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 #ifdef GST_DISABLE_DEPRECATED
77 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
78 #include <libxml/parser.h>
79 xmlNodePtr gst_caps_save_thyself (const GstCaps * caps, xmlNodePtr parent);
80 GstCaps *gst_caps_load_thyself (xmlNodePtr parent);
84 #define DEBUG_REFCOUNT
86 #define CAPS_POISON(caps) G_STMT_START{ \
88 GstCaps *_newcaps = gst_caps_copy (caps); \
89 gst_caps_unref(caps); \
93 #define STRUCTURE_POISON(structure) G_STMT_START{ \
95 GstStructure *_newstruct = gst_structure_copy (structure); \
96 gst_structure_free(structure); \
97 structure = _newstruct; \
100 #define IS_WRITABLE(caps) \
101 (g_atomic_int_get (&(caps)->refcount) == 1)
103 /* same as gst_caps_is_any () */
104 #define CAPS_IS_ANY(caps) \
105 ((caps)->flags & GST_CAPS_FLAGS_ANY)
107 /* same as gst_caps_is_empty () */
108 #define CAPS_IS_EMPTY(caps) \
109 (!CAPS_IS_ANY(caps) && CAPS_IS_EMPTY_SIMPLE(caps))
111 #define CAPS_IS_EMPTY_SIMPLE(caps) \
112 (((caps)->structs == NULL) || ((caps)->structs->len == 0))
114 /* quick way to get a caps structure at an index without doing a type or array
116 #define gst_caps_get_structure_unchecked(caps, index) \
117 ((GstStructure *)g_ptr_array_index ((caps)->structs, (index)))
118 /* quick way to append a structure without checking the args */
119 #define gst_caps_append_structure_unchecked(caps, structure) G_STMT_START{\
120 GstStructure *__s=structure; \
121 gst_structure_set_parent_refcount (__s, &caps->refcount); \
122 g_ptr_array_add (caps->structs, __s); \
125 /* lock to protect multiple invocations of static caps to caps conversion */
126 G_LOCK_DEFINE_STATIC (static_caps_lock);
128 static void gst_caps_transform_to_string (const GValue * src_value,
129 GValue * dest_value);
130 static gboolean gst_caps_from_string_inplace (GstCaps * caps,
131 const gchar * string);
132 static GstCaps *gst_caps_copy_conditional (GstCaps * src);
135 gst_caps_get_type (void)
137 static GType gst_caps_type = 0;
139 if (G_UNLIKELY (gst_caps_type == 0)) {
140 gst_caps_type = g_boxed_type_register_static ("GstCaps",
141 (GBoxedCopyFunc) gst_caps_copy_conditional,
142 (GBoxedFreeFunc) gst_caps_unref);
144 g_value_register_transform_func (gst_caps_type,
145 G_TYPE_STRING, gst_caps_transform_to_string);
148 return gst_caps_type;
151 /* creation/deletion */
154 * gst_caps_new_empty:
156 * Creates a new #GstCaps that is empty. That is, the returned
157 * #GstCaps contains no media formats.
158 * Caller is responsible for unreffing the returned caps.
160 * Returns: (transfer full): the new #GstCaps
163 gst_caps_new_empty (void)
165 GstCaps *caps = g_slice_new (GstCaps);
167 caps->type = GST_TYPE_CAPS;
170 caps->structs = g_ptr_array_new ();
171 /* the 32 has been determined by logging caps sizes in _gst_caps_free
172 * but g_ptr_array uses 16 anyway if it expands once, so this does not help
174 * caps->structs = g_ptr_array_sized_new (32);
177 #ifdef DEBUG_REFCOUNT
178 GST_CAT_LOG (GST_CAT_CAPS, "created caps %p", caps);
187 * Creates a new #GstCaps that indicates that it is compatible with
190 * Returns: (transfer full): the new #GstCaps
193 gst_caps_new_any (void)
195 GstCaps *caps = gst_caps_new_empty ();
197 caps->flags = GST_CAPS_FLAGS_ANY;
203 * gst_caps_new_simple:
204 * @media_type: the media type of the structure
205 * @fieldname: first field to set
206 * @...: additional arguments
208 * Creates a new #GstCaps that contains one #GstStructure. The
209 * structure is defined by the arguments, which have the same format
210 * as gst_structure_new().
211 * Caller is responsible for unreffing the returned caps.
213 * Returns: (transfer full): the new #GstCaps
216 gst_caps_new_simple (const char *media_type, const char *fieldname, ...)
219 GstStructure *structure;
222 caps = gst_caps_new_empty ();
224 va_start (var_args, fieldname);
225 structure = gst_structure_new_valist (media_type, fieldname, var_args);
229 gst_caps_append_structure_unchecked (caps, structure);
231 gst_caps_replace (&caps, NULL);
238 * @struct1: the first structure to add
239 * @...: additional structures to add
241 * Creates a new #GstCaps and adds all the structures listed as
242 * arguments. The list must be NULL-terminated. The structures
243 * are not copied; the returned #GstCaps owns the structures.
245 * Returns: (transfer full): the new #GstCaps
248 gst_caps_new_full (GstStructure * struct1, ...)
253 va_start (var_args, struct1);
254 caps = gst_caps_new_full_valist (struct1, var_args);
261 * gst_caps_new_full_valist:
262 * @structure: the first structure to add
263 * @var_args: additional structures to add
265 * Creates a new #GstCaps and adds all the structures listed as
266 * arguments. The list must be NULL-terminated. The structures
267 * are not copied; the returned #GstCaps owns the structures.
269 * Returns: (transfer full): the new #GstCaps
272 gst_caps_new_full_valist (GstStructure * structure, va_list var_args)
276 caps = gst_caps_new_empty ();
279 gst_caps_append_structure_unchecked (caps, structure);
280 structure = va_arg (var_args, GstStructure *);
288 * @caps: the #GstCaps to copy
290 * Creates a new #GstCaps as a copy of the old @caps. The new caps will have a
291 * refcount of 1, owned by the caller. The structures are copied as well.
293 * Note that this function is the semantic equivalent of a gst_caps_ref()
294 * followed by a gst_caps_make_writable(). If you only want to hold on to a
295 * reference to the data, you should use gst_caps_ref().
297 * When you are finished with the caps, call gst_caps_unref() on it.
299 * Returns: (transfer full): the new #GstCaps
302 gst_caps_copy (const GstCaps * caps)
305 GstStructure *structure;
308 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
310 newcaps = gst_caps_new_empty ();
311 newcaps->flags = caps->flags;
312 n = caps->structs->len;
314 for (i = 0; i < n; i++) {
315 structure = gst_caps_get_structure_unchecked (caps, i);
316 gst_caps_append_structure_unchecked (newcaps,
317 gst_structure_copy (structure));
324 _gst_caps_free (GstCaps * caps)
326 GstStructure *structure;
329 /* The refcount must be 0, but since we're only called by gst_caps_unref,
330 * don't bother testing. */
331 len = caps->structs->len;
332 /* This can be used to get statistics about caps sizes */
333 /*GST_CAT_INFO (GST_CAT_CAPS, "caps size: %d", len); */
334 for (i = 0; i < len; i++) {
335 structure = (GstStructure *) gst_caps_get_structure_unchecked (caps, i);
336 gst_structure_set_parent_refcount (structure, NULL);
337 gst_structure_free (structure);
339 g_ptr_array_free (caps->structs, TRUE);
341 memset (caps, 0xff, sizeof (GstCaps));
344 #ifdef DEBUG_REFCOUNT
345 GST_CAT_LOG (GST_CAT_CAPS, "freeing caps %p", caps);
347 g_slice_free (GstCaps, caps);
351 * gst_caps_make_writable:
352 * @caps: (transfer full): the #GstCaps to make writable
354 * Returns a writable copy of @caps.
356 * If there is only one reference count on @caps, the caller must be the owner,
357 * and so this function will return the caps object unchanged. If on the other
358 * hand there is more than one reference on the object, a new caps object will
359 * be returned. The caller's reference on @caps will be removed, and instead the
360 * caller will own a reference to the returned object.
362 * In short, this function unrefs the caps in the argument and refs the caps
363 * that it returns. Don't access the argument after calling this function. See
364 * also: gst_caps_ref().
366 * Returns: (transfer full): the same #GstCaps object.
369 gst_caps_make_writable (GstCaps * caps)
373 g_return_val_if_fail (caps != NULL, NULL);
375 /* we are the only instance reffing this caps */
376 if (IS_WRITABLE (caps))
380 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy caps");
381 copy = gst_caps_copy (caps);
382 gst_caps_unref (caps);
389 * @caps: the #GstCaps to reference
391 * Add a reference to a #GstCaps object.
393 * From this point on, until the caller calls gst_caps_unref() or
394 * gst_caps_make_writable(), it is guaranteed that the caps object will not
395 * change. This means its structures won't change, etc. To use a #GstCaps
396 * object, you must always have a refcount on it -- either the one made
397 * implicitly by e.g. gst_caps_new_simple(), or via taking one explicitly with
400 * Returns: (transfer full): the same #GstCaps object.
403 gst_caps_ref (GstCaps * caps)
405 g_return_val_if_fail (caps != NULL, NULL);
407 #ifdef DEBUG_REFCOUNT
408 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p %d->%d", caps,
409 GST_CAPS_REFCOUNT_VALUE (caps), GST_CAPS_REFCOUNT_VALUE (caps) + 1);
411 g_return_val_if_fail (GST_CAPS_REFCOUNT_VALUE (caps) > 0, NULL);
413 g_atomic_int_inc (&caps->refcount);
420 * @caps: (transfer full): the #GstCaps to unref
422 * Unref a #GstCaps and and free all its structures and the
423 * structures' values when the refcount reaches 0.
426 gst_caps_unref (GstCaps * caps)
428 g_return_if_fail (caps != NULL);
430 #ifdef DEBUG_REFCOUNT
431 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p %d->%d", caps,
432 GST_CAPS_REFCOUNT_VALUE (caps), GST_CAPS_REFCOUNT_VALUE (caps) - 1);
435 g_return_if_fail (GST_CAPS_REFCOUNT_VALUE (caps) > 0);
437 /* if we ended up with the refcount at zero, free the caps */
438 if (G_UNLIKELY (g_atomic_int_dec_and_test (&caps->refcount)))
439 _gst_caps_free (caps);
443 gst_static_caps_get_type (void)
445 static GType staticcaps_type = 0;
447 if (G_UNLIKELY (staticcaps_type == 0)) {
448 staticcaps_type = g_pointer_type_register_static ("GstStaticCaps");
450 return staticcaps_type;
455 * gst_static_caps_get:
456 * @static_caps: the #GstStaticCaps to convert
458 * Converts a #GstStaticCaps to a #GstCaps.
460 * Returns: (transfer full): a pointer to the #GstCaps. Unref after usage.
461 * Since the core holds an additional ref to the returned caps,
462 * use gst_caps_make_writable() on the returned caps to modify it.
465 gst_static_caps_get (GstStaticCaps * static_caps)
469 g_return_val_if_fail (static_caps != NULL, NULL);
471 caps = (GstCaps *) static_caps;
473 /* refcount is 0 when we need to convert */
474 if (G_UNLIKELY (g_atomic_int_get (&caps->refcount) == 0)) {
478 G_LOCK (static_caps_lock);
479 /* check if other thread already updated */
480 if (G_UNLIKELY (g_atomic_int_get (&caps->refcount) > 0))
483 string = static_caps->string;
485 if (G_UNLIKELY (string == NULL))
488 GST_CAT_LOG (GST_CAT_CAPS, "creating %p", static_caps);
490 /* we construct the caps on the stack, then copy over the struct into our
491 * real caps, refcount last. We do this because we must leave the refcount
492 * of the result caps to 0 so that other threads don't run away with the
493 * caps while we are constructing it. */
494 temp.type = GST_TYPE_CAPS;
496 temp.structs = g_ptr_array_new ();
498 /* initialize the caps to a refcount of 1 so the caps can be writable for
499 * the next statement */
502 /* convert to string */
503 if (G_UNLIKELY (!gst_caps_from_string_inplace (&temp, string)))
504 g_critical ("Could not convert static caps \"%s\"", string);
506 /* now copy stuff over to the real caps. */
507 caps->type = temp.type;
508 caps->flags = temp.flags;
509 caps->structs = temp.structs;
510 /* and bump the refcount so other threads can now read */
511 g_atomic_int_set (&caps->refcount, 1);
513 GST_CAT_LOG (GST_CAT_CAPS, "created %p", static_caps);
515 G_UNLOCK (static_caps_lock);
517 /* ref the caps, makes it not writable */
525 G_UNLOCK (static_caps_lock);
526 g_warning ("static caps %p string is NULL", static_caps);
533 static GstStructure *
534 gst_caps_remove_and_get_structure (GstCaps * caps, guint idx)
536 /* don't use index_fast, gst_caps_do_simplify relies on the order */
537 GstStructure *s = g_ptr_array_remove_index (caps->structs, idx);
539 gst_structure_set_parent_refcount (s, NULL);
544 * gst_caps_steal_structure:
545 * @caps: the #GstCaps to retrieve from
546 * @index: Index of the structure to retrieve
548 * Retrieves the stucture with the given index from the list of structures
549 * contained in @caps. The caller becomes the owner of the returned structure.
551 * Returns: (transfer full): a pointer to the #GstStructure corresponding
557 gst_caps_steal_structure (GstCaps * caps, guint index)
559 g_return_val_if_fail (caps != NULL, NULL);
560 g_return_val_if_fail (IS_WRITABLE (caps), NULL);
562 if (G_UNLIKELY (index >= caps->structs->len))
565 return gst_caps_remove_and_get_structure (caps, index);
569 gst_structure_is_equal_foreach (GQuark field_id, const GValue * val2,
572 GstStructure *struct1 = (GstStructure *) data;
573 const GValue *val1 = gst_structure_id_get_value (struct1, field_id);
575 if (G_UNLIKELY (val1 == NULL))
577 if (gst_value_compare (val1, val2) == GST_VALUE_EQUAL) {
585 gst_caps_structure_is_subset_field (GQuark field_id, const GValue * value,
588 GstStructure *subtract_from = user_data;
589 GValue subtraction = { 0, };
592 if (!(other = gst_structure_id_get_value (subtract_from, field_id)))
593 /* field is missing in one set */
596 /* equal values are subset */
597 if (gst_value_compare (other, value) == GST_VALUE_EQUAL)
605 * -> 1 - [1,2] = empty
609 * -> [1,2] - [1,3] = empty
613 * -> {1,3} - {1,2} = 3
616 * First caps subtraction needs to return a non-empty set, second
617 * subtractions needs to give en empty set.
619 if (gst_value_subtract (&subtraction, other, value)) {
620 g_value_unset (&subtraction);
621 /* !empty result, swapping must be empty */
622 if (!gst_value_subtract (&subtraction, value, other))
625 g_value_unset (&subtraction);
631 gst_caps_structure_is_subset (const GstStructure * minuend,
632 const GstStructure * subtrahend)
634 if ((minuend->name != subtrahend->name) ||
635 (gst_structure_n_fields (minuend) !=
636 gst_structure_n_fields (subtrahend))) {
640 return gst_structure_foreach ((GstStructure *) subtrahend,
641 gst_caps_structure_is_subset_field, (gpointer) minuend);
646 * @caps1: the #GstCaps that will be appended to
647 * @caps2: (transfer full): the #GstCaps to append
649 * Appends the structures contained in @caps2 to @caps1. The structures in
650 * @caps2 are not copied -- they are transferred to @caps1, and then @caps2 is
651 * freed. If either caps is ANY, the resulting caps will be ANY.
654 gst_caps_append (GstCaps * caps1, GstCaps * caps2)
656 GstStructure *structure;
659 g_return_if_fail (GST_IS_CAPS (caps1));
660 g_return_if_fail (GST_IS_CAPS (caps2));
661 g_return_if_fail (IS_WRITABLE (caps1));
662 g_return_if_fail (IS_WRITABLE (caps2));
667 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))) {
668 /* FIXME: this leaks */
669 caps1->flags |= GST_CAPS_FLAGS_ANY;
670 for (i = caps2->structs->len - 1; i >= 0; i--) {
671 structure = gst_caps_remove_and_get_structure (caps2, i);
672 gst_structure_free (structure);
675 for (i = caps2->structs->len; i; i--) {
676 structure = gst_caps_remove_and_get_structure (caps2, 0);
677 gst_caps_append_structure_unchecked (caps1, structure);
680 gst_caps_unref (caps2); /* guaranteed to free it */
685 * @caps1: the #GstCaps that will take the new entries
686 * @caps2: (transfer full): the #GstCaps to merge in
688 * Appends the structures contained in @caps2 to @caps1 if they are not yet
689 * expressed by @caps1. The structures in @caps2 are not copied -- they are
690 * transferred to @caps1, and then @caps2 is freed.
691 * If either caps is ANY, the resulting caps will be ANY.
696 gst_caps_merge (GstCaps * caps1, GstCaps * caps2)
698 GstStructure *structure;
701 g_return_if_fail (GST_IS_CAPS (caps1));
702 g_return_if_fail (GST_IS_CAPS (caps2));
703 g_return_if_fail (IS_WRITABLE (caps1));
704 g_return_if_fail (IS_WRITABLE (caps2));
709 if (G_UNLIKELY (CAPS_IS_ANY (caps1))) {
710 for (i = caps2->structs->len - 1; i >= 0; i--) {
711 structure = gst_caps_remove_and_get_structure (caps2, i);
712 gst_structure_free (structure);
714 } else if (G_UNLIKELY (CAPS_IS_ANY (caps2))) {
715 caps1->flags |= GST_CAPS_FLAGS_ANY;
716 for (i = caps1->structs->len - 1; i >= 0; i--) {
717 structure = gst_caps_remove_and_get_structure (caps1, i);
718 gst_structure_free (structure);
721 for (i = caps2->structs->len; i; i--) {
722 structure = gst_caps_remove_and_get_structure (caps2, 0);
723 gst_caps_merge_structure (caps1, structure);
726 GstCaps *com = gst_caps_intersect (caps1, caps2);
727 GstCaps *add = gst_caps_subtract (caps2, com);
729 GST_DEBUG ("common : %d", gst_caps_get_size (com));
730 GST_DEBUG ("adding : %d", gst_caps_get_size (add));
731 gst_caps_append (caps1, add);
732 gst_caps_unref (com);
735 gst_caps_unref (caps2); /* guaranteed to free it */
739 * gst_caps_append_structure:
740 * @caps: the #GstCaps that will be appended to
741 * @structure: (transfer full): the #GstStructure to append
743 * Appends @structure to @caps. The structure is not copied; @caps
744 * becomes the owner of @structure.
747 gst_caps_append_structure (GstCaps * caps, GstStructure * structure)
749 g_return_if_fail (GST_IS_CAPS (caps));
750 g_return_if_fail (IS_WRITABLE (caps));
752 if (G_LIKELY (structure)) {
753 g_return_if_fail (structure->parent_refcount == NULL);
756 STRUCTURE_POISON (structure);
759 gst_caps_append_structure_unchecked (caps, structure);
764 * gst_caps_remove_structure:
765 * @caps: the #GstCaps to remove from
766 * @idx: Index of the structure to remove
768 * removes the stucture with the given index from the list of structures
769 * contained in @caps.
772 gst_caps_remove_structure (GstCaps * caps, guint idx)
774 GstStructure *structure;
776 g_return_if_fail (caps != NULL);
777 g_return_if_fail (idx <= gst_caps_get_size (caps));
778 g_return_if_fail (IS_WRITABLE (caps));
780 structure = gst_caps_remove_and_get_structure (caps, idx);
781 gst_structure_free (structure);
785 * gst_caps_merge_structure:
786 * @caps: the #GstCaps that will the the new structure
787 * @structure: (transfer full): the #GstStructure to merge
789 * Appends @structure to @caps if its not already expressed by @caps. The
790 * structure is not copied; @caps becomes the owner of @structure.
793 gst_caps_merge_structure (GstCaps * caps, GstStructure * structure)
795 g_return_if_fail (GST_IS_CAPS (caps));
796 g_return_if_fail (IS_WRITABLE (caps));
798 if (G_LIKELY (structure)) {
799 GstStructure *structure1;
801 gboolean unique = TRUE;
803 g_return_if_fail (structure->parent_refcount == NULL);
806 STRUCTURE_POISON (structure);
809 /* check each structure */
810 for (i = caps->structs->len - 1; i >= 0; i--) {
811 structure1 = gst_caps_get_structure_unchecked (caps, i);
812 /* if structure is a subset of structure1, then skip it */
813 if (gst_caps_structure_is_subset (structure1, structure)) {
819 gst_caps_append_structure_unchecked (caps, structure);
821 gst_structure_free (structure);
830 * Gets the number of structures contained in @caps.
832 * Returns: the number of structures that @caps contains
835 gst_caps_get_size (const GstCaps * caps)
837 g_return_val_if_fail (GST_IS_CAPS (caps), 0);
839 return caps->structs->len;
843 * gst_caps_get_structure:
845 * @index: the index of the structure
847 * Finds the structure in @caps that has the index @index, and
850 * WARNING: This function takes a const GstCaps *, but returns a
851 * non-const GstStructure *. This is for programming convenience --
852 * the caller should be aware that structures inside a constant
853 * #GstCaps should not be modified. However, if you know the caps
854 * are writable, either because you have just copied them or made
855 * them writable with gst_caps_make_writable(), you may modify the
856 * structure returned in the usual way, e.g. with functions like
857 * gst_structure_set().
859 * You do not need to free or unref the structure returned, it
860 * belongs to the #GstCaps.
862 * Returns: (transfer none): a pointer to the #GstStructure corresponding
866 gst_caps_get_structure (const GstCaps * caps, guint index)
868 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
869 g_return_val_if_fail (index < caps->structs->len, NULL);
871 return gst_caps_get_structure_unchecked (caps, index);
876 * @caps: the #GstCaps to copy
877 * @nth: the nth structure to copy
879 * Creates a new #GstCaps and appends a copy of the nth structure
880 * contained in @caps.
882 * Returns: (transfer full): the new #GstCaps
885 gst_caps_copy_nth (const GstCaps * caps, guint nth)
888 GstStructure *structure;
890 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
892 newcaps = gst_caps_new_empty ();
893 newcaps->flags = caps->flags;
895 if (G_LIKELY (caps->structs->len > nth)) {
896 structure = gst_caps_get_structure_unchecked (caps, nth);
897 gst_caps_append_structure_unchecked (newcaps,
898 gst_structure_copy (structure));
906 * @caps: the #GstCaps to truncate
908 * Destructively discard all but the first structure from @caps. Useful when
909 * fixating. @caps must be writable.
912 gst_caps_truncate (GstCaps * caps)
916 g_return_if_fail (GST_IS_CAPS (caps));
917 g_return_if_fail (IS_WRITABLE (caps));
919 i = caps->structs->len - 1;
922 gst_caps_remove_structure (caps, i--);
926 * gst_caps_set_value:
927 * @caps: a writable caps
928 * @field: name of the field to set
929 * @value: value to set the field to
931 * Sets the given @field on all structures of @caps to the given @value.
932 * This is a convenience function for calling gst_structure_set_value() on
933 * all structures of @caps.
938 gst_caps_set_value (GstCaps * caps, const char *field, const GValue * value)
942 g_return_if_fail (GST_IS_CAPS (caps));
943 g_return_if_fail (IS_WRITABLE (caps));
944 g_return_if_fail (field != NULL);
945 g_return_if_fail (G_IS_VALUE (value));
947 len = caps->structs->len;
948 for (i = 0; i < len; i++) {
949 GstStructure *structure = gst_caps_get_structure_unchecked (caps, i);
950 gst_structure_set_value (structure, field, value);
955 * gst_caps_set_simple_valist:
956 * @caps: the #GstCaps to set
957 * @field: first field to set
958 * @varargs: additional parameters
960 * Sets fields in a #GstCaps. The arguments must be passed in the same
961 * manner as gst_structure_set(), and be NULL-terminated.
962 * <note>Prior to GStreamer version 0.10.26, this function failed when
963 * @caps was not simple. If your code needs to work with those versions
964 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
965 * is %TRUE for @caps.</note>
968 gst_caps_set_simple_valist (GstCaps * caps, const char *field, va_list varargs)
970 GValue value = { 0, };
972 g_return_if_fail (GST_IS_CAPS (caps));
973 g_return_if_fail (IS_WRITABLE (caps));
979 type = va_arg (varargs, GType);
981 if (G_UNLIKELY (type == G_TYPE_DATE)) {
982 g_warning ("Don't use G_TYPE_DATE, use GST_TYPE_DATE instead\n");
983 type = GST_TYPE_DATE;
985 #if GLIB_CHECK_VERSION(2,23,3)
986 G_VALUE_COLLECT_INIT (&value, type, varargs, 0, &err);
988 g_value_init (&value, type);
989 G_VALUE_COLLECT (&value, varargs, 0, &err);
991 if (G_UNLIKELY (err)) {
992 g_critical ("%s", err);
996 gst_caps_set_value (caps, field, &value);
998 g_value_unset (&value);
1000 field = va_arg (varargs, const gchar *);
1005 * gst_caps_set_simple:
1006 * @caps: the #GstCaps to set
1007 * @field: first field to set
1008 * @...: additional parameters
1010 * Sets fields in a #GstCaps. The arguments must be passed in the same
1011 * manner as gst_structure_set(), and be NULL-terminated.
1012 * <note>Prior to GStreamer version 0.10.26, this function failed when
1013 * @caps was not simple. If your code needs to work with those versions
1014 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
1015 * is %TRUE for @caps.</note>
1018 gst_caps_set_simple (GstCaps * caps, const char *field, ...)
1022 g_return_if_fail (GST_IS_CAPS (caps));
1023 g_return_if_fail (IS_WRITABLE (caps));
1025 va_start (var_args, field);
1026 gst_caps_set_simple_valist (caps, field, var_args);
1034 * @caps: the #GstCaps to test
1036 * Determines if @caps represents any media format.
1038 * Returns: TRUE if @caps represents any format.
1041 gst_caps_is_any (const GstCaps * caps)
1043 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1045 return (CAPS_IS_ANY (caps));
1049 * gst_caps_is_empty:
1050 * @caps: the #GstCaps to test
1052 * Determines if @caps represents no media formats.
1054 * Returns: TRUE if @caps represents no formats.
1057 gst_caps_is_empty (const GstCaps * caps)
1059 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1061 if (CAPS_IS_ANY (caps))
1064 return CAPS_IS_EMPTY_SIMPLE (caps);
1068 gst_caps_is_fixed_foreach (GQuark field_id, const GValue * value,
1071 return gst_value_is_fixed (value);
1075 * gst_caps_is_fixed:
1076 * @caps: the #GstCaps to test
1078 * Fixed #GstCaps describe exactly one format, that is, they have exactly
1079 * one structure, and each field in the structure describes a fixed type.
1080 * Examples of non-fixed types are GST_TYPE_INT_RANGE and GST_TYPE_LIST.
1082 * Returns: TRUE if @caps is fixed
1085 gst_caps_is_fixed (const GstCaps * caps)
1087 GstStructure *structure;
1089 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1091 if (caps->structs->len != 1)
1094 structure = gst_caps_get_structure_unchecked (caps, 0);
1096 return gst_structure_foreach (structure, gst_caps_is_fixed_foreach, NULL);
1100 * gst_caps_is_equal_fixed:
1101 * @caps1: the #GstCaps to test
1102 * @caps2: the #GstCaps to test
1104 * Tests if two #GstCaps are equal. This function only works on fixed
1107 * Returns: TRUE if the arguments represent the same format
1110 gst_caps_is_equal_fixed (const GstCaps * caps1, const GstCaps * caps2)
1112 GstStructure *struct1, *struct2;
1114 g_return_val_if_fail (gst_caps_is_fixed (caps1), FALSE);
1115 g_return_val_if_fail (gst_caps_is_fixed (caps2), FALSE);
1117 struct1 = gst_caps_get_structure_unchecked (caps1, 0);
1118 struct2 = gst_caps_get_structure_unchecked (caps2, 0);
1120 if (struct1->name != struct2->name) {
1123 if (struct1->fields->len != struct2->fields->len) {
1127 return gst_structure_foreach (struct1, gst_structure_is_equal_foreach,
1132 * gst_caps_is_always_compatible:
1133 * @caps1: the #GstCaps to test
1134 * @caps2: the #GstCaps to test
1136 * A given #GstCaps structure is always compatible with another if
1137 * every media format that is in the first is also contained in the
1138 * second. That is, @caps1 is a subset of @caps2.
1140 * Returns: TRUE if @caps1 is a subset of @caps2.
1143 gst_caps_is_always_compatible (const GstCaps * caps1, const GstCaps * caps2)
1145 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1146 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1148 return gst_caps_is_subset (caps1, caps2);
1152 * gst_caps_is_subset:
1153 * @subset: a #GstCaps
1154 * @superset: a potentially greater #GstCaps
1156 * Checks if all caps represented by @subset are also represented by @superset.
1157 * <note>This function does not work reliably if optional properties for caps
1158 * are included on one caps and omitted on the other.</note>
1160 * Returns: %TRUE if @subset is a subset of @superset
1163 gst_caps_is_subset (const GstCaps * subset, const GstCaps * superset)
1168 g_return_val_if_fail (subset != NULL, FALSE);
1169 g_return_val_if_fail (superset != NULL, FALSE);
1171 if (CAPS_IS_EMPTY (subset) || CAPS_IS_ANY (superset))
1173 if (CAPS_IS_ANY (subset) || CAPS_IS_EMPTY (superset))
1176 caps = gst_caps_subtract (subset, superset);
1177 ret = CAPS_IS_EMPTY_SIMPLE (caps);
1178 gst_caps_unref (caps);
1183 * gst_caps_is_equal:
1184 * @caps1: a #GstCaps
1185 * @caps2: another #GstCaps
1187 * Checks if the given caps represent the same set of caps.
1188 * <note>This function does not work reliably if optional properties for caps
1189 * are included on one caps and omitted on the other.</note>
1191 * This function deals correctly with passing NULL for any of the caps.
1193 * Returns: TRUE if both caps are equal.
1196 gst_caps_is_equal (const GstCaps * caps1, const GstCaps * caps2)
1198 /* FIXME 0.11: NULL pointers are no valid Caps but indicate an error
1199 * So there should be an assertion that caps1 and caps2 != NULL */
1201 /* NULL <-> NULL is allowed here */
1202 if (G_UNLIKELY (caps1 == caps2))
1205 /* one of them NULL => they are different (can't be both NULL because
1206 * we checked that above) */
1207 if (G_UNLIKELY (caps1 == NULL || caps2 == NULL))
1210 if (G_UNLIKELY (gst_caps_is_fixed (caps1) && gst_caps_is_fixed (caps2)))
1211 return gst_caps_is_equal_fixed (caps1, caps2);
1213 return gst_caps_is_subset (caps1, caps2) && gst_caps_is_subset (caps2, caps1);
1216 /* intersect operation */
1221 const GstStructure *intersect;
1226 gst_caps_structure_intersect_field1 (GQuark id, const GValue * val1,
1229 IntersectData *idata = (IntersectData *) data;
1230 const GValue *val2 = gst_structure_id_get_value (idata->intersect, id);
1232 if (G_UNLIKELY (val2 == NULL)) {
1233 gst_structure_id_set_value (idata->dest, id, val1);
1235 GValue dest_value = { 0 };
1236 if (gst_value_intersect (&dest_value, val1, val2)) {
1237 gst_structure_id_set_value (idata->dest, id, &dest_value);
1238 g_value_unset (&dest_value);
1247 gst_caps_structure_intersect_field2 (GQuark id, const GValue * val1,
1250 IntersectData *idata = (IntersectData *) data;
1251 const GValue *val2 = gst_structure_id_get_value (idata->intersect, id);
1253 if (G_UNLIKELY (val2 == NULL)) {
1254 gst_structure_id_set_value (idata->dest, id, val1);
1259 static GstStructure *
1260 gst_caps_structure_intersect (const GstStructure * struct1,
1261 const GstStructure * struct2)
1265 g_assert (struct1 != NULL);
1266 g_assert (struct2 != NULL);
1268 if (G_UNLIKELY (struct1->name != struct2->name))
1271 /* copy fields from struct1 which we have not in struct2 to target
1272 * intersect if we have the field in both */
1273 data.dest = gst_structure_id_empty_new (struct1->name);
1274 data.intersect = struct2;
1275 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct1,
1276 gst_caps_structure_intersect_field1, &data)))
1279 /* copy fields from struct2 which we have not in struct1 to target */
1280 data.intersect = struct1;
1281 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct2,
1282 gst_caps_structure_intersect_field2, &data)))
1288 gst_structure_free (data.dest);
1293 gst_caps_structure_can_intersect_field (GQuark id, const GValue * val1,
1296 GstStructure *other = (GstStructure *) data;
1297 const GValue *val2 = gst_structure_id_get_value (other, id);
1299 if (G_LIKELY (val2)) {
1300 if (!gst_value_can_intersect (val1, val2)) {
1303 gint eq = gst_value_compare (val1, val2);
1305 if (eq == GST_VALUE_UNORDERED) {
1306 /* we need to try interseting */
1307 GValue dest_value = { 0 };
1308 if (gst_value_intersect (&dest_value, val1, val2)) {
1309 g_value_unset (&dest_value);
1313 } else if (eq != GST_VALUE_EQUAL) {
1322 gst_caps_structure_can_intersect (const GstStructure * struct1,
1323 const GstStructure * struct2)
1325 g_assert (struct1 != NULL);
1326 g_assert (struct2 != NULL);
1328 if (G_UNLIKELY (struct1->name != struct2->name))
1331 /* tries to intersect if we have the field in both */
1332 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct1,
1333 gst_caps_structure_can_intersect_field, (gpointer) struct2)))
1340 * gst_caps_can_intersect:
1341 * @caps1: a #GstCaps to intersect
1342 * @caps2: a #GstCaps to intersect
1344 * Tries intersecting @caps1 and @caps2 and reports whether the result would not
1347 * Returns: %TRUE if intersection would be not empty
1352 gst_caps_can_intersect (const GstCaps * caps1, const GstCaps * caps2)
1354 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1355 guint j, k, len1, len2;
1356 GstStructure *struct1;
1357 GstStructure *struct2;
1359 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1360 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1362 /* caps are exactly the same pointers */
1363 if (G_UNLIKELY (caps1 == caps2))
1366 /* empty caps on either side, return empty */
1367 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1370 /* one of the caps is any */
1371 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2)))
1374 /* run zigzag on top line then right line, this preserves the caps order
1375 * much better than a simple loop.
1377 * This algorithm zigzags over the caps structures as demonstrated in
1378 * the folowing matrix:
1381 * +------------- total distance: +-------------
1382 * | 1 2 4 7 0 | 0 1 2 3
1383 * caps2 | 3 5 8 10 1 | 1 2 3 4
1384 * | 6 9 11 12 2 | 2 3 4 5
1386 * First we iterate over the caps1 structures (top line) intersecting
1387 * the structures diagonally down, then we iterate over the caps2
1388 * structures. The result is that the intersections are ordered based on the
1389 * sum of the indexes in the list.
1391 len1 = caps1->structs->len;
1392 len2 = caps2->structs->len;
1393 for (i = 0; i < len1 + len2 - 1; i++) {
1394 /* superset index goes from 0 to sgst_caps_structure_intersectuperset->structs->len-1 */
1395 j = MIN (i, len1 - 1);
1396 /* subset index stays 0 until i reaches superset->structs->len, then it
1397 * counts up from 1 to subset->structs->len - 1 */
1400 /* now run the diagonal line, end condition is the left or bottom
1403 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1404 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1406 if (gst_caps_structure_can_intersect (struct1, struct2)) {
1409 /* move down left */
1411 if (G_UNLIKELY (j == 0))
1412 break; /* so we don't roll back to G_MAXUINT */
1420 * gst_caps_intersect:
1421 * @caps1: a #GstCaps to intersect
1422 * @caps2: a #GstCaps to intersect
1424 * Creates a new #GstCaps that contains all the formats that are common
1425 * to both @caps1 and @caps2.
1427 * Returns: the new #GstCaps
1430 gst_caps_intersect (const GstCaps * caps1, const GstCaps * caps2)
1432 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1433 guint j, k, len1, len2;
1435 GstStructure *struct1;
1436 GstStructure *struct2;
1438 GstStructure *istruct;
1440 g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
1441 g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
1443 /* caps are exactly the same pointers, just copy one caps */
1444 if (G_UNLIKELY (caps1 == caps2))
1445 return gst_caps_copy (caps1);
1447 /* empty caps on either side, return empty */
1448 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1449 return gst_caps_new_empty ();
1451 /* one of the caps is any, just copy the other caps */
1452 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1453 return gst_caps_copy (caps2);
1454 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1455 return gst_caps_copy (caps1);
1457 dest = gst_caps_new_empty ();
1459 /* run zigzag on top line then right line, this preserves the caps order
1460 * much better than a simple loop.
1462 * This algorithm zigzags over the caps structures as demonstrated in
1463 * the folowing matrix:
1471 * First we iterate over the caps1 structures (top line) intersecting
1472 * the structures diagonally down, then we iterate over the caps2
1475 len1 = caps1->structs->len;
1476 len2 = caps2->structs->len;
1477 for (i = 0; i < len1 + len2 - 1; i++) {
1478 /* caps1 index goes from 0 to caps1->structs->len-1 */
1479 j = MIN (i, len1 - 1);
1480 /* caps2 index stays 0 until i reaches caps1->structs->len, then it counts
1481 * up from 1 to caps2->structs->len - 1 */
1484 /* now run the diagonal line, end condition is the left or bottom
1487 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1488 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1490 istruct = gst_caps_structure_intersect (struct1, struct2);
1492 gst_caps_append_structure (dest, istruct);
1493 /* move down left */
1495 if (G_UNLIKELY (j == 0))
1496 break; /* so we don't roll back to G_MAXUINT */
1503 /* subtract operation */
1507 const GstStructure *subtract_from;
1513 gst_caps_structure_subtract_field (GQuark field_id, const GValue * value,
1516 SubtractionEntry *e = user_data;
1517 GValue subtraction = { 0, };
1518 const GValue *other;
1519 GstStructure *structure;
1521 other = gst_structure_id_get_value (e->subtract_from, field_id);
1525 if (!gst_value_subtract (&subtraction, other, value))
1527 if (gst_value_compare (&subtraction, other) == GST_VALUE_EQUAL) {
1528 g_value_unset (&subtraction);
1531 structure = gst_structure_copy (e->subtract_from);
1532 gst_structure_id_set_value (structure, field_id, &subtraction);
1533 g_value_unset (&subtraction);
1534 e->put_into = g_slist_prepend (e->put_into, structure);
1540 gst_caps_structure_subtract (GSList ** into, const GstStructure * minuend,
1541 const GstStructure * subtrahend)
1546 e.subtract_from = minuend;
1549 ret = gst_structure_foreach ((GstStructure *) subtrahend,
1550 gst_caps_structure_subtract_field, &e);
1556 for (walk = e.put_into; walk; walk = g_slist_next (walk)) {
1557 gst_structure_free (walk->data);
1559 g_slist_free (e.put_into);
1565 * gst_caps_subtract:
1566 * @minuend: #GstCaps to substract from
1567 * @subtrahend: #GstCaps to substract
1569 * Subtracts the @subtrahend from the @minuend.
1570 * <note>This function does not work reliably if optional properties for caps
1571 * are included on one caps and omitted on the other.</note>
1573 * Returns: the resulting caps
1576 gst_caps_subtract (const GstCaps * minuend, const GstCaps * subtrahend)
1581 GstCaps *dest = NULL, *src;
1583 g_return_val_if_fail (minuend != NULL, NULL);
1584 g_return_val_if_fail (subtrahend != NULL, NULL);
1586 if (CAPS_IS_EMPTY (minuend) || CAPS_IS_ANY (subtrahend)) {
1587 return gst_caps_new_empty ();
1589 if (CAPS_IS_EMPTY_SIMPLE (subtrahend))
1590 return gst_caps_copy (minuend);
1592 /* FIXME: Do we want this here or above?
1593 The reason we need this is that there is no definition about what
1594 ANY means for specific types, so it's not possible to reduce ANY partially
1595 You can only remove everything or nothing and that is done above.
1596 Note: there's a test that checks this behaviour. */
1597 g_return_val_if_fail (!CAPS_IS_ANY (minuend), NULL);
1598 sublen = subtrahend->structs->len;
1599 g_assert (sublen > 0);
1601 src = gst_caps_copy (minuend);
1602 for (i = 0; i < sublen; i++) {
1605 sub = gst_caps_get_structure_unchecked (subtrahend, i);
1607 gst_caps_unref (src);
1610 dest = gst_caps_new_empty ();
1611 srclen = src->structs->len;
1612 for (j = 0; j < srclen; j++) {
1613 min = gst_caps_get_structure_unchecked (src, j);
1614 if (gst_structure_get_name_id (min) == gst_structure_get_name_id (sub)) {
1617 if (gst_caps_structure_subtract (&list, min, sub)) {
1620 for (walk = list; walk; walk = g_slist_next (walk)) {
1621 gst_caps_append_structure_unchecked (dest,
1622 (GstStructure *) walk->data);
1624 g_slist_free (list);
1626 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1629 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1632 if (CAPS_IS_EMPTY_SIMPLE (dest)) {
1633 gst_caps_unref (src);
1638 gst_caps_unref (src);
1639 gst_caps_do_simplify (dest);
1643 /* union operation */
1646 static GstStructure *
1647 gst_caps_structure_union (const GstStructure * struct1,
1648 const GstStructure * struct2)
1652 const GstStructureField *field1;
1653 const GstStructureField *field2;
1656 /* FIXME this doesn't actually work */
1658 if (struct1->name != struct2->name)
1661 dest = gst_structure_id_empty_new (struct1->name);
1663 for (i = 0; i < struct1->fields->len; i++) {
1664 GValue dest_value = { 0 };
1666 field1 = GST_STRUCTURE_FIELD (struct1, i);
1667 field2 = gst_structure_id_get_field (struct2, field1->name);
1669 if (field2 == NULL) {
1672 if (gst_value_union (&dest_value, &field1->value, &field2->value)) {
1673 gst_structure_set_value (dest, g_quark_to_string (field1->name),
1676 ret = gst_value_compare (&field1->value, &field2->value);
1687 * @caps1: a #GstCaps to union
1688 * @caps2: a #GstCaps to union
1690 * Creates a new #GstCaps that contains all the formats that are in
1691 * either @caps1 and @caps2.
1693 * Returns: the new #GstCaps
1696 gst_caps_union (const GstCaps * caps1, const GstCaps * caps2)
1701 /* NULL pointers are no correct GstCaps */
1702 g_return_val_if_fail (caps1 != NULL, NULL);
1703 g_return_val_if_fail (caps2 != NULL, NULL);
1705 if (CAPS_IS_EMPTY (caps1))
1706 return gst_caps_copy (caps2);
1708 if (CAPS_IS_EMPTY (caps2))
1709 return gst_caps_copy (caps1);
1711 if (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))
1712 return gst_caps_new_any ();
1714 dest1 = gst_caps_copy (caps1);
1715 dest2 = gst_caps_copy (caps2);
1716 gst_caps_append (dest1, dest2);
1718 gst_caps_do_simplify (dest1);
1722 /* normalize/simplify operations */
1724 typedef struct _NormalizeForeach
1727 GstStructure *structure;
1732 gst_caps_normalize_foreach (GQuark field_id, const GValue * value, gpointer ptr)
1734 NormalizeForeach *nf = (NormalizeForeach *) ptr;
1738 if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
1739 guint len = gst_value_list_get_size (value);
1740 for (i = 1; i < len; i++) {
1741 const GValue *v = gst_value_list_get_value (value, i);
1742 GstStructure *structure = gst_structure_copy (nf->structure);
1744 gst_structure_id_set_value (structure, field_id, v);
1745 gst_caps_append_structure_unchecked (nf->caps, structure);
1748 gst_value_init_and_copy (&val, gst_value_list_get_value (value, 0));
1749 gst_structure_id_set_value (nf->structure, field_id, &val);
1750 g_value_unset (&val);
1758 * gst_caps_normalize:
1759 * @caps: a #GstCaps to normalize
1761 * Creates a new #GstCaps that represents the same set of formats as
1762 * @caps, but contains no lists. Each list is expanded into separate
1765 * Returns: the new #GstCaps
1768 gst_caps_normalize (const GstCaps * caps)
1770 NormalizeForeach nf;
1774 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
1776 newcaps = gst_caps_copy (caps);
1779 for (i = 0; i < gst_caps_get_size (newcaps); i++) {
1780 nf.structure = gst_caps_get_structure_unchecked (newcaps, i);
1782 while (!gst_structure_foreach (nf.structure,
1783 gst_caps_normalize_foreach, &nf));
1790 gst_caps_compare_structures (gconstpointer one, gconstpointer two)
1793 const GstStructure *struct1 = *((const GstStructure **) one);
1794 const GstStructure *struct2 = *((const GstStructure **) two);
1796 /* FIXME: this orders alphabetically, but ordering the quarks might be faster
1797 So what's the best way? */
1798 ret = strcmp (gst_structure_get_name (struct1),
1799 gst_structure_get_name (struct2));
1803 return gst_structure_n_fields (struct2) - gst_structure_n_fields (struct1);
1810 GstStructure *compare;
1815 gst_caps_structure_figure_out_union (GQuark field_id, const GValue * value,
1818 UnionField *u = user_data;
1819 const GValue *val = gst_structure_id_get_value (u->compare, field_id);
1823 g_value_unset (&u->value);
1826 if (gst_value_compare (val, value) == GST_VALUE_EQUAL)
1829 g_value_unset (&u->value);
1833 gst_value_union (&u->value, val, value);
1838 gst_caps_structure_simplify (GstStructure ** result,
1839 const GstStructure * simplify, GstStructure * compare)
1842 UnionField field = { 0, {0,}, NULL };
1844 /* try to subtract to get a real subset */
1845 if (gst_caps_structure_subtract (&list, simplify, compare)) {
1846 if (list == NULL) { /* no result */
1849 } else if (list->next == NULL) { /* one result */
1850 *result = list->data;
1851 g_slist_free (list);
1853 } else { /* multiple results */
1854 g_slist_foreach (list, (GFunc) gst_structure_free, NULL);
1855 g_slist_free (list);
1860 /* try to union both structs */
1861 field.compare = compare;
1862 if (gst_structure_foreach ((GstStructure *) simplify,
1863 gst_caps_structure_figure_out_union, &field)) {
1864 gboolean ret = FALSE;
1866 /* now we know all of simplify's fields are the same in compare
1867 * but at most one field: field.name */
1868 if (G_IS_VALUE (&field.value)) {
1869 if (gst_structure_n_fields (simplify) == gst_structure_n_fields (compare)) {
1870 gst_structure_id_set_value (compare, field.name, &field.value);
1874 g_value_unset (&field.value);
1875 } else if (gst_structure_n_fields (simplify) <=
1876 gst_structure_n_fields (compare)) {
1877 /* compare is just more specific, will be optimized away later */
1878 /* FIXME: do this here? */
1879 GST_LOG ("found a case that will be optimized later.");
1881 gchar *one = gst_structure_to_string (simplify);
1882 gchar *two = gst_structure_to_string (compare);
1885 ("caps mismatch: structures %s and %s claim to be possible to unify, but aren't",
1897 gst_caps_switch_structures (GstCaps * caps, GstStructure * old,
1898 GstStructure * new, gint i)
1900 gst_structure_set_parent_refcount (old, NULL);
1901 gst_structure_free (old);
1902 gst_structure_set_parent_refcount (new, &caps->refcount);
1903 g_ptr_array_index (caps->structs, i) = new;
1907 * gst_caps_do_simplify:
1908 * @caps: a #GstCaps to simplify
1910 * Modifies the given @caps inplace into a representation that represents the
1911 * same set of formats, but in a simpler form. Component structures that are
1912 * identical are merged. Component structures that have values that can be
1913 * merged are also merged.
1915 * Returns: TRUE, if the caps could be simplified
1918 gst_caps_do_simplify (GstCaps * caps)
1920 GstStructure *simplify, *compare, *result = NULL;
1922 gboolean changed = FALSE;
1924 g_return_val_if_fail (caps != NULL, FALSE);
1925 g_return_val_if_fail (IS_WRITABLE (caps), FALSE);
1927 if (gst_caps_get_size (caps) < 2)
1930 g_ptr_array_sort (caps->structs, gst_caps_compare_structures);
1932 start = caps->structs->len - 1;
1933 for (i = caps->structs->len - 1; i >= 0; i--) {
1934 simplify = gst_caps_get_structure_unchecked (caps, i);
1935 if (gst_structure_get_name_id (simplify) !=
1936 gst_structure_get_name_id (gst_caps_get_structure_unchecked (caps,
1939 for (j = start; j >= 0; j--) {
1942 compare = gst_caps_get_structure_unchecked (caps, j);
1943 if (gst_structure_get_name_id (simplify) !=
1944 gst_structure_get_name_id (compare)) {
1947 if (gst_caps_structure_simplify (&result, simplify, compare)) {
1949 gst_caps_switch_structures (caps, simplify, result, i);
1952 gst_caps_remove_structure (caps, i);
1964 /* gst_caps_do_simplify (caps); */
1970 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
1972 * gst_caps_save_thyself:
1973 * @caps: a #GstCaps structure
1974 * @parent: a XML parent node
1976 * Serializes a #GstCaps to XML and adds it as a child node of @parent.
1978 * Returns: a XML node pointer
1981 gst_caps_save_thyself (const GstCaps * caps, xmlNodePtr parent)
1983 char *s = gst_caps_to_string (caps);
1985 xmlNewChild (parent, NULL, (xmlChar *) "caps", (xmlChar *) s);
1991 * gst_caps_load_thyself:
1992 * @parent: a XML node
1994 * Creates a #GstCaps from its XML serialization.
1996 * Returns: a new #GstCaps structure
1999 gst_caps_load_thyself (xmlNodePtr parent)
2001 if (strcmp ("caps", (char *) parent->name) == 0) {
2002 return gst_caps_from_string ((gchar *) xmlNodeGetContent (parent));
2013 * @caps: (inout) (transfer full): a pointer to #GstCaps
2014 * @newcaps: a #GstCaps to replace *caps
2016 * Replaces *caps with @newcaps. Unrefs the #GstCaps in the location
2017 * pointed to by @caps, if applicable, then modifies @caps to point to
2018 * @newcaps. An additional ref on @newcaps is taken.
2020 * This function does not take any locks so you might want to lock
2021 * the object owning @caps pointer.
2024 gst_caps_replace (GstCaps ** caps, GstCaps * newcaps)
2028 g_return_if_fail (caps != NULL);
2032 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p, %p -> %p", caps, oldcaps, newcaps);
2034 if (newcaps != oldcaps) {
2036 gst_caps_ref (newcaps);
2041 gst_caps_unref (oldcaps);
2046 * gst_caps_to_string:
2049 * Converts @caps to a string representation. This string representation
2050 * can be converted back to a #GstCaps by gst_caps_from_string().
2052 * For debugging purposes its easier to do something like this:
2054 * GST_LOG ("caps are %" GST_PTR_FORMAT, caps);
2056 * This prints the caps in human readble form.
2058 * Returns: (transfer full): a newly allocated string representing @caps.
2061 gst_caps_to_string (const GstCaps * caps)
2063 guint i, slen, clen;
2066 /* NOTE: This function is potentially called by the debug system,
2067 * so any calls to gst_log() (and GST_DEBUG(), GST_LOG(), etc.)
2068 * should be careful to avoid recursion. This includes any functions
2069 * called by gst_caps_to_string. In particular, calls should
2070 * not use the GST_PTR_FORMAT extension. */
2073 return g_strdup ("NULL");
2075 if (CAPS_IS_ANY (caps)) {
2076 return g_strdup ("ANY");
2078 if (CAPS_IS_EMPTY_SIMPLE (caps)) {
2079 return g_strdup ("EMPTY");
2082 /* estimate a rough string length to avoid unnecessary reallocs in GString */
2084 clen = caps->structs->len;
2085 for (i = 0; i < clen; i++) {
2087 STRUCTURE_ESTIMATED_STRING_LEN (gst_caps_get_structure_unchecked (caps,
2091 s = g_string_sized_new (slen);
2092 for (i = 0; i < clen; i++) {
2093 GstStructure *structure;
2096 /* ';' is now added by gst_structure_to_string */
2097 g_string_append_c (s, ' ');
2100 structure = gst_caps_get_structure_unchecked (caps, i);
2101 priv_gst_structure_append_to_gstring (structure, s);
2103 if (s->len && s->str[s->len - 1] == ';') {
2104 /* remove latest ';' */
2105 s->str[--s->len] = '\0';
2107 return g_string_free (s, FALSE);
2111 gst_caps_from_string_inplace (GstCaps * caps, const gchar * string)
2113 GstStructure *structure;
2116 if (strcmp ("ANY", string) == 0) {
2117 caps->flags = GST_CAPS_FLAGS_ANY;
2120 if (strcmp ("EMPTY", string) == 0) {
2124 structure = gst_structure_from_string (string, &s);
2125 if (structure == NULL) {
2128 gst_caps_append_structure_unchecked (caps, structure);
2132 while (g_ascii_isspace (*s))
2137 structure = gst_structure_from_string (s, &s);
2138 if (structure == NULL) {
2141 gst_caps_append_structure_unchecked (caps, structure);
2149 * gst_caps_from_string:
2150 * @string: a string to convert to #GstCaps
2152 * Converts @caps from a string representation.
2154 * Returns: (transfer full): a newly allocated #GstCaps
2157 gst_caps_from_string (const gchar * string)
2161 g_return_val_if_fail (string, FALSE);
2163 caps = gst_caps_new_empty ();
2164 if (gst_caps_from_string_inplace (caps, string)) {
2167 gst_caps_unref (caps);
2173 gst_caps_transform_to_string (const GValue * src_value, GValue * dest_value)
2175 g_return_if_fail (G_IS_VALUE (src_value));
2176 g_return_if_fail (G_IS_VALUE (dest_value));
2177 g_return_if_fail (G_VALUE_HOLDS (src_value, GST_TYPE_CAPS));
2178 g_return_if_fail (G_VALUE_HOLDS (dest_value, G_TYPE_STRING)
2179 || G_VALUE_HOLDS (dest_value, G_TYPE_POINTER));
2181 dest_value->data[0].v_pointer =
2182 gst_caps_to_string (src_value->data[0].v_pointer);
2186 gst_caps_copy_conditional (GstCaps * src)
2189 return gst_caps_ref (src);