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;
169 caps->flags = GST_CAPS_FLAGS_NONE;
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_TRACE (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_TRACE (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 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_TRACE (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;
495 temp.flags = GST_CAPS_FLAGS_NONE;
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_TRACE (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);
570 * @caps1: the #GstCaps that will be appended to
571 * @caps2: (transfer full): the #GstCaps to append
573 * Appends the structures contained in @caps2 to @caps1. The structures in
574 * @caps2 are not copied -- they are transferred to @caps1, and then @caps2 is
575 * freed. If either caps is ANY, the resulting caps will be ANY.
578 gst_caps_append (GstCaps * caps1, GstCaps * caps2)
580 GstStructure *structure;
583 g_return_if_fail (GST_IS_CAPS (caps1));
584 g_return_if_fail (GST_IS_CAPS (caps2));
585 g_return_if_fail (IS_WRITABLE (caps1));
587 caps2 = gst_caps_make_writable (caps2);
592 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))) {
593 /* FIXME: this leaks */
594 caps1->flags |= GST_CAPS_FLAGS_ANY;
595 for (i = caps2->structs->len - 1; i >= 0; i--) {
596 structure = gst_caps_remove_and_get_structure (caps2, i);
597 gst_structure_free (structure);
600 for (i = caps2->structs->len; i; i--) {
601 structure = gst_caps_remove_and_get_structure (caps2, 0);
602 gst_caps_append_structure_unchecked (caps1, structure);
605 gst_caps_unref (caps2); /* guaranteed to free it */
610 * @caps1: the #GstCaps that will take the new entries
611 * @caps2: (transfer full): the #GstCaps to merge in
613 * Appends the structures contained in @caps2 to @caps1 if they are not yet
614 * expressed by @caps1. The structures in @caps2 are not copied -- they are
615 * transferred to @caps1, and then @caps2 is freed.
616 * If either caps is ANY, the resulting caps will be ANY.
621 gst_caps_merge (GstCaps * caps1, GstCaps * caps2)
623 GstStructure *structure;
626 g_return_if_fail (GST_IS_CAPS (caps1));
627 g_return_if_fail (GST_IS_CAPS (caps2));
628 g_return_if_fail (IS_WRITABLE (caps1));
630 caps2 = gst_caps_make_writable (caps2);
635 if (G_UNLIKELY (CAPS_IS_ANY (caps1))) {
636 for (i = caps2->structs->len - 1; i >= 0; i--) {
637 structure = gst_caps_remove_and_get_structure (caps2, i);
638 gst_structure_free (structure);
640 } else if (G_UNLIKELY (CAPS_IS_ANY (caps2))) {
641 caps1->flags |= GST_CAPS_FLAGS_ANY;
642 for (i = caps1->structs->len - 1; i >= 0; i--) {
643 structure = gst_caps_remove_and_get_structure (caps1, i);
644 gst_structure_free (structure);
647 for (i = caps2->structs->len; i; i--) {
648 structure = gst_caps_remove_and_get_structure (caps2, 0);
649 gst_caps_merge_structure (caps1, structure);
652 GstCaps *com = gst_caps_intersect (caps1, caps2);
653 GstCaps *add = gst_caps_subtract (caps2, com);
655 GST_DEBUG ("common : %d", gst_caps_get_size (com));
656 GST_DEBUG ("adding : %d", gst_caps_get_size (add));
657 gst_caps_append (caps1, add);
658 gst_caps_unref (com);
661 gst_caps_unref (caps2); /* guaranteed to free it */
665 * gst_caps_append_structure:
666 * @caps: the #GstCaps that will be appended to
667 * @structure: (transfer full): the #GstStructure to append
669 * Appends @structure to @caps. The structure is not copied; @caps
670 * becomes the owner of @structure.
673 gst_caps_append_structure (GstCaps * caps, GstStructure * structure)
675 g_return_if_fail (GST_IS_CAPS (caps));
676 g_return_if_fail (IS_WRITABLE (caps));
678 if (G_LIKELY (structure)) {
679 g_return_if_fail (structure->parent_refcount == NULL);
682 STRUCTURE_POISON (structure);
685 gst_caps_append_structure_unchecked (caps, structure);
690 * gst_caps_remove_structure:
691 * @caps: the #GstCaps to remove from
692 * @idx: Index of the structure to remove
694 * removes the stucture with the given index from the list of structures
695 * contained in @caps.
698 gst_caps_remove_structure (GstCaps * caps, guint idx)
700 GstStructure *structure;
702 g_return_if_fail (caps != NULL);
703 g_return_if_fail (idx <= gst_caps_get_size (caps));
704 g_return_if_fail (IS_WRITABLE (caps));
706 structure = gst_caps_remove_and_get_structure (caps, idx);
707 gst_structure_free (structure);
711 * gst_caps_merge_structure:
712 * @caps: the #GstCaps that will the new structure
713 * @structure: (transfer full): the #GstStructure to merge
715 * Appends @structure to @caps if its not already expressed by @caps. The
716 * structure is not copied; @caps becomes the owner of @structure.
719 gst_caps_merge_structure (GstCaps * caps, GstStructure * structure)
721 g_return_if_fail (GST_IS_CAPS (caps));
722 g_return_if_fail (IS_WRITABLE (caps));
724 if (G_LIKELY (structure)) {
725 GstStructure *structure1;
727 gboolean unique = TRUE;
729 g_return_if_fail (structure->parent_refcount == NULL);
732 STRUCTURE_POISON (structure);
735 /* check each structure */
736 for (i = caps->structs->len - 1; i >= 0; i--) {
737 structure1 = gst_caps_get_structure_unchecked (caps, i);
738 /* if structure is a subset of structure1, then skip it */
739 if (gst_structure_is_subset (structure, structure1)) {
745 gst_caps_append_structure_unchecked (caps, structure);
747 gst_structure_free (structure);
756 * Gets the number of structures contained in @caps.
758 * Returns: the number of structures that @caps contains
761 gst_caps_get_size (const GstCaps * caps)
763 g_return_val_if_fail (GST_IS_CAPS (caps), 0);
765 return caps->structs->len;
769 * gst_caps_get_structure:
771 * @index: the index of the structure
773 * Finds the structure in @caps that has the index @index, and
776 * WARNING: This function takes a const GstCaps *, but returns a
777 * non-const GstStructure *. This is for programming convenience --
778 * the caller should be aware that structures inside a constant
779 * #GstCaps should not be modified. However, if you know the caps
780 * are writable, either because you have just copied them or made
781 * them writable with gst_caps_make_writable(), you may modify the
782 * structure returned in the usual way, e.g. with functions like
783 * gst_structure_set().
785 * You do not need to free or unref the structure returned, it
786 * belongs to the #GstCaps.
788 * Returns: (transfer none): a pointer to the #GstStructure corresponding
792 gst_caps_get_structure (const GstCaps * caps, guint index)
794 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
795 g_return_val_if_fail (index < caps->structs->len, NULL);
797 return gst_caps_get_structure_unchecked (caps, index);
802 * @caps: the #GstCaps to copy
803 * @nth: the nth structure to copy
805 * Creates a new #GstCaps and appends a copy of the nth structure
806 * contained in @caps.
808 * Returns: (transfer full): the new #GstCaps
811 gst_caps_copy_nth (const GstCaps * caps, guint nth)
814 GstStructure *structure;
816 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
818 newcaps = gst_caps_new_empty ();
819 newcaps->flags = caps->flags;
821 if (G_LIKELY (caps->structs->len > nth)) {
822 structure = gst_caps_get_structure_unchecked (caps, nth);
823 gst_caps_append_structure_unchecked (newcaps,
824 gst_structure_copy (structure));
832 * @caps: the #GstCaps to truncate
834 * Destructively discard all but the first structure from @caps. Useful when
835 * fixating. @caps must be writable.
838 gst_caps_truncate (GstCaps * caps)
842 g_return_if_fail (GST_IS_CAPS (caps));
843 g_return_if_fail (IS_WRITABLE (caps));
845 i = caps->structs->len - 1;
848 gst_caps_remove_structure (caps, i--);
852 * gst_caps_set_value:
853 * @caps: a writable caps
854 * @field: name of the field to set
855 * @value: value to set the field to
857 * Sets the given @field on all structures of @caps to the given @value.
858 * This is a convenience function for calling gst_structure_set_value() on
859 * all structures of @caps.
864 gst_caps_set_value (GstCaps * caps, const char *field, const GValue * value)
868 g_return_if_fail (GST_IS_CAPS (caps));
869 g_return_if_fail (IS_WRITABLE (caps));
870 g_return_if_fail (field != NULL);
871 g_return_if_fail (G_IS_VALUE (value));
873 len = caps->structs->len;
874 for (i = 0; i < len; i++) {
875 GstStructure *structure = gst_caps_get_structure_unchecked (caps, i);
876 gst_structure_set_value (structure, field, value);
881 * gst_caps_set_simple_valist:
882 * @caps: the #GstCaps to set
883 * @field: first field to set
884 * @varargs: additional parameters
886 * Sets fields in a #GstCaps. The arguments must be passed in the same
887 * manner as gst_structure_set(), and be NULL-terminated.
888 * <note>Prior to GStreamer version 0.10.26, this function failed when
889 * @caps was not simple. If your code needs to work with those versions
890 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
891 * is %TRUE for @caps.</note>
894 gst_caps_set_simple_valist (GstCaps * caps, const char *field, va_list varargs)
896 GValue value = { 0, };
898 g_return_if_fail (GST_IS_CAPS (caps));
899 g_return_if_fail (IS_WRITABLE (caps));
905 type = va_arg (varargs, GType);
907 if (G_UNLIKELY (type == G_TYPE_DATE)) {
908 g_warning ("Don't use G_TYPE_DATE, use GST_TYPE_DATE instead\n");
909 type = GST_TYPE_DATE;
911 G_VALUE_COLLECT_INIT (&value, type, varargs, 0, &err);
912 if (G_UNLIKELY (err)) {
913 g_critical ("%s", err);
917 gst_caps_set_value (caps, field, &value);
919 g_value_unset (&value);
921 field = va_arg (varargs, const gchar *);
926 * gst_caps_set_simple:
927 * @caps: the #GstCaps to set
928 * @field: first field to set
929 * @...: additional parameters
931 * Sets fields in a #GstCaps. The arguments must be passed in the same
932 * manner as gst_structure_set(), and be NULL-terminated.
933 * <note>Prior to GStreamer version 0.10.26, this function failed when
934 * @caps was not simple. If your code needs to work with those versions
935 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
936 * is %TRUE for @caps.</note>
939 gst_caps_set_simple (GstCaps * caps, const char *field, ...)
943 g_return_if_fail (GST_IS_CAPS (caps));
944 g_return_if_fail (IS_WRITABLE (caps));
946 va_start (var_args, field);
947 gst_caps_set_simple_valist (caps, field, var_args);
955 * @caps: the #GstCaps to test
957 * Determines if @caps represents any media format.
959 * Returns: TRUE if @caps represents any format.
962 gst_caps_is_any (const GstCaps * caps)
964 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
966 return (CAPS_IS_ANY (caps));
971 * @caps: the #GstCaps to test
973 * Determines if @caps represents no media formats.
975 * Returns: TRUE if @caps represents no formats.
978 gst_caps_is_empty (const GstCaps * caps)
980 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
982 if (CAPS_IS_ANY (caps))
985 return CAPS_IS_EMPTY_SIMPLE (caps);
989 gst_caps_is_fixed_foreach (GQuark field_id, const GValue * value,
992 return gst_value_is_fixed (value);
997 * @caps: the #GstCaps to test
999 * Fixed #GstCaps describe exactly one format, that is, they have exactly
1000 * one structure, and each field in the structure describes a fixed type.
1001 * Examples of non-fixed types are GST_TYPE_INT_RANGE and GST_TYPE_LIST.
1003 * Returns: TRUE if @caps is fixed
1006 gst_caps_is_fixed (const GstCaps * caps)
1008 GstStructure *structure;
1010 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1012 if (caps->structs->len != 1)
1015 structure = gst_caps_get_structure_unchecked (caps, 0);
1017 return gst_structure_foreach (structure, gst_caps_is_fixed_foreach, NULL);
1021 * gst_caps_is_equal_fixed:
1022 * @caps1: the #GstCaps to test
1023 * @caps2: the #GstCaps to test
1025 * Tests if two #GstCaps are equal. This function only works on fixed
1028 * Returns: TRUE if the arguments represent the same format
1031 gst_caps_is_equal_fixed (const GstCaps * caps1, const GstCaps * caps2)
1033 GstStructure *struct1, *struct2;
1035 g_return_val_if_fail (gst_caps_is_fixed (caps1), FALSE);
1036 g_return_val_if_fail (gst_caps_is_fixed (caps2), FALSE);
1038 struct1 = gst_caps_get_structure_unchecked (caps1, 0);
1039 struct2 = gst_caps_get_structure_unchecked (caps2, 0);
1041 return gst_structure_is_equal (struct1, struct2);
1045 * gst_caps_is_always_compatible:
1046 * @caps1: the #GstCaps to test
1047 * @caps2: the #GstCaps to test
1049 * A given #GstCaps structure is always compatible with another if
1050 * every media format that is in the first is also contained in the
1051 * second. That is, @caps1 is a subset of @caps2.
1053 * Returns: TRUE if @caps1 is a subset of @caps2.
1056 gst_caps_is_always_compatible (const GstCaps * caps1, const GstCaps * caps2)
1058 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1059 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1061 return gst_caps_is_subset (caps1, caps2);
1065 * gst_caps_is_subset:
1066 * @subset: a #GstCaps
1067 * @superset: a potentially greater #GstCaps
1069 * Checks if all caps represented by @subset are also represented by @superset.
1070 * <note>This function does not work reliably if optional properties for caps
1071 * are included on one caps and omitted on the other.</note>
1073 * Returns: %TRUE if @subset is a subset of @superset
1076 gst_caps_is_subset (const GstCaps * subset, const GstCaps * superset)
1078 GstStructure *s1, *s2;
1079 gboolean ret = TRUE;
1082 g_return_val_if_fail (subset != NULL, FALSE);
1083 g_return_val_if_fail (superset != NULL, FALSE);
1085 if (CAPS_IS_EMPTY (subset) || CAPS_IS_ANY (superset))
1087 if (CAPS_IS_ANY (subset) || CAPS_IS_EMPTY (superset))
1090 for (i = subset->structs->len - 1; i >= 0; i--) {
1091 for (j = superset->structs->len - 1; j >= 0; j--) {
1092 s1 = gst_caps_get_structure_unchecked (subset, i);
1093 s2 = gst_caps_get_structure_unchecked (superset, j);
1094 if (gst_structure_is_subset (s1, s2)) {
1095 /* If we found a superset, continue with the next
1096 * subset structure */
1100 /* If we found no superset for this subset structure
1101 * we return FALSE immediately */
1112 * gst_caps_is_subset_structure:
1114 * @structure: a potential #GstStructure subset of @caps
1116 * Checks if @structure is a subset of @caps. See gst_caps_is_subset()
1117 * for more information.
1119 * Returns: %TRUE if @structure is a subset of @caps
1124 gst_caps_is_subset_structure (const GstCaps * caps,
1125 const GstStructure * structure)
1130 g_return_val_if_fail (caps != NULL, FALSE);
1131 g_return_val_if_fail (structure != NULL, FALSE);
1133 if (CAPS_IS_ANY (caps))
1135 if (CAPS_IS_EMPTY (caps))
1138 for (i = caps->structs->len - 1; i >= 0; i--) {
1139 s = gst_caps_get_structure_unchecked (caps, i);
1140 if (gst_structure_is_subset (structure, s)) {
1141 /* If we found a superset return TRUE */
1150 * gst_caps_is_equal:
1151 * @caps1: a #GstCaps
1152 * @caps2: another #GstCaps
1154 * Checks if the given caps represent the same set of caps.
1155 * <note>This function does not work reliably if optional properties for caps
1156 * are included on one caps and omitted on the other.</note>
1158 * This function deals correctly with passing NULL for any of the caps.
1160 * Returns: TRUE if both caps are equal.
1163 gst_caps_is_equal (const GstCaps * caps1, const GstCaps * caps2)
1165 /* FIXME 0.11: NULL pointers are no valid Caps but indicate an error
1166 * So there should be an assertion that caps1 and caps2 != NULL */
1168 /* NULL <-> NULL is allowed here */
1169 if (G_UNLIKELY (caps1 == caps2))
1172 /* one of them NULL => they are different (can't be both NULL because
1173 * we checked that above) */
1174 if (G_UNLIKELY (caps1 == NULL || caps2 == NULL))
1177 if (G_UNLIKELY (gst_caps_is_fixed (caps1) && gst_caps_is_fixed (caps2)))
1178 return gst_caps_is_equal_fixed (caps1, caps2);
1180 return gst_caps_is_subset (caps1, caps2) && gst_caps_is_subset (caps2, caps1);
1183 /* intersect operation */
1186 * gst_caps_can_intersect:
1187 * @caps1: a #GstCaps to intersect
1188 * @caps2: a #GstCaps to intersect
1190 * Tries intersecting @caps1 and @caps2 and reports whether the result would not
1193 * Returns: %TRUE if intersection would be not empty
1198 gst_caps_can_intersect (const GstCaps * caps1, const GstCaps * caps2)
1200 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1201 guint j, k, len1, len2;
1202 GstStructure *struct1;
1203 GstStructure *struct2;
1205 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1206 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1208 /* caps are exactly the same pointers */
1209 if (G_UNLIKELY (caps1 == caps2))
1212 /* empty caps on either side, return empty */
1213 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1216 /* one of the caps is any */
1217 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2)))
1220 /* run zigzag on top line then right line, this preserves the caps order
1221 * much better than a simple loop.
1223 * This algorithm zigzags over the caps structures as demonstrated in
1224 * the folowing matrix:
1227 * +------------- total distance: +-------------
1228 * | 1 2 4 7 0 | 0 1 2 3
1229 * caps2 | 3 5 8 10 1 | 1 2 3 4
1230 * | 6 9 11 12 2 | 2 3 4 5
1232 * First we iterate over the caps1 structures (top line) intersecting
1233 * the structures diagonally down, then we iterate over the caps2
1234 * structures. The result is that the intersections are ordered based on the
1235 * sum of the indexes in the list.
1237 len1 = caps1->structs->len;
1238 len2 = caps2->structs->len;
1239 for (i = 0; i < len1 + len2 - 1; i++) {
1240 /* superset index goes from 0 to sgst_caps_structure_intersectuperset->structs->len-1 */
1241 j = MIN (i, len1 - 1);
1242 /* subset index stays 0 until i reaches superset->structs->len, then it
1243 * counts up from 1 to subset->structs->len - 1 */
1244 k = (i > j) ? (i - j) : 0; /* MAX (0, i - j) */
1246 /* now run the diagonal line, end condition is the left or bottom
1249 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1250 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1252 if (gst_structure_can_intersect (struct1, struct2)) {
1255 /* move down left */
1257 if (G_UNLIKELY (j == 0))
1258 break; /* so we don't roll back to G_MAXUINT */
1266 gst_caps_intersect_zig_zag (const GstCaps * caps1, const GstCaps * caps2)
1268 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1269 guint j, k, len1, len2;
1271 GstStructure *struct1;
1272 GstStructure *struct2;
1274 GstStructure *istruct;
1276 /* caps are exactly the same pointers, just copy one caps */
1277 if (G_UNLIKELY (caps1 == caps2))
1278 return gst_caps_copy (caps1);
1280 /* empty caps on either side, return empty */
1281 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1282 return gst_caps_new_empty ();
1284 /* one of the caps is any, just copy the other caps */
1285 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1286 return gst_caps_copy (caps2);
1287 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1288 return gst_caps_copy (caps1);
1290 dest = gst_caps_new_empty ();
1292 /* run zigzag on top line then right line, this preserves the caps order
1293 * much better than a simple loop.
1295 * This algorithm zigzags over the caps structures as demonstrated in
1296 * the folowing matrix:
1304 * First we iterate over the caps1 structures (top line) intersecting
1305 * the structures diagonally down, then we iterate over the caps2
1308 len1 = caps1->structs->len;
1309 len2 = caps2->structs->len;
1310 for (i = 0; i < len1 + len2 - 1; i++) {
1311 /* caps1 index goes from 0 to caps1->structs->len-1 */
1312 j = MIN (i, len1 - 1);
1313 /* caps2 index stays 0 until i reaches caps1->structs->len, then it counts
1314 * up from 1 to caps2->structs->len - 1 */
1315 k = (i > j) ? (i - j) : 0; /* MAX (0, i - j) */
1317 /* now run the diagonal line, end condition is the left or bottom
1320 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1321 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1323 istruct = gst_structure_intersect (struct1, struct2);
1325 gst_caps_merge_structure (dest, istruct);
1326 /* move down left */
1328 if (G_UNLIKELY (j == 0))
1329 break; /* so we don't roll back to G_MAXUINT */
1337 * gst_caps_intersect_first:
1338 * @caps1: a #GstCaps to intersect
1339 * @caps2: a #GstCaps to intersect
1341 * Creates a new #GstCaps that contains all the formats that are common
1342 * to both @caps1 and @caps2.
1344 * Unlike @gst_caps_intersect, the returned caps will be ordered in a similar
1345 * fashion as @caps1.
1347 * Returns: the new #GstCaps
1350 gst_caps_intersect_first (const GstCaps * caps1, const GstCaps * caps2)
1352 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1353 guint j, len1, len2;
1355 GstStructure *struct1;
1356 GstStructure *struct2;
1358 GstStructure *istruct;
1360 /* caps are exactly the same pointers, just copy one caps */
1361 if (G_UNLIKELY (caps1 == caps2))
1362 return gst_caps_copy (caps1);
1364 /* empty caps on either side, return empty */
1365 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1366 return gst_caps_new_empty ();
1368 /* one of the caps is any, just copy the other caps */
1369 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1370 return gst_caps_copy (caps2);
1371 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1372 return gst_caps_copy (caps1);
1374 dest = gst_caps_new_empty ();
1376 len1 = caps1->structs->len;
1377 len2 = caps2->structs->len;
1378 for (i = 0; i < len1; i++) {
1379 struct1 = gst_caps_get_structure_unchecked (caps1, i);
1380 for (j = 0; j < len2; j++) {
1381 struct2 = gst_caps_get_structure_unchecked (caps2, j);
1382 istruct = gst_structure_intersect (struct1, struct2);
1384 gst_caps_merge_structure (dest, istruct);
1392 * gst_caps_intersect_full:
1393 * @caps1: a #GstCaps to intersect
1394 * @caps2: a #GstCaps to intersect
1395 * @mode: The intersection algorithm/mode to use
1397 * Creates a new #GstCaps that contains all the formats that are common
1398 * to both @caps1 and @caps2, the order is defined by the #GstCapsIntersectMode
1401 * Returns: the new #GstCaps
1405 gst_caps_intersect_full (const GstCaps * caps1, const GstCaps * caps2,
1406 GstCapsIntersectMode mode)
1408 g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
1409 g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
1412 case GST_CAPS_INTERSECT_FIRST:
1413 return gst_caps_intersect_first (caps1, caps2);
1415 g_warning ("Unknown caps intersect mode: %d", mode);
1417 case GST_CAPS_INTERSECT_ZIG_ZAG:
1418 return gst_caps_intersect_zig_zag (caps1, caps2);
1423 * gst_caps_intersect:
1424 * @caps1: a #GstCaps to intersect
1425 * @caps2: a #GstCaps to intersect
1427 * Creates a new #GstCaps that contains all the formats that are common
1428 * to both @caps1 and @caps2. Defaults to %GST_CAPS_INTERSECT_ZIG_ZAG mode.
1430 * Returns: the new #GstCaps
1433 gst_caps_intersect (const GstCaps * caps1, const GstCaps * caps2)
1435 return gst_caps_intersect_full (caps1, caps2, GST_CAPS_INTERSECT_ZIG_ZAG);
1439 /* subtract operation */
1443 const GstStructure *subtract_from;
1449 gst_caps_structure_subtract_field (GQuark field_id, const GValue * value,
1452 SubtractionEntry *e = user_data;
1453 GValue subtraction = { 0, };
1454 const GValue *other;
1455 GstStructure *structure;
1457 other = gst_structure_id_get_value (e->subtract_from, field_id);
1461 if (!gst_value_subtract (&subtraction, other, value))
1463 if (gst_value_compare (&subtraction, other) == GST_VALUE_EQUAL) {
1464 g_value_unset (&subtraction);
1467 structure = gst_structure_copy (e->subtract_from);
1468 gst_structure_id_set_value (structure, field_id, &subtraction);
1469 g_value_unset (&subtraction);
1470 e->put_into = g_slist_prepend (e->put_into, structure);
1476 gst_caps_structure_subtract (GSList ** into, const GstStructure * minuend,
1477 const GstStructure * subtrahend)
1482 e.subtract_from = minuend;
1485 ret = gst_structure_foreach ((GstStructure *) subtrahend,
1486 gst_caps_structure_subtract_field, &e);
1492 for (walk = e.put_into; walk; walk = g_slist_next (walk)) {
1493 gst_structure_free (walk->data);
1495 g_slist_free (e.put_into);
1501 * gst_caps_subtract:
1502 * @minuend: #GstCaps to subtract from
1503 * @subtrahend: #GstCaps to subtract
1505 * Subtracts the @subtrahend from the @minuend.
1506 * <note>This function does not work reliably if optional properties for caps
1507 * are included on one caps and omitted on the other.</note>
1509 * Returns: the resulting caps
1512 gst_caps_subtract (const GstCaps * minuend, const GstCaps * subtrahend)
1517 GstCaps *dest = NULL, *src;
1519 g_return_val_if_fail (minuend != NULL, NULL);
1520 g_return_val_if_fail (subtrahend != NULL, NULL);
1522 if (CAPS_IS_EMPTY (minuend) || CAPS_IS_ANY (subtrahend)) {
1523 return gst_caps_new_empty ();
1525 if (CAPS_IS_EMPTY_SIMPLE (subtrahend))
1526 return gst_caps_copy (minuend);
1528 /* FIXME: Do we want this here or above?
1529 The reason we need this is that there is no definition about what
1530 ANY means for specific types, so it's not possible to reduce ANY partially
1531 You can only remove everything or nothing and that is done above.
1532 Note: there's a test that checks this behaviour. */
1533 g_return_val_if_fail (!CAPS_IS_ANY (minuend), NULL);
1534 sublen = subtrahend->structs->len;
1535 g_assert (sublen > 0);
1537 src = gst_caps_copy (minuend);
1538 for (i = 0; i < sublen; i++) {
1541 sub = gst_caps_get_structure_unchecked (subtrahend, i);
1543 gst_caps_unref (src);
1546 dest = gst_caps_new_empty ();
1547 srclen = src->structs->len;
1548 for (j = 0; j < srclen; j++) {
1549 min = gst_caps_get_structure_unchecked (src, j);
1550 if (gst_structure_get_name_id (min) == gst_structure_get_name_id (sub)) {
1553 if (gst_caps_structure_subtract (&list, min, sub)) {
1556 for (walk = list; walk; walk = g_slist_next (walk)) {
1557 gst_caps_append_structure_unchecked (dest,
1558 (GstStructure *) walk->data);
1560 g_slist_free (list);
1562 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1565 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1568 if (CAPS_IS_EMPTY_SIMPLE (dest)) {
1569 gst_caps_unref (src);
1574 gst_caps_unref (src);
1575 gst_caps_do_simplify (dest);
1579 /* union operation */
1582 static GstStructure *
1583 gst_caps_structure_union (const GstStructure * struct1,
1584 const GstStructure * struct2)
1588 const GstStructureField *field1;
1589 const GstStructureField *field2;
1592 /* FIXME this doesn't actually work */
1594 if (struct1->name != struct2->name)
1597 dest = gst_structure_id_empty_new (struct1->name);
1599 for (i = 0; i < struct1->fields->len; i++) {
1600 GValue dest_value = { 0 };
1602 field1 = GST_STRUCTURE_FIELD (struct1, i);
1603 field2 = gst_structure_id_get_field (struct2, field1->name);
1605 if (field2 == NULL) {
1608 if (gst_value_union (&dest_value, &field1->value, &field2->value)) {
1609 gst_structure_set_value (dest, g_quark_to_string (field1->name),
1612 ret = gst_value_compare (&field1->value, &field2->value);
1623 * @caps1: a #GstCaps to union
1624 * @caps2: a #GstCaps to union
1626 * Creates a new #GstCaps that contains all the formats that are in
1627 * either @caps1 and @caps2.
1629 * Returns: the new #GstCaps
1632 gst_caps_union (const GstCaps * caps1, const GstCaps * caps2)
1637 /* NULL pointers are no correct GstCaps */
1638 g_return_val_if_fail (caps1 != NULL, NULL);
1639 g_return_val_if_fail (caps2 != NULL, NULL);
1641 if (CAPS_IS_EMPTY (caps1))
1642 return gst_caps_copy (caps2);
1644 if (CAPS_IS_EMPTY (caps2))
1645 return gst_caps_copy (caps1);
1647 if (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))
1648 return gst_caps_new_any ();
1650 dest1 = gst_caps_copy (caps1);
1651 dest2 = gst_caps_copy (caps2);
1652 gst_caps_append (dest1, dest2);
1654 gst_caps_do_simplify (dest1);
1658 /* normalize/simplify operations */
1660 typedef struct _NormalizeForeach
1663 GstStructure *structure;
1668 gst_caps_normalize_foreach (GQuark field_id, const GValue * value, gpointer ptr)
1670 NormalizeForeach *nf = (NormalizeForeach *) ptr;
1674 if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
1675 guint len = gst_value_list_get_size (value);
1676 for (i = 1; i < len; i++) {
1677 const GValue *v = gst_value_list_get_value (value, i);
1678 GstStructure *structure = gst_structure_copy (nf->structure);
1680 gst_structure_id_set_value (structure, field_id, v);
1681 gst_caps_append_structure_unchecked (nf->caps, structure);
1684 gst_value_init_and_copy (&val, gst_value_list_get_value (value, 0));
1685 gst_structure_id_set_value (nf->structure, field_id, &val);
1686 g_value_unset (&val);
1694 * gst_caps_normalize:
1695 * @caps: a #GstCaps to normalize
1697 * Creates a new #GstCaps that represents the same set of formats as
1698 * @caps, but contains no lists. Each list is expanded into separate
1701 * Returns: the new #GstCaps
1704 gst_caps_normalize (const GstCaps * caps)
1706 NormalizeForeach nf;
1710 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
1712 newcaps = gst_caps_copy (caps);
1715 for (i = 0; i < gst_caps_get_size (newcaps); i++) {
1716 nf.structure = gst_caps_get_structure_unchecked (newcaps, i);
1718 while (!gst_structure_foreach (nf.structure,
1719 gst_caps_normalize_foreach, &nf));
1726 gst_caps_compare_structures (gconstpointer one, gconstpointer two)
1729 const GstStructure *struct1 = *((const GstStructure **) one);
1730 const GstStructure *struct2 = *((const GstStructure **) two);
1732 /* FIXME: this orders alphabetically, but ordering the quarks might be faster
1733 So what's the best way? */
1734 ret = strcmp (gst_structure_get_name (struct1),
1735 gst_structure_get_name (struct2));
1739 return gst_structure_n_fields (struct2) - gst_structure_n_fields (struct1);
1746 GstStructure *compare;
1751 gst_caps_structure_figure_out_union (GQuark field_id, const GValue * value,
1754 UnionField *u = user_data;
1755 const GValue *val = gst_structure_id_get_value (u->compare, field_id);
1759 g_value_unset (&u->value);
1762 if (gst_value_compare (val, value) == GST_VALUE_EQUAL)
1765 g_value_unset (&u->value);
1769 gst_value_union (&u->value, val, value);
1774 gst_caps_structure_simplify (GstStructure ** result,
1775 const GstStructure * simplify, GstStructure * compare)
1778 UnionField field = { 0, {0,}, NULL };
1780 /* try to subtract to get a real subset */
1781 if (gst_caps_structure_subtract (&list, simplify, compare)) {
1782 if (list == NULL) { /* no result */
1785 } else if (list->next == NULL) { /* one result */
1786 *result = list->data;
1787 g_slist_free (list);
1789 } else { /* multiple results */
1790 g_slist_foreach (list, (GFunc) gst_structure_free, NULL);
1791 g_slist_free (list);
1796 /* try to union both structs */
1797 field.compare = compare;
1798 if (gst_structure_foreach ((GstStructure *) simplify,
1799 gst_caps_structure_figure_out_union, &field)) {
1800 gboolean ret = FALSE;
1802 /* now we know all of simplify's fields are the same in compare
1803 * but at most one field: field.name */
1804 if (G_IS_VALUE (&field.value)) {
1805 if (gst_structure_n_fields (simplify) == gst_structure_n_fields (compare)) {
1806 gst_structure_id_set_value (compare, field.name, &field.value);
1810 g_value_unset (&field.value);
1811 } else if (gst_structure_n_fields (simplify) <=
1812 gst_structure_n_fields (compare)) {
1813 /* compare is just more specific, will be optimized away later */
1814 /* FIXME: do this here? */
1815 GST_LOG ("found a case that will be optimized later.");
1817 gchar *one = gst_structure_to_string (simplify);
1818 gchar *two = gst_structure_to_string (compare);
1821 ("caps mismatch: structures %s and %s claim to be possible to unify, but aren't",
1833 gst_caps_switch_structures (GstCaps * caps, GstStructure * old,
1834 GstStructure * new, gint i)
1836 gst_structure_set_parent_refcount (old, NULL);
1837 gst_structure_free (old);
1838 gst_structure_set_parent_refcount (new, &caps->refcount);
1839 g_ptr_array_index (caps->structs, i) = new;
1843 * gst_caps_do_simplify:
1844 * @caps: a #GstCaps to simplify
1846 * Modifies the given @caps inplace into a representation that represents the
1847 * same set of formats, but in a simpler form. Component structures that are
1848 * identical are merged. Component structures that have values that can be
1849 * merged are also merged.
1851 * Returns: TRUE, if the caps could be simplified
1854 gst_caps_do_simplify (GstCaps * caps)
1856 GstStructure *simplify, *compare, *result = NULL;
1858 gboolean changed = FALSE;
1860 g_return_val_if_fail (caps != NULL, FALSE);
1861 g_return_val_if_fail (IS_WRITABLE (caps), FALSE);
1863 if (gst_caps_get_size (caps) < 2)
1866 g_ptr_array_sort (caps->structs, gst_caps_compare_structures);
1868 start = caps->structs->len - 1;
1869 for (i = caps->structs->len - 1; i >= 0; i--) {
1870 simplify = gst_caps_get_structure_unchecked (caps, i);
1871 if (gst_structure_get_name_id (simplify) !=
1872 gst_structure_get_name_id (gst_caps_get_structure_unchecked (caps,
1875 for (j = start; j >= 0; j--) {
1878 compare = gst_caps_get_structure_unchecked (caps, j);
1879 if (gst_structure_get_name_id (simplify) !=
1880 gst_structure_get_name_id (compare)) {
1883 if (gst_caps_structure_simplify (&result, simplify, compare)) {
1885 gst_caps_switch_structures (caps, simplify, result, i);
1888 gst_caps_remove_structure (caps, i);
1900 /* gst_caps_do_simplify (caps); */
1906 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
1908 * gst_caps_save_thyself:
1909 * @caps: a #GstCaps structure
1910 * @parent: a XML parent node
1912 * Serializes a #GstCaps to XML and adds it as a child node of @parent.
1914 * Returns: a XML node pointer
1917 gst_caps_save_thyself (const GstCaps * caps, xmlNodePtr parent)
1919 char *s = gst_caps_to_string (caps);
1921 xmlNewChild (parent, NULL, (xmlChar *) "caps", (xmlChar *) s);
1927 * gst_caps_load_thyself:
1928 * @parent: a XML node
1930 * Creates a #GstCaps from its XML serialization.
1932 * Returns: a new #GstCaps structure
1935 gst_caps_load_thyself (xmlNodePtr parent)
1937 if (strcmp ("caps", (char *) parent->name) == 0) {
1938 return gst_caps_from_string ((gchar *) xmlNodeGetContent (parent));
1949 * @caps: (inout) (transfer full): a pointer to #GstCaps
1950 * @newcaps: a #GstCaps to replace *caps
1952 * Replaces *caps with @newcaps. Unrefs the #GstCaps in the location
1953 * pointed to by @caps, if applicable, then modifies @caps to point to
1954 * @newcaps. An additional ref on @newcaps is taken.
1956 * This function does not take any locks so you might want to lock
1957 * the object owning @caps pointer.
1960 gst_caps_replace (GstCaps ** caps, GstCaps * newcaps)
1964 g_return_if_fail (caps != NULL);
1968 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p, %p -> %p", caps, oldcaps, newcaps);
1970 if (newcaps != oldcaps) {
1972 gst_caps_ref (newcaps);
1977 gst_caps_unref (oldcaps);
1982 * gst_caps_to_string:
1985 * Converts @caps to a string representation. This string representation
1986 * can be converted back to a #GstCaps by gst_caps_from_string().
1988 * For debugging purposes its easier to do something like this:
1990 * GST_LOG ("caps are %" GST_PTR_FORMAT, caps);
1992 * This prints the caps in human readble form.
1994 * Returns: (transfer full): a newly allocated string representing @caps.
1997 gst_caps_to_string (const GstCaps * caps)
1999 guint i, slen, clen;
2002 /* NOTE: This function is potentially called by the debug system,
2003 * so any calls to gst_log() (and GST_DEBUG(), GST_LOG(), etc.)
2004 * should be careful to avoid recursion. This includes any functions
2005 * called by gst_caps_to_string. In particular, calls should
2006 * not use the GST_PTR_FORMAT extension. */
2009 return g_strdup ("NULL");
2011 if (CAPS_IS_ANY (caps)) {
2012 return g_strdup ("ANY");
2014 if (CAPS_IS_EMPTY_SIMPLE (caps)) {
2015 return g_strdup ("EMPTY");
2018 /* estimate a rough string length to avoid unnecessary reallocs in GString */
2020 clen = caps->structs->len;
2021 for (i = 0; i < clen; i++) {
2023 STRUCTURE_ESTIMATED_STRING_LEN (gst_caps_get_structure_unchecked (caps,
2027 s = g_string_sized_new (slen);
2028 for (i = 0; i < clen; i++) {
2029 GstStructure *structure;
2032 /* ';' is now added by gst_structure_to_string */
2033 g_string_append_c (s, ' ');
2036 structure = gst_caps_get_structure_unchecked (caps, i);
2037 priv_gst_structure_append_to_gstring (structure, s);
2039 if (s->len && s->str[s->len - 1] == ';') {
2040 /* remove latest ';' */
2041 s->str[--s->len] = '\0';
2043 return g_string_free (s, FALSE);
2047 gst_caps_from_string_inplace (GstCaps * caps, const gchar * string)
2049 GstStructure *structure;
2052 if (strcmp ("ANY", string) == 0) {
2053 caps->flags = GST_CAPS_FLAGS_ANY;
2056 if (strcmp ("EMPTY", string) == 0) {
2060 structure = gst_structure_from_string (string, &s);
2061 if (structure == NULL) {
2064 gst_caps_append_structure_unchecked (caps, structure);
2068 while (g_ascii_isspace (*s))
2073 structure = gst_structure_from_string (s, &s);
2074 if (structure == NULL) {
2077 gst_caps_append_structure_unchecked (caps, structure);
2085 * gst_caps_from_string:
2086 * @string: a string to convert to #GstCaps
2088 * Converts @caps from a string representation.
2090 * Returns: (transfer full): a newly allocated #GstCaps
2093 gst_caps_from_string (const gchar * string)
2097 g_return_val_if_fail (string, FALSE);
2099 caps = gst_caps_new_empty ();
2100 if (gst_caps_from_string_inplace (caps, string)) {
2103 gst_caps_unref (caps);
2109 gst_caps_transform_to_string (const GValue * src_value, GValue * dest_value)
2111 g_return_if_fail (G_IS_VALUE (src_value));
2112 g_return_if_fail (G_IS_VALUE (dest_value));
2113 g_return_if_fail (G_VALUE_HOLDS (src_value, GST_TYPE_CAPS));
2114 g_return_if_fail (G_VALUE_HOLDS (dest_value, G_TYPE_STRING)
2115 || G_VALUE_HOLDS (dest_value, G_TYPE_POINTER));
2117 g_value_take_string (dest_value,
2118 gst_caps_to_string (gst_value_get_caps (src_value)));
2122 gst_caps_copy_conditional (GstCaps * src)
2125 return gst_caps_ref (src);