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",
47 * "format", G_TYPE_STRING, "I420"),
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
79 #define GST_CAPS_ARRAY(c) ((GPtrArray *)((c)->priv))
81 #define GST_CAPS_LEN(c) (GST_CAPS_ARRAY(c)->len)
83 #define IS_WRITABLE(caps) \
84 (GST_CAPS_REFCOUNT_VALUE (caps) == 1)
86 /* same as gst_caps_is_any () */
87 #define CAPS_IS_ANY(caps) \
88 (GST_CAPS_FLAGS(caps) & GST_CAPS_FLAGS_ANY)
90 /* same as gst_caps_is_empty () */
91 #define CAPS_IS_EMPTY(caps) \
92 (!CAPS_IS_ANY(caps) && CAPS_IS_EMPTY_SIMPLE(caps))
94 #define CAPS_IS_EMPTY_SIMPLE(caps) \
95 ((GST_CAPS_ARRAY (caps) == NULL) || (GST_CAPS_LEN (caps) == 0))
97 /* quick way to get a caps structure at an index without doing a type or array
99 #define gst_caps_get_structure_unchecked(caps, index) \
100 ((GstStructure *)g_ptr_array_index (GST_CAPS_ARRAY (caps), (index)))
101 /* quick way to append a structure without checking the args */
102 #define gst_caps_append_structure_unchecked(caps, structure) G_STMT_START{\
103 GstStructure *__s=structure; \
104 if (gst_structure_set_parent_refcount (__s, &GST_MINI_OBJECT_REFCOUNT(caps))) \
105 g_ptr_array_add (GST_CAPS_ARRAY (caps), __s); \
108 /* lock to protect multiple invocations of static caps to caps conversion */
109 G_LOCK_DEFINE_STATIC (static_caps_lock);
111 static void gst_caps_transform_to_string (const GValue * src_value,
112 GValue * dest_value);
113 static gboolean gst_caps_from_string_inplace (GstCaps * caps,
114 const gchar * string);
116 GType _gst_caps_type = 0;
118 GST_DEFINE_MINI_OBJECT_TYPE (GstCaps, gst_caps);
121 _priv_gst_caps_initialize (void)
123 _gst_caps_type = gst_caps_get_type ();
125 g_value_register_transform_func (_gst_caps_type,
126 G_TYPE_STRING, gst_caps_transform_to_string);
130 _gst_caps_copy (const GstCaps * caps)
133 GstStructure *structure;
136 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
138 newcaps = gst_caps_new_empty ();
139 GST_CAPS_FLAGS (newcaps) = GST_CAPS_FLAGS (caps);
140 n = GST_CAPS_LEN (caps);
142 for (i = 0; i < n; i++) {
143 structure = gst_caps_get_structure_unchecked (caps, i);
144 gst_caps_append_structure (newcaps, gst_structure_copy (structure));
150 /* creation/deletion */
152 _gst_caps_free (GstCaps * caps)
154 GstStructure *structure;
157 /* The refcount must be 0, but since we're only called by gst_caps_unref,
158 * don't bother testing. */
159 len = GST_CAPS_LEN (caps);
160 /* This can be used to get statistics about caps sizes */
161 /*GST_CAT_INFO (GST_CAT_CAPS, "caps size: %d", len); */
162 for (i = 0; i < len; i++) {
163 structure = (GstStructure *) gst_caps_get_structure_unchecked (caps, i);
164 gst_structure_set_parent_refcount (structure, NULL);
165 gst_structure_free (structure);
167 g_ptr_array_free (GST_CAPS_ARRAY (caps), TRUE);
169 #ifdef DEBUG_REFCOUNT
170 GST_CAT_LOG (GST_CAT_CAPS, "freeing caps %p", caps);
172 g_slice_free1 (GST_MINI_OBJECT_SIZE (caps), caps);
176 gst_caps_init (GstCaps * caps, gsize size)
178 gst_mini_object_init (GST_MINI_OBJECT_CAST (caps), _gst_caps_type, size);
180 caps->mini_object.copy = (GstMiniObjectCopyFunction) _gst_caps_copy;
181 caps->mini_object.dispose = NULL;
182 caps->mini_object.free = (GstMiniObjectFreeFunction) _gst_caps_free;
184 /* the 32 has been determined by logging caps sizes in _gst_caps_free
185 * but g_ptr_array uses 16 anyway if it expands once, so this does not help
187 * GST_CAPS_ARRAY (caps) = g_ptr_array_sized_new (32);
189 caps->priv = g_ptr_array_new ();
193 * gst_caps_new_empty:
195 * Creates a new #GstCaps that is empty. That is, the returned
196 * #GstCaps contains no media formats.
197 * Caller is responsible for unreffing the returned caps.
199 * Returns: (transfer full): the new #GstCaps
202 gst_caps_new_empty (void)
206 caps = g_slice_new (GstCaps);
208 gst_caps_init (caps, sizeof (GstCaps));
210 #ifdef DEBUG_REFCOUNT
211 GST_CAT_TRACE (GST_CAT_CAPS, "created caps %p", caps);
220 * Creates a new #GstCaps that indicates that it is compatible with
223 * Returns: (transfer full): the new #GstCaps
226 gst_caps_new_any (void)
228 GstCaps *caps = gst_caps_new_empty ();
230 GST_CAPS_FLAG_SET (caps, GST_CAPS_FLAGS_ANY);
236 * gst_caps_new_empty_simple:
237 * @media_type: the media type of the structure
239 * Creates a new #GstCaps that contains one #GstStructure with name
241 * Caller is responsible for unreffing the returned caps.
243 * Returns: (transfer full): the new #GstCaps
246 gst_caps_new_empty_simple (const char *media_type)
249 GstStructure *structure;
251 caps = gst_caps_new_empty ();
252 structure = gst_structure_empty_new (media_type);
254 gst_caps_append_structure_unchecked (caps, structure);
260 * gst_caps_new_simple:
261 * @media_type: the media type of the structure
262 * @fieldname: first field to set
263 * @...: additional arguments
265 * Creates a new #GstCaps that contains one #GstStructure. The
266 * structure is defined by the arguments, which have the same format
267 * as gst_structure_new().
268 * Caller is responsible for unreffing the returned caps.
270 * Returns: (transfer full): the new #GstCaps
273 gst_caps_new_simple (const char *media_type, const char *fieldname, ...)
276 GstStructure *structure;
279 caps = gst_caps_new_empty ();
281 va_start (var_args, fieldname);
282 structure = gst_structure_new_valist (media_type, fieldname, var_args);
286 gst_caps_append_structure_unchecked (caps, structure);
288 gst_caps_replace (&caps, NULL);
295 * @struct1: the first structure to add
296 * @...: additional structures to add
298 * Creates a new #GstCaps and adds all the structures listed as
299 * arguments. The list must be NULL-terminated. The structures
300 * are not copied; the returned #GstCaps owns the structures.
302 * Returns: (transfer full): the new #GstCaps
305 gst_caps_new_full (GstStructure * struct1, ...)
310 va_start (var_args, struct1);
311 caps = gst_caps_new_full_valist (struct1, var_args);
318 * gst_caps_new_full_valist:
319 * @structure: the first structure to add
320 * @var_args: additional structures to add
322 * Creates a new #GstCaps and adds all the structures listed as
323 * arguments. The list must be NULL-terminated. The structures
324 * are not copied; the returned #GstCaps owns the structures.
326 * Returns: (transfer full): the new #GstCaps
329 gst_caps_new_full_valist (GstStructure * structure, va_list var_args)
333 caps = gst_caps_new_empty ();
336 gst_caps_append_structure_unchecked (caps, structure);
337 structure = va_arg (var_args, GstStructure *);
344 gst_static_caps_get_type (void)
346 static GType staticcaps_type = 0;
348 if (G_UNLIKELY (staticcaps_type == 0)) {
349 staticcaps_type = g_pointer_type_register_static ("GstStaticCaps");
351 return staticcaps_type;
356 * gst_static_caps_get:
357 * @static_caps: the #GstStaticCaps to convert
359 * Converts a #GstStaticCaps to a #GstCaps.
361 * Returns: (transfer full): a pointer to the #GstCaps. Unref after usage.
362 * Since the core holds an additional ref to the returned caps,
363 * use gst_caps_make_writable() on the returned caps to modify it.
366 gst_static_caps_get (GstStaticCaps * static_caps)
370 g_return_val_if_fail (static_caps != NULL, NULL);
372 caps = (GstCaps *) static_caps;
374 /* refcount is 0 when we need to convert */
375 if (G_UNLIKELY (GST_CAPS_REFCOUNT_VALUE (caps) == 0)) {
379 G_LOCK (static_caps_lock);
380 /* check if other thread already updated */
381 if (G_UNLIKELY (GST_CAPS_REFCOUNT_VALUE (caps) > 0))
384 string = static_caps->string;
386 if (G_UNLIKELY (string == NULL))
389 GST_CAT_TRACE (GST_CAT_CAPS, "creating %p", static_caps);
391 /* we construct the caps on the stack, then copy over the struct into our
392 * real caps, refcount last. We do this because we must leave the refcount
393 * of the result caps to 0 so that other threads don't run away with the
394 * caps while we are constructing it. */
395 gst_caps_init (&temp, sizeof (GstCaps));
397 /* convert to string */
398 if (G_UNLIKELY (!gst_caps_from_string_inplace (&temp, string)))
399 g_critical ("Could not convert static caps \"%s\"", string);
401 GST_MINI_OBJECT_REFCOUNT (&temp) = 0;
402 memcpy (caps, &temp, sizeof (GstCaps));
405 GST_CAT_TRACE (GST_CAT_CAPS, "created %p", static_caps);
407 G_UNLOCK (static_caps_lock);
409 /* ref the caps, makes it not writable */
417 G_UNLOCK (static_caps_lock);
418 g_warning ("static caps %p string is NULL", static_caps);
424 * gst_static_caps_cleanup:
425 * @static_caps: the #GstStaticCaps to convert
427 * Clean up the caps contained in @static_caps when the refcount is 0.
430 gst_static_caps_cleanup (GstStaticCaps * static_caps)
432 GstCaps *caps = (GstCaps *) static_caps;
434 /* FIXME: this is not threadsafe */
435 if (GST_CAPS_REFCOUNT_VALUE (caps) == 1) {
436 GstStructure *structure;
439 clen = GST_CAPS_LEN (caps);
441 for (i = 0; i < clen; i++) {
442 structure = (GstStructure *) gst_caps_get_structure (caps, i);
443 gst_structure_set_parent_refcount (structure, NULL);
444 gst_structure_free (structure);
446 g_ptr_array_free (GST_CAPS_ARRAY (caps), TRUE);
447 GST_CAPS_REFCOUNT (caps) = 0;
453 static GstStructure *
454 gst_caps_remove_and_get_structure (GstCaps * caps, guint idx)
456 /* don't use index_fast, gst_caps_do_simplify relies on the order */
457 GstStructure *s = g_ptr_array_remove_index (GST_CAPS_ARRAY (caps), idx);
459 gst_structure_set_parent_refcount (s, NULL);
464 * gst_caps_steal_structure:
465 * @caps: the #GstCaps to retrieve from
466 * @index: Index of the structure to retrieve
468 * Retrieves the stucture with the given index from the list of structures
469 * contained in @caps. The caller becomes the owner of the returned structure.
471 * Returns: (transfer full): a pointer to the #GstStructure corresponding
477 gst_caps_steal_structure (GstCaps * caps, guint index)
479 g_return_val_if_fail (caps != NULL, NULL);
480 g_return_val_if_fail (IS_WRITABLE (caps), NULL);
482 if (G_UNLIKELY (index >= GST_CAPS_LEN (caps)))
485 return gst_caps_remove_and_get_structure (caps, index);
490 * @caps1: the #GstCaps that will be appended to
491 * @caps2: (transfer full): the #GstCaps to append
493 * Appends the structures contained in @caps2 to @caps1. The structures in
494 * @caps2 are not copied -- they are transferred to @caps1, and then @caps2 is
495 * freed. If either caps is ANY, the resulting caps will be ANY.
498 gst_caps_append (GstCaps * caps1, GstCaps * caps2)
500 GstStructure *structure;
503 g_return_if_fail (GST_IS_CAPS (caps1));
504 g_return_if_fail (GST_IS_CAPS (caps2));
505 g_return_if_fail (IS_WRITABLE (caps1));
507 caps2 = gst_caps_make_writable (caps2);
509 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))) {
510 /* FIXME: this leaks */
511 GST_CAPS_FLAGS (caps1) |= GST_CAPS_FLAGS_ANY;
512 for (i = GST_CAPS_LEN (caps2) - 1; i >= 0; i--) {
513 structure = gst_caps_remove_and_get_structure (caps2, i);
514 gst_structure_free (structure);
517 for (i = GST_CAPS_LEN (caps2); i; i--) {
518 structure = gst_caps_remove_and_get_structure (caps2, 0);
519 gst_caps_append_structure_unchecked (caps1, structure);
522 gst_caps_unref (caps2); /* guaranteed to free it */
527 * @caps1: the #GstCaps that will take the new entries
528 * @caps2: (transfer full): the #GstCaps to merge in
530 * Appends the structures contained in @caps2 to @caps1 if they are not yet
531 * expressed by @caps1. The structures in @caps2 are not copied -- they are
532 * transferred to @caps1, and then @caps2 is freed.
533 * If either caps is ANY, the resulting caps will be ANY.
538 gst_caps_merge (GstCaps * caps1, GstCaps * caps2)
540 GstStructure *structure;
543 g_return_if_fail (GST_IS_CAPS (caps1));
544 g_return_if_fail (GST_IS_CAPS (caps2));
545 g_return_if_fail (IS_WRITABLE (caps1));
547 caps2 = gst_caps_make_writable (caps2);
549 if (G_UNLIKELY (CAPS_IS_ANY (caps1))) {
550 for (i = GST_CAPS_LEN (caps2) - 1; i >= 0; i--) {
551 structure = gst_caps_remove_and_get_structure (caps2, i);
552 gst_structure_free (structure);
554 } else if (G_UNLIKELY (CAPS_IS_ANY (caps2))) {
555 GST_CAPS_FLAGS (caps1) |= GST_CAPS_FLAGS_ANY;
556 for (i = GST_CAPS_LEN (caps1) - 1; i >= 0; i--) {
557 structure = gst_caps_remove_and_get_structure (caps1, i);
558 gst_structure_free (structure);
561 for (i = GST_CAPS_LEN (caps2); i; i--) {
562 structure = gst_caps_remove_and_get_structure (caps2, 0);
563 gst_caps_merge_structure (caps1, structure);
566 GstCaps *com = gst_caps_intersect (caps1, caps2);
567 GstCaps *add = gst_caps_subtract (caps2, com);
569 GST_DEBUG ("common : %d", gst_caps_get_size (com));
570 GST_DEBUG ("adding : %d", gst_caps_get_size (add));
571 gst_caps_append (caps1, add);
572 gst_caps_unref (com);
575 gst_caps_unref (caps2); /* guaranteed to free it */
579 * gst_caps_append_structure:
580 * @caps: the #GstCaps that will be appended to
581 * @structure: (transfer full): the #GstStructure to append
583 * Appends @structure to @caps. The structure is not copied; @caps
584 * becomes the owner of @structure.
587 gst_caps_append_structure (GstCaps * caps, GstStructure * structure)
589 g_return_if_fail (GST_IS_CAPS (caps));
590 g_return_if_fail (IS_WRITABLE (caps));
592 if (G_LIKELY (structure)) {
593 gst_caps_append_structure_unchecked (caps, structure);
598 * gst_caps_remove_structure:
599 * @caps: the #GstCaps to remove from
600 * @idx: Index of the structure to remove
602 * removes the stucture with the given index from the list of structures
603 * contained in @caps.
606 gst_caps_remove_structure (GstCaps * caps, guint idx)
608 GstStructure *structure;
610 g_return_if_fail (caps != NULL);
611 g_return_if_fail (idx <= gst_caps_get_size (caps));
612 g_return_if_fail (IS_WRITABLE (caps));
614 structure = gst_caps_remove_and_get_structure (caps, idx);
615 gst_structure_free (structure);
619 * gst_caps_merge_structure:
620 * @caps: the #GstCaps that will the new structure
621 * @structure: (transfer full): the #GstStructure to merge
623 * Appends @structure to @caps if its not already expressed by @caps. The
624 * structure is not copied; @caps becomes the owner of @structure.
627 gst_caps_merge_structure (GstCaps * caps, GstStructure * structure)
629 g_return_if_fail (GST_IS_CAPS (caps));
630 g_return_if_fail (IS_WRITABLE (caps));
632 if (G_LIKELY (structure)) {
633 GstStructure *structure1;
635 gboolean unique = TRUE;
637 /* check each structure */
638 for (i = GST_CAPS_LEN (caps) - 1; i >= 0; i--) {
639 structure1 = gst_caps_get_structure_unchecked (caps, i);
640 /* if structure is a subset of structure1, then skip it */
641 if (gst_structure_is_subset (structure, structure1)) {
647 gst_caps_append_structure_unchecked (caps, structure);
649 gst_structure_free (structure);
658 * Gets the number of structures contained in @caps.
660 * Returns: the number of structures that @caps contains
663 gst_caps_get_size (const GstCaps * caps)
665 g_return_val_if_fail (GST_IS_CAPS (caps), 0);
667 return GST_CAPS_LEN (caps);
671 * gst_caps_get_structure:
673 * @index: the index of the structure
675 * Finds the structure in @caps that has the index @index, and
678 * WARNING: This function takes a const GstCaps *, but returns a
679 * non-const GstStructure *. This is for programming convenience --
680 * the caller should be aware that structures inside a constant
681 * #GstCaps should not be modified. However, if you know the caps
682 * are writable, either because you have just copied them or made
683 * them writable with gst_caps_make_writable(), you may modify the
684 * structure returned in the usual way, e.g. with functions like
685 * gst_structure_set().
687 * You do not need to free or unref the structure returned, it
688 * belongs to the #GstCaps.
690 * Returns: (transfer none): a pointer to the #GstStructure corresponding
694 gst_caps_get_structure (const GstCaps * caps, guint index)
696 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
697 g_return_val_if_fail (index < GST_CAPS_LEN (caps), NULL);
699 return gst_caps_get_structure_unchecked (caps, index);
704 * @caps: the #GstCaps to copy
705 * @nth: the nth structure to copy
707 * Creates a new #GstCaps and appends a copy of the nth structure
708 * contained in @caps.
710 * Returns: (transfer full): the new #GstCaps
713 gst_caps_copy_nth (const GstCaps * caps, guint nth)
716 GstStructure *structure;
718 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
720 newcaps = gst_caps_new_empty ();
721 GST_CAPS_FLAGS (newcaps) = GST_CAPS_FLAGS (caps);
723 if (G_LIKELY (GST_CAPS_LEN (caps) > nth)) {
724 structure = gst_caps_get_structure_unchecked (caps, nth);
725 gst_caps_append_structure_unchecked (newcaps,
726 gst_structure_copy (structure));
734 * @caps: the #GstCaps to truncate
736 * Destructively discard all but the first structure from @caps. Useful when
737 * fixating. @caps must be writable.
740 gst_caps_truncate (GstCaps * caps)
744 g_return_if_fail (GST_IS_CAPS (caps));
745 g_return_if_fail (IS_WRITABLE (caps));
747 i = GST_CAPS_LEN (caps) - 1;
750 gst_caps_remove_structure (caps, i--);
754 * gst_caps_set_value:
755 * @caps: a writable caps
756 * @field: name of the field to set
757 * @value: value to set the field to
759 * Sets the given @field on all structures of @caps to the given @value.
760 * This is a convenience function for calling gst_structure_set_value() on
761 * all structures of @caps.
766 gst_caps_set_value (GstCaps * caps, const char *field, const GValue * value)
770 g_return_if_fail (GST_IS_CAPS (caps));
771 g_return_if_fail (IS_WRITABLE (caps));
772 g_return_if_fail (field != NULL);
773 g_return_if_fail (G_IS_VALUE (value));
775 len = GST_CAPS_LEN (caps);
776 for (i = 0; i < len; i++) {
777 GstStructure *structure = gst_caps_get_structure_unchecked (caps, i);
778 gst_structure_set_value (structure, field, value);
783 * gst_caps_set_simple_valist:
784 * @caps: the #GstCaps to set
785 * @field: first field to set
786 * @varargs: additional parameters
788 * Sets fields in a #GstCaps. The arguments must be passed in the same
789 * manner as gst_structure_set(), and be NULL-terminated.
790 * <note>Prior to GStreamer version 0.10.26, this function failed when
791 * @caps was not simple. If your code needs to work with those versions
792 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
793 * is %TRUE for @caps.</note>
796 gst_caps_set_simple_valist (GstCaps * caps, const char *field, va_list varargs)
798 GValue value = { 0, };
800 g_return_if_fail (GST_IS_CAPS (caps));
801 g_return_if_fail (IS_WRITABLE (caps));
807 type = va_arg (varargs, GType);
809 if (G_UNLIKELY (type == G_TYPE_DATE)) {
810 g_warning ("Don't use G_TYPE_DATE, use GST_TYPE_DATE instead\n");
811 type = GST_TYPE_DATE;
813 G_VALUE_COLLECT_INIT (&value, type, varargs, 0, &err);
814 if (G_UNLIKELY (err)) {
815 g_critical ("%s", err);
819 gst_caps_set_value (caps, field, &value);
821 g_value_unset (&value);
823 field = va_arg (varargs, const gchar *);
828 * gst_caps_set_simple:
829 * @caps: the #GstCaps to set
830 * @field: first field to set
831 * @...: additional parameters
833 * Sets fields in a #GstCaps. The arguments must be passed in the same
834 * manner as gst_structure_set(), and be NULL-terminated.
835 * <note>Prior to GStreamer version 0.10.26, this function failed when
836 * @caps was not simple. If your code needs to work with those versions
837 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
838 * is %TRUE for @caps.</note>
841 gst_caps_set_simple (GstCaps * caps, const char *field, ...)
845 g_return_if_fail (GST_IS_CAPS (caps));
846 g_return_if_fail (IS_WRITABLE (caps));
848 va_start (var_args, field);
849 gst_caps_set_simple_valist (caps, field, var_args);
857 * @caps: the #GstCaps to test
859 * Determines if @caps represents any media format.
861 * Returns: TRUE if @caps represents any format.
864 gst_caps_is_any (const GstCaps * caps)
866 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
868 return (CAPS_IS_ANY (caps));
873 * @caps: the #GstCaps to test
875 * Determines if @caps represents no media formats.
877 * Returns: TRUE if @caps represents no formats.
880 gst_caps_is_empty (const GstCaps * caps)
882 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
884 if (CAPS_IS_ANY (caps))
887 return CAPS_IS_EMPTY_SIMPLE (caps);
891 gst_caps_is_fixed_foreach (GQuark field_id, const GValue * value,
894 return gst_value_is_fixed (value);
899 * @caps: the #GstCaps to test
901 * Fixed #GstCaps describe exactly one format, that is, they have exactly
902 * one structure, and each field in the structure describes a fixed type.
903 * Examples of non-fixed types are GST_TYPE_INT_RANGE and GST_TYPE_LIST.
905 * Returns: TRUE if @caps is fixed
908 gst_caps_is_fixed (const GstCaps * caps)
910 GstStructure *structure;
912 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
914 if (GST_CAPS_LEN (caps) != 1)
917 structure = gst_caps_get_structure_unchecked (caps, 0);
919 return gst_structure_foreach (structure, gst_caps_is_fixed_foreach, NULL);
923 * gst_caps_is_equal_fixed:
924 * @caps1: the #GstCaps to test
925 * @caps2: the #GstCaps to test
927 * Tests if two #GstCaps are equal. This function only works on fixed
930 * Returns: TRUE if the arguments represent the same format
933 gst_caps_is_equal_fixed (const GstCaps * caps1, const GstCaps * caps2)
935 GstStructure *struct1, *struct2;
937 g_return_val_if_fail (gst_caps_is_fixed (caps1), FALSE);
938 g_return_val_if_fail (gst_caps_is_fixed (caps2), FALSE);
940 struct1 = gst_caps_get_structure_unchecked (caps1, 0);
941 struct2 = gst_caps_get_structure_unchecked (caps2, 0);
943 return gst_structure_is_equal (struct1, struct2);
947 * gst_caps_is_always_compatible:
948 * @caps1: the #GstCaps to test
949 * @caps2: the #GstCaps to test
951 * A given #GstCaps structure is always compatible with another if
952 * every media format that is in the first is also contained in the
953 * second. That is, @caps1 is a subset of @caps2.
955 * Returns: TRUE if @caps1 is a subset of @caps2.
958 gst_caps_is_always_compatible (const GstCaps * caps1, const GstCaps * caps2)
960 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
961 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
963 return gst_caps_is_subset (caps1, caps2);
967 * gst_caps_is_subset:
968 * @subset: a #GstCaps
969 * @superset: a potentially greater #GstCaps
971 * Checks if all caps represented by @subset are also represented by @superset.
972 * <note>This function does not work reliably if optional properties for caps
973 * are included on one caps and omitted on the other.</note>
975 * Returns: %TRUE if @subset is a subset of @superset
978 gst_caps_is_subset (const GstCaps * subset, const GstCaps * superset)
980 GstStructure *s1, *s2;
984 g_return_val_if_fail (subset != NULL, FALSE);
985 g_return_val_if_fail (superset != NULL, FALSE);
987 if (CAPS_IS_EMPTY (subset) || CAPS_IS_ANY (superset))
989 if (CAPS_IS_ANY (subset) || CAPS_IS_EMPTY (superset))
992 for (i = GST_CAPS_LEN (subset) - 1; i >= 0; i--) {
993 for (j = GST_CAPS_LEN (superset) - 1; j >= 0; j--) {
994 s1 = gst_caps_get_structure_unchecked (subset, i);
995 s2 = gst_caps_get_structure_unchecked (superset, j);
996 if (gst_structure_is_subset (s1, s2)) {
997 /* If we found a superset, continue with the next
998 * subset structure */
1002 /* If we found no superset for this subset structure
1003 * we return FALSE immediately */
1014 * gst_caps_is_subset_structure:
1016 * @structure: a potential #GstStructure subset of @caps
1018 * Checks if @structure is a subset of @caps. See gst_caps_is_subset()
1019 * for more information.
1021 * Returns: %TRUE if @structure is a subset of @caps
1026 gst_caps_is_subset_structure (const GstCaps * caps,
1027 const GstStructure * structure)
1032 g_return_val_if_fail (caps != NULL, FALSE);
1033 g_return_val_if_fail (structure != NULL, FALSE);
1035 if (CAPS_IS_ANY (caps))
1037 if (CAPS_IS_EMPTY (caps))
1040 for (i = GST_CAPS_LEN (caps) - 1; i >= 0; i--) {
1041 s = gst_caps_get_structure_unchecked (caps, i);
1042 if (gst_structure_is_subset (structure, s)) {
1043 /* If we found a superset return TRUE */
1052 * gst_caps_is_equal:
1053 * @caps1: a #GstCaps
1054 * @caps2: another #GstCaps
1056 * Checks if the given caps represent the same set of caps.
1057 * <note>This function does not work reliably if optional properties for caps
1058 * are included on one caps and omitted on the other.</note>
1060 * This function deals correctly with passing NULL for any of the caps.
1062 * Returns: TRUE if both caps are equal.
1065 gst_caps_is_equal (const GstCaps * caps1, const GstCaps * caps2)
1067 /* FIXME 0.11: NULL pointers are no valid Caps but indicate an error
1068 * So there should be an assertion that caps1 and caps2 != NULL */
1070 /* NULL <-> NULL is allowed here */
1071 if (G_UNLIKELY (caps1 == caps2))
1074 /* one of them NULL => they are different (can't be both NULL because
1075 * we checked that above) */
1076 if (G_UNLIKELY (caps1 == NULL || caps2 == NULL))
1079 if (G_UNLIKELY (gst_caps_is_fixed (caps1) && gst_caps_is_fixed (caps2)))
1080 return gst_caps_is_equal_fixed (caps1, caps2);
1082 return gst_caps_is_subset (caps1, caps2) && gst_caps_is_subset (caps2, caps1);
1085 /* intersect operation */
1088 * gst_caps_can_intersect:
1089 * @caps1: a #GstCaps to intersect
1090 * @caps2: a #GstCaps to intersect
1092 * Tries intersecting @caps1 and @caps2 and reports whether the result would not
1095 * Returns: %TRUE if intersection would be not empty
1100 gst_caps_can_intersect (const GstCaps * caps1, const GstCaps * caps2)
1102 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1103 guint j, k, len1, len2;
1104 GstStructure *struct1;
1105 GstStructure *struct2;
1107 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1108 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1110 /* caps are exactly the same pointers */
1111 if (G_UNLIKELY (caps1 == caps2))
1114 /* empty caps on either side, return empty */
1115 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1118 /* one of the caps is any */
1119 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2)))
1122 /* run zigzag on top line then right line, this preserves the caps order
1123 * much better than a simple loop.
1125 * This algorithm zigzags over the caps structures as demonstrated in
1126 * the folowing matrix:
1129 * +------------- total distance: +-------------
1130 * | 1 2 4 7 0 | 0 1 2 3
1131 * caps2 | 3 5 8 10 1 | 1 2 3 4
1132 * | 6 9 11 12 2 | 2 3 4 5
1134 * First we iterate over the caps1 structures (top line) intersecting
1135 * the structures diagonally down, then we iterate over the caps2
1136 * structures. The result is that the intersections are ordered based on the
1137 * sum of the indexes in the list.
1139 len1 = GST_CAPS_LEN (caps1);
1140 len2 = GST_CAPS_LEN (caps2);
1141 for (i = 0; i < len1 + len2 - 1; i++) {
1142 /* superset index goes from 0 to sgst_caps_structure_intersectuperset->structs->len-1 */
1143 j = MIN (i, len1 - 1);
1144 /* subset index stays 0 until i reaches superset->structs->len, then it
1145 * counts up from 1 to subset->structs->len - 1 */
1146 k = (i > j) ? (i - j) : 0; /* MAX (0, i - j) */
1148 /* now run the diagonal line, end condition is the left or bottom
1151 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1152 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1154 if (gst_structure_can_intersect (struct1, struct2)) {
1157 /* move down left */
1159 if (G_UNLIKELY (j == 0))
1160 break; /* so we don't roll back to G_MAXUINT */
1168 gst_caps_intersect_zig_zag (const GstCaps * caps1, const GstCaps * caps2)
1170 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1171 guint j, k, len1, len2;
1173 GstStructure *struct1;
1174 GstStructure *struct2;
1176 GstStructure *istruct;
1178 /* caps are exactly the same pointers, just copy one caps */
1179 if (G_UNLIKELY (caps1 == caps2))
1180 return _gst_caps_copy (caps1);
1182 /* empty caps on either side, return empty */
1183 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1184 return gst_caps_new_empty ();
1186 /* one of the caps is any, just copy the other caps */
1187 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1188 return _gst_caps_copy (caps2);
1189 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1190 return _gst_caps_copy (caps1);
1192 dest = gst_caps_new_empty ();
1194 /* run zigzag on top line then right line, this preserves the caps order
1195 * much better than a simple loop.
1197 * This algorithm zigzags over the caps structures as demonstrated in
1198 * the folowing matrix:
1206 * First we iterate over the caps1 structures (top line) intersecting
1207 * the structures diagonally down, then we iterate over the caps2
1210 len1 = GST_CAPS_LEN (caps1);
1211 len2 = GST_CAPS_LEN (caps2);
1212 for (i = 0; i < len1 + len2 - 1; i++) {
1213 /* caps1 index goes from 0 to GST_CAPS_LEN (caps1)-1 */
1214 j = MIN (i, len1 - 1);
1215 /* caps2 index stays 0 until i reaches GST_CAPS_LEN (caps1), then it counts
1216 * up from 1 to GST_CAPS_LEN (caps2) - 1 */
1217 k = (i > j) ? (i - j) : 0; /* MAX (0, i - j) */
1219 /* now run the diagonal line, end condition is the left or bottom
1222 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1223 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1225 istruct = gst_structure_intersect (struct1, struct2);
1227 gst_caps_merge_structure (dest, istruct);
1228 /* move down left */
1230 if (G_UNLIKELY (j == 0))
1231 break; /* so we don't roll back to G_MAXUINT */
1239 * gst_caps_intersect_first:
1240 * @caps1: a #GstCaps to intersect
1241 * @caps2: a #GstCaps to intersect
1243 * Creates a new #GstCaps that contains all the formats that are common
1244 * to both @caps1 and @caps2.
1246 * Unlike @gst_caps_intersect, the returned caps will be ordered in a similar
1247 * fashion as @caps1.
1249 * Returns: the new #GstCaps
1252 gst_caps_intersect_first (const GstCaps * caps1, const GstCaps * caps2)
1254 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1255 guint j, len1, len2;
1257 GstStructure *struct1;
1258 GstStructure *struct2;
1260 GstStructure *istruct;
1262 /* caps are exactly the same pointers, just copy one caps */
1263 if (G_UNLIKELY (caps1 == caps2))
1264 return gst_caps_copy (caps1);
1266 /* empty caps on either side, return empty */
1267 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1268 return gst_caps_new_empty ();
1270 /* one of the caps is any, just copy the other caps */
1271 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1272 return gst_caps_copy (caps2);
1273 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1274 return gst_caps_copy (caps1);
1276 dest = gst_caps_new_empty ();
1278 len1 = GST_CAPS_LEN (caps1);
1279 len2 = GST_CAPS_LEN (caps2);
1280 for (i = 0; i < len1; i++) {
1281 struct1 = gst_caps_get_structure_unchecked (caps1, i);
1282 for (j = 0; j < len2; j++) {
1283 struct2 = gst_caps_get_structure_unchecked (caps2, j);
1284 istruct = gst_structure_intersect (struct1, struct2);
1286 gst_caps_merge_structure (dest, istruct);
1294 * gst_caps_intersect_full:
1295 * @caps1: a #GstCaps to intersect
1296 * @caps2: a #GstCaps to intersect
1297 * @mode: The intersection algorithm/mode to use
1299 * Creates a new #GstCaps that contains all the formats that are common
1300 * to both @caps1 and @caps2, the order is defined by the #GstCapsIntersectMode
1303 * Returns: the new #GstCaps
1307 gst_caps_intersect_full (const GstCaps * caps1, const GstCaps * caps2,
1308 GstCapsIntersectMode mode)
1310 g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
1311 g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
1314 case GST_CAPS_INTERSECT_FIRST:
1315 return gst_caps_intersect_first (caps1, caps2);
1317 g_warning ("Unknown caps intersect mode: %d", mode);
1319 case GST_CAPS_INTERSECT_ZIG_ZAG:
1320 return gst_caps_intersect_zig_zag (caps1, caps2);
1325 * gst_caps_intersect:
1326 * @caps1: a #GstCaps to intersect
1327 * @caps2: a #GstCaps to intersect
1329 * Creates a new #GstCaps that contains all the formats that are common
1330 * to both @caps1 and @caps2. Defaults to %GST_CAPS_INTERSECT_ZIG_ZAG mode.
1332 * Returns: the new #GstCaps
1335 gst_caps_intersect (const GstCaps * caps1, const GstCaps * caps2)
1337 return gst_caps_intersect_full (caps1, caps2, GST_CAPS_INTERSECT_ZIG_ZAG);
1341 /* subtract operation */
1345 const GstStructure *subtract_from;
1351 gst_caps_structure_subtract_field (GQuark field_id, const GValue * value,
1354 SubtractionEntry *e = user_data;
1355 GValue subtraction = { 0, };
1356 const GValue *other;
1357 GstStructure *structure;
1359 other = gst_structure_id_get_value (e->subtract_from, field_id);
1363 if (!gst_value_subtract (&subtraction, other, value))
1365 if (gst_value_compare (&subtraction, other) == GST_VALUE_EQUAL) {
1366 g_value_unset (&subtraction);
1369 structure = gst_structure_copy (e->subtract_from);
1370 gst_structure_id_set_value (structure, field_id, &subtraction);
1371 g_value_unset (&subtraction);
1372 e->put_into = g_slist_prepend (e->put_into, structure);
1378 gst_caps_structure_subtract (GSList ** into, const GstStructure * minuend,
1379 const GstStructure * subtrahend)
1384 e.subtract_from = minuend;
1387 ret = gst_structure_foreach ((GstStructure *) subtrahend,
1388 gst_caps_structure_subtract_field, &e);
1394 for (walk = e.put_into; walk; walk = g_slist_next (walk)) {
1395 gst_structure_free (walk->data);
1397 g_slist_free (e.put_into);
1403 * gst_caps_subtract:
1404 * @minuend: #GstCaps to subtract from
1405 * @subtrahend: #GstCaps to subtract
1407 * Subtracts the @subtrahend from the @minuend.
1408 * <note>This function does not work reliably if optional properties for caps
1409 * are included on one caps and omitted on the other.</note>
1411 * Returns: the resulting caps
1414 gst_caps_subtract (const GstCaps * minuend, const GstCaps * subtrahend)
1419 GstCaps *dest = NULL, *src;
1421 g_return_val_if_fail (minuend != NULL, NULL);
1422 g_return_val_if_fail (subtrahend != NULL, NULL);
1424 if (CAPS_IS_EMPTY (minuend) || CAPS_IS_ANY (subtrahend)) {
1425 return gst_caps_new_empty ();
1427 if (CAPS_IS_EMPTY_SIMPLE (subtrahend))
1428 return _gst_caps_copy (minuend);
1430 /* FIXME: Do we want this here or above?
1431 The reason we need this is that there is no definition about what
1432 ANY means for specific types, so it's not possible to reduce ANY partially
1433 You can only remove everything or nothing and that is done above.
1434 Note: there's a test that checks this behaviour. */
1435 g_return_val_if_fail (!CAPS_IS_ANY (minuend), NULL);
1436 sublen = GST_CAPS_LEN (subtrahend);
1437 g_assert (sublen > 0);
1439 src = _gst_caps_copy (minuend);
1440 for (i = 0; i < sublen; i++) {
1443 sub = gst_caps_get_structure_unchecked (subtrahend, i);
1445 gst_caps_unref (src);
1448 dest = gst_caps_new_empty ();
1449 srclen = GST_CAPS_LEN (src);
1450 for (j = 0; j < srclen; j++) {
1451 min = gst_caps_get_structure_unchecked (src, j);
1452 if (gst_structure_get_name_id (min) == gst_structure_get_name_id (sub)) {
1455 if (gst_caps_structure_subtract (&list, min, sub)) {
1458 for (walk = list; walk; walk = g_slist_next (walk)) {
1459 gst_caps_append_structure_unchecked (dest,
1460 (GstStructure *) walk->data);
1462 g_slist_free (list);
1464 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1467 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1470 if (CAPS_IS_EMPTY_SIMPLE (dest)) {
1471 gst_caps_unref (src);
1476 gst_caps_unref (src);
1477 gst_caps_do_simplify (dest);
1481 /* union operation */
1484 static GstStructure *
1485 gst_caps_structure_union (const GstStructure * struct1,
1486 const GstStructure * struct2)
1490 const GstStructureField *field1;
1491 const GstStructureField *field2;
1494 /* FIXME this doesn't actually work */
1496 if (struct1->name != struct2->name)
1499 dest = gst_structure_id_empty_new (struct1->name);
1501 for (i = 0; i < struct1->fields->len; i++) {
1502 GValue dest_value = { 0 };
1504 field1 = GST_STRUCTURE_FIELD (struct1, i);
1505 field2 = gst_structure_id_get_field (struct2, field1->name);
1507 if (field2 == NULL) {
1510 if (gst_value_union (&dest_value, &field1->value, &field2->value)) {
1511 gst_structure_set_value (dest, g_quark_to_string (field1->name),
1514 ret = gst_value_compare (&field1->value, &field2->value);
1525 * @caps1: a #GstCaps to union
1526 * @caps2: a #GstCaps to union
1528 * Creates a new #GstCaps that contains all the formats that are in
1529 * either @caps1 and @caps2.
1531 * Returns: the new #GstCaps
1534 gst_caps_union (const GstCaps * caps1, const GstCaps * caps2)
1539 /* NULL pointers are no correct GstCaps */
1540 g_return_val_if_fail (caps1 != NULL, NULL);
1541 g_return_val_if_fail (caps2 != NULL, NULL);
1543 if (CAPS_IS_EMPTY (caps1))
1544 return _gst_caps_copy (caps2);
1546 if (CAPS_IS_EMPTY (caps2))
1547 return _gst_caps_copy (caps1);
1549 if (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))
1550 return gst_caps_new_any ();
1552 dest1 = _gst_caps_copy (caps1);
1553 dest2 = _gst_caps_copy (caps2);
1554 gst_caps_append (dest1, dest2);
1556 gst_caps_do_simplify (dest1);
1560 /* normalize/simplify operations */
1562 typedef struct _NormalizeForeach
1565 GstStructure *structure;
1570 gst_caps_normalize_foreach (GQuark field_id, const GValue * value, gpointer ptr)
1572 NormalizeForeach *nf = (NormalizeForeach *) ptr;
1576 if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
1577 guint len = gst_value_list_get_size (value);
1578 for (i = 1; i < len; i++) {
1579 const GValue *v = gst_value_list_get_value (value, i);
1580 GstStructure *structure = gst_structure_copy (nf->structure);
1582 gst_structure_id_set_value (structure, field_id, v);
1583 gst_caps_append_structure_unchecked (nf->caps, structure);
1586 gst_value_init_and_copy (&val, gst_value_list_get_value (value, 0));
1587 gst_structure_id_set_value (nf->structure, field_id, &val);
1588 g_value_unset (&val);
1596 * gst_caps_normalize:
1597 * @caps: a #GstCaps to normalize
1599 * Creates a new #GstCaps that represents the same set of formats as
1600 * @caps, but contains no lists. Each list is expanded into separate
1603 * Returns: the new #GstCaps
1606 gst_caps_normalize (const GstCaps * caps)
1608 NormalizeForeach nf;
1612 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
1614 newcaps = _gst_caps_copy (caps);
1617 for (i = 0; i < gst_caps_get_size (newcaps); i++) {
1618 nf.structure = gst_caps_get_structure_unchecked (newcaps, i);
1620 while (!gst_structure_foreach (nf.structure,
1621 gst_caps_normalize_foreach, &nf));
1628 gst_caps_compare_structures (gconstpointer one, gconstpointer two)
1631 const GstStructure *struct1 = *((const GstStructure **) one);
1632 const GstStructure *struct2 = *((const GstStructure **) two);
1634 /* FIXME: this orders alphabetically, but ordering the quarks might be faster
1635 So what's the best way? */
1636 ret = strcmp (gst_structure_get_name (struct1),
1637 gst_structure_get_name (struct2));
1641 return gst_structure_n_fields (struct2) - gst_structure_n_fields (struct1);
1648 GstStructure *compare;
1653 gst_caps_structure_figure_out_union (GQuark field_id, const GValue * value,
1656 UnionField *u = user_data;
1657 const GValue *val = gst_structure_id_get_value (u->compare, field_id);
1661 g_value_unset (&u->value);
1664 if (gst_value_compare (val, value) == GST_VALUE_EQUAL)
1667 g_value_unset (&u->value);
1671 gst_value_union (&u->value, val, value);
1676 gst_caps_structure_simplify (GstStructure ** result,
1677 const GstStructure * simplify, GstStructure * compare)
1680 UnionField field = { 0, {0,}, NULL };
1682 /* try to subtract to get a real subset */
1683 if (gst_caps_structure_subtract (&list, simplify, compare)) {
1684 if (list == NULL) { /* no result */
1687 } else if (list->next == NULL) { /* one result */
1688 *result = list->data;
1689 g_slist_free (list);
1691 } else { /* multiple results */
1692 g_slist_foreach (list, (GFunc) gst_structure_free, NULL);
1693 g_slist_free (list);
1698 /* try to union both structs */
1699 field.compare = compare;
1700 if (gst_structure_foreach ((GstStructure *) simplify,
1701 gst_caps_structure_figure_out_union, &field)) {
1702 gboolean ret = FALSE;
1704 /* now we know all of simplify's fields are the same in compare
1705 * but at most one field: field.name */
1706 if (G_IS_VALUE (&field.value)) {
1707 if (gst_structure_n_fields (simplify) == gst_structure_n_fields (compare)) {
1708 gst_structure_id_set_value (compare, field.name, &field.value);
1712 g_value_unset (&field.value);
1713 } else if (gst_structure_n_fields (simplify) <=
1714 gst_structure_n_fields (compare)) {
1715 /* compare is just more specific, will be optimized away later */
1716 /* FIXME: do this here? */
1717 GST_LOG ("found a case that will be optimized later.");
1719 gchar *one = gst_structure_to_string (simplify);
1720 gchar *two = gst_structure_to_string (compare);
1723 ("caps mismatch: structures %s and %s claim to be possible to unify, but aren't",
1735 gst_caps_switch_structures (GstCaps * caps, GstStructure * old,
1736 GstStructure * new, gint i)
1738 gst_structure_set_parent_refcount (old, NULL);
1739 gst_structure_free (old);
1740 gst_structure_set_parent_refcount (new, &GST_CAPS_REFCOUNT (caps));
1741 g_ptr_array_index (GST_CAPS_ARRAY (caps), i) = new;
1745 * gst_caps_do_simplify:
1746 * @caps: a #GstCaps to simplify
1748 * Modifies the given @caps inplace into a representation that represents the
1749 * same set of formats, but in a simpler form. Component structures that are
1750 * identical are merged. Component structures that have values that can be
1751 * merged are also merged.
1753 * Returns: TRUE, if the caps could be simplified
1756 gst_caps_do_simplify (GstCaps * caps)
1758 GstStructure *simplify, *compare, *result = NULL;
1760 gboolean changed = FALSE;
1762 g_return_val_if_fail (caps != NULL, FALSE);
1763 g_return_val_if_fail (IS_WRITABLE (caps), FALSE);
1765 if (gst_caps_get_size (caps) < 2)
1768 g_ptr_array_sort (GST_CAPS_ARRAY (caps), gst_caps_compare_structures);
1770 start = GST_CAPS_LEN (caps) - 1;
1771 for (i = GST_CAPS_LEN (caps) - 1; i >= 0; i--) {
1772 simplify = gst_caps_get_structure_unchecked (caps, i);
1773 if (gst_structure_get_name_id (simplify) !=
1774 gst_structure_get_name_id (gst_caps_get_structure_unchecked (caps,
1777 for (j = start; j >= 0; j--) {
1780 compare = gst_caps_get_structure_unchecked (caps, j);
1781 if (gst_structure_get_name_id (simplify) !=
1782 gst_structure_get_name_id (compare)) {
1785 if (gst_caps_structure_simplify (&result, simplify, compare)) {
1787 gst_caps_switch_structures (caps, simplify, result, i);
1790 gst_caps_remove_structure (caps, i);
1802 /* gst_caps_do_simplify (caps); */
1808 * @caps: a #GstCaps to fixate
1810 * Modifies the given @caps inplace into a representation with only fixed
1811 * values. First the caps will be truncated and then the first structure will be
1812 * fixated with gst_structure_fixate(). @caps should be writable.
1815 gst_caps_fixate (GstCaps * caps)
1819 g_return_if_fail (GST_IS_CAPS (caps));
1820 g_return_if_fail (IS_WRITABLE (caps));
1822 /* default fixation */
1823 gst_caps_truncate (caps);
1824 s = gst_caps_get_structure (caps, 0);
1825 gst_structure_fixate (s);
1831 * gst_caps_to_string:
1834 * Converts @caps to a string representation. This string representation
1835 * can be converted back to a #GstCaps by gst_caps_from_string().
1837 * For debugging purposes its easier to do something like this:
1839 * GST_LOG ("caps are %" GST_PTR_FORMAT, caps);
1841 * This prints the caps in human readble form.
1843 * Returns: (transfer full): a newly allocated string representing @caps.
1846 gst_caps_to_string (const GstCaps * caps)
1848 guint i, slen, clen;
1851 /* NOTE: This function is potentially called by the debug system,
1852 * so any calls to gst_log() (and GST_DEBUG(), GST_LOG(), etc.)
1853 * should be careful to avoid recursion. This includes any functions
1854 * called by gst_caps_to_string. In particular, calls should
1855 * not use the GST_PTR_FORMAT extension. */
1858 return g_strdup ("NULL");
1860 if (CAPS_IS_ANY (caps)) {
1861 return g_strdup ("ANY");
1863 if (CAPS_IS_EMPTY_SIMPLE (caps)) {
1864 return g_strdup ("EMPTY");
1867 /* estimate a rough string length to avoid unnecessary reallocs in GString */
1869 clen = GST_CAPS_LEN (caps);
1870 for (i = 0; i < clen; i++) {
1872 STRUCTURE_ESTIMATED_STRING_LEN (gst_caps_get_structure_unchecked (caps,
1876 s = g_string_sized_new (slen);
1877 for (i = 0; i < clen; i++) {
1878 GstStructure *structure;
1881 /* ';' is now added by gst_structure_to_string */
1882 g_string_append_c (s, ' ');
1885 structure = gst_caps_get_structure_unchecked (caps, i);
1886 priv_gst_structure_append_to_gstring (structure, s);
1888 if (s->len && s->str[s->len - 1] == ';') {
1889 /* remove latest ';' */
1890 s->str[--s->len] = '\0';
1892 return g_string_free (s, FALSE);
1896 gst_caps_from_string_inplace (GstCaps * caps, const gchar * string)
1898 GstStructure *structure;
1901 if (strcmp ("ANY", string) == 0) {
1902 GST_CAPS_FLAGS (caps) = GST_CAPS_FLAGS_ANY;
1905 if (strcmp ("EMPTY", string) == 0) {
1909 structure = gst_structure_from_string (string, &s);
1910 if (structure == NULL) {
1913 gst_caps_append_structure_unchecked (caps, structure);
1917 while (g_ascii_isspace (*s))
1922 structure = gst_structure_from_string (s, &s);
1923 if (structure == NULL) {
1926 gst_caps_append_structure_unchecked (caps, structure);
1934 * gst_caps_from_string:
1935 * @string: a string to convert to #GstCaps
1937 * Converts @caps from a string representation.
1939 * Returns: (transfer full): a newly allocated #GstCaps
1942 gst_caps_from_string (const gchar * string)
1946 g_return_val_if_fail (string, FALSE);
1948 caps = gst_caps_new_empty ();
1949 if (gst_caps_from_string_inplace (caps, string)) {
1952 gst_caps_unref (caps);
1958 gst_caps_transform_to_string (const GValue * src_value, GValue * dest_value)
1960 g_return_if_fail (G_IS_VALUE (src_value));
1961 g_return_if_fail (G_IS_VALUE (dest_value));
1962 g_return_if_fail (G_VALUE_HOLDS (src_value, GST_TYPE_CAPS));
1963 g_return_if_fail (G_VALUE_HOLDS (dest_value, G_TYPE_STRING)
1964 || G_VALUE_HOLDS (dest_value, G_TYPE_POINTER));
1966 g_value_take_string (dest_value,
1967 gst_caps_to_string (gst_value_get_caps (src_value)));