);
1098 case GST_TAG_MERGE_KEEP_ALL:
1101 g_assert_not_reached ();
1108 gst_tag_list_copy_foreach (GQuark tag_quark, const GValue * value,
1111 GstTagCopyData *copy = (GstTagCopyData *) user_data;
1114 tag = g_quark_to_string (tag_quark);
1115 gst_tag_list_add_value_internal (copy->list, copy->mode, tag, value, NULL);
1121 * gst_tag_list_insert:
1122 * @into: list to merge into
1123 * @from: list to merge from
1124 * @mode: the mode to use
1126 * Inserts the tags of the @from list into the first list using the given mode.
1129 gst_tag_list_insert (GstTagList * into, const GstTagList * from,
1130 GstTagMergeMode mode)
1132 GstTagCopyData data;
1134 g_return_if_fail (GST_IS_TAG_LIST (into));
1135 g_return_if_fail (gst_tag_list_is_writable (into));
1136 g_return_if_fail (GST_IS_TAG_LIST (from));
1137 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1141 if (mode == GST_TAG_MERGE_REPLACE_ALL) {
1142 gst_structure_remove_all_fields (GST_TAG_LIST_STRUCTURE (into));
1144 gst_structure_foreach (GST_TAG_LIST_STRUCTURE (from),
1145 gst_tag_list_copy_foreach, &data);
1149 * gst_tag_list_merge:
1150 * @list1: (allow-none): first list to merge
1151 * @list2: (allow-none): second list to merge
1152 * @mode: the mode to use
1154 * Merges the two given lists into a new list. If one of the lists is %NULL, a
1155 * copy of the other is returned. If both lists are %NULL, %NULL is returned.
1157 * Free-function: gst_tag_list_unref
1159 * Returns: (transfer full) (nullable): the new list
1162 gst_tag_list_merge (const GstTagList * list1, const GstTagList * list2,
1163 GstTagMergeMode mode)
1165 GstTagList *list1_cp;
1166 const GstTagList *list2_cp;
1168 g_return_val_if_fail (list1 == NULL || GST_IS_TAG_LIST (list1), NULL);
1169 g_return_val_if_fail (list2 == NULL || GST_IS_TAG_LIST (list2), NULL);
1170 g_return_val_if_fail (GST_TAG_MODE_IS_VALID (mode), NULL);
1172 /* nothing to merge */
1173 if (!list1 && !list2) {
1177 /* create empty list, we need to do this to correctly handling merge modes */
1178 list1_cp = (list1) ? gst_tag_list_copy (list1) : gst_tag_list_new_empty ();
1179 list2_cp = (list2) ? list2 : gst_tag_list_new_empty ();
1181 gst_tag_list_insert (list1_cp, list2_cp, mode);
1184 gst_tag_list_unref ((GstTagList *) list2_cp);
1190 * gst_tag_list_get_tag_size:
1192 * @tag: the tag to query
1194 * Checks how many value are stored in this tag list for the given tag.
1196 * Returns: The number of tags stored
1199 gst_tag_list_get_tag_size (const GstTagList * list, const gchar * tag)
1201 const GValue *value;
1203 g_return_val_if_fail (GST_IS_TAG_LIST (list), 0);
1205 value = gst_structure_get_value (GST_TAG_LIST_STRUCTURE (list), tag);
1208 if (G_VALUE_TYPE (value) != GST_TYPE_LIST)
1211 return gst_value_list_get_size (value);
1216 * @list: list to set tags in
1217 * @mode: the mode to use
1219 * @...: %NULL-terminated list of values to set
1221 * Sets the values for the given tags using the specified mode.
1224 gst_tag_list_add (GstTagList * list, GstTagMergeMode mode, const gchar * tag,
1229 g_return_if_fail (GST_IS_TAG_LIST (list));
1230 g_return_if_fail (gst_tag_list_is_writable (list));
1231 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1232 g_return_if_fail (tag != NULL);
1234 va_start (args, tag);
1235 gst_tag_list_add_valist (list, mode, tag, args);
1240 * gst_tag_list_add_values:
1241 * @list: list to set tags in
1242 * @mode: the mode to use
1244 * @...: GValues to set
1246 * Sets the GValues for the given tags using the specified mode.
1249 gst_tag_list_add_values (GstTagList * list, GstTagMergeMode mode,
1250 const gchar * tag, ...)
1254 g_return_if_fail (GST_IS_TAG_LIST (list));
1255 g_return_if_fail (gst_tag_list_is_writable (list));
1256 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1257 g_return_if_fail (tag != NULL);
1259 va_start (args, tag);
1260 gst_tag_list_add_valist_values (list, mode, tag, args);
1265 * gst_tag_list_add_valist:
1266 * @list: list to set tags in
1267 * @mode: the mode to use
1269 * @var_args: tag / value pairs to set
1271 * Sets the values for the given tags using the specified mode.
1274 gst_tag_list_add_valist (GstTagList * list, GstTagMergeMode mode,
1275 const gchar * tag, va_list var_args)
1278 gchar *error = NULL;
1280 g_return_if_fail (GST_IS_TAG_LIST (list));
1281 g_return_if_fail (gst_tag_list_is_writable (list));
1282 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1283 g_return_if_fail (tag != NULL);
1285 if (mode == GST_TAG_MERGE_REPLACE_ALL) {
1286 gst_structure_remove_all_fields (GST_TAG_LIST_STRUCTURE (list));
1289 while (tag != NULL) {
1290 GValue value = { 0, };
1292 info = gst_tag_lookup (tag);
1293 if (G_UNLIKELY (info == NULL)) {
1294 g_warning ("unknown tag '%s'", tag);
1297 G_VALUE_COLLECT_INIT (&value, info->type, var_args, 0, &error);
1299 g_warning ("%s: %s", G_STRLOC, error);
1301 /* we purposely leak the value here, it might not be
1302 * in a sane state if an error condition occurred
1306 /* Facilitate GstBuffer -> GstSample transition */
1307 if (G_UNLIKELY (info->type == GST_TYPE_SAMPLE &&
1308 !GST_IS_SAMPLE (value.data[0].v_pointer))) {
1309 g_warning ("Expected GstSample argument for tag '%s'", tag);
1311 gst_tag_list_add_value_internal (list, mode, tag, &value, info);
1313 g_value_unset (&value);
1314 tag = va_arg (var_args, gchar *);
1319 * gst_tag_list_add_valist_values:
1320 * @list: list to set tags in
1321 * @mode: the mode to use
1323 * @var_args: tag / GValue pairs to set
1325 * Sets the GValues for the given tags using the specified mode.
1328 gst_tag_list_add_valist_values (GstTagList * list, GstTagMergeMode mode,
1329 const gchar * tag, va_list var_args)
1331 g_return_if_fail (GST_IS_TAG_LIST (list));
1332 g_return_if_fail (gst_tag_list_is_writable (list));
1333 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1334 g_return_if_fail (tag != NULL);
1336 if (mode == GST_TAG_MERGE_REPLACE_ALL) {
1337 gst_structure_remove_all_fields (GST_TAG_LIST_STRUCTURE (list));
1340 while (tag != NULL) {
1343 info = gst_tag_lookup (tag);
1344 if (G_UNLIKELY (info == NULL)) {
1345 g_warning ("unknown tag '%s'", tag);
1348 gst_tag_list_add_value_internal (list, mode, tag, va_arg (var_args,
1350 tag = va_arg (var_args, gchar *);
1355 * gst_tag_list_add_value:
1356 * @list: list to set tags in
1357 * @mode: the mode to use
1359 * @value: GValue for this tag
1361 * Sets the GValue for a given tag using the specified mode.
1364 gst_tag_list_add_value (GstTagList * list, GstTagMergeMode mode,
1365 const gchar * tag, const GValue * value)
1367 g_return_if_fail (GST_IS_TAG_LIST (list));
1368 g_return_if_fail (gst_tag_list_is_writable (list));
1369 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1370 g_return_if_fail (tag != NULL);
1372 gst_tag_list_add_value_internal (list, mode, tag, value, NULL);
1376 * gst_tag_list_remove_tag:
1377 * @list: list to remove tag from
1378 * @tag: tag to remove
1380 * Removes the given tag from the taglist.
1383 gst_tag_list_remove_tag (GstTagList * list, const gchar * tag)
1385 g_return_if_fail (GST_IS_TAG_LIST (list));
1386 g_return_if_fail (gst_tag_list_is_writable (list));
1387 g_return_if_fail (tag != NULL);
1389 gst_structure_remove_field (GST_TAG_LIST_STRUCTURE (list), tag);
1394 GstTagForeachFunc func;
1395 const GstTagList *tag_list;
1401 structure_foreach_wrapper (GQuark field_id, const GValue * value,
1404 TagForeachData *data = (TagForeachData *) user_data;
1406 data->func (data->tag_list, g_quark_to_string (field_id), data->data);
1411 * gst_tag_list_foreach:
1412 * @list: list to iterate over
1413 * @func: (scope call): function to be called for each tag
1414 * @user_data: (closure): user specified data
1416 * Calls the given function for each tag inside the tag list. Note that if there
1417 * is no tag, the function won't be called at all.
1420 gst_tag_list_foreach (const GstTagList * list, GstTagForeachFunc func,
1423 TagForeachData data;
1425 g_return_if_fail (GST_IS_TAG_LIST (list));
1426 g_return_if_fail (func != NULL);
1429 data.tag_list = list;
1430 data.data = user_data;
1431 gst_structure_foreach (GST_TAG_LIST_STRUCTURE (list),
1432 structure_foreach_wrapper, &data);
1436 * gst_tag_list_get_value_index:
1437 * @list: a #GstTagList
1438 * @tag: tag to read out
1439 * @index: number of entry to read out
1441 * Gets the value that is at the given index for the given tag in the given
1444 * Returns: (transfer none) (nullable): The GValue for the specified
1445 * entry or %NULL if the tag wasn't available or the tag
1446 * doesn't have as many entries
1449 gst_tag_list_get_value_index (const GstTagList * list, const gchar * tag,
1452 const GValue *value;
1454 g_return_val_if_fail (GST_IS_TAG_LIST (list), NULL);
1455 g_return_val_if_fail (tag != NULL, NULL);
1457 value = gst_structure_get_value (GST_TAG_LIST_STRUCTURE (list), tag);
1461 if (GST_VALUE_HOLDS_LIST (value)) {
1462 if (index >= gst_value_list_get_size (value))
1464 return gst_value_list_get_value (value, index);
1473 * gst_tag_list_copy_value:
1474 * @dest: (out caller-allocates): uninitialized #GValue to copy into
1475 * @list: list to get the tag from
1476 * @tag: tag to read out
1478 * Copies the contents for the given tag into the value,
1479 * merging multiple values into one if multiple values are associated
1481 * You must g_value_unset() the value after use.
1483 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1487 gst_tag_list_copy_value (GValue * dest, const GstTagList * list,
1492 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1493 g_return_val_if_fail (tag != NULL, FALSE);
1494 g_return_val_if_fail (dest != NULL, FALSE);
1495 g_return_val_if_fail (G_VALUE_TYPE (dest) == 0, FALSE);
1497 src = gst_structure_get_value (GST_TAG_LIST_STRUCTURE (list), tag);
1501 if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
1502 GstTagInfo *info = gst_tag_lookup (tag);
1507 /* must be there or lists aren't allowed */
1508 g_assert (info->merge_func);
1509 info->merge_func (dest, src);
1511 g_value_init (dest, G_VALUE_TYPE (src));
1512 g_value_copy (src, dest);
1517 /* FIXME 2.0: this whole merge function business is overdesigned, and the
1518 * _get_foo() API is misleading as well - how many application developers will
1519 * expect gst_tag_list_get_string (list, GST_TAG_ARTIST, &val) might return a
1520 * string with multiple comma-separated artists? _get_foo() should just be
1521 * a convenience wrapper around _get_foo_index (list, tag, 0, &val),
1522 * supplemented by a special _tag_list_get_string_merged() function if needed
1523 * (unless someone can actually think of real use cases where the merge
1524 * function is not 'use first' for non-strings and merge for strings) */
1526 /***** evil macros to get all the gst_tag_list_get_*() functions right *****/
1528 #define TAG_MERGE_FUNCS(name,type,ret) \
1530 gst_tag_list_get_ ## name (const GstTagList *list, const gchar *tag, \
1533 GValue v = { 0, }; \
1535 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE); \
1536 g_return_val_if_fail (tag != NULL, FALSE); \
1537 g_return_val_if_fail (value != NULL, FALSE); \
1539 if (!gst_tag_list_copy_value (&v, list, tag)) \
1541 *value = COPY_FUNC (g_value_get_ ## name (&v)); \
1542 g_value_unset (&v); \
1547 gst_tag_list_get_ ## name ## _index (const GstTagList *list, \
1549 guint index, type *value) \
1553 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE); \
1554 g_return_val_if_fail (tag != NULL, FALSE); \
1555 g_return_val_if_fail (value != NULL, FALSE); \
1557 if ((v = gst_tag_list_get_value_index (list, tag, index)) == NULL) \
1559 *value = COPY_FUNC (g_value_get_ ## name (v)); \
1563 #define COPY_FUNC /**/
1565 * gst_tag_list_get_boolean:
1566 * @list: a #GstTagList to get the tag from
1567 * @tag: tag to read out
1568 * @value: (out): location for the result
1570 * Copies the contents for the given tag into the value, merging multiple values
1571 * into one if multiple values are associated with the tag.
1573 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1577 * gst_tag_list_get_boolean_index:
1578 * @list: a #GstTagList to get the tag from
1579 * @tag: tag to read out
1580 * @index: number of entry to read out
1581 * @value: (out): location for the result
1583 * Gets the value that is at the given index for the given tag in the given
1586 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1589 TAG_MERGE_FUNCS (boolean, gboolean, TRUE);
1591 * gst_tag_list_get_int:
1592 * @list: a #GstTagList to get the tag from
1593 * @tag: tag to read out
1594 * @value: (out): location for the result
1596 * Copies the contents for the given tag into the value, merging multiple values
1597 * into one if multiple values are associated with the tag.
1599 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1603 * gst_tag_list_get_int_index:
1604 * @list: a #GstTagList to get the tag from
1605 * @tag: tag to read out
1606 * @index: number of entry to read out
1607 * @value: (out): location for the result
1609 * Gets the value that is at the given index for the given tag in the given
1612 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1615 TAG_MERGE_FUNCS (int, gint, TRUE);
1617 * gst_tag_list_get_uint:
1618 * @list: a #GstTagList to get the tag from
1619 * @tag: tag to read out
1620 * @value: (out): location for the result
1622 * Copies the contents for the given tag into the value, merging multiple values
1623 * into one if multiple values are associated with the tag.
1625 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1629 * gst_tag_list_get_uint_index:
1630 * @list: a #GstTagList to get the tag from
1631 * @tag: tag to read out
1632 * @index: number of entry to read out
1633 * @value: (out): location for the result
1635 * Gets the value that is at the given index for the given tag in the given
1638 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1641 TAG_MERGE_FUNCS (uint, guint, TRUE);
1643 * gst_tag_list_get_int64:
1644 * @list: a #GstTagList to get the tag from
1645 * @tag: tag to read out
1646 * @value: (out): location for the result
1648 * Copies the contents for the given tag into the value, merging multiple values
1649 * into one if multiple values are associated with the tag.
1651 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1655 * gst_tag_list_get_int64_index:
1656 * @list: a #GstTagList to get the tag from
1657 * @tag: tag to read out
1658 * @index: number of entry to read out
1659 * @value: (out): location for the result
1661 * Gets the value that is at the given index for the given tag in the given
1664 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1667 TAG_MERGE_FUNCS (int64, gint64, TRUE);
1669 * gst_tag_list_get_uint64:
1670 * @list: a #GstTagList to get the tag from
1671 * @tag: tag to read out
1672 * @value: (out): location for the result
1674 * Copies the contents for the given tag into the value, merging multiple values
1675 * into one if multiple values are associated with the tag.
1677 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1681 * gst_tag_list_get_uint64_index:
1682 * @list: a #GstTagList to get the tag from
1683 * @tag: tag to read out
1684 * @index: number of entry to read out
1685 * @value: (out): location for the result
1687 * Gets the value that is at the given index for the given tag in the given
1690 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1693 TAG_MERGE_FUNCS (uint64, guint64, TRUE);
1695 * gst_tag_list_get_float:
1696 * @list: a #GstTagList to get the tag from
1697 * @tag: tag to read out
1698 * @value: (out): location for the result
1700 * Copies the contents for the given tag into the value, merging multiple values
1701 * into one if multiple values are associated with the tag.
1703 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1707 * gst_tag_list_get_float_index:
1708 * @list: a #GstTagList to get the tag from
1709 * @tag: tag to read out
1710 * @index: number of entry to read out
1711 * @value: (out): location for the result
1713 * Gets the value that is at the given index for the given tag in the given
1716 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1719 TAG_MERGE_FUNCS (float, gfloat, TRUE);
1721 * gst_tag_list_get_double:
1722 * @list: a #GstTagList to get the tag from
1723 * @tag: tag to read out
1724 * @value: (out): location for the result
1726 * Copies the contents for the given tag into the value, merging multiple values
1727 * into one if multiple values are associated with the tag.
1729 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1733 * gst_tag_list_get_double_index:
1734 * @list: a #GstTagList to get the tag from
1735 * @tag: tag to read out
1736 * @index: number of entry to read out
1737 * @value: (out): location for the result
1739 * Gets the value that is at the given index for the given tag in the given
1742 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1745 TAG_MERGE_FUNCS (double, gdouble, TRUE);
1747 * gst_tag_list_get_pointer:
1748 * @list: a #GstTagList to get the tag from
1749 * @tag: tag to read out
1750 * @value: (out) (transfer none): location for the result
1752 * Copies the contents for the given tag into the value, merging multiple values
1753 * into one if multiple values are associated with the tag.
1755 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1759 * gst_tag_list_get_pointer_index:
1760 * @list: a #GstTagList to get the tag from
1761 * @tag: tag to read out
1762 * @index: number of entry to read out
1763 * @value: (out) (transfer none): location for the result
1765 * Gets the value that is at the given index for the given tag in the given
1768 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1771 TAG_MERGE_FUNCS (pointer, gpointer, (*value != NULL));
1773 static inline gchar *
1774 _gst_strdup0 (const gchar * s)
1776 if (s == NULL || *s == '\0')
1779 return g_strdup (s);
1783 #define COPY_FUNC _gst_strdup0
1786 * gst_tag_list_get_string:
1787 * @list: a #GstTagList to get the tag from
1788 * @tag: tag to read out
1789 * @value: (out callee-allocates) (transfer full): location for the result
1791 * Copies the contents for the given tag into the value, possibly merging
1792 * multiple values into one if multiple values are associated with the tag.
1794 * Use gst_tag_list_get_string_index (list, tag, 0, value) if you want
1795 * to retrieve the first string associated with this tag unmodified.
1797 * The resulting string in @value will be in UTF-8 encoding and should be
1798 * freed by the caller using g_free when no longer needed. The
1799 * returned string is also guaranteed to be non-%NULL and non-empty.
1801 * Free-function: g_free
1803 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1807 * gst_tag_list_get_string_index:
1808 * @list: a #GstTagList to get the tag from
1809 * @tag: tag to read out
1810 * @index: number of entry to read out
1811 * @value: (out callee-allocates) (transfer full): location for the result
1813 * Gets the value that is at the given index for the given tag in the given
1816 * The resulting string in @value will be in UTF-8 encoding and should be
1817 * freed by the caller using g_free when no longer needed. The
1818 * returned string is also guaranteed to be non-%NULL and non-empty.
1820 * Free-function: g_free
1822 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1825 TAG_MERGE_FUNCS (string, gchar *, (*value != NULL));
1828 *FIXME 2.0: Instead of _peek (non-copy) and _get (copy), we could have
1829 * _get (non-copy) and _dup (copy) for strings, seems more
1833 * gst_tag_list_peek_string_index:
1834 * @list: a #GstTagList to get the tag from
1835 * @tag: tag to read out
1836 * @index: number of entry to read out
1837 * @value: (out) (transfer none): location for the result
1839 * Peeks at the value that is at the given index for the given tag in the given
1842 * The resulting string in @value will be in UTF-8 encoding and doesn't need
1843 * to be freed by the caller. The returned string is also guaranteed to
1844 * be non-%NULL and non-empty.
1846 * Returns: %TRUE, if a value was set, %FALSE if the tag didn't exist in the
1850 gst_tag_list_peek_string_index (const GstTagList * list,
1851 const gchar * tag, guint index, const gchar ** value)
1855 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1856 g_return_val_if_fail (tag != NULL, FALSE);
1857 g_return_val_if_fail (value != NULL, FALSE);
1859 if ((v = gst_tag_list_get_value_index (list, tag, index)) == NULL)
1861 *value = g_value_get_string (v);
1862 return *value != NULL && **value != '\0';
1866 * gst_tag_list_get_date:
1867 * @list: a #GstTagList to get the tag from
1868 * @tag: tag to read out
1869 * @value: (out callee-allocates) (transfer full): address of a GDate pointer
1870 * variable to store the result into
1872 * Copies the first date for the given tag in the taglist into the variable
1873 * pointed to by @value. Free the date with g_date_free() when it is no longer
1876 * Free-function: g_date_free
1878 * Returns: %TRUE, if a date was copied, %FALSE if the tag didn't exist in the
1879 * given list or if it was %NULL.
1882 gst_tag_list_get_date (const GstTagList * list, const gchar * tag,
1887 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1888 g_return_val_if_fail (tag != NULL, FALSE);
1889 g_return_val_if_fail (value != NULL, FALSE);
1891 if (!gst_tag_list_copy_value (&v, list, tag))
1893 *value = (GDate *) g_value_dup_boxed (&v);
1895 return (*value != NULL);
1899 * gst_tag_list_get_date_index:
1900 * @list: a #GstTagList to get the tag from
1901 * @tag: tag to read out
1902 * @index: number of entry to read out
1903 * @value: (out callee-allocates) (transfer full): location for the result
1905 * Gets the date that is at the given index for the given tag in the given
1906 * list and copies it into the variable pointed to by @value. Free the date
1907 * with g_date_free() when it is no longer needed.
1909 * Free-function: g_date_free
1911 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1912 * given list or if it was %NULL.
1915 gst_tag_list_get_date_index (const GstTagList * list,
1916 const gchar * tag, guint index, GDate ** value)
1920 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1921 g_return_val_if_fail (tag != NULL, FALSE);
1922 g_return_val_if_fail (value != NULL, FALSE);
1924 if ((v = gst_tag_list_get_value_index (list, tag, index)) == NULL)
1926 *value = (GDate *) g_value_dup_boxed (v);
1927 return (*value != NULL);
1931 * gst_tag_list_get_date_time:
1932 * @list: a #GstTagList to get the tag from
1933 * @tag: tag to read out
1934 * @value: (out callee-allocates) (transfer full): address of a #GstDateTime
1935 * pointer variable to store the result into
1937 * Copies the first datetime for the given tag in the taglist into the variable
1938 * pointed to by @value. Unref the date with gst_date_time_unref() when
1939 * it is no longer needed.
1941 * Free-function: gst_date_time_unref
1943 * Returns: %TRUE, if a datetime was copied, %FALSE if the tag didn't exist in
1944 * the given list or if it was %NULL.
1947 gst_tag_list_get_date_time (const GstTagList * list, const gchar * tag,
1948 GstDateTime ** value)
1952 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1953 g_return_val_if_fail (tag != NULL, FALSE);
1954 g_return_val_if_fail (value != NULL, FALSE);
1956 if (!gst_tag_list_copy_value (&v, list, tag))
1959 *value = (GstDateTime *) g_value_dup_boxed (&v);
1961 return (*value != NULL);
1965 * gst_tag_list_get_date_time_index:
1966 * @list: a #GstTagList to get the tag from
1967 * @tag: tag to read out
1968 * @index: number of entry to read out
1969 * @value: (out callee-allocates) (transfer full): location for the result
1971 * Gets the datetime that is at the given index for the given tag in the given
1972 * list and copies it into the variable pointed to by @value. Unref the datetime
1973 * with gst_date_time_unref() when it is no longer needed.
1975 * Free-function: gst_date_time_unref
1977 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1978 * given list or if it was %NULL.
1981 gst_tag_list_get_date_time_index (const GstTagList * list,
1982 const gchar * tag, guint index, GstDateTime ** value)
1986 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1987 g_return_val_if_fail (tag != NULL, FALSE);
1988 g_return_val_if_fail (value != NULL, FALSE);
1990 if ((v = gst_tag_list_get_value_index (list, tag, index)) == NULL)
1992 *value = (GstDateTime *) g_value_dup_boxed (v);
1993 return (*value != NULL);
1997 * gst_tag_list_get_sample:
1998 * @list: a #GstTagList to get the tag from
1999 * @tag: tag to read out
2000 * @sample: (out callee-allocates) (transfer full): address of a GstSample
2001 * pointer variable to store the result into
2003 * Copies the first sample for the given tag in the taglist into the variable
2004 * pointed to by @sample. Free the sample with gst_sample_unref() when it is
2005 * no longer needed. You can retrieve the buffer from the sample using
2006 * gst_sample_get_buffer() and the associated caps (if any) with
2007 * gst_sample_get_caps().
2009 * Free-function: gst_sample_unref
2011 * Returns: %TRUE, if a sample was returned, %FALSE if the tag didn't exist in
2012 * the given list or if it was %NULL.
2015 gst_tag_list_get_sample (const GstTagList * list, const gchar * tag,
2016 GstSample ** sample)
2020 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
2021 g_return_val_if_fail (tag != NULL, FALSE);
2022 g_return_val_if_fail (sample != NULL, FALSE);
2024 if (!gst_tag_list_copy_value (&v, list, tag))
2026 *sample = g_value_dup_boxed (&v);
2028 return (*sample != NULL);
2032 * gst_tag_list_get_sample_index:
2033 * @list: a #GstTagList to get the tag from
2034 * @tag: tag to read out
2035 * @index: number of entry to read out
2036 * @sample: (out callee-allocates) (transfer full): address of a GstSample
2037 * pointer variable to store the result into
2039 * Gets the sample that is at the given index for the given tag in the given
2040 * list and copies it into the variable pointed to by @sample. Free the sample
2041 * with gst_sample_unref() when it is no longer needed. You can retrieve the
2042 * buffer from the sample using gst_sample_get_buffer() and the associated
2043 * caps (if any) with gst_sample_get_caps().
2045 * Free-function: gst_sample_unref
2047 * Returns: %TRUE, if a sample was copied, %FALSE if the tag didn't exist in the
2048 * given list or if it was %NULL.
2051 gst_tag_list_get_sample_index (const GstTagList * list,
2052 const gchar * tag, guint index, GstSample ** sample)
2056 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
2057 g_return_val_if_fail (tag != NULL, FALSE);
2058 g_return_val_if_fail (sample != NULL, FALSE);
2060 if ((v = gst_tag_list_get_value_index (list, tag, index)) == NULL)
2062 *sample = g_value_dup_boxed (v);
2063 return (*sample != NULL);