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: 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);
616 g_return_val_if_fail (info != NULL, NULL);
622 * gst_tag_get_description:
625 * Returns the human-readable description of this tag, You must not change or
628 * Returns: the human-readable description of this tag
631 gst_tag_get_description (const gchar * tag)
635 g_return_val_if_fail (tag != NULL, NULL);
636 info = gst_tag_lookup (tag);
637 g_return_val_if_fail (info != NULL, NULL);
646 * Gets the flag of @tag.
648 * Returns: the flag of this tag.
651 gst_tag_get_flag (const gchar * tag)
655 g_return_val_if_fail (tag != NULL, GST_TAG_FLAG_UNDEFINED);
656 info = gst_tag_lookup (tag);
657 g_return_val_if_fail (info != NULL, GST_TAG_FLAG_UNDEFINED);
666 * Checks if the given tag is fixed. A fixed tag can only contain one value.
667 * Unfixed tags can contain lists of values.
669 * Returns: %TRUE, if the given tag is fixed.
672 gst_tag_is_fixed (const gchar * tag)
676 g_return_val_if_fail (tag != NULL, FALSE);
677 info = gst_tag_lookup (tag);
678 g_return_val_if_fail (info != NULL, FALSE);
680 return info->merge_func == NULL;
683 /* takes ownership of the structure */
685 gst_tag_list_new_internal (GstStructure * s, GstTagScope scope)
687 GstTagList *tag_list;
689 g_assert (s != NULL);
691 tag_list = (GstTagList *) g_slice_new (GstTagListImpl);
693 gst_mini_object_init (GST_MINI_OBJECT_CAST (tag_list), 0, GST_TYPE_TAG_LIST,
694 (GstMiniObjectCopyFunction) __gst_tag_list_copy, NULL,
695 (GstMiniObjectFreeFunction) __gst_tag_list_free);
697 GST_TAG_LIST_STRUCTURE (tag_list) = s;
698 GST_TAG_LIST_SCOPE (tag_list) = scope;
700 #ifdef DEBUG_REFCOUNT
701 GST_CAT_TRACE (GST_CAT_TAGS, "created taglist %p", tag_list);
708 __gst_tag_list_free (GstTagList * list)
710 g_return_if_fail (GST_IS_TAG_LIST (list));
712 #ifdef DEBUG_REFCOUNT
713 GST_CAT_TRACE (GST_CAT_TAGS, "freeing taglist %p", list);
716 gst_structure_free (GST_TAG_LIST_STRUCTURE (list));
718 g_slice_free1 (sizeof (GstTagListImpl), list);
722 __gst_tag_list_copy (const GstTagList * list)
724 const GstStructure *s;
726 g_return_val_if_fail (GST_IS_TAG_LIST (list), NULL);
728 s = GST_TAG_LIST_STRUCTURE (list);
729 return gst_tag_list_new_internal (gst_structure_copy (s),
730 GST_TAG_LIST_SCOPE (list));
734 * gst_tag_list_new_empty:
736 * Creates a new empty GstTagList.
738 * Free-function: gst_tag_list_unref
740 * Returns: (transfer full): An empty tag list
743 gst_tag_list_new_empty (void)
746 GstTagList *tag_list;
748 s = gst_structure_new_id_empty (GST_QUARK (TAGLIST));
749 tag_list = gst_tag_list_new_internal (s, GST_TAG_SCOPE_STREAM);
756 * @...: %NULL-terminated list of values to set
758 * Creates a new taglist and appends the values for the given tags. It expects
759 * tag-value pairs like gst_tag_list_add(), and a %NULL terminator after the
760 * last pair. The type of the values is implicit and is documented in the API
761 * reference, but can also be queried at runtime with gst_tag_get_type(). It
762 * is an error to pass a value of a type not matching the tag type into this
763 * function. The tag list will make copies of any arguments passed
764 * (e.g. strings, buffers).
766 * After creation you might also want to set a #GstTagScope on the returned
767 * taglist to signal if the contained tags are global or stream tags. By
768 * default stream scope is assumes. See gst_tag_list_set_scope().
770 * Free-function: gst_tag_list_unref
772 * Returns: (transfer full): a new #GstTagList. Free with gst_tag_list_unref()
773 * when no longer needed.
776 gst_tag_list_new (const gchar * tag, ...)
781 g_return_val_if_fail (tag != NULL, NULL);
783 list = gst_tag_list_new_empty ();
784 va_start (args, tag);
785 gst_tag_list_add_valist (list, GST_TAG_MERGE_APPEND, tag, args);
792 * gst_tag_list_new_valist:
793 * @var_args: tag / value pairs to set
795 * Just like gst_tag_list_new(), only that it takes a va_list argument.
796 * Useful mostly for language bindings.
798 * Free-function: gst_tag_list_unref
800 * Returns: (transfer full): a new #GstTagList. Free with gst_tag_list_unref()
801 * when no longer needed.
804 gst_tag_list_new_valist (va_list var_args)
809 list = gst_tag_list_new_empty ();
811 tag = va_arg (var_args, gchar *);
812 gst_tag_list_add_valist (list, GST_TAG_MERGE_APPEND, tag, var_args);
818 * gst_tag_list_set_scope:
819 * @list: a #GstTagList
820 * @scope: new scope for @list
822 * Sets the scope of @list to @scope. By default the scope
823 * of a taglist is stream scope.
827 gst_tag_list_set_scope (GstTagList * list, GstTagScope scope)
829 g_return_if_fail (GST_IS_TAG_LIST (list));
830 g_return_if_fail (gst_tag_list_is_writable (list));
832 GST_TAG_LIST_SCOPE (list) = scope;
836 * gst_tag_list_get_scope:
837 * @list: a #GstTagList
839 * Gets the scope of @list.
841 * Returns: The scope of @list
844 gst_tag_list_get_scope (const GstTagList * list)
846 g_return_val_if_fail (GST_IS_TAG_LIST (list), GST_TAG_SCOPE_STREAM);
848 return GST_TAG_LIST_SCOPE (list);
852 * gst_tag_list_to_string:
853 * @list: a #GstTagList
855 * Serializes a tag list to a string.
857 * Returns: (nullable): a newly-allocated string, or %NULL in case of
858 * an error. The string must be freed with g_free() when no longer
862 gst_tag_list_to_string (const GstTagList * list)
864 g_return_val_if_fail (GST_IS_TAG_LIST (list), NULL);
866 return gst_structure_to_string (GST_TAG_LIST_STRUCTURE (list));
870 * gst_tag_list_new_from_string:
871 * @str: a string created with gst_tag_list_to_string()
873 * Deserializes a tag list.
875 * Returns: (nullable): a new #GstTagList, or %NULL in case of an
879 gst_tag_list_new_from_string (const gchar * str)
881 GstTagList *tag_list;
884 g_return_val_if_fail (str != NULL, NULL);
885 g_return_val_if_fail (g_str_has_prefix (str, "taglist"), NULL);
887 s = gst_structure_from_string (str, NULL);
891 tag_list = gst_tag_list_new_internal (s, GST_TAG_SCOPE_STREAM);
897 * gst_tag_list_n_tags:
898 * @list: A #GstTagList.
900 * Get the number of tags in @list.
902 * Returns: The number of tags in @list.
905 gst_tag_list_n_tags (const GstTagList * list)
907 g_return_val_if_fail (list != NULL, 0);
908 g_return_val_if_fail (GST_IS_TAG_LIST (list), 0);
910 return gst_structure_n_fields (GST_TAG_LIST_STRUCTURE (list));
914 * gst_tag_list_nth_tag_name:
915 * @list: A #GstTagList.
918 * Get the name of the tag in @list at @index.
920 * Returns: The name of the tag at @index.
923 gst_tag_list_nth_tag_name (const GstTagList * list, guint index)
925 g_return_val_if_fail (list != NULL, 0);
926 g_return_val_if_fail (GST_IS_TAG_LIST (list), 0);
928 return gst_structure_nth_field_name (GST_TAG_LIST_STRUCTURE (list), index);
932 * gst_tag_list_is_empty:
933 * @list: A #GstTagList.
935 * Checks if the given taglist is empty.
937 * Returns: %TRUE if the taglist is empty, otherwise %FALSE.
940 gst_tag_list_is_empty (const GstTagList * list)
942 g_return_val_if_fail (list != NULL, FALSE);
943 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
945 return (gst_structure_n_fields (GST_TAG_LIST_STRUCTURE (list)) == 0);
949 gst_tag_list_fields_equal (const GValue * value1, const GValue * value2)
953 if (gst_value_compare (value1, value2) == GST_VALUE_EQUAL)
956 /* fields not equal: add some tolerance for doubles, otherwise bail out */
957 if (!G_VALUE_HOLDS_DOUBLE (value1) || !G_VALUE_HOLDS_DOUBLE (value2))
960 d1 = g_value_get_double (value1);
961 d2 = g_value_get_double (value2);
963 /* This will only work for 'normal' values and values around 0,
964 * which should be good enough for our purposes here
965 * FIXME: maybe add this to gst_value_compare_double() ? */
966 return (fabs (d1 - d2) < 0.0000001);
970 * gst_tag_list_is_equal:
971 * @list1: a #GstTagList.
972 * @list2: a #GstTagList.
974 * Checks if the two given taglists are equal.
976 * Returns: %TRUE if the taglists are equal, otherwise %FALSE
979 gst_tag_list_is_equal (const GstTagList * list1, const GstTagList * list2)
981 const GstStructure *s1, *s2;
982 gint num_fields1, num_fields2, i;
984 g_return_val_if_fail (GST_IS_TAG_LIST (list1), FALSE);
985 g_return_val_if_fail (GST_IS_TAG_LIST (list2), FALSE);
987 /* we don't just use gst_structure_is_equal() here so we can add some
988 * tolerance for doubles, though maybe we should just add that to
989 * gst_value_compare_double() as well? */
990 s1 = GST_TAG_LIST_STRUCTURE (list1);
991 s2 = GST_TAG_LIST_STRUCTURE (list2);
993 num_fields1 = gst_structure_n_fields (s1);
994 num_fields2 = gst_structure_n_fields (s2);
996 if (num_fields1 != num_fields2)
999 for (i = 0; i < num_fields1; i++) {
1000 const GValue *value1, *value2;
1001 const gchar *tag_name;
1003 tag_name = gst_structure_nth_field_name (s1, i);
1004 value1 = gst_structure_get_value (s1, tag_name);
1005 value2 = gst_structure_get_value (s2, tag_name);
1010 if (!gst_tag_list_fields_equal (value1, value2))
1020 GstTagMergeMode mode;
1025 gst_tag_list_add_value_internal (GstTagList * tag_list, GstTagMergeMode mode,
1026 const gchar * tag, const GValue * value, GstTagInfo * info)
1028 GstStructure *list = GST_TAG_LIST_STRUCTURE (tag_list);
1029 const GValue *value2;
1033 info = gst_tag_lookup (tag);
1034 if (G_UNLIKELY (info == NULL)) {
1035 g_warning ("unknown tag '%s'", tag);
1040 if (G_UNLIKELY (!G_VALUE_HOLDS (value, info->type) &&
1041 !GST_VALUE_HOLDS_LIST (value))) {
1042 g_warning ("tag '%s' should hold value of type '%s', but value of "
1043 "type '%s' passed", info->nick, g_type_name (info->type),
1044 g_type_name (G_VALUE_TYPE (value)));
1048 tag_quark = info->name_quark;
1050 if (info->merge_func
1051 && (value2 = gst_structure_id_get_value (list, tag_quark)) != NULL) {
1052 GValue dest = { 0, };
1055 case GST_TAG_MERGE_REPLACE_ALL:
1056 case GST_TAG_MERGE_REPLACE:
1057 gst_structure_id_set_value (list, tag_quark, value);
1059 case GST_TAG_MERGE_PREPEND:
1060 if (GST_VALUE_HOLDS_LIST (value2) && !GST_VALUE_HOLDS_LIST (value))
1061 gst_value_list_prepend_value ((GValue *) value2, value);
1063 gst_value_list_merge (&dest, value, value2);
1064 gst_structure_id_take_value (list, tag_quark, &dest);
1067 case GST_TAG_MERGE_APPEND:
1068 if (GST_VALUE_HOLDS_LIST (value2) && !GST_VALUE_HOLDS_LIST (value))
1069 gst_value_list_append_value ((GValue *) value2, value);
1071 gst_value_list_merge (&dest, value2, value);
1072 gst_structure_id_take_value (list, tag_quark, &dest);
1075 case GST_TAG_MERGE_KEEP:
1076 case GST_TAG_MERGE_KEEP_ALL:
1079 g_assert_not_reached ();
1084 case GST_TAG_MERGE_APPEND:
1085 case GST_TAG_MERGE_KEEP:
1086 if (gst_structure_id_get_value (list, tag_quark) != NULL)
1089 case GST_TAG_MERGE_REPLACE_ALL:
1090 case GST_TAG_MERGE_REPLACE:
1091 case GST_TAG_MERGE_PREPEND:
1092 gst_structure_id_set_value (list, tag_quark, value);
1094 case GST_TAG_MERGE_KEEP_ALL:
1097 g_assert_not_reached ();
1104 gst_tag_list_copy_foreach (GQuark tag_quark, const GValue * value,
1107 GstTagCopyData *copy = (GstTagCopyData *) user_data;
1110 tag = g_quark_to_string (tag_quark);
1111 gst_tag_list_add_value_internal (copy->list, copy->mode, tag, value, NULL);
1117 * gst_tag_list_insert:
1118 * @into: list to merge into
1119 * @from: list to merge from
1120 * @mode: the mode to use
1122 * Inserts the tags of the @from list into the first list using the given mode.
1125 gst_tag_list_insert (GstTagList * into, const GstTagList * from,
1126 GstTagMergeMode mode)
1128 GstTagCopyData data;
1130 g_return_if_fail (GST_IS_TAG_LIST (into));
1131 g_return_if_fail (gst_tag_list_is_writable (into));
1132 g_return_if_fail (GST_IS_TAG_LIST (from));
1133 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1137 if (mode == GST_TAG_MERGE_REPLACE_ALL) {
1138 gst_structure_remove_all_fields (GST_TAG_LIST_STRUCTURE (into));
1140 gst_structure_foreach (GST_TAG_LIST_STRUCTURE (from),
1141 gst_tag_list_copy_foreach, &data);
1145 * gst_tag_list_merge:
1146 * @list1: (allow-none): first list to merge
1147 * @list2: (allow-none): second list to merge
1148 * @mode: the mode to use
1150 * Merges the two given lists into a new list. If one of the lists is %NULL, a
1151 * copy of the other is returned. If both lists are %NULL, %NULL is returned.
1153 * Free-function: gst_tag_list_unref
1155 * Returns: (transfer full) (nullable): the new list
1158 gst_tag_list_merge (const GstTagList * list1, const GstTagList * list2,
1159 GstTagMergeMode mode)
1161 GstTagList *list1_cp;
1162 const GstTagList *list2_cp;
1164 g_return_val_if_fail (list1 == NULL || GST_IS_TAG_LIST (list1), NULL);
1165 g_return_val_if_fail (list2 == NULL || GST_IS_TAG_LIST (list2), NULL);
1166 g_return_val_if_fail (GST_TAG_MODE_IS_VALID (mode), NULL);
1168 /* nothing to merge */
1169 if (!list1 && !list2) {
1173 /* create empty list, we need to do this to correctly handling merge modes */
1174 list1_cp = (list1) ? gst_tag_list_copy (list1) : gst_tag_list_new_empty ();
1175 list2_cp = (list2) ? list2 : gst_tag_list_new_empty ();
1177 gst_tag_list_insert (list1_cp, list2_cp, mode);
1180 gst_tag_list_unref ((GstTagList *) list2_cp);
1186 * gst_tag_list_get_tag_size:
1188 * @tag: the tag to query
1190 * Checks how many value are stored in this tag list for the given tag.
1192 * Returns: The number of tags stored
1195 gst_tag_list_get_tag_size (const GstTagList * list, const gchar * tag)
1197 const GValue *value;
1199 g_return_val_if_fail (GST_IS_TAG_LIST (list), 0);
1201 value = gst_structure_get_value (GST_TAG_LIST_STRUCTURE (list), tag);
1204 if (G_VALUE_TYPE (value) != GST_TYPE_LIST)
1207 return gst_value_list_get_size (value);
1212 * @list: list to set tags in
1213 * @mode: the mode to use
1215 * @...: %NULL-terminated list of values to set
1217 * Sets the values for the given tags using the specified mode.
1220 gst_tag_list_add (GstTagList * list, GstTagMergeMode mode, const gchar * tag,
1225 g_return_if_fail (GST_IS_TAG_LIST (list));
1226 g_return_if_fail (gst_tag_list_is_writable (list));
1227 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1228 g_return_if_fail (tag != NULL);
1230 va_start (args, tag);
1231 gst_tag_list_add_valist (list, mode, tag, args);
1236 * gst_tag_list_add_values:
1237 * @list: list to set tags in
1238 * @mode: the mode to use
1240 * @...: GValues to set
1242 * Sets the GValues for the given tags using the specified mode.
1245 gst_tag_list_add_values (GstTagList * list, GstTagMergeMode mode,
1246 const gchar * tag, ...)
1250 g_return_if_fail (GST_IS_TAG_LIST (list));
1251 g_return_if_fail (gst_tag_list_is_writable (list));
1252 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1253 g_return_if_fail (tag != NULL);
1255 va_start (args, tag);
1256 gst_tag_list_add_valist_values (list, mode, tag, args);
1261 * gst_tag_list_add_valist:
1262 * @list: list to set tags in
1263 * @mode: the mode to use
1265 * @var_args: tag / value pairs to set
1267 * Sets the values for the given tags using the specified mode.
1270 gst_tag_list_add_valist (GstTagList * list, GstTagMergeMode mode,
1271 const gchar * tag, va_list var_args)
1274 gchar *error = NULL;
1276 g_return_if_fail (GST_IS_TAG_LIST (list));
1277 g_return_if_fail (gst_tag_list_is_writable (list));
1278 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1279 g_return_if_fail (tag != NULL);
1281 if (mode == GST_TAG_MERGE_REPLACE_ALL) {
1282 gst_structure_remove_all_fields (GST_TAG_LIST_STRUCTURE (list));
1285 while (tag != NULL) {
1286 GValue value = { 0, };
1288 info = gst_tag_lookup (tag);
1289 if (G_UNLIKELY (info == NULL)) {
1290 g_warning ("unknown tag '%s'", tag);
1293 G_VALUE_COLLECT_INIT (&value, info->type, var_args, 0, &error);
1295 g_warning ("%s: %s", G_STRLOC, error);
1297 /* we purposely leak the value here, it might not be
1298 * in a sane state if an error condition occoured
1302 /* Facilitate GstBuffer -> GstSample transition */
1303 if (G_UNLIKELY (info->type == GST_TYPE_SAMPLE &&
1304 !GST_IS_SAMPLE (value.data[0].v_pointer))) {
1305 g_warning ("Expected GstSample argument for tag '%s'", tag);
1307 gst_tag_list_add_value_internal (list, mode, tag, &value, info);
1309 g_value_unset (&value);
1310 tag = va_arg (var_args, gchar *);
1315 * gst_tag_list_add_valist_values:
1316 * @list: list to set tags in
1317 * @mode: the mode to use
1319 * @var_args: tag / GValue pairs to set
1321 * Sets the GValues for the given tags using the specified mode.
1324 gst_tag_list_add_valist_values (GstTagList * list, GstTagMergeMode mode,
1325 const gchar * tag, va_list var_args)
1327 g_return_if_fail (GST_IS_TAG_LIST (list));
1328 g_return_if_fail (gst_tag_list_is_writable (list));
1329 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1330 g_return_if_fail (tag != NULL);
1332 if (mode == GST_TAG_MERGE_REPLACE_ALL) {
1333 gst_structure_remove_all_fields (GST_TAG_LIST_STRUCTURE (list));
1336 while (tag != NULL) {
1339 info = gst_tag_lookup (tag);
1340 if (G_UNLIKELY (info == NULL)) {
1341 g_warning ("unknown tag '%s'", tag);
1344 gst_tag_list_add_value_internal (list, mode, tag, va_arg (var_args,
1346 tag = va_arg (var_args, gchar *);
1351 * gst_tag_list_add_value:
1352 * @list: list to set tags in
1353 * @mode: the mode to use
1355 * @value: GValue for this tag
1357 * Sets the GValue for a given tag using the specified mode.
1360 gst_tag_list_add_value (GstTagList * list, GstTagMergeMode mode,
1361 const gchar * tag, const GValue * value)
1363 g_return_if_fail (GST_IS_TAG_LIST (list));
1364 g_return_if_fail (gst_tag_list_is_writable (list));
1365 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
1366 g_return_if_fail (tag != NULL);
1368 gst_tag_list_add_value_internal (list, mode, tag, value, NULL);
1372 * gst_tag_list_remove_tag:
1373 * @list: list to remove tag from
1374 * @tag: tag to remove
1376 * Removes the given tag from the taglist.
1379 gst_tag_list_remove_tag (GstTagList * list, const gchar * tag)
1381 g_return_if_fail (GST_IS_TAG_LIST (list));
1382 g_return_if_fail (gst_tag_list_is_writable (list));
1383 g_return_if_fail (tag != NULL);
1385 gst_structure_remove_field (GST_TAG_LIST_STRUCTURE (list), tag);
1390 GstTagForeachFunc func;
1391 const GstTagList *tag_list;
1397 structure_foreach_wrapper (GQuark field_id, const GValue * value,
1400 TagForeachData *data = (TagForeachData *) user_data;
1402 data->func (data->tag_list, g_quark_to_string (field_id), data->data);
1407 * gst_tag_list_foreach:
1408 * @list: list to iterate over
1409 * @func: (scope call): function to be called for each tag
1410 * @user_data: (closure): user specified data
1412 * Calls the given function for each tag inside the tag list. Note that if there
1413 * is no tag, the function won't be called at all.
1416 gst_tag_list_foreach (const GstTagList * list, GstTagForeachFunc func,
1419 TagForeachData data;
1421 g_return_if_fail (GST_IS_TAG_LIST (list));
1422 g_return_if_fail (func != NULL);
1425 data.tag_list = list;
1426 data.data = user_data;
1427 gst_structure_foreach (GST_TAG_LIST_STRUCTURE (list),
1428 structure_foreach_wrapper, &data);
1432 * gst_tag_list_get_value_index:
1433 * @list: a #GstTagList
1434 * @tag: tag to read out
1435 * @index: number of entry to read out
1437 * Gets the value that is at the given index for the given tag in the given
1440 * Returns: (transfer none) (nullable): The GValue for the specified
1441 * entry or %NULL if the tag wasn't available or the tag
1442 * doesn't have as many entries
1445 gst_tag_list_get_value_index (const GstTagList * list, const gchar * tag,
1448 const GValue *value;
1450 g_return_val_if_fail (GST_IS_TAG_LIST (list), NULL);
1451 g_return_val_if_fail (tag != NULL, NULL);
1453 value = gst_structure_get_value (GST_TAG_LIST_STRUCTURE (list), tag);
1457 if (GST_VALUE_HOLDS_LIST (value)) {
1458 if (index >= gst_value_list_get_size (value))
1460 return gst_value_list_get_value (value, index);
1469 * gst_tag_list_copy_value:
1470 * @dest: (out caller-allocates): uninitialized #GValue to copy into
1471 * @list: list to get the tag from
1472 * @tag: tag to read out
1474 * Copies the contents for the given tag into the value,
1475 * merging multiple values into one if multiple values are associated
1477 * You must g_value_unset() the value after use.
1479 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1483 gst_tag_list_copy_value (GValue * dest, const GstTagList * list,
1488 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1489 g_return_val_if_fail (tag != NULL, FALSE);
1490 g_return_val_if_fail (dest != NULL, FALSE);
1491 g_return_val_if_fail (G_VALUE_TYPE (dest) == 0, FALSE);
1493 src = gst_structure_get_value (GST_TAG_LIST_STRUCTURE (list), tag);
1497 if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
1498 GstTagInfo *info = gst_tag_lookup (tag);
1503 /* must be there or lists aren't allowed */
1504 g_assert (info->merge_func);
1505 info->merge_func (dest, src);
1507 g_value_init (dest, G_VALUE_TYPE (src));
1508 g_value_copy (src, dest);
1513 /* FIXME 2.0: this whole merge function business is overdesigned, and the
1514 * _get_foo() API is misleading as well - how many application developers will
1515 * expect gst_tag_list_get_string (list, GST_TAG_ARTIST, &val) might return a
1516 * string with multiple comma-separated artists? _get_foo() should just be
1517 * a convenience wrapper around _get_foo_index (list, tag, 0, &val),
1518 * supplemented by a special _tag_list_get_string_merged() function if needed
1519 * (unless someone can actually think of real use cases where the merge
1520 * function is not 'use first' for non-strings and merge for strings) */
1522 /***** evil macros to get all the gst_tag_list_get_*() functions right *****/
1524 #define TAG_MERGE_FUNCS(name,type,ret) \
1526 gst_tag_list_get_ ## name (const GstTagList *list, const gchar *tag, \
1529 GValue v = { 0, }; \
1531 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE); \
1532 g_return_val_if_fail (tag != NULL, FALSE); \
1533 g_return_val_if_fail (value != NULL, FALSE); \
1535 if (!gst_tag_list_copy_value (&v, list, tag)) \
1537 *value = COPY_FUNC (g_value_get_ ## name (&v)); \
1538 g_value_unset (&v); \
1543 gst_tag_list_get_ ## name ## _index (const GstTagList *list, \
1545 guint index, type *value) \
1549 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE); \
1550 g_return_val_if_fail (tag != NULL, FALSE); \
1551 g_return_val_if_fail (value != NULL, FALSE); \
1553 if ((v = gst_tag_list_get_value_index (list, tag, index)) == NULL) \
1555 *value = COPY_FUNC (g_value_get_ ## name (v)); \
1559 #define COPY_FUNC /**/
1561 * gst_tag_list_get_boolean:
1562 * @list: a #GstTagList to get the tag from
1563 * @tag: tag to read out
1564 * @value: (out): location for the result
1566 * Copies the contents for the given tag into the value, merging multiple values
1567 * into one if multiple values are associated with the tag.
1569 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1573 * gst_tag_list_get_boolean_index:
1574 * @list: a #GstTagList to get the tag from
1575 * @tag: tag to read out
1576 * @index: number of entry to read out
1577 * @value: (out): location for the result
1579 * Gets the value that is at the given index for the given tag in the given
1582 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1585 TAG_MERGE_FUNCS (boolean, gboolean, TRUE);
1587 * gst_tag_list_get_int:
1588 * @list: a #GstTagList to get the tag from
1589 * @tag: tag to read out
1590 * @value: (out): location for the result
1592 * Copies the contents for the given tag into the value, merging multiple values
1593 * into one if multiple values are associated with the tag.
1595 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1599 * gst_tag_list_get_int_index:
1600 * @list: a #GstTagList to get the tag from
1601 * @tag: tag to read out
1602 * @index: number of entry to read out
1603 * @value: (out): location for the result
1605 * Gets the value that is at the given index for the given tag in the given
1608 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1611 TAG_MERGE_FUNCS (int, gint, TRUE);
1613 * gst_tag_list_get_uint:
1614 * @list: a #GstTagList to get the tag from
1615 * @tag: tag to read out
1616 * @value: (out): location for the result
1618 * Copies the contents for the given tag into the value, merging multiple values
1619 * into one if multiple values are associated with the tag.
1621 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1625 * gst_tag_list_get_uint_index:
1626 * @list: a #GstTagList to get the tag from
1627 * @tag: tag to read out
1628 * @index: number of entry to read out
1629 * @value: (out): location for the result
1631 * Gets the value that is at the given index for the given tag in the given
1634 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1637 TAG_MERGE_FUNCS (uint, guint, TRUE);
1639 * gst_tag_list_get_int64_index:
1640 * @list: a #GstTagList to get the tag from
1641 * @tag: tag to read out
1642 * @index: number of entry to read out
1643 * @value: (out): location for the result
1645 * Gets the value that is at the given index for the given tag in the given
1648 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1651 TAG_MERGE_FUNCS (int64, gint64, TRUE);
1653 * gst_tag_list_get_uint64:
1654 * @list: a #GstTagList to get the tag from
1655 * @tag: tag to read out
1656 * @value: (out): location for the result
1658 * Copies the contents for the given tag into the value, merging multiple values
1659 * into one if multiple values are associated with the tag.
1661 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1665 * gst_tag_list_get_uint64_index:
1666 * @list: a #GstTagList to get the tag from
1667 * @tag: tag to read out
1668 * @index: number of entry to read out
1669 * @value: (out): location for the result
1671 * Gets the value that is at the given index for the given tag in the given
1674 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1677 TAG_MERGE_FUNCS (uint64, guint64, TRUE);
1679 * gst_tag_list_get_float:
1680 * @list: a #GstTagList to get the tag from
1681 * @tag: tag to read out
1682 * @value: (out): location for the result
1684 * Copies the contents for the given tag into the value, merging multiple values
1685 * into one if multiple values are associated with the tag.
1687 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1691 * gst_tag_list_get_float_index:
1692 * @list: a #GstTagList to get the tag from
1693 * @tag: tag to read out
1694 * @index: number of entry to read out
1695 * @value: (out): location for the result
1697 * Gets the value that is at the given index for the given tag in the given
1700 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1703 TAG_MERGE_FUNCS (float, gfloat, TRUE);
1705 * gst_tag_list_get_double:
1706 * @list: a #GstTagList to get the tag from
1707 * @tag: tag to read out
1708 * @value: (out): location for the result
1710 * Copies the contents for the given tag into the value, merging multiple values
1711 * into one if multiple values are associated with the tag.
1713 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1717 * gst_tag_list_get_double_index:
1718 * @list: a #GstTagList to get the tag from
1719 * @tag: tag to read out
1720 * @index: number of entry to read out
1721 * @value: (out): location for the result
1723 * Gets the value that is at the given index for the given tag in the given
1726 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1729 TAG_MERGE_FUNCS (double, gdouble, TRUE);
1731 * gst_tag_list_get_pointer:
1732 * @list: a #GstTagList to get the tag from
1733 * @tag: tag to read out
1734 * @value: (out) (transfer none): location for the result
1736 * Copies the contents for the given tag into the value, merging multiple values
1737 * into one if multiple values are associated with the tag.
1739 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1743 * gst_tag_list_get_pointer_index:
1744 * @list: a #GstTagList to get the tag from
1745 * @tag: tag to read out
1746 * @index: number of entry to read out
1747 * @value: (out) (transfer none): location for the result
1749 * Gets the value that is at the given index for the given tag in the given
1752 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1755 TAG_MERGE_FUNCS (pointer, gpointer, (*value != NULL));
1757 static inline gchar *
1758 _gst_strdup0 (const gchar * s)
1760 if (s == NULL || *s == '\0')
1763 return g_strdup (s);
1767 #define COPY_FUNC _gst_strdup0
1770 * gst_tag_list_get_string:
1771 * @list: a #GstTagList to get the tag from
1772 * @tag: tag to read out
1773 * @value: (out callee-allocates) (transfer full): location for the result
1775 * Copies the contents for the given tag into the value, possibly merging
1776 * multiple values into one if multiple values are associated with the tag.
1778 * Use gst_tag_list_get_string_index (list, tag, 0, value) if you want
1779 * to retrieve the first string associated with this tag unmodified.
1781 * The resulting string in @value will be in UTF-8 encoding and should be
1782 * freed by the caller using g_free when no longer needed. The
1783 * returned string is also guaranteed to be non-%NULL and non-empty.
1785 * Free-function: g_free
1787 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1791 * gst_tag_list_get_string_index:
1792 * @list: a #GstTagList to get the tag from
1793 * @tag: tag to read out
1794 * @index: number of entry to read out
1795 * @value: (out callee-allocates) (transfer full): location for the result
1797 * Gets the value that is at the given index for the given tag in the given
1800 * The resulting string in @value will be in UTF-8 encoding and should be
1801 * freed by the caller using g_free when no longer needed. The
1802 * returned string is also guaranteed to be non-%NULL and non-empty.
1804 * Free-function: g_free
1806 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1809 TAG_MERGE_FUNCS (string, gchar *, (*value != NULL));
1812 *FIXME 2.0: Instead of _peek (non-copy) and _get (copy), we could have
1813 * _get (non-copy) and _dup (copy) for strings, seems more
1817 * gst_tag_list_peek_string_index:
1818 * @list: a #GstTagList to get the tag from
1819 * @tag: tag to read out
1820 * @index: number of entry to read out
1821 * @value: (out) (transfer none): location for the result
1823 * Peeks at the value that is at the given index for the given tag in the given
1826 * The resulting string in @value will be in UTF-8 encoding and doesn't need
1827 * to be freed by the caller. The returned string is also guaranteed to
1828 * be non-%NULL and non-empty.
1830 * Returns: %TRUE, if a value was set, %FALSE if the tag didn't exist in the
1834 gst_tag_list_peek_string_index (const GstTagList * list,
1835 const gchar * tag, guint index, const gchar ** value)
1839 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1840 g_return_val_if_fail (tag != NULL, FALSE);
1841 g_return_val_if_fail (value != NULL, FALSE);
1843 if ((v = gst_tag_list_get_value_index (list, tag, index)) == NULL)
1845 *value = g_value_get_string (v);
1846 return *value != NULL && **value != '\0';
1850 * gst_tag_list_get_date:
1851 * @list: a #GstTagList to get the tag from
1852 * @tag: tag to read out
1853 * @value: (out callee-allocates) (transfer full): address of a GDate pointer
1854 * variable to store the result into
1856 * Copies the first date for the given tag in the taglist into the variable
1857 * pointed to by @value. Free the date with g_date_free() when it is no longer
1860 * Free-function: g_date_free
1862 * Returns: %TRUE, if a date was copied, %FALSE if the tag didn't exist in the
1863 * given list or if it was %NULL.
1866 gst_tag_list_get_date (const GstTagList * list, const gchar * tag,
1871 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1872 g_return_val_if_fail (tag != NULL, FALSE);
1873 g_return_val_if_fail (value != NULL, FALSE);
1875 if (!gst_tag_list_copy_value (&v, list, tag))
1877 *value = (GDate *) g_value_dup_boxed (&v);
1879 return (*value != NULL);
1883 * gst_tag_list_get_date_index:
1884 * @list: a #GstTagList to get the tag from
1885 * @tag: tag to read out
1886 * @index: number of entry to read out
1887 * @value: (out callee-allocates) (transfer full): location for the result
1889 * Gets the date that is at the given index for the given tag in the given
1890 * list and copies it into the variable pointed to by @value. Free the date
1891 * with g_date_free() when it is no longer needed.
1893 * Free-function: g_date_free
1895 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1896 * given list or if it was %NULL.
1899 gst_tag_list_get_date_index (const GstTagList * list,
1900 const gchar * tag, guint index, GDate ** value)
1904 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1905 g_return_val_if_fail (tag != NULL, FALSE);
1906 g_return_val_if_fail (value != NULL, FALSE);
1908 if ((v = gst_tag_list_get_value_index (list, tag, index)) == NULL)
1910 *value = (GDate *) g_value_dup_boxed (v);
1911 return (*value != NULL);
1915 * gst_tag_list_get_date_time:
1916 * @list: a #GstTagList to get the tag from
1917 * @tag: tag to read out
1918 * @value: (out callee-allocates) (transfer full): address of a #GstDateTime
1919 * pointer variable to store the result into
1921 * Copies the first datetime for the given tag in the taglist into the variable
1922 * pointed to by @value. Unref the date with gst_date_time_unref() when
1923 * it is no longer needed.
1925 * Free-function: gst_date_time_unref
1927 * Returns: %TRUE, if a datetime was copied, %FALSE if the tag didn't exist in
1928 * the given list or if it was %NULL.
1931 gst_tag_list_get_date_time (const GstTagList * list, const gchar * tag,
1932 GstDateTime ** value)
1936 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1937 g_return_val_if_fail (tag != NULL, FALSE);
1938 g_return_val_if_fail (value != NULL, FALSE);
1940 if (!gst_tag_list_copy_value (&v, list, tag))
1943 *value = (GstDateTime *) g_value_dup_boxed (&v);
1945 return (*value != NULL);
1949 * gst_tag_list_get_date_time_index:
1950 * @list: a #GstTagList to get the tag from
1951 * @tag: tag to read out
1952 * @index: number of entry to read out
1953 * @value: (out callee-allocates) (transfer full): location for the result
1955 * Gets the datetime that is at the given index for the given tag in the given
1956 * list and copies it into the variable pointed to by @value. Unref the datetime
1957 * with gst_date_time_unref() when it is no longer needed.
1959 * Free-function: gst_date_time_unref
1961 * Returns: %TRUE, if a value was copied, %FALSE if the tag didn't exist in the
1962 * given list or if it was %NULL.
1965 gst_tag_list_get_date_time_index (const GstTagList * list,
1966 const gchar * tag, guint index, GstDateTime ** value)
1970 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
1971 g_return_val_if_fail (tag != NULL, FALSE);
1972 g_return_val_if_fail (value != NULL, FALSE);
1974 if ((v = gst_tag_list_get_value_index (list, tag, index)) == NULL)
1976 *value = (GstDateTime *) g_value_dup_boxed (v);
1977 return (*value != NULL);
1981 * gst_tag_list_get_sample:
1982 * @list: a #GstTagList to get the tag from
1983 * @tag: tag to read out
1984 * @sample: (out callee-allocates) (transfer full): address of a GstSample
1985 * pointer variable to store the result into
1987 * Copies the first sample for the given tag in the taglist into the variable
1988 * pointed to by @sample. Free the sample with gst_sample_unref() when it is
1989 * no longer needed. You can retrieve the buffer from the sample using
1990 * gst_sample_get_buffer() and the associated caps (if any) with
1991 * gst_sample_get_caps().
1993 * Free-function: gst_sample_unref
1995 * Returns: %TRUE, if a sample was returned, %FALSE if the tag didn't exist in
1996 * the given list or if it was %NULL.
1999 gst_tag_list_get_sample (const GstTagList * list, const gchar * tag,
2000 GstSample ** sample)
2004 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
2005 g_return_val_if_fail (tag != NULL, FALSE);
2006 g_return_val_if_fail (sample != NULL, FALSE);
2008 if (!gst_tag_list_copy_value (&v, list, tag))
2010 *sample = g_value_dup_boxed (&v);
2012 return (*sample != NULL);
2016 * gst_tag_list_get_sample_index:
2017 * @list: a #GstTagList to get the tag from
2018 * @tag: tag to read out
2019 * @index: number of entry to read out
2020 * @sample: (out callee-allocates) (transfer full): address of a GstSample
2021 * pointer variable to store the result into
2023 * Gets the sample that is at the given index for the given tag in the given
2024 * list and copies it into the variable pointed to by @sample. Free the sample
2025 * with gst_sample_unref() when it is no longer needed. You can retrieve the
2026 * buffer from the sample using gst_sample_get_buffer() and the associated
2027 * caps (if any) with gst_sample_get_caps().
2029 * Free-function: gst_sample_unref
2031 * Returns: %TRUE, if a sample was copied, %FALSE if the tag didn't exist in the
2032 * given list or if it was %NULL.
2035 gst_tag_list_get_sample_index (const GstTagList * list,
2036 const gchar * tag, guint index, GstSample ** sample)
2040 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
2041 g_return_val_if_fail (tag != NULL, FALSE);
2042 g_return_val_if_fail (sample != NULL, FALSE);
2044 if ((v = gst_tag_list_get_value_index (list, tag, index)) == NULL)
2046 *sample = g_value_dup_boxed (v);
2047 return (*sample != NULL);