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, &caps->refcount); \
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 ();
209 * gst_caps_new_empty:
211 * Creates a new #GstCaps that is empty. That is, the returned
212 * #GstCaps contains no media formats.
213 * Caller is responsible for unreffing the returned caps.
215 * Returns: (transfer full): the new #GstCaps
218 gst_caps_new_empty (void)
222 caps = g_slice_new (GstCaps);
224 gst_caps_init (caps);
226 #ifdef DEBUG_REFCOUNT
227 GST_CAT_LOG (GST_CAT_CAPS, "created caps %p", caps);
236 * Creates a new #GstCaps that indicates that it is compatible with
239 * Returns: (transfer full): the new #GstCaps
242 gst_caps_new_any (void)
244 GstCaps *caps = gst_caps_new_empty ();
246 GST_CAPS_FLAG_SET (caps, GST_CAPS_FLAGS_ANY);
252 * gst_caps_new_simple:
253 * @media_type: the media type of the structure
254 * @fieldname: first field to set
255 * @...: additional arguments
257 * Creates a new #GstCaps that contains one #GstStructure. The
258 * structure is defined by the arguments, which have the same format
259 * as gst_structure_new().
260 * Caller is responsible for unreffing the returned caps.
262 * Returns: (transfer full): the new #GstCaps
265 gst_caps_new_simple (const char *media_type, const char *fieldname, ...)
268 GstStructure *structure;
271 caps = gst_caps_new_empty ();
273 va_start (var_args, fieldname);
274 structure = gst_structure_new_valist (media_type, fieldname, var_args);
277 gst_caps_append_structure_unchecked (caps, structure);
284 * @struct1: the first structure to add
285 * @...: additional structures to add
287 * Creates a new #GstCaps and adds all the structures listed as
288 * arguments. The list must be NULL-terminated. The structures
289 * are not copied; the returned #GstCaps owns the structures.
291 * Returns: (transfer full): the new #GstCaps
294 gst_caps_new_full (GstStructure * struct1, ...)
299 va_start (var_args, struct1);
300 caps = gst_caps_new_full_valist (struct1, var_args);
307 * gst_caps_new_full_valist:
308 * @structure: the first structure to add
309 * @var_args: additional structures to add
311 * Creates a new #GstCaps and adds all the structures listed as
312 * arguments. The list must be NULL-terminated. The structures
313 * are not copied; the returned #GstCaps owns the structures.
315 * Returns: (transfer full): the new #GstCaps
318 gst_caps_new_full_valist (GstStructure * structure, va_list var_args)
322 caps = gst_caps_new_empty ();
325 gst_caps_append_structure_unchecked (caps, structure);
326 structure = va_arg (var_args, GstStructure *);
333 * gst_caps_make_writable:
334 * @caps: (transfer full): the #GstCaps to make writable
336 * Returns a writable copy of @caps.
338 * If there is only one reference count on @caps, the caller must be the owner,
339 * and so this function will return the caps object unchanged. If on the other
340 * hand there is more than one reference on the object, a new caps object will
341 * be returned. The caller's reference on @caps will be removed, and instead the
342 * caller will own a reference to the returned object.
344 * In short, this function unrefs the caps in the argument and refs the caps
345 * that it returns. Don't access the argument after calling this function. See
346 * also: gst_caps_ref().
348 * Returns: (transfer full): the same #GstCaps object.
351 gst_caps_make_writable (GstCaps * caps)
355 g_return_val_if_fail (caps != NULL, NULL);
357 /* we are the only instance reffing this caps */
358 if (IS_WRITABLE (caps))
362 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy caps");
363 copy = _gst_caps_copy (caps);
364 gst_caps_unref (caps);
370 gst_static_caps_get_type (void)
372 static GType staticcaps_type = 0;
374 if (G_UNLIKELY (staticcaps_type == 0)) {
375 staticcaps_type = g_pointer_type_register_static ("GstStaticCaps");
377 return staticcaps_type;
382 * gst_static_caps_get:
383 * @static_caps: the #GstStaticCaps to convert
385 * Converts a #GstStaticCaps to a #GstCaps.
387 * Returns: (transfer full): a pointer to the #GstCaps. Unref after usage.
388 * Since the core holds an additional ref to the returned caps,
389 * use gst_caps_make_writable() on the returned caps to modify it.
392 gst_static_caps_get (GstStaticCaps * static_caps)
396 g_return_val_if_fail (static_caps != NULL, NULL);
398 caps = (GstCaps *) static_caps;
400 /* refcount is 0 when we need to convert */
401 if (G_UNLIKELY (GST_CAPS_REFCOUNT_VALUE (caps) == 0)) {
405 G_LOCK (static_caps_lock);
406 /* check if other thread already updated */
407 if (G_UNLIKELY (GST_CAPS_REFCOUNT_VALUE (caps) > 0))
410 string = static_caps->string;
412 if (G_UNLIKELY (string == NULL))
415 GST_CAT_LOG (GST_CAT_CAPS, "creating %p", static_caps);
417 /* we construct the caps on the stack, then copy over the struct into our
418 * real caps, refcount last. We do this because we must leave the refcount
419 * of the result caps to 0 so that other threads don't run away with the
420 * caps while we are constructing it. */
421 gst_caps_init (&temp);
423 /* convert to string */
424 if (G_UNLIKELY (!gst_caps_from_string_inplace (&temp, string)))
425 g_critical ("Could not convert static caps \"%s\"", string);
427 gst_caps_init (caps);
428 /* now copy stuff over to the real caps. */
429 GST_CAPS_FLAGS (caps) = GST_CAPS_FLAGS (&temp);
430 caps->structs = temp.structs;
432 GST_CAT_LOG (GST_CAT_CAPS, "created %p", static_caps);
434 G_UNLOCK (static_caps_lock);
436 /* ref the caps, makes it not writable */
444 G_UNLOCK (static_caps_lock);
445 g_warning ("static caps %p string is NULL", static_caps);
452 static GstStructure *
453 gst_caps_remove_and_get_structure (GstCaps * caps, guint idx)
455 /* don't use index_fast, gst_caps_do_simplify relies on the order */
456 GstStructure *s = g_ptr_array_remove_index (caps->structs, idx);
458 gst_structure_set_parent_refcount (s, NULL);
463 * gst_caps_steal_structure:
464 * @caps: the #GstCaps to retrieve from
465 * @index: Index of the structure to retrieve
467 * Retrieves the stucture with the given index from the list of structures
468 * contained in @caps. The caller becomes the owner of the returned structure.
470 * Returns: (transfer full): a pointer to the #GstStructure corresponding
476 gst_caps_steal_structure (GstCaps * caps, guint index)
478 g_return_val_if_fail (caps != NULL, NULL);
479 g_return_val_if_fail (IS_WRITABLE (caps), NULL);
481 if (G_UNLIKELY (index >= caps->structs->len))
484 return gst_caps_remove_and_get_structure (caps, index);
488 gst_structure_is_equal_foreach (GQuark field_id, const GValue * val2,
491 GstStructure *struct1 = (GstStructure *) data;
492 const GValue *val1 = gst_structure_id_get_value (struct1, field_id);
494 if (G_UNLIKELY (val1 == NULL))
496 if (gst_value_compare (val1, val2) == GST_VALUE_EQUAL) {
504 gst_caps_structure_is_subset_field (GQuark field_id, const GValue * value,
507 GstStructure *subtract_from = user_data;
508 GValue subtraction = { 0, };
511 if (!(other = gst_structure_id_get_value (subtract_from, field_id)))
512 /* field is missing in one set */
515 /* equal values are subset */
516 if (gst_value_compare (other, value) == GST_VALUE_EQUAL)
524 * -> 1 - [1,2] = empty
528 * -> [1,2] - [1,3] = empty
532 * -> {1,3} - {1,2} = 3
535 * First caps subtraction needs to return a non-empty set, second
536 * subtractions needs to give en empty set.
538 if (gst_value_subtract (&subtraction, other, value)) {
539 g_value_unset (&subtraction);
540 /* !empty result, swapping must be empty */
541 if (!gst_value_subtract (&subtraction, value, other))
544 g_value_unset (&subtraction);
550 gst_caps_structure_is_subset (const GstStructure * minuend,
551 const GstStructure * subtrahend)
553 if ((minuend->name != subtrahend->name) ||
554 (gst_structure_n_fields (minuend) !=
555 gst_structure_n_fields (subtrahend))) {
559 return gst_structure_foreach ((GstStructure *) subtrahend,
560 gst_caps_structure_is_subset_field, (gpointer) minuend);
565 * @caps1: the #GstCaps that will be appended to
566 * @caps2: (transfer full): the #GstCaps to append
568 * Appends the structures contained in @caps2 to @caps1. The structures in
569 * @caps2 are not copied -- they are transferred to @caps1, and then @caps2 is
570 * freed. If either caps is ANY, the resulting caps will be ANY.
573 gst_caps_append (GstCaps * caps1, GstCaps * caps2)
575 GstStructure *structure;
578 g_return_if_fail (GST_IS_CAPS (caps1));
579 g_return_if_fail (GST_IS_CAPS (caps2));
580 g_return_if_fail (IS_WRITABLE (caps1));
581 g_return_if_fail (IS_WRITABLE (caps2));
586 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))) {
587 /* FIXME: this leaks */
588 GST_CAPS_FLAGS (caps1) |= GST_CAPS_FLAGS_ANY;
589 for (i = caps2->structs->len - 1; i >= 0; i--) {
590 structure = gst_caps_remove_and_get_structure (caps2, i);
591 gst_structure_free (structure);
594 for (i = caps2->structs->len; i; i--) {
595 structure = gst_caps_remove_and_get_structure (caps2, 0);
596 gst_caps_append_structure_unchecked (caps1, structure);
599 gst_caps_unref (caps2); /* guaranteed to free it */
604 * @caps1: the #GstCaps that will take the new entries
605 * @caps2: (transfer full): the #GstCaps to merge in
607 * Appends the structures contained in @caps2 to @caps1 if they are not yet
608 * expressed by @caps1. The structures in @caps2 are not copied -- they are
609 * transferred to @caps1, and then @caps2 is freed.
610 * If either caps is ANY, the resulting caps will be ANY.
615 gst_caps_merge (GstCaps * caps1, GstCaps * caps2)
617 GstStructure *structure;
620 g_return_if_fail (GST_IS_CAPS (caps1));
621 g_return_if_fail (GST_IS_CAPS (caps2));
622 g_return_if_fail (IS_WRITABLE (caps1));
623 g_return_if_fail (IS_WRITABLE (caps2));
628 if (G_UNLIKELY (CAPS_IS_ANY (caps1))) {
629 for (i = caps2->structs->len - 1; i >= 0; i--) {
630 structure = gst_caps_remove_and_get_structure (caps2, i);
631 gst_structure_free (structure);
633 } else if (G_UNLIKELY (CAPS_IS_ANY (caps2))) {
634 GST_CAPS_FLAGS (caps1) |= GST_CAPS_FLAGS_ANY;
635 for (i = caps1->structs->len - 1; i >= 0; i--) {
636 structure = gst_caps_remove_and_get_structure (caps1, i);
637 gst_structure_free (structure);
640 for (i = caps2->structs->len; i; i--) {
641 structure = gst_caps_remove_and_get_structure (caps2, 0);
642 gst_caps_merge_structure (caps1, structure);
645 GstCaps *com = gst_caps_intersect (caps1, caps2);
646 GstCaps *add = gst_caps_subtract (caps2, com);
648 GST_DEBUG ("common : %d", gst_caps_get_size (com));
649 GST_DEBUG ("adding : %d", gst_caps_get_size (add));
650 gst_caps_append (caps1, add);
651 gst_caps_unref (com);
654 gst_caps_unref (caps2); /* guaranteed to free it */
658 * gst_caps_append_structure:
659 * @caps: the #GstCaps that will be appended to
660 * @structure: (transfer full): the #GstStructure to append
662 * Appends @structure to @caps. The structure is not copied; @caps
663 * becomes the owner of @structure.
666 gst_caps_append_structure (GstCaps * caps, GstStructure * structure)
668 g_return_if_fail (GST_IS_CAPS (caps));
669 g_return_if_fail (IS_WRITABLE (caps));
671 if (G_LIKELY (structure)) {
672 g_return_if_fail (structure->parent_refcount == NULL);
675 STRUCTURE_POISON (structure);
678 gst_caps_append_structure_unchecked (caps, structure);
683 * gst_caps_remove_structure:
684 * @caps: the #GstCaps to remove from
685 * @idx: Index of the structure to remove
687 * removes the stucture with the given index from the list of structures
688 * contained in @caps.
691 gst_caps_remove_structure (GstCaps * caps, guint idx)
693 GstStructure *structure;
695 g_return_if_fail (caps != NULL);
696 g_return_if_fail (idx <= gst_caps_get_size (caps));
697 g_return_if_fail (IS_WRITABLE (caps));
699 structure = gst_caps_remove_and_get_structure (caps, idx);
700 gst_structure_free (structure);
704 * gst_caps_merge_structure:
705 * @caps: the #GstCaps that will the the new structure
706 * @structure: (transfer full): the #GstStructure to merge
708 * Appends @structure to @caps if its not already expressed by @caps. The
709 * structure is not copied; @caps becomes the owner of @structure.
712 gst_caps_merge_structure (GstCaps * caps, GstStructure * structure)
714 g_return_if_fail (GST_IS_CAPS (caps));
715 g_return_if_fail (IS_WRITABLE (caps));
717 if (G_LIKELY (structure)) {
718 GstStructure *structure1;
720 gboolean unique = TRUE;
722 g_return_if_fail (structure->parent_refcount == NULL);
725 STRUCTURE_POISON (structure);
728 /* check each structure */
729 for (i = caps->structs->len - 1; i >= 0; i--) {
730 structure1 = gst_caps_get_structure_unchecked (caps, i);
731 /* if structure is a subset of structure1, then skip it */
732 if (gst_caps_structure_is_subset (structure1, structure)) {
738 gst_caps_append_structure_unchecked (caps, structure);
740 gst_structure_free (structure);
749 * Gets the number of structures contained in @caps.
751 * Returns: the number of structures that @caps contains
754 gst_caps_get_size (const GstCaps * caps)
756 g_return_val_if_fail (GST_IS_CAPS (caps), 0);
758 return caps->structs->len;
762 * gst_caps_get_structure:
764 * @index: the index of the structure
766 * Finds the structure in @caps that has the index @index, and
769 * WARNING: This function takes a const GstCaps *, but returns a
770 * non-const GstStructure *. This is for programming convenience --
771 * the caller should be aware that structures inside a constant
772 * #GstCaps should not be modified. However, if you know the caps
773 * are writable, either because you have just copied them or made
774 * them writable with gst_caps_make_writable(), you may modify the
775 * structure returned in the usual way, e.g. with functions like
776 * gst_structure_set().
778 * You do not need to free or unref the structure returned, it
779 * belongs to the #GstCaps.
781 * Returns: (transfer none): a pointer to the #GstStructure corresponding
785 gst_caps_get_structure (const GstCaps * caps, guint index)
787 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
788 g_return_val_if_fail (index < caps->structs->len, NULL);
790 return gst_caps_get_structure_unchecked (caps, index);
795 * @caps: the #GstCaps to copy
796 * @nth: the nth structure to copy
798 * Creates a new #GstCaps and appends a copy of the nth structure
799 * contained in @caps.
801 * Returns: (transfer full): the new #GstCaps
804 gst_caps_copy_nth (const GstCaps * caps, guint nth)
807 GstStructure *structure;
809 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
811 newcaps = gst_caps_new_empty ();
812 GST_CAPS_FLAGS (newcaps) = GST_CAPS_FLAGS (caps);
814 if (G_LIKELY (caps->structs->len > nth)) {
815 structure = gst_caps_get_structure_unchecked (caps, nth);
816 gst_caps_append_structure_unchecked (newcaps,
817 gst_structure_copy (structure));
825 * @caps: the #GstCaps to truncate
827 * Destructively discard all but the first structure from @caps. Useful when
828 * fixating. @caps must be writable.
831 gst_caps_truncate (GstCaps * caps)
835 g_return_if_fail (GST_IS_CAPS (caps));
836 g_return_if_fail (IS_WRITABLE (caps));
838 i = caps->structs->len - 1;
841 gst_caps_remove_structure (caps, i--);
845 * gst_caps_set_value:
846 * @caps: a writable caps
847 * @field: name of the field to set
848 * @value: value to set the field to
850 * Sets the given @field on all structures of @caps to the given @value.
851 * This is a convenience function for calling gst_structure_set_value() on
852 * all structures of @caps.
857 gst_caps_set_value (GstCaps * caps, const char *field, const GValue * value)
861 g_return_if_fail (GST_IS_CAPS (caps));
862 g_return_if_fail (IS_WRITABLE (caps));
863 g_return_if_fail (field != NULL);
864 g_return_if_fail (G_IS_VALUE (value));
866 len = caps->structs->len;
867 for (i = 0; i < len; i++) {
868 GstStructure *structure = gst_caps_get_structure_unchecked (caps, i);
869 gst_structure_set_value (structure, field, value);
874 * gst_caps_set_simple_valist:
875 * @caps: the #GstCaps to set
876 * @field: first field to set
877 * @varargs: additional parameters
879 * Sets fields in a #GstCaps. The arguments must be passed in the same
880 * manner as gst_structure_set(), and be NULL-terminated.
881 * <note>Prior to GStreamer version 0.10.26, this function failed when
882 * @caps was not simple. If your code needs to work with those versions
883 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
884 * is %TRUE for @caps.</note>
887 gst_caps_set_simple_valist (GstCaps * caps, const char *field, va_list varargs)
889 GValue value = { 0, };
891 g_return_if_fail (GST_IS_CAPS (caps));
892 g_return_if_fail (IS_WRITABLE (caps));
898 type = va_arg (varargs, GType);
900 if (G_UNLIKELY (type == G_TYPE_DATE)) {
901 g_warning ("Don't use G_TYPE_DATE, use GST_TYPE_DATE instead\n");
902 type = GST_TYPE_DATE;
904 #if GLIB_CHECK_VERSION(2,23,3)
905 G_VALUE_COLLECT_INIT (&value, type, varargs, 0, &err);
907 g_value_init (&value, type);
908 G_VALUE_COLLECT (&value, varargs, 0, &err);
910 if (G_UNLIKELY (err)) {
911 g_critical ("%s", err);
915 gst_caps_set_value (caps, field, &value);
917 g_value_unset (&value);
919 field = va_arg (varargs, const gchar *);
924 * gst_caps_set_simple:
925 * @caps: the #GstCaps to set
926 * @field: first field to set
927 * @...: additional parameters
929 * Sets fields in a #GstCaps. The arguments must be passed in the same
930 * manner as gst_structure_set(), and be NULL-terminated.
931 * <note>Prior to GStreamer version 0.10.26, this function failed when
932 * @caps was not simple. If your code needs to work with those versions
933 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
934 * is %TRUE for @caps.</note>
937 gst_caps_set_simple (GstCaps * caps, const char *field, ...)
941 g_return_if_fail (GST_IS_CAPS (caps));
942 g_return_if_fail (IS_WRITABLE (caps));
944 va_start (var_args, field);
945 gst_caps_set_simple_valist (caps, field, var_args);
953 * @caps: the #GstCaps to test
955 * Determines if @caps represents any media format.
957 * Returns: TRUE if @caps represents any format.
960 gst_caps_is_any (const GstCaps * caps)
962 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
964 return (CAPS_IS_ANY (caps));
969 * @caps: the #GstCaps to test
971 * Determines if @caps represents no media formats.
973 * Returns: TRUE if @caps represents no formats.
976 gst_caps_is_empty (const GstCaps * caps)
978 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
980 if (CAPS_IS_ANY (caps))
983 return CAPS_IS_EMPTY_SIMPLE (caps);
987 gst_caps_is_fixed_foreach (GQuark field_id, const GValue * value,
990 return gst_value_is_fixed (value);
995 * @caps: the #GstCaps to test
997 * Fixed #GstCaps describe exactly one format, that is, they have exactly
998 * one structure, and each field in the structure describes a fixed type.
999 * Examples of non-fixed types are GST_TYPE_INT_RANGE and GST_TYPE_LIST.
1001 * Returns: TRUE if @caps is fixed
1004 gst_caps_is_fixed (const GstCaps * caps)
1006 GstStructure *structure;
1008 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1010 if (caps->structs->len != 1)
1013 structure = gst_caps_get_structure_unchecked (caps, 0);
1015 return gst_structure_foreach (structure, gst_caps_is_fixed_foreach, NULL);
1019 * gst_caps_is_equal_fixed:
1020 * @caps1: the #GstCaps to test
1021 * @caps2: the #GstCaps to test
1023 * Tests if two #GstCaps are equal. This function only works on fixed
1026 * Returns: TRUE if the arguments represent the same format
1029 gst_caps_is_equal_fixed (const GstCaps * caps1, const GstCaps * caps2)
1031 GstStructure *struct1, *struct2;
1033 g_return_val_if_fail (gst_caps_is_fixed (caps1), FALSE);
1034 g_return_val_if_fail (gst_caps_is_fixed (caps2), FALSE);
1036 struct1 = gst_caps_get_structure_unchecked (caps1, 0);
1037 struct2 = gst_caps_get_structure_unchecked (caps2, 0);
1039 if (struct1->name != struct2->name) {
1042 if (struct1->fields->len != struct2->fields->len) {
1046 return gst_structure_foreach (struct1, gst_structure_is_equal_foreach,
1051 * gst_caps_is_always_compatible:
1052 * @caps1: the #GstCaps to test
1053 * @caps2: the #GstCaps to test
1055 * A given #GstCaps structure is always compatible with another if
1056 * every media format that is in the first is also contained in the
1057 * second. That is, @caps1 is a subset of @caps2.
1059 * Returns: TRUE if @caps1 is a subset of @caps2.
1062 gst_caps_is_always_compatible (const GstCaps * caps1, const GstCaps * caps2)
1064 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1065 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1067 return gst_caps_is_subset (caps1, caps2);
1071 * gst_caps_is_subset:
1072 * @subset: a #GstCaps
1073 * @superset: a potentially greater #GstCaps
1075 * Checks if all caps represented by @subset are also represented by @superset.
1076 * <note>This function does not work reliably if optional properties for caps
1077 * are included on one caps and omitted on the other.</note>
1079 * Returns: %TRUE if @subset is a subset of @superset
1082 gst_caps_is_subset (const GstCaps * subset, const GstCaps * superset)
1087 g_return_val_if_fail (subset != NULL, FALSE);
1088 g_return_val_if_fail (superset != NULL, FALSE);
1090 if (CAPS_IS_EMPTY (subset) || CAPS_IS_ANY (superset))
1092 if (CAPS_IS_ANY (subset) || CAPS_IS_EMPTY (superset))
1095 caps = gst_caps_subtract (subset, superset);
1096 ret = CAPS_IS_EMPTY_SIMPLE (caps);
1097 gst_caps_unref (caps);
1102 * gst_caps_is_equal:
1103 * @caps1: a #GstCaps
1104 * @caps2: another #GstCaps
1106 * Checks if the given caps represent the same set of caps.
1107 * <note>This function does not work reliably if optional properties for caps
1108 * are included on one caps and omitted on the other.</note>
1110 * This function deals correctly with passing NULL for any of the caps.
1112 * Returns: TRUE if both caps are equal.
1115 gst_caps_is_equal (const GstCaps * caps1, const GstCaps * caps2)
1117 /* FIXME 0.11: NULL pointers are no valid Caps but indicate an error
1118 * So there should be an assertion that caps1 and caps2 != NULL */
1120 /* NULL <-> NULL is allowed here */
1121 if (G_UNLIKELY (caps1 == caps2))
1124 /* one of them NULL => they are different (can't be both NULL because
1125 * we checked that above) */
1126 if (G_UNLIKELY (caps1 == NULL || caps2 == NULL))
1129 if (G_UNLIKELY (gst_caps_is_fixed (caps1) && gst_caps_is_fixed (caps2)))
1130 return gst_caps_is_equal_fixed (caps1, caps2);
1132 return gst_caps_is_subset (caps1, caps2) && gst_caps_is_subset (caps2, caps1);
1135 /* intersect operation */
1140 const GstStructure *intersect;
1145 gst_caps_structure_intersect_field1 (GQuark id, const GValue * val1,
1148 IntersectData *idata = (IntersectData *) data;
1149 const GValue *val2 = gst_structure_id_get_value (idata->intersect, id);
1151 if (G_UNLIKELY (val2 == NULL)) {
1152 gst_structure_id_set_value (idata->dest, id, val1);
1154 GValue dest_value = { 0 };
1155 if (gst_value_intersect (&dest_value, val1, val2)) {
1156 gst_structure_id_set_value (idata->dest, id, &dest_value);
1157 g_value_unset (&dest_value);
1166 gst_caps_structure_intersect_field2 (GQuark id, const GValue * val1,
1169 IntersectData *idata = (IntersectData *) data;
1170 const GValue *val2 = gst_structure_id_get_value (idata->intersect, id);
1172 if (G_UNLIKELY (val2 == NULL)) {
1173 gst_structure_id_set_value (idata->dest, id, val1);
1178 static GstStructure *
1179 gst_caps_structure_intersect (const GstStructure * struct1,
1180 const GstStructure * struct2)
1184 g_assert (struct1 != NULL);
1185 g_assert (struct2 != NULL);
1187 if (G_UNLIKELY (struct1->name != struct2->name))
1190 /* copy fields from struct1 which we have not in struct2 to target
1191 * intersect if we have the field in both */
1192 data.dest = gst_structure_id_empty_new (struct1->name);
1193 data.intersect = struct2;
1194 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct1,
1195 gst_caps_structure_intersect_field1, &data)))
1198 /* copy fields from struct2 which we have not in struct1 to target */
1199 data.intersect = struct1;
1200 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct2,
1201 gst_caps_structure_intersect_field2, &data)))
1207 gst_structure_free (data.dest);
1212 gst_caps_structure_can_intersect_field (GQuark id, const GValue * val1,
1215 GstStructure *other = (GstStructure *) data;
1216 const GValue *val2 = gst_structure_id_get_value (other, id);
1218 if (G_LIKELY (val2)) {
1219 if (!gst_value_can_intersect (val1, val2)) {
1222 gint eq = gst_value_compare (val1, val2);
1224 if (eq == GST_VALUE_UNORDERED) {
1225 /* we need to try interseting */
1226 GValue dest_value = { 0 };
1227 if (gst_value_intersect (&dest_value, val1, val2)) {
1228 g_value_unset (&dest_value);
1232 } else if (eq != GST_VALUE_EQUAL) {
1241 gst_caps_structure_can_intersect (const GstStructure * struct1,
1242 const GstStructure * struct2)
1244 g_assert (struct1 != NULL);
1245 g_assert (struct2 != NULL);
1247 if (G_UNLIKELY (struct1->name != struct2->name))
1250 /* tries to intersect if we have the field in both */
1251 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct1,
1252 gst_caps_structure_can_intersect_field, (gpointer) struct2)))
1259 * gst_caps_can_intersect:
1260 * @caps1: a #GstCaps to intersect
1261 * @caps2: a #GstCaps to intersect
1263 * Tries intersecting @caps1 and @caps2 and reports whether the result would not
1266 * Returns: %TRUE if intersection would be not empty
1271 gst_caps_can_intersect (const GstCaps * caps1, const GstCaps * caps2)
1273 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1274 guint j, k, len1, len2;
1275 GstStructure *struct1;
1276 GstStructure *struct2;
1278 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1279 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1281 /* caps are exactly the same pointers */
1282 if (G_UNLIKELY (caps1 == caps2))
1285 /* empty caps on either side, return empty */
1286 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1289 /* one of the caps is any */
1290 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2)))
1293 /* run zigzag on top line then right line, this preserves the caps order
1294 * much better than a simple loop.
1296 * This algorithm zigzags over the caps structures as demonstrated in
1297 * the folowing matrix:
1300 * +------------- total distance: +-------------
1301 * | 1 2 4 7 0 | 0 1 2 3
1302 * caps2 | 3 5 8 10 1 | 1 2 3 4
1303 * | 6 9 11 12 2 | 2 3 4 5
1305 * First we iterate over the caps1 structures (top line) intersecting
1306 * the structures diagonally down, then we iterate over the caps2
1307 * structures. The result is that the intersections are ordered based on the
1308 * sum of the indexes in the list.
1310 len1 = caps1->structs->len;
1311 len2 = caps2->structs->len;
1312 for (i = 0; i < len1 + len2 - 1; i++) {
1313 /* superset index goes from 0 to sgst_caps_structure_intersectuperset->structs->len-1 */
1314 j = MIN (i, len1 - 1);
1315 /* subset index stays 0 until i reaches superset->structs->len, then it
1316 * counts up from 1 to subset->structs->len - 1 */
1319 /* now run the diagonal line, end condition is the left or bottom
1322 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1323 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1325 if (gst_caps_structure_can_intersect (struct1, struct2)) {
1328 /* move down left */
1330 if (G_UNLIKELY (j == 0))
1331 break; /* so we don't roll back to G_MAXUINT */
1339 * gst_caps_intersect:
1340 * @caps1: a #GstCaps to intersect
1341 * @caps2: a #GstCaps to intersect
1343 * Creates a new #GstCaps that contains all the formats that are common
1344 * to both @caps1 and @caps2.
1346 * Returns: the new #GstCaps
1349 gst_caps_intersect (const GstCaps * caps1, const GstCaps * caps2)
1351 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1352 guint j, k, len1, len2;
1354 GstStructure *struct1;
1355 GstStructure *struct2;
1357 GstStructure *istruct;
1359 g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
1360 g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
1362 /* caps are exactly the same pointers, just copy one caps */
1363 if (G_UNLIKELY (caps1 == caps2))
1364 return _gst_caps_copy (caps1);
1366 /* empty caps on either side, return empty */
1367 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1368 return gst_caps_new_empty ();
1370 /* one of the caps is any, just copy the other caps */
1371 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1372 return _gst_caps_copy (caps2);
1373 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1374 return _gst_caps_copy (caps1);
1376 dest = gst_caps_new_empty ();
1378 /* run zigzag on top line then right line, this preserves the caps order
1379 * much better than a simple loop.
1381 * This algorithm zigzags over the caps structures as demonstrated in
1382 * the folowing matrix:
1390 * First we iterate over the caps1 structures (top line) intersecting
1391 * the structures diagonally down, then we iterate over the caps2
1394 len1 = caps1->structs->len;
1395 len2 = caps2->structs->len;
1396 for (i = 0; i < len1 + len2 - 1; i++) {
1397 /* caps1 index goes from 0 to caps1->structs->len-1 */
1398 j = MIN (i, len1 - 1);
1399 /* caps2 index stays 0 until i reaches caps1->structs->len, then it counts
1400 * up from 1 to caps2->structs->len - 1 */
1403 /* now run the diagonal line, end condition is the left or bottom
1406 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1407 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1409 istruct = gst_caps_structure_intersect (struct1, struct2);
1411 gst_caps_append_structure (dest, istruct);
1412 /* move down left */
1414 if (G_UNLIKELY (j == 0))
1415 break; /* so we don't roll back to G_MAXUINT */
1422 /* subtract operation */
1426 const GstStructure *subtract_from;
1432 gst_caps_structure_subtract_field (GQuark field_id, const GValue * value,
1435 SubtractionEntry *e = user_data;
1436 GValue subtraction = { 0, };
1437 const GValue *other;
1438 GstStructure *structure;
1440 other = gst_structure_id_get_value (e->subtract_from, field_id);
1444 if (!gst_value_subtract (&subtraction, other, value))
1446 if (gst_value_compare (&subtraction, other) == GST_VALUE_EQUAL) {
1447 g_value_unset (&subtraction);
1450 structure = gst_structure_copy (e->subtract_from);
1451 gst_structure_id_set_value (structure, field_id, &subtraction);
1452 g_value_unset (&subtraction);
1453 e->put_into = g_slist_prepend (e->put_into, structure);
1459 gst_caps_structure_subtract (GSList ** into, const GstStructure * minuend,
1460 const GstStructure * subtrahend)
1465 e.subtract_from = minuend;
1468 ret = gst_structure_foreach ((GstStructure *) subtrahend,
1469 gst_caps_structure_subtract_field, &e);
1475 for (walk = e.put_into; walk; walk = g_slist_next (walk)) {
1476 gst_structure_free (walk->data);
1478 g_slist_free (e.put_into);
1484 * gst_caps_subtract:
1485 * @minuend: #GstCaps to substract from
1486 * @subtrahend: #GstCaps to substract
1488 * Subtracts the @subtrahend from the @minuend.
1489 * <note>This function does not work reliably if optional properties for caps
1490 * are included on one caps and omitted on the other.</note>
1492 * Returns: the resulting caps
1495 gst_caps_subtract (const GstCaps * minuend, const GstCaps * subtrahend)
1500 GstCaps *dest = NULL, *src;
1502 g_return_val_if_fail (minuend != NULL, NULL);
1503 g_return_val_if_fail (subtrahend != NULL, NULL);
1505 if (CAPS_IS_EMPTY (minuend) || CAPS_IS_ANY (subtrahend)) {
1506 return gst_caps_new_empty ();
1508 if (CAPS_IS_EMPTY_SIMPLE (subtrahend))
1509 return _gst_caps_copy (minuend);
1511 /* FIXME: Do we want this here or above?
1512 The reason we need this is that there is no definition about what
1513 ANY means for specific types, so it's not possible to reduce ANY partially
1514 You can only remove everything or nothing and that is done above.
1515 Note: there's a test that checks this behaviour. */
1516 g_return_val_if_fail (!CAPS_IS_ANY (minuend), NULL);
1517 sublen = subtrahend->structs->len;
1518 g_assert (sublen > 0);
1520 src = _gst_caps_copy (minuend);
1521 for (i = 0; i < sublen; i++) {
1524 sub = gst_caps_get_structure_unchecked (subtrahend, i);
1526 gst_caps_unref (src);
1529 dest = gst_caps_new_empty ();
1530 srclen = src->structs->len;
1531 for (j = 0; j < srclen; j++) {
1532 min = gst_caps_get_structure_unchecked (src, j);
1533 if (gst_structure_get_name_id (min) == gst_structure_get_name_id (sub)) {
1536 if (gst_caps_structure_subtract (&list, min, sub)) {
1539 for (walk = list; walk; walk = g_slist_next (walk)) {
1540 gst_caps_append_structure_unchecked (dest,
1541 (GstStructure *) walk->data);
1543 g_slist_free (list);
1545 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1548 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1551 if (CAPS_IS_EMPTY_SIMPLE (dest)) {
1552 gst_caps_unref (src);
1557 gst_caps_unref (src);
1558 gst_caps_do_simplify (dest);
1562 /* union operation */
1565 static GstStructure *
1566 gst_caps_structure_union (const GstStructure * struct1,
1567 const GstStructure * struct2)
1571 const GstStructureField *field1;
1572 const GstStructureField *field2;
1575 /* FIXME this doesn't actually work */
1577 if (struct1->name != struct2->name)
1580 dest = gst_structure_id_empty_new (struct1->name);
1582 for (i = 0; i < struct1->fields->len; i++) {
1583 GValue dest_value = { 0 };
1585 field1 = GST_STRUCTURE_FIELD (struct1, i);
1586 field2 = gst_structure_id_get_field (struct2, field1->name);
1588 if (field2 == NULL) {
1591 if (gst_value_union (&dest_value, &field1->value, &field2->value)) {
1592 gst_structure_set_value (dest, g_quark_to_string (field1->name),
1595 ret = gst_value_compare (&field1->value, &field2->value);
1606 * @caps1: a #GstCaps to union
1607 * @caps2: a #GstCaps to union
1609 * Creates a new #GstCaps that contains all the formats that are in
1610 * either @caps1 and @caps2.
1612 * Returns: the new #GstCaps
1615 gst_caps_union (const GstCaps * caps1, const GstCaps * caps2)
1620 /* NULL pointers are no correct GstCaps */
1621 g_return_val_if_fail (caps1 != NULL, NULL);
1622 g_return_val_if_fail (caps2 != NULL, NULL);
1624 if (CAPS_IS_EMPTY (caps1))
1625 return _gst_caps_copy (caps2);
1627 if (CAPS_IS_EMPTY (caps2))
1628 return _gst_caps_copy (caps1);
1630 if (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))
1631 return gst_caps_new_any ();
1633 dest1 = _gst_caps_copy (caps1);
1634 dest2 = _gst_caps_copy (caps2);
1635 gst_caps_append (dest1, dest2);
1637 gst_caps_do_simplify (dest1);
1641 /* normalize/simplify operations */
1643 typedef struct _NormalizeForeach
1646 GstStructure *structure;
1651 gst_caps_normalize_foreach (GQuark field_id, const GValue * value, gpointer ptr)
1653 NormalizeForeach *nf = (NormalizeForeach *) ptr;
1657 if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
1658 guint len = gst_value_list_get_size (value);
1659 for (i = 1; i < len; i++) {
1660 const GValue *v = gst_value_list_get_value (value, i);
1661 GstStructure *structure = gst_structure_copy (nf->structure);
1663 gst_structure_id_set_value (structure, field_id, v);
1664 gst_caps_append_structure_unchecked (nf->caps, structure);
1667 gst_value_init_and_copy (&val, gst_value_list_get_value (value, 0));
1668 gst_structure_id_set_value (nf->structure, field_id, &val);
1669 g_value_unset (&val);
1677 * gst_caps_normalize:
1678 * @caps: a #GstCaps to normalize
1680 * Creates a new #GstCaps that represents the same set of formats as
1681 * @caps, but contains no lists. Each list is expanded into separate
1684 * Returns: the new #GstCaps
1687 gst_caps_normalize (const GstCaps * caps)
1689 NormalizeForeach nf;
1693 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
1695 newcaps = _gst_caps_copy (caps);
1698 for (i = 0; i < gst_caps_get_size (newcaps); i++) {
1699 nf.structure = gst_caps_get_structure_unchecked (newcaps, i);
1701 while (!gst_structure_foreach (nf.structure,
1702 gst_caps_normalize_foreach, &nf));
1709 gst_caps_compare_structures (gconstpointer one, gconstpointer two)
1712 const GstStructure *struct1 = *((const GstStructure **) one);
1713 const GstStructure *struct2 = *((const GstStructure **) two);
1715 /* FIXME: this orders alphabetically, but ordering the quarks might be faster
1716 So what's the best way? */
1717 ret = strcmp (gst_structure_get_name (struct1),
1718 gst_structure_get_name (struct2));
1722 return gst_structure_n_fields (struct2) - gst_structure_n_fields (struct1);
1729 GstStructure *compare;
1734 gst_caps_structure_figure_out_union (GQuark field_id, const GValue * value,
1737 UnionField *u = user_data;
1738 const GValue *val = gst_structure_id_get_value (u->compare, field_id);
1742 g_value_unset (&u->value);
1745 if (gst_value_compare (val, value) == GST_VALUE_EQUAL)
1748 g_value_unset (&u->value);
1752 gst_value_union (&u->value, val, value);
1757 gst_caps_structure_simplify (GstStructure ** result,
1758 const GstStructure * simplify, GstStructure * compare)
1761 UnionField field = { 0, {0,}, NULL };
1763 /* try to subtract to get a real subset */
1764 if (gst_caps_structure_subtract (&list, simplify, compare)) {
1765 if (list == NULL) { /* no result */
1768 } else if (list->next == NULL) { /* one result */
1769 *result = list->data;
1770 g_slist_free (list);
1772 } else { /* multiple results */
1773 g_slist_foreach (list, (GFunc) gst_structure_free, NULL);
1774 g_slist_free (list);
1779 /* try to union both structs */
1780 field.compare = compare;
1781 if (gst_structure_foreach ((GstStructure *) simplify,
1782 gst_caps_structure_figure_out_union, &field)) {
1783 gboolean ret = FALSE;
1785 /* now we know all of simplify's fields are the same in compare
1786 * but at most one field: field.name */
1787 if (G_IS_VALUE (&field.value)) {
1788 if (gst_structure_n_fields (simplify) == gst_structure_n_fields (compare)) {
1789 gst_structure_id_set_value (compare, field.name, &field.value);
1793 g_value_unset (&field.value);
1794 } else if (gst_structure_n_fields (simplify) <=
1795 gst_structure_n_fields (compare)) {
1796 /* compare is just more specific, will be optimized away later */
1797 /* FIXME: do this here? */
1798 GST_LOG ("found a case that will be optimized later.");
1800 gchar *one = gst_structure_to_string (simplify);
1801 gchar *two = gst_structure_to_string (compare);
1804 ("caps mismatch: structures %s and %s claim to be possible to unify, but aren't",
1816 gst_caps_switch_structures (GstCaps * caps, GstStructure * old,
1817 GstStructure * new, gint i)
1819 gst_structure_set_parent_refcount (old, NULL);
1820 gst_structure_free (old);
1821 gst_structure_set_parent_refcount (new, &GST_CAPS_REFCOUNT (caps));
1822 g_ptr_array_index (caps->structs, i) = new;
1826 * gst_caps_do_simplify:
1827 * @caps: a #GstCaps to simplify
1829 * Modifies the given @caps inplace into a representation that represents the
1830 * same set of formats, but in a simpler form. Component structures that are
1831 * identical are merged. Component structures that have values that can be
1832 * merged are also merged.
1834 * Returns: TRUE, if the caps could be simplified
1837 gst_caps_do_simplify (GstCaps * caps)
1839 GstStructure *simplify, *compare, *result = NULL;
1841 gboolean changed = FALSE;
1843 g_return_val_if_fail (caps != NULL, FALSE);
1844 g_return_val_if_fail (IS_WRITABLE (caps), FALSE);
1846 if (gst_caps_get_size (caps) < 2)
1849 g_ptr_array_sort (caps->structs, gst_caps_compare_structures);
1851 start = caps->structs->len - 1;
1852 for (i = caps->structs->len - 1; i >= 0; i--) {
1853 simplify = gst_caps_get_structure_unchecked (caps, i);
1854 if (gst_structure_get_name_id (simplify) !=
1855 gst_structure_get_name_id (gst_caps_get_structure_unchecked (caps,
1858 for (j = start; j >= 0; j--) {
1861 compare = gst_caps_get_structure_unchecked (caps, j);
1862 if (gst_structure_get_name_id (simplify) !=
1863 gst_structure_get_name_id (compare)) {
1866 if (gst_caps_structure_simplify (&result, simplify, compare)) {
1868 gst_caps_switch_structures (caps, simplify, result, i);
1871 gst_caps_remove_structure (caps, i);
1883 /* gst_caps_do_simplify (caps); */
1891 * @caps: (inout) (transfer full): a pointer to #GstCaps
1892 * @newcaps: a #GstCaps to replace *caps
1894 * Replaces *caps with @newcaps. Unrefs the #GstCaps in the location
1895 * pointed to by @caps, if applicable, then modifies @caps to point to
1896 * @newcaps. An additional ref on @newcaps is taken.
1898 * This function does not take any locks so you might want to lock
1899 * the object owning @caps pointer.
1902 gst_caps_replace (GstCaps ** caps, GstCaps * newcaps)
1906 g_return_if_fail (caps != NULL);
1910 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p, %p -> %p", caps, oldcaps, newcaps);
1912 if (newcaps != oldcaps) {
1914 gst_caps_ref (newcaps);
1919 gst_caps_unref (oldcaps);
1924 * gst_caps_to_string:
1927 * Converts @caps to a string representation. This string representation
1928 * can be converted back to a #GstCaps by gst_caps_from_string().
1930 * For debugging purposes its easier to do something like this:
1932 * GST_LOG ("caps are %" GST_PTR_FORMAT, caps);
1934 * This prints the caps in human readble form.
1936 * Returns: (transfer full): a newly allocated string representing @caps.
1939 gst_caps_to_string (const GstCaps * caps)
1941 guint i, slen, clen;
1944 /* NOTE: This function is potentially called by the debug system,
1945 * so any calls to gst_log() (and GST_DEBUG(), GST_LOG(), etc.)
1946 * should be careful to avoid recursion. This includes any functions
1947 * called by gst_caps_to_string. In particular, calls should
1948 * not use the GST_PTR_FORMAT extension. */
1951 return g_strdup ("NULL");
1953 if (CAPS_IS_ANY (caps)) {
1954 return g_strdup ("ANY");
1956 if (CAPS_IS_EMPTY_SIMPLE (caps)) {
1957 return g_strdup ("EMPTY");
1960 /* estimate a rough string length to avoid unnecessary reallocs in GString */
1962 clen = caps->structs->len;
1963 for (i = 0; i < clen; i++) {
1965 STRUCTURE_ESTIMATED_STRING_LEN (gst_caps_get_structure_unchecked (caps,
1969 s = g_string_sized_new (slen);
1970 for (i = 0; i < clen; i++) {
1971 GstStructure *structure;
1974 /* ';' is now added by gst_structure_to_string */
1975 g_string_append_c (s, ' ');
1978 structure = gst_caps_get_structure_unchecked (caps, i);
1979 priv_gst_structure_append_to_gstring (structure, s);
1981 if (s->len && s->str[s->len - 1] == ';') {
1982 /* remove latest ';' */
1983 s->str[--s->len] = '\0';
1985 return g_string_free (s, FALSE);
1989 gst_caps_from_string_inplace (GstCaps * caps, const gchar * string)
1991 GstStructure *structure;
1994 if (strcmp ("ANY", string) == 0) {
1995 GST_CAPS_FLAGS (caps) = GST_CAPS_FLAGS_ANY;
1998 if (strcmp ("EMPTY", string) == 0) {
2002 structure = gst_structure_from_string (string, &s);
2003 if (structure == NULL) {
2006 gst_caps_append_structure_unchecked (caps, structure);
2010 while (g_ascii_isspace (*s))
2015 structure = gst_structure_from_string (s, &s);
2016 if (structure == NULL) {
2019 gst_caps_append_structure_unchecked (caps, structure);
2027 * gst_caps_from_string:
2028 * @string: a string to convert to #GstCaps
2030 * Converts @caps from a string representation.
2032 * Returns: (transfer full): a newly allocated #GstCaps
2035 gst_caps_from_string (const gchar * string)
2039 g_return_val_if_fail (string, FALSE);
2041 caps = gst_caps_new_empty ();
2042 if (gst_caps_from_string_inplace (caps, string)) {
2045 gst_caps_unref (caps);
2051 gst_caps_transform_to_string (const GValue * src_value, GValue * dest_value)
2053 g_return_if_fail (G_IS_VALUE (src_value));
2054 g_return_if_fail (G_IS_VALUE (dest_value));
2055 g_return_if_fail (G_VALUE_HOLDS (src_value, GST_TYPE_CAPS));
2056 g_return_if_fail (G_VALUE_HOLDS (dest_value, G_TYPE_STRING)
2057 || G_VALUE_HOLDS (dest_value, G_TYPE_POINTER));
2059 dest_value->data[0].v_pointer =
2060 gst_caps_to_string (src_value->data[0].v_pointer);