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_simple:
237 * @media_type: the media type of the structure
238 * @fieldname: first field to set
239 * @...: additional arguments
241 * Creates a new #GstCaps that contains one #GstStructure. The
242 * structure is defined by the arguments, which have the same format
243 * as gst_structure_new().
244 * Caller is responsible for unreffing the returned caps.
246 * Returns: (transfer full): the new #GstCaps
249 gst_caps_new_simple (const char *media_type, const char *fieldname, ...)
252 GstStructure *structure;
255 caps = gst_caps_new_empty ();
257 va_start (var_args, fieldname);
258 structure = gst_structure_new_valist (media_type, fieldname, var_args);
262 gst_caps_append_structure_unchecked (caps, structure);
264 gst_caps_replace (&caps, NULL);
271 * @struct1: the first structure to add
272 * @...: additional structures to add
274 * Creates a new #GstCaps and adds all the structures listed as
275 * arguments. The list must be NULL-terminated. The structures
276 * are not copied; the returned #GstCaps owns the structures.
278 * Returns: (transfer full): the new #GstCaps
281 gst_caps_new_full (GstStructure * struct1, ...)
286 va_start (var_args, struct1);
287 caps = gst_caps_new_full_valist (struct1, var_args);
294 * gst_caps_new_full_valist:
295 * @structure: the first structure to add
296 * @var_args: 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_valist (GstStructure * structure, va_list var_args)
309 caps = gst_caps_new_empty ();
312 gst_caps_append_structure_unchecked (caps, structure);
313 structure = va_arg (var_args, GstStructure *);
320 gst_static_caps_get_type (void)
322 static GType staticcaps_type = 0;
324 if (G_UNLIKELY (staticcaps_type == 0)) {
325 staticcaps_type = g_pointer_type_register_static ("GstStaticCaps");
327 return staticcaps_type;
332 * gst_static_caps_get:
333 * @static_caps: the #GstStaticCaps to convert
335 * Converts a #GstStaticCaps to a #GstCaps.
337 * Returns: (transfer full): a pointer to the #GstCaps. Unref after usage.
338 * Since the core holds an additional ref to the returned caps,
339 * use gst_caps_make_writable() on the returned caps to modify it.
342 gst_static_caps_get (GstStaticCaps * static_caps)
346 g_return_val_if_fail (static_caps != NULL, NULL);
348 caps = (GstCaps *) static_caps;
350 /* refcount is 0 when we need to convert */
351 if (G_UNLIKELY (GST_CAPS_REFCOUNT_VALUE (caps) == 0)) {
355 G_LOCK (static_caps_lock);
356 /* check if other thread already updated */
357 if (G_UNLIKELY (GST_CAPS_REFCOUNT_VALUE (caps) > 0))
360 string = static_caps->string;
362 if (G_UNLIKELY (string == NULL))
365 GST_CAT_TRACE (GST_CAT_CAPS, "creating %p", static_caps);
367 /* we construct the caps on the stack, then copy over the struct into our
368 * real caps, refcount last. We do this because we must leave the refcount
369 * of the result caps to 0 so that other threads don't run away with the
370 * caps while we are constructing it. */
371 gst_caps_init (&temp, sizeof (GstCaps));
373 /* convert to string */
374 if (G_UNLIKELY (!gst_caps_from_string_inplace (&temp, string)))
375 g_critical ("Could not convert static caps \"%s\"", string);
377 GST_MINI_OBJECT_REFCOUNT (&temp) = 0;
378 memcpy (caps, &temp, sizeof (GstCaps));
381 GST_CAT_TRACE (GST_CAT_CAPS, "created %p", static_caps);
383 G_UNLOCK (static_caps_lock);
385 /* ref the caps, makes it not writable */
393 G_UNLOCK (static_caps_lock);
394 g_warning ("static caps %p string is NULL", static_caps);
400 * gst_static_caps_cleanup:
401 * @static_caps: the #GstStaticCaps to convert
403 * Clean up the caps contained in @static_caps when the refcount is 0.
406 gst_static_caps_cleanup (GstStaticCaps * static_caps)
408 GstCaps *caps = (GstCaps *) static_caps;
410 /* FIXME: this is not threadsafe */
411 if (GST_CAPS_REFCOUNT_VALUE (caps) == 1) {
412 GstStructure *structure;
415 clen = GST_CAPS_LEN (caps);
417 for (i = 0; i < clen; i++) {
418 structure = (GstStructure *) gst_caps_get_structure (caps, i);
419 gst_structure_set_parent_refcount (structure, NULL);
420 gst_structure_free (structure);
422 g_ptr_array_free (GST_CAPS_ARRAY (caps), TRUE);
423 GST_CAPS_REFCOUNT (caps) = 0;
429 static GstStructure *
430 gst_caps_remove_and_get_structure (GstCaps * caps, guint idx)
432 /* don't use index_fast, gst_caps_do_simplify relies on the order */
433 GstStructure *s = g_ptr_array_remove_index (GST_CAPS_ARRAY (caps), idx);
435 gst_structure_set_parent_refcount (s, NULL);
440 * gst_caps_steal_structure:
441 * @caps: the #GstCaps to retrieve from
442 * @index: Index of the structure to retrieve
444 * Retrieves the stucture with the given index from the list of structures
445 * contained in @caps. The caller becomes the owner of the returned structure.
447 * Returns: (transfer full): a pointer to the #GstStructure corresponding
453 gst_caps_steal_structure (GstCaps * caps, guint index)
455 g_return_val_if_fail (caps != NULL, NULL);
456 g_return_val_if_fail (IS_WRITABLE (caps), NULL);
458 if (G_UNLIKELY (index >= GST_CAPS_LEN (caps)))
461 return gst_caps_remove_and_get_structure (caps, index);
466 * @caps1: the #GstCaps that will be appended to
467 * @caps2: (transfer full): the #GstCaps to append
469 * Appends the structures contained in @caps2 to @caps1. The structures in
470 * @caps2 are not copied -- they are transferred to @caps1, and then @caps2 is
471 * freed. If either caps is ANY, the resulting caps will be ANY.
474 gst_caps_append (GstCaps * caps1, GstCaps * caps2)
476 GstStructure *structure;
479 g_return_if_fail (GST_IS_CAPS (caps1));
480 g_return_if_fail (GST_IS_CAPS (caps2));
481 g_return_if_fail (IS_WRITABLE (caps1));
482 g_return_if_fail (IS_WRITABLE (caps2));
484 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))) {
485 /* FIXME: this leaks */
486 GST_CAPS_FLAGS (caps1) |= GST_CAPS_FLAGS_ANY;
487 for (i = GST_CAPS_LEN (caps2) - 1; i >= 0; i--) {
488 structure = gst_caps_remove_and_get_structure (caps2, i);
489 gst_structure_free (structure);
492 for (i = GST_CAPS_LEN (caps2); i; i--) {
493 structure = gst_caps_remove_and_get_structure (caps2, 0);
494 gst_caps_append_structure_unchecked (caps1, structure);
497 gst_caps_unref (caps2); /* guaranteed to free it */
502 * @caps1: the #GstCaps that will take the new entries
503 * @caps2: (transfer full): the #GstCaps to merge in
505 * Appends the structures contained in @caps2 to @caps1 if they are not yet
506 * expressed by @caps1. The structures in @caps2 are not copied -- they are
507 * transferred to @caps1, and then @caps2 is freed.
508 * If either caps is ANY, the resulting caps will be ANY.
513 gst_caps_merge (GstCaps * caps1, GstCaps * caps2)
515 GstStructure *structure;
518 g_return_if_fail (GST_IS_CAPS (caps1));
519 g_return_if_fail (GST_IS_CAPS (caps2));
520 g_return_if_fail (IS_WRITABLE (caps1));
521 g_return_if_fail (IS_WRITABLE (caps2));
523 if (G_UNLIKELY (CAPS_IS_ANY (caps1))) {
524 for (i = GST_CAPS_LEN (caps2) - 1; i >= 0; i--) {
525 structure = gst_caps_remove_and_get_structure (caps2, i);
526 gst_structure_free (structure);
528 } else if (G_UNLIKELY (CAPS_IS_ANY (caps2))) {
529 GST_CAPS_FLAGS (caps1) |= GST_CAPS_FLAGS_ANY;
530 for (i = GST_CAPS_LEN (caps1) - 1; i >= 0; i--) {
531 structure = gst_caps_remove_and_get_structure (caps1, i);
532 gst_structure_free (structure);
535 for (i = GST_CAPS_LEN (caps2); i; i--) {
536 structure = gst_caps_remove_and_get_structure (caps2, 0);
537 gst_caps_merge_structure (caps1, structure);
540 GstCaps *com = gst_caps_intersect (caps1, caps2);
541 GstCaps *add = gst_caps_subtract (caps2, com);
543 GST_DEBUG ("common : %d", gst_caps_get_size (com));
544 GST_DEBUG ("adding : %d", gst_caps_get_size (add));
545 gst_caps_append (caps1, add);
546 gst_caps_unref (com);
549 gst_caps_unref (caps2); /* guaranteed to free it */
553 * gst_caps_append_structure:
554 * @caps: the #GstCaps that will be appended to
555 * @structure: (transfer full): the #GstStructure to append
557 * Appends @structure to @caps. The structure is not copied; @caps
558 * becomes the owner of @structure.
561 gst_caps_append_structure (GstCaps * caps, GstStructure * structure)
563 g_return_if_fail (GST_IS_CAPS (caps));
564 g_return_if_fail (IS_WRITABLE (caps));
566 if (G_LIKELY (structure)) {
567 gst_caps_append_structure_unchecked (caps, structure);
572 * gst_caps_remove_structure:
573 * @caps: the #GstCaps to remove from
574 * @idx: Index of the structure to remove
576 * removes the stucture with the given index from the list of structures
577 * contained in @caps.
580 gst_caps_remove_structure (GstCaps * caps, guint idx)
582 GstStructure *structure;
584 g_return_if_fail (caps != NULL);
585 g_return_if_fail (idx <= gst_caps_get_size (caps));
586 g_return_if_fail (IS_WRITABLE (caps));
588 structure = gst_caps_remove_and_get_structure (caps, idx);
589 gst_structure_free (structure);
593 * gst_caps_merge_structure:
594 * @caps: the #GstCaps that will the new structure
595 * @structure: (transfer full): the #GstStructure to merge
597 * Appends @structure to @caps if its not already expressed by @caps. The
598 * structure is not copied; @caps becomes the owner of @structure.
601 gst_caps_merge_structure (GstCaps * caps, GstStructure * structure)
603 g_return_if_fail (GST_IS_CAPS (caps));
604 g_return_if_fail (IS_WRITABLE (caps));
606 if (G_LIKELY (structure)) {
607 GstStructure *structure1;
609 gboolean unique = TRUE;
611 /* check each structure */
612 for (i = GST_CAPS_LEN (caps) - 1; i >= 0; i--) {
613 structure1 = gst_caps_get_structure_unchecked (caps, i);
614 /* if structure is a subset of structure1, then skip it */
615 if (gst_structure_is_subset (structure, structure1)) {
621 gst_caps_append_structure_unchecked (caps, structure);
623 gst_structure_free (structure);
632 * Gets the number of structures contained in @caps.
634 * Returns: the number of structures that @caps contains
637 gst_caps_get_size (const GstCaps * caps)
639 g_return_val_if_fail (GST_IS_CAPS (caps), 0);
641 return GST_CAPS_LEN (caps);
645 * gst_caps_get_structure:
647 * @index: the index of the structure
649 * Finds the structure in @caps that has the index @index, and
652 * WARNING: This function takes a const GstCaps *, but returns a
653 * non-const GstStructure *. This is for programming convenience --
654 * the caller should be aware that structures inside a constant
655 * #GstCaps should not be modified. However, if you know the caps
656 * are writable, either because you have just copied them or made
657 * them writable with gst_caps_make_writable(), you may modify the
658 * structure returned in the usual way, e.g. with functions like
659 * gst_structure_set().
661 * You do not need to free or unref the structure returned, it
662 * belongs to the #GstCaps.
664 * Returns: (transfer none): a pointer to the #GstStructure corresponding
668 gst_caps_get_structure (const GstCaps * caps, guint index)
670 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
671 g_return_val_if_fail (index < GST_CAPS_LEN (caps), NULL);
673 return gst_caps_get_structure_unchecked (caps, index);
678 * @caps: the #GstCaps to copy
679 * @nth: the nth structure to copy
681 * Creates a new #GstCaps and appends a copy of the nth structure
682 * contained in @caps.
684 * Returns: (transfer full): the new #GstCaps
687 gst_caps_copy_nth (const GstCaps * caps, guint nth)
690 GstStructure *structure;
692 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
694 newcaps = gst_caps_new_empty ();
695 GST_CAPS_FLAGS (newcaps) = GST_CAPS_FLAGS (caps);
697 if (G_LIKELY (GST_CAPS_LEN (caps) > nth)) {
698 structure = gst_caps_get_structure_unchecked (caps, nth);
699 gst_caps_append_structure_unchecked (newcaps,
700 gst_structure_copy (structure));
708 * @caps: the #GstCaps to truncate
710 * Destructively discard all but the first structure from @caps. Useful when
711 * fixating. @caps must be writable.
714 gst_caps_truncate (GstCaps * caps)
718 g_return_if_fail (GST_IS_CAPS (caps));
719 g_return_if_fail (IS_WRITABLE (caps));
721 i = GST_CAPS_LEN (caps) - 1;
724 gst_caps_remove_structure (caps, i--);
728 * gst_caps_set_value:
729 * @caps: a writable caps
730 * @field: name of the field to set
731 * @value: value to set the field to
733 * Sets the given @field on all structures of @caps to the given @value.
734 * This is a convenience function for calling gst_structure_set_value() on
735 * all structures of @caps.
740 gst_caps_set_value (GstCaps * caps, const char *field, const GValue * value)
744 g_return_if_fail (GST_IS_CAPS (caps));
745 g_return_if_fail (IS_WRITABLE (caps));
746 g_return_if_fail (field != NULL);
747 g_return_if_fail (G_IS_VALUE (value));
749 len = GST_CAPS_LEN (caps);
750 for (i = 0; i < len; i++) {
751 GstStructure *structure = gst_caps_get_structure_unchecked (caps, i);
752 gst_structure_set_value (structure, field, value);
757 * gst_caps_set_simple_valist:
758 * @caps: the #GstCaps to set
759 * @field: first field to set
760 * @varargs: additional parameters
762 * Sets fields in a #GstCaps. The arguments must be passed in the same
763 * manner as gst_structure_set(), and be NULL-terminated.
764 * <note>Prior to GStreamer version 0.10.26, this function failed when
765 * @caps was not simple. If your code needs to work with those versions
766 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
767 * is %TRUE for @caps.</note>
770 gst_caps_set_simple_valist (GstCaps * caps, const char *field, va_list varargs)
772 GValue value = { 0, };
774 g_return_if_fail (GST_IS_CAPS (caps));
775 g_return_if_fail (IS_WRITABLE (caps));
781 type = va_arg (varargs, GType);
783 if (G_UNLIKELY (type == G_TYPE_DATE)) {
784 g_warning ("Don't use G_TYPE_DATE, use GST_TYPE_DATE instead\n");
785 type = GST_TYPE_DATE;
787 G_VALUE_COLLECT_INIT (&value, type, varargs, 0, &err);
788 if (G_UNLIKELY (err)) {
789 g_critical ("%s", err);
793 gst_caps_set_value (caps, field, &value);
795 g_value_unset (&value);
797 field = va_arg (varargs, const gchar *);
802 * gst_caps_set_simple:
803 * @caps: the #GstCaps to set
804 * @field: first field to set
805 * @...: additional parameters
807 * Sets fields in a #GstCaps. The arguments must be passed in the same
808 * manner as gst_structure_set(), and be NULL-terminated.
809 * <note>Prior to GStreamer version 0.10.26, this function failed when
810 * @caps was not simple. If your code needs to work with those versions
811 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
812 * is %TRUE for @caps.</note>
815 gst_caps_set_simple (GstCaps * caps, const char *field, ...)
819 g_return_if_fail (GST_IS_CAPS (caps));
820 g_return_if_fail (IS_WRITABLE (caps));
822 va_start (var_args, field);
823 gst_caps_set_simple_valist (caps, field, var_args);
831 * @caps: the #GstCaps to test
833 * Determines if @caps represents any media format.
835 * Returns: TRUE if @caps represents any format.
838 gst_caps_is_any (const GstCaps * caps)
840 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
842 return (CAPS_IS_ANY (caps));
847 * @caps: the #GstCaps to test
849 * Determines if @caps represents no media formats.
851 * Returns: TRUE if @caps represents no formats.
854 gst_caps_is_empty (const GstCaps * caps)
856 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
858 if (CAPS_IS_ANY (caps))
861 return CAPS_IS_EMPTY_SIMPLE (caps);
865 gst_caps_is_fixed_foreach (GQuark field_id, const GValue * value,
868 return gst_value_is_fixed (value);
873 * @caps: the #GstCaps to test
875 * Fixed #GstCaps describe exactly one format, that is, they have exactly
876 * one structure, and each field in the structure describes a fixed type.
877 * Examples of non-fixed types are GST_TYPE_INT_RANGE and GST_TYPE_LIST.
879 * Returns: TRUE if @caps is fixed
882 gst_caps_is_fixed (const GstCaps * caps)
884 GstStructure *structure;
886 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
888 if (GST_CAPS_LEN (caps) != 1)
891 structure = gst_caps_get_structure_unchecked (caps, 0);
893 return gst_structure_foreach (structure, gst_caps_is_fixed_foreach, NULL);
897 * gst_caps_is_equal_fixed:
898 * @caps1: the #GstCaps to test
899 * @caps2: the #GstCaps to test
901 * Tests if two #GstCaps are equal. This function only works on fixed
904 * Returns: TRUE if the arguments represent the same format
907 gst_caps_is_equal_fixed (const GstCaps * caps1, const GstCaps * caps2)
909 GstStructure *struct1, *struct2;
911 g_return_val_if_fail (gst_caps_is_fixed (caps1), FALSE);
912 g_return_val_if_fail (gst_caps_is_fixed (caps2), FALSE);
914 struct1 = gst_caps_get_structure_unchecked (caps1, 0);
915 struct2 = gst_caps_get_structure_unchecked (caps2, 0);
917 return gst_structure_is_equal (struct1, struct2);
921 * gst_caps_is_always_compatible:
922 * @caps1: the #GstCaps to test
923 * @caps2: the #GstCaps to test
925 * A given #GstCaps structure is always compatible with another if
926 * every media format that is in the first is also contained in the
927 * second. That is, @caps1 is a subset of @caps2.
929 * Returns: TRUE if @caps1 is a subset of @caps2.
932 gst_caps_is_always_compatible (const GstCaps * caps1, const GstCaps * caps2)
934 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
935 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
937 return gst_caps_is_subset (caps1, caps2);
941 * gst_caps_is_subset:
942 * @subset: a #GstCaps
943 * @superset: a potentially greater #GstCaps
945 * Checks if all caps represented by @subset are also represented by @superset.
946 * <note>This function does not work reliably if optional properties for caps
947 * are included on one caps and omitted on the other.</note>
949 * Returns: %TRUE if @subset is a subset of @superset
952 gst_caps_is_subset (const GstCaps * subset, const GstCaps * superset)
954 GstStructure *s1, *s2;
958 g_return_val_if_fail (subset != NULL, FALSE);
959 g_return_val_if_fail (superset != NULL, FALSE);
961 if (CAPS_IS_EMPTY (subset) || CAPS_IS_ANY (superset))
963 if (CAPS_IS_ANY (subset) || CAPS_IS_EMPTY (superset))
966 for (i = GST_CAPS_LEN (subset) - 1; i >= 0; i--) {
967 for (j = GST_CAPS_LEN (superset) - 1; j >= 0; j--) {
968 s1 = gst_caps_get_structure_unchecked (subset, i);
969 s2 = gst_caps_get_structure_unchecked (superset, j);
970 if (gst_structure_is_subset (s1, s2)) {
971 /* If we found a superset, continue with the next
972 * subset structure */
976 /* If we found no superset for this subset structure
977 * we return FALSE immediately */
988 * gst_caps_is_subset_structure:
990 * @structure: a potential #GstStructure subset of @caps
992 * Checks if @structure is a subset of @caps. See gst_caps_is_subset()
993 * for more information.
995 * Returns: %TRUE if @structure is a subset of @caps
1000 gst_caps_is_subset_structure (const GstCaps * caps,
1001 const GstStructure * structure)
1006 g_return_val_if_fail (caps != NULL, FALSE);
1007 g_return_val_if_fail (structure != NULL, FALSE);
1009 if (CAPS_IS_ANY (caps))
1011 if (CAPS_IS_EMPTY (caps))
1014 for (i = GST_CAPS_LEN (caps) - 1; i >= 0; i--) {
1015 s = gst_caps_get_structure_unchecked (caps, i);
1016 if (gst_structure_is_subset (structure, s)) {
1017 /* If we found a superset return TRUE */
1026 * gst_caps_is_equal:
1027 * @caps1: a #GstCaps
1028 * @caps2: another #GstCaps
1030 * Checks if the given caps represent the same set of caps.
1031 * <note>This function does not work reliably if optional properties for caps
1032 * are included on one caps and omitted on the other.</note>
1034 * This function deals correctly with passing NULL for any of the caps.
1036 * Returns: TRUE if both caps are equal.
1039 gst_caps_is_equal (const GstCaps * caps1, const GstCaps * caps2)
1041 /* FIXME 0.11: NULL pointers are no valid Caps but indicate an error
1042 * So there should be an assertion that caps1 and caps2 != NULL */
1044 /* NULL <-> NULL is allowed here */
1045 if (G_UNLIKELY (caps1 == caps2))
1048 /* one of them NULL => they are different (can't be both NULL because
1049 * we checked that above) */
1050 if (G_UNLIKELY (caps1 == NULL || caps2 == NULL))
1053 if (G_UNLIKELY (gst_caps_is_fixed (caps1) && gst_caps_is_fixed (caps2)))
1054 return gst_caps_is_equal_fixed (caps1, caps2);
1056 return gst_caps_is_subset (caps1, caps2) && gst_caps_is_subset (caps2, caps1);
1059 /* intersect operation */
1062 * gst_caps_can_intersect:
1063 * @caps1: a #GstCaps to intersect
1064 * @caps2: a #GstCaps to intersect
1066 * Tries intersecting @caps1 and @caps2 and reports whether the result would not
1069 * Returns: %TRUE if intersection would be not empty
1074 gst_caps_can_intersect (const GstCaps * caps1, const GstCaps * caps2)
1076 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1077 guint j, k, len1, len2;
1078 GstStructure *struct1;
1079 GstStructure *struct2;
1081 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1082 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1084 /* caps are exactly the same pointers */
1085 if (G_UNLIKELY (caps1 == caps2))
1088 /* empty caps on either side, return empty */
1089 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1092 /* one of the caps is any */
1093 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2)))
1096 /* run zigzag on top line then right line, this preserves the caps order
1097 * much better than a simple loop.
1099 * This algorithm zigzags over the caps structures as demonstrated in
1100 * the folowing matrix:
1103 * +------------- total distance: +-------------
1104 * | 1 2 4 7 0 | 0 1 2 3
1105 * caps2 | 3 5 8 10 1 | 1 2 3 4
1106 * | 6 9 11 12 2 | 2 3 4 5
1108 * First we iterate over the caps1 structures (top line) intersecting
1109 * the structures diagonally down, then we iterate over the caps2
1110 * structures. The result is that the intersections are ordered based on the
1111 * sum of the indexes in the list.
1113 len1 = GST_CAPS_LEN (caps1);
1114 len2 = GST_CAPS_LEN (caps2);
1115 for (i = 0; i < len1 + len2 - 1; i++) {
1116 /* superset index goes from 0 to sgst_caps_structure_intersectuperset->structs->len-1 */
1117 j = MIN (i, len1 - 1);
1118 /* subset index stays 0 until i reaches superset->structs->len, then it
1119 * counts up from 1 to subset->structs->len - 1 */
1120 k = (i > j) ? (i - j) : 0; /* MAX (0, i - j) */
1122 /* now run the diagonal line, end condition is the left or bottom
1125 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1126 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1128 if (gst_structure_can_intersect (struct1, struct2)) {
1131 /* move down left */
1133 if (G_UNLIKELY (j == 0))
1134 break; /* so we don't roll back to G_MAXUINT */
1142 gst_caps_intersect_zig_zag (const GstCaps * caps1, const GstCaps * caps2)
1144 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1145 guint j, k, len1, len2;
1147 GstStructure *struct1;
1148 GstStructure *struct2;
1150 GstStructure *istruct;
1152 /* caps are exactly the same pointers, just copy one caps */
1153 if (G_UNLIKELY (caps1 == caps2))
1154 return _gst_caps_copy (caps1);
1156 /* empty caps on either side, return empty */
1157 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1158 return gst_caps_new_empty ();
1160 /* one of the caps is any, just copy the other caps */
1161 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1162 return _gst_caps_copy (caps2);
1163 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1164 return _gst_caps_copy (caps1);
1166 dest = gst_caps_new_empty ();
1168 /* run zigzag on top line then right line, this preserves the caps order
1169 * much better than a simple loop.
1171 * This algorithm zigzags over the caps structures as demonstrated in
1172 * the folowing matrix:
1180 * First we iterate over the caps1 structures (top line) intersecting
1181 * the structures diagonally down, then we iterate over the caps2
1184 len1 = GST_CAPS_LEN (caps1);
1185 len2 = GST_CAPS_LEN (caps2);
1186 for (i = 0; i < len1 + len2 - 1; i++) {
1187 /* caps1 index goes from 0 to GST_CAPS_LEN (caps1)-1 */
1188 j = MIN (i, len1 - 1);
1189 /* caps2 index stays 0 until i reaches GST_CAPS_LEN (caps1), then it counts
1190 * up from 1 to GST_CAPS_LEN (caps2) - 1 */
1191 k = (i > j) ? (i - j) : 0; /* MAX (0, i - j) */
1193 /* now run the diagonal line, end condition is the left or bottom
1196 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1197 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1199 istruct = gst_structure_intersect (struct1, struct2);
1201 gst_caps_merge_structure (dest, istruct);
1202 /* move down left */
1204 if (G_UNLIKELY (j == 0))
1205 break; /* so we don't roll back to G_MAXUINT */
1213 * gst_caps_intersect_first:
1214 * @caps1: a #GstCaps to intersect
1215 * @caps2: a #GstCaps to intersect
1217 * Creates a new #GstCaps that contains all the formats that are common
1218 * to both @caps1 and @caps2.
1220 * Unlike @gst_caps_intersect, the returned caps will be ordered in a similar
1221 * fashion as @caps1.
1223 * Returns: the new #GstCaps
1226 gst_caps_intersect_first (const GstCaps * caps1, const GstCaps * caps2)
1228 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1229 guint j, len1, len2;
1231 GstStructure *struct1;
1232 GstStructure *struct2;
1234 GstStructure *istruct;
1236 /* caps are exactly the same pointers, just copy one caps */
1237 if (G_UNLIKELY (caps1 == caps2))
1238 return gst_caps_copy (caps1);
1240 /* empty caps on either side, return empty */
1241 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1242 return gst_caps_new_empty ();
1244 /* one of the caps is any, just copy the other caps */
1245 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1246 return gst_caps_copy (caps2);
1247 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1248 return gst_caps_copy (caps1);
1250 dest = gst_caps_new_empty ();
1252 len1 = GST_CAPS_LEN (caps1);
1253 len2 = GST_CAPS_LEN (caps2);
1254 for (i = 0; i < len1; i++) {
1255 struct1 = gst_caps_get_structure_unchecked (caps1, i);
1256 for (j = 0; j < len2; j++) {
1257 struct2 = gst_caps_get_structure_unchecked (caps2, j);
1258 istruct = gst_structure_intersect (struct1, struct2);
1260 gst_caps_merge_structure (dest, istruct);
1268 * gst_caps_intersect_full:
1269 * @caps1: a #GstCaps to intersect
1270 * @caps2: a #GstCaps to intersect
1271 * @mode: The intersection algorithm/mode to use
1273 * Creates a new #GstCaps that contains all the formats that are common
1274 * to both @caps1 and @caps2, the order is defined by the #GstCapsIntersectMode
1277 * Returns: the new #GstCaps
1281 gst_caps_intersect_full (const GstCaps * caps1, const GstCaps * caps2,
1282 GstCapsIntersectMode mode)
1284 g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
1285 g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
1288 case GST_CAPS_INTERSECT_FIRST:
1289 return gst_caps_intersect_first (caps1, caps2);
1291 g_warning ("Unknown caps intersect mode: %d", mode);
1293 case GST_CAPS_INTERSECT_ZIG_ZAG:
1294 return gst_caps_intersect_zig_zag (caps1, caps2);
1299 * gst_caps_intersect:
1300 * @caps1: a #GstCaps to intersect
1301 * @caps2: a #GstCaps to intersect
1303 * Creates a new #GstCaps that contains all the formats that are common
1304 * to both @caps1 and @caps2. Defaults to %GST_CAPS_INTERSECT_ZIG_ZAG mode.
1306 * Returns: the new #GstCaps
1309 gst_caps_intersect (const GstCaps * caps1, const GstCaps * caps2)
1311 return gst_caps_intersect_full (caps1, caps2, GST_CAPS_INTERSECT_ZIG_ZAG);
1315 /* subtract operation */
1319 const GstStructure *subtract_from;
1325 gst_caps_structure_subtract_field (GQuark field_id, const GValue * value,
1328 SubtractionEntry *e = user_data;
1329 GValue subtraction = { 0, };
1330 const GValue *other;
1331 GstStructure *structure;
1333 other = gst_structure_id_get_value (e->subtract_from, field_id);
1337 if (!gst_value_subtract (&subtraction, other, value))
1339 if (gst_value_compare (&subtraction, other) == GST_VALUE_EQUAL) {
1340 g_value_unset (&subtraction);
1343 structure = gst_structure_copy (e->subtract_from);
1344 gst_structure_id_set_value (structure, field_id, &subtraction);
1345 g_value_unset (&subtraction);
1346 e->put_into = g_slist_prepend (e->put_into, structure);
1352 gst_caps_structure_subtract (GSList ** into, const GstStructure * minuend,
1353 const GstStructure * subtrahend)
1358 e.subtract_from = minuend;
1361 ret = gst_structure_foreach ((GstStructure *) subtrahend,
1362 gst_caps_structure_subtract_field, &e);
1368 for (walk = e.put_into; walk; walk = g_slist_next (walk)) {
1369 gst_structure_free (walk->data);
1371 g_slist_free (e.put_into);
1377 * gst_caps_subtract:
1378 * @minuend: #GstCaps to subtract from
1379 * @subtrahend: #GstCaps to subtract
1381 * Subtracts the @subtrahend from the @minuend.
1382 * <note>This function does not work reliably if optional properties for caps
1383 * are included on one caps and omitted on the other.</note>
1385 * Returns: the resulting caps
1388 gst_caps_subtract (const GstCaps * minuend, const GstCaps * subtrahend)
1393 GstCaps *dest = NULL, *src;
1395 g_return_val_if_fail (minuend != NULL, NULL);
1396 g_return_val_if_fail (subtrahend != NULL, NULL);
1398 if (CAPS_IS_EMPTY (minuend) || CAPS_IS_ANY (subtrahend)) {
1399 return gst_caps_new_empty ();
1401 if (CAPS_IS_EMPTY_SIMPLE (subtrahend))
1402 return _gst_caps_copy (minuend);
1404 /* FIXME: Do we want this here or above?
1405 The reason we need this is that there is no definition about what
1406 ANY means for specific types, so it's not possible to reduce ANY partially
1407 You can only remove everything or nothing and that is done above.
1408 Note: there's a test that checks this behaviour. */
1409 g_return_val_if_fail (!CAPS_IS_ANY (minuend), NULL);
1410 sublen = GST_CAPS_LEN (subtrahend);
1411 g_assert (sublen > 0);
1413 src = _gst_caps_copy (minuend);
1414 for (i = 0; i < sublen; i++) {
1417 sub = gst_caps_get_structure_unchecked (subtrahend, i);
1419 gst_caps_unref (src);
1422 dest = gst_caps_new_empty ();
1423 srclen = GST_CAPS_LEN (src);
1424 for (j = 0; j < srclen; j++) {
1425 min = gst_caps_get_structure_unchecked (src, j);
1426 if (gst_structure_get_name_id (min) == gst_structure_get_name_id (sub)) {
1429 if (gst_caps_structure_subtract (&list, min, sub)) {
1432 for (walk = list; walk; walk = g_slist_next (walk)) {
1433 gst_caps_append_structure_unchecked (dest,
1434 (GstStructure *) walk->data);
1436 g_slist_free (list);
1438 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1441 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1444 if (CAPS_IS_EMPTY_SIMPLE (dest)) {
1445 gst_caps_unref (src);
1450 gst_caps_unref (src);
1451 gst_caps_do_simplify (dest);
1455 /* union operation */
1458 static GstStructure *
1459 gst_caps_structure_union (const GstStructure * struct1,
1460 const GstStructure * struct2)
1464 const GstStructureField *field1;
1465 const GstStructureField *field2;
1468 /* FIXME this doesn't actually work */
1470 if (struct1->name != struct2->name)
1473 dest = gst_structure_id_empty_new (struct1->name);
1475 for (i = 0; i < struct1->fields->len; i++) {
1476 GValue dest_value = { 0 };
1478 field1 = GST_STRUCTURE_FIELD (struct1, i);
1479 field2 = gst_structure_id_get_field (struct2, field1->name);
1481 if (field2 == NULL) {
1484 if (gst_value_union (&dest_value, &field1->value, &field2->value)) {
1485 gst_structure_set_value (dest, g_quark_to_string (field1->name),
1488 ret = gst_value_compare (&field1->value, &field2->value);
1499 * @caps1: a #GstCaps to union
1500 * @caps2: a #GstCaps to union
1502 * Creates a new #GstCaps that contains all the formats that are in
1503 * either @caps1 and @caps2.
1505 * Returns: the new #GstCaps
1508 gst_caps_union (const GstCaps * caps1, const GstCaps * caps2)
1513 /* NULL pointers are no correct GstCaps */
1514 g_return_val_if_fail (caps1 != NULL, NULL);
1515 g_return_val_if_fail (caps2 != NULL, NULL);
1517 if (CAPS_IS_EMPTY (caps1))
1518 return _gst_caps_copy (caps2);
1520 if (CAPS_IS_EMPTY (caps2))
1521 return _gst_caps_copy (caps1);
1523 if (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))
1524 return gst_caps_new_any ();
1526 dest1 = _gst_caps_copy (caps1);
1527 dest2 = _gst_caps_copy (caps2);
1528 gst_caps_append (dest1, dest2);
1530 gst_caps_do_simplify (dest1);
1534 /* normalize/simplify operations */
1536 typedef struct _NormalizeForeach
1539 GstStructure *structure;
1544 gst_caps_normalize_foreach (GQuark field_id, const GValue * value, gpointer ptr)
1546 NormalizeForeach *nf = (NormalizeForeach *) ptr;
1550 if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
1551 guint len = gst_value_list_get_size (value);
1552 for (i = 1; i < len; i++) {
1553 const GValue *v = gst_value_list_get_value (value, i);
1554 GstStructure *structure = gst_structure_copy (nf->structure);
1556 gst_structure_id_set_value (structure, field_id, v);
1557 gst_caps_append_structure_unchecked (nf->caps, structure);
1560 gst_value_init_and_copy (&val, gst_value_list_get_value (value, 0));
1561 gst_structure_id_set_value (nf->structure, field_id, &val);
1562 g_value_unset (&val);
1570 * gst_caps_normalize:
1571 * @caps: a #GstCaps to normalize
1573 * Creates a new #GstCaps that represents the same set of formats as
1574 * @caps, but contains no lists. Each list is expanded into separate
1577 * Returns: the new #GstCaps
1580 gst_caps_normalize (const GstCaps * caps)
1582 NormalizeForeach nf;
1586 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
1588 newcaps = _gst_caps_copy (caps);
1591 for (i = 0; i < gst_caps_get_size (newcaps); i++) {
1592 nf.structure = gst_caps_get_structure_unchecked (newcaps, i);
1594 while (!gst_structure_foreach (nf.structure,
1595 gst_caps_normalize_foreach, &nf));
1602 gst_caps_compare_structures (gconstpointer one, gconstpointer two)
1605 const GstStructure *struct1 = *((const GstStructure **) one);
1606 const GstStructure *struct2 = *((const GstStructure **) two);
1608 /* FIXME: this orders alphabetically, but ordering the quarks might be faster
1609 So what's the best way? */
1610 ret = strcmp (gst_structure_get_name (struct1),
1611 gst_structure_get_name (struct2));
1615 return gst_structure_n_fields (struct2) - gst_structure_n_fields (struct1);
1622 GstStructure *compare;
1627 gst_caps_structure_figure_out_union (GQuark field_id, const GValue * value,
1630 UnionField *u = user_data;
1631 const GValue *val = gst_structure_id_get_value (u->compare, field_id);
1635 g_value_unset (&u->value);
1638 if (gst_value_compare (val, value) == GST_VALUE_EQUAL)
1641 g_value_unset (&u->value);
1645 gst_value_union (&u->value, val, value);
1650 gst_caps_structure_simplify (GstStructure ** result,
1651 const GstStructure * simplify, GstStructure * compare)
1654 UnionField field = { 0, {0,}, NULL };
1656 /* try to subtract to get a real subset */
1657 if (gst_caps_structure_subtract (&list, simplify, compare)) {
1658 if (list == NULL) { /* no result */
1661 } else if (list->next == NULL) { /* one result */
1662 *result = list->data;
1663 g_slist_free (list);
1665 } else { /* multiple results */
1666 g_slist_foreach (list, (GFunc) gst_structure_free, NULL);
1667 g_slist_free (list);
1672 /* try to union both structs */
1673 field.compare = compare;
1674 if (gst_structure_foreach ((GstStructure *) simplify,
1675 gst_caps_structure_figure_out_union, &field)) {
1676 gboolean ret = FALSE;
1678 /* now we know all of simplify's fields are the same in compare
1679 * but at most one field: field.name */
1680 if (G_IS_VALUE (&field.value)) {
1681 if (gst_structure_n_fields (simplify) == gst_structure_n_fields (compare)) {
1682 gst_structure_id_set_value (compare, field.name, &field.value);
1686 g_value_unset (&field.value);
1687 } else if (gst_structure_n_fields (simplify) <=
1688 gst_structure_n_fields (compare)) {
1689 /* compare is just more specific, will be optimized away later */
1690 /* FIXME: do this here? */
1691 GST_LOG ("found a case that will be optimized later.");
1693 gchar *one = gst_structure_to_string (simplify);
1694 gchar *two = gst_structure_to_string (compare);
1697 ("caps mismatch: structures %s and %s claim to be possible to unify, but aren't",
1709 gst_caps_switch_structures (GstCaps * caps, GstStructure * old,
1710 GstStructure * new, gint i)
1712 gst_structure_set_parent_refcount (old, NULL);
1713 gst_structure_free (old);
1714 gst_structure_set_parent_refcount (new, &GST_CAPS_REFCOUNT (caps));
1715 g_ptr_array_index (GST_CAPS_ARRAY (caps), i) = new;
1719 * gst_caps_do_simplify:
1720 * @caps: a #GstCaps to simplify
1722 * Modifies the given @caps inplace into a representation that represents the
1723 * same set of formats, but in a simpler form. Component structures that are
1724 * identical are merged. Component structures that have values that can be
1725 * merged are also merged.
1727 * Returns: TRUE, if the caps could be simplified
1730 gst_caps_do_simplify (GstCaps * caps)
1732 GstStructure *simplify, *compare, *result = NULL;
1734 gboolean changed = FALSE;
1736 g_return_val_if_fail (caps != NULL, FALSE);
1737 g_return_val_if_fail (IS_WRITABLE (caps), FALSE);
1739 if (gst_caps_get_size (caps) < 2)
1742 g_ptr_array_sort (GST_CAPS_ARRAY (caps), gst_caps_compare_structures);
1744 start = GST_CAPS_LEN (caps) - 1;
1745 for (i = GST_CAPS_LEN (caps) - 1; i >= 0; i--) {
1746 simplify = gst_caps_get_structure_unchecked (caps, i);
1747 if (gst_structure_get_name_id (simplify) !=
1748 gst_structure_get_name_id (gst_caps_get_structure_unchecked (caps,
1751 for (j = start; j >= 0; j--) {
1754 compare = gst_caps_get_structure_unchecked (caps, j);
1755 if (gst_structure_get_name_id (simplify) !=
1756 gst_structure_get_name_id (compare)) {
1759 if (gst_caps_structure_simplify (&result, simplify, compare)) {
1761 gst_caps_switch_structures (caps, simplify, result, i);
1764 gst_caps_remove_structure (caps, i);
1776 /* gst_caps_do_simplify (caps); */
1782 * @caps: a #GstCaps to fixate
1784 * Modifies the given @caps inplace into a representation with only fixed
1785 * values. First the caps will be truncated and then the first structure will be
1786 * fixated with gst_structure_fixate(). @caps should be writable.
1789 gst_caps_fixate (GstCaps * caps)
1793 g_return_if_fail (GST_IS_CAPS (caps));
1794 g_return_if_fail (IS_WRITABLE (caps));
1796 /* default fixation */
1797 gst_caps_truncate (caps);
1798 s = gst_caps_get_structure (caps, 0);
1799 gst_structure_fixate (s);
1805 * gst_caps_to_string:
1808 * Converts @caps to a string representation. This string representation
1809 * can be converted back to a #GstCaps by gst_caps_from_string().
1811 * For debugging purposes its easier to do something like this:
1813 * GST_LOG ("caps are %" GST_PTR_FORMAT, caps);
1815 * This prints the caps in human readble form.
1817 * Returns: (transfer full): a newly allocated string representing @caps.
1820 gst_caps_to_string (const GstCaps * caps)
1822 guint i, slen, clen;
1825 /* NOTE: This function is potentially called by the debug system,
1826 * so any calls to gst_log() (and GST_DEBUG(), GST_LOG(), etc.)
1827 * should be careful to avoid recursion. This includes any functions
1828 * called by gst_caps_to_string. In particular, calls should
1829 * not use the GST_PTR_FORMAT extension. */
1832 return g_strdup ("NULL");
1834 if (CAPS_IS_ANY (caps)) {
1835 return g_strdup ("ANY");
1837 if (CAPS_IS_EMPTY_SIMPLE (caps)) {
1838 return g_strdup ("EMPTY");
1841 /* estimate a rough string length to avoid unnecessary reallocs in GString */
1843 clen = GST_CAPS_LEN (caps);
1844 for (i = 0; i < clen; i++) {
1846 STRUCTURE_ESTIMATED_STRING_LEN (gst_caps_get_structure_unchecked (caps,
1850 s = g_string_sized_new (slen);
1851 for (i = 0; i < clen; i++) {
1852 GstStructure *structure;
1855 /* ';' is now added by gst_structure_to_string */
1856 g_string_append_c (s, ' ');
1859 structure = gst_caps_get_structure_unchecked (caps, i);
1860 priv_gst_structure_append_to_gstring (structure, s);
1862 if (s->len && s->str[s->len - 1] == ';') {
1863 /* remove latest ';' */
1864 s->str[--s->len] = '\0';
1866 return g_string_free (s, FALSE);
1870 gst_caps_from_string_inplace (GstCaps * caps, const gchar * string)
1872 GstStructure *structure;
1875 if (strcmp ("ANY", string) == 0) {
1876 GST_CAPS_FLAGS (caps) = GST_CAPS_FLAGS_ANY;
1879 if (strcmp ("EMPTY", string) == 0) {
1883 structure = gst_structure_from_string (string, &s);
1884 if (structure == NULL) {
1887 gst_caps_append_structure_unchecked (caps, structure);
1891 while (g_ascii_isspace (*s))
1896 structure = gst_structure_from_string (s, &s);
1897 if (structure == NULL) {
1900 gst_caps_append_structure_unchecked (caps, structure);
1908 * gst_caps_from_string:
1909 * @string: a string to convert to #GstCaps
1911 * Converts @caps from a string representation.
1913 * Returns: (transfer full): a newly allocated #GstCaps
1916 gst_caps_from_string (const gchar * string)
1920 g_return_val_if_fail (string, FALSE);
1922 caps = gst_caps_new_empty ();
1923 if (gst_caps_from_string_inplace (caps, string)) {
1926 gst_caps_unref (caps);
1932 gst_caps_transform_to_string (const GValue * src_value, GValue * dest_value)
1934 g_return_if_fail (G_IS_VALUE (src_value));
1935 g_return_if_fail (G_IS_VALUE (dest_value));
1936 g_return_if_fail (G_VALUE_HOLDS (src_value, GST_TYPE_CAPS));
1937 g_return_if_fail (G_VALUE_HOLDS (dest_value, G_TYPE_STRING)
1938 || G_VALUE_HOLDS (dest_value, G_TYPE_POINTER));
1940 g_value_take_string (dest_value,
1941 gst_caps_to_string (gst_value_get_caps (src_value)));