2 * Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
4 * gsttag.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., 59 Temple Place - Suite 330,
19 * Boston, MA 02111-1307, USA.
26 #include "gst_private.h"
27 #include "gst-i18n-lib.h"
32 #include <gobject/gvaluecollector.h>
35 #define GST_TAG_IS_VALID(tag) (gst_tag_get_info (tag) != NULL)
38 GType type; /* type the data is in */
40 gchar * nick; /* translated name */
41 gchar * blurb; /* translated description of type */
43 GstTagMergeFunc merge_func; /* functions to merge the values */
44 GstTagFlag flag; /* type of tag */
47 #define TAGLIST "taglist"
48 static GQuark gst_tag_list_quark;
49 static GMutex *__tag_mutex;
50 static GHashTable *__tags;
51 #define TAG_LOCK g_mutex_lock (__tag_mutex)
52 #define TAG_UNLOCK g_mutex_unlock (__tag_mutex)
55 gst_tag_list_get_type (void)
57 static GType _gst_tag_list_type;
59 if (_gst_tag_list_type == 0) {
60 _gst_tag_list_type = g_boxed_type_register_static ("GstTagList",
61 (GBoxedCopyFunc) gst_tag_list_copy,
62 (GBoxedFreeFunc) gst_tag_list_free);
65 g_value_register_transform_func(_gst_tag_list_type, G_TYPE_STRING,
66 _gst_structure_transform_to_string);
70 return _gst_tag_list_type;
74 _gst_tag_initialize (void)
76 gst_tag_list_quark = g_quark_from_static_string (TAGLIST);
77 __tag_mutex = g_mutex_new ();
78 __tags = g_hash_table_new (g_direct_hash, g_direct_equal);
79 gst_tag_register (GST_TAG_TITLE, GST_TAG_FLAG_META,
82 _("commonly used title"),
83 gst_tag_merge_strings_with_comma);
84 gst_tag_register (GST_TAG_ARTIST, GST_TAG_FLAG_META,
87 _("person(s) responsible for the recording"),
88 gst_tag_merge_strings_with_comma);
89 gst_tag_register (GST_TAG_ALBUM, GST_TAG_FLAG_META,
92 _("album containing this data"),
93 gst_tag_merge_strings_with_comma);
94 gst_tag_register (GST_TAG_DATE, GST_TAG_FLAG_META,
95 G_TYPE_UINT, /* FIXME: own data type for dates? */
97 _("date the data was created (in Julian calendar days)"),
99 gst_tag_register (GST_TAG_GENRE, GST_TAG_FLAG_META,
102 _("genre this data belongs to"),
103 gst_tag_merge_strings_with_comma);
104 gst_tag_register (GST_TAG_COMMENT, GST_TAG_FLAG_META,
107 _("free text commenting the data"),
108 gst_tag_merge_strings_with_comma);
109 gst_tag_register (GST_TAG_TRACK_NUMBER, GST_TAG_FLAG_META,
112 _("track number inside a collection"),
113 gst_tag_merge_use_first);
114 gst_tag_register (GST_TAG_TRACK_COUNT, GST_TAG_FLAG_META,
117 _("count of tracks inside collection this track belongs to"),
118 gst_tag_merge_use_first);
119 gst_tag_register (GST_TAG_ALBUM_VOLUME_NUMBER, GST_TAG_FLAG_META,
122 _("disc number inside a collection"),
123 gst_tag_merge_use_first);
124 gst_tag_register (GST_TAG_ALBUM_VOLUME_COUNT, GST_TAG_FLAG_META,
127 _("count of discs inside collection this disc belongs to"),
128 gst_tag_merge_use_first);
129 gst_tag_register (GST_TAG_LOCATION, GST_TAG_FLAG_META,
132 _("original location of file as a URI"),
133 gst_tag_merge_strings_with_comma);
134 gst_tag_register (GST_TAG_DESCRIPTION, GST_TAG_FLAG_META,
137 _("short text describing the content of the data"),
138 gst_tag_merge_strings_with_comma);
139 gst_tag_register (GST_TAG_VERSION, GST_TAG_FLAG_META,
142 _("version of this data"),
144 gst_tag_register (GST_TAG_ISRC, GST_TAG_FLAG_META,
147 _("International Standard Recording Code - see http://www.ifpi.org/isrc/"),
149 gst_tag_register (GST_TAG_ORGANIZATION, GST_TAG_FLAG_META,
152 _("organization"), /* FIXME */
153 gst_tag_merge_strings_with_comma);
154 gst_tag_register (GST_TAG_COPYRIGHT, GST_TAG_FLAG_META,
157 _("copyright notice of the data"),
159 gst_tag_register (GST_TAG_CONTACT, GST_TAG_FLAG_META,
162 _("contact information"),
163 gst_tag_merge_strings_with_comma);
164 gst_tag_register (GST_TAG_LICENSE, GST_TAG_FLAG_META,
167 _("license of data"),
169 gst_tag_register (GST_TAG_PERFORMER, GST_TAG_FLAG_META,
172 _("person(s) performing"),
173 gst_tag_merge_strings_with_comma);
174 gst_tag_register (GST_TAG_DURATION, GST_TAG_FLAG_DECODED,
177 _("length in GStreamer time units (nanoseconds)"),
179 gst_tag_register (GST_TAG_CODEC, GST_TAG_FLAG_ENCODED,
182 _("codec the data is stored in"),
183 gst_tag_merge_strings_with_comma);
184 gst_tag_register (GST_TAG_BITRATE, GST_TAG_FLAG_ENCODED,
187 _("exact or average bitrate in bits/s"),
189 gst_tag_register (GST_TAG_NOMINAL_BITRATE, GST_TAG_FLAG_ENCODED,
191 _("nominal bitrate"),
192 _("nominal bitrate in bits/s"),
194 gst_tag_register (GST_TAG_MINIMUM_BITRATE, GST_TAG_FLAG_ENCODED,
196 _("minimum bitrate"),
197 _("minimum bitrate in bits/s"),
199 gst_tag_register (GST_TAG_MAXIMUM_BITRATE, GST_TAG_FLAG_ENCODED,
201 _("maximum bitrate"),
202 _("maximum bitrate in bits/s"),
204 gst_tag_register (GST_TAG_ENCODER, GST_TAG_FLAG_ENCODED,
207 _("encoder used to encode this stream"),
209 gst_tag_register (GST_TAG_ENCODER_VERSION, GST_TAG_FLAG_ENCODED,
211 _("encoder version"),
212 _("version of the encoder used to encode this stream"),
214 gst_tag_register (GST_TAG_SERIAL, GST_TAG_FLAG_ENCODED,
217 _("serial number of track"),
219 gst_tag_register (GST_TAG_TRACK_GAIN, GST_TAG_FLAG_META,
221 _("replaygain track gain"),
222 _("track gain in db"),
224 gst_tag_register (GST_TAG_TRACK_PEAK, GST_TAG_FLAG_META,
226 _("replaygain track peak"),
227 _("peak of the track"),
229 gst_tag_register (GST_TAG_ALBUM_GAIN, GST_TAG_FLAG_META,
231 _("replaygain album gain"),
232 _("album gain in db"),
234 gst_tag_register (GST_TAG_ALBUM_PEAK, GST_TAG_FLAG_META,
236 _("replaygain album peak"),
237 _("peak of the album"),
241 * gst_tag_merge_use_first:
242 * @dest: uninitialized GValue to store result in
243 * @src: GValue to copy from
245 * This is a convenience function for the func argument of gst_tag_register().
246 * It creates a copy of the first value from the list.
249 gst_tag_merge_use_first (GValue *dest, const GValue *src)
251 const GValue *ret = gst_value_list_get_value (src, 0);
253 g_value_init (dest, G_VALUE_TYPE (ret));
254 g_value_copy (ret, dest);
257 * gst_tag_merge_strings_with_comma:
258 * @dest: uninitialized GValue to store result in
259 * @src: GValue to copy from
261 * This is a convenience function for the func argument of gst_tag_register().
262 * It concatenates all given strings using a comma. The tag must be registered
263 * as a G_TYPE_STRING or this function will fail.
266 gst_tag_merge_strings_with_comma (GValue *dest, const GValue *src)
271 count = gst_value_list_get_size (src);
272 str = g_string_new (g_value_get_string (gst_value_list_get_value (src, 0)));
273 for (i = 1; i < count; i++) {
274 /* seperator between two string */
275 str = g_string_append (str, _(", "));
276 str = g_string_append (str, g_value_get_string (gst_value_list_get_value (src, 1)));
279 g_value_init (dest, G_TYPE_STRING);
280 g_value_set_string_take_ownership (dest, str->str);
281 g_string_free (str, FALSE);
284 gst_tag_lookup (GQuark entry)
289 ret = g_hash_table_lookup (__tags, GUINT_TO_POINTER (entry));
296 * @name: the name or identifier string
297 * @flag: a flag describing the type of tag info
298 * @type: the type this data is in
299 * @nick: human-readable name
300 * @blurb: a human-readable description about this tag
301 * @func: function for merging multiple values of this tag
303 * Registers a new tag type for the use with GStreamer's type system. If a type
304 * with that name is already registered, that one is used.
305 * The old registration may have used a different type however. So don't rely
306 * on your supplied values.
307 * This function takes ownership of all supplied variables.
310 gst_tag_register (gchar *name, GstTagFlag flag, GType type,
311 gchar *nick, gchar *blurb, GstTagMergeFunc func)
316 g_return_if_fail (name != NULL);
317 g_return_if_fail (nick != NULL);
318 g_return_if_fail (blurb != NULL);
319 g_return_if_fail (type != 0 && type != GST_TYPE_LIST);
321 key = g_quark_from_string (name);
322 info = gst_tag_lookup (key);
323 g_return_if_fail (info == NULL);
325 info = g_new (GstTagInfo, 1);
330 info->merge_func = func;
333 g_hash_table_insert (__tags, GUINT_TO_POINTER (key), info);
338 * @tag: name of the tag
340 * Checks if the given type is already registered.
342 * Returns: TRUE if the type is already registered
345 gst_tag_exists (const gchar *tag)
347 g_return_val_if_fail (tag != NULL, FALSE);
349 return gst_tag_lookup (g_quark_from_string (tag)) != NULL;
355 * Gets the #GType used for this tag.
357 * Returns: the #GType of this tag
360 gst_tag_get_type (const gchar *tag)
364 g_return_val_if_fail (tag != NULL, 0);
365 info = gst_tag_lookup (g_quark_from_string (tag));
366 g_return_val_if_fail (info != NULL, 0);
374 * Returns the human-readable name of this tag, You must not change or free
377 * Returns: the human-readable name of this tag
380 gst_tag_get_nick (const gchar *tag)
384 g_return_val_if_fail (tag != NULL, NULL);
385 info = gst_tag_lookup (g_quark_from_string (tag));
386 g_return_val_if_fail (info != NULL, NULL);
391 * gst_tag_get_description:
394 * Returns the human-readable description of this tag, You must not change or
397 * Return the human-readable description of this tag
400 gst_tag_get_description (const gchar *tag)
404 g_return_val_if_fail (tag != NULL, NULL);
405 info = gst_tag_lookup (g_quark_from_string (tag));
406 g_return_val_if_fail (info != NULL, NULL);
411 * gst_tag_list_is_fixed:
414 * Checks if the given tag is fixed. A fixed tag can only contain one value.
415 * Unfixed tags can contain lists of values.
417 * Returns: TRUE, if the given tag is fixed.
420 gst_tag_is_fixed (const gchar *tag)
424 g_return_val_if_fail (tag != NULL, FALSE);
425 info = gst_tag_lookup (g_quark_from_string (tag));
426 g_return_val_if_fail (info != NULL, FALSE);
428 return info->merge_func == NULL;
433 * Creates a new empty GstTagList.
435 * Returns: An empty tag list
438 gst_tag_list_new (void)
440 return GST_TAG_LIST (gst_structure_new (TAGLIST, NULL));
444 * @p: Object that might be a taglist
446 * Checks if the given pointer is a taglist.
448 * Returns: TRUE, if the given pointer is a taglist
451 gst_is_tag_list (gconstpointer p)
453 g_return_val_if_fail (p != NULL, FALSE);
455 return ((GstStructure *) p)->name == gst_tag_list_quark;
459 GstTagMergeMode mode;
462 gst_tag_list_add_value_internal (GstStructure *list, GstTagMergeMode mode, GQuark tag, GValue *value)
464 GstTagInfo *info = gst_tag_lookup (tag);
465 const GValue *value2;
467 g_assert (info != NULL);
469 if (info->merge_func && (value2 = gst_structure_id_get_value (list, tag)) != NULL) {
470 GValue dest = { 0, };
472 case GST_TAG_MERGE_REPLACE_ALL:
473 case GST_TAG_MERGE_REPLACE:
474 gst_structure_id_set_value (list, tag, value);
476 case GST_TAG_MERGE_PREPEND:
477 gst_value_list_concat (&dest, value, value2);
478 gst_structure_id_set_value (list, tag, &dest);
479 g_value_unset (&dest);
481 case GST_TAG_MERGE_APPEND:
482 gst_value_list_concat (&dest, value2, value);
483 gst_structure_id_set_value (list, tag, &dest);
484 g_value_unset (&dest);
486 case GST_TAG_MERGE_KEEP:
487 case GST_TAG_MERGE_KEEP_ALL:
490 g_assert_not_reached ();
495 case GST_TAG_MERGE_APPEND:
496 case GST_TAG_MERGE_KEEP:
497 if (gst_structure_id_get_value (list, tag) != NULL)
500 case GST_TAG_MERGE_REPLACE_ALL:
501 case GST_TAG_MERGE_REPLACE:
502 case GST_TAG_MERGE_PREPEND:
503 gst_structure_id_set_value (list, tag, value);
505 case GST_TAG_MERGE_KEEP_ALL:
508 g_assert_not_reached ();
514 gst_tag_list_copy_foreach (GQuark tag, GValue *value, gpointer user_data)
516 GstTagCopyData *copy = (GstTagCopyData *) user_data;
518 gst_tag_list_add_value_internal (copy->list, copy->mode, tag, value);
523 * gst_tag_list_insert:
524 * @into: list to merge into
525 * @from: list to merge from
526 * @mode: the mode to use
528 * Inserts the tags of the second list into the first list using the given mode.
531 gst_tag_list_insert (GstTagList *into, const GstTagList *from, GstTagMergeMode mode)
535 g_return_if_fail (GST_IS_TAG_LIST (into));
536 g_return_if_fail (GST_IS_TAG_LIST (from));
537 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
539 data.list = (GstStructure *) into;
541 if (mode == GST_TAG_MERGE_REPLACE_ALL) {
542 gst_structure_remove_all_fields (data.list);
544 gst_structure_foreach ((GstStructure *) from, gst_tag_list_copy_foreach, &data);
548 * @list: list to copy
550 * Copies a given #GstTagList.
552 * Returns: copy of the given list
555 gst_tag_list_copy (const GstTagList *list)
557 g_return_val_if_fail (GST_IS_TAG_LIST (list), NULL);
559 return GST_TAG_LIST (gst_structure_copy ((GstStructure *) list));
562 * gst_tag_list_merge:
563 * @list1: first list to merge
564 * @list2: second list to merge
565 * @mode: the mode to use
567 * Merges the two given lists into a new list. If one of the lists is NULL, a
568 * copy of the other is returned. If both lists are NULL, NULL is returned.
570 * Returns: the new list
573 gst_tag_list_merge (const GstTagList *list1, const GstTagList *list2, GstTagMergeMode mode)
575 g_return_val_if_fail (list1 == NULL || GST_IS_TAG_LIST (list1), NULL);
576 g_return_val_if_fail (list2 == NULL || GST_IS_TAG_LIST (list2), NULL);
577 g_return_val_if_fail (GST_TAG_MODE_IS_VALID (mode), NULL);
579 if (!list1 && !list2) {
582 return gst_tag_list_copy (list2);
584 return gst_tag_list_copy (list1);
588 ret = gst_tag_list_copy (list1);
589 gst_tag_list_insert (ret, list2, mode);
595 * @list: the list to free
597 * Frees the given list and all associated values.
600 gst_tag_list_free (GstTagList *list)
602 g_return_if_fail (GST_IS_TAG_LIST (list));
603 gst_structure_free ((GstStructure *) list);
606 * gst_tag_list_get_tag_size:
608 * @tag: the tag to query
610 * Checks how many value are stored in this tag list for the given tag.
612 * Returns: The number of tags stored
615 gst_tag_list_get_tag_size (const GstTagList *list, const gchar *tag)
619 g_return_val_if_fail (GST_IS_TAG_LIST (list), 0);
621 value = gst_structure_get_value ((GstStructure *) list, tag);
624 if (G_VALUE_TYPE (value) != GST_TYPE_LIST)
627 return gst_value_list_get_size (value);
631 * @list: list to set tags in
632 * @mode: the mode to use
634 * @...: NULL-terminated list of values to set
636 * Sets the values for the given tags using the specified mode.
639 gst_tag_list_add (GstTagList *list, GstTagMergeMode mode, const gchar *tag, ...)
643 g_return_if_fail (GST_IS_TAG_LIST (list));
644 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
645 g_return_if_fail (tag != NULL);
647 va_start (args, tag);
648 gst_tag_list_add_valist (list, mode, tag, args);
652 * gst_tag_list_add_values:
653 * @list: list to set tags in
654 * @mode: the mode to use
656 * @...: GValues to set
658 * Sets the GValues for the given tags using the specified mode.
661 gst_tag_list_add_values (GstTagList *list, GstTagMergeMode mode, const gchar *tag, ...)
665 g_return_if_fail (GST_IS_TAG_LIST (list));
666 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
667 g_return_if_fail (tag != NULL);
669 va_start (args, tag);
670 gst_tag_list_add_valist_values (list, mode, tag, args);
674 * gst_tag_list_add_valist:
675 * @list: list to set tags in
676 * @mode: the mode to use
678 * @var_args: tag / value pairs to set
680 * Sets the values for the given tags using the specified mode.
683 gst_tag_list_add_valist (GstTagList *list, GstTagMergeMode mode, const gchar *tag, va_list var_args)
689 g_return_if_fail (GST_IS_TAG_LIST (list));
690 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
691 g_return_if_fail (tag != NULL);
693 while (tag != NULL) {
694 GValue value = { 0, };
695 quark = g_quark_from_string (tag);
696 info = gst_tag_lookup (quark);
698 g_warning ("no GstTag for %s", tag);
699 g_return_if_fail (info != NULL);
700 g_value_init (&value, info->type);
701 G_VALUE_COLLECT (&value, var_args, 0, &error);
703 g_warning ("%s: %s", G_STRLOC, error);
705 /* we purposely leak the value here, it might not be
706 * in a sane state if an error condition occoured
710 gst_tag_list_add_value_internal (list, mode, quark, &value);
711 g_value_unset (&value);
712 tag = va_arg (var_args, gchar *);
716 * gst_tag_list_add_valist_values:
717 * @list: list to set tags in
718 * @mode: the mode to use
720 * @var_args: tag / GValue pairs to set
722 * Sets the GValues for the given tags using the specified mode.
725 gst_tag_list_add_valist_values (GstTagList *list, GstTagMergeMode mode, const gchar *tag, va_list var_args)
730 g_return_if_fail (GST_IS_TAG_LIST (list));
731 g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
732 g_return_if_fail (tag != NULL);
734 while (tag != NULL) {
735 quark = g_quark_from_string (tag);
736 info = gst_tag_lookup (quark);
737 g_return_if_fail (info != NULL);
738 gst_tag_list_add_value_internal (list, mode, quark, va_arg (var_args, GValue *));
739 tag = va_arg (var_args, gchar *);
743 * gst_tag_list_remove_tag:
744 * @list: list to remove tag from
745 * @tag: tag to remove
747 * Removes the goven tag from the taglist.
750 gst_tag_list_remove_tag (GstTagList *list, const gchar *tag)
752 g_return_if_fail (GST_IS_TAG_LIST (list));
753 g_return_if_fail (tag != NULL);
755 gst_structure_remove_field ((GstStructure *) list, tag);
758 GstTagForeachFunc func;
759 GstTagList * tag_list;
763 structure_foreach_wrapper (GQuark field_id,
764 GValue *value, gpointer user_data)
766 TagForeachData *data = (TagForeachData *) user_data;
767 data->func (data->tag_list, g_quark_to_string (field_id), data->data);
771 * gst_tag_list_foreach:
772 * @list: list to iterate over
773 * @func: function to be called for each tag
774 * @user_data: user specified data
776 * Calls the given function for each tag inside the tag list. Note that if there
777 * is no tag, the function won't be called at all.
780 gst_tag_list_foreach (GstTagList *list, GstTagForeachFunc func, gpointer user_data)
784 g_return_if_fail (GST_IS_TAG_LIST (list));
785 g_return_if_fail (func != NULL);
788 data.tag_list = list;
789 data.data = user_data;
790 gst_structure_foreach ((GstStructure *) list, structure_foreach_wrapper, &data);
793 /***** tag events *****/
797 * @list: the tag list to put into the event or NULL for an empty list
799 * Creates a new tag event with the given list and takes ownership of it.
801 * Returns: a new tag event
804 gst_event_new_tag (GstTagList *list)
808 g_return_val_if_fail (list == NULL || GST_IS_TAG_LIST (list), NULL);
810 ret = gst_event_new (GST_EVENT_TAG);
812 list = gst_tag_list_new ();
813 ret->event_data.structure.structure = (GstStructure *) list;
818 * get_event_tag_get_list:
819 * @tag_event: a tagging #GstEvent
821 * Gets the taglist from a given tagging event.
823 * Returns: The #GstTagList of the event
826 gst_event_tag_get_list (GstEvent *tag_event)
828 g_return_val_if_fail (GST_IS_EVENT (tag_event), NULL);
829 g_return_val_if_fail (GST_EVENT_TYPE (tag_event) == GST_EVENT_TAG, NULL);
831 return GST_TAG_LIST (tag_event->event_data.structure.structure);
835 * gst_tag_list_get_value_index:
836 * @list: a #GStTagList
837 * @tag: tag to read out
838 * @index: number of entry to read out
840 * Gets the value that is at the given index for the given tag in the given
843 * Returns: The GValue for the specified entry or NULL if the tag wasn't available
844 * or the tag doesn't have as many entries
846 G_CONST_RETURN GValue *
847 gst_tag_list_get_value_index (const GstTagList *list, const gchar *tag, guint index)
851 g_return_val_if_fail (GST_IS_TAG_LIST (list), NULL);
852 g_return_val_if_fail (tag != NULL, NULL);
854 value = gst_structure_get_value ((GstStructure *) list, tag);
855 if (value == NULL) return NULL;
857 if (GST_VALUE_HOLDS_LIST (value)) {
858 if (index >= gst_value_list_get_size (value)) return NULL;
859 return gst_value_list_get_value (value, index);
861 if (index > 0) return NULL;
867 * gst_tag_list_copy_value:
868 * @dest: uninitialized #GValue to copy into
869 * @list: list to get the tag from
870 * @tag: tag to read out
872 * Copies the contents for the given tag into the value, merging multiple values
873 * into one if multiple values are associated with the tag.
874 * You must g_value_unset() the value after use.
876 * Returns: TRUE, if a value was copied, FALSE if the tag didn't exist in the
880 gst_tag_list_copy_value (GValue *dest, const GstTagList *list, const gchar *tag)
884 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE);
885 g_return_val_if_fail (tag != NULL, FALSE);
886 g_return_val_if_fail (dest != NULL, FALSE);
887 g_return_val_if_fail (G_VALUE_TYPE (dest) == 0, FALSE);
889 src = gst_structure_get_value ((GstStructure *) list, tag);
890 if (!src) return FALSE;
892 if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
893 GstTagInfo *info = gst_tag_lookup (g_quark_from_string (tag));
894 /* must be there or lists aren't allowed */
895 g_assert (info->merge_func);
896 info->merge_func (dest, src);
898 g_value_init (dest, G_VALUE_TYPE (src));
899 g_value_copy (src, dest);
904 /***** evil macros to get all the gst_tag_list_get_*() functions right *****/
906 #define TAG_MERGE_FUNCS(name,type) \
908 gst_tag_list_get_ ## name (const GstTagList *list, const gchar *tag, \
913 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE); \
914 g_return_val_if_fail (tag != NULL, FALSE); \
915 g_return_val_if_fail (value != NULL, FALSE); \
917 if (!gst_tag_list_copy_value (&v, list, tag)) \
919 *value = COPY_FUNC (g_value_get_ ## name (&v)); \
920 g_value_unset (&v); \
925 gst_tag_list_get_ ## name ## _index (const GstTagList *list, const gchar *tag, \
926 guint index, type *value) \
930 g_return_val_if_fail (GST_IS_TAG_LIST (list), FALSE); \
931 g_return_val_if_fail (tag != NULL, FALSE); \
932 g_return_val_if_fail (value != NULL, FALSE); \
934 if ((v = gst_tag_list_get_value_index (list, tag, index)) == NULL) \
936 *value = COPY_FUNC (g_value_get_ ## name (v)); \
940 #define COPY_FUNC /**/
941 TAG_MERGE_FUNCS (char, gchar)
942 TAG_MERGE_FUNCS (uchar, guchar)
943 TAG_MERGE_FUNCS (boolean, gboolean)
944 TAG_MERGE_FUNCS (int, gint)
945 TAG_MERGE_FUNCS (uint, guint)
946 TAG_MERGE_FUNCS (long, glong)
947 TAG_MERGE_FUNCS (ulong, gulong)
948 TAG_MERGE_FUNCS (int64, gint64)
949 TAG_MERGE_FUNCS (uint64, guint64)
950 TAG_MERGE_FUNCS (float, gfloat)
951 TAG_MERGE_FUNCS (double, gdouble)
954 #define COPY_FUNC g_strdup
955 TAG_MERGE_FUNCS (string, gchar *)