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);
1184 * gst_caps_is_strictly_equal:
1185 * @caps1: a #GstCaps
1186 * @caps2: another #GstCaps
1188 * Checks if the given caps are exactly the same set of caps.
1190 * This function deals correctly with passing NULL for any of the caps.
1192 * Returns: TRUE if both caps are strictly equal.
1197 gst_caps_is_strictly_equal (const GstCaps * caps1, const GstCaps * caps2)
1200 /* FIXME 0.11: NULL pointers are no valid Caps but indicate an error
1201 * So there should be an assertion that caps1 and caps2 != NULL */
1203 /* NULL <-> NULL is allowed here */
1204 if (G_UNLIKELY (caps1 == caps2))
1207 /* one of them NULL => they are different (can't be both NULL because
1208 * we checked that above) */
1209 if (G_UNLIKELY (caps1 == NULL || caps2 == NULL))
1212 if (caps1->structs->len != caps2->structs->len)
1215 for (i = 0; i < caps1->structs->len; i++) {
1216 if (!gst_structure_is_equal (gst_caps_get_structure_unchecked (caps1, i),
1217 gst_caps_get_structure_unchecked (caps2, i)))
1224 /* intersect operation */
1227 * gst_caps_can_intersect:
1228 * @caps1: a #GstCaps to intersect
1229 * @caps2: a #GstCaps to intersect
1231 * Tries intersecting @caps1 and @caps2 and reports whether the result would not
1234 * Returns: %TRUE if intersection would be not empty
1239 gst_caps_can_intersect (const GstCaps * caps1, const GstCaps * caps2)
1241 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1242 guint j, k, len1, len2;
1243 GstStructure *struct1;
1244 GstStructure *struct2;
1246 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1247 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1249 /* caps are exactly the same pointers */
1250 if (G_UNLIKELY (caps1 == caps2))
1253 /* empty caps on either side, return empty */
1254 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1257 /* one of the caps is any */
1258 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2)))
1261 /* run zigzag on top line then right line, this preserves the caps order
1262 * much better than a simple loop.
1264 * This algorithm zigzags over the caps structures as demonstrated in
1265 * the folowing matrix:
1268 * +------------- total distance: +-------------
1269 * | 1 2 4 7 0 | 0 1 2 3
1270 * caps2 | 3 5 8 10 1 | 1 2 3 4
1271 * | 6 9 11 12 2 | 2 3 4 5
1273 * First we iterate over the caps1 structures (top line) intersecting
1274 * the structures diagonally down, then we iterate over the caps2
1275 * structures. The result is that the intersections are ordered based on the
1276 * sum of the indexes in the list.
1278 len1 = caps1->structs->len;
1279 len2 = caps2->structs->len;
1280 for (i = 0; i < len1 + len2 - 1; i++) {
1281 /* superset index goes from 0 to sgst_caps_structure_intersectuperset->structs->len-1 */
1282 j = MIN (i, len1 - 1);
1283 /* subset index stays 0 until i reaches superset->structs->len, then it
1284 * counts up from 1 to subset->structs->len - 1 */
1285 k = (i > j) ? (i - j) : 0; /* MAX (0, i - j) */
1287 /* now run the diagonal line, end condition is the left or bottom
1290 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1291 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1293 if (gst_structure_can_intersect (struct1, struct2)) {
1296 /* move down left */
1298 if (G_UNLIKELY (j == 0))
1299 break; /* so we don't roll back to G_MAXUINT */
1307 gst_caps_intersect_zig_zag (const GstCaps * caps1, const GstCaps * caps2)
1309 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1310 guint j, k, len1, len2;
1312 GstStructure *struct1;
1313 GstStructure *struct2;
1315 GstStructure *istruct;
1317 /* caps are exactly the same pointers, just copy one caps */
1318 if (G_UNLIKELY (caps1 == caps2))
1319 return gst_caps_copy (caps1);
1321 /* empty caps on either side, return empty */
1322 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1323 return gst_caps_new_empty ();
1325 /* one of the caps is any, just copy the other caps */
1326 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1327 return gst_caps_copy (caps2);
1328 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1329 return gst_caps_copy (caps1);
1331 dest = gst_caps_new_empty ();
1333 /* run zigzag on top line then right line, this preserves the caps order
1334 * much better than a simple loop.
1336 * This algorithm zigzags over the caps structures as demonstrated in
1337 * the folowing matrix:
1345 * First we iterate over the caps1 structures (top line) intersecting
1346 * the structures diagonally down, then we iterate over the caps2
1349 len1 = caps1->structs->len;
1350 len2 = caps2->structs->len;
1351 for (i = 0; i < len1 + len2 - 1; i++) {
1352 /* caps1 index goes from 0 to caps1->structs->len-1 */
1353 j = MIN (i, len1 - 1);
1354 /* caps2 index stays 0 until i reaches caps1->structs->len, then it counts
1355 * up from 1 to caps2->structs->len - 1 */
1356 k = (i > j) ? (i - j) : 0; /* MAX (0, i - j) */
1358 /* now run the diagonal line, end condition is the left or bottom
1361 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1362 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1364 istruct = gst_structure_intersect (struct1, struct2);
1366 gst_caps_merge_structure (dest, istruct);
1367 /* move down left */
1369 if (G_UNLIKELY (j == 0))
1370 break; /* so we don't roll back to G_MAXUINT */
1378 * gst_caps_intersect_first:
1379 * @caps1: a #GstCaps to intersect
1380 * @caps2: a #GstCaps to intersect
1382 * Creates a new #GstCaps that contains all the formats that are common
1383 * to both @caps1 and @caps2.
1385 * Unlike @gst_caps_intersect, the returned caps will be ordered in a similar
1386 * fashion as @caps1.
1388 * Returns: the new #GstCaps
1391 gst_caps_intersect_first (const GstCaps * caps1, const GstCaps * caps2)
1394 guint j, len1, len2;
1396 GstStructure *struct1;
1397 GstStructure *struct2;
1399 GstStructure *istruct;
1401 /* caps are exactly the same pointers, just copy one caps */
1402 if (G_UNLIKELY (caps1 == caps2))
1403 return gst_caps_copy (caps1);
1405 /* empty caps on either side, return empty */
1406 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1407 return gst_caps_new_empty ();
1409 /* one of the caps is any, just copy the other caps */
1410 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1411 return gst_caps_copy (caps2);
1412 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1413 return gst_caps_copy (caps1);
1415 dest = gst_caps_new_empty ();
1417 len1 = caps1->structs->len;
1418 len2 = caps2->structs->len;
1419 for (i = 0; i < len1; i++) {
1420 struct1 = gst_caps_get_structure_unchecked (caps1, i);
1421 for (j = 0; j < len2; j++) {
1422 struct2 = gst_caps_get_structure_unchecked (caps2, j);
1423 istruct = gst_structure_intersect (struct1, struct2);
1425 gst_caps_merge_structure (dest, istruct);
1433 * gst_caps_intersect_full:
1434 * @caps1: a #GstCaps to intersect
1435 * @caps2: a #GstCaps to intersect
1436 * @mode: The intersection algorithm/mode to use
1438 * Creates a new #GstCaps that contains all the formats that are common
1439 * to both @caps1 and @caps2, the order is defined by the #GstCapsIntersectMode
1442 * Returns: the new #GstCaps
1446 gst_caps_intersect_full (const GstCaps * caps1, const GstCaps * caps2,
1447 GstCapsIntersectMode mode)
1449 g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
1450 g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
1453 case GST_CAPS_INTERSECT_FIRST:
1454 return gst_caps_intersect_first (caps1, caps2);
1456 g_warning ("Unknown caps intersect mode: %d", mode);
1458 case GST_CAPS_INTERSECT_ZIG_ZAG:
1459 return gst_caps_intersect_zig_zag (caps1, caps2);
1464 * gst_caps_intersect:
1465 * @caps1: a #GstCaps to intersect
1466 * @caps2: a #GstCaps to intersect
1468 * Creates a new #GstCaps that contains all the formats that are common
1469 * to both @caps1 and @caps2. Defaults to %GST_CAPS_INTERSECT_ZIG_ZAG mode.
1471 * Returns: the new #GstCaps
1474 gst_caps_intersect (const GstCaps * caps1, const GstCaps * caps2)
1476 return gst_caps_intersect_full (caps1, caps2, GST_CAPS_INTERSECT_ZIG_ZAG);
1480 /* subtract operation */
1484 const GstStructure *subtract_from;
1490 gst_caps_structure_subtract_field (GQuark field_id, const GValue * value,
1493 SubtractionEntry *e = user_data;
1494 GValue subtraction = { 0, };
1495 const GValue *other;
1496 GstStructure *structure;
1498 other = gst_structure_id_get_value (e->subtract_from, field_id);
1502 if (!gst_value_subtract (&subtraction, other, value))
1504 if (gst_value_compare (&subtraction, other) == GST_VALUE_EQUAL) {
1505 g_value_unset (&subtraction);
1508 structure = gst_structure_copy (e->subtract_from);
1509 gst_structure_id_set_value (structure, field_id, &subtraction);
1510 g_value_unset (&subtraction);
1511 e->put_into = g_slist_prepend (e->put_into, structure);
1517 gst_caps_structure_subtract (GSList ** into, const GstStructure * minuend,
1518 const GstStructure * subtrahend)
1523 e.subtract_from = minuend;
1526 ret = gst_structure_foreach ((GstStructure *) subtrahend,
1527 gst_caps_structure_subtract_field, &e);
1533 for (walk = e.put_into; walk; walk = g_slist_next (walk)) {
1534 gst_structure_free (walk->data);
1536 g_slist_free (e.put_into);
1542 * gst_caps_subtract:
1543 * @minuend: #GstCaps to subtract from
1544 * @subtrahend: #GstCaps to subtract
1546 * Subtracts the @subtrahend from the @minuend.
1547 * <note>This function does not work reliably if optional properties for caps
1548 * are included on one caps and omitted on the other.</note>
1550 * Returns: the resulting caps
1553 gst_caps_subtract (const GstCaps * minuend, const GstCaps * subtrahend)
1558 GstCaps *dest = NULL, *src;
1560 g_return_val_if_fail (minuend != NULL, NULL);
1561 g_return_val_if_fail (subtrahend != NULL, NULL);
1563 if (CAPS_IS_EMPTY (minuend) || CAPS_IS_ANY (subtrahend)) {
1564 return gst_caps_new_empty ();
1566 if (CAPS_IS_EMPTY_SIMPLE (subtrahend))
1567 return gst_caps_copy (minuend);
1569 /* FIXME: Do we want this here or above?
1570 The reason we need this is that there is no definition about what
1571 ANY means for specific types, so it's not possible to reduce ANY partially
1572 You can only remove everything or nothing and that is done above.
1573 Note: there's a test that checks this behaviour. */
1574 g_return_val_if_fail (!CAPS_IS_ANY (minuend), NULL);
1575 sublen = subtrahend->structs->len;
1576 g_assert (sublen > 0);
1578 src = gst_caps_copy (minuend);
1579 for (i = 0; i < sublen; i++) {
1582 sub = gst_caps_get_structure_unchecked (subtrahend, i);
1584 gst_caps_unref (src);
1587 dest = gst_caps_new_empty ();
1588 srclen = src->structs->len;
1589 for (j = 0; j < srclen; j++) {
1590 min = gst_caps_get_structure_unchecked (src, j);
1591 if (gst_structure_get_name_id (min) == gst_structure_get_name_id (sub)) {
1594 if (gst_caps_structure_subtract (&list, min, sub)) {
1597 for (walk = list; walk; walk = g_slist_next (walk)) {
1598 gst_caps_append_structure_unchecked (dest,
1599 (GstStructure *) walk->data);
1601 g_slist_free (list);
1603 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1606 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1609 if (CAPS_IS_EMPTY_SIMPLE (dest)) {
1610 gst_caps_unref (src);
1615 gst_caps_unref (src);
1616 gst_caps_do_simplify (dest);
1620 /* union operation */
1623 static GstStructure *
1624 gst_caps_structure_union (const GstStructure * struct1,
1625 const GstStructure * struct2)
1629 const GstStructureField *field1;
1630 const GstStructureField *field2;
1633 /* FIXME this doesn't actually work */
1635 if (struct1->name != struct2->name)
1638 dest = gst_structure_id_empty_new (struct1->name);
1640 for (i = 0; i < struct1->fields->len; i++) {
1641 GValue dest_value = { 0 };
1643 field1 = GST_STRUCTURE_FIELD (struct1, i);
1644 field2 = gst_structure_id_get_field (struct2, field1->name);
1646 if (field2 == NULL) {
1649 if (gst_value_union (&dest_value, &field1->value, &field2->value)) {
1650 gst_structure_set_value (dest, g_quark_to_string (field1->name),
1653 ret = gst_value_compare (&field1->value, &field2->value);
1664 * @caps1: a #GstCaps to union
1665 * @caps2: a #GstCaps to union
1667 * Creates a new #GstCaps that contains all the formats that are in
1668 * either @caps1 and @caps2.
1670 * Returns: the new #GstCaps
1673 gst_caps_union (const GstCaps * caps1, const GstCaps * caps2)
1678 /* NULL pointers are no correct GstCaps */
1679 g_return_val_if_fail (caps1 != NULL, NULL);
1680 g_return_val_if_fail (caps2 != NULL, NULL);
1682 if (CAPS_IS_EMPTY (caps1))
1683 return gst_caps_copy (caps2);
1685 if (CAPS_IS_EMPTY (caps2))
1686 return gst_caps_copy (caps1);
1688 if (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))
1689 return gst_caps_new_any ();
1691 dest1 = gst_caps_copy (caps1);
1692 dest2 = gst_caps_copy (caps2);
1693 gst_caps_append (dest1, dest2);
1695 gst_caps_do_simplify (dest1);
1699 /* normalize/simplify operations */
1701 typedef struct _NormalizeForeach
1704 GstStructure *structure;
1709 gst_caps_normalize_foreach (GQuark field_id, const GValue * value, gpointer ptr)
1711 NormalizeForeach *nf = (NormalizeForeach *) ptr;
1715 if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
1716 guint len = gst_value_list_get_size (value);
1717 for (i = 1; i < len; i++) {
1718 const GValue *v = gst_value_list_get_value (value, i);
1719 GstStructure *structure = gst_structure_copy (nf->structure);
1721 gst_structure_id_set_value (structure, field_id, v);
1722 gst_caps_append_structure_unchecked (nf->caps, structure);
1725 gst_value_init_and_copy (&val, gst_value_list_get_value (value, 0));
1726 gst_structure_id_set_value (nf->structure, field_id, &val);
1727 g_value_unset (&val);
1735 * gst_caps_normalize:
1736 * @caps: a #GstCaps to normalize
1738 * Creates a new #GstCaps that represents the same set of formats as
1739 * @caps, but contains no lists. Each list is expanded into separate
1742 * Returns: the new #GstCaps
1745 gst_caps_normalize (const GstCaps * caps)
1747 NormalizeForeach nf;
1751 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
1753 newcaps = gst_caps_copy (caps);
1756 for (i = 0; i < gst_caps_get_size (newcaps); i++) {
1757 nf.structure = gst_caps_get_structure_unchecked (newcaps, i);
1759 while (!gst_structure_foreach (nf.structure,
1760 gst_caps_normalize_foreach, &nf));
1767 gst_caps_compare_structures (gconstpointer one, gconstpointer two)
1770 const GstStructure *struct1 = *((const GstStructure **) one);
1771 const GstStructure *struct2 = *((const GstStructure **) two);
1773 /* FIXME: this orders alphabetically, but ordering the quarks might be faster
1774 So what's the best way? */
1775 ret = strcmp (gst_structure_get_name (struct1),
1776 gst_structure_get_name (struct2));
1780 return gst_structure_n_fields (struct2) - gst_structure_n_fields (struct1);
1787 GstStructure *compare;
1792 gst_caps_structure_figure_out_union (GQuark field_id, const GValue * value,
1795 UnionField *u = user_data;
1796 const GValue *val = gst_structure_id_get_value (u->compare, field_id);
1800 g_value_unset (&u->value);
1803 if (gst_value_compare (val, value) == GST_VALUE_EQUAL)
1806 g_value_unset (&u->value);
1810 gst_value_union (&u->value, val, value);
1815 gst_caps_structure_simplify (GstStructure ** result,
1816 const GstStructure * simplify, GstStructure * compare)
1819 UnionField field = { 0, {0,}, NULL };
1821 /* try to subtract to get a real subset */
1822 if (gst_caps_structure_subtract (&list, simplify, compare)) {
1823 if (list == NULL) { /* no result */
1826 } else if (list->next == NULL) { /* one result */
1827 *result = list->data;
1828 g_slist_free (list);
1830 } else { /* multiple results */
1831 g_slist_foreach (list, (GFunc) gst_structure_free, NULL);
1832 g_slist_free (list);
1837 /* try to union both structs */
1838 field.compare = compare;
1839 if (gst_structure_foreach ((GstStructure *) simplify,
1840 gst_caps_structure_figure_out_union, &field)) {
1841 gboolean ret = FALSE;
1843 /* now we know all of simplify's fields are the same in compare
1844 * but at most one field: field.name */
1845 if (G_IS_VALUE (&field.value)) {
1846 if (gst_structure_n_fields (simplify) == gst_structure_n_fields (compare)) {
1847 gst_structure_id_set_value (compare, field.name, &field.value);
1851 g_value_unset (&field.value);
1852 } else if (gst_structure_n_fields (simplify) <=
1853 gst_structure_n_fields (compare)) {
1854 /* compare is just more specific, will be optimized away later */
1855 /* FIXME: do this here? */
1856 GST_LOG ("found a case that will be optimized later.");
1858 gchar *one = gst_structure_to_string (simplify);
1859 gchar *two = gst_structure_to_string (compare);
1862 ("caps mismatch: structures %s and %s claim to be possible to unify, but aren't",
1874 gst_caps_switch_structures (GstCaps * caps, GstStructure * old,
1875 GstStructure * new, gint i)
1877 gst_structure_set_parent_refcount (old, NULL);
1878 gst_structure_free (old);
1879 gst_structure_set_parent_refcount (new, &caps->refcount);
1880 g_ptr_array_index (caps->structs, i) = new;
1884 * gst_caps_do_simplify:
1885 * @caps: a #GstCaps to simplify
1887 * Modifies the given @caps inplace into a representation that represents the
1888 * same set of formats, but in a simpler form. Component structures that are
1889 * identical are merged. Component structures that have values that can be
1890 * merged are also merged.
1892 * Returns: TRUE, if the caps could be simplified
1895 gst_caps_do_simplify (GstCaps * caps)
1897 GstStructure *simplify, *compare, *result = NULL;
1899 gboolean changed = FALSE;
1901 g_return_val_if_fail (caps != NULL, FALSE);
1902 g_return_val_if_fail (IS_WRITABLE (caps), FALSE);
1904 if (gst_caps_get_size (caps) < 2)
1907 g_ptr_array_sort (caps->structs, gst_caps_compare_structures);
1909 start = caps->structs->len - 1;
1910 for (i = caps->structs->len - 1; i >= 0; i--) {
1911 simplify = gst_caps_get_structure_unchecked (caps, i);
1912 if (gst_structure_get_name_id (simplify) !=
1913 gst_structure_get_name_id (gst_caps_get_structure_unchecked (caps,
1916 for (j = start; j >= 0; j--) {
1919 compare = gst_caps_get_structure_unchecked (caps, j);
1920 if (gst_structure_get_name_id (simplify) !=
1921 gst_structure_get_name_id (compare)) {
1924 if (gst_caps_structure_simplify (&result, simplify, compare)) {
1926 gst_caps_switch_structures (caps, simplify, result, i);
1929 gst_caps_remove_structure (caps, i);
1941 /* gst_caps_do_simplify (caps); */
1947 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
1949 * gst_caps_save_thyself:
1950 * @caps: a #GstCaps structure
1951 * @parent: a XML parent node
1953 * Serializes a #GstCaps to XML and adds it as a child node of @parent.
1955 * Returns: a XML node pointer
1958 gst_caps_save_thyself (const GstCaps * caps, xmlNodePtr parent)
1960 char *s = gst_caps_to_string (caps);
1962 xmlNewChild (parent, NULL, (xmlChar *) "caps", (xmlChar *) s);
1968 * gst_caps_load_thyself:
1969 * @parent: a XML node
1971 * Creates a #GstCaps from its XML serialization.
1973 * Returns: a new #GstCaps structure
1976 gst_caps_load_thyself (xmlNodePtr parent)
1978 if (strcmp ("caps", (char *) parent->name) == 0) {
1979 return gst_caps_from_string ((gchar *) xmlNodeGetContent (parent));
1990 * @caps: (inout) (transfer full): a pointer to #GstCaps
1991 * @newcaps: a #GstCaps to replace *caps
1993 * Replaces *caps with @newcaps. Unrefs the #GstCaps in the location
1994 * pointed to by @caps, if applicable, then modifies @caps to point to
1995 * @newcaps. An additional ref on @newcaps is taken.
1997 * This function does not take any locks so you might want to lock
1998 * the object owning @caps pointer.
2001 gst_caps_replace (GstCaps ** caps, GstCaps * newcaps)
2005 g_return_if_fail (caps != NULL);
2009 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p, %p -> %p", caps, oldcaps, newcaps);
2011 if (newcaps != oldcaps) {
2013 gst_caps_ref (newcaps);
2018 gst_caps_unref (oldcaps);
2023 * gst_caps_to_string:
2026 * Converts @caps to a string representation. This string representation
2027 * can be converted back to a #GstCaps by gst_caps_from_string().
2029 * For debugging purposes its easier to do something like this:
2031 * GST_LOG ("caps are %" GST_PTR_FORMAT, caps);
2033 * This prints the caps in human readble form.
2035 * Returns: (transfer full): a newly allocated string representing @caps.
2038 gst_caps_to_string (const GstCaps * caps)
2040 guint i, slen, clen;
2043 /* NOTE: This function is potentially called by the debug system,
2044 * so any calls to gst_log() (and GST_DEBUG(), GST_LOG(), etc.)
2045 * should be careful to avoid recursion. This includes any functions
2046 * called by gst_caps_to_string. In particular, calls should
2047 * not use the GST_PTR_FORMAT extension. */
2050 return g_strdup ("NULL");
2052 if (CAPS_IS_ANY (caps)) {
2053 return g_strdup ("ANY");
2055 if (CAPS_IS_EMPTY_SIMPLE (caps)) {
2056 return g_strdup ("EMPTY");
2059 /* estimate a rough string length to avoid unnecessary reallocs in GString */
2061 clen = caps->structs->len;
2062 for (i = 0; i < clen; i++) {
2064 STRUCTURE_ESTIMATED_STRING_LEN (gst_caps_get_structure_unchecked (caps,
2068 s = g_string_sized_new (slen);
2069 for (i = 0; i < clen; i++) {
2070 GstStructure *structure;
2073 /* ';' is now added by gst_structure_to_string */
2074 g_string_append_c (s, ' ');
2077 structure = gst_caps_get_structure_unchecked (caps, i);
2078 priv_gst_structure_append_to_gstring (structure, s);
2080 if (s->len && s->str[s->len - 1] == ';') {
2081 /* remove latest ';' */
2082 s->str[--s->len] = '\0';
2084 return g_string_free (s, FALSE);
2088 gst_caps_from_string_inplace (GstCaps * caps, const gchar * string)
2090 GstStructure *structure;
2093 if (strcmp ("ANY", string) == 0) {
2094 caps->flags = GST_CAPS_FLAGS_ANY;
2097 if (strcmp ("EMPTY", string) == 0) {
2101 structure = gst_structure_from_string (string, &s);
2102 if (structure == NULL) {
2105 gst_caps_append_structure_unchecked (caps, structure);
2109 while (g_ascii_isspace (*s))
2114 structure = gst_structure_from_string (s, &s);
2115 if (structure == NULL) {
2118 gst_caps_append_structure_unchecked (caps, structure);
2126 * gst_caps_from_string:
2127 * @string: a string to convert to #GstCaps
2129 * Converts @caps from a string representation.
2131 * Returns: (transfer full): a newly allocated #GstCaps
2134 gst_caps_from_string (const gchar * string)
2138 g_return_val_if_fail (string, FALSE);
2140 caps = gst_caps_new_empty ();
2141 if (gst_caps_from_string_inplace (caps, string)) {
2144 gst_caps_unref (caps);
2150 gst_caps_transform_to_string (const GValue * src_value, GValue * dest_value)
2152 g_return_if_fail (G_IS_VALUE (src_value));
2153 g_return_if_fail (G_IS_VALUE (dest_value));
2154 g_return_if_fail (G_VALUE_HOLDS (src_value, GST_TYPE_CAPS));
2155 g_return_if_fail (G_VALUE_HOLDS (dest_value, G_TYPE_STRING)
2156 || G_VALUE_HOLDS (dest_value, G_TYPE_POINTER));
2158 g_value_take_string (dest_value,
2159 gst_caps_to_string (gst_value_get_caps (src_value)));
2163 gst_caps_copy_conditional (GstCaps * src)
2166 return gst_caps_ref (src);