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 (g_atomic_int_get (&(caps)->refcount) == 1)
95 /* same as gst_caps_is_any () */
96 #define CAPS_IS_ANY(caps) \
97 ((caps)->flags & 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);
124 static GstCaps *gst_caps_copy_conditional (GstCaps * src);
127 gst_caps_get_type (void)
129 static GType gst_caps_type = 0;
131 if (G_UNLIKELY (gst_caps_type == 0)) {
132 gst_caps_type = g_boxed_type_register_static ("GstCaps",
133 (GBoxedCopyFunc) gst_caps_copy_conditional,
134 (GBoxedFreeFunc) gst_caps_unref);
136 g_value_register_transform_func (gst_caps_type,
137 G_TYPE_STRING, gst_caps_transform_to_string);
140 return gst_caps_type;
143 /* creation/deletion */
145 _gst_caps_free (GstCaps * caps)
147 GstStructure *structure;
150 /* The refcount must be 0, but since we're only called by gst_caps_unref,
151 * don't bother testing. */
152 len = caps->structs->len;
153 /* This can be used to get statistics about caps sizes */
154 /*GST_CAT_INFO (GST_CAT_CAPS, "caps size: %d", len); */
155 for (i = 0; i < len; i++) {
156 structure = (GstStructure *) gst_caps_get_structure_unchecked (caps, i);
157 gst_structure_set_parent_refcount (structure, NULL);
158 gst_structure_free (structure);
160 g_ptr_array_free (caps->structs, TRUE);
162 memset (caps, 0xff, sizeof (GstCaps));
165 #ifdef DEBUG_REFCOUNT
166 GST_CAT_LOG (GST_CAT_CAPS, "freeing caps %p", caps);
168 g_slice_free (GstCaps, caps);
172 * gst_caps_new_empty:
174 * Creates a new #GstCaps that is empty. That is, the returned
175 * #GstCaps contains no media formats.
176 * Caller is responsible for unreffing the returned caps.
178 * Returns: (transfer full): the new #GstCaps
181 gst_caps_new_empty (void)
183 GstCaps *caps = g_slice_new (GstCaps);
185 gst_mini_object_init (GST_MINI_OBJECT_CAST (caps),
186 GST_TYPE_CAPS, sizeof (GstCaps));
188 caps->mini_object.copy = (GstMiniObjectCopyFunction) gst_caps_copy;
189 caps->mini_object.free = (GstMiniObjectFreeFunction) _gst_caps_free;
191 caps->structs = g_ptr_array_new ();
192 /* the 32 has been determined by logging caps sizes in _gst_caps_free
193 * but g_ptr_array uses 16 anyway if it expands once, so this does not help
195 * caps->structs = g_ptr_array_sized_new (32);
198 #ifdef DEBUG_REFCOUNT
199 GST_CAT_LOG (GST_CAT_CAPS, "created caps %p", caps);
208 * Creates a new #GstCaps that indicates that it is compatible with
211 * Returns: (transfer full): the new #GstCaps
214 gst_caps_new_any (void)
216 GstCaps *caps = gst_caps_new_empty ();
218 GST_CAPS_FLAG_SET (caps, GST_CAPS_FLAGS_ANY);
224 * gst_caps_new_simple:
225 * @media_type: the media type of the structure
226 * @fieldname: first field to set
227 * @...: additional arguments
229 * Creates a new #GstCaps that contains one #GstStructure. The
230 * structure is defined by the arguments, which have the same format
231 * as gst_structure_new().
232 * Caller is responsible for unreffing the returned caps.
234 * Returns: (transfer full): the new #GstCaps
237 gst_caps_new_simple (const char *media_type, const char *fieldname, ...)
240 GstStructure *structure;
243 caps = gst_caps_new_empty ();
245 va_start (var_args, fieldname);
246 structure = gst_structure_new_valist (media_type, fieldname, var_args);
249 gst_caps_append_structure_unchecked (caps, structure);
256 * @struct1: the first structure to add
257 * @...: additional structures to add
259 * Creates a new #GstCaps and adds all the structures listed as
260 * arguments. The list must be NULL-terminated. The structures
261 * are not copied; the returned #GstCaps owns the structures.
263 * Returns: (transfer full): the new #GstCaps
266 gst_caps_new_full (GstStructure * struct1, ...)
271 va_start (var_args, struct1);
272 caps = gst_caps_new_full_valist (struct1, var_args);
279 * gst_caps_new_full_valist:
280 * @structure: the first structure to add
281 * @var_args: additional structures to add
283 * Creates a new #GstCaps and adds all the structures listed as
284 * arguments. The list must be NULL-terminated. The structures
285 * are not copied; the returned #GstCaps owns the structures.
287 * Returns: (transfer full): the new #GstCaps
290 gst_caps_new_full_valist (GstStructure * structure, va_list var_args)
294 caps = gst_caps_new_empty ();
297 gst_caps_append_structure_unchecked (caps, structure);
298 structure = va_arg (var_args, GstStructure *);
306 * @caps: the #GstCaps to copy
308 * Creates a new #GstCaps as a copy of the old @caps. The new caps will have a
309 * refcount of 1, owned by the caller. The structures are copied as well.
311 * Note that this function is the semantic equivalent of a gst_caps_ref()
312 * followed by a gst_caps_make_writable(). If you only want to hold on to a
313 * reference to the data, you should use gst_caps_ref().
315 * When you are finished with the caps, call gst_caps_unref() on it.
317 * Returns: (transfer full): the new #GstCaps
320 gst_caps_copy (const GstCaps * caps)
323 GstStructure *structure;
326 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
328 newcaps = gst_caps_new_empty ();
329 newcaps->flags = caps->flags;
330 n = caps->structs->len;
332 for (i = 0; i < n; i++) {
333 structure = gst_caps_get_structure_unchecked (caps, i);
334 gst_caps_append_structure_unchecked (newcaps,
335 gst_structure_copy (structure));
342 * gst_caps_make_writable:
343 * @caps: (transfer full): the #GstCaps to make writable
345 * Returns a writable copy of @caps.
347 * If there is only one reference count on @caps, the caller must be the owner,
348 * and so this function will return the caps object unchanged. If on the other
349 * hand there is more than one reference on the object, a new caps object will
350 * be returned. The caller's reference on @caps will be removed, and instead the
351 * caller will own a reference to the returned object.
353 * In short, this function unrefs the caps in the argument and refs the caps
354 * that it returns. Don't access the argument after calling this function. See
355 * also: gst_caps_ref().
357 * Returns: (transfer full): the same #GstCaps object.
360 gst_caps_make_writable (GstCaps * caps)
364 g_return_val_if_fail (caps != NULL, NULL);
366 /* we are the only instance reffing this caps */
367 if (IS_WRITABLE (caps))
371 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy caps");
372 copy = gst_caps_copy (caps);
373 gst_caps_unref (caps);
380 * @caps: the #GstCaps to reference
382 * Add a reference to a #GstCaps object.
384 * From this point on, until the caller calls gst_caps_unref() or
385 * gst_caps_make_writable(), it is guaranteed that the caps object will not
386 * change. This means its structures won't change, etc. To use a #GstCaps
387 * object, you must always have a refcount on it -- either the one made
388 * implicitly by e.g. gst_caps_new_simple(), or via taking one explicitly with
391 * Returns: (transfer full): the same #GstCaps object.
394 gst_caps_ref (GstCaps * caps)
396 g_return_val_if_fail (caps != NULL, NULL);
398 #ifdef DEBUG_REFCOUNT
399 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p %d->%d", caps,
400 GST_CAPS_REFCOUNT_VALUE (caps), GST_CAPS_REFCOUNT_VALUE (caps) + 1);
402 g_return_val_if_fail (GST_CAPS_REFCOUNT_VALUE (caps) > 0, NULL);
404 g_atomic_int_inc (&caps->refcount);
411 * @caps: (transfer full): the #GstCaps to unref
413 * Unref a #GstCaps and and free all its structures and the
414 * structures' values when the refcount reaches 0.
417 gst_caps_unref (GstCaps * caps)
419 g_return_if_fail (caps != NULL);
421 #ifdef DEBUG_REFCOUNT
422 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p %d->%d", caps,
423 GST_CAPS_REFCOUNT_VALUE (caps), GST_CAPS_REFCOUNT_VALUE (caps) - 1);
426 g_return_if_fail (GST_CAPS_REFCOUNT_VALUE (caps) > 0);
428 /* if we ended up with the refcount at zero, free the caps */
429 if (G_UNLIKELY (g_atomic_int_dec_and_test (&caps->refcount)))
430 _gst_caps_free (caps);
434 gst_static_caps_get_type (void)
436 static GType staticcaps_type = 0;
438 if (G_UNLIKELY (staticcaps_type == 0)) {
439 staticcaps_type = g_pointer_type_register_static ("GstStaticCaps");
441 return staticcaps_type;
446 * gst_static_caps_get:
447 * @static_caps: the #GstStaticCaps to convert
449 * Converts a #GstStaticCaps to a #GstCaps.
451 * Returns: (transfer full): a pointer to the #GstCaps. Unref after usage.
452 * Since the core holds an additional ref to the returned caps,
453 * use gst_caps_make_writable() on the returned caps to modify it.
456 gst_static_caps_get (GstStaticCaps * static_caps)
460 g_return_val_if_fail (static_caps != NULL, NULL);
462 caps = (GstCaps *) static_caps;
464 /* refcount is 0 when we need to convert */
465 if (G_UNLIKELY (g_atomic_int_get (&caps->refcount) == 0)) {
469 G_LOCK (static_caps_lock);
470 /* check if other thread already updated */
471 if (G_UNLIKELY (g_atomic_int_get (&caps->refcount) > 0))
474 string = static_caps->string;
476 if (G_UNLIKELY (string == NULL))
479 GST_CAT_LOG (GST_CAT_CAPS, "creating %p", static_caps);
481 /* we construct the caps on the stack, then copy over the struct into our
482 * real caps, refcount last. We do this because we must leave the refcount
483 * of the result caps to 0 so that other threads don't run away with the
484 * caps while we are constructing it. */
485 temp.type = GST_TYPE_CAPS;
487 temp.structs = g_ptr_array_new ();
489 /* initialize the caps to a refcount of 1 so the caps can be writable for
490 * the next statement */
493 /* convert to string */
494 if (G_UNLIKELY (!gst_caps_from_string_inplace (&temp, string)))
495 g_critical ("Could not convert static caps \"%s\"", string);
497 /* now copy stuff over to the real caps. */
498 caps->type = temp.type;
499 caps->flags = temp.flags;
500 caps->structs = temp.structs;
501 /* and bump the refcount so other threads can now read */
502 g_atomic_int_set (&caps->refcount, 1);
504 GST_CAT_LOG (GST_CAT_CAPS, "created %p", static_caps);
506 G_UNLOCK (static_caps_lock);
508 /* ref the caps, makes it not writable */
516 G_UNLOCK (static_caps_lock);
517 g_warning ("static caps %p string is NULL", static_caps);
524 static GstStructure *
525 gst_caps_remove_and_get_structure (GstCaps * caps, guint idx)
527 /* don't use index_fast, gst_caps_do_simplify relies on the order */
528 GstStructure *s = g_ptr_array_remove_index (caps->structs, idx);
530 gst_structure_set_parent_refcount (s, NULL);
535 * gst_caps_steal_structure:
536 * @caps: the #GstCaps to retrieve from
537 * @index: Index of the structure to retrieve
539 * Retrieves the stucture with the given index from the list of structures
540 * contained in @caps. The caller becomes the owner of the returned structure.
542 * Returns: (transfer full): a pointer to the #GstStructure corresponding
548 gst_caps_steal_structure (GstCaps * caps, guint index)
550 g_return_val_if_fail (caps != NULL, NULL);
551 g_return_val_if_fail (IS_WRITABLE (caps), NULL);
553 if (G_UNLIKELY (index >= caps->structs->len))
556 return gst_caps_remove_and_get_structure (caps, index);
560 gst_structure_is_equal_foreach (GQuark field_id, const GValue * val2,
563 GstStructure *struct1 = (GstStructure *) data;
564 const GValue *val1 = gst_structure_id_get_value (struct1, field_id);
566 if (G_UNLIKELY (val1 == NULL))
568 if (gst_value_compare (val1, val2) == GST_VALUE_EQUAL) {
576 gst_caps_structure_is_subset_field (GQuark field_id, const GValue * value,
579 GstStructure *subtract_from = user_data;
580 GValue subtraction = { 0, };
583 if (!(other = gst_structure_id_get_value (subtract_from, field_id)))
584 /* field is missing in one set */
587 /* equal values are subset */
588 if (gst_value_compare (other, value) == GST_VALUE_EQUAL)
596 * -> 1 - [1,2] = empty
600 * -> [1,2] - [1,3] = empty
604 * -> {1,3} - {1,2} = 3
607 * First caps subtraction needs to return a non-empty set, second
608 * subtractions needs to give en empty set.
610 if (gst_value_subtract (&subtraction, other, value)) {
611 g_value_unset (&subtraction);
612 /* !empty result, swapping must be empty */
613 if (!gst_value_subtract (&subtraction, value, other))
616 g_value_unset (&subtraction);
622 gst_caps_structure_is_subset (const GstStructure * minuend,
623 const GstStructure * subtrahend)
625 if ((minuend->name != subtrahend->name) ||
626 (gst_structure_n_fields (minuend) !=
627 gst_structure_n_fields (subtrahend))) {
631 return gst_structure_foreach ((GstStructure *) subtrahend,
632 gst_caps_structure_is_subset_field, (gpointer) minuend);
637 * @caps1: the #GstCaps that will be appended to
638 * @caps2: (transfer full): the #GstCaps to append
640 * Appends the structures contained in @caps2 to @caps1. The structures in
641 * @caps2 are not copied -- they are transferred to @caps1, and then @caps2 is
642 * freed. If either caps is ANY, the resulting caps will be ANY.
645 gst_caps_append (GstCaps * caps1, GstCaps * caps2)
647 GstStructure *structure;
650 g_return_if_fail (GST_IS_CAPS (caps1));
651 g_return_if_fail (GST_IS_CAPS (caps2));
652 g_return_if_fail (IS_WRITABLE (caps1));
653 g_return_if_fail (IS_WRITABLE (caps2));
658 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))) {
659 /* FIXME: this leaks */
660 caps1->flags |= GST_CAPS_FLAGS_ANY;
661 for (i = caps2->structs->len - 1; i >= 0; i--) {
662 structure = gst_caps_remove_and_get_structure (caps2, i);
663 gst_structure_free (structure);
666 for (i = caps2->structs->len; i; i--) {
667 structure = gst_caps_remove_and_get_structure (caps2, 0);
668 gst_caps_append_structure_unchecked (caps1, structure);
671 gst_caps_unref (caps2); /* guaranteed to free it */
676 * @caps1: the #GstCaps that will take the new entries
677 * @caps2: (transfer full): the #GstCaps to merge in
679 * Appends the structures contained in @caps2 to @caps1 if they are not yet
680 * expressed by @caps1. The structures in @caps2 are not copied -- they are
681 * transferred to @caps1, and then @caps2 is freed.
682 * If either caps is ANY, the resulting caps will be ANY.
687 gst_caps_merge (GstCaps * caps1, GstCaps * caps2)
689 GstStructure *structure;
692 g_return_if_fail (GST_IS_CAPS (caps1));
693 g_return_if_fail (GST_IS_CAPS (caps2));
694 g_return_if_fail (IS_WRITABLE (caps1));
695 g_return_if_fail (IS_WRITABLE (caps2));
700 if (G_UNLIKELY (CAPS_IS_ANY (caps1))) {
701 for (i = caps2->structs->len - 1; i >= 0; i--) {
702 structure = gst_caps_remove_and_get_structure (caps2, i);
703 gst_structure_free (structure);
705 } else if (G_UNLIKELY (CAPS_IS_ANY (caps2))) {
706 caps1->flags |= GST_CAPS_FLAGS_ANY;
707 for (i = caps1->structs->len - 1; i >= 0; i--) {
708 structure = gst_caps_remove_and_get_structure (caps1, i);
709 gst_structure_free (structure);
712 for (i = caps2->structs->len; i; i--) {
713 structure = gst_caps_remove_and_get_structure (caps2, 0);
714 gst_caps_merge_structure (caps1, structure);
717 GstCaps *com = gst_caps_intersect (caps1, caps2);
718 GstCaps *add = gst_caps_subtract (caps2, com);
720 GST_DEBUG ("common : %d", gst_caps_get_size (com));
721 GST_DEBUG ("adding : %d", gst_caps_get_size (add));
722 gst_caps_append (caps1, add);
723 gst_caps_unref (com);
726 gst_caps_unref (caps2); /* guaranteed to free it */
730 * gst_caps_append_structure:
731 * @caps: the #GstCaps that will be appended to
732 * @structure: (transfer full): the #GstStructure to append
734 * Appends @structure to @caps. The structure is not copied; @caps
735 * becomes the owner of @structure.
738 gst_caps_append_structure (GstCaps * caps, GstStructure * structure)
740 g_return_if_fail (GST_IS_CAPS (caps));
741 g_return_if_fail (IS_WRITABLE (caps));
743 if (G_LIKELY (structure)) {
744 g_return_if_fail (structure->parent_refcount == NULL);
747 STRUCTURE_POISON (structure);
750 gst_caps_append_structure_unchecked (caps, structure);
755 * gst_caps_remove_structure:
756 * @caps: the #GstCaps to remove from
757 * @idx: Index of the structure to remove
759 * removes the stucture with the given index from the list of structures
760 * contained in @caps.
763 gst_caps_remove_structure (GstCaps * caps, guint idx)
765 GstStructure *structure;
767 g_return_if_fail (caps != NULL);
768 g_return_if_fail (idx <= gst_caps_get_size (caps));
769 g_return_if_fail (IS_WRITABLE (caps));
771 structure = gst_caps_remove_and_get_structure (caps, idx);
772 gst_structure_free (structure);
776 * gst_caps_merge_structure:
777 * @caps: the #GstCaps that will the the new structure
778 * @structure: (transfer full): the #GstStructure to merge
780 * Appends @structure to @caps if its not already expressed by @caps. The
781 * structure is not copied; @caps becomes the owner of @structure.
784 gst_caps_merge_structure (GstCaps * caps, GstStructure * structure)
786 g_return_if_fail (GST_IS_CAPS (caps));
787 g_return_if_fail (IS_WRITABLE (caps));
789 if (G_LIKELY (structure)) {
790 GstStructure *structure1;
792 gboolean unique = TRUE;
794 g_return_if_fail (structure->parent_refcount == NULL);
797 STRUCTURE_POISON (structure);
800 /* check each structure */
801 for (i = caps->structs->len - 1; i >= 0; i--) {
802 structure1 = gst_caps_get_structure_unchecked (caps, i);
803 /* if structure is a subset of structure1, then skip it */
804 if (gst_caps_structure_is_subset (structure1, structure)) {
810 gst_caps_append_structure_unchecked (caps, structure);
812 gst_structure_free (structure);
821 * Gets the number of structures contained in @caps.
823 * Returns: the number of structures that @caps contains
826 gst_caps_get_size (const GstCaps * caps)
828 g_return_val_if_fail (GST_IS_CAPS (caps), 0);
830 return caps->structs->len;
834 * gst_caps_get_structure:
836 * @index: the index of the structure
838 * Finds the structure in @caps that has the index @index, and
841 * WARNING: This function takes a const GstCaps *, but returns a
842 * non-const GstStructure *. This is for programming convenience --
843 * the caller should be aware that structures inside a constant
844 * #GstCaps should not be modified. However, if you know the caps
845 * are writable, either because you have just copied them or made
846 * them writable with gst_caps_make_writable(), you may modify the
847 * structure returned in the usual way, e.g. with functions like
848 * gst_structure_set().
850 * You do not need to free or unref the structure returned, it
851 * belongs to the #GstCaps.
853 * Returns: (transfer none): a pointer to the #GstStructure corresponding
857 gst_caps_get_structure (const GstCaps * caps, guint index)
859 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
860 g_return_val_if_fail (index < caps->structs->len, NULL);
862 return gst_caps_get_structure_unchecked (caps, index);
867 * @caps: the #GstCaps to copy
868 * @nth: the nth structure to copy
870 * Creates a new #GstCaps and appends a copy of the nth structure
871 * contained in @caps.
873 * Returns: (transfer full): the new #GstCaps
876 gst_caps_copy_nth (const GstCaps * caps, guint nth)
879 GstStructure *structure;
881 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
883 newcaps = gst_caps_new_empty ();
884 newcaps->flags = caps->flags;
886 if (G_LIKELY (caps->structs->len > nth)) {
887 structure = gst_caps_get_structure_unchecked (caps, nth);
888 gst_caps_append_structure_unchecked (newcaps,
889 gst_structure_copy (structure));
897 * @caps: the #GstCaps to truncate
899 * Destructively discard all but the first structure from @caps. Useful when
900 * fixating. @caps must be writable.
903 gst_caps_truncate (GstCaps * caps)
907 g_return_if_fail (GST_IS_CAPS (caps));
908 g_return_if_fail (IS_WRITABLE (caps));
910 i = caps->structs->len - 1;
913 gst_caps_remove_structure (caps, i--);
917 * gst_caps_set_value:
918 * @caps: a writable caps
919 * @field: name of the field to set
920 * @value: value to set the field to
922 * Sets the given @field on all structures of @caps to the given @value.
923 * This is a convenience function for calling gst_structure_set_value() on
924 * all structures of @caps.
929 gst_caps_set_value (GstCaps * caps, const char *field, const GValue * value)
933 g_return_if_fail (GST_IS_CAPS (caps));
934 g_return_if_fail (IS_WRITABLE (caps));
935 g_return_if_fail (field != NULL);
936 g_return_if_fail (G_IS_VALUE (value));
938 len = caps->structs->len;
939 for (i = 0; i < len; i++) {
940 GstStructure *structure = gst_caps_get_structure_unchecked (caps, i);
941 gst_structure_set_value (structure, field, value);
946 * gst_caps_set_simple_valist:
947 * @caps: the #GstCaps to set
948 * @field: first field to set
949 * @varargs: additional parameters
951 * Sets fields in a #GstCaps. The arguments must be passed in the same
952 * manner as gst_structure_set(), and be NULL-terminated.
953 * <note>Prior to GStreamer version 0.10.26, this function failed when
954 * @caps was not simple. If your code needs to work with those versions
955 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
956 * is %TRUE for @caps.</note>
959 gst_caps_set_simple_valist (GstCaps * caps, const char *field, va_list varargs)
961 GValue value = { 0, };
963 g_return_if_fail (GST_IS_CAPS (caps));
964 g_return_if_fail (IS_WRITABLE (caps));
970 type = va_arg (varargs, GType);
972 if (G_UNLIKELY (type == G_TYPE_DATE)) {
973 g_warning ("Don't use G_TYPE_DATE, use GST_TYPE_DATE instead\n");
974 type = GST_TYPE_DATE;
976 #if GLIB_CHECK_VERSION(2,23,3)
977 G_VALUE_COLLECT_INIT (&value, type, varargs, 0, &err);
979 g_value_init (&value, type);
980 G_VALUE_COLLECT (&value, varargs, 0, &err);
982 if (G_UNLIKELY (err)) {
983 g_critical ("%s", err);
987 gst_caps_set_value (caps, field, &value);
989 g_value_unset (&value);
991 field = va_arg (varargs, const gchar *);
996 * gst_caps_set_simple:
997 * @caps: the #GstCaps to set
998 * @field: first field to set
999 * @...: additional parameters
1001 * Sets fields in a #GstCaps. The arguments must be passed in the same
1002 * manner as gst_structure_set(), and be NULL-terminated.
1003 * <note>Prior to GStreamer version 0.10.26, this function failed when
1004 * @caps was not simple. If your code needs to work with those versions
1005 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
1006 * is %TRUE for @caps.</note>
1009 gst_caps_set_simple (GstCaps * caps, const char *field, ...)
1013 g_return_if_fail (GST_IS_CAPS (caps));
1014 g_return_if_fail (IS_WRITABLE (caps));
1016 va_start (var_args, field);
1017 gst_caps_set_simple_valist (caps, field, var_args);
1025 * @caps: the #GstCaps to test
1027 * Determines if @caps represents any media format.
1029 * Returns: TRUE if @caps represents any format.
1032 gst_caps_is_any (const GstCaps * caps)
1034 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1036 return (CAPS_IS_ANY (caps));
1040 * gst_caps_is_empty:
1041 * @caps: the #GstCaps to test
1043 * Determines if @caps represents no media formats.
1045 * Returns: TRUE if @caps represents no formats.
1048 gst_caps_is_empty (const GstCaps * caps)
1050 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1052 if (CAPS_IS_ANY (caps))
1055 return CAPS_IS_EMPTY_SIMPLE (caps);
1059 gst_caps_is_fixed_foreach (GQuark field_id, const GValue * value,
1062 return gst_value_is_fixed (value);
1066 * gst_caps_is_fixed:
1067 * @caps: the #GstCaps to test
1069 * Fixed #GstCaps describe exactly one format, that is, they have exactly
1070 * one structure, and each field in the structure describes a fixed type.
1071 * Examples of non-fixed types are GST_TYPE_INT_RANGE and GST_TYPE_LIST.
1073 * Returns: TRUE if @caps is fixed
1076 gst_caps_is_fixed (const GstCaps * caps)
1078 GstStructure *structure;
1080 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1082 if (caps->structs->len != 1)
1085 structure = gst_caps_get_structure_unchecked (caps, 0);
1087 return gst_structure_foreach (structure, gst_caps_is_fixed_foreach, NULL);
1091 * gst_caps_is_equal_fixed:
1092 * @caps1: the #GstCaps to test
1093 * @caps2: the #GstCaps to test
1095 * Tests if two #GstCaps are equal. This function only works on fixed
1098 * Returns: TRUE if the arguments represent the same format
1101 gst_caps_is_equal_fixed (const GstCaps * caps1, const GstCaps * caps2)
1103 GstStructure *struct1, *struct2;
1105 g_return_val_if_fail (gst_caps_is_fixed (caps1), FALSE);
1106 g_return_val_if_fail (gst_caps_is_fixed (caps2), FALSE);
1108 struct1 = gst_caps_get_structure_unchecked (caps1, 0);
1109 struct2 = gst_caps_get_structure_unchecked (caps2, 0);
1111 if (struct1->name != struct2->name) {
1114 if (struct1->fields->len != struct2->fields->len) {
1118 return gst_structure_foreach (struct1, gst_structure_is_equal_foreach,
1123 * gst_caps_is_always_compatible:
1124 * @caps1: the #GstCaps to test
1125 * @caps2: the #GstCaps to test
1127 * A given #GstCaps structure is always compatible with another if
1128 * every media format that is in the first is also contained in the
1129 * second. That is, @caps1 is a subset of @caps2.
1131 * Returns: TRUE if @caps1 is a subset of @caps2.
1134 gst_caps_is_always_compatible (const GstCaps * caps1, const GstCaps * caps2)
1136 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1137 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1139 return gst_caps_is_subset (caps1, caps2);
1143 * gst_caps_is_subset:
1144 * @subset: a #GstCaps
1145 * @superset: a potentially greater #GstCaps
1147 * Checks if all caps represented by @subset are also represented by @superset.
1148 * <note>This function does not work reliably if optional properties for caps
1149 * are included on one caps and omitted on the other.</note>
1151 * Returns: %TRUE if @subset is a subset of @superset
1154 gst_caps_is_subset (const GstCaps * subset, const GstCaps * superset)
1159 g_return_val_if_fail (subset != NULL, FALSE);
1160 g_return_val_if_fail (superset != NULL, FALSE);
1162 if (CAPS_IS_EMPTY (subset) || CAPS_IS_ANY (superset))
1164 if (CAPS_IS_ANY (subset) || CAPS_IS_EMPTY (superset))
1167 caps = gst_caps_subtract (subset, superset);
1168 ret = CAPS_IS_EMPTY_SIMPLE (caps);
1169 gst_caps_unref (caps);
1174 * gst_caps_is_equal:
1175 * @caps1: a #GstCaps
1176 * @caps2: another #GstCaps
1178 * Checks if the given caps represent the same set of caps.
1179 * <note>This function does not work reliably if optional properties for caps
1180 * are included on one caps and omitted on the other.</note>
1182 * This function deals correctly with passing NULL for any of the caps.
1184 * Returns: TRUE if both caps are equal.
1187 gst_caps_is_equal (const GstCaps * caps1, const GstCaps * caps2)
1189 /* FIXME 0.11: NULL pointers are no valid Caps but indicate an error
1190 * So there should be an assertion that caps1 and caps2 != NULL */
1192 /* NULL <-> NULL is allowed here */
1193 if (G_UNLIKELY (caps1 == caps2))
1196 /* one of them NULL => they are different (can't be both NULL because
1197 * we checked that above) */
1198 if (G_UNLIKELY (caps1 == NULL || caps2 == NULL))
1201 if (G_UNLIKELY (gst_caps_is_fixed (caps1) && gst_caps_is_fixed (caps2)))
1202 return gst_caps_is_equal_fixed (caps1, caps2);
1204 return gst_caps_is_subset (caps1, caps2) && gst_caps_is_subset (caps2, caps1);
1207 /* intersect operation */
1212 const GstStructure *intersect;
1217 gst_caps_structure_intersect_field1 (GQuark id, const GValue * val1,
1220 IntersectData *idata = (IntersectData *) data;
1221 const GValue *val2 = gst_structure_id_get_value (idata->intersect, id);
1223 if (G_UNLIKELY (val2 == NULL)) {
1224 gst_structure_id_set_value (idata->dest, id, val1);
1226 GValue dest_value = { 0 };
1227 if (gst_value_intersect (&dest_value, val1, val2)) {
1228 gst_structure_id_set_value (idata->dest, id, &dest_value);
1229 g_value_unset (&dest_value);
1238 gst_caps_structure_intersect_field2 (GQuark id, const GValue * val1,
1241 IntersectData *idata = (IntersectData *) data;
1242 const GValue *val2 = gst_structure_id_get_value (idata->intersect, id);
1244 if (G_UNLIKELY (val2 == NULL)) {
1245 gst_structure_id_set_value (idata->dest, id, val1);
1250 static GstStructure *
1251 gst_caps_structure_intersect (const GstStructure * struct1,
1252 const GstStructure * struct2)
1256 g_assert (struct1 != NULL);
1257 g_assert (struct2 != NULL);
1259 if (G_UNLIKELY (struct1->name != struct2->name))
1262 /* copy fields from struct1 which we have not in struct2 to target
1263 * intersect if we have the field in both */
1264 data.dest = gst_structure_id_empty_new (struct1->name);
1265 data.intersect = struct2;
1266 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct1,
1267 gst_caps_structure_intersect_field1, &data)))
1270 /* copy fields from struct2 which we have not in struct1 to target */
1271 data.intersect = struct1;
1272 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct2,
1273 gst_caps_structure_intersect_field2, &data)))
1279 gst_structure_free (data.dest);
1284 gst_caps_structure_can_intersect_field (GQuark id, const GValue * val1,
1287 GstStructure *other = (GstStructure *) data;
1288 const GValue *val2 = gst_structure_id_get_value (other, id);
1290 if (G_LIKELY (val2)) {
1291 if (!gst_value_can_intersect (val1, val2)) {
1294 gint eq = gst_value_compare (val1, val2);
1296 if (eq == GST_VALUE_UNORDERED) {
1297 /* we need to try interseting */
1298 GValue dest_value = { 0 };
1299 if (gst_value_intersect (&dest_value, val1, val2)) {
1300 g_value_unset (&dest_value);
1304 } else if (eq != GST_VALUE_EQUAL) {
1313 gst_caps_structure_can_intersect (const GstStructure * struct1,
1314 const GstStructure * struct2)
1316 g_assert (struct1 != NULL);
1317 g_assert (struct2 != NULL);
1319 if (G_UNLIKELY (struct1->name != struct2->name))
1322 /* tries to intersect if we have the field in both */
1323 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct1,
1324 gst_caps_structure_can_intersect_field, (gpointer) struct2)))
1331 * gst_caps_can_intersect:
1332 * @caps1: a #GstCaps to intersect
1333 * @caps2: a #GstCaps to intersect
1335 * Tries intersecting @caps1 and @caps2 and reports whether the result would not
1338 * Returns: %TRUE if intersection would be not empty
1343 gst_caps_can_intersect (const GstCaps * caps1, const GstCaps * caps2)
1345 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1346 guint j, k, len1, len2;
1347 GstStructure *struct1;
1348 GstStructure *struct2;
1350 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1351 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1353 /* caps are exactly the same pointers */
1354 if (G_UNLIKELY (caps1 == caps2))
1357 /* empty caps on either side, return empty */
1358 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1361 /* one of the caps is any */
1362 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2)))
1365 /* run zigzag on top line then right line, this preserves the caps order
1366 * much better than a simple loop.
1368 * This algorithm zigzags over the caps structures as demonstrated in
1369 * the folowing matrix:
1372 * +------------- total distance: +-------------
1373 * | 1 2 4 7 0 | 0 1 2 3
1374 * caps2 | 3 5 8 10 1 | 1 2 3 4
1375 * | 6 9 11 12 2 | 2 3 4 5
1377 * First we iterate over the caps1 structures (top line) intersecting
1378 * the structures diagonally down, then we iterate over the caps2
1379 * structures. The result is that the intersections are ordered based on the
1380 * sum of the indexes in the list.
1382 len1 = caps1->structs->len;
1383 len2 = caps2->structs->len;
1384 for (i = 0; i < len1 + len2 - 1; i++) {
1385 /* superset index goes from 0 to sgst_caps_structure_intersectuperset->structs->len-1 */
1386 j = MIN (i, len1 - 1);
1387 /* subset index stays 0 until i reaches superset->structs->len, then it
1388 * counts up from 1 to subset->structs->len - 1 */
1391 /* now run the diagonal line, end condition is the left or bottom
1394 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1395 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1397 if (gst_caps_structure_can_intersect (struct1, struct2)) {
1400 /* move down left */
1402 if (G_UNLIKELY (j == 0))
1403 break; /* so we don't roll back to G_MAXUINT */
1411 * gst_caps_intersect:
1412 * @caps1: a #GstCaps to intersect
1413 * @caps2: a #GstCaps to intersect
1415 * Creates a new #GstCaps that contains all the formats that are common
1416 * to both @caps1 and @caps2.
1418 * Returns: the new #GstCaps
1421 gst_caps_intersect (const GstCaps * caps1, const GstCaps * caps2)
1423 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1424 guint j, k, len1, len2;
1426 GstStructure *struct1;
1427 GstStructure *struct2;
1429 GstStructure *istruct;
1431 g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
1432 g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
1434 /* caps are exactly the same pointers, just copy one caps */
1435 if (G_UNLIKELY (caps1 == caps2))
1436 return gst_caps_copy (caps1);
1438 /* empty caps on either side, return empty */
1439 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1440 return gst_caps_new_empty ();
1442 /* one of the caps is any, just copy the other caps */
1443 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1444 return gst_caps_copy (caps2);
1445 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1446 return gst_caps_copy (caps1);
1448 dest = gst_caps_new_empty ();
1450 /* run zigzag on top line then right line, this preserves the caps order
1451 * much better than a simple loop.
1453 * This algorithm zigzags over the caps structures as demonstrated in
1454 * the folowing matrix:
1462 * First we iterate over the caps1 structures (top line) intersecting
1463 * the structures diagonally down, then we iterate over the caps2
1466 len1 = caps1->structs->len;
1467 len2 = caps2->structs->len;
1468 for (i = 0; i < len1 + len2 - 1; i++) {
1469 /* caps1 index goes from 0 to caps1->structs->len-1 */
1470 j = MIN (i, len1 - 1);
1471 /* caps2 index stays 0 until i reaches caps1->structs->len, then it counts
1472 * up from 1 to caps2->structs->len - 1 */
1475 /* now run the diagonal line, end condition is the left or bottom
1478 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1479 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1481 istruct = gst_caps_structure_intersect (struct1, struct2);
1483 gst_caps_append_structure (dest, istruct);
1484 /* move down left */
1486 if (G_UNLIKELY (j == 0))
1487 break; /* so we don't roll back to G_MAXUINT */
1494 /* subtract operation */
1498 const GstStructure *subtract_from;
1504 gst_caps_structure_subtract_field (GQuark field_id, const GValue * value,
1507 SubtractionEntry *e = user_data;
1508 GValue subtraction = { 0, };
1509 const GValue *other;
1510 GstStructure *structure;
1512 other = gst_structure_id_get_value (e->subtract_from, field_id);
1516 if (!gst_value_subtract (&subtraction, other, value))
1518 if (gst_value_compare (&subtraction, other) == GST_VALUE_EQUAL) {
1519 g_value_unset (&subtraction);
1522 structure = gst_structure_copy (e->subtract_from);
1523 gst_structure_id_set_value (structure, field_id, &subtraction);
1524 g_value_unset (&subtraction);
1525 e->put_into = g_slist_prepend (e->put_into, structure);
1531 gst_caps_structure_subtract (GSList ** into, const GstStructure * minuend,
1532 const GstStructure * subtrahend)
1537 e.subtract_from = minuend;
1540 ret = gst_structure_foreach ((GstStructure *) subtrahend,
1541 gst_caps_structure_subtract_field, &e);
1547 for (walk = e.put_into; walk; walk = g_slist_next (walk)) {
1548 gst_structure_free (walk->data);
1550 g_slist_free (e.put_into);
1556 * gst_caps_subtract:
1557 * @minuend: #GstCaps to substract from
1558 * @subtrahend: #GstCaps to substract
1560 * Subtracts the @subtrahend from the @minuend.
1561 * <note>This function does not work reliably if optional properties for caps
1562 * are included on one caps and omitted on the other.</note>
1564 * Returns: the resulting caps
1567 gst_caps_subtract (const GstCaps * minuend, const GstCaps * subtrahend)
1572 GstCaps *dest = NULL, *src;
1574 g_return_val_if_fail (minuend != NULL, NULL);
1575 g_return_val_if_fail (subtrahend != NULL, NULL);
1577 if (CAPS_IS_EMPTY (minuend) || CAPS_IS_ANY (subtrahend)) {
1578 return gst_caps_new_empty ();
1580 if (CAPS_IS_EMPTY_SIMPLE (subtrahend))
1581 return gst_caps_copy (minuend);
1583 /* FIXME: Do we want this here or above?
1584 The reason we need this is that there is no definition about what
1585 ANY means for specific types, so it's not possible to reduce ANY partially
1586 You can only remove everything or nothing and that is done above.
1587 Note: there's a test that checks this behaviour. */
1588 g_return_val_if_fail (!CAPS_IS_ANY (minuend), NULL);
1589 sublen = subtrahend->structs->len;
1590 g_assert (sublen > 0);
1592 src = gst_caps_copy (minuend);
1593 for (i = 0; i < sublen; i++) {
1596 sub = gst_caps_get_structure_unchecked (subtrahend, i);
1598 gst_caps_unref (src);
1601 dest = gst_caps_new_empty ();
1602 srclen = src->structs->len;
1603 for (j = 0; j < srclen; j++) {
1604 min = gst_caps_get_structure_unchecked (src, j);
1605 if (gst_structure_get_name_id (min) == gst_structure_get_name_id (sub)) {
1608 if (gst_caps_structure_subtract (&list, min, sub)) {
1611 for (walk = list; walk; walk = g_slist_next (walk)) {
1612 gst_caps_append_structure_unchecked (dest,
1613 (GstStructure *) walk->data);
1615 g_slist_free (list);
1617 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1620 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1623 if (CAPS_IS_EMPTY_SIMPLE (dest)) {
1624 gst_caps_unref (src);
1629 gst_caps_unref (src);
1630 gst_caps_do_simplify (dest);
1634 /* union operation */
1637 static GstStructure *
1638 gst_caps_structure_union (const GstStructure * struct1,
1639 const GstStructure * struct2)
1643 const GstStructureField *field1;
1644 const GstStructureField *field2;
1647 /* FIXME this doesn't actually work */
1649 if (struct1->name != struct2->name)
1652 dest = gst_structure_id_empty_new (struct1->name);
1654 for (i = 0; i < struct1->fields->len; i++) {
1655 GValue dest_value = { 0 };
1657 field1 = GST_STRUCTURE_FIELD (struct1, i);
1658 field2 = gst_structure_id_get_field (struct2, field1->name);
1660 if (field2 == NULL) {
1663 if (gst_value_union (&dest_value, &field1->value, &field2->value)) {
1664 gst_structure_set_value (dest, g_quark_to_string (field1->name),
1667 ret = gst_value_compare (&field1->value, &field2->value);
1678 * @caps1: a #GstCaps to union
1679 * @caps2: a #GstCaps to union
1681 * Creates a new #GstCaps that contains all the formats that are in
1682 * either @caps1 and @caps2.
1684 * Returns: the new #GstCaps
1687 gst_caps_union (const GstCaps * caps1, const GstCaps * caps2)
1692 /* NULL pointers are no correct GstCaps */
1693 g_return_val_if_fail (caps1 != NULL, NULL);
1694 g_return_val_if_fail (caps2 != NULL, NULL);
1696 if (CAPS_IS_EMPTY (caps1))
1697 return gst_caps_copy (caps2);
1699 if (CAPS_IS_EMPTY (caps2))
1700 return gst_caps_copy (caps1);
1702 if (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))
1703 return gst_caps_new_any ();
1705 dest1 = gst_caps_copy (caps1);
1706 dest2 = gst_caps_copy (caps2);
1707 gst_caps_append (dest1, dest2);
1709 gst_caps_do_simplify (dest1);
1713 /* normalize/simplify operations */
1715 typedef struct _NormalizeForeach
1718 GstStructure *structure;
1723 gst_caps_normalize_foreach (GQuark field_id, const GValue * value, gpointer ptr)
1725 NormalizeForeach *nf = (NormalizeForeach *) ptr;
1729 if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
1730 guint len = gst_value_list_get_size (value);
1731 for (i = 1; i < len; i++) {
1732 const GValue *v = gst_value_list_get_value (value, i);
1733 GstStructure *structure = gst_structure_copy (nf->structure);
1735 gst_structure_id_set_value (structure, field_id, v);
1736 gst_caps_append_structure_unchecked (nf->caps, structure);
1739 gst_value_init_and_copy (&val, gst_value_list_get_value (value, 0));
1740 gst_structure_id_set_value (nf->structure, field_id, &val);
1741 g_value_unset (&val);
1749 * gst_caps_normalize:
1750 * @caps: a #GstCaps to normalize
1752 * Creates a new #GstCaps that represents the same set of formats as
1753 * @caps, but contains no lists. Each list is expanded into separate
1756 * Returns: the new #GstCaps
1759 gst_caps_normalize (const GstCaps * caps)
1761 NormalizeForeach nf;
1765 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
1767 newcaps = gst_caps_copy (caps);
1770 for (i = 0; i < gst_caps_get_size (newcaps); i++) {
1771 nf.structure = gst_caps_get_structure_unchecked (newcaps, i);
1773 while (!gst_structure_foreach (nf.structure,
1774 gst_caps_normalize_foreach, &nf));
1781 gst_caps_compare_structures (gconstpointer one, gconstpointer two)
1784 const GstStructure *struct1 = *((const GstStructure **) one);
1785 const GstStructure *struct2 = *((const GstStructure **) two);
1787 /* FIXME: this orders alphabetically, but ordering the quarks might be faster
1788 So what's the best way? */
1789 ret = strcmp (gst_structure_get_name (struct1),
1790 gst_structure_get_name (struct2));
1794 return gst_structure_n_fields (struct2) - gst_structure_n_fields (struct1);
1801 GstStructure *compare;
1806 gst_caps_structure_figure_out_union (GQuark field_id, const GValue * value,
1809 UnionField *u = user_data;
1810 const GValue *val = gst_structure_id_get_value (u->compare, field_id);
1814 g_value_unset (&u->value);
1817 if (gst_value_compare (val, value) == GST_VALUE_EQUAL)
1820 g_value_unset (&u->value);
1824 gst_value_union (&u->value, val, value);
1829 gst_caps_structure_simplify (GstStructure ** result,
1830 const GstStructure * simplify, GstStructure * compare)
1833 UnionField field = { 0, {0,}, NULL };
1835 /* try to subtract to get a real subset */
1836 if (gst_caps_structure_subtract (&list, simplify, compare)) {
1837 if (list == NULL) { /* no result */
1840 } else if (list->next == NULL) { /* one result */
1841 *result = list->data;
1842 g_slist_free (list);
1844 } else { /* multiple results */
1845 g_slist_foreach (list, (GFunc) gst_structure_free, NULL);
1846 g_slist_free (list);
1851 /* try to union both structs */
1852 field.compare = compare;
1853 if (gst_structure_foreach ((GstStructure *) simplify,
1854 gst_caps_structure_figure_out_union, &field)) {
1855 gboolean ret = FALSE;
1857 /* now we know all of simplify's fields are the same in compare
1858 * but at most one field: field.name */
1859 if (G_IS_VALUE (&field.value)) {
1860 if (gst_structure_n_fields (simplify) == gst_structure_n_fields (compare)) {
1861 gst_structure_id_set_value (compare, field.name, &field.value);
1865 g_value_unset (&field.value);
1866 } else if (gst_structure_n_fields (simplify) <=
1867 gst_structure_n_fields (compare)) {
1868 /* compare is just more specific, will be optimized away later */
1869 /* FIXME: do this here? */
1870 GST_LOG ("found a case that will be optimized later.");
1872 gchar *one = gst_structure_to_string (simplify);
1873 gchar *two = gst_structure_to_string (compare);
1876 ("caps mismatch: structures %s and %s claim to be possible to unify, but aren't",
1888 gst_caps_switch_structures (GstCaps * caps, GstStructure * old,
1889 GstStructure * new, gint i)
1891 gst_structure_set_parent_refcount (old, NULL);
1892 gst_structure_free (old);
1893 gst_structure_set_parent_refcount (new, &caps->refcount);
1894 g_ptr_array_index (caps->structs, i) = new;
1898 * gst_caps_do_simplify:
1899 * @caps: a #GstCaps to simplify
1901 * Modifies the given @caps inplace into a representation that represents the
1902 * same set of formats, but in a simpler form. Component structures that are
1903 * identical are merged. Component structures that have values that can be
1904 * merged are also merged.
1906 * Returns: TRUE, if the caps could be simplified
1909 gst_caps_do_simplify (GstCaps * caps)
1911 GstStructure *simplify, *compare, *result = NULL;
1913 gboolean changed = FALSE;
1915 g_return_val_if_fail (caps != NULL, FALSE);
1916 g_return_val_if_fail (IS_WRITABLE (caps), FALSE);
1918 if (gst_caps_get_size (caps) < 2)
1921 g_ptr_array_sort (caps->structs, gst_caps_compare_structures);
1923 start = caps->structs->len - 1;
1924 for (i = caps->structs->len - 1; i >= 0; i--) {
1925 simplify = gst_caps_get_structure_unchecked (caps, i);
1926 if (gst_structure_get_name_id (simplify) !=
1927 gst_structure_get_name_id (gst_caps_get_structure_unchecked (caps,
1930 for (j = start; j >= 0; j--) {
1933 compare = gst_caps_get_structure_unchecked (caps, j);
1934 if (gst_structure_get_name_id (simplify) !=
1935 gst_structure_get_name_id (compare)) {
1938 if (gst_caps_structure_simplify (&result, simplify, compare)) {
1940 gst_caps_switch_structures (caps, simplify, result, i);
1943 gst_caps_remove_structure (caps, i);
1955 /* gst_caps_do_simplify (caps); */
1963 * @caps: (inout) (transfer full): a pointer to #GstCaps
1964 * @newcaps: a #GstCaps to replace *caps
1966 * Replaces *caps with @newcaps. Unrefs the #GstCaps in the location
1967 * pointed to by @caps, if applicable, then modifies @caps to point to
1968 * @newcaps. An additional ref on @newcaps is taken.
1970 * This function does not take any locks so you might want to lock
1971 * the object owning @caps pointer.
1974 gst_caps_replace (GstCaps ** caps, GstCaps * newcaps)
1978 g_return_if_fail (caps != NULL);
1982 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p, %p -> %p", caps, oldcaps, newcaps);
1984 if (newcaps != oldcaps) {
1986 gst_caps_ref (newcaps);
1991 gst_caps_unref (oldcaps);
1996 * gst_caps_to_string:
1999 * Converts @caps to a string representation. This string representation
2000 * can be converted back to a #GstCaps by gst_caps_from_string().
2002 * For debugging purposes its easier to do something like this:
2004 * GST_LOG ("caps are %" GST_PTR_FORMAT, caps);
2006 * This prints the caps in human readble form.
2008 * Returns: (transfer full): a newly allocated string representing @caps.
2011 gst_caps_to_string (const GstCaps * caps)
2013 guint i, slen, clen;
2016 /* NOTE: This function is potentially called by the debug system,
2017 * so any calls to gst_log() (and GST_DEBUG(), GST_LOG(), etc.)
2018 * should be careful to avoid recursion. This includes any functions
2019 * called by gst_caps_to_string. In particular, calls should
2020 * not use the GST_PTR_FORMAT extension. */
2023 return g_strdup ("NULL");
2025 if (CAPS_IS_ANY (caps)) {
2026 return g_strdup ("ANY");
2028 if (CAPS_IS_EMPTY_SIMPLE (caps)) {
2029 return g_strdup ("EMPTY");
2032 /* estimate a rough string length to avoid unnecessary reallocs in GString */
2034 clen = caps->structs->len;
2035 for (i = 0; i < clen; i++) {
2037 STRUCTURE_ESTIMATED_STRING_LEN (gst_caps_get_structure_unchecked (caps,
2041 s = g_string_sized_new (slen);
2042 for (i = 0; i < clen; i++) {
2043 GstStructure *structure;
2046 /* ';' is now added by gst_structure_to_string */
2047 g_string_append_c (s, ' ');
2050 structure = gst_caps_get_structure_unchecked (caps, i);
2051 priv_gst_structure_append_to_gstring (structure, s);
2053 if (s->len && s->str[s->len - 1] == ';') {
2054 /* remove latest ';' */
2055 s->str[--s->len] = '\0';
2057 return g_string_free (s, FALSE);
2061 gst_caps_from_string_inplace (GstCaps * caps, const gchar * string)
2063 GstStructure *structure;
2066 if (strcmp ("ANY", string) == 0) {
2067 caps->flags = GST_CAPS_FLAGS_ANY;
2070 if (strcmp ("EMPTY", string) == 0) {
2074 structure = gst_structure_from_string (string, &s);
2075 if (structure == NULL) {
2078 gst_caps_append_structure_unchecked (caps, structure);
2082 while (g_ascii_isspace (*s))
2087 structure = gst_structure_from_string (s, &s);
2088 if (structure == NULL) {
2091 gst_caps_append_structure_unchecked (caps, structure);
2099 * gst_caps_from_string:
2100 * @string: a string to convert to #GstCaps
2102 * Converts @caps from a string representation.
2104 * Returns: (transfer full): a newly allocated #GstCaps
2107 gst_caps_from_string (const gchar * string)
2111 g_return_val_if_fail (string, FALSE);
2113 caps = gst_caps_new_empty ();
2114 if (gst_caps_from_string_inplace (caps, string)) {
2117 gst_caps_unref (caps);
2123 gst_caps_transform_to_string (const GValue * src_value, GValue * dest_value)
2125 g_return_if_fail (G_IS_VALUE (src_value));
2126 g_return_if_fail (G_IS_VALUE (dest_value));
2127 g_return_if_fail (G_VALUE_HOLDS (src_value, GST_TYPE_CAPS));
2128 g_return_if_fail (G_VALUE_HOLDS (dest_value, G_TYPE_STRING)
2129 || G_VALUE_HOLDS (dest_value, G_TYPE_POINTER));
2131 dest_value->data[0].v_pointer =
2132 gst_caps_to_string (src_value->data[0].v_pointer);
2136 gst_caps_copy_conditional (GstCaps * src)
2139 return gst_caps_ref (src);