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"
74 #include <gobject/gvaluecollector.h>
76 #ifdef GST_DISABLE_DEPRECATED
77 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
78 #include <libxml/parser.h>
79 xmlNodePtr gst_caps_save_thyself (const GstCaps * caps, xmlNodePtr parent);
80 GstCaps *gst_caps_load_thyself (xmlNodePtr parent);
84 #define DEBUG_REFCOUNT
86 #define CAPS_POISON(caps) G_STMT_START{ \
88 GstCaps *_newcaps = gst_caps_copy (caps); \
89 gst_caps_unref(caps); \
93 #define STRUCTURE_POISON(structure) G_STMT_START{ \
95 GstStructure *_newstruct = gst_structure_copy (structure); \
96 gst_structure_free(structure); \
97 structure = _newstruct; \
100 #define IS_WRITABLE(caps) \
101 (g_atomic_int_get (&(caps)->refcount) == 1)
103 /* same as gst_caps_is_any () */
104 #define CAPS_IS_ANY(caps) \
105 ((caps)->flags & GST_CAPS_FLAGS_ANY)
107 /* same as gst_caps_is_empty () */
108 #define CAPS_IS_EMPTY(caps) \
109 (!CAPS_IS_ANY(caps) && CAPS_IS_EMPTY_SIMPLE(caps))
111 #define CAPS_IS_EMPTY_SIMPLE(caps) \
112 (((caps)->structs == NULL) || ((caps)->structs->len == 0))
114 /* quick way to get a caps structure at an index without doing a type or array
116 #define gst_caps_get_structure_unchecked(caps, index) \
117 ((GstStructure *)g_ptr_array_index ((caps)->structs, (index)))
118 /* quick way to append a structure without checking the args */
119 #define gst_caps_append_structure_unchecked(caps, structure) G_STMT_START{\
120 GstStructure *__s=structure; \
121 gst_structure_set_parent_refcount (__s, &caps->refcount); \
122 g_ptr_array_add (caps->structs, __s); \
125 /* lock to protect multiple invocations of static caps to caps conversion */
126 G_LOCK_DEFINE_STATIC (static_caps_lock);
128 static void gst_caps_transform_to_string (const GValue * src_value,
129 GValue * dest_value);
130 static gboolean gst_caps_from_string_inplace (GstCaps * caps,
131 const gchar * string);
132 static GstCaps *gst_caps_copy_conditional (GstCaps * src);
135 gst_caps_get_type (void)
137 static GType gst_caps_type = 0;
139 if (G_UNLIKELY (gst_caps_type == 0)) {
140 gst_caps_type = g_boxed_type_register_static ("GstCaps",
141 (GBoxedCopyFunc) gst_caps_copy_conditional,
142 (GBoxedFreeFunc) gst_caps_unref);
144 g_value_register_transform_func (gst_caps_type,
145 G_TYPE_STRING, gst_caps_transform_to_string);
148 return gst_caps_type;
151 /* creation/deletion */
154 * gst_caps_new_empty:
156 * Creates a new #GstCaps that is empty. That is, the returned
157 * #GstCaps contains no media formats.
158 * Caller is responsible for unreffing the returned caps.
160 * Returns: (transfer full): the new #GstCaps
163 gst_caps_new_empty (void)
165 GstCaps *caps = g_slice_new (GstCaps);
167 caps->type = GST_TYPE_CAPS;
170 caps->structs = g_ptr_array_new ();
171 /* the 32 has been determined by logging caps sizes in _gst_caps_free
172 * but g_ptr_array uses 16 anyway if it expands once, so this does not help
174 * caps->structs = g_ptr_array_sized_new (32);
177 #ifdef DEBUG_REFCOUNT
178 GST_CAT_LOG (GST_CAT_CAPS, "created caps %p", caps);
187 * Creates a new #GstCaps that indicates that it is compatible with
190 * Returns: (transfer full): the new #GstCaps
193 gst_caps_new_any (void)
195 GstCaps *caps = gst_caps_new_empty ();
197 caps->flags = GST_CAPS_FLAGS_ANY;
203 * gst_caps_new_simple:
204 * @media_type: the media type of the structure
205 * @fieldname: first field to set
206 * @...: additional arguments
208 * Creates a new #GstCaps that contains one #GstStructure. The
209 * structure is defined by the arguments, which have the same format
210 * as gst_structure_new().
211 * Caller is responsible for unreffing the returned caps.
213 * Returns: (transfer full): the new #GstCaps
216 gst_caps_new_simple (const char *media_type, const char *fieldname, ...)
219 GstStructure *structure;
222 caps = gst_caps_new_empty ();
224 va_start (var_args, fieldname);
225 structure = gst_structure_new_valist (media_type, fieldname, var_args);
229 gst_caps_append_structure_unchecked (caps, structure);
231 gst_caps_replace (&caps, NULL);
238 * @struct1: the first structure to add
239 * @...: additional structures to add
241 * Creates a new #GstCaps and adds all the structures listed as
242 * arguments. The list must be NULL-terminated. The structures
243 * are not copied; the returned #GstCaps owns the structures.
245 * Returns: (transfer full): the new #GstCaps
248 gst_caps_new_full (GstStructure * struct1, ...)
253 va_start (var_args, struct1);
254 caps = gst_caps_new_full_valist (struct1, var_args);
261 * gst_caps_new_full_valist:
262 * @structure: the first structure to add
263 * @var_args: additional structures to add
265 * Creates a new #GstCaps and adds all the structures listed as
266 * arguments. The list must be NULL-terminated. The structures
267 * are not copied; the returned #GstCaps owns the structures.
269 * Returns: (transfer full): the new #GstCaps
272 gst_caps_new_full_valist (GstStructure * structure, va_list var_args)
276 caps = gst_caps_new_empty ();
279 gst_caps_append_structure_unchecked (caps, structure);
280 structure = va_arg (var_args, GstStructure *);
288 * @caps: the #GstCaps to copy
290 * Creates a new #GstCaps as a copy of the old @caps. The new caps will have a
291 * refcount of 1, owned by the caller. The structures are copied as well.
293 * Note that this function is the semantic equivalent of a gst_caps_ref()
294 * followed by a gst_caps_make_writable(). If you only want to hold on to a
295 * reference to the data, you should use gst_caps_ref().
297 * When you are finished with the caps, call gst_caps_unref() on it.
299 * Returns: (transfer full): the new #GstCaps
302 gst_caps_copy (const GstCaps * caps)
305 GstStructure *structure;
308 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
310 newcaps = gst_caps_new_empty ();
311 newcaps->flags = caps->flags;
312 n = caps->structs->len;
314 for (i = 0; i < n; i++) {
315 structure = gst_caps_get_structure_unchecked (caps, i);
316 gst_caps_append_structure_unchecked (newcaps,
317 gst_structure_copy (structure));
324 _gst_caps_free (GstCaps * caps)
326 GstStructure *structure;
329 /* The refcount must be 0, but since we're only called by gst_caps_unref,
330 * don't bother testing. */
331 len = caps->structs->len;
332 /* This can be used to get statistics about caps sizes */
333 /*GST_CAT_INFO (GST_CAT_CAPS, "caps size: %d", len); */
334 for (i = 0; i < len; i++) {
335 structure = (GstStructure *) gst_caps_get_structure_unchecked (caps, i);
336 gst_structure_set_parent_refcount (structure, NULL);
337 gst_structure_free (structure);
339 g_ptr_array_free (caps->structs, TRUE);
341 memset (caps, 0xff, sizeof (GstCaps));
344 #ifdef DEBUG_REFCOUNT
345 GST_CAT_LOG (GST_CAT_CAPS, "freeing caps %p", caps);
347 g_slice_free (GstCaps, caps);
351 * gst_caps_make_writable:
352 * @caps: (transfer full): the #GstCaps to make writable
354 * Returns a writable copy of @caps.
356 * If there is only one reference count on @caps, the caller must be the owner,
357 * and so this function will return the caps object unchanged. If on the other
358 * hand there is more than one reference on the object, a new caps object will
359 * be returned. The caller's reference on @caps will be removed, and instead the
360 * caller will own a reference to the returned object.
362 * In short, this function unrefs the caps in the argument and refs the caps
363 * that it returns. Don't access the argument after calling this function. See
364 * also: gst_caps_ref().
366 * Returns: (transfer full): the same #GstCaps object.
369 gst_caps_make_writable (GstCaps * caps)
373 g_return_val_if_fail (caps != NULL, NULL);
375 /* we are the only instance reffing this caps */
376 if (IS_WRITABLE (caps))
380 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy caps");
381 copy = gst_caps_copy (caps);
382 gst_caps_unref (caps);
389 * @caps: the #GstCaps to reference
391 * Add a reference to a #GstCaps object.
393 * From this point on, until the caller calls gst_caps_unref() or
394 * gst_caps_make_writable(), it is guaranteed that the caps object will not
395 * change. This means its structures won't change, etc. To use a #GstCaps
396 * object, you must always have a refcount on it -- either the one made
397 * implicitly by e.g. gst_caps_new_simple(), or via taking one explicitly with
400 * Returns: (transfer full): the same #GstCaps object.
403 gst_caps_ref (GstCaps * caps)
405 g_return_val_if_fail (caps != NULL, NULL);
407 #ifdef DEBUG_REFCOUNT
408 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p %d->%d", caps,
409 GST_CAPS_REFCOUNT_VALUE (caps), GST_CAPS_REFCOUNT_VALUE (caps) + 1);
411 g_return_val_if_fail (GST_CAPS_REFCOUNT_VALUE (caps) > 0, NULL);
413 g_atomic_int_inc (&caps->refcount);
420 * @caps: (transfer full): the #GstCaps to unref
422 * Unref a #GstCaps and and free all its structures and the
423 * structures' values when the refcount reaches 0.
426 gst_caps_unref (GstCaps * caps)
428 g_return_if_fail (caps != NULL);
430 #ifdef DEBUG_REFCOUNT
431 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p %d->%d", caps,
432 GST_CAPS_REFCOUNT_VALUE (caps), GST_CAPS_REFCOUNT_VALUE (caps) - 1);
435 g_return_if_fail (GST_CAPS_REFCOUNT_VALUE (caps) > 0);
437 /* if we ended up with the refcount at zero, free the caps */
438 if (G_UNLIKELY (g_atomic_int_dec_and_test (&caps->refcount)))
439 _gst_caps_free (caps);
443 gst_static_caps_get_type (void)
445 static GType staticcaps_type = 0;
447 if (G_UNLIKELY (staticcaps_type == 0)) {
448 staticcaps_type = g_pointer_type_register_static ("GstStaticCaps");
450 return staticcaps_type;
455 * gst_static_caps_get:
456 * @static_caps: the #GstStaticCaps to convert
458 * Converts a #GstStaticCaps to a #GstCaps.
460 * Returns: (transfer full): a pointer to the #GstCaps. Unref after usage.
461 * Since the core holds an additional ref to the returned caps,
462 * use gst_caps_make_writable() on the returned caps to modify it.
465 gst_static_caps_get (GstStaticCaps * static_caps)
469 g_return_val_if_fail (static_caps != NULL, NULL);
471 caps = (GstCaps *) static_caps;
473 /* refcount is 0 when we need to convert */
474 if (G_UNLIKELY (g_atomic_int_get (&caps->refcount) == 0)) {
478 G_LOCK (static_caps_lock);
479 /* check if other thread already updated */
480 if (G_UNLIKELY (g_atomic_int_get (&caps->refcount) > 0))
483 string = static_caps->string;
485 if (G_UNLIKELY (string == NULL))
488 GST_CAT_LOG (GST_CAT_CAPS, "creating %p", static_caps);
490 /* we construct the caps on the stack, then copy over the struct into our
491 * real caps, refcount last. We do this because we must leave the refcount
492 * of the result caps to 0 so that other threads don't run away with the
493 * caps while we are constructing it. */
494 temp.type = GST_TYPE_CAPS;
496 temp.structs = g_ptr_array_new ();
498 /* initialize the caps to a refcount of 1 so the caps can be writable for
499 * the next statement */
502 /* convert to string */
503 if (G_UNLIKELY (!gst_caps_from_string_inplace (&temp, string)))
504 g_critical ("Could not convert static caps \"%s\"", string);
506 /* now copy stuff over to the real caps. */
507 caps->type = temp.type;
508 caps->flags = temp.flags;
509 caps->structs = temp.structs;
510 /* and bump the refcount so other threads can now read */
511 g_atomic_int_set (&caps->refcount, 1);
513 GST_CAT_LOG (GST_CAT_CAPS, "created %p", static_caps);
515 G_UNLOCK (static_caps_lock);
517 /* ref the caps, makes it not writable */
525 G_UNLOCK (static_caps_lock);
526 g_warning ("static caps %p string is NULL", static_caps);
533 static GstStructure *
534 gst_caps_remove_and_get_structure (GstCaps * caps, guint idx)
536 /* don't use index_fast, gst_caps_do_simplify relies on the order */
537 GstStructure *s = g_ptr_array_remove_index (caps->structs, idx);
539 gst_structure_set_parent_refcount (s, NULL);
544 * gst_caps_steal_structure:
545 * @caps: the #GstCaps to retrieve from
546 * @index: Index of the structure to retrieve
548 * Retrieves the stucture with the given index from the list of structures
549 * contained in @caps. The caller becomes the owner of the returned structure.
551 * Returns: (transfer full): a pointer to the #GstStructure corresponding
557 gst_caps_steal_structure (GstCaps * caps, guint index)
559 g_return_val_if_fail (caps != NULL, NULL);
560 g_return_val_if_fail (IS_WRITABLE (caps), NULL);
562 if (G_UNLIKELY (index >= caps->structs->len))
565 return gst_caps_remove_and_get_structure (caps, index);
569 gst_caps_structure_is_subset_field (GQuark field_id, const GValue * value,
572 GstStructure *subtract_from = user_data;
573 GValue subtraction = { 0, };
576 if (!(other = gst_structure_id_get_value (subtract_from, field_id)))
577 /* field is missing in one set */
580 /* equal values are subset */
581 if (gst_value_compare (other, value) == GST_VALUE_EQUAL)
589 * -> 1 - [1,2] = empty
593 * -> [1,2] - [1,3] = empty
597 * -> {1,3} - {1,2} = 3
600 * First caps subtraction needs to return a non-empty set, second
601 * subtractions needs to give en empty set.
603 if (gst_value_subtract (&subtraction, other, value)) {
604 g_value_unset (&subtraction);
605 /* !empty result, swapping must be empty */
606 if (!gst_value_subtract (&subtraction, value, other))
609 g_value_unset (&subtraction);
615 gst_caps_structure_is_subset (const GstStructure * minuend,
616 const GstStructure * subtrahend)
618 if ((minuend->name != subtrahend->name) ||
619 (gst_structure_n_fields (minuend) !=
620 gst_structure_n_fields (subtrahend))) {
624 return gst_structure_foreach ((GstStructure *) subtrahend,
625 gst_caps_structure_is_subset_field, (gpointer) minuend);
630 * @caps1: the #GstCaps that will be appended to
631 * @caps2: (transfer full): the #GstCaps to append
633 * Appends the structures contained in @caps2 to @caps1. The structures in
634 * @caps2 are not copied -- they are transferred to @caps1, and then @caps2 is
635 * freed. If either caps is ANY, the resulting caps will be ANY.
638 gst_caps_append (GstCaps * caps1, GstCaps * caps2)
640 GstStructure *structure;
643 g_return_if_fail (GST_IS_CAPS (caps1));
644 g_return_if_fail (GST_IS_CAPS (caps2));
645 g_return_if_fail (IS_WRITABLE (caps1));
646 g_return_if_fail (IS_WRITABLE (caps2));
651 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))) {
652 /* FIXME: this leaks */
653 caps1->flags |= GST_CAPS_FLAGS_ANY;
654 for (i = caps2->structs->len - 1; i >= 0; i--) {
655 structure = gst_caps_remove_and_get_structure (caps2, i);
656 gst_structure_free (structure);
659 for (i = caps2->structs->len; i; i--) {
660 structure = gst_caps_remove_and_get_structure (caps2, 0);
661 gst_caps_append_structure_unchecked (caps1, structure);
664 gst_caps_unref (caps2); /* guaranteed to free it */
669 * @caps1: the #GstCaps that will take the new entries
670 * @caps2: (transfer full): the #GstCaps to merge in
672 * Appends the structures contained in @caps2 to @caps1 if they are not yet
673 * expressed by @caps1. The structures in @caps2 are not copied -- they are
674 * transferred to @caps1, and then @caps2 is freed.
675 * If either caps is ANY, the resulting caps will be ANY.
680 gst_caps_merge (GstCaps * caps1, GstCaps * caps2)
682 GstStructure *structure;
685 g_return_if_fail (GST_IS_CAPS (caps1));
686 g_return_if_fail (GST_IS_CAPS (caps2));
687 g_return_if_fail (IS_WRITABLE (caps1));
688 g_return_if_fail (IS_WRITABLE (caps2));
693 if (G_UNLIKELY (CAPS_IS_ANY (caps1))) {
694 for (i = caps2->structs->len - 1; i >= 0; i--) {
695 structure = gst_caps_remove_and_get_structure (caps2, i);
696 gst_structure_free (structure);
698 } else if (G_UNLIKELY (CAPS_IS_ANY (caps2))) {
699 caps1->flags |= GST_CAPS_FLAGS_ANY;
700 for (i = caps1->structs->len - 1; i >= 0; i--) {
701 structure = gst_caps_remove_and_get_structure (caps1, i);
702 gst_structure_free (structure);
705 for (i = caps2->structs->len; i; i--) {
706 structure = gst_caps_remove_and_get_structure (caps2, 0);
707 gst_caps_merge_structure (caps1, structure);
710 GstCaps *com = gst_caps_intersect (caps1, caps2);
711 GstCaps *add = gst_caps_subtract (caps2, com);
713 GST_DEBUG ("common : %d", gst_caps_get_size (com));
714 GST_DEBUG ("adding : %d", gst_caps_get_size (add));
715 gst_caps_append (caps1, add);
716 gst_caps_unref (com);
719 gst_caps_unref (caps2); /* guaranteed to free it */
723 * gst_caps_append_structure:
724 * @caps: the #GstCaps that will be appended to
725 * @structure: (transfer full): the #GstStructure to append
727 * Appends @structure to @caps. The structure is not copied; @caps
728 * becomes the owner of @structure.
731 gst_caps_append_structure (GstCaps * caps, GstStructure * structure)
733 g_return_if_fail (GST_IS_CAPS (caps));
734 g_return_if_fail (IS_WRITABLE (caps));
736 if (G_LIKELY (structure)) {
737 g_return_if_fail (structure->parent_refcount == NULL);
740 STRUCTURE_POISON (structure);
743 gst_caps_append_structure_unchecked (caps, structure);
748 * gst_caps_remove_structure:
749 * @caps: the #GstCaps to remove from
750 * @idx: Index of the structure to remove
752 * removes the stucture with the given index from the list of structures
753 * contained in @caps.
756 gst_caps_remove_structure (GstCaps * caps, guint idx)
758 GstStructure *structure;
760 g_return_if_fail (caps != NULL);
761 g_return_if_fail (idx <= gst_caps_get_size (caps));
762 g_return_if_fail (IS_WRITABLE (caps));
764 structure = gst_caps_remove_and_get_structure (caps, idx);
765 gst_structure_free (structure);
769 * gst_caps_merge_structure:
770 * @caps: the #GstCaps that will the the new structure
771 * @structure: (transfer full): the #GstStructure to merge
773 * Appends @structure to @caps if its not already expressed by @caps. The
774 * structure is not copied; @caps becomes the owner of @structure.
777 gst_caps_merge_structure (GstCaps * caps, GstStructure * structure)
779 g_return_if_fail (GST_IS_CAPS (caps));
780 g_return_if_fail (IS_WRITABLE (caps));
782 if (G_LIKELY (structure)) {
783 GstStructure *structure1;
785 gboolean unique = TRUE;
787 g_return_if_fail (structure->parent_refcount == NULL);
790 STRUCTURE_POISON (structure);
793 /* check each structure */
794 for (i = caps->structs->len - 1; i >= 0; i--) {
795 structure1 = gst_caps_get_structure_unchecked (caps, i);
796 /* if structure is a subset of structure1, then skip it */
797 if (gst_caps_structure_is_subset (structure1, structure)) {
803 gst_caps_append_structure_unchecked (caps, structure);
805 gst_structure_free (structure);
814 * Gets the number of structures contained in @caps.
816 * Returns: the number of structures that @caps contains
819 gst_caps_get_size (const GstCaps * caps)
821 g_return_val_if_fail (GST_IS_CAPS (caps), 0);
823 return caps->structs->len;
827 * gst_caps_get_structure:
829 * @index: the index of the structure
831 * Finds the structure in @caps that has the index @index, and
834 * WARNING: This function takes a const GstCaps *, but returns a
835 * non-const GstStructure *. This is for programming convenience --
836 * the caller should be aware that structures inside a constant
837 * #GstCaps should not be modified. However, if you know the caps
838 * are writable, either because you have just copied them or made
839 * them writable with gst_caps_make_writable(), you may modify the
840 * structure returned in the usual way, e.g. with functions like
841 * gst_structure_set().
843 * You do not need to free or unref the structure returned, it
844 * belongs to the #GstCaps.
846 * Returns: (transfer none): a pointer to the #GstStructure corresponding
850 gst_caps_get_structure (const GstCaps * caps, guint index)
852 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
853 g_return_val_if_fail (index < caps->structs->len, NULL);
855 return gst_caps_get_structure_unchecked (caps, index);
860 * @caps: the #GstCaps to copy
861 * @nth: the nth structure to copy
863 * Creates a new #GstCaps and appends a copy of the nth structure
864 * contained in @caps.
866 * Returns: (transfer full): the new #GstCaps
869 gst_caps_copy_nth (const GstCaps * caps, guint nth)
872 GstStructure *structure;
874 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
876 newcaps = gst_caps_new_empty ();
877 newcaps->flags = caps->flags;
879 if (G_LIKELY (caps->structs->len > nth)) {
880 structure = gst_caps_get_structure_unchecked (caps, nth);
881 gst_caps_append_structure_unchecked (newcaps,
882 gst_structure_copy (structure));
890 * @caps: the #GstCaps to truncate
892 * Destructively discard all but the first structure from @caps. Useful when
893 * fixating. @caps must be writable.
896 gst_caps_truncate (GstCaps * caps)
900 g_return_if_fail (GST_IS_CAPS (caps));
901 g_return_if_fail (IS_WRITABLE (caps));
903 i = caps->structs->len - 1;
906 gst_caps_remove_structure (caps, i--);
910 * gst_caps_set_value:
911 * @caps: a writable caps
912 * @field: name of the field to set
913 * @value: value to set the field to
915 * Sets the given @field on all structures of @caps to the given @value.
916 * This is a convenience function for calling gst_structure_set_value() on
917 * all structures of @caps.
922 gst_caps_set_value (GstCaps * caps, const char *field, const GValue * value)
926 g_return_if_fail (GST_IS_CAPS (caps));
927 g_return_if_fail (IS_WRITABLE (caps));
928 g_return_if_fail (field != NULL);
929 g_return_if_fail (G_IS_VALUE (value));
931 len = caps->structs->len;
932 for (i = 0; i < len; i++) {
933 GstStructure *structure = gst_caps_get_structure_unchecked (caps, i);
934 gst_structure_set_value (structure, field, value);
939 * gst_caps_set_simple_valist:
940 * @caps: the #GstCaps to set
941 * @field: first field to set
942 * @varargs: additional parameters
944 * Sets fields in a #GstCaps. The arguments must be passed in the same
945 * manner as gst_structure_set(), and be NULL-terminated.
946 * <note>Prior to GStreamer version 0.10.26, this function failed when
947 * @caps was not simple. If your code needs to work with those versions
948 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
949 * is %TRUE for @caps.</note>
952 gst_caps_set_simple_valist (GstCaps * caps, const char *field, va_list varargs)
954 GValue value = { 0, };
956 g_return_if_fail (GST_IS_CAPS (caps));
957 g_return_if_fail (IS_WRITABLE (caps));
963 type = va_arg (varargs, GType);
965 if (G_UNLIKELY (type == G_TYPE_DATE)) {
966 g_warning ("Don't use G_TYPE_DATE, use GST_TYPE_DATE instead\n");
967 type = GST_TYPE_DATE;
969 G_VALUE_COLLECT_INIT (&value, type, varargs, 0, &err);
970 if (G_UNLIKELY (err)) {
971 g_critical ("%s", err);
975 gst_caps_set_value (caps, field, &value);
977 g_value_unset (&value);
979 field = va_arg (varargs, const gchar *);
984 * gst_caps_set_simple:
985 * @caps: the #GstCaps to set
986 * @field: first field to set
987 * @...: additional parameters
989 * Sets fields in a #GstCaps. The arguments must be passed in the same
990 * manner as gst_structure_set(), and be NULL-terminated.
991 * <note>Prior to GStreamer version 0.10.26, this function failed when
992 * @caps was not simple. If your code needs to work with those versions
993 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
994 * is %TRUE for @caps.</note>
997 gst_caps_set_simple (GstCaps * caps, const char *field, ...)
1001 g_return_if_fail (GST_IS_CAPS (caps));
1002 g_return_if_fail (IS_WRITABLE (caps));
1004 va_start (var_args, field);
1005 gst_caps_set_simple_valist (caps, field, var_args);
1013 * @caps: the #GstCaps to test
1015 * Determines if @caps represents any media format.
1017 * Returns: TRUE if @caps represents any format.
1020 gst_caps_is_any (const GstCaps * caps)
1022 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1024 return (CAPS_IS_ANY (caps));
1028 * gst_caps_is_empty:
1029 * @caps: the #GstCaps to test
1031 * Determines if @caps represents no media formats.
1033 * Returns: TRUE if @caps represents no formats.
1036 gst_caps_is_empty (const GstCaps * caps)
1038 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1040 if (CAPS_IS_ANY (caps))
1043 return CAPS_IS_EMPTY_SIMPLE (caps);
1047 gst_caps_is_fixed_foreach (GQuark field_id, const GValue * value,
1050 return gst_value_is_fixed (value);
1054 * gst_caps_is_fixed:
1055 * @caps: the #GstCaps to test
1057 * Fixed #GstCaps describe exactly one format, that is, they have exactly
1058 * one structure, and each field in the structure describes a fixed type.
1059 * Examples of non-fixed types are GST_TYPE_INT_RANGE and GST_TYPE_LIST.
1061 * Returns: TRUE if @caps is fixed
1064 gst_caps_is_fixed (const GstCaps * caps)
1066 GstStructure *structure;
1068 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1070 if (caps->structs->len != 1)
1073 structure = gst_caps_get_structure_unchecked (caps, 0);
1075 return gst_structure_foreach (structure, gst_caps_is_fixed_foreach, NULL);
1079 * gst_caps_is_equal_fixed:
1080 * @caps1: the #GstCaps to test
1081 * @caps2: the #GstCaps to test
1083 * Tests if two #GstCaps are equal. This function only works on fixed
1086 * Returns: TRUE if the arguments represent the same format
1089 gst_caps_is_equal_fixed (const GstCaps * caps1, const GstCaps * caps2)
1091 GstStructure *struct1, *struct2;
1093 g_return_val_if_fail (gst_caps_is_fixed (caps1), FALSE);
1094 g_return_val_if_fail (gst_caps_is_fixed (caps2), FALSE);
1096 struct1 = gst_caps_get_structure_unchecked (caps1, 0);
1097 struct2 = gst_caps_get_structure_unchecked (caps2, 0);
1099 return gst_structure_is_equal (struct1, struct2);
1103 * gst_caps_is_always_compatible:
1104 * @caps1: the #GstCaps to test
1105 * @caps2: the #GstCaps to test
1107 * A given #GstCaps structure is always compatible with another if
1108 * every media format that is in the first is also contained in the
1109 * second. That is, @caps1 is a subset of @caps2.
1111 * Returns: TRUE if @caps1 is a subset of @caps2.
1114 gst_caps_is_always_compatible (const GstCaps * caps1, const GstCaps * caps2)
1116 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1117 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1119 return gst_caps_is_subset (caps1, caps2);
1123 * gst_caps_is_subset:
1124 * @subset: a #GstCaps
1125 * @superset: a potentially greater #GstCaps
1127 * Checks if all caps represented by @subset are also represented by @superset.
1128 * <note>This function does not work reliably if optional properties for caps
1129 * are included on one caps and omitted on the other.</note>
1131 * Returns: %TRUE if @subset is a subset of @superset
1134 gst_caps_is_subset (const GstCaps * subset, const GstCaps * superset)
1136 GstStructure *s1, *s2;
1137 gboolean ret = TRUE;
1140 g_return_val_if_fail (subset != NULL, FALSE);
1141 g_return_val_if_fail (superset != NULL, FALSE);
1143 if (CAPS_IS_EMPTY (subset) || CAPS_IS_ANY (superset))
1145 if (CAPS_IS_ANY (subset) || CAPS_IS_EMPTY (superset))
1148 for (i = subset->structs->len - 1; i >= 0; i--) {
1149 for (j = superset->structs->len - 1; j >= 0; j--) {
1150 s1 = gst_caps_get_structure_unchecked (subset, i);
1151 s2 = gst_caps_get_structure_unchecked (superset, j);
1152 if (gst_caps_structure_is_subset (s2, s1)) {
1153 /* If we found a superset, continue with the next
1154 * subset structure */
1158 /* If we found no superset for this subset structure
1159 * we return FALSE immediately */
1170 * gst_caps_is_equal:
1171 * @caps1: a #GstCaps
1172 * @caps2: another #GstCaps
1174 * Checks if the given caps represent the same set of caps.
1175 * <note>This function does not work reliably if optional properties for caps
1176 * are included on one caps and omitted on the other.</note>
1178 * This function deals correctly with passing NULL for any of the caps.
1180 * Returns: TRUE if both caps are equal.
1183 gst_caps_is_equal (const GstCaps * caps1, const GstCaps * caps2)
1185 /* FIXME 0.11: NULL pointers are no valid Caps but indicate an error
1186 * So there should be an assertion that caps1 and caps2 != NULL */
1188 /* NULL <-> NULL is allowed here */
1189 if (G_UNLIKELY (caps1 == caps2))
1192 /* one of them NULL => they are different (can't be both NULL because
1193 * we checked that above) */
1194 if (G_UNLIKELY (caps1 == NULL || caps2 == NULL))
1197 if (G_UNLIKELY (gst_caps_is_fixed (caps1) && gst_caps_is_fixed (caps2)))
1198 return gst_caps_is_equal_fixed (caps1, caps2);
1200 return gst_caps_is_subset (caps1, caps2) && gst_caps_is_subset (caps2, caps1);
1203 /* intersect operation */
1206 * gst_caps_can_intersect:
1207 * @caps1: a #GstCaps to intersect
1208 * @caps2: a #GstCaps to intersect
1210 * Tries intersecting @caps1 and @caps2 and reports whether the result would not
1213 * Returns: %TRUE if intersection would be not empty
1218 gst_caps_can_intersect (const GstCaps * caps1, const GstCaps * caps2)
1220 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1221 guint j, k, len1, len2;
1222 GstStructure *struct1;
1223 GstStructure *struct2;
1225 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1226 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1228 /* caps are exactly the same pointers */
1229 if (G_UNLIKELY (caps1 == caps2))
1232 /* empty caps on either side, return empty */
1233 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1236 /* one of the caps is any */
1237 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2)))
1240 /* run zigzag on top line then right line, this preserves the caps order
1241 * much better than a simple loop.
1243 * This algorithm zigzags over the caps structures as demonstrated in
1244 * the folowing matrix:
1247 * +------------- total distance: +-------------
1248 * | 1 2 4 7 0 | 0 1 2 3
1249 * caps2 | 3 5 8 10 1 | 1 2 3 4
1250 * | 6 9 11 12 2 | 2 3 4 5
1252 * First we iterate over the caps1 structures (top line) intersecting
1253 * the structures diagonally down, then we iterate over the caps2
1254 * structures. The result is that the intersections are ordered based on the
1255 * sum of the indexes in the list.
1257 len1 = caps1->structs->len;
1258 len2 = caps2->structs->len;
1259 for (i = 0; i < len1 + len2 - 1; i++) {
1260 /* superset index goes from 0 to sgst_caps_structure_intersectuperset->structs->len-1 */
1261 j = MIN (i, len1 - 1);
1262 /* subset index stays 0 until i reaches superset->structs->len, then it
1263 * counts up from 1 to subset->structs->len - 1 */
1266 /* now run the diagonal line, end condition is the left or bottom
1269 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1270 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1272 if (gst_structure_can_intersect (struct1, struct2)) {
1275 /* move down left */
1277 if (G_UNLIKELY (j == 0))
1278 break; /* so we don't roll back to G_MAXUINT */
1286 gst_caps_intersect_zig_zag (const GstCaps * caps1, const GstCaps * caps2)
1288 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1289 guint j, k, len1, len2;
1291 GstStructure *struct1;
1292 GstStructure *struct2;
1294 GstStructure *istruct;
1296 /* caps are exactly the same pointers, just copy one caps */
1297 if (G_UNLIKELY (caps1 == caps2))
1298 return gst_caps_copy (caps1);
1300 /* empty caps on either side, return empty */
1301 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1302 return gst_caps_new_empty ();
1304 /* one of the caps is any, just copy the other caps */
1305 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1306 return gst_caps_copy (caps2);
1307 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1308 return gst_caps_copy (caps1);
1310 dest = gst_caps_new_empty ();
1312 /* run zigzag on top line then right line, this preserves the caps order
1313 * much better than a simple loop.
1315 * This algorithm zigzags over the caps structures as demonstrated in
1316 * the folowing matrix:
1324 * First we iterate over the caps1 structures (top line) intersecting
1325 * the structures diagonally down, then we iterate over the caps2
1328 len1 = caps1->structs->len;
1329 len2 = caps2->structs->len;
1330 for (i = 0; i < len1 + len2 - 1; i++) {
1331 /* caps1 index goes from 0 to caps1->structs->len-1 */
1332 j = MIN (i, len1 - 1);
1333 /* caps2 index stays 0 until i reaches caps1->structs->len, then it counts
1334 * up from 1 to caps2->structs->len - 1 */
1337 /* now run the diagonal line, end condition is the left or bottom
1340 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1341 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1343 istruct = gst_structure_intersect (struct1, struct2);
1345 gst_caps_merge_structure (dest, istruct);
1346 /* move down left */
1348 if (G_UNLIKELY (j == 0))
1349 break; /* so we don't roll back to G_MAXUINT */
1357 * gst_caps_intersect_first:
1358 * @caps1: a #GstCaps to intersect
1359 * @caps2: a #GstCaps to intersect
1361 * Creates a new #GstCaps that contains all the formats that are common
1362 * to both @caps1 and @caps2.
1364 * Unlike @gst_caps_intersect, the returned caps will be ordered in a similar
1365 * fashion as @caps1.
1367 * Returns: the new #GstCaps
1370 gst_caps_intersect_first (const GstCaps * caps1, const GstCaps * caps2)
1372 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1373 guint j, len1, len2;
1375 GstStructure *struct1;
1376 GstStructure *struct2;
1378 GstStructure *istruct;
1380 /* caps are exactly the same pointers, just copy one caps */
1381 if (G_UNLIKELY (caps1 == caps2))
1382 return gst_caps_copy (caps1);
1384 /* empty caps on either side, return empty */
1385 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1386 return gst_caps_new_empty ();
1388 /* one of the caps is any, just copy the other caps */
1389 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1390 return gst_caps_copy (caps2);
1391 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1392 return gst_caps_copy (caps1);
1394 dest = gst_caps_new_empty ();
1396 len1 = caps1->structs->len;
1397 len2 = caps2->structs->len;
1398 for (i = 0; i < len1; i++) {
1399 struct1 = gst_caps_get_structure_unchecked (caps1, i);
1400 for (j = 0; j < len2; j++) {
1401 struct2 = gst_caps_get_structure_unchecked (caps2, j);
1402 istruct = gst_structure_intersect (struct1, struct2);
1404 gst_caps_merge_structure (dest, istruct);
1412 * gst_caps_intersect_full:
1413 * @caps1: a #GstCaps to intersect
1414 * @caps2: a #GstCaps to intersect
1415 * @mode: The intersection algorithm/mode to use
1417 * Creates a new #GstCaps that contains all the formats that are common
1418 * to both @caps1 and @caps2, the order is defined by the #GstCapsIntersectMode
1421 * Returns: the new #GstCaps
1425 gst_caps_intersect_full (const GstCaps * caps1, const GstCaps * caps2,
1426 GstCapsIntersectMode mode)
1428 g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
1429 g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
1432 case GST_CAPS_INTERSECT_FIRST:
1433 return gst_caps_intersect_first (caps1, caps2);
1435 g_warning ("Unknown caps intersect mode: %d", mode);
1437 case GST_CAPS_INTERSECT_ZIG_ZAG:
1438 return gst_caps_intersect_zig_zag (caps1, caps2);
1443 * gst_caps_intersect:
1444 * @caps1: a #GstCaps to intersect
1445 * @caps2: a #GstCaps to intersect
1447 * Creates a new #GstCaps that contains all the formats that are common
1448 * to both @caps1 and @caps2. Defaults to %GST_CAPS_INTERSECT_ZIG_ZAG mode.
1450 * Returns: the new #GstCaps
1453 gst_caps_intersect (const GstCaps * caps1, const GstCaps * caps2)
1455 return gst_caps_intersect_full (caps1, caps2, GST_CAPS_INTERSECT_ZIG_ZAG);
1459 /* subtract operation */
1463 const GstStructure *subtract_from;
1469 gst_caps_structure_subtract_field (GQuark field_id, const GValue * value,
1472 SubtractionEntry *e = user_data;
1473 GValue subtraction = { 0, };
1474 const GValue *other;
1475 GstStructure *structure;
1477 other = gst_structure_id_get_value (e->subtract_from, field_id);
1481 if (!gst_value_subtract (&subtraction, other, value))
1483 if (gst_value_compare (&subtraction, other) == GST_VALUE_EQUAL) {
1484 g_value_unset (&subtraction);
1487 structure = gst_structure_copy (e->subtract_from);
1488 gst_structure_id_set_value (structure, field_id, &subtraction);
1489 g_value_unset (&subtraction);
1490 e->put_into = g_slist_prepend (e->put_into, structure);
1496 gst_caps_structure_subtract (GSList ** into, const GstStructure * minuend,
1497 const GstStructure * subtrahend)
1502 e.subtract_from = minuend;
1505 ret = gst_structure_foreach ((GstStructure *) subtrahend,
1506 gst_caps_structure_subtract_field, &e);
1512 for (walk = e.put_into; walk; walk = g_slist_next (walk)) {
1513 gst_structure_free (walk->data);
1515 g_slist_free (e.put_into);
1521 * gst_caps_subtract:
1522 * @minuend: #GstCaps to substract from
1523 * @subtrahend: #GstCaps to substract
1525 * Subtracts the @subtrahend from the @minuend.
1526 * <note>This function does not work reliably if optional properties for caps
1527 * are included on one caps and omitted on the other.</note>
1529 * Returns: the resulting caps
1532 gst_caps_subtract (const GstCaps * minuend, const GstCaps * subtrahend)
1537 GstCaps *dest = NULL, *src;
1539 g_return_val_if_fail (minuend != NULL, NULL);
1540 g_return_val_if_fail (subtrahend != NULL, NULL);
1542 if (CAPS_IS_EMPTY (minuend) || CAPS_IS_ANY (subtrahend)) {
1543 return gst_caps_new_empty ();
1545 if (CAPS_IS_EMPTY_SIMPLE (subtrahend))
1546 return gst_caps_copy (minuend);
1548 /* FIXME: Do we want this here or above?
1549 The reason we need this is that there is no definition about what
1550 ANY means for specific types, so it's not possible to reduce ANY partially
1551 You can only remove everything or nothing and that is done above.
1552 Note: there's a test that checks this behaviour. */
1553 g_return_val_if_fail (!CAPS_IS_ANY (minuend), NULL);
1554 sublen = subtrahend->structs->len;
1555 g_assert (sublen > 0);
1557 src = gst_caps_copy (minuend);
1558 for (i = 0; i < sublen; i++) {
1561 sub = gst_caps_get_structure_unchecked (subtrahend, i);
1563 gst_caps_unref (src);
1566 dest = gst_caps_new_empty ();
1567 srclen = src->structs->len;
1568 for (j = 0; j < srclen; j++) {
1569 min = gst_caps_get_structure_unchecked (src, j);
1570 if (gst_structure_get_name_id (min) == gst_structure_get_name_id (sub)) {
1573 if (gst_caps_structure_subtract (&list, min, sub)) {
1576 for (walk = list; walk; walk = g_slist_next (walk)) {
1577 gst_caps_append_structure_unchecked (dest,
1578 (GstStructure *) walk->data);
1580 g_slist_free (list);
1582 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1585 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1588 if (CAPS_IS_EMPTY_SIMPLE (dest)) {
1589 gst_caps_unref (src);
1594 gst_caps_unref (src);
1595 gst_caps_do_simplify (dest);
1599 /* union operation */
1602 static GstStructure *
1603 gst_caps_structure_union (const GstStructure * struct1,
1604 const GstStructure * struct2)
1608 const GstStructureField *field1;
1609 const GstStructureField *field2;
1612 /* FIXME this doesn't actually work */
1614 if (struct1->name != struct2->name)
1617 dest = gst_structure_id_empty_new (struct1->name);
1619 for (i = 0; i < struct1->fields->len; i++) {
1620 GValue dest_value = { 0 };
1622 field1 = GST_STRUCTURE_FIELD (struct1, i);
1623 field2 = gst_structure_id_get_field (struct2, field1->name);
1625 if (field2 == NULL) {
1628 if (gst_value_union (&dest_value, &field1->value, &field2->value)) {
1629 gst_structure_set_value (dest, g_quark_to_string (field1->name),
1632 ret = gst_value_compare (&field1->value, &field2->value);
1643 * @caps1: a #GstCaps to union
1644 * @caps2: a #GstCaps to union
1646 * Creates a new #GstCaps that contains all the formats that are in
1647 * either @caps1 and @caps2.
1649 * Returns: the new #GstCaps
1652 gst_caps_union (const GstCaps * caps1, const GstCaps * caps2)
1657 /* NULL pointers are no correct GstCaps */
1658 g_return_val_if_fail (caps1 != NULL, NULL);
1659 g_return_val_if_fail (caps2 != NULL, NULL);
1661 if (CAPS_IS_EMPTY (caps1))
1662 return gst_caps_copy (caps2);
1664 if (CAPS_IS_EMPTY (caps2))
1665 return gst_caps_copy (caps1);
1667 if (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))
1668 return gst_caps_new_any ();
1670 dest1 = gst_caps_copy (caps1);
1671 dest2 = gst_caps_copy (caps2);
1672 gst_caps_append (dest1, dest2);
1674 gst_caps_do_simplify (dest1);
1678 /* normalize/simplify operations */
1680 typedef struct _NormalizeForeach
1683 GstStructure *structure;
1688 gst_caps_normalize_foreach (GQuark field_id, const GValue * value, gpointer ptr)
1690 NormalizeForeach *nf = (NormalizeForeach *) ptr;
1694 if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
1695 guint len = gst_value_list_get_size (value);
1696 for (i = 1; i < len; i++) {
1697 const GValue *v = gst_value_list_get_value (value, i);
1698 GstStructure *structure = gst_structure_copy (nf->structure);
1700 gst_structure_id_set_value (structure, field_id, v);
1701 gst_caps_append_structure_unchecked (nf->caps, structure);
1704 gst_value_init_and_copy (&val, gst_value_list_get_value (value, 0));
1705 gst_structure_id_set_value (nf->structure, field_id, &val);
1706 g_value_unset (&val);
1714 * gst_caps_normalize:
1715 * @caps: a #GstCaps to normalize
1717 * Creates a new #GstCaps that represents the same set of formats as
1718 * @caps, but contains no lists. Each list is expanded into separate
1721 * Returns: the new #GstCaps
1724 gst_caps_normalize (const GstCaps * caps)
1726 NormalizeForeach nf;
1730 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
1732 newcaps = gst_caps_copy (caps);
1735 for (i = 0; i < gst_caps_get_size (newcaps); i++) {
1736 nf.structure = gst_caps_get_structure_unchecked (newcaps, i);
1738 while (!gst_structure_foreach (nf.structure,
1739 gst_caps_normalize_foreach, &nf));
1746 gst_caps_compare_structures (gconstpointer one, gconstpointer two)
1749 const GstStructure *struct1 = *((const GstStructure **) one);
1750 const GstStructure *struct2 = *((const GstStructure **) two);
1752 /* FIXME: this orders alphabetically, but ordering the quarks might be faster
1753 So what's the best way? */
1754 ret = strcmp (gst_structure_get_name (struct1),
1755 gst_structure_get_name (struct2));
1759 return gst_structure_n_fields (struct2) - gst_structure_n_fields (struct1);
1766 GstStructure *compare;
1771 gst_caps_structure_figure_out_union (GQuark field_id, const GValue * value,
1774 UnionField *u = user_data;
1775 const GValue *val = gst_structure_id_get_value (u->compare, field_id);
1779 g_value_unset (&u->value);
1782 if (gst_value_compare (val, value) == GST_VALUE_EQUAL)
1785 g_value_unset (&u->value);
1789 gst_value_union (&u->value, val, value);
1794 gst_caps_structure_simplify (GstStructure ** result,
1795 const GstStructure * simplify, GstStructure * compare)
1798 UnionField field = { 0, {0,}, NULL };
1800 /* try to subtract to get a real subset */
1801 if (gst_caps_structure_subtract (&list, simplify, compare)) {
1802 if (list == NULL) { /* no result */
1805 } else if (list->next == NULL) { /* one result */
1806 *result = list->data;
1807 g_slist_free (list);
1809 } else { /* multiple results */
1810 g_slist_foreach (list, (GFunc) gst_structure_free, NULL);
1811 g_slist_free (list);
1816 /* try to union both structs */
1817 field.compare = compare;
1818 if (gst_structure_foreach ((GstStructure *) simplify,
1819 gst_caps_structure_figure_out_union, &field)) {
1820 gboolean ret = FALSE;
1822 /* now we know all of simplify's fields are the same in compare
1823 * but at most one field: field.name */
1824 if (G_IS_VALUE (&field.value)) {
1825 if (gst_structure_n_fields (simplify) == gst_structure_n_fields (compare)) {
1826 gst_structure_id_set_value (compare, field.name, &field.value);
1830 g_value_unset (&field.value);
1831 } else if (gst_structure_n_fields (simplify) <=
1832 gst_structure_n_fields (compare)) {
1833 /* compare is just more specific, will be optimized away later */
1834 /* FIXME: do this here? */
1835 GST_LOG ("found a case that will be optimized later.");
1837 gchar *one = gst_structure_to_string (simplify);
1838 gchar *two = gst_structure_to_string (compare);
1841 ("caps mismatch: structures %s and %s claim to be possible to unify, but aren't",
1853 gst_caps_switch_structures (GstCaps * caps, GstStructure * old,
1854 GstStructure * new, gint i)
1856 gst_structure_set_parent_refcount (old, NULL);
1857 gst_structure_free (old);
1858 gst_structure_set_parent_refcount (new, &caps->refcount);
1859 g_ptr_array_index (caps->structs, i) = new;
1863 * gst_caps_do_simplify:
1864 * @caps: a #GstCaps to simplify
1866 * Modifies the given @caps inplace into a representation that represents the
1867 * same set of formats, but in a simpler form. Component structures that are
1868 * identical are merged. Component structures that have values that can be
1869 * merged are also merged.
1871 * Returns: TRUE, if the caps could be simplified
1874 gst_caps_do_simplify (GstCaps * caps)
1876 GstStructure *simplify, *compare, *result = NULL;
1878 gboolean changed = FALSE;
1880 g_return_val_if_fail (caps != NULL, FALSE);
1881 g_return_val_if_fail (IS_WRITABLE (caps), FALSE);
1883 if (gst_caps_get_size (caps) < 2)
1886 g_ptr_array_sort (caps->structs, gst_caps_compare_structures);
1888 start = caps->structs->len - 1;
1889 for (i = caps->structs->len - 1; i >= 0; i--) {
1890 simplify = gst_caps_get_structure_unchecked (caps, i);
1891 if (gst_structure_get_name_id (simplify) !=
1892 gst_structure_get_name_id (gst_caps_get_structure_unchecked (caps,
1895 for (j = start; j >= 0; j--) {
1898 compare = gst_caps_get_structure_unchecked (caps, j);
1899 if (gst_structure_get_name_id (simplify) !=
1900 gst_structure_get_name_id (compare)) {
1903 if (gst_caps_structure_simplify (&result, simplify, compare)) {
1905 gst_caps_switch_structures (caps, simplify, result, i);
1908 gst_caps_remove_structure (caps, i);
1920 /* gst_caps_do_simplify (caps); */
1926 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
1928 * gst_caps_save_thyself:
1929 * @caps: a #GstCaps structure
1930 * @parent: a XML parent node
1932 * Serializes a #GstCaps to XML and adds it as a child node of @parent.
1934 * Returns: a XML node pointer
1937 gst_caps_save_thyself (const GstCaps * caps, xmlNodePtr parent)
1939 char *s = gst_caps_to_string (caps);
1941 xmlNewChild (parent, NULL, (xmlChar *) "caps", (xmlChar *) s);
1947 * gst_caps_load_thyself:
1948 * @parent: a XML node
1950 * Creates a #GstCaps from its XML serialization.
1952 * Returns: a new #GstCaps structure
1955 gst_caps_load_thyself (xmlNodePtr parent)
1957 if (strcmp ("caps", (char *) parent->name) == 0) {
1958 return gst_caps_from_string ((gchar *) xmlNodeGetContent (parent));
1969 * @caps: (inout) (transfer full): a pointer to #GstCaps
1970 * @newcaps: a #GstCaps to replace *caps
1972 * Replaces *caps with @newcaps. Unrefs the #GstCaps in the location
1973 * pointed to by @caps, if applicable, then modifies @caps to point to
1974 * @newcaps. An additional ref on @newcaps is taken.
1976 * This function does not take any locks so you might want to lock
1977 * the object owning @caps pointer.
1980 gst_caps_replace (GstCaps ** caps, GstCaps * newcaps)
1984 g_return_if_fail (caps != NULL);
1988 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p, %p -> %p", caps, oldcaps, newcaps);
1990 if (newcaps != oldcaps) {
1992 gst_caps_ref (newcaps);
1997 gst_caps_unref (oldcaps);
2002 * gst_caps_to_string:
2005 * Converts @caps to a string representation. This string representation
2006 * can be converted back to a #GstCaps by gst_caps_from_string().
2008 * For debugging purposes its easier to do something like this:
2010 * GST_LOG ("caps are %" GST_PTR_FORMAT, caps);
2012 * This prints the caps in human readble form.
2014 * Returns: (transfer full): a newly allocated string representing @caps.
2017 gst_caps_to_string (const GstCaps * caps)
2019 guint i, slen, clen;
2022 /* NOTE: This function is potentially called by the debug system,
2023 * so any calls to gst_log() (and GST_DEBUG(), GST_LOG(), etc.)
2024 * should be careful to avoid recursion. This includes any functions
2025 * called by gst_caps_to_string. In particular, calls should
2026 * not use the GST_PTR_FORMAT extension. */
2029 return g_strdup ("NULL");
2031 if (CAPS_IS_ANY (caps)) {
2032 return g_strdup ("ANY");
2034 if (CAPS_IS_EMPTY_SIMPLE (caps)) {
2035 return g_strdup ("EMPTY");
2038 /* estimate a rough string length to avoid unnecessary reallocs in GString */
2040 clen = caps->structs->len;
2041 for (i = 0; i < clen; i++) {
2043 STRUCTURE_ESTIMATED_STRING_LEN (gst_caps_get_structure_unchecked (caps,
2047 s = g_string_sized_new (slen);
2048 for (i = 0; i < clen; i++) {
2049 GstStructure *structure;
2052 /* ';' is now added by gst_structure_to_string */
2053 g_string_append_c (s, ' ');
2056 structure = gst_caps_get_structure_unchecked (caps, i);
2057 priv_gst_structure_append_to_gstring (structure, s);
2059 if (s->len && s->str[s->len - 1] == ';') {
2060 /* remove latest ';' */
2061 s->str[--s->len] = '\0';
2063 return g_string_free (s, FALSE);
2067 gst_caps_from_string_inplace (GstCaps * caps, const gchar * string)
2069 GstStructure *structure;
2072 if (strcmp ("ANY", string) == 0) {
2073 caps->flags = GST_CAPS_FLAGS_ANY;
2076 if (strcmp ("EMPTY", string) == 0) {
2080 structure = gst_structure_from_string (string, &s);
2081 if (structure == NULL) {
2084 gst_caps_append_structure_unchecked (caps, structure);
2088 while (g_ascii_isspace (*s))
2093 structure = gst_structure_from_string (s, &s);
2094 if (structure == NULL) {
2097 gst_caps_append_structure_unchecked (caps, structure);
2105 * gst_caps_from_string:
2106 * @string: a string to convert to #GstCaps
2108 * Converts @caps from a string representation.
2110 * Returns: (transfer full): a newly allocated #GstCaps
2113 gst_caps_from_string (const gchar * string)
2117 g_return_val_if_fail (string, FALSE);
2119 caps = gst_caps_new_empty ();
2120 if (gst_caps_from_string_inplace (caps, string)) {
2123 gst_caps_unref (caps);
2129 gst_caps_transform_to_string (const GValue * src_value, GValue * dest_value)
2131 g_return_if_fail (G_IS_VALUE (src_value));
2132 g_return_if_fail (G_IS_VALUE (dest_value));
2133 g_return_if_fail (G_VALUE_HOLDS (src_value, GST_TYPE_CAPS));
2134 g_return_if_fail (G_VALUE_HOLDS (dest_value, G_TYPE_STRING)
2135 || G_VALUE_HOLDS (dest_value, G_TYPE_POINTER));
2137 dest_value->data[0].v_pointer =
2138 gst_caps_to_string (src_value->data[0].v_pointer);
2142 gst_caps_copy_conditional (GstCaps * src)
2145 return gst_caps_ref (src);