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., 51 Franklin St, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
22 * @short_description: Structure describing sets of media formats
23 * @see_also: #GstStructure, #GstMiniObject
25 * Caps (capabilities) are lightweight 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_query_caps() pad
33 * function. This function describes the possible types that the pad can
34 * handle or produce at runtime.
36 * A #GstCaps can be constructed with the following code fragment:
38 * GstCaps *caps = gst_caps_new_simple ("video/x-raw",
39 * "format", G_TYPE_STRING, "I420",
40 * "framerate", GST_TYPE_FRACTION, 25, 1,
41 * "pixel-aspect-ratio", GST_TYPE_FRACTION, 1, 1,
42 * "width", G_TYPE_INT, 320,
43 * "height", G_TYPE_INT, 240,
47 * A #GstCaps is fixed when it has no properties with ranges or lists. Use
48 * gst_caps_is_fixed() to test for fixed caps. Fixed caps can be used in a
49 * caps event to notify downstream elements of the current media type.
51 * Various methods exist to work with the media types such as subtracting
54 * Be aware that the current #GstCaps / #GstStructure serialization into string
55 * has limited support for nested #GstCaps / #GstStructure fields. It can only
56 * support one level of nesting. Using more levels will lead to unexpected
57 * behavior when using serialization features, such as gst_caps_to_string() or
58 * gst_value_serialize() and their counterparts.
60 * Last reviewed on 2011-03-28 (0.11.3)
69 #include "gst_private.h"
71 #include <gobject/gvaluecollector.h>
73 #define DEBUG_REFCOUNT
75 typedef struct _GstCapsArrayElement
77 GstStructure *structure;
78 GstCapsFeatures *features;
79 } GstCapsArrayElement;
81 typedef struct _GstCapsImpl
88 #define GST_CAPS_ARRAY(c) (((GstCapsImpl *)(c))->array)
90 #define GST_CAPS_LEN(c) (GST_CAPS_ARRAY(c)->len)
92 #define IS_WRITABLE(caps) \
93 (GST_CAPS_REFCOUNT_VALUE (caps) == 1)
95 /* same as gst_caps_is_any () */
96 #define CAPS_IS_ANY(caps) \
97 (GST_CAPS_FLAGS(caps) & GST_CAPS_FLAG_ANY)
99 /* same as gst_caps_is_empty () */
100 #define CAPS_IS_EMPTY(caps) \
101 (!CAPS_IS_ANY(caps) && CAPS_IS_EMPTY_SIMPLE(caps))
103 #define CAPS_IS_EMPTY_SIMPLE(caps) \
104 ((GST_CAPS_ARRAY (caps) == NULL) || (GST_CAPS_LEN (caps) == 0))
106 #define gst_caps_features_copy_conditional(f) ((f && (gst_caps_features_is_any (f) || !gst_caps_features_is_equal (f, GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY))) ? gst_caps_features_copy (f) : NULL)
108 /* quick way to get a caps structure at an index without doing a type or array
110 #define gst_caps_get_structure_unchecked(caps, index) \
111 (g_array_index (GST_CAPS_ARRAY (caps), GstCapsArrayElement, (index)).structure)
112 #define gst_caps_get_features_storage_unchecked(caps, index) \
113 (&g_array_index (GST_CAPS_ARRAY (caps), GstCapsArrayElement, (index)).features)
114 #define gst_caps_get_features_unchecked(caps, index) \
115 (g_atomic_pointer_get (gst_caps_get_features_storage_unchecked (caps, index)))
116 /* quick way to append a structure without checking the args */
117 #define gst_caps_append_structure_unchecked(caps, s, f) G_STMT_START{\
118 GstCapsArrayElement __e={s, f}; \
119 if (gst_structure_set_parent_refcount (__e.structure, &GST_MINI_OBJECT_REFCOUNT(caps)) && \
120 (!__e.features || gst_caps_features_set_parent_refcount (__e.features, &GST_MINI_OBJECT_REFCOUNT(caps)))) \
121 g_array_append_val (GST_CAPS_ARRAY (caps), __e); \
124 /* lock to protect multiple invocations of static caps to caps conversion */
125 G_LOCK_DEFINE_STATIC (static_caps_lock);
127 static void gst_caps_transform_to_string (const GValue * src_value,
128 GValue * dest_value);
129 static gboolean gst_caps_from_string_inplace (GstCaps * caps,
130 const gchar * string);
132 GType _gst_caps_type = 0;
133 GstCaps *_gst_caps_any;
134 GstCaps *_gst_caps_none;
136 GST_DEFINE_MINI_OBJECT_TYPE (GstCaps, gst_caps);
139 _priv_gst_caps_initialize (void)
141 _gst_caps_type = gst_caps_get_type ();
143 _gst_caps_any = gst_caps_new_any ();
144 _gst_caps_none = gst_caps_new_empty ();
146 g_value_register_transform_func (_gst_caps_type,
147 G_TYPE_STRING, gst_caps_transform_to_string);
151 _gst_caps_copy (const GstCaps * caps)
154 GstStructure *structure;
155 GstCapsFeatures *features;
158 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
160 newcaps = gst_caps_new_empty ();
161 GST_CAPS_FLAGS (newcaps) = GST_CAPS_FLAGS (caps);
162 n = GST_CAPS_LEN (caps);
164 GST_CAT_DEBUG_OBJECT (GST_CAT_PERFORMANCE, caps, "doing copy %p -> %p",
167 for (i = 0; i < n; i++) {
168 structure = gst_caps_get_structure_unchecked (caps, i);
169 features = gst_caps_get_features_unchecked (caps, i);
170 gst_caps_append_structure_full (newcaps, gst_structure_copy (structure),
171 gst_caps_features_copy_conditional (features));
177 /* creation/deletion */
179 _gst_caps_free (GstCaps * caps)
181 GstStructure *structure;
182 GstCapsFeatures *features;
185 /* The refcount must be 0, but since we're only called by gst_caps_unref,
186 * don't bother testing. */
187 len = GST_CAPS_LEN (caps);
188 /* This can be used to get statistics about caps sizes */
189 /*GST_CAT_INFO (GST_CAT_CAPS, "caps size: %d", len); */
190 for (i = 0; i < len; i++) {
191 structure = gst_caps_get_structure_unchecked (caps, i);
192 gst_structure_set_parent_refcount (structure, NULL);
193 gst_structure_free (structure);
194 features = gst_caps_get_features_unchecked (caps, i);
196 gst_caps_features_set_parent_refcount (features, NULL);
197 gst_caps_features_free (features);
200 g_array_free (GST_CAPS_ARRAY (caps), TRUE);
202 #ifdef DEBUG_REFCOUNT
203 GST_CAT_TRACE (GST_CAT_CAPS, "freeing caps %p", caps);
205 g_slice_free1 (sizeof (GstCapsImpl), caps);
209 gst_caps_init (GstCaps * caps)
211 gst_mini_object_init (GST_MINI_OBJECT_CAST (caps), 0, _gst_caps_type,
212 (GstMiniObjectCopyFunction) _gst_caps_copy, NULL,
213 (GstMiniObjectFreeFunction) _gst_caps_free);
215 /* the 32 has been determined by logging caps sizes in _gst_caps_free
216 * but g_ptr_array uses 16 anyway if it expands once, so this does not help
218 * GST_CAPS_ARRAY (caps) = g_ptr_array_sized_new (32);
220 GST_CAPS_ARRAY (caps) =
221 g_array_new (FALSE, TRUE, sizeof (GstCapsArrayElement));
225 * gst_caps_new_empty:
227 * Creates a new #GstCaps that is empty. That is, the returned
228 * #GstCaps contains no media formats.
229 * The #GstCaps is guaranteed to be writable.
230 * Caller is responsible for unreffing the returned caps.
232 * Returns: (transfer full): the new #GstCaps
235 gst_caps_new_empty (void)
239 caps = (GstCaps *) g_slice_new (GstCapsImpl);
241 gst_caps_init (caps);
243 #ifdef DEBUG_REFCOUNT
244 GST_CAT_TRACE (GST_CAT_CAPS, "created caps %p", caps);
253 * Creates a new #GstCaps that indicates that it is compatible with
256 * Returns: (transfer full): the new #GstCaps
259 gst_caps_new_any (void)
261 GstCaps *caps = gst_caps_new_empty ();
263 GST_CAPS_FLAG_SET (caps, GST_CAPS_FLAG_ANY);
269 * gst_caps_new_empty_simple:
270 * @media_type: the media type of the structure
272 * Creates a new #GstCaps that contains one #GstStructure with name
274 * Caller is responsible for unreffing the returned caps.
276 * Returns: (transfer full): the new #GstCaps
279 gst_caps_new_empty_simple (const char *media_type)
282 GstStructure *structure;
284 caps = gst_caps_new_empty ();
285 structure = gst_structure_new_empty (media_type);
287 gst_caps_append_structure_unchecked (caps, structure, NULL);
293 * gst_caps_new_simple:
294 * @media_type: the media type of the structure
295 * @fieldname: first field to set
296 * @...: additional arguments
298 * Creates a new #GstCaps that contains one #GstStructure. The
299 * structure is defined by the arguments, which have the same format
300 * as gst_structure_new().
301 * Caller is responsible for unreffing the returned caps.
303 * Returns: (transfer full): the new #GstCaps
306 gst_caps_new_simple (const char *media_type, const char *fieldname, ...)
309 GstStructure *structure;
312 caps = gst_caps_new_empty ();
314 va_start (var_args, fieldname);
315 structure = gst_structure_new_valist (media_type, fieldname, var_args);
319 gst_caps_append_structure_unchecked (caps, structure, NULL);
321 gst_caps_replace (&caps, NULL);
328 * @struct1: the first structure to add
329 * @...: additional structures to add
331 * Creates a new #GstCaps and adds all the structures listed as
332 * arguments. The list must be NULL-terminated. The structures
333 * are not copied; the returned #GstCaps owns the structures.
335 * Returns: (transfer full): the new #GstCaps
338 gst_caps_new_full (GstStructure * struct1, ...)
343 va_start (var_args, struct1);
344 caps = gst_caps_new_full_valist (struct1, var_args);
351 * gst_caps_new_full_valist:
352 * @structure: the first structure to add
353 * @var_args: additional structures to add
355 * Creates a new #GstCaps and adds all the structures listed as
356 * arguments. The list must be NULL-terminated. The structures
357 * are not copied; the returned #GstCaps owns the structures.
359 * Returns: (transfer full): the new #GstCaps
362 gst_caps_new_full_valist (GstStructure * structure, va_list var_args)
366 caps = gst_caps_new_empty ();
369 gst_caps_append_structure_unchecked (caps, structure, NULL);
370 structure = va_arg (var_args, GstStructure *);
376 G_DEFINE_POINTER_TYPE (GstStaticCaps, gst_static_caps);
379 * gst_static_caps_get:
380 * @static_caps: the #GstStaticCaps to convert
382 * Converts a #GstStaticCaps to a #GstCaps.
384 * Returns: (transfer full): a pointer to the #GstCaps. Unref after usage.
385 * Since the core holds an additional ref to the returned caps,
386 * use gst_caps_make_writable() on the returned caps to modify it.
389 gst_static_caps_get (GstStaticCaps * static_caps)
393 g_return_val_if_fail (static_caps != NULL, NULL);
395 caps = &static_caps->caps;
397 /* refcount is 0 when we need to convert */
398 if (G_UNLIKELY (*caps == NULL)) {
401 G_LOCK (static_caps_lock);
402 /* check if other thread already updated */
403 if (G_UNLIKELY (*caps != NULL))
406 string = static_caps->string;
408 if (G_UNLIKELY (string == NULL))
411 *caps = gst_caps_from_string (string);
413 /* convert to string */
414 if (G_UNLIKELY (*caps == NULL))
415 g_critical ("Could not convert static caps \"%s\"", string);
417 GST_CAT_TRACE (GST_CAT_CAPS, "created %p from string %s", static_caps,
420 G_UNLOCK (static_caps_lock);
422 /* ref the caps, makes it not writable */
423 if (G_LIKELY (*caps != NULL))
424 gst_caps_ref (*caps);
431 G_UNLOCK (static_caps_lock);
432 g_warning ("static caps %p string is NULL", static_caps);
438 * gst_static_caps_cleanup:
439 * @static_caps: the #GstStaticCaps to clean
441 * Clean up the cached caps contained in @static_caps.
444 gst_static_caps_cleanup (GstStaticCaps * static_caps)
446 G_LOCK (static_caps_lock);
447 gst_caps_replace (&static_caps->caps, NULL);
448 G_UNLOCK (static_caps_lock);
454 gst_caps_remove_and_get_structure_and_features (GstCaps * caps, guint idx,
455 GstStructure ** s, GstCapsFeatures ** f)
460 s_ = gst_caps_get_structure_unchecked (caps, idx);
461 f_ = gst_caps_get_features_unchecked (caps, idx);
463 /* don't use index_fast, gst_caps_simplify relies on the order */
464 g_array_remove_index (GST_CAPS_ARRAY (caps), idx);
466 gst_structure_set_parent_refcount (s_, NULL);
468 gst_caps_features_set_parent_refcount (f_, NULL);
475 static GstStructure *
476 gst_caps_remove_and_get_structure (GstCaps * caps, guint idx)
481 gst_caps_remove_and_get_structure_and_features (caps, idx, &s, &f);
484 gst_caps_features_free (f);
492 * gst_caps_steal_structure:
493 * @caps: the #GstCaps to retrieve from
494 * @index: Index of the structure to retrieve
496 * Retrieves the structure with the given index from the list of structures
497 * contained in @caps. The caller becomes the owner of the returned structure.
499 * Returns: (transfer full): a pointer to the #GstStructure corresponding
503 gst_caps_steal_structure (GstCaps * caps, guint index)
505 g_return_val_if_fail (caps != NULL, NULL);
506 g_return_val_if_fail (IS_WRITABLE (caps), NULL);
508 if (G_UNLIKELY (index >= GST_CAPS_LEN (caps)))
511 return gst_caps_remove_and_get_structure (caps, index);
516 * @caps1: the #GstCaps that will be appended to
517 * @caps2: (transfer full): the #GstCaps to append
519 * Appends the structures contained in @caps2 to @caps1. The structures in
520 * @caps2 are not copied -- they are transferred to @caps1, and then @caps2 is
521 * freed. If either caps is ANY, the resulting caps will be ANY.
524 gst_caps_append (GstCaps * caps1, GstCaps * caps2)
526 GstStructure *structure;
527 GstCapsFeatures *features;
530 g_return_if_fail (GST_IS_CAPS (caps1));
531 g_return_if_fail (GST_IS_CAPS (caps2));
532 g_return_if_fail (IS_WRITABLE (caps1));
534 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))) {
535 GST_CAPS_FLAGS (caps1) |= GST_CAPS_FLAG_ANY;
536 gst_caps_unref (caps2);
538 caps2 = gst_caps_make_writable (caps2);
540 for (i = GST_CAPS_LEN (caps2); i; i--) {
541 gst_caps_remove_and_get_structure_and_features (caps2, 0, &structure,
543 gst_caps_append_structure_unchecked (caps1, structure, features);
545 gst_caps_unref (caps2); /* guaranteed to free it */
551 * @caps1: (transfer full): the #GstCaps that will take the new entries
552 * @caps2: (transfer full): the #GstCaps to merge in
554 * Appends the structures contained in @caps2 to @caps1 if they are not yet
555 * expressed by @caps1. The structures in @caps2 are not copied -- they are
556 * transferred to a writable copy of @caps1, and then @caps2 is freed.
557 * If either caps is ANY, the resulting caps will be ANY.
559 * Returns: (transfer full): the merged caps.
562 gst_caps_merge (GstCaps * caps1, GstCaps * caps2)
564 GstStructure *structure;
565 GstCapsFeatures *features;
569 g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
570 g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
572 if (G_UNLIKELY (CAPS_IS_ANY (caps1))) {
573 gst_caps_unref (caps2);
575 } else if (G_UNLIKELY (CAPS_IS_ANY (caps2))) {
576 gst_caps_unref (caps1);
579 caps2 = gst_caps_make_writable (caps2);
581 for (i = GST_CAPS_LEN (caps2); i; i--) {
582 gst_caps_remove_and_get_structure_and_features (caps2, 0, &structure,
584 caps1 = gst_caps_merge_structure_full (caps1, structure, features);
586 gst_caps_unref (caps2);
590 GstCaps *com = gst_caps_intersect (caps1, caps2);
591 GstCaps *add = gst_caps_subtract (caps2, com);
593 GST_DEBUG ("common : %d", gst_caps_get_size (com));
594 GST_DEBUG ("adding : %d", gst_caps_get_size (add));
595 gst_caps_append (caps1, add);
596 gst_caps_unref (com);
604 * gst_caps_append_structure:
605 * @caps: the #GstCaps that will be appended to
606 * @structure: (transfer full): the #GstStructure to append
608 * Appends @structure to @caps. The structure is not copied; @caps
609 * becomes the owner of @structure.
612 gst_caps_append_structure (GstCaps * caps, GstStructure * structure)
614 g_return_if_fail (GST_IS_CAPS (caps));
615 g_return_if_fail (IS_WRITABLE (caps));
617 if (G_LIKELY (structure)) {
618 gst_caps_append_structure_unchecked (caps, structure, NULL);
623 * gst_caps_append_structure_full:
624 * @caps: the #GstCaps that will be appended to
625 * @structure: (transfer full): the #GstStructure to append
626 * @features: (transfer full) (allow-none): the #GstCapsFeatures to append
628 * Appends @structure with @features to @caps. The structure is not copied; @caps
629 * becomes the owner of @structure.
634 gst_caps_append_structure_full (GstCaps * caps, GstStructure * structure,
635 GstCapsFeatures * features)
637 g_return_if_fail (GST_IS_CAPS (caps));
638 g_return_if_fail (IS_WRITABLE (caps));
640 if (G_LIKELY (structure)) {
641 gst_caps_append_structure_unchecked (caps, structure, features);
646 * gst_caps_remove_structure:
647 * @caps: the #GstCaps to remove from
648 * @idx: Index of the structure to remove
650 * removes the structure with the given index from the list of structures
651 * contained in @caps.
654 gst_caps_remove_structure (GstCaps * caps, guint idx)
656 GstStructure *structure;
658 g_return_if_fail (caps != NULL);
659 g_return_if_fail (idx <= gst_caps_get_size (caps));
660 g_return_if_fail (IS_WRITABLE (caps));
662 structure = gst_caps_remove_and_get_structure (caps, idx);
663 gst_structure_free (structure);
667 * gst_caps_merge_structure:
668 * @caps: (transfer full): the #GstCaps to merge into
669 * @structure: (transfer full): the #GstStructure to merge
671 * Appends @structure to @caps if its not already expressed by @caps.
673 * Returns: (transfer full): the merged caps.
676 gst_caps_merge_structure (GstCaps * caps, GstStructure * structure)
678 GstStructure *structure1;
679 GstCapsFeatures *features1;
681 gboolean unique = TRUE;
683 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
685 if (G_UNLIKELY (structure == NULL))
688 /* check each structure */
689 for (i = GST_CAPS_LEN (caps) - 1; i >= 0; i--) {
690 structure1 = gst_caps_get_structure_unchecked (caps, i);
691 features1 = gst_caps_get_features_unchecked (caps, i);
693 features1 = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
695 /* if structure is a subset of structure1 and the
696 * there are no existing features, then skip it */
697 if (gst_caps_features_is_equal (features1,
698 GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY)
699 && gst_structure_is_subset (structure, structure1)) {
705 caps = gst_caps_make_writable (caps);
706 gst_caps_append_structure_unchecked (caps, structure, NULL);
708 gst_structure_free (structure);
714 * gst_caps_merge_structure_full:
715 * @caps: (transfer full): the #GstCaps to merge into
716 * @structure: (transfer full): the #GstStructure to merge
717 * @features: (transfer full) (allow-none): the #GstCapsFeatures to merge
719 * Appends @structure with @features to @caps if its not already expressed by @caps.
721 * Returns: (transfer full): the merged caps.
726 gst_caps_merge_structure_full (GstCaps * caps, GstStructure * structure,
727 GstCapsFeatures * features)
729 GstStructure *structure1;
730 GstCapsFeatures *features1, *features_tmp;
732 gboolean unique = TRUE;
734 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
736 if (G_UNLIKELY (structure == NULL))
739 /* To make comparisons easier below */
740 features_tmp = features ? features : GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
742 /* check each structure */
743 for (i = GST_CAPS_LEN (caps) - 1; i >= 0; i--) {
744 structure1 = gst_caps_get_structure_unchecked (caps, i);
745 features1 = gst_caps_get_features_unchecked (caps, i);
747 features1 = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
748 /* if structure is a subset of structure1 and the
749 * the features are a subset, then skip it */
750 /* FIXME: We only skip if none of the features are
751 * ANY and are still equal. That way all ANY structures
752 * show up in the caps and no non-ANY structures are
753 * swallowed by ANY structures
755 if (((!gst_caps_features_is_any (features_tmp)
756 || gst_caps_features_is_any (features1))
757 && gst_caps_features_is_equal (features_tmp, features1))
758 && gst_structure_is_subset (structure, structure1)) {
764 caps = gst_caps_make_writable (caps);
765 gst_caps_append_structure_unchecked (caps, structure, features);
767 gst_structure_free (structure);
769 gst_caps_features_free (features);
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 GST_CAPS_LEN (caps);
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().
807 * You do not need to free or unref the structure returned, it
808 * belongs to the #GstCaps.
810 * Returns: (transfer none): a pointer to the #GstStructure corresponding
814 gst_caps_get_structure (const GstCaps * caps, guint index)
816 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
817 g_return_val_if_fail (index < GST_CAPS_LEN (caps), NULL);
819 return gst_caps_get_structure_unchecked (caps, index);
823 * gst_caps_get_features:
825 * @index: the index of the structure
827 * Finds the features in @caps that has the index @index, and
830 * WARNING: This function takes a const GstCaps *, but returns a
831 * non-const GstCapsFeatures *. This is for programming convenience --
832 * the caller should be aware that structures inside a constant
833 * #GstCaps should not be modified. However, if you know the caps
834 * are writable, either because you have just copied them or made
835 * them writable with gst_caps_make_writable(), you may modify the
836 * features returned in the usual way, e.g. with functions like
837 * gst_caps_features_add().
839 * You do not need to free or unref the structure returned, it
840 * belongs to the #GstCaps.
842 * Returns: (transfer none): a pointer to the #GstCapsFeatures corresponding
848 gst_caps_get_features (const GstCaps * caps, guint index)
850 GstCapsFeatures *features;
852 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
853 g_return_val_if_fail (index < GST_CAPS_LEN (caps), NULL);
855 features = gst_caps_get_features_unchecked (caps, index);
857 GstCapsFeatures **storage;
859 /* We have to do some atomic pointer magic here as the caps
860 * might not be writable and someone else calls this function
861 * at the very same time */
862 features = gst_caps_features_copy (GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY);
863 gst_caps_features_set_parent_refcount (features, &GST_CAPS_REFCOUNT (caps));
865 storage = gst_caps_get_features_storage_unchecked (caps, index);
866 if (!g_atomic_pointer_compare_and_exchange (storage, NULL, features)) {
867 /* Someone did the same we just tried in the meantime */
868 gst_caps_features_set_parent_refcount (features, NULL);
869 gst_caps_features_free (features);
871 features = gst_caps_get_features_unchecked (caps, index);
872 g_assert (features != NULL);
880 * gst_caps_set_features:
882 * @index: the index of the structure
883 * @features: (allow-none) (transfer full): the #GstCapsFeatures to set
885 * Sets the #GstCapsFeatures @features for the structure at @index.
890 gst_caps_set_features (GstCaps * caps, guint index, GstCapsFeatures * features)
892 GstCapsFeatures **storage, *old;
894 g_return_if_fail (caps != NULL);
895 g_return_if_fail (index <= gst_caps_get_size (caps));
896 g_return_if_fail (IS_WRITABLE (caps));
898 storage = gst_caps_get_features_storage_unchecked (caps, index);
899 /* Not much problem here as caps are writable */
900 old = g_atomic_pointer_get (storage);
901 g_atomic_pointer_set (storage, features);
904 gst_caps_features_set_parent_refcount (features, &GST_CAPS_REFCOUNT (caps));
907 gst_caps_features_free (old);
912 * @caps: the #GstCaps to copy
913 * @nth: the nth structure to copy
915 * Creates a new #GstCaps and appends a copy of the nth structure
916 * contained in @caps.
918 * Returns: (transfer full): the new #GstCaps
921 gst_caps_copy_nth (const GstCaps * caps, guint nth)
924 GstStructure *structure;
925 GstCapsFeatures *features;
927 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
929 newcaps = gst_caps_new_empty ();
930 GST_CAPS_FLAGS (newcaps) = GST_CAPS_FLAGS (caps);
932 if (G_LIKELY (GST_CAPS_LEN (caps) > nth)) {
933 structure = gst_caps_get_structure_unchecked (caps, nth);
934 features = gst_caps_get_features_unchecked (caps, nth);
935 gst_caps_append_structure_unchecked (newcaps,
936 gst_structure_copy (structure),
937 gst_caps_features_copy_conditional (features));
945 * @caps: (transfer full): the #GstCaps to truncate
947 * Discard all but the first structure from @caps. Useful when
950 * Returns: (transfer full): truncated caps
953 gst_caps_truncate (GstCaps * caps)
957 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
959 i = GST_CAPS_LEN (caps) - 1;
963 caps = gst_caps_make_writable (caps);
965 gst_caps_remove_structure (caps, i--);
971 * gst_caps_set_value:
972 * @caps: a writable caps
973 * @field: name of the field to set
974 * @value: value to set the field to
976 * Sets the given @field on all structures of @caps to the given @value.
977 * This is a convenience function for calling gst_structure_set_value() on
978 * all structures of @caps.
981 gst_caps_set_value (GstCaps * caps, const char *field, const GValue * value)
985 g_return_if_fail (GST_IS_CAPS (caps));
986 g_return_if_fail (IS_WRITABLE (caps));
987 g_return_if_fail (field != NULL);
988 g_return_if_fail (G_IS_VALUE (value));
990 len = GST_CAPS_LEN (caps);
991 for (i = 0; i < len; i++) {
992 GstStructure *structure = gst_caps_get_structure_unchecked (caps, i);
993 gst_structure_set_value (structure, field, value);
998 * gst_caps_set_simple_valist:
999 * @caps: the #GstCaps to set
1000 * @field: first field to set
1001 * @varargs: additional parameters
1003 * Sets fields in a #GstCaps. The arguments must be passed in the same
1004 * manner as gst_structure_set(), and be NULL-terminated.
1007 gst_caps_set_simple_valist (GstCaps * caps, const char *field, va_list varargs)
1009 GValue value = { 0, };
1011 g_return_if_fail (GST_IS_CAPS (caps));
1012 g_return_if_fail (IS_WRITABLE (caps));
1018 type = va_arg (varargs, GType);
1020 G_VALUE_COLLECT_INIT (&value, type, varargs, 0, &err);
1021 if (G_UNLIKELY (err)) {
1022 g_critical ("%s", err);
1026 gst_caps_set_value (caps, field, &value);
1028 g_value_unset (&value);
1030 field = va_arg (varargs, const gchar *);
1035 * gst_caps_set_simple:
1036 * @caps: the #GstCaps to set
1037 * @field: first field to set
1038 * @...: additional parameters
1040 * Sets fields in a #GstCaps. The arguments must be passed in the same
1041 * manner as gst_structure_set(), and be NULL-terminated.
1044 gst_caps_set_simple (GstCaps * caps, const char *field, ...)
1048 g_return_if_fail (GST_IS_CAPS (caps));
1049 g_return_if_fail (IS_WRITABLE (caps));
1051 va_start (var_args, field);
1052 gst_caps_set_simple_valist (caps, field, var_args);
1060 * @caps: the #GstCaps to test
1062 * Determines if @caps represents any media format.
1064 * Returns: TRUE if @caps represents any format.
1067 gst_caps_is_any (const GstCaps * caps)
1069 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1071 return (CAPS_IS_ANY (caps));
1075 * gst_caps_is_empty:
1076 * @caps: the #GstCaps to test
1078 * Determines if @caps represents no media formats.
1080 * Returns: TRUE if @caps represents no formats.
1083 gst_caps_is_empty (const GstCaps * caps)
1085 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1087 if (CAPS_IS_ANY (caps))
1090 return CAPS_IS_EMPTY_SIMPLE (caps);
1094 gst_caps_is_fixed_foreach (GQuark field_id, const GValue * value,
1097 return gst_value_is_fixed (value);
1101 * gst_caps_is_fixed:
1102 * @caps: the #GstCaps to test
1104 * Fixed #GstCaps describe exactly one format, that is, they have exactly
1105 * one structure, and each field in the structure describes a fixed type.
1106 * Examples of non-fixed types are GST_TYPE_INT_RANGE and GST_TYPE_LIST.
1108 * Returns: TRUE if @caps is fixed
1111 gst_caps_is_fixed (const GstCaps * caps)
1113 GstStructure *structure;
1114 GstCapsFeatures *features;
1116 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1118 if (GST_CAPS_LEN (caps) != 1)
1121 features = gst_caps_get_features_unchecked (caps, 0);
1122 if (features && gst_caps_features_is_any (features))
1125 structure = gst_caps_get_structure_unchecked (caps, 0);
1127 return gst_structure_foreach (structure, gst_caps_is_fixed_foreach, NULL);
1131 * gst_caps_is_equal_fixed:
1132 * @caps1: the #GstCaps to test
1133 * @caps2: the #GstCaps to test
1135 * Tests if two #GstCaps are equal. This function only works on fixed
1138 * Returns: TRUE if the arguments represent the same format
1141 gst_caps_is_equal_fixed (const GstCaps * caps1, const GstCaps * caps2)
1143 GstStructure *struct1, *struct2;
1144 GstCapsFeatures *features1, *features2;
1146 g_return_val_if_fail (gst_caps_is_fixed (caps1), FALSE);
1147 g_return_val_if_fail (gst_caps_is_fixed (caps2), FALSE);
1149 struct1 = gst_caps_get_structure_unchecked (caps1, 0);
1150 features1 = gst_caps_get_features_unchecked (caps1, 0);
1152 features1 = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
1153 struct2 = gst_caps_get_structure_unchecked (caps2, 0);
1154 features2 = gst_caps_get_features_unchecked (caps2, 0);
1156 features2 = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
1158 return gst_structure_is_equal (struct1, struct2) &&
1159 gst_caps_features_is_equal (features1, features2);
1163 * gst_caps_is_always_compatible:
1164 * @caps1: the #GstCaps to test
1165 * @caps2: the #GstCaps to test
1167 * A given #GstCaps structure is always compatible with another if
1168 * every media format that is in the first is also contained in the
1169 * second. That is, @caps1 is a subset of @caps2.
1171 * Returns: TRUE if @caps1 is a subset of @caps2.
1174 gst_caps_is_always_compatible (const GstCaps * caps1, const GstCaps * caps2)
1176 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1177 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1179 return gst_caps_is_subset (caps1, caps2);
1183 * gst_caps_is_subset:
1184 * @subset: a #GstCaps
1185 * @superset: a potentially greater #GstCaps
1187 * Checks if all caps represented by @subset are also represented by @superset.
1189 * Returns: %TRUE if @subset is a subset of @superset
1192 gst_caps_is_subset (const GstCaps * subset, const GstCaps * superset)
1194 GstStructure *s1, *s2;
1195 GstCapsFeatures *f1, *f2;
1196 gboolean ret = TRUE;
1199 g_return_val_if_fail (subset != NULL, FALSE);
1200 g_return_val_if_fail (superset != NULL, FALSE);
1202 if (CAPS_IS_EMPTY (subset) || CAPS_IS_ANY (superset))
1204 if (CAPS_IS_ANY (subset) || CAPS_IS_EMPTY (superset))
1207 for (i = GST_CAPS_LEN (subset) - 1; i >= 0; i--) {
1208 for (j = GST_CAPS_LEN (superset) - 1; j >= 0; j--) {
1209 s1 = gst_caps_get_structure_unchecked (subset, i);
1210 f1 = gst_caps_get_features_unchecked (subset, i);
1212 f1 = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
1213 s2 = gst_caps_get_structure_unchecked (superset, j);
1214 f2 = gst_caps_get_features_unchecked (superset, j);
1216 f2 = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
1217 if ((!gst_caps_features_is_any (f1) || gst_caps_features_is_any (f2)) &&
1218 gst_caps_features_is_equal (f1, f2)
1219 && gst_structure_is_subset (s1, s2)) {
1220 /* If we found a superset, continue with the next
1221 * subset structure */
1225 /* If we found no superset for this subset structure
1226 * we return FALSE immediately */
1237 * gst_caps_is_subset_structure:
1239 * @structure: a potential #GstStructure subset of @caps
1241 * Checks if @structure is a subset of @caps. See gst_caps_is_subset()
1242 * for more information.
1244 * Returns: %TRUE if @structure is a subset of @caps
1247 gst_caps_is_subset_structure (const GstCaps * caps,
1248 const GstStructure * structure)
1253 g_return_val_if_fail (caps != NULL, FALSE);
1254 g_return_val_if_fail (structure != NULL, FALSE);
1256 if (CAPS_IS_ANY (caps))
1258 if (CAPS_IS_EMPTY (caps))
1261 for (i = GST_CAPS_LEN (caps) - 1; i >= 0; i--) {
1262 s = gst_caps_get_structure_unchecked (caps, i);
1263 if (gst_structure_is_subset (structure, s)) {
1264 /* If we found a superset return TRUE */
1273 * gst_caps_is_subset_structure_full:
1275 * @structure: a potential #GstStructure subset of @caps
1276 * @features: (allow-none): a #GstCapsFeatures for @structure
1278 * Checks if @structure is a subset of @caps. See gst_caps_is_subset()
1279 * for more information.
1281 * Returns: %TRUE if @structure is a subset of @caps
1286 gst_caps_is_subset_structure_full (const GstCaps * caps,
1287 const GstStructure * structure, const GstCapsFeatures * features)
1293 g_return_val_if_fail (caps != NULL, FALSE);
1294 g_return_val_if_fail (structure != NULL, FALSE);
1296 if (CAPS_IS_ANY (caps))
1298 if (CAPS_IS_EMPTY (caps))
1302 features = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
1304 for (i = GST_CAPS_LEN (caps) - 1; i >= 0; i--) {
1305 s = gst_caps_get_structure_unchecked (caps, i);
1306 f = gst_caps_get_features_unchecked (caps, i);
1308 f = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
1309 if ((!gst_caps_features_is_any (features) || gst_caps_features_is_any (f))
1310 && gst_caps_features_is_equal (features, f)
1311 && gst_structure_is_subset (structure, s)) {
1312 /* If we found a superset return TRUE */
1321 * gst_caps_is_equal:
1322 * @caps1: a #GstCaps
1323 * @caps2: another #GstCaps
1325 * Checks if the given caps represent the same set of caps.
1327 * Returns: TRUE if both caps are equal.
1330 gst_caps_is_equal (const GstCaps * caps1, const GstCaps * caps2)
1332 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1333 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1335 if (G_UNLIKELY (caps1 == caps2))
1338 if (G_UNLIKELY (gst_caps_is_fixed (caps1) && gst_caps_is_fixed (caps2)))
1339 return gst_caps_is_equal_fixed (caps1, caps2);
1341 return gst_caps_is_subset (caps1, caps2) && gst_caps_is_subset (caps2, caps1);
1345 * gst_caps_is_strictly_equal:
1346 * @caps1: a #GstCaps
1347 * @caps2: another #GstCaps
1349 * Checks if the given caps are exactly the same set of caps.
1351 * Returns: TRUE if both caps are strictly equal.
1354 gst_caps_is_strictly_equal (const GstCaps * caps1, const GstCaps * caps2)
1357 GstStructure *s1, *s2;
1358 GstCapsFeatures *f1, *f2;
1360 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1361 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1363 if (G_UNLIKELY (caps1 == caps2))
1366 if (GST_CAPS_LEN (caps1) != GST_CAPS_LEN (caps2))
1369 for (i = 0; i < GST_CAPS_LEN (caps1); i++) {
1370 s1 = gst_caps_get_structure_unchecked (caps1, i);
1371 f1 = gst_caps_get_features_unchecked (caps1, i);
1373 f1 = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
1374 s2 = gst_caps_get_structure_unchecked (caps2, i);
1375 f2 = gst_caps_get_features_unchecked (caps2, i);
1377 f2 = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
1379 if (gst_caps_features_is_any (f1) != gst_caps_features_is_any (f2) ||
1380 !gst_caps_features_is_equal (f1, f2) ||
1381 !gst_structure_is_equal (s1, s2))
1388 /* intersect operation */
1391 * gst_caps_can_intersect:
1392 * @caps1: a #GstCaps to intersect
1393 * @caps2: a #GstCaps to intersect
1395 * Tries intersecting @caps1 and @caps2 and reports whether the result would not
1398 * Returns: %TRUE if intersection would be not empty
1401 gst_caps_can_intersect (const GstCaps * caps1, const GstCaps * caps2)
1403 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1404 guint j, k, len1, len2;
1405 GstStructure *struct1;
1406 GstStructure *struct2;
1407 GstCapsFeatures *features1;
1408 GstCapsFeatures *features2;
1410 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1411 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1413 /* caps are exactly the same pointers */
1414 if (G_UNLIKELY (caps1 == caps2))
1417 /* empty caps on either side, return empty */
1418 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1421 /* one of the caps is any */
1422 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2)))
1425 /* run zigzag on top line then right line, this preserves the caps order
1426 * much better than a simple loop.
1428 * This algorithm zigzags over the caps structures as demonstrated in
1429 * the following matrix:
1432 * +------------- total distance: +-------------
1433 * | 1 2 4 7 0 | 0 1 2 3
1434 * caps2 | 3 5 8 10 1 | 1 2 3 4
1435 * | 6 9 11 12 2 | 2 3 4 5
1437 * First we iterate over the caps1 structures (top line) intersecting
1438 * the structures diagonally down, then we iterate over the caps2
1439 * structures. The result is that the intersections are ordered based on the
1440 * sum of the indexes in the list.
1442 len1 = GST_CAPS_LEN (caps1);
1443 len2 = GST_CAPS_LEN (caps2);
1444 for (i = 0; i < len1 + len2 - 1; i++) {
1445 /* superset index goes from 0 to sgst_caps_structure_intersectuperset->structs->len-1 */
1446 j = MIN (i, len1 - 1);
1447 /* subset index stays 0 until i reaches superset->structs->len, then it
1448 * counts up from 1 to subset->structs->len - 1 */
1449 k = (i > j) ? (i - j) : 0; /* MAX (0, i - j) */
1450 /* now run the diagonal line, end condition is the left or bottom
1453 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1454 features1 = gst_caps_get_features_unchecked (caps1, j);
1456 features1 = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
1457 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1458 features2 = gst_caps_get_features_unchecked (caps2, k);
1460 features2 = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
1461 if (gst_caps_features_is_equal (features1, features2) &&
1462 gst_structure_can_intersect (struct1, struct2)) {
1465 /* move down left */
1467 if (G_UNLIKELY (j == 0))
1468 break; /* so we don't roll back to G_MAXUINT */
1477 gst_caps_intersect_zig_zag (GstCaps * caps1, GstCaps * caps2)
1479 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1480 guint j, k, len1, len2;
1481 GstStructure *struct1;
1482 GstStructure *struct2;
1483 GstCapsFeatures *features1;
1484 GstCapsFeatures *features2;
1486 GstStructure *istruct;
1488 /* caps are exactly the same pointers, just copy one caps */
1489 if (G_UNLIKELY (caps1 == caps2))
1490 return gst_caps_ref (caps1);
1492 /* empty caps on either side, return empty */
1493 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1494 return gst_caps_ref (GST_CAPS_NONE);
1496 /* one of the caps is any, just copy the other caps */
1497 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1498 return gst_caps_ref (caps2);
1500 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1501 return gst_caps_ref (caps1);
1503 dest = gst_caps_new_empty ();
1504 /* run zigzag on top line then right line, this preserves the caps order
1505 * much better than a simple loop.
1507 * This algorithm zigzags over the caps structures as demonstrated in
1508 * the following matrix:
1516 * First we iterate over the caps1 structures (top line) intersecting
1517 * the structures diagonally down, then we iterate over the caps2
1520 len1 = GST_CAPS_LEN (caps1);
1521 len2 = GST_CAPS_LEN (caps2);
1522 for (i = 0; i < len1 + len2 - 1; i++) {
1523 /* caps1 index goes from 0 to GST_CAPS_LEN (caps1)-1 */
1524 j = MIN (i, len1 - 1);
1525 /* caps2 index stays 0 until i reaches GST_CAPS_LEN (caps1), then it counts
1526 * up from 1 to GST_CAPS_LEN (caps2) - 1 */
1527 k = (i > j) ? (i - j) : 0; /* MAX (0, i - j) */
1528 /* now run the diagonal line, end condition is the left or bottom
1531 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1532 features1 = gst_caps_get_features_unchecked (caps1, j);
1534 features1 = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
1535 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1536 features2 = gst_caps_get_features_unchecked (caps2, k);
1538 features2 = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
1539 if (gst_caps_features_is_equal (features1, features2)) {
1540 istruct = gst_structure_intersect (struct1, struct2);
1542 if (gst_caps_features_is_any (features1))
1544 gst_caps_merge_structure_full (dest, istruct,
1545 gst_caps_features_copy_conditional (features2));
1548 gst_caps_merge_structure_full (dest, istruct,
1549 gst_caps_features_copy_conditional (features1));
1552 /* move down left */
1554 if (G_UNLIKELY (j == 0))
1555 break; /* so we don't roll back to G_MAXUINT */
1563 * gst_caps_intersect_first:
1564 * @caps1: a #GstCaps to intersect
1565 * @caps2: a #GstCaps to intersect
1567 * Creates a new #GstCaps that contains all the formats that are common
1568 * to both @caps1 and @caps2.
1570 * Unlike @gst_caps_intersect, the returned caps will be ordered in a similar
1571 * fashion as @caps1.
1573 * Returns: the new #GstCaps
1576 gst_caps_intersect_first (GstCaps * caps1, GstCaps * caps2)
1579 guint j, len1, len2;
1580 GstStructure *struct1;
1581 GstStructure *struct2;
1582 GstCapsFeatures *features1;
1583 GstCapsFeatures *features2;
1585 GstStructure *istruct;
1587 /* caps are exactly the same pointers, just copy one caps */
1588 if (G_UNLIKELY (caps1 == caps2))
1589 return gst_caps_ref (caps1);
1591 /* empty caps on either side, return empty */
1592 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1593 return gst_caps_ref (GST_CAPS_NONE);
1595 /* one of the caps is any, just copy the other caps */
1596 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1597 return gst_caps_ref (caps2);
1599 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1600 return gst_caps_ref (caps1);
1602 dest = gst_caps_new_empty ();
1603 len1 = GST_CAPS_LEN (caps1);
1604 len2 = GST_CAPS_LEN (caps2);
1605 for (i = 0; i < len1; i++) {
1606 struct1 = gst_caps_get_structure_unchecked (caps1, i);
1607 features1 = gst_caps_get_features_unchecked (caps1, i);
1609 features1 = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
1610 for (j = 0; j < len2; j++) {
1611 struct2 = gst_caps_get_structure_unchecked (caps2, j);
1612 features2 = gst_caps_get_features_unchecked (caps2, j);
1614 features2 = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
1615 if (gst_caps_features_is_equal (features1, features2)) {
1616 istruct = gst_structure_intersect (struct1, struct2);
1618 if (gst_caps_features_is_any (features1))
1620 gst_caps_merge_structure_full (dest, istruct,
1621 gst_caps_features_copy_conditional (features2));
1624 gst_caps_merge_structure_full (dest, istruct,
1625 gst_caps_features_copy_conditional (features1));
1635 * gst_caps_intersect_full:
1636 * @caps1: a #GstCaps to intersect
1637 * @caps2: a #GstCaps to intersect
1638 * @mode: The intersection algorithm/mode to use
1640 * Creates a new #GstCaps that contains all the formats that are common
1641 * to both @caps1 and @caps2, the order is defined by the #GstCapsIntersectMode
1644 * Returns: the new #GstCaps
1647 gst_caps_intersect_full (GstCaps * caps1, GstCaps * caps2,
1648 GstCapsIntersectMode mode)
1650 g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
1651 g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
1654 case GST_CAPS_INTERSECT_FIRST:
1655 return gst_caps_intersect_first (caps1, caps2);
1657 g_warning ("Unknown caps intersect mode: %d", mode);
1659 case GST_CAPS_INTERSECT_ZIG_ZAG:
1660 return gst_caps_intersect_zig_zag (caps1, caps2);
1665 * gst_caps_intersect:
1666 * @caps1: a #GstCaps to intersect
1667 * @caps2: a #GstCaps to intersect
1669 * Creates a new #GstCaps that contains all the formats that are common
1670 * to both @caps1 and @caps2. Defaults to %GST_CAPS_INTERSECT_ZIG_ZAG mode.
1672 * Returns: the new #GstCaps
1675 gst_caps_intersect (GstCaps * caps1, GstCaps * caps2)
1677 return gst_caps_intersect_full (caps1, caps2, GST_CAPS_INTERSECT_ZIG_ZAG);
1680 /* subtract operation */
1684 const GstStructure *subtract_from;
1689 gst_caps_structure_subtract_field (GQuark field_id, const GValue * value,
1692 SubtractionEntry *e = user_data;
1693 GValue subtraction = { 0, };
1694 const GValue *other;
1695 GstStructure *structure;
1697 other = gst_structure_id_get_value (e->subtract_from, field_id);
1703 if (!gst_value_subtract (&subtraction, other, value))
1706 if (gst_value_compare (&subtraction, other) == GST_VALUE_EQUAL) {
1707 g_value_unset (&subtraction);
1710 structure = gst_structure_copy (e->subtract_from);
1711 gst_structure_id_take_value (structure, field_id, &subtraction);
1712 e->put_into = g_slist_prepend (e->put_into, structure);
1718 gst_caps_structure_subtract (GSList ** into, const GstStructure * minuend,
1719 const GstStructure * subtrahend)
1724 e.subtract_from = minuend;
1726 ret = gst_structure_foreach ((GstStructure *) subtrahend,
1727 gst_caps_structure_subtract_field, &e);
1734 for (walk = e.put_into; walk; walk = g_slist_next (walk)) {
1735 gst_structure_free (walk->data);
1737 g_slist_free (e.put_into);
1744 * gst_caps_subtract:
1745 * @minuend: #GstCaps to subtract from
1746 * @subtrahend: #GstCaps to subtract
1748 * Subtracts the @subtrahend from the @minuend.
1749 * <note>This function does not work reliably if optional properties for caps
1750 * are included on one caps and omitted on the other.</note>
1752 * Returns: the resulting caps
1755 gst_caps_subtract (GstCaps * minuend, GstCaps * subtrahend)
1760 GstCapsFeatures *min_f, *sub_f;
1761 GstCaps *dest = NULL, *src;
1763 g_return_val_if_fail (minuend != NULL, NULL);
1764 g_return_val_if_fail (subtrahend != NULL, NULL);
1766 if (CAPS_IS_EMPTY (minuend) || CAPS_IS_ANY (subtrahend)) {
1767 return gst_caps_new_empty ();
1770 if (CAPS_IS_EMPTY_SIMPLE (subtrahend))
1771 return gst_caps_ref (minuend);
1773 /* FIXME: Do we want this here or above?
1774 The reason we need this is that there is no definition about what
1775 ANY means for specific types, so it's not possible to reduce ANY partially
1776 You can only remove everything or nothing and that is done above.
1777 Note: there's a test that checks this behaviour. */
1779 g_return_val_if_fail (!CAPS_IS_ANY (minuend), NULL);
1780 sublen = GST_CAPS_LEN (subtrahend);
1781 g_assert (sublen > 0);
1783 src = _gst_caps_copy (minuend);
1784 for (i = 0; i < sublen; i++) {
1787 sub = gst_caps_get_structure_unchecked (subtrahend, i);
1788 sub_f = gst_caps_get_features_unchecked (subtrahend, i);
1790 sub_f = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
1792 gst_caps_unref (src);
1795 dest = gst_caps_new_empty ();
1796 srclen = GST_CAPS_LEN (src);
1797 for (j = 0; j < srclen; j++) {
1798 min = gst_caps_get_structure_unchecked (src, j);
1799 min_f = gst_caps_get_features_unchecked (src, j);
1801 min_f = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
1803 /* Same reason as above for ANY caps */
1804 g_return_val_if_fail (!gst_caps_features_is_any (min_f), NULL);
1806 if (gst_structure_get_name_id (min) == gst_structure_get_name_id (sub) &&
1807 gst_caps_features_is_equal (min_f, sub_f)) {
1810 if (gst_caps_structure_subtract (&list, min, sub)) {
1813 for (walk = list; walk; walk = g_slist_next (walk)) {
1814 gst_caps_append_structure_unchecked (dest,
1815 (GstStructure *) walk->data,
1816 gst_caps_features_copy_conditional (min_f));
1818 g_slist_free (list);
1820 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min),
1821 gst_caps_features_copy_conditional (min_f));
1824 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min),
1825 gst_caps_features_copy_conditional (min_f));
1829 if (CAPS_IS_EMPTY_SIMPLE (dest)) {
1830 gst_caps_unref (src);
1835 gst_caps_unref (src);
1836 dest = gst_caps_simplify (dest);
1841 /* normalize/simplify operations */
1843 typedef struct _NormalizeForeach
1846 GstStructure *structure;
1847 GstCapsFeatures *features;
1851 gst_caps_normalize_foreach (GQuark field_id, const GValue * value, gpointer ptr)
1853 NormalizeForeach *nf = (NormalizeForeach *) ptr;
1857 if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
1858 guint len = gst_value_list_get_size (value);
1860 for (i = 1; i < len; i++) {
1861 const GValue *v = gst_value_list_get_value (value, i);
1862 GstStructure *structure = gst_structure_copy (nf->structure);
1864 gst_structure_id_set_value (structure, field_id, v);
1865 gst_caps_append_structure_unchecked (nf->caps, structure,
1866 gst_caps_features_copy_conditional (nf->features));
1869 gst_value_init_and_copy (&val, gst_value_list_get_value (value, 0));
1870 gst_structure_id_take_value (nf->structure, field_id, &val);
1878 * gst_caps_normalize:
1879 * @caps: (transfer full): a #GstCaps to normalize
1881 * Returns a #GstCaps that represents the same set of formats as
1882 * @caps, but contains no lists. Each list is expanded into separate
1885 * This function takes ownership of @caps.
1887 * Returns: (transfer full): the normalized #GstCaps
1890 gst_caps_normalize (GstCaps * caps)
1892 NormalizeForeach nf;
1895 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
1897 caps = gst_caps_make_writable (caps);
1900 for (i = 0; i < gst_caps_get_size (nf.caps); i++) {
1901 nf.structure = gst_caps_get_structure_unchecked (nf.caps, i);
1902 nf.features = gst_caps_get_features_unchecked (nf.caps, i);
1903 while (!gst_structure_foreach (nf.structure,
1904 gst_caps_normalize_foreach, &nf));
1911 gst_caps_compare_structures (gconstpointer one, gconstpointer two)
1914 const GstStructure *struct1 = ((const GstCapsArrayElement *) one)->structure;
1915 const GstStructure *struct2 = ((const GstCapsArrayElement *) two)->structure;
1917 /* FIXME: this orders alphabetically, but ordering the quarks might be faster
1918 So what's the best way? */
1919 ret = strcmp (gst_structure_get_name (struct1),
1920 gst_structure_get_name (struct2));
1925 return gst_structure_n_fields (struct2) - gst_structure_n_fields (struct1);
1932 GstStructure *compare;
1936 gst_caps_structure_figure_out_union (GQuark field_id, const GValue * value,
1939 UnionField *u = user_data;
1940 const GValue *val = gst_structure_id_get_value (u->compare, field_id);
1944 g_value_unset (&u->value);
1948 if (gst_value_compare (val, value) == GST_VALUE_EQUAL)
1952 g_value_unset (&u->value);
1957 gst_value_union (&u->value, val, value);
1963 gst_caps_structure_simplify (GstStructure ** result,
1964 GstStructure * simplify, GstStructure * compare)
1967 UnionField field = { 0, {0,}, NULL };
1969 /* try to subtract to get a real subset */
1970 if (gst_caps_structure_subtract (&list, simplify, compare)) {
1971 if (list == NULL) { /* no result */
1974 } else if (list->next == NULL) { /* one result */
1975 *result = list->data;
1976 g_slist_free (list);
1978 } else { /* multiple results */
1979 g_slist_foreach (list, (GFunc) gst_structure_free, NULL);
1980 g_slist_free (list);
1985 /* try to union both structs */
1986 field.compare = compare;
1987 if (gst_structure_foreach (simplify,
1988 gst_caps_structure_figure_out_union, &field)) {
1989 gboolean ret = FALSE;
1991 /* now we know all of simplify's fields are the same in compare
1992 * but at most one field: field.name */
1993 if (G_IS_VALUE (&field.value)) {
1994 if (gst_structure_n_fields (simplify) == gst_structure_n_fields (compare)) {
1995 gst_structure_id_take_value (compare, field.name, &field.value);
1999 g_value_unset (&field.value);
2002 if (gst_structure_n_fields (simplify) <=
2003 gst_structure_n_fields (compare)) {
2004 /* compare is just more specific, will be optimized away later */
2005 /* FIXME: do this here? */
2006 GST_LOG ("found a case that will be optimized later.");
2008 gchar *one = gst_structure_to_string (simplify);
2009 gchar *two = gst_structure_to_string (compare);
2012 ("caps mismatch: structures %s and %s claim to be possible to unify, but aren't",
2024 gst_caps_switch_structures (GstCaps * caps, GstStructure * old,
2025 GstStructure * new, gint i)
2027 gst_structure_set_parent_refcount (old, NULL);
2028 gst_structure_free (old);
2029 gst_structure_set_parent_refcount (new, &GST_CAPS_REFCOUNT (caps));
2030 g_array_index (GST_CAPS_ARRAY (caps), GstCapsArrayElement, i).structure = new;
2034 * gst_caps_simplify:
2035 * @caps: (transfer full): a #GstCaps to simplify
2037 * Converts the given @caps into a representation that represents the
2038 * same set of formats, but in a simpler form. Component structures that are
2039 * identical are merged. Component structures that have values that can be
2040 * merged are also merged.
2042 * This method does not preserve the original order of @caps.
2044 * Returns: The simplified caps.
2047 gst_caps_simplify (GstCaps * caps)
2049 GstStructure *simplify, *compare, *result = NULL;
2050 GstCapsFeatures *simplify_f, *compare_f;
2053 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
2055 start = GST_CAPS_LEN (caps) - 1;
2056 /* one caps, already as simple as can be */
2060 caps = gst_caps_make_writable (caps);
2062 g_array_sort (GST_CAPS_ARRAY (caps), gst_caps_compare_structures);
2064 for (i = start; i >= 0; i--) {
2065 simplify = gst_caps_get_structure_unchecked (caps, i);
2066 simplify_f = gst_caps_get_features_unchecked (caps, i);
2068 simplify_f = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
2069 compare = gst_caps_get_structure_unchecked (caps, start);
2070 compare_f = gst_caps_get_features_unchecked (caps, start);
2072 compare_f = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
2073 if (gst_structure_get_name_id (simplify) !=
2074 gst_structure_get_name_id (compare) ||
2075 !gst_caps_features_is_equal (simplify_f, compare_f))
2077 for (j = start; j >= 0; j--) {
2080 compare = gst_caps_get_structure_unchecked (caps, j);
2081 compare_f = gst_caps_get_features_unchecked (caps, j);
2083 compare_f = GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY;
2084 if (gst_structure_get_name_id (simplify) !=
2085 gst_structure_get_name_id (compare) ||
2086 !gst_caps_features_is_equal (simplify_f, compare_f)) {
2089 if (gst_caps_structure_simplify (&result, simplify, compare)) {
2091 gst_caps_switch_structures (caps, simplify, result, i);
2094 gst_caps_remove_structure (caps, i);
2106 * @caps: (transfer full): a #GstCaps to fixate
2108 * Modifies the given @caps into a representation with only fixed
2109 * values. First the caps will be truncated and then the first structure will be
2110 * fixated with gst_structure_fixate().
2112 * Returns: (transfer full): the fixated caps
2115 gst_caps_fixate (GstCaps * caps)
2120 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
2122 /* default fixation */
2123 caps = gst_caps_truncate (caps);
2124 caps = gst_caps_make_writable (caps);
2125 s = gst_caps_get_structure (caps, 0);
2126 gst_structure_fixate (s);
2128 /* Set features to sysmem if they're still ANY */
2129 f = gst_caps_get_features_unchecked (caps, 0);
2130 if (f && gst_caps_features_is_any (f)) {
2131 f = gst_caps_features_new_empty ();
2132 gst_caps_set_features (caps, 0, f);
2141 * gst_caps_to_string:
2144 * Converts @caps to a string representation. This string representation
2145 * can be converted back to a #GstCaps by gst_caps_from_string().
2147 * For debugging purposes its easier to do something like this:
2149 * GST_LOG ("caps are %" GST_PTR_FORMAT, caps);
2151 * This prints the caps in human readable form.
2153 * The current implementation of serialization will lead to unexpected results
2154 * when there are nested #GstCaps / #GstStructure deeper than one level.
2156 * Returns: (transfer full): a newly allocated string representing @caps.
2159 gst_caps_to_string (const GstCaps * caps)
2161 guint i, slen, clen;
2164 /* NOTE: This function is potentially called by the debug system,
2165 * so any calls to gst_log() (and GST_DEBUG(), GST_LOG(), etc.)
2166 * should be careful to avoid recursion. This includes any functions
2167 * called by gst_caps_to_string. In particular, calls should
2168 * not use the GST_PTR_FORMAT extension. */
2171 return g_strdup ("NULL");
2173 if (CAPS_IS_ANY (caps)) {
2174 return g_strdup ("ANY");
2176 if (CAPS_IS_EMPTY_SIMPLE (caps)) {
2177 return g_strdup ("EMPTY");
2180 /* estimate a rough string length to avoid unnecessary reallocs in GString */
2182 clen = GST_CAPS_LEN (caps);
2183 for (i = 0; i < clen; i++) {
2187 STRUCTURE_ESTIMATED_STRING_LEN (gst_caps_get_structure_unchecked
2189 f = gst_caps_get_features_unchecked (caps, i);
2191 slen += FEATURES_ESTIMATED_STRING_LEN (f);
2194 s = g_string_sized_new (slen);
2195 for (i = 0; i < clen; i++) {
2196 GstStructure *structure;
2197 GstCapsFeatures *features;
2200 /* ';' is now added by gst_structure_to_string */
2201 g_string_append_c (s, ' ');
2204 structure = gst_caps_get_structure_unchecked (caps, i);
2205 features = gst_caps_get_features_unchecked (caps, i);
2207 g_string_append (s, gst_structure_get_name (structure));
2208 if (features && (gst_caps_features_is_any (features)
2209 || !gst_caps_features_is_equal (features,
2210 GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY))) {
2211 g_string_append_c (s, '(');
2212 priv_gst_caps_features_append_to_gstring (features, s);
2213 g_string_append_c (s, ')');
2215 priv_gst_structure_append_to_gstring (structure, s);
2217 if (s->len && s->str[s->len - 1] == ';') {
2218 /* remove latest ';' */
2219 s->str[--s->len] = '\0';
2221 return g_string_free (s, FALSE);
2225 gst_caps_from_string_inplace (GstCaps * caps, const gchar * string)
2227 GstStructure *structure;
2228 gchar *s, *copy, *end, *next, save;
2230 if (strcmp ("ANY", string) == 0) {
2231 GST_CAPS_FLAGS (caps) = GST_CAPS_FLAG_ANY;
2235 if (strcmp ("EMPTY", string) == 0 || strcmp ("NONE", string) == 0) {
2239 copy = s = g_strdup (string);
2241 GstCapsFeatures *features = NULL;
2243 while (g_ascii_isspace (*s))
2249 if (!priv_gst_structure_parse_name (s, &s, &end, &next)) {
2256 structure = gst_structure_new_empty (s);
2259 if (structure == NULL) {
2277 } else if (*end == ')') {
2286 features = gst_caps_features_from_string (s);
2288 gst_structure_free (structure);
2302 if (!priv_gst_structure_parse_fields (s, &s, structure)) {
2303 gst_structure_free (structure);
2309 gst_caps_append_structure_unchecked (caps, structure, features);
2320 * gst_caps_from_string:
2321 * @string: a string to convert to #GstCaps
2323 * Converts @caps from a string representation.
2325 * The current implementation of serialization will lead to unexpected results
2326 * when there are nested #GstCaps / #GstStructure deeper than one level.
2328 * Returns: (transfer full): a newly allocated #GstCaps
2331 gst_caps_from_string (const gchar * string)
2335 g_return_val_if_fail (string, FALSE);
2337 caps = gst_caps_new_empty ();
2338 if (gst_caps_from_string_inplace (caps, string)) {
2341 gst_caps_unref (caps);
2347 gst_caps_transform_to_string (const GValue * src_value, GValue * dest_value)
2349 g_return_if_fail (G_IS_VALUE (src_value));
2350 g_return_if_fail (G_IS_VALUE (dest_value));
2351 g_return_if_fail (G_VALUE_HOLDS (src_value, GST_TYPE_CAPS));
2352 g_return_if_fail (G_VALUE_HOLDS (dest_value, G_TYPE_STRING)
2353 || G_VALUE_HOLDS (dest_value, G_TYPE_POINTER));
2355 g_value_take_string (dest_value,
2356 gst_caps_to_string (gst_value_get_caps (src_value)));