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 #define DEBUG_REFCOUNT
78 #define CAPS_POISON(caps) G_STMT_START{ \
80 GstCaps *_newcaps = _gst_caps_copy (caps); \
81 gst_caps_unref(caps); \
85 #define STRUCTURE_POISON(structure) G_STMT_START{ \
87 GstStructure *_newstruct = gst_structure_copy (structure); \
88 gst_structure_free(structure); \
89 structure = _newstruct; \
92 #define IS_WRITABLE(caps) \
93 (GST_CAPS_REFCOUNT_VALUE (caps) == 1)
95 /* same as gst_caps_is_any () */
96 #define CAPS_IS_ANY(caps) \
97 (GST_CAPS_FLAGS(caps) & GST_CAPS_FLAGS_ANY)
99 /* same as gst_caps_is_empty () */
100 #define CAPS_IS_EMPTY(caps) \
101 (!CAPS_IS_ANY(caps) && CAPS_IS_EMPTY_SIMPLE(caps))
103 #define CAPS_IS_EMPTY_SIMPLE(caps) \
104 (((caps)->structs == NULL) || ((caps)->structs->len == 0))
106 /* quick way to get a caps structure at an index without doing a type or array
108 #define gst_caps_get_structure_unchecked(caps, index) \
109 ((GstStructure *)g_ptr_array_index ((caps)->structs, (index)))
110 /* quick way to append a structure without checking the args */
111 #define gst_caps_append_structure_unchecked(caps, structure) G_STMT_START{\
112 GstStructure *__s=structure; \
113 gst_structure_set_parent_refcount (__s, &GST_MINI_OBJECT_REFCOUNT(caps)); \
114 g_ptr_array_add (caps->structs, __s); \
117 /* lock to protect multiple invocations of static caps to caps conversion */
118 G_LOCK_DEFINE_STATIC (static_caps_lock);
120 static void gst_caps_transform_to_string (const GValue * src_value,
121 GValue * dest_value);
122 static gboolean gst_caps_from_string_inplace (GstCaps * caps,
123 const gchar * string);
125 static GType _gst_caps_type = 0;
128 gst_caps_get_type (void)
130 if (G_UNLIKELY (_gst_caps_type == 0)) {
131 _gst_caps_type = gst_mini_object_register ("GstCaps");
133 g_value_register_transform_func (_gst_caps_type,
134 G_TYPE_STRING, gst_caps_transform_to_string);
137 return _gst_caps_type;
141 _gst_caps_copy (const GstCaps * caps)
144 GstStructure *structure;
147 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
149 newcaps = gst_caps_new_empty ();
150 GST_CAPS_FLAGS (newcaps) = GST_CAPS_FLAGS (caps);
151 n = caps->structs->len;
153 for (i = 0; i < n; i++) {
154 structure = gst_caps_get_structure_unchecked (caps, i);
155 gst_caps_append_structure (newcaps, gst_structure_copy (structure));
161 /* creation/deletion */
163 _gst_caps_free (GstCaps * caps)
165 GstStructure *structure;
168 /* The refcount must be 0, but since we're only called by gst_caps_unref,
169 * don't bother testing. */
170 len = caps->structs->len;
171 /* This can be used to get statistics about caps sizes */
172 /*GST_CAT_INFO (GST_CAT_CAPS, "caps size: %d", len); */
173 for (i = 0; i < len; i++) {
174 structure = (GstStructure *) gst_caps_get_structure_unchecked (caps, i);
175 gst_structure_set_parent_refcount (structure, NULL);
176 gst_structure_free (structure);
178 g_ptr_array_free (caps->structs, TRUE);
180 memset (caps, 0xff, sizeof (GstCaps));
183 #ifdef DEBUG_REFCOUNT
184 GST_CAT_LOG (GST_CAT_CAPS, "freeing caps %p", caps);
186 g_slice_free (GstCaps, caps);
190 gst_caps_init (GstCaps * caps)
192 gst_mini_object_init (GST_MINI_OBJECT_CAST (caps),
193 _gst_caps_type, sizeof (GstCaps));
195 caps->mini_object.copy = (GstMiniObjectCopyFunction) _gst_caps_copy;
196 caps->mini_object.dispose = NULL;
197 caps->mini_object.free = (GstMiniObjectFreeFunction) _gst_caps_free;
199 /* the 32 has been determined by logging caps sizes in _gst_caps_free
200 * but g_ptr_array uses 16 anyway if it expands once, so this does not help
202 * caps->structs = g_ptr_array_sized_new (32);
204 caps->structs = g_ptr_array_new ();
208 * gst_caps_new_empty:
210 * Creates a new #GstCaps that is empty. That is, the returned
211 * #GstCaps contains no media formats.
212 * Caller is responsible for unreffing the returned caps.
214 * Returns: (transfer full): the new #GstCaps
217 gst_caps_new_empty (void)
221 caps = g_slice_new (GstCaps);
223 gst_caps_init (caps);
225 #ifdef DEBUG_REFCOUNT
226 GST_CAT_LOG (GST_CAT_CAPS, "created caps %p", caps);
235 * Creates a new #GstCaps that indicates that it is compatible with
238 * Returns: (transfer full): the new #GstCaps
241 gst_caps_new_any (void)
243 GstCaps *caps = gst_caps_new_empty ();
245 GST_CAPS_FLAG_SET (caps, GST_CAPS_FLAGS_ANY);
251 * gst_caps_new_simple:
252 * @media_type: the media type of the structure
253 * @fieldname: first field to set
254 * @...: additional arguments
256 * Creates a new #GstCaps that contains one #GstStructure. The
257 * structure is defined by the arguments, which have the same format
258 * as gst_structure_new().
259 * Caller is responsible for unreffing the returned caps.
261 * Returns: (transfer full): the new #GstCaps
264 gst_caps_new_simple (const char *media_type, const char *fieldname, ...)
267 GstStructure *structure;
270 caps = gst_caps_new_empty ();
272 va_start (var_args, fieldname);
273 structure = gst_structure_new_valist (media_type, fieldname, var_args);
276 gst_caps_append_structure_unchecked (caps, structure);
283 * @struct1: the first structure to add
284 * @...: additional structures to add
286 * Creates a new #GstCaps and adds all the structures listed as
287 * arguments. The list must be NULL-terminated. The structures
288 * are not copied; the returned #GstCaps owns the structures.
290 * Returns: (transfer full): the new #GstCaps
293 gst_caps_new_full (GstStructure * struct1, ...)
298 va_start (var_args, struct1);
299 caps = gst_caps_new_full_valist (struct1, var_args);
306 * gst_caps_new_full_valist:
307 * @structure: the first structure to add
308 * @var_args: additional structures to add
310 * Creates a new #GstCaps and adds all the structures listed as
311 * arguments. The list must be NULL-terminated. The structures
312 * are not copied; the returned #GstCaps owns the structures.
314 * Returns: (transfer full): the new #GstCaps
317 gst_caps_new_full_valist (GstStructure * structure, va_list var_args)
321 caps = gst_caps_new_empty ();
324 gst_caps_append_structure_unchecked (caps, structure);
325 structure = va_arg (var_args, GstStructure *);
332 * gst_caps_make_writable:
333 * @caps: (transfer full): the #GstCaps to make writable
335 * Returns a writable copy of @caps.
337 * If there is only one reference count on @caps, the caller must be the owner,
338 * and so this function will return the caps object unchanged. If on the other
339 * hand there is more than one reference on the object, a new caps object will
340 * be returned. The caller's reference on @caps will be removed, and instead the
341 * caller will own a reference to the returned object.
343 * In short, this function unrefs the caps in the argument and refs the caps
344 * that it returns. Don't access the argument after calling this function. See
345 * also: gst_caps_ref().
347 * Returns: (transfer full): the same #GstCaps object.
350 gst_caps_make_writable (GstCaps * caps)
354 g_return_val_if_fail (caps != NULL, NULL);
356 /* we are the only instance reffing this caps */
357 if (IS_WRITABLE (caps))
361 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy caps");
362 copy = _gst_caps_copy (caps);
363 gst_caps_unref (caps);
369 gst_static_caps_get_type (void)
371 static GType staticcaps_type = 0;
373 if (G_UNLIKELY (staticcaps_type == 0)) {
374 staticcaps_type = g_pointer_type_register_static ("GstStaticCaps");
376 return staticcaps_type;
381 * gst_static_caps_get:
382 * @static_caps: the #GstStaticCaps to convert
384 * Converts a #GstStaticCaps to a #GstCaps.
386 * Returns: (transfer full): a pointer to the #GstCaps. Unref after usage.
387 * Since the core holds an additional ref to the returned caps,
388 * use gst_caps_make_writable() on the returned caps to modify it.
391 gst_static_caps_get (GstStaticCaps * static_caps)
395 g_return_val_if_fail (static_caps != NULL, NULL);
397 caps = (GstCaps *) static_caps;
399 /* refcount is 0 when we need to convert */
400 if (G_UNLIKELY (GST_CAPS_REFCOUNT_VALUE (caps) == 0)) {
404 G_LOCK (static_caps_lock);
405 /* check if other thread already updated */
406 if (G_UNLIKELY (GST_CAPS_REFCOUNT_VALUE (caps) > 0))
409 string = static_caps->string;
411 if (G_UNLIKELY (string == NULL))
414 GST_CAT_LOG (GST_CAT_CAPS, "creating %p", static_caps);
416 /* we construct the caps on the stack, then copy over the struct into our
417 * real caps, refcount last. We do this because we must leave the refcount
418 * of the result caps to 0 so that other threads don't run away with the
419 * caps while we are constructing it. */
420 gst_caps_init (&temp);
422 /* convert to string */
423 if (G_UNLIKELY (!gst_caps_from_string_inplace (&temp, string)))
424 g_critical ("Could not convert static caps \"%s\"", string);
426 gst_caps_init (caps);
427 /* now copy stuff over to the real caps. */
428 GST_CAPS_FLAGS (caps) = GST_CAPS_FLAGS (&temp);
429 caps->structs = temp.structs;
431 GST_CAT_LOG (GST_CAT_CAPS, "created %p", static_caps);
433 G_UNLOCK (static_caps_lock);
435 /* ref the caps, makes it not writable */
443 G_UNLOCK (static_caps_lock);
444 g_warning ("static caps %p string is NULL", static_caps);
451 static GstStructure *
452 gst_caps_remove_and_get_structure (GstCaps * caps, guint idx)
454 /* don't use index_fast, gst_caps_do_simplify relies on the order */
455 GstStructure *s = g_ptr_array_remove_index (caps->structs, idx);
457 gst_structure_set_parent_refcount (s, NULL);
462 * gst_caps_steal_structure:
463 * @caps: the #GstCaps to retrieve from
464 * @index: Index of the structure to retrieve
466 * Retrieves the stucture with the given index from the list of structures
467 * contained in @caps. The caller becomes the owner of the returned structure.
469 * Returns: (transfer full): a pointer to the #GstStructure corresponding
475 gst_caps_steal_structure (GstCaps * caps, guint index)
477 g_return_val_if_fail (caps != NULL, NULL);
478 g_return_val_if_fail (IS_WRITABLE (caps), NULL);
480 if (G_UNLIKELY (index >= caps->structs->len))
483 return gst_caps_remove_and_get_structure (caps, index);
487 gst_structure_is_equal_foreach (GQuark field_id, const GValue * val2,
490 GstStructure *struct1 = (GstStructure *) data;
491 const GValue *val1 = gst_structure_id_get_value (struct1, field_id);
493 if (G_UNLIKELY (val1 == NULL))
495 if (gst_value_compare (val1, val2) == GST_VALUE_EQUAL) {
503 gst_caps_structure_is_subset_field (GQuark field_id, const GValue * value,
506 GstStructure *subtract_from = user_data;
507 GValue subtraction = { 0, };
510 if (!(other = gst_structure_id_get_value (subtract_from, field_id)))
511 /* field is missing in one set */
514 /* equal values are subset */
515 if (gst_value_compare (other, value) == GST_VALUE_EQUAL)
523 * -> 1 - [1,2] = empty
527 * -> [1,2] - [1,3] = empty
531 * -> {1,3} - {1,2} = 3
534 * First caps subtraction needs to return a non-empty set, second
535 * subtractions needs to give en empty set.
537 if (gst_value_subtract (&subtraction, other, value)) {
538 g_value_unset (&subtraction);
539 /* !empty result, swapping must be empty */
540 if (!gst_value_subtract (&subtraction, value, other))
543 g_value_unset (&subtraction);
549 gst_caps_structure_is_subset (const GstStructure * minuend,
550 const GstStructure * subtrahend)
552 if ((minuend->name != subtrahend->name) ||
553 (gst_structure_n_fields (minuend) !=
554 gst_structure_n_fields (subtrahend))) {
558 return gst_structure_foreach ((GstStructure *) subtrahend,
559 gst_caps_structure_is_subset_field, (gpointer) minuend);
564 * @caps1: the #GstCaps that will be appended to
565 * @caps2: (transfer full): the #GstCaps to append
567 * Appends the structures contained in @caps2 to @caps1. The structures in
568 * @caps2 are not copied -- they are transferred to @caps1, and then @caps2 is
569 * freed. If either caps is ANY, the resulting caps will be ANY.
572 gst_caps_append (GstCaps * caps1, GstCaps * caps2)
574 GstStructure *structure;
577 g_return_if_fail (GST_IS_CAPS (caps1));
578 g_return_if_fail (GST_IS_CAPS (caps2));
579 g_return_if_fail (IS_WRITABLE (caps1));
580 g_return_if_fail (IS_WRITABLE (caps2));
585 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))) {
586 /* FIXME: this leaks */
587 GST_CAPS_FLAGS (caps1) |= GST_CAPS_FLAGS_ANY;
588 for (i = caps2->structs->len - 1; i >= 0; i--) {
589 structure = gst_caps_remove_and_get_structure (caps2, i);
590 gst_structure_free (structure);
593 for (i = caps2->structs->len; i; i--) {
594 structure = gst_caps_remove_and_get_structure (caps2, 0);
595 gst_caps_append_structure_unchecked (caps1, structure);
598 gst_caps_unref (caps2); /* guaranteed to free it */
603 * @caps1: the #GstCaps that will take the new entries
604 * @caps2: (transfer full): the #GstCaps to merge in
606 * Appends the structures contained in @caps2 to @caps1 if they are not yet
607 * expressed by @caps1. The structures in @caps2 are not copied -- they are
608 * transferred to @caps1, and then @caps2 is freed.
609 * If either caps is ANY, the resulting caps will be ANY.
614 gst_caps_merge (GstCaps * caps1, GstCaps * caps2)
616 GstStructure *structure;
619 g_return_if_fail (GST_IS_CAPS (caps1));
620 g_return_if_fail (GST_IS_CAPS (caps2));
621 g_return_if_fail (IS_WRITABLE (caps1));
622 g_return_if_fail (IS_WRITABLE (caps2));
627 if (G_UNLIKELY (CAPS_IS_ANY (caps1))) {
628 for (i = caps2->structs->len - 1; i >= 0; i--) {
629 structure = gst_caps_remove_and_get_structure (caps2, i);
630 gst_structure_free (structure);
632 } else if (G_UNLIKELY (CAPS_IS_ANY (caps2))) {
633 GST_CAPS_FLAGS (caps1) |= GST_CAPS_FLAGS_ANY;
634 for (i = caps1->structs->len - 1; i >= 0; i--) {
635 structure = gst_caps_remove_and_get_structure (caps1, i);
636 gst_structure_free (structure);
639 for (i = caps2->structs->len; i; i--) {
640 structure = gst_caps_remove_and_get_structure (caps2, 0);
641 gst_caps_merge_structure (caps1, structure);
644 GstCaps *com = gst_caps_intersect (caps1, caps2);
645 GstCaps *add = gst_caps_subtract (caps2, com);
647 GST_DEBUG ("common : %d", gst_caps_get_size (com));
648 GST_DEBUG ("adding : %d", gst_caps_get_size (add));
649 gst_caps_append (caps1, add);
650 gst_caps_unref (com);
653 gst_caps_unref (caps2); /* guaranteed to free it */
657 * gst_caps_append_structure:
658 * @caps: the #GstCaps that will be appended to
659 * @structure: (transfer full): the #GstStructure to append
661 * Appends @structure to @caps. The structure is not copied; @caps
662 * becomes the owner of @structure.
665 gst_caps_append_structure (GstCaps * caps, GstStructure * structure)
667 g_return_if_fail (GST_IS_CAPS (caps));
668 g_return_if_fail (IS_WRITABLE (caps));
670 if (G_LIKELY (structure)) {
671 g_return_if_fail (structure->parent_refcount == NULL);
674 STRUCTURE_POISON (structure);
677 gst_caps_append_structure_unchecked (caps, structure);
682 * gst_caps_remove_structure:
683 * @caps: the #GstCaps to remove from
684 * @idx: Index of the structure to remove
686 * removes the stucture with the given index from the list of structures
687 * contained in @caps.
690 gst_caps_remove_structure (GstCaps * caps, guint idx)
692 GstStructure *structure;
694 g_return_if_fail (caps != NULL);
695 g_return_if_fail (idx <= gst_caps_get_size (caps));
696 g_return_if_fail (IS_WRITABLE (caps));
698 structure = gst_caps_remove_and_get_structure (caps, idx);
699 gst_structure_free (structure);
703 * gst_caps_merge_structure:
704 * @caps: the #GstCaps that will the the new structure
705 * @structure: (transfer full): the #GstStructure to merge
707 * Appends @structure to @caps if its not already expressed by @caps. The
708 * structure is not copied; @caps becomes the owner of @structure.
711 gst_caps_merge_structure (GstCaps * caps, GstStructure * structure)
713 g_return_if_fail (GST_IS_CAPS (caps));
714 g_return_if_fail (IS_WRITABLE (caps));
716 if (G_LIKELY (structure)) {
717 GstStructure *structure1;
719 gboolean unique = TRUE;
721 g_return_if_fail (structure->parent_refcount == NULL);
724 STRUCTURE_POISON (structure);
727 /* check each structure */
728 for (i = caps->structs->len - 1; i >= 0; i--) {
729 structure1 = gst_caps_get_structure_unchecked (caps, i);
730 /* if structure is a subset of structure1, then skip it */
731 if (gst_caps_structure_is_subset (structure1, structure)) {
737 gst_caps_append_structure_unchecked (caps, structure);
739 gst_structure_free (structure);
748 * Gets the number of structures contained in @caps.
750 * Returns: the number of structures that @caps contains
753 gst_caps_get_size (const GstCaps * caps)
755 g_return_val_if_fail (GST_IS_CAPS (caps), 0);
757 return caps->structs->len;
761 * gst_caps_get_structure:
763 * @index: the index of the structure
765 * Finds the structure in @caps that has the index @index, and
768 * WARNING: This function takes a const GstCaps *, but returns a
769 * non-const GstStructure *. This is for programming convenience --
770 * the caller should be aware that structures inside a constant
771 * #GstCaps should not be modified. However, if you know the caps
772 * are writable, either because you have just copied them or made
773 * them writable with gst_caps_make_writable(), you may modify the
774 * structure returned in the usual way, e.g. with functions like
775 * gst_structure_set().
777 * You do not need to free or unref the structure returned, it
778 * belongs to the #GstCaps.
780 * Returns: (transfer none): a pointer to the #GstStructure corresponding
784 gst_caps_get_structure (const GstCaps * caps, guint index)
786 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
787 g_return_val_if_fail (index < caps->structs->len, NULL);
789 return gst_caps_get_structure_unchecked (caps, index);
794 * @caps: the #GstCaps to copy
795 * @nth: the nth structure to copy
797 * Creates a new #GstCaps and appends a copy of the nth structure
798 * contained in @caps.
800 * Returns: (transfer full): the new #GstCaps
803 gst_caps_copy_nth (const GstCaps * caps, guint nth)
806 GstStructure *structure;
808 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
810 newcaps = gst_caps_new_empty ();
811 GST_CAPS_FLAGS (newcaps) = GST_CAPS_FLAGS (caps);
813 if (G_LIKELY (caps->structs->len > nth)) {
814 structure = gst_caps_get_structure_unchecked (caps, nth);
815 gst_caps_append_structure_unchecked (newcaps,
816 gst_structure_copy (structure));
824 * @caps: the #GstCaps to truncate
826 * Destructively discard all but the first structure from @caps. Useful when
827 * fixating. @caps must be writable.
830 gst_caps_truncate (GstCaps * caps)
834 g_return_if_fail (GST_IS_CAPS (caps));
835 g_return_if_fail (IS_WRITABLE (caps));
837 i = caps->structs->len - 1;
840 gst_caps_remove_structure (caps, i--);
844 * gst_caps_set_value:
845 * @caps: a writable caps
846 * @field: name of the field to set
847 * @value: value to set the field to
849 * Sets the given @field on all structures of @caps to the given @value.
850 * This is a convenience function for calling gst_structure_set_value() on
851 * all structures of @caps.
856 gst_caps_set_value (GstCaps * caps, const char *field, const GValue * value)
860 g_return_if_fail (GST_IS_CAPS (caps));
861 g_return_if_fail (IS_WRITABLE (caps));
862 g_return_if_fail (field != NULL);
863 g_return_if_fail (G_IS_VALUE (value));
865 len = caps->structs->len;
866 for (i = 0; i < len; i++) {
867 GstStructure *structure = gst_caps_get_structure_unchecked (caps, i);
868 gst_structure_set_value (structure, field, value);
873 * gst_caps_set_simple_valist:
874 * @caps: the #GstCaps to set
875 * @field: first field to set
876 * @varargs: additional parameters
878 * Sets fields in a #GstCaps. The arguments must be passed in the same
879 * manner as gst_structure_set(), and be NULL-terminated.
880 * <note>Prior to GStreamer version 0.10.26, this function failed when
881 * @caps was not simple. If your code needs to work with those versions
882 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
883 * is %TRUE for @caps.</note>
886 gst_caps_set_simple_valist (GstCaps * caps, const char *field, va_list varargs)
888 GValue value = { 0, };
890 g_return_if_fail (GST_IS_CAPS (caps));
891 g_return_if_fail (IS_WRITABLE (caps));
897 type = va_arg (varargs, GType);
899 if (G_UNLIKELY (type == G_TYPE_DATE)) {
900 g_warning ("Don't use G_TYPE_DATE, use GST_TYPE_DATE instead\n");
901 type = GST_TYPE_DATE;
903 #if GLIB_CHECK_VERSION(2,23,3)
904 G_VALUE_COLLECT_INIT (&value, type, varargs, 0, &err);
906 g_value_init (&value, type);
907 G_VALUE_COLLECT (&value, varargs, 0, &err);
909 if (G_UNLIKELY (err)) {
910 g_critical ("%s", err);
914 gst_caps_set_value (caps, field, &value);
916 g_value_unset (&value);
918 field = va_arg (varargs, const gchar *);
923 * gst_caps_set_simple:
924 * @caps: the #GstCaps to set
925 * @field: first field to set
926 * @...: additional parameters
928 * Sets fields in a #GstCaps. The arguments must be passed in the same
929 * manner as gst_structure_set(), and be NULL-terminated.
930 * <note>Prior to GStreamer version 0.10.26, this function failed when
931 * @caps was not simple. If your code needs to work with those versions
932 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
933 * is %TRUE for @caps.</note>
936 gst_caps_set_simple (GstCaps * caps, const char *field, ...)
940 g_return_if_fail (GST_IS_CAPS (caps));
941 g_return_if_fail (IS_WRITABLE (caps));
943 va_start (var_args, field);
944 gst_caps_set_simple_valist (caps, field, var_args);
952 * @caps: the #GstCaps to test
954 * Determines if @caps represents any media format.
956 * Returns: TRUE if @caps represents any format.
959 gst_caps_is_any (const GstCaps * caps)
961 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
963 return (CAPS_IS_ANY (caps));
968 * @caps: the #GstCaps to test
970 * Determines if @caps represents no media formats.
972 * Returns: TRUE if @caps represents no formats.
975 gst_caps_is_empty (const GstCaps * caps)
977 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
979 if (CAPS_IS_ANY (caps))
982 return CAPS_IS_EMPTY_SIMPLE (caps);
986 gst_caps_is_fixed_foreach (GQuark field_id, const GValue * value,
989 return gst_value_is_fixed (value);
994 * @caps: the #GstCaps to test
996 * Fixed #GstCaps describe exactly one format, that is, they have exactly
997 * one structure, and each field in the structure describes a fixed type.
998 * Examples of non-fixed types are GST_TYPE_INT_RANGE and GST_TYPE_LIST.
1000 * Returns: TRUE if @caps is fixed
1003 gst_caps_is_fixed (const GstCaps * caps)
1005 GstStructure *structure;
1007 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1009 if (caps->structs->len != 1)
1012 structure = gst_caps_get_structure_unchecked (caps, 0);
1014 return gst_structure_foreach (structure, gst_caps_is_fixed_foreach, NULL);
1018 * gst_caps_is_equal_fixed:
1019 * @caps1: the #GstCaps to test
1020 * @caps2: the #GstCaps to test
1022 * Tests if two #GstCaps are equal. This function only works on fixed
1025 * Returns: TRUE if the arguments represent the same format
1028 gst_caps_is_equal_fixed (const GstCaps * caps1, const GstCaps * caps2)
1030 GstStructure *struct1, *struct2;
1032 g_return_val_if_fail (gst_caps_is_fixed (caps1), FALSE);
1033 g_return_val_if_fail (gst_caps_is_fixed (caps2), FALSE);
1035 struct1 = gst_caps_get_structure_unchecked (caps1, 0);
1036 struct2 = gst_caps_get_structure_unchecked (caps2, 0);
1038 if (struct1->name != struct2->name) {
1041 if (struct1->fields->len != struct2->fields->len) {
1045 return gst_structure_foreach (struct1, gst_structure_is_equal_foreach,
1050 * gst_caps_is_always_compatible:
1051 * @caps1: the #GstCaps to test
1052 * @caps2: the #GstCaps to test
1054 * A given #GstCaps structure is always compatible with another if
1055 * every media format that is in the first is also contained in the
1056 * second. That is, @caps1 is a subset of @caps2.
1058 * Returns: TRUE if @caps1 is a subset of @caps2.
1061 gst_caps_is_always_compatible (const GstCaps * caps1, const GstCaps * caps2)
1063 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1064 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1066 return gst_caps_is_subset (caps1, caps2);
1070 * gst_caps_is_subset:
1071 * @subset: a #GstCaps
1072 * @superset: a potentially greater #GstCaps
1074 * Checks if all caps represented by @subset are also represented by @superset.
1075 * <note>This function does not work reliably if optional properties for caps
1076 * are included on one caps and omitted on the other.</note>
1078 * Returns: %TRUE if @subset is a subset of @superset
1081 gst_caps_is_subset (const GstCaps * subset, const GstCaps * superset)
1086 g_return_val_if_fail (subset != NULL, FALSE);
1087 g_return_val_if_fail (superset != NULL, FALSE);
1089 if (CAPS_IS_EMPTY (subset) || CAPS_IS_ANY (superset))
1091 if (CAPS_IS_ANY (subset) || CAPS_IS_EMPTY (superset))
1094 caps = gst_caps_subtract (subset, superset);
1095 ret = CAPS_IS_EMPTY_SIMPLE (caps);
1096 gst_caps_unref (caps);
1101 * gst_caps_is_equal:
1102 * @caps1: a #GstCaps
1103 * @caps2: another #GstCaps
1105 * Checks if the given caps represent the same set of caps.
1106 * <note>This function does not work reliably if optional properties for caps
1107 * are included on one caps and omitted on the other.</note>
1109 * This function deals correctly with passing NULL for any of the caps.
1111 * Returns: TRUE if both caps are equal.
1114 gst_caps_is_equal (const GstCaps * caps1, const GstCaps * caps2)
1116 /* FIXME 0.11: NULL pointers are no valid Caps but indicate an error
1117 * So there should be an assertion that caps1 and caps2 != NULL */
1119 /* NULL <-> NULL is allowed here */
1120 if (G_UNLIKELY (caps1 == caps2))
1123 /* one of them NULL => they are different (can't be both NULL because
1124 * we checked that above) */
1125 if (G_UNLIKELY (caps1 == NULL || caps2 == NULL))
1128 if (G_UNLIKELY (gst_caps_is_fixed (caps1) && gst_caps_is_fixed (caps2)))
1129 return gst_caps_is_equal_fixed (caps1, caps2);
1131 return gst_caps_is_subset (caps1, caps2) && gst_caps_is_subset (caps2, caps1);
1134 /* intersect operation */
1139 const GstStructure *intersect;
1144 gst_caps_structure_intersect_field1 (GQuark id, const GValue * val1,
1147 IntersectData *idata = (IntersectData *) data;
1148 const GValue *val2 = gst_structure_id_get_value (idata->intersect, id);
1150 if (G_UNLIKELY (val2 == NULL)) {
1151 gst_structure_id_set_value (idata->dest, id, val1);
1153 GValue dest_value = { 0 };
1154 if (gst_value_intersect (&dest_value, val1, val2)) {
1155 gst_structure_id_set_value (idata->dest, id, &dest_value);
1156 g_value_unset (&dest_value);
1165 gst_caps_structure_intersect_field2 (GQuark id, const GValue * val1,
1168 IntersectData *idata = (IntersectData *) data;
1169 const GValue *val2 = gst_structure_id_get_value (idata->intersect, id);
1171 if (G_UNLIKELY (val2 == NULL)) {
1172 gst_structure_id_set_value (idata->dest, id, val1);
1177 static GstStructure *
1178 gst_caps_structure_intersect (const GstStructure * struct1,
1179 const GstStructure * struct2)
1183 g_assert (struct1 != NULL);
1184 g_assert (struct2 != NULL);
1186 if (G_UNLIKELY (struct1->name != struct2->name))
1189 /* copy fields from struct1 which we have not in struct2 to target
1190 * intersect if we have the field in both */
1191 data.dest = gst_structure_id_empty_new (struct1->name);
1192 data.intersect = struct2;
1193 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct1,
1194 gst_caps_structure_intersect_field1, &data)))
1197 /* copy fields from struct2 which we have not in struct1 to target */
1198 data.intersect = struct1;
1199 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct2,
1200 gst_caps_structure_intersect_field2, &data)))
1206 gst_structure_free (data.dest);
1211 gst_caps_structure_can_intersect_field (GQuark id, const GValue * val1,
1214 GstStructure *other = (GstStructure *) data;
1215 const GValue *val2 = gst_structure_id_get_value (other, id);
1217 if (G_LIKELY (val2)) {
1218 if (!gst_value_can_intersect (val1, val2)) {
1221 gint eq = gst_value_compare (val1, val2);
1223 if (eq == GST_VALUE_UNORDERED) {
1224 /* we need to try interseting */
1225 GValue dest_value = { 0 };
1226 if (gst_value_intersect (&dest_value, val1, val2)) {
1227 g_value_unset (&dest_value);
1231 } else if (eq != GST_VALUE_EQUAL) {
1240 gst_caps_structure_can_intersect (const GstStructure * struct1,
1241 const GstStructure * struct2)
1243 g_assert (struct1 != NULL);
1244 g_assert (struct2 != NULL);
1246 if (G_UNLIKELY (struct1->name != struct2->name))
1249 /* tries to intersect if we have the field in both */
1250 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct1,
1251 gst_caps_structure_can_intersect_field, (gpointer) struct2)))
1258 * gst_caps_can_intersect:
1259 * @caps1: a #GstCaps to intersect
1260 * @caps2: a #GstCaps to intersect
1262 * Tries intersecting @caps1 and @caps2 and reports whether the result would not
1265 * Returns: %TRUE if intersection would be not empty
1270 gst_caps_can_intersect (const GstCaps * caps1, const GstCaps * caps2)
1272 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1273 guint j, k, len1, len2;
1274 GstStructure *struct1;
1275 GstStructure *struct2;
1277 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1278 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1280 /* caps are exactly the same pointers */
1281 if (G_UNLIKELY (caps1 == caps2))
1284 /* empty caps on either side, return empty */
1285 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1288 /* one of the caps is any */
1289 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2)))
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:
1299 * +------------- total distance: +-------------
1300 * | 1 2 4 7 0 | 0 1 2 3
1301 * caps2 | 3 5 8 10 1 | 1 2 3 4
1302 * | 6 9 11 12 2 | 2 3 4 5
1304 * First we iterate over the caps1 structures (top line) intersecting
1305 * the structures diagonally down, then we iterate over the caps2
1306 * structures. The result is that the intersections are ordered based on the
1307 * sum of the indexes in the list.
1309 len1 = caps1->structs->len;
1310 len2 = caps2->structs->len;
1311 for (i = 0; i < len1 + len2 - 1; i++) {
1312 /* superset index goes from 0 to sgst_caps_structure_intersectuperset->structs->len-1 */
1313 j = MIN (i, len1 - 1);
1314 /* subset index stays 0 until i reaches superset->structs->len, then it
1315 * counts up from 1 to subset->structs->len - 1 */
1318 /* now run the diagonal line, end condition is the left or bottom
1321 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1322 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1324 if (gst_caps_structure_can_intersect (struct1, struct2)) {
1327 /* move down left */
1329 if (G_UNLIKELY (j == 0))
1330 break; /* so we don't roll back to G_MAXUINT */
1338 * gst_caps_intersect:
1339 * @caps1: a #GstCaps to intersect
1340 * @caps2: a #GstCaps to intersect
1342 * Creates a new #GstCaps that contains all the formats that are common
1343 * to both @caps1 and @caps2.
1345 * Returns: the new #GstCaps
1348 gst_caps_intersect (const GstCaps * caps1, const GstCaps * caps2)
1350 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1351 guint j, k, len1, len2;
1353 GstStructure *struct1;
1354 GstStructure *struct2;
1356 GstStructure *istruct;
1358 g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
1359 g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
1361 /* caps are exactly the same pointers, just copy one caps */
1362 if (G_UNLIKELY (caps1 == caps2))
1363 return _gst_caps_copy (caps1);
1365 /* empty caps on either side, return empty */
1366 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1367 return gst_caps_new_empty ();
1369 /* one of the caps is any, just copy the other caps */
1370 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1371 return _gst_caps_copy (caps2);
1372 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1373 return _gst_caps_copy (caps1);
1375 dest = gst_caps_new_empty ();
1377 /* run zigzag on top line then right line, this preserves the caps order
1378 * much better than a simple loop.
1380 * This algorithm zigzags over the caps structures as demonstrated in
1381 * the folowing matrix:
1389 * First we iterate over the caps1 structures (top line) intersecting
1390 * the structures diagonally down, then we iterate over the caps2
1393 len1 = caps1->structs->len;
1394 len2 = caps2->structs->len;
1395 for (i = 0; i < len1 + len2 - 1; i++) {
1396 /* caps1 index goes from 0 to caps1->structs->len-1 */
1397 j = MIN (i, len1 - 1);
1398 /* caps2 index stays 0 until i reaches caps1->structs->len, then it counts
1399 * up from 1 to caps2->structs->len - 1 */
1402 /* now run the diagonal line, end condition is the left or bottom
1405 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1406 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1408 istruct = gst_caps_structure_intersect (struct1, struct2);
1410 gst_caps_append_structure (dest, istruct);
1411 /* move down left */
1413 if (G_UNLIKELY (j == 0))
1414 break; /* so we don't roll back to G_MAXUINT */
1421 /* subtract operation */
1425 const GstStructure *subtract_from;
1431 gst_caps_structure_subtract_field (GQuark field_id, const GValue * value,
1434 SubtractionEntry *e = user_data;
1435 GValue subtraction = { 0, };
1436 const GValue *other;
1437 GstStructure *structure;
1439 other = gst_structure_id_get_value (e->subtract_from, field_id);
1443 if (!gst_value_subtract (&subtraction, other, value))
1445 if (gst_value_compare (&subtraction, other) == GST_VALUE_EQUAL) {
1446 g_value_unset (&subtraction);
1449 structure = gst_structure_copy (e->subtract_from);
1450 gst_structure_id_set_value (structure, field_id, &subtraction);
1451 g_value_unset (&subtraction);
1452 e->put_into = g_slist_prepend (e->put_into, structure);
1458 gst_caps_structure_subtract (GSList ** into, const GstStructure * minuend,
1459 const GstStructure * subtrahend)
1464 e.subtract_from = minuend;
1467 ret = gst_structure_foreach ((GstStructure *) subtrahend,
1468 gst_caps_structure_subtract_field, &e);
1474 for (walk = e.put_into; walk; walk = g_slist_next (walk)) {
1475 gst_structure_free (walk->data);
1477 g_slist_free (e.put_into);
1483 * gst_caps_subtract:
1484 * @minuend: #GstCaps to substract from
1485 * @subtrahend: #GstCaps to substract
1487 * Subtracts the @subtrahend from the @minuend.
1488 * <note>This function does not work reliably if optional properties for caps
1489 * are included on one caps and omitted on the other.</note>
1491 * Returns: the resulting caps
1494 gst_caps_subtract (const GstCaps * minuend, const GstCaps * subtrahend)
1499 GstCaps *dest = NULL, *src;
1501 g_return_val_if_fail (minuend != NULL, NULL);
1502 g_return_val_if_fail (subtrahend != NULL, NULL);
1504 if (CAPS_IS_EMPTY (minuend) || CAPS_IS_ANY (subtrahend)) {
1505 return gst_caps_new_empty ();
1507 if (CAPS_IS_EMPTY_SIMPLE (subtrahend))
1508 return _gst_caps_copy (minuend);
1510 /* FIXME: Do we want this here or above?
1511 The reason we need this is that there is no definition about what
1512 ANY means for specific types, so it's not possible to reduce ANY partially
1513 You can only remove everything or nothing and that is done above.
1514 Note: there's a test that checks this behaviour. */
1515 g_return_val_if_fail (!CAPS_IS_ANY (minuend), NULL);
1516 sublen = subtrahend->structs->len;
1517 g_assert (sublen > 0);
1519 src = _gst_caps_copy (minuend);
1520 for (i = 0; i < sublen; i++) {
1523 sub = gst_caps_get_structure_unchecked (subtrahend, i);
1525 gst_caps_unref (src);
1528 dest = gst_caps_new_empty ();
1529 srclen = src->structs->len;
1530 for (j = 0; j < srclen; j++) {
1531 min = gst_caps_get_structure_unchecked (src, j);
1532 if (gst_structure_get_name_id (min) == gst_structure_get_name_id (sub)) {
1535 if (gst_caps_structure_subtract (&list, min, sub)) {
1538 for (walk = list; walk; walk = g_slist_next (walk)) {
1539 gst_caps_append_structure_unchecked (dest,
1540 (GstStructure *) walk->data);
1542 g_slist_free (list);
1544 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1547 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1550 if (CAPS_IS_EMPTY_SIMPLE (dest)) {
1551 gst_caps_unref (src);
1556 gst_caps_unref (src);
1557 gst_caps_do_simplify (dest);
1561 /* union operation */
1564 static GstStructure *
1565 gst_caps_structure_union (const GstStructure * struct1,
1566 const GstStructure * struct2)
1570 const GstStructureField *field1;
1571 const GstStructureField *field2;
1574 /* FIXME this doesn't actually work */
1576 if (struct1->name != struct2->name)
1579 dest = gst_structure_id_empty_new (struct1->name);
1581 for (i = 0; i < struct1->fields->len; i++) {
1582 GValue dest_value = { 0 };
1584 field1 = GST_STRUCTURE_FIELD (struct1, i);
1585 field2 = gst_structure_id_get_field (struct2, field1->name);
1587 if (field2 == NULL) {
1590 if (gst_value_union (&dest_value, &field1->value, &field2->value)) {
1591 gst_structure_set_value (dest, g_quark_to_string (field1->name),
1594 ret = gst_value_compare (&field1->value, &field2->value);
1605 * @caps1: a #GstCaps to union
1606 * @caps2: a #GstCaps to union
1608 * Creates a new #GstCaps that contains all the formats that are in
1609 * either @caps1 and @caps2.
1611 * Returns: the new #GstCaps
1614 gst_caps_union (const GstCaps * caps1, const GstCaps * caps2)
1619 /* NULL pointers are no correct GstCaps */
1620 g_return_val_if_fail (caps1 != NULL, NULL);
1621 g_return_val_if_fail (caps2 != NULL, NULL);
1623 if (CAPS_IS_EMPTY (caps1))
1624 return _gst_caps_copy (caps2);
1626 if (CAPS_IS_EMPTY (caps2))
1627 return _gst_caps_copy (caps1);
1629 if (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))
1630 return gst_caps_new_any ();
1632 dest1 = _gst_caps_copy (caps1);
1633 dest2 = _gst_caps_copy (caps2);
1634 gst_caps_append (dest1, dest2);
1636 gst_caps_do_simplify (dest1);
1640 /* normalize/simplify operations */
1642 typedef struct _NormalizeForeach
1645 GstStructure *structure;
1650 gst_caps_normalize_foreach (GQuark field_id, const GValue * value, gpointer ptr)
1652 NormalizeForeach *nf = (NormalizeForeach *) ptr;
1656 if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
1657 guint len = gst_value_list_get_size (value);
1658 for (i = 1; i < len; i++) {
1659 const GValue *v = gst_value_list_get_value (value, i);
1660 GstStructure *structure = gst_structure_copy (nf->structure);
1662 gst_structure_id_set_value (structure, field_id, v);
1663 gst_caps_append_structure_unchecked (nf->caps, structure);
1666 gst_value_init_and_copy (&val, gst_value_list_get_value (value, 0));
1667 gst_structure_id_set_value (nf->structure, field_id, &val);
1668 g_value_unset (&val);
1676 * gst_caps_normalize:
1677 * @caps: a #GstCaps to normalize
1679 * Creates a new #GstCaps that represents the same set of formats as
1680 * @caps, but contains no lists. Each list is expanded into separate
1683 * Returns: the new #GstCaps
1686 gst_caps_normalize (const GstCaps * caps)
1688 NormalizeForeach nf;
1692 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
1694 newcaps = _gst_caps_copy (caps);
1697 for (i = 0; i < gst_caps_get_size (newcaps); i++) {
1698 nf.structure = gst_caps_get_structure_unchecked (newcaps, i);
1700 while (!gst_structure_foreach (nf.structure,
1701 gst_caps_normalize_foreach, &nf));
1708 gst_caps_compare_structures (gconstpointer one, gconstpointer two)
1711 const GstStructure *struct1 = *((const GstStructure **) one);
1712 const GstStructure *struct2 = *((const GstStructure **) two);
1714 /* FIXME: this orders alphabetically, but ordering the quarks might be faster
1715 So what's the best way? */
1716 ret = strcmp (gst_structure_get_name (struct1),
1717 gst_structure_get_name (struct2));
1721 return gst_structure_n_fields (struct2) - gst_structure_n_fields (struct1);
1728 GstStructure *compare;
1733 gst_caps_structure_figure_out_union (GQuark field_id, const GValue * value,
1736 UnionField *u = user_data;
1737 const GValue *val = gst_structure_id_get_value (u->compare, field_id);
1741 g_value_unset (&u->value);
1744 if (gst_value_compare (val, value) == GST_VALUE_EQUAL)
1747 g_value_unset (&u->value);
1751 gst_value_union (&u->value, val, value);
1756 gst_caps_structure_simplify (GstStructure ** result,
1757 const GstStructure * simplify, GstStructure * compare)
1760 UnionField field = { 0, {0,}, NULL };
1762 /* try to subtract to get a real subset */
1763 if (gst_caps_structure_subtract (&list, simplify, compare)) {
1764 if (list == NULL) { /* no result */
1767 } else if (list->next == NULL) { /* one result */
1768 *result = list->data;
1769 g_slist_free (list);
1771 } else { /* multiple results */
1772 g_slist_foreach (list, (GFunc) gst_structure_free, NULL);
1773 g_slist_free (list);
1778 /* try to union both structs */
1779 field.compare = compare;
1780 if (gst_structure_foreach ((GstStructure *) simplify,
1781 gst_caps_structure_figure_out_union, &field)) {
1782 gboolean ret = FALSE;
1784 /* now we know all of simplify's fields are the same in compare
1785 * but at most one field: field.name */
1786 if (G_IS_VALUE (&field.value)) {
1787 if (gst_structure_n_fields (simplify) == gst_structure_n_fields (compare)) {
1788 gst_structure_id_set_value (compare, field.name, &field.value);
1792 g_value_unset (&field.value);
1793 } else if (gst_structure_n_fields (simplify) <=
1794 gst_structure_n_fields (compare)) {
1795 /* compare is just more specific, will be optimized away later */
1796 /* FIXME: do this here? */
1797 GST_LOG ("found a case that will be optimized later.");
1799 gchar *one = gst_structure_to_string (simplify);
1800 gchar *two = gst_structure_to_string (compare);
1803 ("caps mismatch: structures %s and %s claim to be possible to unify, but aren't",
1815 gst_caps_switch_structures (GstCaps * caps, GstStructure * old,
1816 GstStructure * new, gint i)
1818 gst_structure_set_parent_refcount (old, NULL);
1819 gst_structure_free (old);
1820 gst_structure_set_parent_refcount (new, &GST_CAPS_REFCOUNT (caps));
1821 g_ptr_array_index (caps->structs, i) = new;
1825 * gst_caps_do_simplify:
1826 * @caps: a #GstCaps to simplify
1828 * Modifies the given @caps inplace into a representation that represents the
1829 * same set of formats, but in a simpler form. Component structures that are
1830 * identical are merged. Component structures that have values that can be
1831 * merged are also merged.
1833 * Returns: TRUE, if the caps could be simplified
1836 gst_caps_do_simplify (GstCaps * caps)
1838 GstStructure *simplify, *compare, *result = NULL;
1840 gboolean changed = FALSE;
1842 g_return_val_if_fail (caps != NULL, FALSE);
1843 g_return_val_if_fail (IS_WRITABLE (caps), FALSE);
1845 if (gst_caps_get_size (caps) < 2)
1848 g_ptr_array_sort (caps->structs, gst_caps_compare_structures);
1850 start = caps->structs->len - 1;
1851 for (i = caps->structs->len - 1; i >= 0; i--) {
1852 simplify = gst_caps_get_structure_unchecked (caps, i);
1853 if (gst_structure_get_name_id (simplify) !=
1854 gst_structure_get_name_id (gst_caps_get_structure_unchecked (caps,
1857 for (j = start; j >= 0; j--) {
1860 compare = gst_caps_get_structure_unchecked (caps, j);
1861 if (gst_structure_get_name_id (simplify) !=
1862 gst_structure_get_name_id (compare)) {
1865 if (gst_caps_structure_simplify (&result, simplify, compare)) {
1867 gst_caps_switch_structures (caps, simplify, result, i);
1870 gst_caps_remove_structure (caps, i);
1882 /* gst_caps_do_simplify (caps); */
1890 * @caps: (inout) (transfer full): a pointer to #GstCaps
1891 * @newcaps: a #GstCaps to replace *caps
1893 * Replaces *caps with @newcaps. Unrefs the #GstCaps in the location
1894 * pointed to by @caps, if applicable, then modifies @caps to point to
1895 * @newcaps. An additional ref on @newcaps is taken.
1897 * This function does not take any locks so you might want to lock
1898 * the object owning @caps pointer.
1901 gst_caps_replace (GstCaps ** caps, GstCaps * newcaps)
1905 g_return_if_fail (caps != NULL);
1909 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p, %p -> %p", caps, oldcaps, newcaps);
1911 if (newcaps != oldcaps) {
1913 gst_caps_ref (newcaps);
1918 gst_caps_unref (oldcaps);
1923 * gst_caps_to_string:
1926 * Converts @caps to a string representation. This string representation
1927 * can be converted back to a #GstCaps by gst_caps_from_string().
1929 * For debugging purposes its easier to do something like this:
1931 * GST_LOG ("caps are %" GST_PTR_FORMAT, caps);
1933 * This prints the caps in human readble form.
1935 * Returns: (transfer full): a newly allocated string representing @caps.
1938 gst_caps_to_string (const GstCaps * caps)
1940 guint i, slen, clen;
1943 /* NOTE: This function is potentially called by the debug system,
1944 * so any calls to gst_log() (and GST_DEBUG(), GST_LOG(), etc.)
1945 * should be careful to avoid recursion. This includes any functions
1946 * called by gst_caps_to_string. In particular, calls should
1947 * not use the GST_PTR_FORMAT extension. */
1950 return g_strdup ("NULL");
1952 if (CAPS_IS_ANY (caps)) {
1953 return g_strdup ("ANY");
1955 if (CAPS_IS_EMPTY_SIMPLE (caps)) {
1956 return g_strdup ("EMPTY");
1959 /* estimate a rough string length to avoid unnecessary reallocs in GString */
1961 clen = caps->structs->len;
1962 for (i = 0; i < clen; i++) {
1964 STRUCTURE_ESTIMATED_STRING_LEN (gst_caps_get_structure_unchecked (caps,
1968 s = g_string_sized_new (slen);
1969 for (i = 0; i < clen; i++) {
1970 GstStructure *structure;
1973 /* ';' is now added by gst_structure_to_string */
1974 g_string_append_c (s, ' ');
1977 structure = gst_caps_get_structure_unchecked (caps, i);
1978 priv_gst_structure_append_to_gstring (structure, s);
1980 if (s->len && s->str[s->len - 1] == ';') {
1981 /* remove latest ';' */
1982 s->str[--s->len] = '\0';
1984 return g_string_free (s, FALSE);
1988 gst_caps_from_string_inplace (GstCaps * caps, const gchar * string)
1990 GstStructure *structure;
1993 if (strcmp ("ANY", string) == 0) {
1994 GST_CAPS_FLAGS (caps) = GST_CAPS_FLAGS_ANY;
1997 if (strcmp ("EMPTY", string) == 0) {
2001 structure = gst_structure_from_string (string, &s);
2002 if (structure == NULL) {
2005 gst_caps_append_structure_unchecked (caps, structure);
2009 while (g_ascii_isspace (*s))
2014 structure = gst_structure_from_string (s, &s);
2015 if (structure == NULL) {
2018 gst_caps_append_structure_unchecked (caps, structure);
2026 * gst_caps_from_string:
2027 * @string: a string to convert to #GstCaps
2029 * Converts @caps from a string representation.
2031 * Returns: (transfer full): a newly allocated #GstCaps
2034 gst_caps_from_string (const gchar * string)
2038 g_return_val_if_fail (string, FALSE);
2040 caps = gst_caps_new_empty ();
2041 if (gst_caps_from_string_inplace (caps, string)) {
2044 gst_caps_unref (caps);
2050 gst_caps_transform_to_string (const GValue * src_value, GValue * dest_value)
2052 g_return_if_fail (G_IS_VALUE (src_value));
2053 g_return_if_fail (G_IS_VALUE (dest_value));
2054 g_return_if_fail (G_VALUE_HOLDS (src_value, GST_TYPE_CAPS));
2055 g_return_if_fail (G_VALUE_HOLDS (dest_value, G_TYPE_STRING)
2056 || G_VALUE_HOLDS (dest_value, G_TYPE_POINTER));
2058 dest_value->data[0].v_pointer =
2059 gst_caps_to_string (src_value->data[0].v_pointer);