2 * Copyright (C) <2003> David A. Schleef <ds@schleef.org>
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
14 * You should have received a copy of the GNU Library General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
22 * @short_description: Structure describing sets of media formats
23 * @see_also: #GstStructure
25 * Caps (capabilities) are lighweight refcounted objects describing media types.
26 * They are composed of an array of #GstStructure.
28 * Caps are exposed on #GstPadTemplate to describe all possible types a
29 * given pad can handle. They are also stored in the #GstRegistry along with
30 * a description of the #GstElement.
32 * Caps are exposed on the element pads using the gst_pad_get_caps() pad
33 * function. This function describes the possible types that the pad can
34 * handle or produce at runtime.
36 * Caps are also attached to buffers to describe to content of the data
37 * pointed to by the buffer with gst_buffer_set_caps(). Caps attached to
38 * a #GstBuffer allow for format negotiation upstream and downstream.
40 * A #GstCaps can be constructed with the following code fragment:
43 * <title>Creating caps</title>
46 * caps = gst_caps_new_simple ("video/x-raw-yuv",
47 * "format", GST_TYPE_FOURCC, GST_MAKE_FOURCC ('I', '4', '2', '0'),
48 * "framerate", GST_TYPE_FRACTION, 25, 1,
49 * "pixel-aspect-ratio", GST_TYPE_FRACTION, 1, 1,
50 * "width", G_TYPE_INT, 320,
51 * "height", G_TYPE_INT, 240,
56 * A #GstCaps is fixed when it has no properties with ranges or lists. Use
57 * gst_caps_is_fixed() to test for fixed caps. Only fixed caps can be
58 * set on a #GstPad or #GstBuffer.
60 * Various methods exist to work with the media types such as subtracting
63 * Last reviewed on 2007-02-13 (0.10.10)
72 #include "gst_private.h"
75 #define DEBUG_REFCOUNT
77 #define CAPS_POISON(caps) G_STMT_START{ \
79 GstCaps *_newcaps = gst_caps_copy (caps); \
80 gst_caps_unref(caps); \
84 #define STRUCTURE_POISON(structure) G_STMT_START{ \
86 GstStructure *_newstruct = gst_structure_copy (structure); \
87 gst_structure_free(structure); \
88 structure = _newstruct; \
91 #define IS_WRITABLE(caps) \
92 (g_atomic_int_get (&(caps)->refcount) == 1)
94 /* quick way to get a caps structure at an index without doing a type or array
96 #define gst_caps_get_structure_unchecked(caps, index) \
97 ((GstStructure *)g_ptr_array_index ((caps)->structs, (index)))
100 /* lock to protect multiple invocations of static caps to caps conversion */
101 G_LOCK_DEFINE_STATIC (static_caps_lock);
103 static void gst_caps_transform_to_string (const GValue * src_value,
104 GValue * dest_value);
105 static gboolean gst_caps_from_string_inplace (GstCaps * caps,
106 const gchar * string);
107 static GstCaps *gst_caps_copy_conditional (GstCaps * src);
110 gst_caps_get_type (void)
112 static GType gst_caps_type = 0;
114 if (G_UNLIKELY (gst_caps_type == 0)) {
115 gst_caps_type = g_boxed_type_register_static ("GstCaps",
116 (GBoxedCopyFunc) gst_caps_copy_conditional,
117 (GBoxedFreeFunc) gst_caps_unref);
119 g_value_register_transform_func (gst_caps_type,
120 G_TYPE_STRING, gst_caps_transform_to_string);
123 return gst_caps_type;
126 /* creation/deletion */
129 * gst_caps_new_empty:
131 * Creates a new #GstCaps that is empty. That is, the returned
132 * #GstCaps contains no media formats.
133 * Caller is responsible for unreffing the returned caps.
135 * Returns: the new #GstCaps
138 gst_caps_new_empty (void)
140 GstCaps *caps = g_slice_new (GstCaps);
142 caps->type = GST_TYPE_CAPS;
145 caps->structs = g_ptr_array_new ();
147 #ifdef DEBUG_REFCOUNT
148 GST_CAT_LOG (GST_CAT_CAPS, "created caps %p", caps);
157 * Creates a new #GstCaps that indicates that it is compatible with
160 * Returns: the new #GstCaps
163 gst_caps_new_any (void)
165 GstCaps *caps = gst_caps_new_empty ();
167 caps->flags = GST_CAPS_FLAGS_ANY;
173 * gst_caps_new_simple:
174 * @media_type: the media type of the structure
175 * @fieldname: first field to set
176 * @...: additional arguments
178 * Creates a new #GstCaps that contains one #GstStructure. The
179 * structure is defined by the arguments, which have the same format
180 * as gst_structure_new().
181 * Caller is responsible for unreffing the returned caps.
183 * Returns: the new #GstCaps
186 gst_caps_new_simple (const char *media_type, const char *fieldname, ...)
189 GstStructure *structure;
192 caps = gst_caps_new_empty ();
194 va_start (var_args, fieldname);
195 structure = gst_structure_new_valist (media_type, fieldname, var_args);
198 gst_caps_append_structure (caps, structure);
205 * @struct1: the first structure to add
206 * @...: additional structures to add
208 * Creates a new #GstCaps and adds all the structures listed as
209 * arguments. The list must be NULL-terminated. The structures
210 * are not copied; the returned #GstCaps owns the structures.
212 * Returns: the new #GstCaps
215 gst_caps_new_full (GstStructure * struct1, ...)
220 va_start (var_args, struct1);
221 caps = gst_caps_new_full_valist (struct1, var_args);
228 * gst_caps_new_full_valist:
229 * @structure: the first structure to add
230 * @var_args: additional structures to add
232 * Creates a new #GstCaps and adds all the structures listed as
233 * arguments. The list must be NULL-terminated. The structures
234 * are not copied; the returned #GstCaps owns the structures.
236 * Returns: the new #GstCaps
239 gst_caps_new_full_valist (GstStructure * structure, va_list var_args)
243 caps = gst_caps_new_empty ();
246 gst_caps_append_structure (caps, structure);
247 structure = va_arg (var_args, GstStructure *);
255 * @caps: the #GstCaps to copy
257 * Creates a new #GstCaps as a copy of the old @caps. The new caps will have a
258 * refcount of 1, owned by the caller. The structures are copied as well.
260 * Note that this function is the semantic equivalent of a gst_caps_ref()
261 * followed by a gst_caps_make_writable(). If you only want to hold on to a
262 * reference to the data, you should use gst_caps_ref().
264 * When you are finished with the caps, call gst_caps_unref() on it.
266 * Returns: the new #GstCaps
269 gst_caps_copy (const GstCaps * caps)
272 GstStructure *structure;
275 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
277 newcaps = gst_caps_new_empty ();
278 newcaps->flags = caps->flags;
279 n = caps->structs->len;
281 for (i = 0; i < n; i++) {
282 structure = gst_caps_get_structure_unchecked (caps, i);
283 gst_caps_append_structure (newcaps, gst_structure_copy (structure));
290 _gst_caps_free (GstCaps * caps)
292 GstStructure *structure;
295 /* The refcount must be 0, but since we're only called by gst_caps_unref,
296 * don't bother testing. */
297 len = caps->structs->len;
298 for (i = 0; i < len; i++) {
299 structure = (GstStructure *) gst_caps_get_structure_unchecked (caps, i);
300 gst_structure_set_parent_refcount (structure, NULL);
301 gst_structure_free (structure);
303 g_ptr_array_free (caps->structs, TRUE);
305 memset (caps, 0xff, sizeof (GstCaps));
308 #ifdef DEBUG_REFCOUNT
309 GST_CAT_LOG (GST_CAT_CAPS, "freeing caps %p", caps);
311 g_slice_free (GstCaps, caps);
315 * gst_caps_make_writable:
316 * @caps: the #GstCaps to make writable
318 * Returns a writable copy of @caps.
320 * If there is only one reference count on @caps, the caller must be the owner,
321 * and so this function will return the caps object unchanged. If on the other
322 * hand there is more than one reference on the object, a new caps object will
323 * be returned. The caller's reference on @caps will be removed, and instead the
324 * caller will own a reference to the returned object.
326 * In short, this function unrefs the caps in the argument and refs the caps
327 * that it returns. Don't access the argument after calling this function. See
328 * also: gst_caps_ref().
330 * Returns: the same #GstCaps object.
333 gst_caps_make_writable (GstCaps * caps)
337 g_return_val_if_fail (caps != NULL, NULL);
339 /* we are the only instance reffing this caps */
340 if (g_atomic_int_get (&caps->refcount) == 1)
344 copy = gst_caps_copy (caps);
345 gst_caps_unref (caps);
352 * @caps: the #GstCaps to reference
354 * Add a reference to a #GstCaps object.
356 * From this point on, until the caller calls gst_caps_unref() or
357 * gst_caps_make_writable(), it is guaranteed that the caps object will not
358 * change. This means its structures won't change, etc. To use a #GstCaps
359 * object, you must always have a refcount on it -- either the one made
360 * implicitly by gst_caps_new(), or via taking one explicitly with this
363 * Returns: the same #GstCaps object.
366 gst_caps_ref (GstCaps * caps)
368 g_return_val_if_fail (caps != NULL, NULL);
370 #ifdef DEBUG_REFCOUNT
371 GST_CAT_LOG (GST_CAT_REFCOUNTING, "%p %d->%d", caps,
372 GST_CAPS_REFCOUNT_VALUE (caps), GST_CAPS_REFCOUNT_VALUE (caps) + 1);
374 g_return_val_if_fail (GST_CAPS_REFCOUNT_VALUE (caps) > 0, NULL);
376 g_atomic_int_inc (&caps->refcount);
383 * @caps: the #GstCaps to unref
385 * Unref a #GstCaps and and free all its structures and the
386 * structures' values when the refcount reaches 0.
389 gst_caps_unref (GstCaps * caps)
391 g_return_if_fail (caps != NULL);
393 #ifdef DEBUG_REFCOUNT
394 GST_CAT_LOG (GST_CAT_REFCOUNTING, "%p %d->%d", caps,
395 GST_CAPS_REFCOUNT_VALUE (caps), GST_CAPS_REFCOUNT_VALUE (caps) - 1);
398 g_return_if_fail (GST_CAPS_REFCOUNT_VALUE (caps) > 0);
400 /* if we ended up with the refcount at zero, free the caps */
401 if (G_UNLIKELY (g_atomic_int_dec_and_test (&caps->refcount)))
402 _gst_caps_free (caps);
406 gst_static_caps_get_type (void)
408 static GType staticcaps_type = 0;
410 if (G_UNLIKELY (staticcaps_type == 0)) {
411 staticcaps_type = g_pointer_type_register_static ("GstStaticCaps");
413 return staticcaps_type;
418 * gst_static_caps_get:
419 * @static_caps: the #GstStaticCaps to convert
421 * Converts a #GstStaticCaps to a #GstCaps.
423 * Returns: A pointer to the #GstCaps. Unref after usage. Since the
424 * core holds an additional ref to the returned caps,
425 * use gst_caps_make_writable() on the returned caps to modify it.
428 gst_static_caps_get (GstStaticCaps * static_caps)
432 g_return_val_if_fail (static_caps != NULL, NULL);
434 caps = (GstCaps *) static_caps;
436 /* refcount is 0 when we need to convert */
437 if (G_UNLIKELY (g_atomic_int_get (&caps->refcount) == 0)) {
441 G_LOCK (static_caps_lock);
442 /* check if other thread already updated */
443 if (G_UNLIKELY (g_atomic_int_get (&caps->refcount) > 0))
446 string = static_caps->string;
448 if (G_UNLIKELY (string == NULL))
451 GST_CAT_LOG (GST_CAT_CAPS, "creating %p", static_caps);
453 /* we construct the caps on the stack, then copy over the struct into our
454 * real caps, refcount last. We do this because we must leave the refcount
455 * of the result caps to 0 so that other threads don't run away with the
456 * caps while we are constructing it. */
457 temp.type = GST_TYPE_CAPS;
459 temp.structs = g_ptr_array_new ();
461 /* initialize the caps to a refcount of 1 so the caps can be writable for
462 * the next statement */
465 /* convert to string */
466 if (G_UNLIKELY (!gst_caps_from_string_inplace (&temp, string)))
467 g_critical ("Could not convert static caps \"%s\"", string);
469 /* now copy stuff over to the real caps. */
470 caps->type = temp.type;
471 caps->flags = temp.flags;
472 caps->structs = temp.structs;
473 /* and bump the refcount so other threads can now read */
474 g_atomic_int_set (&caps->refcount, 1);
476 GST_CAT_LOG (GST_CAT_CAPS, "created %p", static_caps);
478 G_UNLOCK (static_caps_lock);
480 /* ref the caps, makes it not writable */
488 G_UNLOCK (static_caps_lock);
489 g_warning ("static caps %p string is NULL", static_caps);
495 static GstStructure *
496 gst_caps_remove_and_get_structure (GstCaps * caps, guint idx)
498 /* don't use index_fast, gst_caps_do_simplify relies on the order */
499 GstStructure *s = g_ptr_array_remove_index (caps->structs, idx);
501 gst_structure_set_parent_refcount (s, NULL);
506 gst_structure_is_equal_foreach (GQuark field_id, const GValue * val2,
509 GstStructure *struct1 = (GstStructure *) data;
510 const GValue *val1 = gst_structure_id_get_value (struct1, field_id);
514 if (gst_value_compare (val1, val2) == GST_VALUE_EQUAL) {
522 gst_caps_structure_is_subset_field (GQuark field_id, const GValue * value,
525 GstStructure *subtract_from = user_data;
526 GValue subtraction = { 0, };
529 if (!(other = gst_structure_id_get_value (subtract_from, field_id)))
530 /* field is missing in one set */
533 /* equal values are subset */
534 if (gst_value_compare (other, value) == GST_VALUE_EQUAL)
542 * -> 1 - [1,2] = empty
546 * -> [1,2] - [1,3] = empty
550 * -> {1,3} - {1,2} = 3
553 * First caps subtraction needs to return a non-empty set, second
554 * subtractions needs to give en empty set.
556 if (gst_value_subtract (&subtraction, other, value)) {
557 g_value_unset (&subtraction);
558 /* !empty result, swapping must be empty */
559 if (!gst_value_subtract (&subtraction, value, other))
562 g_value_unset (&subtraction);
568 gst_caps_structure_is_subset (const GstStructure * minuend,
569 const GstStructure * subtrahend)
571 if ((minuend->name != subtrahend->name) ||
572 (gst_structure_n_fields (minuend) !=
573 gst_structure_n_fields (subtrahend))) {
577 return gst_structure_foreach ((GstStructure *) subtrahend,
578 gst_caps_structure_is_subset_field, (gpointer) minuend);
583 * @caps1: the #GstCaps that will be appended to
584 * @caps2: the #GstCaps to append
586 * Appends the structures contained in @caps2 to @caps1. The structures in
587 * @caps2 are not copied -- they are transferred to @caps1, and then @caps2 is
588 * freed. If either caps is ANY, the resulting caps will be ANY.
591 gst_caps_append (GstCaps * caps1, GstCaps * caps2)
593 GstStructure *structure;
596 g_return_if_fail (GST_IS_CAPS (caps1));
597 g_return_if_fail (GST_IS_CAPS (caps2));
598 g_return_if_fail (IS_WRITABLE (caps1));
599 g_return_if_fail (IS_WRITABLE (caps2));
604 if (gst_caps_is_any (caps1) || gst_caps_is_any (caps2)) {
605 /* FIXME: this leaks */
606 caps1->flags |= GST_CAPS_FLAGS_ANY;
607 for (i = caps2->structs->len - 1; i >= 0; i--) {
608 structure = gst_caps_remove_and_get_structure (caps2, i);
609 gst_structure_free (structure);
612 for (i = caps2->structs->len; i; i--) {
613 structure = gst_caps_remove_and_get_structure (caps2, 0);
614 gst_caps_append_structure (caps1, structure);
617 gst_caps_unref (caps2); /* guaranteed to free it */
622 * @caps1: the #GstCaps that will take the new entries
623 * @caps2: the #GstCaps to merge in
625 * Appends the structures contained in @caps2 to @caps1 if they are not yet
626 * expressed by @caps1. The structures in @caps2 are not copied -- they are
627 * transferred to @caps1, and then @caps2 is freed.
628 * If either caps is ANY, the resulting caps will be ANY.
633 gst_caps_merge (GstCaps * caps1, GstCaps * caps2)
635 GstStructure *structure;
638 g_return_if_fail (GST_IS_CAPS (caps1));
639 g_return_if_fail (GST_IS_CAPS (caps2));
640 g_return_if_fail (IS_WRITABLE (caps1));
641 g_return_if_fail (IS_WRITABLE (caps2));
646 if (gst_caps_is_any (caps1)) {
647 for (i = caps2->structs->len - 1; i >= 0; i--) {
648 structure = gst_caps_remove_and_get_structure (caps2, i);
649 gst_structure_free (structure);
651 } else if (gst_caps_is_any (caps2)) {
652 caps1->flags |= GST_CAPS_FLAGS_ANY;
653 for (i = caps1->structs->len - 1; i >= 0; i--) {
654 structure = gst_caps_remove_and_get_structure (caps1, i);
655 gst_structure_free (structure);
658 for (i = caps2->structs->len; i; i--) {
659 structure = gst_caps_remove_and_get_structure (caps2, 0);
660 gst_caps_merge_structure (caps1, structure);
663 GstCaps *com = gst_caps_intersect (caps1, caps2);
664 GstCaps *add = gst_caps_subtract (caps2, com);
666 GST_DEBUG ("common : %d", gst_caps_get_size (com));
667 GST_DEBUG ("adding : %d", gst_caps_get_size (add));
668 gst_caps_append (caps1, add);
669 gst_caps_unref (com);
672 gst_caps_unref (caps2); /* guaranteed to free it */
676 * gst_caps_append_structure:
677 * @caps: the #GstCaps that will be appended to
678 * @structure: the #GstStructure to append
680 * Appends @structure to @caps. The structure is not copied; @caps
681 * becomes the owner of @structure.
684 gst_caps_append_structure (GstCaps * caps, GstStructure * structure)
686 g_return_if_fail (GST_IS_CAPS (caps));
687 g_return_if_fail (IS_WRITABLE (caps));
689 if (G_LIKELY (structure)) {
690 g_return_if_fail (structure->parent_refcount == NULL);
693 STRUCTURE_POISON (structure);
696 gst_structure_set_parent_refcount (structure, &caps->refcount);
697 g_ptr_array_add (caps->structs, structure);
702 * gst_caps_remove_structure:
703 * @caps: the #GstCaps to remove from
704 * @idx: Index of the structure to remove
706 * removes the stucture with the given index from the list of structures
707 * contained in @caps.
710 gst_caps_remove_structure (GstCaps * caps, guint idx)
712 GstStructure *structure;
714 g_return_if_fail (caps != NULL);
715 g_return_if_fail (idx <= gst_caps_get_size (caps));
716 g_return_if_fail (IS_WRITABLE (caps));
718 structure = gst_caps_remove_and_get_structure (caps, idx);
719 gst_structure_free (structure);
723 * gst_caps_merge_structure:
724 * @caps: the #GstCaps that will the the new structure
725 * @structure: the #GstStructure to merge
727 * Appends @structure to @caps if its not already expressed by @caps. The
728 * structure is not copied; @caps becomes the owner of @structure.
731 gst_caps_merge_structure (GstCaps * caps, GstStructure * structure)
733 g_return_if_fail (GST_IS_CAPS (caps));
734 g_return_if_fail (IS_WRITABLE (caps));
736 if (G_LIKELY (structure)) {
737 GstStructure *structure1;
739 gboolean unique = TRUE;
741 g_return_if_fail (structure->parent_refcount == NULL);
744 STRUCTURE_POISON (structure);
747 /* check each structure */
748 for (i = caps->structs->len - 1; i >= 0; i--) {
749 structure1 = gst_caps_get_structure_unchecked (caps, i);
750 /* if structure is a subset of structure1, then skip it */
751 if (gst_caps_structure_is_subset (structure1, structure)) {
757 gst_structure_set_parent_refcount (structure, &caps->refcount);
758 g_ptr_array_add (caps->structs, structure);
760 gst_structure_free (structure);
770 * Gets the number of structures contained in @caps.
772 * Returns: the number of structures that @caps contains
775 gst_caps_get_size (const GstCaps * caps)
777 g_return_val_if_fail (GST_IS_CAPS (caps), 0);
779 return caps->structs->len;
783 * gst_caps_get_structure:
785 * @index: the index of the structure
787 * Finds the structure in @caps that has the index @index, and
790 * WARNING: This function takes a const GstCaps *, but returns a
791 * non-const GstStructure *. This is for programming convenience --
792 * the caller should be aware that structures inside a constant
793 * #GstCaps should not be modified. However, if you know the caps
794 * are writable, either because you have just copied them or made
795 * them writable with gst_caps_make_writable(), you may modify the
796 * structure returned in the usual way, e.g. with functions like
797 * gst_structure_set_simple().
799 * You do not need to free or unref the structure returned, it
800 * belongs to the #GstCaps.
802 * Returns: a pointer to the #GstStructure corresponding to @index
805 gst_caps_get_structure (const GstCaps * caps, guint index)
807 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
808 g_return_val_if_fail (index < caps->structs->len, NULL);
810 return gst_caps_get_structure_unchecked (caps, index);
815 * @caps: the #GstCaps to copy
816 * @nth: the nth structure to copy
818 * Creates a new #GstCaps and appends a copy of the nth structure
819 * contained in @caps.
821 * Returns: the new #GstCaps
824 gst_caps_copy_nth (const GstCaps * caps, guint nth)
827 GstStructure *structure;
829 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
831 newcaps = gst_caps_new_empty ();
832 newcaps->flags = caps->flags;
834 if (caps->structs->len > nth) {
835 structure = gst_caps_get_structure_unchecked (caps, nth);
836 gst_caps_append_structure (newcaps, gst_structure_copy (structure));
844 * @caps: the #GstCaps to truncate
846 * Destructively discard all but the first structure from @caps. Useful when
847 * fixating. @caps must be writable.
850 gst_caps_truncate (GstCaps * caps)
854 g_return_if_fail (GST_IS_CAPS (caps));
855 g_return_if_fail (IS_WRITABLE (caps));
857 i = caps->structs->len - 1;
860 gst_caps_remove_structure (caps, i--);
864 * gst_caps_set_simple:
865 * @caps: the #GstCaps to set
866 * @field: first field to set
867 * @...: additional parameters
869 * Sets fields in a simple #GstCaps. A simple #GstCaps is one that
870 * only has one structure. The arguments must be passed in the same
871 * manner as gst_structure_set(), and be NULL-terminated.
874 gst_caps_set_simple (GstCaps * caps, const char *field, ...)
876 GstStructure *structure;
879 g_return_if_fail (GST_IS_CAPS (caps));
880 g_return_if_fail (caps->structs->len == 1);
881 g_return_if_fail (IS_WRITABLE (caps));
883 structure = gst_caps_get_structure_unchecked (caps, 0);
885 va_start (var_args, field);
886 gst_structure_set_valist (structure, field, var_args);
891 * gst_caps_set_simple_valist:
892 * @caps: the #GstCaps to copy
893 * @field: first field to set
894 * @varargs: additional parameters
896 * Sets fields in a simple #GstCaps. A simple #GstCaps is one that
897 * only has one structure. The arguments must be passed in the same
898 * manner as gst_structure_set(), and be NULL-terminated.
901 gst_caps_set_simple_valist (GstCaps * caps, const char *field, va_list varargs)
903 GstStructure *structure;
905 g_return_if_fail (GST_IS_CAPS (caps));
906 g_return_if_fail (caps->structs->len == 1);
907 g_return_if_fail (IS_WRITABLE (caps));
909 structure = gst_caps_get_structure_unchecked (caps, 0);
911 gst_structure_set_valist (structure, field, varargs);
918 * @caps: the #GstCaps to test
920 * Determines if @caps represents any media format.
922 * Returns: TRUE if @caps represents any format.
925 gst_caps_is_any (const GstCaps * caps)
927 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
929 return (caps->flags & GST_CAPS_FLAGS_ANY);
934 * @caps: the #GstCaps to test
936 * Determines if @caps represents no media formats.
938 * Returns: TRUE if @caps represents no formats.
941 gst_caps_is_empty (const GstCaps * caps)
943 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
945 if (caps->flags & GST_CAPS_FLAGS_ANY)
948 return (caps->structs == NULL) || (caps->structs->len == 0);
952 gst_caps_is_fixed_foreach (GQuark field_id, const GValue * value,
955 return gst_value_is_fixed (value);
960 * @caps: the #GstCaps to test
962 * Fixed #GstCaps describe exactly one format, that is, they have exactly
963 * one structure, and each field in the structure describes a fixed type.
964 * Examples of non-fixed types are GST_TYPE_INT_RANGE and GST_TYPE_LIST.
966 * Returns: TRUE if @caps is fixed
969 gst_caps_is_fixed (const GstCaps * caps)
971 GstStructure *structure;
973 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
975 if (caps->structs->len != 1)
978 structure = gst_caps_get_structure_unchecked (caps, 0);
980 return gst_structure_foreach (structure, gst_caps_is_fixed_foreach, NULL);
984 * gst_caps_is_equal_fixed:
985 * @caps1: the #GstCaps to test
986 * @caps2: the #GstCaps to test
988 * Tests if two #GstCaps are equal. This function only works on fixed
991 * Returns: TRUE if the arguments represent the same format
994 gst_caps_is_equal_fixed (const GstCaps * caps1, const GstCaps * caps2)
996 GstStructure *struct1, *struct2;
998 g_return_val_if_fail (gst_caps_is_fixed (caps1), FALSE);
999 g_return_val_if_fail (gst_caps_is_fixed (caps2), FALSE);
1001 struct1 = gst_caps_get_structure_unchecked (caps1, 0);
1002 struct2 = gst_caps_get_structure_unchecked (caps2, 0);
1004 if (struct1->name != struct2->name) {
1007 if (struct1->fields->len != struct2->fields->len) {
1011 return gst_structure_foreach (struct1, gst_structure_is_equal_foreach,
1016 * gst_caps_is_always_compatible:
1017 * @caps1: the #GstCaps to test
1018 * @caps2: the #GstCaps to test
1020 * A given #GstCaps structure is always compatible with another if
1021 * every media format that is in the first is also contained in the
1022 * second. That is, @caps1 is a subset of @caps2.
1024 * Returns: TRUE if @caps1 is a subset of @caps2.
1027 gst_caps_is_always_compatible (const GstCaps * caps1, const GstCaps * caps2)
1029 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1030 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1032 return gst_caps_is_subset (caps1, caps2);
1036 * gst_caps_is_subset:
1037 * @subset: a #GstCaps
1038 * @superset: a potentially greater #GstCaps
1040 * Checks if all caps represented by @subset are also represented by @superset.
1041 * <note>This function does not work reliably if optional properties for caps
1042 * are included on one caps and omitted on the other.</note>
1044 * Returns: %TRUE if @subset is a subset of @superset
1047 gst_caps_is_subset (const GstCaps * subset, const GstCaps * superset)
1052 g_return_val_if_fail (subset != NULL, FALSE);
1053 g_return_val_if_fail (superset != NULL, FALSE);
1055 if (gst_caps_is_empty (subset) || gst_caps_is_any (superset))
1057 if (gst_caps_is_any (subset) || gst_caps_is_empty (superset))
1060 caps = gst_caps_subtract (subset, superset);
1061 ret = gst_caps_is_empty (caps);
1062 gst_caps_unref (caps);
1067 * gst_caps_is_equal:
1068 * @caps1: a #GstCaps
1069 * @caps2: another #GstCaps
1071 * Checks if the given caps represent the same set of caps.
1072 * <note>This function does not work reliably if optional properties for caps
1073 * are included on one caps and omitted on the other.</note>
1075 * This function deals correctly with passing NULL for any of the caps.
1077 * Returns: TRUE if both caps are equal.
1080 gst_caps_is_equal (const GstCaps * caps1, const GstCaps * caps2)
1082 /* FIXME 0.11: NULL pointers are no valid Caps but indicate an error
1083 * So there should be an assertion that caps1 and caps2 != NULL */
1085 /* NULL <-> NULL is allowed here */
1089 /* one of them NULL => they are different (can't be both NULL because
1090 * we checked that above) */
1091 if (caps1 == NULL || caps2 == NULL)
1094 if (gst_caps_is_fixed (caps1) && gst_caps_is_fixed (caps2))
1095 return gst_caps_is_equal_fixed (caps1, caps2);
1097 return gst_caps_is_subset (caps1, caps2) && gst_caps_is_subset (caps2, caps1);
1103 const GstStructure *intersect;
1109 gst_caps_structure_intersect_field (GQuark id, const GValue * val1,
1112 IntersectData *idata = (IntersectData *) data;
1113 GValue dest_value = { 0 };
1114 const GValue *val2 = gst_structure_id_get_value (idata->intersect, id);
1117 gst_structure_id_set_value (idata->dest, id, val1);
1118 } else if (idata->first_run) {
1119 if (gst_value_intersect (&dest_value, val1, val2)) {
1120 gst_structure_id_set_value (idata->dest, id, &dest_value);
1121 g_value_unset (&dest_value);
1130 static GstStructure *
1131 gst_caps_structure_intersect (const GstStructure * struct1,
1132 const GstStructure * struct2)
1136 g_return_val_if_fail (struct1 != NULL, NULL);
1137 g_return_val_if_fail (struct2 != NULL, NULL);
1139 if (struct1->name != struct2->name)
1142 data.dest = gst_structure_id_empty_new (struct1->name);
1143 data.intersect = struct2;
1144 data.first_run = TRUE;
1145 if (!gst_structure_foreach ((GstStructure *) struct1,
1146 gst_caps_structure_intersect_field, &data))
1149 data.intersect = struct1;
1150 data.first_run = FALSE;
1151 if (!gst_structure_foreach ((GstStructure *) struct2,
1152 gst_caps_structure_intersect_field, &data))
1158 gst_structure_free (data.dest);
1163 static GstStructure *
1164 gst_caps_structure_union (const GstStructure * struct1,
1165 const GstStructure * struct2)
1169 const GstStructureField *field1;
1170 const GstStructureField *field2;
1173 /* FIXME this doesn't actually work */
1175 if (struct1->name != struct2->name)
1178 dest = gst_structure_id_empty_new (struct1->name);
1180 for (i = 0; i < struct1->fields->len; i++) {
1181 GValue dest_value = { 0 };
1183 field1 = GST_STRUCTURE_FIELD (struct1, i);
1184 field2 = gst_structure_id_get_field (struct2, field1->name);
1186 if (field2 == NULL) {
1189 if (gst_value_union (&dest_value, &field1->value, &field2->value)) {
1190 gst_structure_set_value (dest, g_quark_to_string (field1->name),
1193 ret = gst_value_compare (&field1->value, &field2->value);
1205 * gst_caps_intersect:
1206 * @caps1: a #GstCaps to intersect
1207 * @caps2: a #GstCaps to intersect
1209 * Creates a new #GstCaps that contains all the formats that are common
1210 * to both @caps1 and @caps2.
1212 * Returns: the new #GstCaps
1215 gst_caps_intersect (const GstCaps * caps1, const GstCaps * caps2)
1217 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1218 guint j, k, len1, len2;
1220 GstStructure *struct1;
1221 GstStructure *struct2;
1223 GstStructure *istruct;
1225 g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
1226 g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
1228 /* caps are exactly the same pointers, just copy one caps */
1230 return gst_caps_copy (caps1);
1232 /* empty caps on either side, return empty */
1233 if (gst_caps_is_empty (caps1) || gst_caps_is_empty (caps2))
1234 return gst_caps_new_empty ();
1236 /* one of the caps is any, just copy the other caps */
1237 if (gst_caps_is_any (caps1))
1238 return gst_caps_copy (caps2);
1239 if (gst_caps_is_any (caps2))
1240 return gst_caps_copy (caps1);
1242 dest = gst_caps_new_empty ();
1244 /* run zigzag on top line then right line, this preserves the caps order
1245 * much better than a simple loop.
1247 * This algorithm zigzags over the caps structures as demonstrated in
1248 * the folowing matrix:
1256 * First we iterate over the caps1 structures (top line) intersecting
1257 * the structures diagonally down, then we iterate over the caps2
1260 len1 = caps1->structs->len;
1261 len2 = caps2->structs->len;
1262 for (i = 0; i < len1 + len2 - 1; i++) {
1263 /* caps1 index goes from 0 to caps1->structs->len-1 */
1264 j = MIN (i, len1 - 1);
1265 /* caps2 index stays 0 until i reaches caps1->structs->len, then it counts
1266 * up from 1 to caps2->structs->len - 1 */
1269 /* now run the diagonal line, end condition is the left or bottom
1272 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1273 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1275 istruct = gst_caps_structure_intersect (struct1, struct2);
1277 gst_caps_append_structure (dest, istruct);
1278 /* move down left */
1281 break; /* so we don't roll back to G_MAXUINT */
1290 const GstStructure *subtract_from;
1297 gst_caps_structure_subtract_field (GQuark field_id, const GValue * value,
1300 SubtractionEntry *e = user_data;
1301 GValue subtraction = { 0, };
1302 const GValue *other;
1303 GstStructure *structure;
1305 other = gst_structure_id_get_value (e->subtract_from, field_id);
1309 if (!gst_value_subtract (&subtraction, other, value))
1311 if (gst_value_compare (&subtraction, other) == GST_VALUE_EQUAL) {
1312 g_value_unset (&subtraction);
1315 structure = gst_structure_copy (e->subtract_from);
1316 gst_structure_id_set_value (structure, field_id, &subtraction);
1317 g_value_unset (&subtraction);
1318 e->put_into = g_slist_prepend (e->put_into, structure);
1324 gst_caps_structure_subtract (GSList ** into, const GstStructure * minuend,
1325 const GstStructure * subtrahend)
1330 e.subtract_from = minuend;
1333 ret = gst_structure_foreach ((GstStructure *) subtrahend,
1334 gst_caps_structure_subtract_field, &e);
1340 for (walk = e.put_into; walk; walk = g_slist_next (walk)) {
1341 gst_structure_free (walk->data);
1343 g_slist_free (e.put_into);
1349 * gst_caps_subtract:
1350 * @minuend: #GstCaps to substract from
1351 * @subtrahend: #GstCaps to substract
1353 * Subtracts the @subtrahend from the @minuend.
1354 * <note>This function does not work reliably if optional properties for caps
1355 * are included on one caps and omitted on the other.</note>
1357 * Returns: the resulting caps
1360 gst_caps_subtract (const GstCaps * minuend, const GstCaps * subtrahend)
1365 GstCaps *dest = NULL, *src;
1367 g_return_val_if_fail (minuend != NULL, NULL);
1368 g_return_val_if_fail (subtrahend != NULL, NULL);
1370 if (gst_caps_is_empty (minuend) || gst_caps_is_any (subtrahend)) {
1371 return gst_caps_new_empty ();
1373 if (gst_caps_is_empty (subtrahend))
1374 return gst_caps_copy (minuend);
1376 /* FIXME: Do we want this here or above?
1377 The reason we need this is that there is no definition about what
1378 ANY means for specific types, so it's not possible to reduce ANY partially
1379 You can only remove everything or nothing and that is done above.
1380 Note: there's a test that checks this behaviour. */
1381 g_return_val_if_fail (!gst_caps_is_any (minuend), NULL);
1382 sublen = subtrahend->structs->len;
1383 g_assert (sublen > 0);
1385 src = gst_caps_copy (minuend);
1386 for (i = 0; i < sublen; i++) {
1389 sub = gst_caps_get_structure_unchecked (subtrahend, i);
1391 gst_caps_unref (src);
1394 dest = gst_caps_new_empty ();
1395 srclen = src->structs->len;
1396 for (j = 0; j < srclen; j++) {
1397 min = gst_caps_get_structure_unchecked (src, j);
1398 if (gst_structure_get_name_id (min) == gst_structure_get_name_id (sub)) {
1401 if (gst_caps_structure_subtract (&list, min, sub)) {
1404 for (walk = list; walk; walk = g_slist_next (walk)) {
1405 gst_caps_append_structure (dest, (GstStructure *) walk->data);
1407 g_slist_free (list);
1409 gst_caps_append_structure (dest, gst_structure_copy (min));
1412 gst_caps_append_structure (dest, gst_structure_copy (min));
1415 if (gst_caps_is_empty (dest)) {
1416 gst_caps_unref (src);
1421 gst_caps_unref (src);
1422 gst_caps_do_simplify (dest);
1428 * @caps1: a #GstCaps to union
1429 * @caps2: a #GstCaps to union
1431 * Creates a new #GstCaps that contains all the formats that are in
1432 * either @caps1 and @caps2.
1434 * Returns: the new #GstCaps
1437 gst_caps_union (const GstCaps * caps1, const GstCaps * caps2)
1442 /* NULL pointers are no correct GstCaps */
1443 g_return_val_if_fail (caps1 != NULL, NULL);
1444 g_return_val_if_fail (caps2 != NULL, NULL);
1446 if (gst_caps_is_empty (caps1))
1447 return gst_caps_copy (caps2);
1449 if (gst_caps_is_empty (caps2))
1450 return gst_caps_copy (caps1);
1452 if (gst_caps_is_any (caps1) || gst_caps_is_any (caps2))
1453 return gst_caps_new_any ();
1455 dest1 = gst_caps_copy (caps1);
1456 dest2 = gst_caps_copy (caps2);
1457 gst_caps_append (dest1, dest2);
1459 gst_caps_do_simplify (dest1);
1463 typedef struct _NormalizeForeach
1466 GstStructure *structure;
1471 gst_caps_normalize_foreach (GQuark field_id, const GValue * value, gpointer ptr)
1473 NormalizeForeach *nf = (NormalizeForeach *) ptr;
1477 if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
1478 guint len = gst_value_list_get_size (value);
1479 for (i = 1; i < len; i++) {
1480 const GValue *v = gst_value_list_get_value (value, i);
1481 GstStructure *structure = gst_structure_copy (nf->structure);
1483 gst_structure_id_set_value (structure, field_id, v);
1484 gst_caps_append_structure (nf->caps, structure);
1487 gst_value_init_and_copy (&val, gst_value_list_get_value (value, 0));
1488 gst_structure_id_set_value (nf->structure, field_id, &val);
1489 g_value_unset (&val);
1497 * gst_caps_normalize:
1498 * @caps: a #GstCaps to normalize
1500 * Creates a new #GstCaps that represents the same set of formats as
1501 * @caps, but contains no lists. Each list is expanded into separate
1504 * Returns: the new #GstCaps
1507 gst_caps_normalize (const GstCaps * caps)
1509 NormalizeForeach nf;
1513 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
1515 newcaps = gst_caps_copy (caps);
1517 nlen = newcaps->structs->len;
1519 for (i = 0; i < nlen; i++) {
1520 nf.structure = gst_caps_get_structure_unchecked (newcaps, i);
1522 while (!gst_structure_foreach (nf.structure,
1523 gst_caps_normalize_foreach, &nf));
1530 gst_caps_compare_structures (gconstpointer one, gconstpointer two)
1533 const GstStructure *struct1 = *((const GstStructure **) one);
1534 const GstStructure *struct2 = *((const GstStructure **) two);
1536 /* FIXME: this orders alphabetically, but ordering the quarks might be faster
1537 So what's the best way? */
1538 ret = strcmp (gst_structure_get_name (struct1),
1539 gst_structure_get_name (struct2));
1543 return gst_structure_n_fields (struct2) - gst_structure_n_fields (struct1);
1550 GstStructure *compare;
1555 gst_caps_structure_figure_out_union (GQuark field_id, const GValue * value,
1558 UnionField *u = user_data;
1559 const GValue *val = gst_structure_id_get_value (u->compare, field_id);
1563 g_value_unset (&u->value);
1566 if (gst_value_compare (val, value) == GST_VALUE_EQUAL)
1569 g_value_unset (&u->value);
1573 gst_value_union (&u->value, val, value);
1578 gst_caps_structure_simplify (GstStructure ** result,
1579 const GstStructure * simplify, GstStructure * compare)
1582 UnionField field = { 0, {0,}, NULL };
1584 /* try to subtract to get a real subset */
1585 if (gst_caps_structure_subtract (&list, simplify, compare)) {
1586 switch (g_slist_length (list)) {
1591 *result = list->data;
1592 g_slist_free (list);
1598 for (walk = list; walk; walk = g_slist_next (walk)) {
1599 gst_structure_free (walk->data);
1601 g_slist_free (list);
1607 /* try to union both structs */
1608 field.compare = compare;
1609 if (gst_structure_foreach ((GstStructure *) simplify,
1610 gst_caps_structure_figure_out_union, &field)) {
1611 gboolean ret = FALSE;
1613 /* now we know all of simplify's fields are the same in compare
1614 * but at most one field: field.name */
1615 if (G_IS_VALUE (&field.value)) {
1616 if (gst_structure_n_fields (simplify) == gst_structure_n_fields (compare)) {
1617 gst_structure_id_set_value (compare, field.name, &field.value);
1621 g_value_unset (&field.value);
1622 } else if (gst_structure_n_fields (simplify) <=
1623 gst_structure_n_fields (compare)) {
1624 /* compare is just more specific, will be optimized away later */
1625 /* FIXME: do this here? */
1626 GST_LOG ("found a case that will be optimized later.");
1628 gchar *one = gst_structure_to_string (simplify);
1629 gchar *two = gst_structure_to_string (compare);
1632 ("caps mismatch: structures %s and %s claim to be possible to unify, but aren't",
1644 gst_caps_switch_structures (GstCaps * caps, GstStructure * old,
1645 GstStructure * new, gint i)
1647 gst_structure_set_parent_refcount (old, NULL);
1648 gst_structure_free (old);
1649 gst_structure_set_parent_refcount (new, &caps->refcount);
1650 g_ptr_array_index (caps->structs, i) = new;
1654 * gst_caps_do_simplify:
1655 * @caps: a #GstCaps to simplify
1657 * Modifies the given @caps inplace into a representation that represents the
1658 * same set of formats, but in a simpler form. Component structures that are
1659 * identical are merged. Component structures that have values that can be
1660 * merged are also merged.
1662 * Returns: TRUE, if the caps could be simplified
1665 gst_caps_do_simplify (GstCaps * caps)
1667 GstStructure *simplify, *compare, *result = NULL;
1669 gboolean changed = FALSE;
1671 g_return_val_if_fail (caps != NULL, FALSE);
1672 g_return_val_if_fail (IS_WRITABLE (caps), FALSE);
1674 if (gst_caps_get_size (caps) < 2)
1677 g_ptr_array_sort (caps->structs, gst_caps_compare_structures);
1679 start = caps->structs->len - 1;
1680 for (i = caps->structs->len - 1; i >= 0; i--) {
1681 simplify = gst_caps_get_structure_unchecked (caps, i);
1682 if (gst_structure_get_name_id (simplify) !=
1683 gst_structure_get_name_id (gst_caps_get_structure_unchecked (caps,
1686 for (j = start; j >= 0; j--) {
1689 compare = gst_caps_get_structure_unchecked (caps, j);
1690 if (gst_structure_get_name_id (simplify) !=
1691 gst_structure_get_name_id (compare)) {
1694 if (gst_caps_structure_simplify (&result, simplify, compare)) {
1696 gst_caps_switch_structures (caps, simplify, result, i);
1699 gst_caps_remove_structure (caps, i);
1711 /* gst_caps_do_simplify (caps); */
1715 #ifndef GST_DISABLE_LOADSAVE
1717 * gst_caps_save_thyself:
1718 * @caps: a #GstCaps structure
1719 * @parent: a XML parent node
1721 * Serializes a #GstCaps to XML and adds it as a child node of @parent.
1723 * Returns: a XML node pointer
1726 gst_caps_save_thyself (const GstCaps * caps, xmlNodePtr parent)
1728 char *s = gst_caps_to_string (caps);
1730 xmlNewChild (parent, NULL, (xmlChar *) "caps", (xmlChar *) s);
1736 * gst_caps_load_thyself:
1737 * @parent: a XML node
1739 * Creates a #GstCaps from its XML serialization.
1741 * Returns: a new #GstCaps structure
1744 gst_caps_load_thyself (xmlNodePtr parent)
1746 if (strcmp ("caps", (char *) parent->name) == 0) {
1747 return gst_caps_from_string ((gchar *) xmlNodeGetContent (parent));
1758 * @caps: a pointer to #GstCaps
1759 * @newcaps: a #GstCaps to replace *caps
1761 * Replaces *caps with @newcaps. Unrefs the #GstCaps in the location
1762 * pointed to by @caps, if applicable, then modifies @caps to point to
1763 * @newcaps. An additional ref on @newcaps is taken.
1765 * This function does not take any locks so you might want to lock
1766 * the object owning @caps pointer.
1769 gst_caps_replace (GstCaps ** caps, GstCaps * newcaps)
1773 g_return_if_fail (caps != NULL);
1777 if (newcaps != oldcaps) {
1779 gst_caps_ref (newcaps);
1784 gst_caps_unref (oldcaps);
1789 * gst_caps_to_string:
1792 * Converts @caps to a string representation. This string representation
1793 * can be converted back to a #GstCaps by gst_caps_from_string().
1795 * For debugging purposes its easier to do something like this:
1797 * GST_LOG ("caps are %" GST_PTR_FORMAT, caps);
1799 * This prints the caps in human readble form.
1801 * Returns: a newly allocated string representing @caps.
1804 gst_caps_to_string (const GstCaps * caps)
1806 guint i, slen, clen;
1809 /* NOTE: This function is potentially called by the debug system,
1810 * so any calls to gst_log() (and GST_DEBUG(), GST_LOG(), etc.)
1811 * should be careful to avoid recursion. This includes any functions
1812 * called by gst_caps_to_string. In particular, calls should
1813 * not use the GST_PTR_FORMAT extension. */
1816 return g_strdup ("NULL");
1818 if (gst_caps_is_any (caps)) {
1819 return g_strdup ("ANY");
1821 if (gst_caps_is_empty (caps)) {
1822 return g_strdup ("EMPTY");
1825 /* estimate a rough string length to avoid unnecessary reallocs in GString */
1827 clen = caps->structs->len;
1828 for (i = 0; i < clen; i++) {
1830 STRUCTURE_ESTIMATED_STRING_LEN (gst_caps_get_structure_unchecked (caps,
1834 s = g_string_sized_new (slen);
1835 for (i = 0; i < clen; i++) {
1836 GstStructure *structure;
1839 /* ';' is now added by gst_structure_to_string */
1840 g_string_append_c (s, ' ');
1843 structure = gst_caps_get_structure_unchecked (caps, i);
1844 priv_gst_structure_append_to_gstring (structure, s);
1846 if (s->len && s->str[s->len - 1] == ';') {
1847 /* remove latest ';' */
1848 s->str[--s->len] = '\0';
1850 return g_string_free (s, FALSE);
1854 gst_caps_from_string_inplace (GstCaps * caps, const gchar * string)
1856 GstStructure *structure;
1859 g_return_val_if_fail (string, FALSE);
1860 if (strcmp ("ANY", string) == 0) {
1861 caps->flags = GST_CAPS_FLAGS_ANY;
1864 if (strcmp ("EMPTY", string) == 0) {
1868 structure = gst_structure_from_string (string, &s);
1869 if (structure == NULL) {
1872 gst_caps_append_structure (caps, structure);
1876 while (g_ascii_isspace (*s))
1881 structure = gst_structure_from_string (s, &s);
1882 if (structure == NULL) {
1885 gst_caps_append_structure (caps, structure);
1893 * gst_caps_from_string:
1894 * @string: a string to convert to #GstCaps
1896 * Converts @caps from a string representation.
1898 * Returns: a newly allocated #GstCaps
1901 gst_caps_from_string (const gchar * string)
1905 caps = gst_caps_new_empty ();
1906 if (gst_caps_from_string_inplace (caps, string)) {
1909 gst_caps_unref (caps);
1915 gst_caps_transform_to_string (const GValue * src_value, GValue * dest_value)
1917 g_return_if_fail (G_IS_VALUE (src_value));
1918 g_return_if_fail (G_IS_VALUE (dest_value));
1919 g_return_if_fail (G_VALUE_HOLDS (src_value, GST_TYPE_CAPS));
1920 g_return_if_fail (G_VALUE_HOLDS (dest_value, G_TYPE_STRING)
1921 || G_VALUE_HOLDS (dest_value, G_TYPE_POINTER));
1923 dest_value->data[0].v_pointer =
1924 gst_caps_to_string (src_value->data[0].v_pointer);
1928 gst_caps_copy_conditional (GstCaps * src)
1931 return gst_caps_ref (src);