2 * Copyright (C) <2003> David A. Schleef <ds@schleef.org>
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
14 * You should have received a copy of the GNU Library General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
22 * @short_description: Structure describing sets of media formats
23 * @see_also: #GstStructure
25 * Caps (capabilities) are lighweight refcounted objects describing media types.
26 * They are composed of an array of #GstStructure.
28 * Caps are exposed on #GstPadTemplate to describe all possible types a
29 * given pad can handle. They are also stored in the #GstRegistry along with
30 * a description of the #GstElement.
32 * Caps are exposed on the element pads using the gst_pad_get_caps() pad
33 * function. This function describes the possible types that the pad can
34 * handle or produce at runtime.
36 * Caps are also attached to buffers to describe to content of the data
37 * pointed to by the buffer with gst_buffer_set_caps(). Caps attached to
38 * a #GstBuffer allow for format negotiation upstream and downstream.
40 * A #GstCaps can be constructed with the following code fragment:
43 * <title>Creating caps</title>
46 * caps = gst_caps_new_simple ("video/x-raw-yuv",
47 * "format", GST_TYPE_FOURCC, GST_MAKE_FOURCC ('I', '4', '2', '0'),
48 * "framerate", GST_TYPE_FRACTION, 25, 1,
49 * "pixel-aspect-ratio", GST_TYPE_FRACTION, 1, 1,
50 * "width", G_TYPE_INT, 320,
51 * "height", G_TYPE_INT, 240,
56 * A #GstCaps is fixed when it has no properties with ranges or lists. Use
57 * gst_caps_is_fixed() to test for fixed caps. Only fixed caps can be
58 * set on a #GstPad or #GstBuffer.
60 * Various methods exist to work with the media types such as subtracting
63 * Last reviewed on 2007-02-13 (0.10.10)
72 #include "gst_private.h"
74 #include <gobject/gvaluecollector.h>
76 #define DEBUG_REFCOUNT
78 #define CAPS_POISON(caps) G_STMT_START{ \
80 GstCaps *_newcaps = gst_caps_copy (caps); \
81 gst_caps_unref(caps); \
85 #define STRUCTURE_POISON(structure) G_STMT_START{ \
87 GstStructure *_newstruct = gst_structure_copy (structure); \
88 gst_structure_free(structure); \
89 structure = _newstruct; \
92 #define IS_WRITABLE(caps) \
93 (g_atomic_int_get (&(caps)->refcount) == 1)
95 /* quick way to get a caps structure at an index without doing a type or array
97 #define gst_caps_get_structure_unchecked(caps, index) \
98 ((GstStructure *)g_ptr_array_index ((caps)->structs, (index)))
101 /* lock to protect multiple invocations of static caps to caps conversion */
102 G_LOCK_DEFINE_STATIC (static_caps_lock);
104 static void gst_caps_transform_to_string (const GValue * src_value,
105 GValue * dest_value);
106 static gboolean gst_caps_from_string_inplace (GstCaps * caps,
107 const gchar * string);
108 static GstCaps *gst_caps_copy_conditional (GstCaps * src);
111 gst_caps_get_type (void)
113 static GType gst_caps_type = 0;
115 if (G_UNLIKELY (gst_caps_type == 0)) {
116 gst_caps_type = g_boxed_type_register_static ("GstCaps",
117 (GBoxedCopyFunc) gst_caps_copy_conditional,
118 (GBoxedFreeFunc) gst_caps_unref);
120 g_value_register_transform_func (gst_caps_type,
121 G_TYPE_STRING, gst_caps_transform_to_string);
124 return gst_caps_type;
127 /* creation/deletion */
130 * gst_caps_new_empty:
132 * Creates a new #GstCaps that is empty. That is, the returned
133 * #GstCaps contains no media formats.
134 * Caller is responsible for unreffing the returned caps.
136 * Returns: the new #GstCaps
139 gst_caps_new_empty (void)
141 GstCaps *caps = g_slice_new (GstCaps);
143 caps->type = GST_TYPE_CAPS;
146 caps->structs = g_ptr_array_new ();
147 /* the 32 has been determined by logging caps sizes in _gst_caps_free
148 * but g_ptr_array uses 16 anyway if it expands once, so this does not help
150 * caps->structs = g_ptr_array_sized_new (32);
153 #ifdef DEBUG_REFCOUNT
154 GST_CAT_LOG (GST_CAT_CAPS, "created caps %p", caps);
163 * Creates a new #GstCaps that indicates that it is compatible with
166 * Returns: the new #GstCaps
169 gst_caps_new_any (void)
171 GstCaps *caps = gst_caps_new_empty ();
173 caps->flags = GST_CAPS_FLAGS_ANY;
179 * gst_caps_new_simple:
180 * @media_type: the media type of the structure
181 * @fieldname: first field to set
182 * @...: additional arguments
184 * Creates a new #GstCaps that contains one #GstStructure. The
185 * structure is defined by the arguments, which have the same format
186 * as gst_structure_new().
187 * Caller is responsible for unreffing the returned caps.
189 * Returns: the new #GstCaps
192 gst_caps_new_simple (const char *media_type, const char *fieldname, ...)
195 GstStructure *structure;
198 caps = gst_caps_new_empty ();
200 va_start (var_args, fieldname);
201 structure = gst_structure_new_valist (media_type, fieldname, var_args);
204 gst_caps_append_structure (caps, structure);
211 * @struct1: the first structure to add
212 * @...: additional structures to add
214 * Creates a new #GstCaps and adds all the structures listed as
215 * arguments. The list must be NULL-terminated. The structures
216 * are not copied; the returned #GstCaps owns the structures.
218 * Returns: the new #GstCaps
221 gst_caps_new_full (GstStructure * struct1, ...)
226 va_start (var_args, struct1);
227 caps = gst_caps_new_full_valist (struct1, var_args);
234 * gst_caps_new_full_valist:
235 * @structure: the first structure to add
236 * @var_args: additional structures to add
238 * Creates a new #GstCaps and adds all the structures listed as
239 * arguments. The list must be NULL-terminated. The structures
240 * are not copied; the returned #GstCaps owns the structures.
242 * Returns: the new #GstCaps
245 gst_caps_new_full_valist (GstStructure * structure, va_list var_args)
249 caps = gst_caps_new_empty ();
252 gst_caps_append_structure (caps, structure);
253 structure = va_arg (var_args, GstStructure *);
261 * @caps: the #GstCaps to copy
263 * Creates a new #GstCaps as a copy of the old @caps. The new caps will have a
264 * refcount of 1, owned by the caller. The structures are copied as well.
266 * Note that this function is the semantic equivalent of a gst_caps_ref()
267 * followed by a gst_caps_make_writable(). If you only want to hold on to a
268 * reference to the data, you should use gst_caps_ref().
270 * When you are finished with the caps, call gst_caps_unref() on it.
272 * Returns: the new #GstCaps
275 gst_caps_copy (const GstCaps * caps)
278 GstStructure *structure;
281 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
283 newcaps = gst_caps_new_empty ();
284 newcaps->flags = caps->flags;
285 n = caps->structs->len;
287 for (i = 0; i < n; i++) {
288 structure = gst_caps_get_structure_unchecked (caps, i);
289 gst_caps_append_structure (newcaps, gst_structure_copy (structure));
296 _gst_caps_free (GstCaps * caps)
298 GstStructure *structure;
301 /* The refcount must be 0, but since we're only called by gst_caps_unref,
302 * don't bother testing. */
303 len = caps->structs->len;
304 /* This can be used to get statistics about caps sizes */
305 /*GST_CAT_INFO (GST_CAT_CAPS, "caps size: %d", len); */
306 for (i = 0; i < len; i++) {
307 structure = (GstStructure *) gst_caps_get_structure_unchecked (caps, i);
308 gst_structure_set_parent_refcount (structure, NULL);
309 gst_structure_free (structure);
311 g_ptr_array_free (caps->structs, TRUE);
313 memset (caps, 0xff, sizeof (GstCaps));
316 #ifdef DEBUG_REFCOUNT
317 GST_CAT_LOG (GST_CAT_CAPS, "freeing caps %p", caps);
319 g_slice_free (GstCaps, caps);
323 * gst_caps_make_writable:
324 * @caps: the #GstCaps to make writable
326 * Returns a writable copy of @caps.
328 * If there is only one reference count on @caps, the caller must be the owner,
329 * and so this function will return the caps object unchanged. If on the other
330 * hand there is more than one reference on the object, a new caps object will
331 * be returned. The caller's reference on @caps will be removed, and instead the
332 * caller will own a reference to the returned object.
334 * In short, this function unrefs the caps in the argument and refs the caps
335 * that it returns. Don't access the argument after calling this function. See
336 * also: gst_caps_ref().
338 * Returns: the same #GstCaps object.
341 gst_caps_make_writable (GstCaps * caps)
345 g_return_val_if_fail (caps != NULL, NULL);
347 /* we are the only instance reffing this caps */
348 if (g_atomic_int_get (&caps->refcount) == 1)
352 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy caps");
353 copy = gst_caps_copy (caps);
354 gst_caps_unref (caps);
361 * @caps: the #GstCaps to reference
363 * Add a reference to a #GstCaps object.
365 * From this point on, until the caller calls gst_caps_unref() or
366 * gst_caps_make_writable(), it is guaranteed that the caps object will not
367 * change. This means its structures won't change, etc. To use a #GstCaps
368 * object, you must always have a refcount on it -- either the one made
369 * implicitly by gst_caps_new(), or via taking one explicitly with this
372 * Returns: the same #GstCaps object.
375 gst_caps_ref (GstCaps * caps)
377 g_return_val_if_fail (caps != NULL, NULL);
379 #ifdef DEBUG_REFCOUNT
380 GST_CAT_LOG (GST_CAT_REFCOUNTING, "%p %d->%d", caps,
381 GST_CAPS_REFCOUNT_VALUE (caps), GST_CAPS_REFCOUNT_VALUE (caps) + 1);
383 g_return_val_if_fail (GST_CAPS_REFCOUNT_VALUE (caps) > 0, NULL);
385 g_atomic_int_inc (&caps->refcount);
392 * @caps: the #GstCaps to unref
394 * Unref a #GstCaps and and free all its structures and the
395 * structures' values when the refcount reaches 0.
398 gst_caps_unref (GstCaps * caps)
400 g_return_if_fail (caps != NULL);
402 #ifdef DEBUG_REFCOUNT
403 GST_CAT_LOG (GST_CAT_REFCOUNTING, "%p %d->%d", caps,
404 GST_CAPS_REFCOUNT_VALUE (caps), GST_CAPS_REFCOUNT_VALUE (caps) - 1);
407 g_return_if_fail (GST_CAPS_REFCOUNT_VALUE (caps) > 0);
409 /* if we ended up with the refcount at zero, free the caps */
410 if (G_UNLIKELY (g_atomic_int_dec_and_test (&caps->refcount)))
411 _gst_caps_free (caps);
415 gst_static_caps_get_type (void)
417 static GType staticcaps_type = 0;
419 if (G_UNLIKELY (staticcaps_type == 0)) {
420 staticcaps_type = g_pointer_type_register_static ("GstStaticCaps");
422 return staticcaps_type;
427 * gst_static_caps_get:
428 * @static_caps: the #GstStaticCaps to convert
430 * Converts a #GstStaticCaps to a #GstCaps.
432 * Returns: A pointer to the #GstCaps. Unref after usage. Since the
433 * core holds an additional ref to the returned caps,
434 * use gst_caps_make_writable() on the returned caps to modify it.
437 gst_static_caps_get (GstStaticCaps * static_caps)
441 g_return_val_if_fail (static_caps != NULL, NULL);
443 caps = (GstCaps *) static_caps;
445 /* refcount is 0 when we need to convert */
446 if (G_UNLIKELY (g_atomic_int_get (&caps->refcount) == 0)) {
450 G_LOCK (static_caps_lock);
451 /* check if other thread already updated */
452 if (G_UNLIKELY (g_atomic_int_get (&caps->refcount) > 0))
455 string = static_caps->string;
457 if (G_UNLIKELY (string == NULL))
460 GST_CAT_LOG (GST_CAT_CAPS, "creating %p", static_caps);
462 /* we construct the caps on the stack, then copy over the struct into our
463 * real caps, refcount last. We do this because we must leave the refcount
464 * of the result caps to 0 so that other threads don't run away with the
465 * caps while we are constructing it. */
466 temp.type = GST_TYPE_CAPS;
468 temp.structs = g_ptr_array_new ();
470 /* initialize the caps to a refcount of 1 so the caps can be writable for
471 * the next statement */
474 /* convert to string */
475 if (G_UNLIKELY (!gst_caps_from_string_inplace (&temp, string)))
476 g_critical ("Could not convert static caps \"%s\"", string);
478 /* now copy stuff over to the real caps. */
479 caps->type = temp.type;
480 caps->flags = temp.flags;
481 caps->structs = temp.structs;
482 /* and bump the refcount so other threads can now read */
483 g_atomic_int_set (&caps->refcount, 1);
485 GST_CAT_LOG (GST_CAT_CAPS, "created %p", static_caps);
487 G_UNLOCK (static_caps_lock);
489 /* ref the caps, makes it not writable */
497 G_UNLOCK (static_caps_lock);
498 g_warning ("static caps %p string is NULL", static_caps);
504 static GstStructure *
505 gst_caps_remove_and_get_structure (GstCaps * caps, guint idx)
507 /* don't use index_fast, gst_caps_do_simplify relies on the order */
508 GstStructure *s = g_ptr_array_remove_index (caps->structs, idx);
510 gst_structure_set_parent_refcount (s, NULL);
515 gst_structure_is_equal_foreach (GQuark field_id, const GValue * val2,
518 GstStructure *struct1 = (GstStructure *) data;
519 const GValue *val1 = gst_structure_id_get_value (struct1, field_id);
521 if (G_UNLIKELY (val1 == NULL))
523 if (gst_value_compare (val1, val2) == GST_VALUE_EQUAL) {
531 gst_caps_structure_is_subset_field (GQuark field_id, const GValue * value,
534 GstStructure *subtract_from = user_data;
535 GValue subtraction = { 0, };
538 if (!(other = gst_structure_id_get_value (subtract_from, field_id)))
539 /* field is missing in one set */
542 /* equal values are subset */
543 if (gst_value_compare (other, value) == GST_VALUE_EQUAL)
551 * -> 1 - [1,2] = empty
555 * -> [1,2] - [1,3] = empty
559 * -> {1,3} - {1,2} = 3
562 * First caps subtraction needs to return a non-empty set, second
563 * subtractions needs to give en empty set.
565 if (gst_value_subtract (&subtraction, other, value)) {
566 g_value_unset (&subtraction);
567 /* !empty result, swapping must be empty */
568 if (!gst_value_subtract (&subtraction, value, other))
571 g_value_unset (&subtraction);
577 gst_caps_structure_is_subset (const GstStructure * minuend,
578 const GstStructure * subtrahend)
580 if ((minuend->name != subtrahend->name) ||
581 (gst_structure_n_fields (minuend) !=
582 gst_structure_n_fields (subtrahend))) {
586 return gst_structure_foreach ((GstStructure *) subtrahend,
587 gst_caps_structure_is_subset_field, (gpointer) minuend);
592 * @caps1: the #GstCaps that will be appended to
593 * @caps2: the #GstCaps to append
595 * Appends the structures contained in @caps2 to @caps1. The structures in
596 * @caps2 are not copied -- they are transferred to @caps1, and then @caps2 is
597 * freed. If either caps is ANY, the resulting caps will be ANY.
600 gst_caps_append (GstCaps * caps1, GstCaps * caps2)
602 GstStructure *structure;
605 g_return_if_fail (GST_IS_CAPS (caps1));
606 g_return_if_fail (GST_IS_CAPS (caps2));
607 g_return_if_fail (IS_WRITABLE (caps1));
608 g_return_if_fail (IS_WRITABLE (caps2));
613 if (G_UNLIKELY (gst_caps_is_any (caps1) || gst_caps_is_any (caps2))) {
614 /* FIXME: this leaks */
615 caps1->flags |= GST_CAPS_FLAGS_ANY;
616 for (i = caps2->structs->len - 1; i >= 0; i--) {
617 structure = gst_caps_remove_and_get_structure (caps2, i);
618 gst_structure_free (structure);
621 for (i = caps2->structs->len; i; i--) {
622 structure = gst_caps_remove_and_get_structure (caps2, 0);
623 gst_caps_append_structure (caps1, structure);
626 gst_caps_unref (caps2); /* guaranteed to free it */
631 * @caps1: the #GstCaps that will take the new entries
632 * @caps2: the #GstCaps to merge in
634 * Appends the structures contained in @caps2 to @caps1 if they are not yet
635 * expressed by @caps1. The structures in @caps2 are not copied -- they are
636 * transferred to @caps1, and then @caps2 is freed.
637 * If either caps is ANY, the resulting caps will be ANY.
642 gst_caps_merge (GstCaps * caps1, GstCaps * caps2)
644 GstStructure *structure;
647 g_return_if_fail (GST_IS_CAPS (caps1));
648 g_return_if_fail (GST_IS_CAPS (caps2));
649 g_return_if_fail (IS_WRITABLE (caps1));
650 g_return_if_fail (IS_WRITABLE (caps2));
655 if (G_UNLIKELY (gst_caps_is_any (caps1))) {
656 for (i = caps2->structs->len - 1; i >= 0; i--) {
657 structure = gst_caps_remove_and_get_structure (caps2, i);
658 gst_structure_free (structure);
660 } else if (G_UNLIKELY (gst_caps_is_any (caps2))) {
661 caps1->flags |= GST_CAPS_FLAGS_ANY;
662 for (i = caps1->structs->len - 1; i >= 0; i--) {
663 structure = gst_caps_remove_and_get_structure (caps1, i);
664 gst_structure_free (structure);
667 for (i = caps2->structs->len; i; i--) {
668 structure = gst_caps_remove_and_get_structure (caps2, 0);
669 gst_caps_merge_structure (caps1, structure);
672 GstCaps *com = gst_caps_intersect (caps1, caps2);
673 GstCaps *add = gst_caps_subtract (caps2, com);
675 GST_DEBUG ("common : %d", gst_caps_get_size (com));
676 GST_DEBUG ("adding : %d", gst_caps_get_size (add));
677 gst_caps_append (caps1, add);
678 gst_caps_unref (com);
681 gst_caps_unref (caps2); /* guaranteed to free it */
685 * gst_caps_append_structure:
686 * @caps: the #GstCaps that will be appended to
687 * @structure: the #GstStructure to append
689 * Appends @structure to @caps. The structure is not copied; @caps
690 * becomes the owner of @structure.
693 gst_caps_append_structure (GstCaps * caps, GstStructure * structure)
695 g_return_if_fail (GST_IS_CAPS (caps));
696 g_return_if_fail (IS_WRITABLE (caps));
698 if (G_LIKELY (structure)) {
699 g_return_if_fail (structure->parent_refcount == NULL);
702 STRUCTURE_POISON (structure);
705 gst_structure_set_parent_refcount (structure, &caps->refcount);
706 g_ptr_array_add (caps->structs, structure);
711 * gst_caps_remove_structure:
712 * @caps: the #GstCaps to remove from
713 * @idx: Index of the structure to remove
715 * removes the stucture with the given index from the list of structures
716 * contained in @caps.
719 gst_caps_remove_structure (GstCaps * caps, guint idx)
721 GstStructure *structure;
723 g_return_if_fail (caps != NULL);
724 g_return_if_fail (idx <= gst_caps_get_size (caps));
725 g_return_if_fail (IS_WRITABLE (caps));
727 structure = gst_caps_remove_and_get_structure (caps, idx);
728 gst_structure_free (structure);
732 * gst_caps_merge_structure:
733 * @caps: the #GstCaps that will the the new structure
734 * @structure: the #GstStructure to merge
736 * Appends @structure to @caps if its not already expressed by @caps. The
737 * structure is not copied; @caps becomes the owner of @structure.
740 gst_caps_merge_structure (GstCaps * caps, GstStructure * structure)
742 g_return_if_fail (GST_IS_CAPS (caps));
743 g_return_if_fail (IS_WRITABLE (caps));
745 if (G_LIKELY (structure)) {
746 GstStructure *structure1;
748 gboolean unique = TRUE;
750 g_return_if_fail (structure->parent_refcount == NULL);
753 STRUCTURE_POISON (structure);
756 /* check each structure */
757 for (i = caps->structs->len - 1; i >= 0; i--) {
758 structure1 = gst_caps_get_structure_unchecked (caps, i);
759 /* if structure is a subset of structure1, then skip it */
760 if (gst_caps_structure_is_subset (structure1, structure)) {
766 gst_structure_set_parent_refcount (structure, &caps->refcount);
767 g_ptr_array_add (caps->structs, structure);
769 gst_structure_free (structure);
779 * Gets the number of structures contained in @caps.
781 * Returns: the number of structures that @caps contains
784 gst_caps_get_size (const GstCaps * caps)
786 g_return_val_if_fail (GST_IS_CAPS (caps), 0);
788 return caps->structs->len;
792 * gst_caps_get_structure:
794 * @index: the index of the structure
796 * Finds the structure in @caps that has the index @index, and
799 * WARNING: This function takes a const GstCaps *, but returns a
800 * non-const GstStructure *. This is for programming convenience --
801 * the caller should be aware that structures inside a constant
802 * #GstCaps should not be modified. However, if you know the caps
803 * are writable, either because you have just copied them or made
804 * them writable with gst_caps_make_writable(), you may modify the
805 * structure returned in the usual way, e.g. with functions like
806 * gst_structure_set_simple().
808 * You do not need to free or unref the structure returned, it
809 * belongs to the #GstCaps.
811 * Returns: a pointer to the #GstStructure corresponding to @index
814 gst_caps_get_structure (const GstCaps * caps, guint index)
816 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
817 g_return_val_if_fail (index < caps->structs->len, NULL);
819 return gst_caps_get_structure_unchecked (caps, index);
824 * @caps: the #GstCaps to copy
825 * @nth: the nth structure to copy
827 * Creates a new #GstCaps and appends a copy of the nth structure
828 * contained in @caps.
830 * Returns: the new #GstCaps
833 gst_caps_copy_nth (const GstCaps * caps, guint nth)
836 GstStructure *structure;
838 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
840 newcaps = gst_caps_new_empty ();
841 newcaps->flags = caps->flags;
843 if (G_LIKELY (caps->structs->len > nth)) {
844 structure = gst_caps_get_structure_unchecked (caps, nth);
845 gst_caps_append_structure (newcaps, gst_structure_copy (structure));
853 * @caps: the #GstCaps to truncate
855 * Destructively discard all but the first structure from @caps. Useful when
856 * fixating. @caps must be writable.
859 gst_caps_truncate (GstCaps * caps)
863 g_return_if_fail (GST_IS_CAPS (caps));
864 g_return_if_fail (IS_WRITABLE (caps));
866 i = caps->structs->len - 1;
869 gst_caps_remove_structure (caps, i--);
873 * gst_caps_set_value:
874 * @caps: a writable caps
875 * @field: name of the field to set
876 * @value: value to set the field to
878 * Sets the given @field on all structures of @caps to the given @value.
879 * This is a convenience function for calling gst_structure_set_value() on
880 * all structures of @caps.
885 gst_caps_set_value (GstCaps * caps, const char *field, const GValue * value)
889 g_return_if_fail (GST_IS_CAPS (caps));
890 g_return_if_fail (IS_WRITABLE (caps));
891 g_return_if_fail (field != NULL);
892 g_return_if_fail (G_IS_VALUE (value));
894 len = caps->structs->len;
895 for (i = 0; i < len; i++) {
896 GstStructure *structure = gst_caps_get_structure_unchecked (caps, i);
897 gst_structure_set_value (structure, field, value);
902 * gst_caps_set_simple_valist:
903 * @caps: the #GstCaps to set
904 * @field: first field to set
905 * @varargs: additional parameters
907 * Sets fields in a #GstCaps. The arguments must be passed in the same
908 * manner as gst_structure_set(), and be NULL-terminated.
909 * <note>Prior to GStreamer version 0.10.26, this function failed when
910 * @caps was simple. If your code needs to work with those versions of
911 * GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
912 * is %TRUE for @caps.</note>
915 gst_caps_set_simple_valist (GstCaps * caps, const char *field, va_list varargs)
917 GValue value = { 0, };
919 g_return_if_fail (GST_IS_CAPS (caps));
920 g_return_if_fail (IS_WRITABLE (caps));
926 type = va_arg (varargs, GType);
928 if (G_UNLIKELY (type == G_TYPE_DATE)) {
929 g_warning ("Don't use G_TYPE_DATE, use GST_TYPE_DATE instead\n");
930 type = GST_TYPE_DATE;
933 g_value_init (&value, type);
934 G_VALUE_COLLECT (&value, varargs, 0, &err);
935 if (G_UNLIKELY (err)) {
936 g_critical ("%s", err);
940 gst_caps_set_value (caps, field, &value);
942 g_value_unset (&value);
944 field = va_arg (varargs, const gchar *);
949 * gst_caps_set_simple:
950 * @caps: the #GstCaps to set
951 * @field: first field to set
952 * @...: additional parameters
954 * Sets fields in a #GstCaps. The arguments must be passed in the same
955 * manner as gst_structure_set(), and be NULL-terminated.
956 * <note>Prior to GStreamer version 0.10.26, this function failed when
957 * @caps was simple. If your code needs to work with those versions of
958 * GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
959 * is %TRUE for @caps.</note>
962 gst_caps_set_simple (GstCaps * caps, const char *field, ...)
966 g_return_if_fail (GST_IS_CAPS (caps));
967 g_return_if_fail (IS_WRITABLE (caps));
969 va_start (var_args, field);
970 gst_caps_set_simple_valist (caps, field, var_args);
978 * @caps: the #GstCaps to test
980 * Determines if @caps represents any media format.
982 * Returns: TRUE if @caps represents any format.
985 gst_caps_is_any (const GstCaps * caps)
987 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
989 return (caps->flags & GST_CAPS_FLAGS_ANY);
994 * @caps: the #GstCaps to test
996 * Determines if @caps represents no media formats.
998 * Returns: TRUE if @caps represents no formats.
1001 gst_caps_is_empty (const GstCaps * caps)
1003 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1005 if (caps->flags & GST_CAPS_FLAGS_ANY)
1008 return (caps->structs == NULL) || (caps->structs->len == 0);
1012 gst_caps_is_fixed_foreach (GQuark field_id, const GValue * value,
1015 return gst_value_is_fixed (value);
1019 * gst_caps_is_fixed:
1020 * @caps: the #GstCaps to test
1022 * Fixed #GstCaps describe exactly one format, that is, they have exactly
1023 * one structure, and each field in the structure describes a fixed type.
1024 * Examples of non-fixed types are GST_TYPE_INT_RANGE and GST_TYPE_LIST.
1026 * Returns: TRUE if @caps is fixed
1029 gst_caps_is_fixed (const GstCaps * caps)
1031 GstStructure *structure;
1033 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1035 if (caps->structs->len != 1)
1038 structure = gst_caps_get_structure_unchecked (caps, 0);
1040 return gst_structure_foreach (structure, gst_caps_is_fixed_foreach, NULL);
1044 * gst_caps_is_equal_fixed:
1045 * @caps1: the #GstCaps to test
1046 * @caps2: the #GstCaps to test
1048 * Tests if two #GstCaps are equal. This function only works on fixed
1051 * Returns: TRUE if the arguments represent the same format
1054 gst_caps_is_equal_fixed (const GstCaps * caps1, const GstCaps * caps2)
1056 GstStructure *struct1, *struct2;
1058 g_return_val_if_fail (gst_caps_is_fixed (caps1), FALSE);
1059 g_return_val_if_fail (gst_caps_is_fixed (caps2), FALSE);
1061 struct1 = gst_caps_get_structure_unchecked (caps1, 0);
1062 struct2 = gst_caps_get_structure_unchecked (caps2, 0);
1064 if (struct1->name != struct2->name) {
1067 if (struct1->fields->len != struct2->fields->len) {
1071 return gst_structure_foreach (struct1, gst_structure_is_equal_foreach,
1076 * gst_caps_is_always_compatible:
1077 * @caps1: the #GstCaps to test
1078 * @caps2: the #GstCaps to test
1080 * A given #GstCaps structure is always compatible with another if
1081 * every media format that is in the first is also contained in the
1082 * second. That is, @caps1 is a subset of @caps2.
1084 * Returns: TRUE if @caps1 is a subset of @caps2.
1087 gst_caps_is_always_compatible (const GstCaps * caps1, const GstCaps * caps2)
1089 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1090 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1092 return gst_caps_is_subset (caps1, caps2);
1096 * gst_caps_is_subset:
1097 * @subset: a #GstCaps
1098 * @superset: a potentially greater #GstCaps
1100 * Checks if all caps represented by @subset are also represented by @superset.
1101 * <note>This function does not work reliably if optional properties for caps
1102 * are included on one caps and omitted on the other.</note>
1104 * Returns: %TRUE if @subset is a subset of @superset
1107 gst_caps_is_subset (const GstCaps * subset, const GstCaps * superset)
1112 g_return_val_if_fail (subset != NULL, FALSE);
1113 g_return_val_if_fail (superset != NULL, FALSE);
1115 if (gst_caps_is_empty (subset) || gst_caps_is_any (superset))
1117 if (gst_caps_is_any (subset) || gst_caps_is_empty (superset))
1120 caps = gst_caps_subtract (subset, superset);
1121 ret = gst_caps_is_empty (caps);
1122 gst_caps_unref (caps);
1127 * gst_caps_is_equal:
1128 * @caps1: a #GstCaps
1129 * @caps2: another #GstCaps
1131 * Checks if the given caps represent the same set of caps.
1132 * <note>This function does not work reliably if optional properties for caps
1133 * are included on one caps and omitted on the other.</note>
1135 * This function deals correctly with passing NULL for any of the caps.
1137 * Returns: TRUE if both caps are equal.
1140 gst_caps_is_equal (const GstCaps * caps1, const GstCaps * caps2)
1142 /* FIXME 0.11: NULL pointers are no valid Caps but indicate an error
1143 * So there should be an assertion that caps1 and caps2 != NULL */
1145 /* NULL <-> NULL is allowed here */
1146 if (G_UNLIKELY (caps1 == caps2))
1149 /* one of them NULL => they are different (can't be both NULL because
1150 * we checked that above) */
1151 if (G_UNLIKELY (caps1 == NULL || caps2 == NULL))
1154 if (G_UNLIKELY (gst_caps_is_fixed (caps1) && gst_caps_is_fixed (caps2)))
1155 return gst_caps_is_equal_fixed (caps1, caps2);
1157 return gst_caps_is_subset (caps1, caps2) && gst_caps_is_subset (caps2, caps1);
1163 const GstStructure *intersect;
1168 gst_caps_structure_intersect_field1 (GQuark id, const GValue * val1,
1171 IntersectData *idata = (IntersectData *) data;
1172 const GValue *val2 = gst_structure_id_get_value (idata->intersect, id);
1174 if (G_UNLIKELY (val2 == NULL)) {
1175 gst_structure_id_set_value (idata->dest, id, val1);
1177 GValue dest_value = { 0 };
1178 if (gst_value_intersect (&dest_value, val1, val2)) {
1179 gst_structure_id_set_value (idata->dest, id, &dest_value);
1180 g_value_unset (&dest_value);
1189 gst_caps_structure_intersect_field2 (GQuark id, const GValue * val1,
1192 IntersectData *idata = (IntersectData *) data;
1193 const GValue *val2 = gst_structure_id_get_value (idata->intersect, id);
1195 if (G_UNLIKELY (val2 == NULL)) {
1196 gst_structure_id_set_value (idata->dest, id, val1);
1201 static GstStructure *
1202 gst_caps_structure_intersect (const GstStructure * struct1,
1203 const GstStructure * struct2)
1207 g_return_val_if_fail (struct1 != NULL, NULL);
1208 g_return_val_if_fail (struct2 != NULL, NULL);
1210 if (G_UNLIKELY (struct1->name != struct2->name))
1213 /* copy fields from struct1 which we have not in struct2 to target
1214 * intersect if we have the field in both */
1215 data.dest = gst_structure_id_empty_new (struct1->name);
1216 data.intersect = struct2;
1217 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct1,
1218 gst_caps_structure_intersect_field1, &data)))
1221 /* copy fields from struct2 which we have not in struct1 to target */
1222 data.intersect = struct1;
1223 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct2,
1224 gst_caps_structure_intersect_field2, &data)))
1230 gst_structure_free (data.dest);
1235 gst_caps_structure_can_intersect_field (GQuark id, const GValue * val1,
1238 GstStructure *other = (GstStructure *) data;
1239 const GValue *val2 = gst_structure_id_get_value (other, id);
1241 if (G_LIKELY (val2)) {
1242 if (!gst_value_can_intersect (val1, val2)) {
1245 gint eq = gst_value_compare (val1, val2);
1247 if (eq == GST_VALUE_UNORDERED) {
1248 /* we need to try interseting */
1249 GValue dest_value = { 0 };
1250 if (gst_value_intersect (&dest_value, val1, val2)) {
1251 g_value_unset (&dest_value);
1255 } else if (eq != GST_VALUE_EQUAL) {
1264 gst_caps_structure_can_intersect (const GstStructure * struct1,
1265 const GstStructure * struct2)
1267 g_return_val_if_fail (struct1 != NULL, FALSE);
1268 g_return_val_if_fail (struct2 != NULL, FALSE);
1270 if (G_UNLIKELY (struct1->name != struct2->name))
1273 /* tries to intersect if we have the field in both */
1274 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct1,
1275 gst_caps_structure_can_intersect_field, (gpointer) struct2)))
1282 * gst_caps_can_intersect:
1283 * @caps1: a #GstCaps to intersect
1284 * @caps2: a #GstCaps to intersect
1286 * Tries intersecting @caps1 and @caps2 and reports wheter the result would not
1289 * Returns: %TRUE if intersection would be not empty
1294 gst_caps_can_intersect (const GstCaps * caps1, const GstCaps * caps2)
1296 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1297 guint j, k, len1, len2;
1298 GstStructure *struct1;
1299 GstStructure *struct2;
1301 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1302 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1304 /* caps are exactly the same pointers */
1305 if (G_UNLIKELY (caps1 == caps2))
1308 /* empty caps on either side, return empty */
1309 if (G_UNLIKELY (gst_caps_is_empty (caps1) || gst_caps_is_empty (caps2)))
1312 /* one of the caps is any */
1313 if (G_UNLIKELY (gst_caps_is_any (caps1) || gst_caps_is_any (caps2)))
1316 /* run zigzag on top line then right line, this preserves the caps order
1317 * much better than a simple loop.
1319 * This algorithm zigzags over the caps structures as demonstrated in
1320 * the folowing matrix:
1328 * First we iterate over the caps1 structures (top line) intersecting
1329 * the structures diagonally down, then we iterate over the caps2
1332 len1 = caps1->structs->len;
1333 len2 = caps2->structs->len;
1334 for (i = 0; i < len1 + len2 - 1; i++) {
1335 /* superset index goes from 0 to sgst_caps_structure_intersectuperset->structs->len-1 */
1336 j = MIN (i, len1 - 1);
1337 /* subset index stays 0 until i reaches superset->structs->len, then it
1338 * counts up from 1 to subset->structs->len - 1 */
1341 /* now run the diagonal line, end condition is the left or bottom
1344 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1345 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1347 if (gst_caps_structure_can_intersect (struct1, struct2)) {
1350 /* move down left */
1352 if (G_UNLIKELY (j == 0))
1353 break; /* so we don't roll back to G_MAXUINT */
1361 static GstStructure *
1362 gst_caps_structure_union (const GstStructure * struct1,
1363 const GstStructure * struct2)
1367 const GstStructureField *field1;
1368 const GstStructureField *field2;
1371 /* FIXME this doesn't actually work */
1373 if (struct1->name != struct2->name)
1376 dest = gst_structure_id_empty_new (struct1->name);
1378 for (i = 0; i < struct1->fields->len; i++) {
1379 GValue dest_value = { 0 };
1381 field1 = GST_STRUCTURE_FIELD (struct1, i);
1382 field2 = gst_structure_id_get_field (struct2, field1->name);
1384 if (field2 == NULL) {
1387 if (gst_value_union (&dest_value, &field1->value, &field2->value)) {
1388 gst_structure_set_value (dest, g_quark_to_string (field1->name),
1391 ret = gst_value_compare (&field1->value, &field2->value);
1403 * gst_caps_intersect:
1404 * @caps1: a #GstCaps to intersect
1405 * @caps2: a #GstCaps to intersect
1407 * Creates a new #GstCaps that contains all the formats that are common
1408 * to both @caps1 and @caps2.
1410 * Returns: the new #GstCaps
1413 gst_caps_intersect (const GstCaps * caps1, const GstCaps * caps2)
1415 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1416 guint j, k, len1, len2;
1418 GstStructure *struct1;
1419 GstStructure *struct2;
1421 GstStructure *istruct;
1423 g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
1424 g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
1426 /* caps are exactly the same pointers, just copy one caps */
1427 if (G_UNLIKELY (caps1 == caps2))
1428 return gst_caps_copy (caps1);
1430 /* empty caps on either side, return empty */
1431 if (G_UNLIKELY (gst_caps_is_empty (caps1) || gst_caps_is_empty (caps2)))
1432 return gst_caps_new_empty ();
1434 /* one of the caps is any, just copy the other caps */
1435 if (G_UNLIKELY (gst_caps_is_any (caps1)))
1436 return gst_caps_copy (caps2);
1437 if (G_UNLIKELY (gst_caps_is_any (caps2)))
1438 return gst_caps_copy (caps1);
1440 dest = gst_caps_new_empty ();
1442 /* run zigzag on top line then right line, this preserves the caps order
1443 * much better than a simple loop.
1445 * This algorithm zigzags over the caps structures as demonstrated in
1446 * the folowing matrix:
1454 * First we iterate over the caps1 structures (top line) intersecting
1455 * the structures diagonally down, then we iterate over the caps2
1458 len1 = caps1->structs->len;
1459 len2 = caps2->structs->len;
1460 for (i = 0; i < len1 + len2 - 1; i++) {
1461 /* caps1 index goes from 0 to caps1->structs->len-1 */
1462 j = MIN (i, len1 - 1);
1463 /* caps2 index stays 0 until i reaches caps1->structs->len, then it counts
1464 * up from 1 to caps2->structs->len - 1 */
1467 /* now run the diagonal line, end condition is the left or bottom
1470 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1471 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1473 istruct = gst_caps_structure_intersect (struct1, struct2);
1475 gst_caps_append_structure (dest, istruct);
1476 /* move down left */
1478 if (G_UNLIKELY (j == 0))
1479 break; /* so we don't roll back to G_MAXUINT */
1488 const GstStructure *subtract_from;
1495 gst_caps_structure_subtract_field (GQuark field_id, const GValue * value,
1498 SubtractionEntry *e = user_data;
1499 GValue subtraction = { 0, };
1500 const GValue *other;
1501 GstStructure *structure;
1503 other = gst_structure_id_get_value (e->subtract_from, field_id);
1507 if (!gst_value_subtract (&subtraction, other, value))
1509 if (gst_value_compare (&subtraction, other) == GST_VALUE_EQUAL) {
1510 g_value_unset (&subtraction);
1513 structure = gst_structure_copy (e->subtract_from);
1514 gst_structure_id_set_value (structure, field_id, &subtraction);
1515 g_value_unset (&subtraction);
1516 e->put_into = g_slist_prepend (e->put_into, structure);
1522 gst_caps_structure_subtract (GSList ** into, const GstStructure * minuend,
1523 const GstStructure * subtrahend)
1528 e.subtract_from = minuend;
1531 ret = gst_structure_foreach ((GstStructure *) subtrahend,
1532 gst_caps_structure_subtract_field, &e);
1538 for (walk = e.put_into; walk; walk = g_slist_next (walk)) {
1539 gst_structure_free (walk->data);
1541 g_slist_free (e.put_into);
1547 * gst_caps_subtract:
1548 * @minuend: #GstCaps to substract from
1549 * @subtrahend: #GstCaps to substract
1551 * Subtracts the @subtrahend from the @minuend.
1552 * <note>This function does not work reliably if optional properties for caps
1553 * are included on one caps and omitted on the other.</note>
1555 * Returns: the resulting caps
1558 gst_caps_subtract (const GstCaps * minuend, const GstCaps * subtrahend)
1563 GstCaps *dest = NULL, *src;
1565 g_return_val_if_fail (minuend != NULL, NULL);
1566 g_return_val_if_fail (subtrahend != NULL, NULL);
1568 if (gst_caps_is_empty (minuend) || gst_caps_is_any (subtrahend)) {
1569 return gst_caps_new_empty ();
1571 if (gst_caps_is_empty (subtrahend))
1572 return gst_caps_copy (minuend);
1574 /* FIXME: Do we want this here or above?
1575 The reason we need this is that there is no definition about what
1576 ANY means for specific types, so it's not possible to reduce ANY partially
1577 You can only remove everything or nothing and that is done above.
1578 Note: there's a test that checks this behaviour. */
1579 g_return_val_if_fail (!gst_caps_is_any (minuend), NULL);
1580 sublen = subtrahend->structs->len;
1581 g_assert (sublen > 0);
1583 src = gst_caps_copy (minuend);
1584 for (i = 0; i < sublen; i++) {
1587 sub = gst_caps_get_structure_unchecked (subtrahend, i);
1589 gst_caps_unref (src);
1592 dest = gst_caps_new_empty ();
1593 srclen = src->structs->len;
1594 for (j = 0; j < srclen; j++) {
1595 min = gst_caps_get_structure_unchecked (src, j);
1596 if (gst_structure_get_name_id (min) == gst_structure_get_name_id (sub)) {
1599 if (gst_caps_structure_subtract (&list, min, sub)) {
1602 for (walk = list; walk; walk = g_slist_next (walk)) {
1603 gst_caps_append_structure (dest, (GstStructure *) walk->data);
1605 g_slist_free (list);
1607 gst_caps_append_structure (dest, gst_structure_copy (min));
1610 gst_caps_append_structure (dest, gst_structure_copy (min));
1613 if (gst_caps_is_empty (dest)) {
1614 gst_caps_unref (src);
1619 gst_caps_unref (src);
1620 gst_caps_do_simplify (dest);
1626 * @caps1: a #GstCaps to union
1627 * @caps2: a #GstCaps to union
1629 * Creates a new #GstCaps that contains all the formats that are in
1630 * either @caps1 and @caps2.
1632 * Returns: the new #GstCaps
1635 gst_caps_union (const GstCaps * caps1, const GstCaps * caps2)
1640 /* NULL pointers are no correct GstCaps */
1641 g_return_val_if_fail (caps1 != NULL, NULL);
1642 g_return_val_if_fail (caps2 != NULL, NULL);
1644 if (gst_caps_is_empty (caps1))
1645 return gst_caps_copy (caps2);
1647 if (gst_caps_is_empty (caps2))
1648 return gst_caps_copy (caps1);
1650 if (gst_caps_is_any (caps1) || gst_caps_is_any (caps2))
1651 return gst_caps_new_any ();
1653 dest1 = gst_caps_copy (caps1);
1654 dest2 = gst_caps_copy (caps2);
1655 gst_caps_append (dest1, dest2);
1657 gst_caps_do_simplify (dest1);
1661 typedef struct _NormalizeForeach
1664 GstStructure *structure;
1669 gst_caps_normalize_foreach (GQuark field_id, const GValue * value, gpointer ptr)
1671 NormalizeForeach *nf = (NormalizeForeach *) ptr;
1675 if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
1676 guint len = gst_value_list_get_size (value);
1677 for (i = 1; i < len; i++) {
1678 const GValue *v = gst_value_list_get_value (value, i);
1679 GstStructure *structure = gst_structure_copy (nf->structure);
1681 gst_structure_id_set_value (structure, field_id, v);
1682 gst_caps_append_structure (nf->caps, structure);
1685 gst_value_init_and_copy (&val, gst_value_list_get_value (value, 0));
1686 gst_structure_id_set_value (nf->structure, field_id, &val);
1687 g_value_unset (&val);
1695 * gst_caps_normalize:
1696 * @caps: a #GstCaps to normalize
1698 * Creates a new #GstCaps that represents the same set of formats as
1699 * @caps, but contains no lists. Each list is expanded into separate
1702 * Returns: the new #GstCaps
1705 gst_caps_normalize (const GstCaps * caps)
1707 NormalizeForeach nf;
1711 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
1713 newcaps = gst_caps_copy (caps);
1715 nlen = newcaps->structs->len;
1717 for (i = 0; i < nlen; i++) {
1718 nf.structure = gst_caps_get_structure_unchecked (newcaps, i);
1720 while (!gst_structure_foreach (nf.structure,
1721 gst_caps_normalize_foreach, &nf));
1728 gst_caps_compare_structures (gconstpointer one, gconstpointer two)
1731 const GstStructure *struct1 = *((const GstStructure **) one);
1732 const GstStructure *struct2 = *((const GstStructure **) two);
1734 /* FIXME: this orders alphabetically, but ordering the quarks might be faster
1735 So what's the best way? */
1736 ret = strcmp (gst_structure_get_name (struct1),
1737 gst_structure_get_name (struct2));
1741 return gst_structure_n_fields (struct2) - gst_structure_n_fields (struct1);
1748 GstStructure *compare;
1753 gst_caps_structure_figure_out_union (GQuark field_id, const GValue * value,
1756 UnionField *u = user_data;
1757 const GValue *val = gst_structure_id_get_value (u->compare, field_id);
1761 g_value_unset (&u->value);
1764 if (gst_value_compare (val, value) == GST_VALUE_EQUAL)
1767 g_value_unset (&u->value);
1771 gst_value_union (&u->value, val, value);
1776 gst_caps_structure_simplify (GstStructure ** result,
1777 const GstStructure * simplify, GstStructure * compare)
1780 UnionField field = { 0, {0,}, NULL };
1782 /* try to subtract to get a real subset */
1783 if (gst_caps_structure_subtract (&list, simplify, compare)) {
1784 switch (g_slist_length (list)) {
1789 *result = list->data;
1790 g_slist_free (list);
1796 for (walk = list; walk; walk = g_slist_next (walk)) {
1797 gst_structure_free (walk->data);
1799 g_slist_free (list);
1805 /* try to union both structs */
1806 field.compare = compare;
1807 if (gst_structure_foreach ((GstStructure *) simplify,
1808 gst_caps_structure_figure_out_union, &field)) {
1809 gboolean ret = FALSE;
1811 /* now we know all of simplify's fields are the same in compare
1812 * but at most one field: field.name */
1813 if (G_IS_VALUE (&field.value)) {
1814 if (gst_structure_n_fields (simplify) == gst_structure_n_fields (compare)) {
1815 gst_structure_id_set_value (compare, field.name, &field.value);
1819 g_value_unset (&field.value);
1820 } else if (gst_structure_n_fields (simplify) <=
1821 gst_structure_n_fields (compare)) {
1822 /* compare is just more specific, will be optimized away later */
1823 /* FIXME: do this here? */
1824 GST_LOG ("found a case that will be optimized later.");
1826 gchar *one = gst_structure_to_string (simplify);
1827 gchar *two = gst_structure_to_string (compare);
1830 ("caps mismatch: structures %s and %s claim to be possible to unify, but aren't",
1842 gst_caps_switch_structures (GstCaps * caps, GstStructure * old,
1843 GstStructure * new, gint i)
1845 gst_structure_set_parent_refcount (old, NULL);
1846 gst_structure_free (old);
1847 gst_structure_set_parent_refcount (new, &caps->refcount);
1848 g_ptr_array_index (caps->structs, i) = new;
1852 * gst_caps_do_simplify:
1853 * @caps: a #GstCaps to simplify
1855 * Modifies the given @caps inplace into a representation that represents the
1856 * same set of formats, but in a simpler form. Component structures that are
1857 * identical are merged. Component structures that have values that can be
1858 * merged are also merged.
1860 * Returns: TRUE, if the caps could be simplified
1863 gst_caps_do_simplify (GstCaps * caps)
1865 GstStructure *simplify, *compare, *result = NULL;
1867 gboolean changed = FALSE;
1869 g_return_val_if_fail (caps != NULL, FALSE);
1870 g_return_val_if_fail (IS_WRITABLE (caps), FALSE);
1872 if (gst_caps_get_size (caps) < 2)
1875 g_ptr_array_sort (caps->structs, gst_caps_compare_structures);
1877 start = caps->structs->len - 1;
1878 for (i = caps->structs->len - 1; i >= 0; i--) {
1879 simplify = gst_caps_get_structure_unchecked (caps, i);
1880 if (gst_structure_get_name_id (simplify) !=
1881 gst_structure_get_name_id (gst_caps_get_structure_unchecked (caps,
1884 for (j = start; j >= 0; j--) {
1887 compare = gst_caps_get_structure_unchecked (caps, j);
1888 if (gst_structure_get_name_id (simplify) !=
1889 gst_structure_get_name_id (compare)) {
1892 if (gst_caps_structure_simplify (&result, simplify, compare)) {
1894 gst_caps_switch_structures (caps, simplify, result, i);
1897 gst_caps_remove_structure (caps, i);
1909 /* gst_caps_do_simplify (caps); */
1913 #ifndef GST_DISABLE_LOADSAVE
1915 * gst_caps_save_thyself:
1916 * @caps: a #GstCaps structure
1917 * @parent: a XML parent node
1919 * Serializes a #GstCaps to XML and adds it as a child node of @parent.
1921 * Returns: a XML node pointer
1924 gst_caps_save_thyself (const GstCaps * caps, xmlNodePtr parent)
1926 char *s = gst_caps_to_string (caps);
1928 xmlNewChild (parent, NULL, (xmlChar *) "caps", (xmlChar *) s);
1934 * gst_caps_load_thyself:
1935 * @parent: a XML node
1937 * Creates a #GstCaps from its XML serialization.
1939 * Returns: a new #GstCaps structure
1942 gst_caps_load_thyself (xmlNodePtr parent)
1944 if (strcmp ("caps", (char *) parent->name) == 0) {
1945 return gst_caps_from_string ((gchar *) xmlNodeGetContent (parent));
1956 * @caps: a pointer to #GstCaps
1957 * @newcaps: a #GstCaps to replace *caps
1959 * Replaces *caps with @newcaps. Unrefs the #GstCaps in the location
1960 * pointed to by @caps, if applicable, then modifies @caps to point to
1961 * @newcaps. An additional ref on @newcaps is taken.
1963 * This function does not take any locks so you might want to lock
1964 * the object owning @caps pointer.
1967 gst_caps_replace (GstCaps ** caps, GstCaps * newcaps)
1971 g_return_if_fail (caps != NULL);
1975 GST_CAT_LOG (GST_CAT_REFCOUNTING, "%p, %p -> %p", caps, oldcaps, newcaps);
1977 if (newcaps != oldcaps) {
1979 gst_caps_ref (newcaps);
1984 gst_caps_unref (oldcaps);
1989 * gst_caps_to_string:
1992 * Converts @caps to a string representation. This string representation
1993 * can be converted back to a #GstCaps by gst_caps_from_string().
1995 * For debugging purposes its easier to do something like this:
1997 * GST_LOG ("caps are %" GST_PTR_FORMAT, caps);
1999 * This prints the caps in human readble form.
2001 * Returns: a newly allocated string representing @caps.
2004 gst_caps_to_string (const GstCaps * caps)
2006 guint i, slen, clen;
2009 /* NOTE: This function is potentially called by the debug system,
2010 * so any calls to gst_log() (and GST_DEBUG(), GST_LOG(), etc.)
2011 * should be careful to avoid recursion. This includes any functions
2012 * called by gst_caps_to_string. In particular, calls should
2013 * not use the GST_PTR_FORMAT extension. */
2016 return g_strdup ("NULL");
2018 if (gst_caps_is_any (caps)) {
2019 return g_strdup ("ANY");
2021 if (gst_caps_is_empty (caps)) {
2022 return g_strdup ("EMPTY");
2025 /* estimate a rough string length to avoid unnecessary reallocs in GString */
2027 clen = caps->structs->len;
2028 for (i = 0; i < clen; i++) {
2030 STRUCTURE_ESTIMATED_STRING_LEN (gst_caps_get_structure_unchecked (caps,
2034 s = g_string_sized_new (slen);
2035 for (i = 0; i < clen; i++) {
2036 GstStructure *structure;
2039 /* ';' is now added by gst_structure_to_string */
2040 g_string_append_c (s, ' ');
2043 structure = gst_caps_get_structure_unchecked (caps, i);
2044 priv_gst_structure_append_to_gstring (structure, s);
2046 if (s->len && s->str[s->len - 1] == ';') {
2047 /* remove latest ';' */
2048 s->str[--s->len] = '\0';
2050 return g_string_free (s, FALSE);
2054 gst_caps_from_string_inplace (GstCaps * caps, const gchar * string)
2056 GstStructure *structure;
2059 g_return_val_if_fail (string, FALSE);
2060 if (strcmp ("ANY", string) == 0) {
2061 caps->flags = GST_CAPS_FLAGS_ANY;
2064 if (strcmp ("EMPTY", string) == 0) {
2068 structure = gst_structure_from_string (string, &s);
2069 if (structure == NULL) {
2072 gst_caps_append_structure (caps, structure);
2076 while (g_ascii_isspace (*s))
2081 structure = gst_structure_from_string (s, &s);
2082 if (structure == NULL) {
2085 gst_caps_append_structure (caps, structure);
2093 * gst_caps_from_string:
2094 * @string: a string to convert to #GstCaps
2096 * Converts @caps from a string representation.
2098 * Returns: a newly allocated #GstCaps
2101 gst_caps_from_string (const gchar * string)
2105 caps = gst_caps_new_empty ();
2106 if (gst_caps_from_string_inplace (caps, string)) {
2109 gst_caps_unref (caps);
2115 gst_caps_transform_to_string (const GValue * src_value, GValue * dest_value)
2117 g_return_if_fail (G_IS_VALUE (src_value));
2118 g_return_if_fail (G_IS_VALUE (dest_value));
2119 g_return_if_fail (G_VALUE_HOLDS (src_value, GST_TYPE_CAPS));
2120 g_return_if_fail (G_VALUE_HOLDS (dest_value, G_TYPE_STRING)
2121 || G_VALUE_HOLDS (dest_value, G_TYPE_POINTER));
2123 dest_value->data[0].v_pointer =
2124 gst_caps_to_string (src_value->data[0].v_pointer);
2128 gst_caps_copy_conditional (GstCaps * src)
2131 return gst_caps_ref (src);