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 ();
146 /* the 32 has been determined by logging caps sizes in _gst_caps_free
147 * but g_ptr_array uses 16 anyway if it expands once, so this does not help
149 * caps->structs = g_ptr_array_sized_new (32);
152 #ifdef DEBUG_REFCOUNT
153 GST_CAT_LOG (GST_CAT_CAPS, "created caps %p", caps);
162 * Creates a new #GstCaps that indicates that it is compatible with
165 * Returns: the new #GstCaps
168 gst_caps_new_any (void)
170 GstCaps *caps = gst_caps_new_empty ();
172 caps->flags = GST_CAPS_FLAGS_ANY;
178 * gst_caps_new_simple:
179 * @media_type: the media type of the structure
180 * @fieldname: first field to set
181 * @...: additional arguments
183 * Creates a new #GstCaps that contains one #GstStructure. The
184 * structure is defined by the arguments, which have the same format
185 * as gst_structure_new().
186 * Caller is responsible for unreffing the returned caps.
188 * Returns: the new #GstCaps
191 gst_caps_new_simple (const char *media_type, const char *fieldname, ...)
194 GstStructure *structure;
197 caps = gst_caps_new_empty ();
199 va_start (var_args, fieldname);
200 structure = gst_structure_new_valist (media_type, fieldname, var_args);
203 gst_caps_append_structure (caps, structure);
210 * @struct1: the first structure to add
211 * @...: additional structures to add
213 * Creates a new #GstCaps and adds all the structures listed as
214 * arguments. The list must be NULL-terminated. The structures
215 * are not copied; the returned #GstCaps owns the structures.
217 * Returns: the new #GstCaps
220 gst_caps_new_full (GstStructure * struct1, ...)
225 va_start (var_args, struct1);
226 caps = gst_caps_new_full_valist (struct1, var_args);
233 * gst_caps_new_full_valist:
234 * @structure: the first structure to add
235 * @var_args: additional structures to add
237 * Creates a new #GstCaps and adds all the structures listed as
238 * arguments. The list must be NULL-terminated. The structures
239 * are not copied; the returned #GstCaps owns the structures.
241 * Returns: the new #GstCaps
244 gst_caps_new_full_valist (GstStructure * structure, va_list var_args)
248 caps = gst_caps_new_empty ();
251 gst_caps_append_structure (caps, structure);
252 structure = va_arg (var_args, GstStructure *);
260 * @caps: the #GstCaps to copy
262 * Creates a new #GstCaps as a copy of the old @caps. The new caps will have a
263 * refcount of 1, owned by the caller. The structures are copied as well.
265 * Note that this function is the semantic equivalent of a gst_caps_ref()
266 * followed by a gst_caps_make_writable(). If you only want to hold on to a
267 * reference to the data, you should use gst_caps_ref().
269 * When you are finished with the caps, call gst_caps_unref() on it.
271 * Returns: the new #GstCaps
274 gst_caps_copy (const GstCaps * caps)
277 GstStructure *structure;
280 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
282 newcaps = gst_caps_new_empty ();
283 newcaps->flags = caps->flags;
284 n = caps->structs->len;
286 for (i = 0; i < n; i++) {
287 structure = gst_caps_get_structure_unchecked (caps, i);
288 gst_caps_append_structure (newcaps, gst_structure_copy (structure));
295 _gst_caps_free (GstCaps * caps)
297 GstStructure *structure;
300 /* The refcount must be 0, but since we're only called by gst_caps_unref,
301 * don't bother testing. */
302 len = caps->structs->len;
303 /* This can be used to get statistics about caps sizes */
304 /*GST_CAT_INFO (GST_CAT_CAPS, "caps size: %d", len); */
305 for (i = 0; i < len; i++) {
306 structure = (GstStructure *) gst_caps_get_structure_unchecked (caps, i);
307 gst_structure_set_parent_refcount (structure, NULL);
308 gst_structure_free (structure);
310 g_ptr_array_free (caps->structs, TRUE);
312 memset (caps, 0xff, sizeof (GstCaps));
315 #ifdef DEBUG_REFCOUNT
316 GST_CAT_LOG (GST_CAT_CAPS, "freeing caps %p", caps);
318 g_slice_free (GstCaps, caps);
322 * gst_caps_make_writable:
323 * @caps: the #GstCaps to make writable
325 * Returns a writable copy of @caps.
327 * If there is only one reference count on @caps, the caller must be the owner,
328 * and so this function will return the caps object unchanged. If on the other
329 * hand there is more than one reference on the object, a new caps object will
330 * be returned. The caller's reference on @caps will be removed, and instead the
331 * caller will own a reference to the returned object.
333 * In short, this function unrefs the caps in the argument and refs the caps
334 * that it returns. Don't access the argument after calling this function. See
335 * also: gst_caps_ref().
337 * Returns: the same #GstCaps object.
340 gst_caps_make_writable (GstCaps * caps)
344 g_return_val_if_fail (caps != NULL, NULL);
346 /* we are the only instance reffing this caps */
347 if (g_atomic_int_get (&caps->refcount) == 1)
351 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy caps");
352 copy = gst_caps_copy (caps);
353 gst_caps_unref (caps);
360 * @caps: the #GstCaps to reference
362 * Add a reference to a #GstCaps object.
364 * From this point on, until the caller calls gst_caps_unref() or
365 * gst_caps_make_writable(), it is guaranteed that the caps object will not
366 * change. This means its structures won't change, etc. To use a #GstCaps
367 * object, you must always have a refcount on it -- either the one made
368 * implicitly by gst_caps_new(), or via taking one explicitly with this
371 * Returns: the same #GstCaps object.
374 gst_caps_ref (GstCaps * caps)
376 g_return_val_if_fail (caps != NULL, NULL);
378 #ifdef DEBUG_REFCOUNT
379 GST_CAT_LOG (GST_CAT_REFCOUNTING, "%p %d->%d", caps,
380 GST_CAPS_REFCOUNT_VALUE (caps), GST_CAPS_REFCOUNT_VALUE (caps) + 1);
382 g_return_val_if_fail (GST_CAPS_REFCOUNT_VALUE (caps) > 0, NULL);
384 g_atomic_int_inc (&caps->refcount);
391 * @caps: the #GstCaps to unref
393 * Unref a #GstCaps and and free all its structures and the
394 * structures' values when the refcount reaches 0.
397 gst_caps_unref (GstCaps * caps)
399 g_return_if_fail (caps != NULL);
401 #ifdef DEBUG_REFCOUNT
402 GST_CAT_LOG (GST_CAT_REFCOUNTING, "%p %d->%d", caps,
403 GST_CAPS_REFCOUNT_VALUE (caps), GST_CAPS_REFCOUNT_VALUE (caps) - 1);
406 g_return_if_fail (GST_CAPS_REFCOUNT_VALUE (caps) > 0);
408 /* if we ended up with the refcount at zero, free the caps */
409 if (G_UNLIKELY (g_atomic_int_dec_and_test (&caps->refcount)))
410 _gst_caps_free (caps);
414 gst_static_caps_get_type (void)
416 static GType staticcaps_type = 0;
418 if (G_UNLIKELY (staticcaps_type == 0)) {
419 staticcaps_type = g_pointer_type_register_static ("GstStaticCaps");
421 return staticcaps_type;
426 * gst_static_caps_get:
427 * @static_caps: the #GstStaticCaps to convert
429 * Converts a #GstStaticCaps to a #GstCaps.
431 * Returns: A pointer to the #GstCaps. Unref after usage. Since the
432 * core holds an additional ref to the returned caps,
433 * use gst_caps_make_writable() on the returned caps to modify it.
436 gst_static_caps_get (GstStaticCaps * static_caps)
440 g_return_val_if_fail (static_caps != NULL, NULL);
442 caps = (GstCaps *) static_caps;
444 /* refcount is 0 when we need to convert */
445 if (G_UNLIKELY (g_atomic_int_get (&caps->refcount) == 0)) {
449 G_LOCK (static_caps_lock);
450 /* check if other thread already updated */
451 if (G_UNLIKELY (g_atomic_int_get (&caps->refcount) > 0))
454 string = static_caps->string;
456 if (G_UNLIKELY (string == NULL))
459 GST_CAT_LOG (GST_CAT_CAPS, "creating %p", static_caps);
461 /* we construct the caps on the stack, then copy over the struct into our
462 * real caps, refcount last. We do this because we must leave the refcount
463 * of the result caps to 0 so that other threads don't run away with the
464 * caps while we are constructing it. */
465 temp.type = GST_TYPE_CAPS;
467 temp.structs = g_ptr_array_new ();
469 /* initialize the caps to a refcount of 1 so the caps can be writable for
470 * the next statement */
473 /* convert to string */
474 if (G_UNLIKELY (!gst_caps_from_string_inplace (&temp, string)))
475 g_critical ("Could not convert static caps \"%s\"", string);
477 /* now copy stuff over to the real caps. */
478 caps->type = temp.type;
479 caps->flags = temp.flags;
480 caps->structs = temp.structs;
481 /* and bump the refcount so other threads can now read */
482 g_atomic_int_set (&caps->refcount, 1);
484 GST_CAT_LOG (GST_CAT_CAPS, "created %p", static_caps);
486 G_UNLOCK (static_caps_lock);
488 /* ref the caps, makes it not writable */
496 G_UNLOCK (static_caps_lock);
497 g_warning ("static caps %p string is NULL", static_caps);
503 static GstStructure *
504 gst_caps_remove_and_get_structure (GstCaps * caps, guint idx)
506 /* don't use index_fast, gst_caps_do_simplify relies on the order */
507 GstStructure *s = g_ptr_array_remove_index (caps->structs, idx);
509 gst_structure_set_parent_refcount (s, NULL);
514 gst_structure_is_equal_foreach (GQuark field_id, const GValue * val2,
517 GstStructure *struct1 = (GstStructure *) data;
518 const GValue *val1 = gst_structure_id_get_value (struct1, field_id);
520 if (G_UNLIKELY (val1 == NULL))
522 if (gst_value_compare (val1, val2) == GST_VALUE_EQUAL) {
530 gst_caps_structure_is_subset_field (GQuark field_id, const GValue * value,
533 GstStructure *subtract_from = user_data;
534 GValue subtraction = { 0, };
537 if (!(other = gst_structure_id_get_value (subtract_from, field_id)))
538 /* field is missing in one set */
541 /* equal values are subset */
542 if (gst_value_compare (other, value) == GST_VALUE_EQUAL)
550 * -> 1 - [1,2] = empty
554 * -> [1,2] - [1,3] = empty
558 * -> {1,3} - {1,2} = 3
561 * First caps subtraction needs to return a non-empty set, second
562 * subtractions needs to give en empty set.
564 if (gst_value_subtract (&subtraction, other, value)) {
565 g_value_unset (&subtraction);
566 /* !empty result, swapping must be empty */
567 if (!gst_value_subtract (&subtraction, value, other))
570 g_value_unset (&subtraction);
576 gst_caps_structure_is_subset (const GstStructure * minuend,
577 const GstStructure * subtrahend)
579 if ((minuend->name != subtrahend->name) ||
580 (gst_structure_n_fields (minuend) !=
581 gst_structure_n_fields (subtrahend))) {
585 return gst_structure_foreach ((GstStructure *) subtrahend,
586 gst_caps_structure_is_subset_field, (gpointer) minuend);
591 * @caps1: the #GstCaps that will be appended to
592 * @caps2: the #GstCaps to append
594 * Appends the structures contained in @caps2 to @caps1. The structures in
595 * @caps2 are not copied -- they are transferred to @caps1, and then @caps2 is
596 * freed. If either caps is ANY, the resulting caps will be ANY.
599 gst_caps_append (GstCaps * caps1, GstCaps * caps2)
601 GstStructure *structure;
604 g_return_if_fail (GST_IS_CAPS (caps1));
605 g_return_if_fail (GST_IS_CAPS (caps2));
606 g_return_if_fail (IS_WRITABLE (caps1));
607 g_return_if_fail (IS_WRITABLE (caps2));
612 if (G_UNLIKELY (gst_caps_is_any (caps1) || gst_caps_is_any (caps2))) {
613 /* FIXME: this leaks */
614 caps1->flags |= GST_CAPS_FLAGS_ANY;
615 for (i = caps2->structs->len - 1; i >= 0; i--) {
616 structure = gst_caps_remove_and_get_structure (caps2, i);
617 gst_structure_free (structure);
620 for (i = caps2->structs->len; i; i--) {
621 structure = gst_caps_remove_and_get_structure (caps2, 0);
622 gst_caps_append_structure (caps1, structure);
625 gst_caps_unref (caps2); /* guaranteed to free it */
630 * @caps1: the #GstCaps that will take the new entries
631 * @caps2: the #GstCaps to merge in
633 * Appends the structures contained in @caps2 to @caps1 if they are not yet
634 * expressed by @caps1. The structures in @caps2 are not copied -- they are
635 * transferred to @caps1, and then @caps2 is freed.
636 * If either caps is ANY, the resulting caps will be ANY.
641 gst_caps_merge (GstCaps * caps1, GstCaps * caps2)
643 GstStructure *structure;
646 g_return_if_fail (GST_IS_CAPS (caps1));
647 g_return_if_fail (GST_IS_CAPS (caps2));
648 g_return_if_fail (IS_WRITABLE (caps1));
649 g_return_if_fail (IS_WRITABLE (caps2));
654 if (G_UNLIKELY (gst_caps_is_any (caps1))) {
655 for (i = caps2->structs->len - 1; i >= 0; i--) {
656 structure = gst_caps_remove_and_get_structure (caps2, i);
657 gst_structure_free (structure);
659 } else if (G_UNLIKELY (gst_caps_is_any (caps2))) {
660 caps1->flags |= GST_CAPS_FLAGS_ANY;
661 for (i = caps1->structs->len - 1; i >= 0; i--) {
662 structure = gst_caps_remove_and_get_structure (caps1, i);
663 gst_structure_free (structure);
666 for (i = caps2->structs->len; i; i--) {
667 structure = gst_caps_remove_and_get_structure (caps2, 0);
668 gst_caps_merge_structure (caps1, structure);
671 GstCaps *com = gst_caps_intersect (caps1, caps2);
672 GstCaps *add = gst_caps_subtract (caps2, com);
674 GST_DEBUG ("common : %d", gst_caps_get_size (com));
675 GST_DEBUG ("adding : %d", gst_caps_get_size (add));
676 gst_caps_append (caps1, add);
677 gst_caps_unref (com);
680 gst_caps_unref (caps2); /* guaranteed to free it */
684 * gst_caps_append_structure:
685 * @caps: the #GstCaps that will be appended to
686 * @structure: the #GstStructure to append
688 * Appends @structure to @caps. The structure is not copied; @caps
689 * becomes the owner of @structure.
692 gst_caps_append_structure (GstCaps * caps, GstStructure * structure)
694 g_return_if_fail (GST_IS_CAPS (caps));
695 g_return_if_fail (IS_WRITABLE (caps));
697 if (G_LIKELY (structure)) {
698 g_return_if_fail (structure->parent_refcount == NULL);
701 STRUCTURE_POISON (structure);
704 gst_structure_set_parent_refcount (structure, &caps->refcount);
705 g_ptr_array_add (caps->structs, structure);
710 * gst_caps_remove_structure:
711 * @caps: the #GstCaps to remove from
712 * @idx: Index of the structure to remove
714 * removes the stucture with the given index from the list of structures
715 * contained in @caps.
718 gst_caps_remove_structure (GstCaps * caps, guint idx)
720 GstStructure *structure;
722 g_return_if_fail (caps != NULL);
723 g_return_if_fail (idx <= gst_caps_get_size (caps));
724 g_return_if_fail (IS_WRITABLE (caps));
726 structure = gst_caps_remove_and_get_structure (caps, idx);
727 gst_structure_free (structure);
731 * gst_caps_merge_structure:
732 * @caps: the #GstCaps that will the the new structure
733 * @structure: the #GstStructure to merge
735 * Appends @structure to @caps if its not already expressed by @caps. The
736 * structure is not copied; @caps becomes the owner of @structure.
739 gst_caps_merge_structure (GstCaps * caps, GstStructure * structure)
741 g_return_if_fail (GST_IS_CAPS (caps));
742 g_return_if_fail (IS_WRITABLE (caps));
744 if (G_LIKELY (structure)) {
745 GstStructure *structure1;
747 gboolean unique = TRUE;
749 g_return_if_fail (structure->parent_refcount == NULL);
752 STRUCTURE_POISON (structure);
755 /* check each structure */
756 for (i = caps->structs->len - 1; i >= 0; i--) {
757 structure1 = gst_caps_get_structure_unchecked (caps, i);
758 /* if structure is a subset of structure1, then skip it */
759 if (gst_caps_structure_is_subset (structure1, structure)) {
765 gst_structure_set_parent_refcount (structure, &caps->refcount);
766 g_ptr_array_add (caps->structs, structure);
768 gst_structure_free (structure);
778 * Gets the number of structures contained in @caps.
780 * Returns: the number of structures that @caps contains
783 gst_caps_get_size (const GstCaps * caps)
785 g_return_val_if_fail (GST_IS_CAPS (caps), 0);
787 return caps->structs->len;
791 * gst_caps_get_structure:
793 * @index: the index of the structure
795 * Finds the structure in @caps that has the index @index, and
798 * WARNING: This function takes a const GstCaps *, but returns a
799 * non-const GstStructure *. This is for programming convenience --
800 * the caller should be aware that structures inside a constant
801 * #GstCaps should not be modified. However, if you know the caps
802 * are writable, either because you have just copied them or made
803 * them writable with gst_caps_make_writable(), you may modify the
804 * structure returned in the usual way, e.g. with functions like
805 * gst_structure_set_simple().
807 * You do not need to free or unref the structure returned, it
808 * belongs to the #GstCaps.
810 * Returns: a pointer to the #GstStructure corresponding to @index
813 gst_caps_get_structure (const GstCaps * caps, guint index)
815 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
816 g_return_val_if_fail (index < caps->structs->len, NULL);
818 return gst_caps_get_structure_unchecked (caps, index);
823 * @caps: the #GstCaps to copy
824 * @nth: the nth structure to copy
826 * Creates a new #GstCaps and appends a copy of the nth structure
827 * contained in @caps.
829 * Returns: the new #GstCaps
832 gst_caps_copy_nth (const GstCaps * caps, guint nth)
835 GstStructure *structure;
837 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
839 newcaps = gst_caps_new_empty ();
840 newcaps->flags = caps->flags;
842 if (G_LIKELY (caps->structs->len > nth)) {
843 structure = gst_caps_get_structure_unchecked (caps, nth);
844 gst_caps_append_structure (newcaps, gst_structure_copy (structure));
852 * @caps: the #GstCaps to truncate
854 * Destructively discard all but the first structure from @caps. Useful when
855 * fixating. @caps must be writable.
858 gst_caps_truncate (GstCaps * caps)
862 g_return_if_fail (GST_IS_CAPS (caps));
863 g_return_if_fail (IS_WRITABLE (caps));
865 i = caps->structs->len - 1;
868 gst_caps_remove_structure (caps, i--);
872 * gst_caps_set_simple:
873 * @caps: the #GstCaps to set
874 * @field: first field to set
875 * @...: additional parameters
877 * Sets fields in a simple #GstCaps. A simple #GstCaps is one that
878 * only has one structure. The arguments must be passed in the same
879 * manner as gst_structure_set(), and be NULL-terminated.
882 gst_caps_set_simple (GstCaps * caps, const char *field, ...)
884 GstStructure *structure;
887 g_return_if_fail (GST_IS_CAPS (caps));
888 g_return_if_fail (caps->structs->len == 1);
889 g_return_if_fail (IS_WRITABLE (caps));
891 structure = gst_caps_get_structure_unchecked (caps, 0);
893 va_start (var_args, field);
894 gst_structure_set_valist (structure, field, var_args);
899 * gst_caps_set_simple_valist:
900 * @caps: the #GstCaps to copy
901 * @field: first field to set
902 * @varargs: additional parameters
904 * Sets fields in a simple #GstCaps. A simple #GstCaps is one that
905 * only has one structure. The arguments must be passed in the same
906 * manner as gst_structure_set(), and be NULL-terminated.
909 gst_caps_set_simple_valist (GstCaps * caps, const char *field, va_list varargs)
911 GstStructure *structure;
913 g_return_if_fail (GST_IS_CAPS (caps));
914 g_return_if_fail (caps->structs->len == 1);
915 g_return_if_fail (IS_WRITABLE (caps));
917 structure = gst_caps_get_structure_unchecked (caps, 0);
919 gst_structure_set_valist (structure, field, varargs);
926 * @caps: the #GstCaps to test
928 * Determines if @caps represents any media format.
930 * Returns: TRUE if @caps represents any format.
933 gst_caps_is_any (const GstCaps * caps)
935 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
937 return (caps->flags & GST_CAPS_FLAGS_ANY);
942 * @caps: the #GstCaps to test
944 * Determines if @caps represents no media formats.
946 * Returns: TRUE if @caps represents no formats.
949 gst_caps_is_empty (const GstCaps * caps)
951 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
953 if (caps->flags & GST_CAPS_FLAGS_ANY)
956 return (caps->structs == NULL) || (caps->structs->len == 0);
960 gst_caps_is_fixed_foreach (GQuark field_id, const GValue * value,
963 return gst_value_is_fixed (value);
968 * @caps: the #GstCaps to test
970 * Fixed #GstCaps describe exactly one format, that is, they have exactly
971 * one structure, and each field in the structure describes a fixed type.
972 * Examples of non-fixed types are GST_TYPE_INT_RANGE and GST_TYPE_LIST.
974 * Returns: TRUE if @caps is fixed
977 gst_caps_is_fixed (const GstCaps * caps)
979 GstStructure *structure;
981 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
983 if (caps->structs->len != 1)
986 structure = gst_caps_get_structure_unchecked (caps, 0);
988 return gst_structure_foreach (structure, gst_caps_is_fixed_foreach, NULL);
992 * gst_caps_is_equal_fixed:
993 * @caps1: the #GstCaps to test
994 * @caps2: the #GstCaps to test
996 * Tests if two #GstCaps are equal. This function only works on fixed
999 * Returns: TRUE if the arguments represent the same format
1002 gst_caps_is_equal_fixed (const GstCaps * caps1, const GstCaps * caps2)
1004 GstStructure *struct1, *struct2;
1006 g_return_val_if_fail (gst_caps_is_fixed (caps1), FALSE);
1007 g_return_val_if_fail (gst_caps_is_fixed (caps2), FALSE);
1009 struct1 = gst_caps_get_structure_unchecked (caps1, 0);
1010 struct2 = gst_caps_get_structure_unchecked (caps2, 0);
1012 if (struct1->name != struct2->name) {
1015 if (struct1->fields->len != struct2->fields->len) {
1019 return gst_structure_foreach (struct1, gst_structure_is_equal_foreach,
1024 * gst_caps_is_always_compatible:
1025 * @caps1: the #GstCaps to test
1026 * @caps2: the #GstCaps to test
1028 * A given #GstCaps structure is always compatible with another if
1029 * every media format that is in the first is also contained in the
1030 * second. That is, @caps1 is a subset of @caps2.
1032 * Returns: TRUE if @caps1 is a subset of @caps2.
1035 gst_caps_is_always_compatible (const GstCaps * caps1, const GstCaps * caps2)
1037 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1038 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1040 return gst_caps_is_subset (caps1, caps2);
1044 * gst_caps_is_subset:
1045 * @subset: a #GstCaps
1046 * @superset: a potentially greater #GstCaps
1048 * Checks if all caps represented by @subset are also represented by @superset.
1049 * <note>This function does not work reliably if optional properties for caps
1050 * are included on one caps and omitted on the other.</note>
1052 * Returns: %TRUE if @subset is a subset of @superset
1055 gst_caps_is_subset (const GstCaps * subset, const GstCaps * superset)
1060 g_return_val_if_fail (subset != NULL, FALSE);
1061 g_return_val_if_fail (superset != NULL, FALSE);
1063 if (gst_caps_is_empty (subset) || gst_caps_is_any (superset))
1065 if (gst_caps_is_any (subset) || gst_caps_is_empty (superset))
1068 caps = gst_caps_subtract (subset, superset);
1069 ret = gst_caps_is_empty (caps);
1070 gst_caps_unref (caps);
1075 * gst_caps_is_equal:
1076 * @caps1: a #GstCaps
1077 * @caps2: another #GstCaps
1079 * Checks if the given caps represent the same set of caps.
1080 * <note>This function does not work reliably if optional properties for caps
1081 * are included on one caps and omitted on the other.</note>
1083 * This function deals correctly with passing NULL for any of the caps.
1085 * Returns: TRUE if both caps are equal.
1088 gst_caps_is_equal (const GstCaps * caps1, const GstCaps * caps2)
1090 /* FIXME 0.11: NULL pointers are no valid Caps but indicate an error
1091 * So there should be an assertion that caps1 and caps2 != NULL */
1093 /* NULL <-> NULL is allowed here */
1094 if (G_UNLIKELY (caps1 == caps2))
1097 /* one of them NULL => they are different (can't be both NULL because
1098 * we checked that above) */
1099 if (G_UNLIKELY (caps1 == NULL || caps2 == NULL))
1102 if (G_UNLIKELY (gst_caps_is_fixed (caps1) && gst_caps_is_fixed (caps2)))
1103 return gst_caps_is_equal_fixed (caps1, caps2);
1105 return gst_caps_is_subset (caps1, caps2) && gst_caps_is_subset (caps2, caps1);
1111 const GstStructure *intersect;
1116 gst_caps_structure_intersect_field1 (GQuark id, const GValue * val1,
1119 IntersectData *idata = (IntersectData *) data;
1120 const GValue *val2 = gst_structure_id_get_value (idata->intersect, id);
1122 if (G_UNLIKELY (val2 == NULL)) {
1123 gst_structure_id_set_value (idata->dest, id, val1);
1125 GValue dest_value = { 0 };
1126 if (gst_value_intersect (&dest_value, val1, val2)) {
1127 gst_structure_id_set_value (idata->dest, id, &dest_value);
1128 g_value_unset (&dest_value);
1137 gst_caps_structure_intersect_field2 (GQuark id, const GValue * val1,
1140 IntersectData *idata = (IntersectData *) data;
1141 const GValue *val2 = gst_structure_id_get_value (idata->intersect, id);
1143 if (G_UNLIKELY (val2 == NULL)) {
1144 gst_structure_id_set_value (idata->dest, id, val1);
1149 static GstStructure *
1150 gst_caps_structure_intersect (const GstStructure * struct1,
1151 const GstStructure * struct2)
1155 g_return_val_if_fail (struct1 != NULL, NULL);
1156 g_return_val_if_fail (struct2 != NULL, NULL);
1158 if (G_UNLIKELY (struct1->name != struct2->name))
1161 /* copy fields from struct1 which we have not in struct2 to target
1162 * intersect if we have the field in both */
1163 data.dest = gst_structure_id_empty_new (struct1->name);
1164 data.intersect = struct2;
1165 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct1,
1166 gst_caps_structure_intersect_field1, &data)))
1169 /* copy fields from struct2 which we have not in struct1 to target */
1170 data.intersect = struct1;
1171 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct2,
1172 gst_caps_structure_intersect_field2, &data)))
1178 gst_structure_free (data.dest);
1183 gst_caps_structure_can_intersect_field (GQuark id, const GValue * val1,
1186 GstStructure *other = (GstStructure *) data;
1187 const GValue *val2 = gst_structure_id_get_value (other, id);
1189 if (G_LIKELY (val2)) {
1190 if (!gst_value_can_intersect (val1, val2)) {
1193 gint eq = gst_value_compare (val1, val2);
1195 if (eq == GST_VALUE_UNORDERED) {
1196 /* we need to try interseting */
1197 GValue dest_value = { 0 };
1198 if (gst_value_intersect (&dest_value, val1, val2)) {
1199 g_value_unset (&dest_value);
1203 } else if (eq != GST_VALUE_EQUAL) {
1212 gst_caps_structure_can_intersect (const GstStructure * struct1,
1213 const GstStructure * struct2)
1215 g_return_val_if_fail (struct1 != NULL, FALSE);
1216 g_return_val_if_fail (struct2 != NULL, FALSE);
1218 if (G_UNLIKELY (struct1->name != struct2->name))
1221 /* tries to intersect if we have the field in both */
1222 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct1,
1223 gst_caps_structure_can_intersect_field, (gpointer) struct2)))
1230 * gst_caps_can_intersect:
1231 * @caps1: a #GstCaps to intersect
1232 * @caps2: a #GstCaps to intersect
1234 * Tries intersecting @caps1 and @caps2 and reports wheter the result would not
1237 * Returns: %TRUE if intersection would be not empty
1242 gst_caps_can_intersect (const GstCaps * caps1, const GstCaps * caps2)
1244 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1245 guint j, k, len1, len2;
1246 GstStructure *struct1;
1247 GstStructure *struct2;
1249 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1250 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1252 /* caps are exactly the same pointers */
1253 if (G_UNLIKELY (caps1 == caps2))
1256 /* empty caps on either side, return empty */
1257 if (G_UNLIKELY (gst_caps_is_empty (caps1) || gst_caps_is_empty (caps2)))
1260 /* one of the caps is any */
1261 if (G_UNLIKELY (gst_caps_is_any (caps1) || gst_caps_is_any (caps2)))
1264 /* run zigzag on top line then right line, this preserves the caps order
1265 * much better than a simple loop.
1267 * This algorithm zigzags over the caps structures as demonstrated in
1268 * the folowing matrix:
1276 * First we iterate over the caps1 structures (top line) intersecting
1277 * the structures diagonally down, then we iterate over the caps2
1280 len1 = caps1->structs->len;
1281 len2 = caps2->structs->len;
1282 for (i = 0; i < len1 + len2 - 1; i++) {
1283 /* superset index goes from 0 to sgst_caps_structure_intersectuperset->structs->len-1 */
1284 j = MIN (i, len1 - 1);
1285 /* subset index stays 0 until i reaches superset->structs->len, then it
1286 * counts up from 1 to subset->structs->len - 1 */
1289 /* now run the diagonal line, end condition is the left or bottom
1292 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1293 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1295 if (gst_caps_structure_can_intersect (struct1, struct2)) {
1298 /* move down left */
1300 if (G_UNLIKELY (j == 0))
1301 break; /* so we don't roll back to G_MAXUINT */
1309 static GstStructure *
1310 gst_caps_structure_union (const GstStructure * struct1,
1311 const GstStructure * struct2)
1315 const GstStructureField *field1;
1316 const GstStructureField *field2;
1319 /* FIXME this doesn't actually work */
1321 if (struct1->name != struct2->name)
1324 dest = gst_structure_id_empty_new (struct1->name);
1326 for (i = 0; i < struct1->fields->len; i++) {
1327 GValue dest_value = { 0 };
1329 field1 = GST_STRUCTURE_FIELD (struct1, i);
1330 field2 = gst_structure_id_get_field (struct2, field1->name);
1332 if (field2 == NULL) {
1335 if (gst_value_union (&dest_value, &field1->value, &field2->value)) {
1336 gst_structure_set_value (dest, g_quark_to_string (field1->name),
1339 ret = gst_value_compare (&field1->value, &field2->value);
1351 * gst_caps_intersect:
1352 * @caps1: a #GstCaps to intersect
1353 * @caps2: a #GstCaps to intersect
1355 * Creates a new #GstCaps that contains all the formats that are common
1356 * to both @caps1 and @caps2.
1358 * Returns: the new #GstCaps
1361 gst_caps_intersect (const GstCaps * caps1, const GstCaps * caps2)
1363 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1364 guint j, k, len1, len2;
1366 GstStructure *struct1;
1367 GstStructure *struct2;
1369 GstStructure *istruct;
1371 g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
1372 g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
1374 /* caps are exactly the same pointers, just copy one caps */
1375 if (G_UNLIKELY (caps1 == caps2))
1376 return gst_caps_copy (caps1);
1378 /* empty caps on either side, return empty */
1379 if (G_UNLIKELY (gst_caps_is_empty (caps1) || gst_caps_is_empty (caps2)))
1380 return gst_caps_new_empty ();
1382 /* one of the caps is any, just copy the other caps */
1383 if (G_UNLIKELY (gst_caps_is_any (caps1)))
1384 return gst_caps_copy (caps2);
1385 if (G_UNLIKELY (gst_caps_is_any (caps2)))
1386 return gst_caps_copy (caps1);
1388 dest = gst_caps_new_empty ();
1390 /* run zigzag on top line then right line, this preserves the caps order
1391 * much better than a simple loop.
1393 * This algorithm zigzags over the caps structures as demonstrated in
1394 * the folowing matrix:
1402 * First we iterate over the caps1 structures (top line) intersecting
1403 * the structures diagonally down, then we iterate over the caps2
1406 len1 = caps1->structs->len;
1407 len2 = caps2->structs->len;
1408 for (i = 0; i < len1 + len2 - 1; i++) {
1409 /* caps1 index goes from 0 to caps1->structs->len-1 */
1410 j = MIN (i, len1 - 1);
1411 /* caps2 index stays 0 until i reaches caps1->structs->len, then it counts
1412 * up from 1 to caps2->structs->len - 1 */
1415 /* now run the diagonal line, end condition is the left or bottom
1418 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1419 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1421 istruct = gst_caps_structure_intersect (struct1, struct2);
1423 gst_caps_append_structure (dest, istruct);
1424 /* move down left */
1426 if (G_UNLIKELY (j == 0))
1427 break; /* so we don't roll back to G_MAXUINT */
1436 const GstStructure *subtract_from;
1443 gst_caps_structure_subtract_field (GQuark field_id, const GValue * value,
1446 SubtractionEntry *e = user_data;
1447 GValue subtraction = { 0, };
1448 const GValue *other;
1449 GstStructure *structure;
1451 other = gst_structure_id_get_value (e->subtract_from, field_id);
1455 if (!gst_value_subtract (&subtraction, other, value))
1457 if (gst_value_compare (&subtraction, other) == GST_VALUE_EQUAL) {
1458 g_value_unset (&subtraction);
1461 structure = gst_structure_copy (e->subtract_from);
1462 gst_structure_id_set_value (structure, field_id, &subtraction);
1463 g_value_unset (&subtraction);
1464 e->put_into = g_slist_prepend (e->put_into, structure);
1470 gst_caps_structure_subtract (GSList ** into, const GstStructure * minuend,
1471 const GstStructure * subtrahend)
1476 e.subtract_from = minuend;
1479 ret = gst_structure_foreach ((GstStructure *) subtrahend,
1480 gst_caps_structure_subtract_field, &e);
1486 for (walk = e.put_into; walk; walk = g_slist_next (walk)) {
1487 gst_structure_free (walk->data);
1489 g_slist_free (e.put_into);
1495 * gst_caps_subtract:
1496 * @minuend: #GstCaps to substract from
1497 * @subtrahend: #GstCaps to substract
1499 * Subtracts the @subtrahend from the @minuend.
1500 * <note>This function does not work reliably if optional properties for caps
1501 * are included on one caps and omitted on the other.</note>
1503 * Returns: the resulting caps
1506 gst_caps_subtract (const GstCaps * minuend, const GstCaps * subtrahend)
1511 GstCaps *dest = NULL, *src;
1513 g_return_val_if_fail (minuend != NULL, NULL);
1514 g_return_val_if_fail (subtrahend != NULL, NULL);
1516 if (gst_caps_is_empty (minuend) || gst_caps_is_any (subtrahend)) {
1517 return gst_caps_new_empty ();
1519 if (gst_caps_is_empty (subtrahend))
1520 return gst_caps_copy (minuend);
1522 /* FIXME: Do we want this here or above?
1523 The reason we need this is that there is no definition about what
1524 ANY means for specific types, so it's not possible to reduce ANY partially
1525 You can only remove everything or nothing and that is done above.
1526 Note: there's a test that checks this behaviour. */
1527 g_return_val_if_fail (!gst_caps_is_any (minuend), NULL);
1528 sublen = subtrahend->structs->len;
1529 g_assert (sublen > 0);
1531 src = gst_caps_copy (minuend);
1532 for (i = 0; i < sublen; i++) {
1535 sub = gst_caps_get_structure_unchecked (subtrahend, i);
1537 gst_caps_unref (src);
1540 dest = gst_caps_new_empty ();
1541 srclen = src->structs->len;
1542 for (j = 0; j < srclen; j++) {
1543 min = gst_caps_get_structure_unchecked (src, j);
1544 if (gst_structure_get_name_id (min) == gst_structure_get_name_id (sub)) {
1547 if (gst_caps_structure_subtract (&list, min, sub)) {
1550 for (walk = list; walk; walk = g_slist_next (walk)) {
1551 gst_caps_append_structure (dest, (GstStructure *) walk->data);
1553 g_slist_free (list);
1555 gst_caps_append_structure (dest, gst_structure_copy (min));
1558 gst_caps_append_structure (dest, gst_structure_copy (min));
1561 if (gst_caps_is_empty (dest)) {
1562 gst_caps_unref (src);
1567 gst_caps_unref (src);
1568 gst_caps_do_simplify (dest);
1574 * @caps1: a #GstCaps to union
1575 * @caps2: a #GstCaps to union
1577 * Creates a new #GstCaps that contains all the formats that are in
1578 * either @caps1 and @caps2.
1580 * Returns: the new #GstCaps
1583 gst_caps_union (const GstCaps * caps1, const GstCaps * caps2)
1588 /* NULL pointers are no correct GstCaps */
1589 g_return_val_if_fail (caps1 != NULL, NULL);
1590 g_return_val_if_fail (caps2 != NULL, NULL);
1592 if (gst_caps_is_empty (caps1))
1593 return gst_caps_copy (caps2);
1595 if (gst_caps_is_empty (caps2))
1596 return gst_caps_copy (caps1);
1598 if (gst_caps_is_any (caps1) || gst_caps_is_any (caps2))
1599 return gst_caps_new_any ();
1601 dest1 = gst_caps_copy (caps1);
1602 dest2 = gst_caps_copy (caps2);
1603 gst_caps_append (dest1, dest2);
1605 gst_caps_do_simplify (dest1);
1609 typedef struct _NormalizeForeach
1612 GstStructure *structure;
1617 gst_caps_normalize_foreach (GQuark field_id, const GValue * value, gpointer ptr)
1619 NormalizeForeach *nf = (NormalizeForeach *) ptr;
1623 if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
1624 guint len = gst_value_list_get_size (value);
1625 for (i = 1; i < len; i++) {
1626 const GValue *v = gst_value_list_get_value (value, i);
1627 GstStructure *structure = gst_structure_copy (nf->structure);
1629 gst_structure_id_set_value (structure, field_id, v);
1630 gst_caps_append_structure (nf->caps, structure);
1633 gst_value_init_and_copy (&val, gst_value_list_get_value (value, 0));
1634 gst_structure_id_set_value (nf->structure, field_id, &val);
1635 g_value_unset (&val);
1643 * gst_caps_normalize:
1644 * @caps: a #GstCaps to normalize
1646 * Creates a new #GstCaps that represents the same set of formats as
1647 * @caps, but contains no lists. Each list is expanded into separate
1650 * Returns: the new #GstCaps
1653 gst_caps_normalize (const GstCaps * caps)
1655 NormalizeForeach nf;
1659 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
1661 newcaps = gst_caps_copy (caps);
1663 nlen = newcaps->structs->len;
1665 for (i = 0; i < nlen; i++) {
1666 nf.structure = gst_caps_get_structure_unchecked (newcaps, i);
1668 while (!gst_structure_foreach (nf.structure,
1669 gst_caps_normalize_foreach, &nf));
1676 gst_caps_compare_structures (gconstpointer one, gconstpointer two)
1679 const GstStructure *struct1 = *((const GstStructure **) one);
1680 const GstStructure *struct2 = *((const GstStructure **) two);
1682 /* FIXME: this orders alphabetically, but ordering the quarks might be faster
1683 So what's the best way? */
1684 ret = strcmp (gst_structure_get_name (struct1),
1685 gst_structure_get_name (struct2));
1689 return gst_structure_n_fields (struct2) - gst_structure_n_fields (struct1);
1696 GstStructure *compare;
1701 gst_caps_structure_figure_out_union (GQuark field_id, const GValue * value,
1704 UnionField *u = user_data;
1705 const GValue *val = gst_structure_id_get_value (u->compare, field_id);
1709 g_value_unset (&u->value);
1712 if (gst_value_compare (val, value) == GST_VALUE_EQUAL)
1715 g_value_unset (&u->value);
1719 gst_value_union (&u->value, val, value);
1724 gst_caps_structure_simplify (GstStructure ** result,
1725 const GstStructure * simplify, GstStructure * compare)
1728 UnionField field = { 0, {0,}, NULL };
1730 /* try to subtract to get a real subset */
1731 if (gst_caps_structure_subtract (&list, simplify, compare)) {
1732 switch (g_slist_length (list)) {
1737 *result = list->data;
1738 g_slist_free (list);
1744 for (walk = list; walk; walk = g_slist_next (walk)) {
1745 gst_structure_free (walk->data);
1747 g_slist_free (list);
1753 /* try to union both structs */
1754 field.compare = compare;
1755 if (gst_structure_foreach ((GstStructure *) simplify,
1756 gst_caps_structure_figure_out_union, &field)) {
1757 gboolean ret = FALSE;
1759 /* now we know all of simplify's fields are the same in compare
1760 * but at most one field: field.name */
1761 if (G_IS_VALUE (&field.value)) {
1762 if (gst_structure_n_fields (simplify) == gst_structure_n_fields (compare)) {
1763 gst_structure_id_set_value (compare, field.name, &field.value);
1767 g_value_unset (&field.value);
1768 } else if (gst_structure_n_fields (simplify) <=
1769 gst_structure_n_fields (compare)) {
1770 /* compare is just more specific, will be optimized away later */
1771 /* FIXME: do this here? */
1772 GST_LOG ("found a case that will be optimized later.");
1774 gchar *one = gst_structure_to_string (simplify);
1775 gchar *two = gst_structure_to_string (compare);
1778 ("caps mismatch: structures %s and %s claim to be possible to unify, but aren't",
1790 gst_caps_switch_structures (GstCaps * caps, GstStructure * old,
1791 GstStructure * new, gint i)
1793 gst_structure_set_parent_refcount (old, NULL);
1794 gst_structure_free (old);
1795 gst_structure_set_parent_refcount (new, &caps->refcount);
1796 g_ptr_array_index (caps->structs, i) = new;
1800 * gst_caps_do_simplify:
1801 * @caps: a #GstCaps to simplify
1803 * Modifies the given @caps inplace into a representation that represents the
1804 * same set of formats, but in a simpler form. Component structures that are
1805 * identical are merged. Component structures that have values that can be
1806 * merged are also merged.
1808 * Returns: TRUE, if the caps could be simplified
1811 gst_caps_do_simplify (GstCaps * caps)
1813 GstStructure *simplify, *compare, *result = NULL;
1815 gboolean changed = FALSE;
1817 g_return_val_if_fail (caps != NULL, FALSE);
1818 g_return_val_if_fail (IS_WRITABLE (caps), FALSE);
1820 if (gst_caps_get_size (caps) < 2)
1823 g_ptr_array_sort (caps->structs, gst_caps_compare_structures);
1825 start = caps->structs->len - 1;
1826 for (i = caps->structs->len - 1; i >= 0; i--) {
1827 simplify = gst_caps_get_structure_unchecked (caps, i);
1828 if (gst_structure_get_name_id (simplify) !=
1829 gst_structure_get_name_id (gst_caps_get_structure_unchecked (caps,
1832 for (j = start; j >= 0; j--) {
1835 compare = gst_caps_get_structure_unchecked (caps, j);
1836 if (gst_structure_get_name_id (simplify) !=
1837 gst_structure_get_name_id (compare)) {
1840 if (gst_caps_structure_simplify (&result, simplify, compare)) {
1842 gst_caps_switch_structures (caps, simplify, result, i);
1845 gst_caps_remove_structure (caps, i);
1857 /* gst_caps_do_simplify (caps); */
1861 #ifndef GST_DISABLE_LOADSAVE
1863 * gst_caps_save_thyself:
1864 * @caps: a #GstCaps structure
1865 * @parent: a XML parent node
1867 * Serializes a #GstCaps to XML and adds it as a child node of @parent.
1869 * Returns: a XML node pointer
1872 gst_caps_save_thyself (const GstCaps * caps, xmlNodePtr parent)
1874 char *s = gst_caps_to_string (caps);
1876 xmlNewChild (parent, NULL, (xmlChar *) "caps", (xmlChar *) s);
1882 * gst_caps_load_thyself:
1883 * @parent: a XML node
1885 * Creates a #GstCaps from its XML serialization.
1887 * Returns: a new #GstCaps structure
1890 gst_caps_load_thyself (xmlNodePtr parent)
1892 if (strcmp ("caps", (char *) parent->name) == 0) {
1893 return gst_caps_from_string ((gchar *) xmlNodeGetContent (parent));
1904 * @caps: a pointer to #GstCaps
1905 * @newcaps: a #GstCaps to replace *caps
1907 * Replaces *caps with @newcaps. Unrefs the #GstCaps in the location
1908 * pointed to by @caps, if applicable, then modifies @caps to point to
1909 * @newcaps. An additional ref on @newcaps is taken.
1911 * This function does not take any locks so you might want to lock
1912 * the object owning @caps pointer.
1915 gst_caps_replace (GstCaps ** caps, GstCaps * newcaps)
1919 g_return_if_fail (caps != NULL);
1923 GST_CAT_LOG (GST_CAT_REFCOUNTING, "%p, %p -> %p", caps, oldcaps, newcaps);
1925 if (newcaps != oldcaps) {
1927 gst_caps_ref (newcaps);
1932 gst_caps_unref (oldcaps);
1937 * gst_caps_to_string:
1940 * Converts @caps to a string representation. This string representation
1941 * can be converted back to a #GstCaps by gst_caps_from_string().
1943 * For debugging purposes its easier to do something like this:
1945 * GST_LOG ("caps are %" GST_PTR_FORMAT, caps);
1947 * This prints the caps in human readble form.
1949 * Returns: a newly allocated string representing @caps.
1952 gst_caps_to_string (const GstCaps * caps)
1954 guint i, slen, clen;
1957 /* NOTE: This function is potentially called by the debug system,
1958 * so any calls to gst_log() (and GST_DEBUG(), GST_LOG(), etc.)
1959 * should be careful to avoid recursion. This includes any functions
1960 * called by gst_caps_to_string. In particular, calls should
1961 * not use the GST_PTR_FORMAT extension. */
1964 return g_strdup ("NULL");
1966 if (gst_caps_is_any (caps)) {
1967 return g_strdup ("ANY");
1969 if (gst_caps_is_empty (caps)) {
1970 return g_strdup ("EMPTY");
1973 /* estimate a rough string length to avoid unnecessary reallocs in GString */
1975 clen = caps->structs->len;
1976 for (i = 0; i < clen; i++) {
1978 STRUCTURE_ESTIMATED_STRING_LEN (gst_caps_get_structure_unchecked (caps,
1982 s = g_string_sized_new (slen);
1983 for (i = 0; i < clen; i++) {
1984 GstStructure *structure;
1987 /* ';' is now added by gst_structure_to_string */
1988 g_string_append_c (s, ' ');
1991 structure = gst_caps_get_structure_unchecked (caps, i);
1992 priv_gst_structure_append_to_gstring (structure, s);
1994 if (s->len && s->str[s->len - 1] == ';') {
1995 /* remove latest ';' */
1996 s->str[--s->len] = '\0';
1998 return g_string_free (s, FALSE);
2002 gst_caps_from_string_inplace (GstCaps * caps, const gchar * string)
2004 GstStructure *structure;
2007 g_return_val_if_fail (string, FALSE);
2008 if (strcmp ("ANY", string) == 0) {
2009 caps->flags = GST_CAPS_FLAGS_ANY;
2012 if (strcmp ("EMPTY", string) == 0) {
2016 structure = gst_structure_from_string (string, &s);
2017 if (structure == NULL) {
2020 gst_caps_append_structure (caps, structure);
2024 while (g_ascii_isspace (*s))
2029 structure = gst_structure_from_string (s, &s);
2030 if (structure == NULL) {
2033 gst_caps_append_structure (caps, structure);
2041 * gst_caps_from_string:
2042 * @string: a string to convert to #GstCaps
2044 * Converts @caps from a string representation.
2046 * Returns: a newly allocated #GstCaps
2049 gst_caps_from_string (const gchar * string)
2053 caps = gst_caps_new_empty ();
2054 if (gst_caps_from_string_inplace (caps, string)) {
2057 gst_caps_unref (caps);
2063 gst_caps_transform_to_string (const GValue * src_value, GValue * dest_value)
2065 g_return_if_fail (G_IS_VALUE (src_value));
2066 g_return_if_fail (G_IS_VALUE (dest_value));
2067 g_return_if_fail (G_VALUE_HOLDS (src_value, GST_TYPE_CAPS));
2068 g_return_if_fail (G_VALUE_HOLDS (dest_value, G_TYPE_STRING)
2069 || G_VALUE_HOLDS (dest_value, G_TYPE_POINTER));
2071 dest_value->data[0].v_pointer =
2072 gst_caps_to_string (src_value->data[0].v_pointer);
2076 gst_caps_copy_conditional (GstCaps * src)
2079 return gst_caps_ref (src);