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_zig_zag (const GstCaps * caps1, const GstCaps * caps2)
1422 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1423 guint j, k, len1, len2;
1425 GstStructure *struct1;
1426 GstStructure *struct2;
1428 GstStructure *istruct;
1430 /* caps are exactly the same pointers, just copy one caps */
1431 if (G_UNLIKELY (caps1 == caps2))
1432 return gst_caps_copy (caps1);
1434 /* empty caps on either side, return empty */
1435 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1436 return gst_caps_new_empty ();
1438 /* one of the caps is any, just copy the other caps */
1439 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1440 return gst_caps_copy (caps2);
1441 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1442 return gst_caps_copy (caps1);
1444 dest = gst_caps_new_empty ();
1446 /* run zigzag on top line then right line, this preserves the caps order
1447 * much better than a simple loop.
1449 * This algorithm zigzags over the caps structures as demonstrated in
1450 * the folowing matrix:
1458 * First we iterate over the caps1 structures (top line) intersecting
1459 * the structures diagonally down, then we iterate over the caps2
1462 len1 = caps1->structs->len;
1463 len2 = caps2->structs->len;
1464 for (i = 0; i < len1 + len2 - 1; i++) {
1465 /* caps1 index goes from 0 to caps1->structs->len-1 */
1466 j = MIN (i, len1 - 1);
1467 /* caps2 index stays 0 until i reaches caps1->structs->len, then it counts
1468 * up from 1 to caps2->structs->len - 1 */
1471 /* now run the diagonal line, end condition is the left or bottom
1474 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1475 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1477 istruct = gst_caps_structure_intersect (struct1, struct2);
1479 gst_caps_append_structure (dest, istruct);
1480 /* move down left */
1482 if (G_UNLIKELY (j == 0))
1483 break; /* so we don't roll back to G_MAXUINT */
1491 * gst_caps_intersect_first:
1492 * @caps1: a #GstCaps to intersect
1493 * @caps2: a #GstCaps to intersect
1495 * Creates a new #GstCaps that contains all the formats that are common
1496 * to both @caps1 and @caps2.
1498 * Unlike @gst_caps_intersect, the returned caps will be ordered in a similar
1499 * fashion as @caps1.
1501 * Returns: the new #GstCaps
1504 gst_caps_intersect_first (const GstCaps * caps1, const GstCaps * caps2)
1506 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1507 guint j, len1, len2;
1509 GstStructure *struct1;
1510 GstStructure *struct2;
1512 GstStructure *istruct;
1514 /* caps are exactly the same pointers, just copy one caps */
1515 if (G_UNLIKELY (caps1 == caps2))
1516 return gst_caps_copy (caps1);
1518 /* empty caps on either side, return empty */
1519 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1520 return gst_caps_new_empty ();
1522 /* one of the caps is any, just copy the other caps */
1523 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1524 return gst_caps_copy (caps2);
1525 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1526 return gst_caps_copy (caps1);
1528 dest = gst_caps_new_empty ();
1530 len1 = caps1->structs->len;
1531 len2 = caps2->structs->len;
1532 for (i = 0; i < len1; i++) {
1533 struct1 = gst_caps_get_structure_unchecked (caps1, i);
1534 for (j = 0; j < len2; j++) {
1535 struct2 = gst_caps_get_structure_unchecked (caps2, j);
1536 istruct = gst_caps_structure_intersect (struct1, struct2);
1538 gst_caps_append_structure (dest, istruct);
1546 * gst_caps_intersect_full:
1547 * @caps1: a #GstCaps to intersect
1548 * @caps2: a #GstCaps to intersect
1549 * @mode: The intersection algorithm/mode to use
1551 * Creates a new #GstCaps that contains all the formats that are common
1552 * to both @caps1 and @caps2, the order is defined by the #GstCapsIntersectMode
1555 * Returns: the new #GstCaps
1559 gst_caps_intersect_full (const GstCaps * caps1, const GstCaps * caps2,
1560 GstCapsIntersectMode mode)
1562 g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
1563 g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
1566 case GST_CAPS_INTERSECT_FIRST:
1567 return gst_caps_intersect_first (caps1, caps2);
1569 g_warning ("Unknown caps intersect mode: %d", mode);
1571 case GST_CAPS_INTERSECT_ZIG_ZAG:
1572 return gst_caps_intersect_zig_zag (caps1, caps2);
1577 * gst_caps_intersect:
1578 * @caps1: a #GstCaps to intersect
1579 * @caps2: a #GstCaps to intersect
1581 * Creates a new #GstCaps that contains all the formats that are common
1582 * to both @caps1 and @caps2. Defaults to %GST_CAPS_INTERSECT_ZIG_ZAG mode.
1584 * Returns: the new #GstCaps
1587 gst_caps_intersect (const GstCaps * caps1, const GstCaps * caps2)
1589 return gst_caps_intersect_full (caps1, caps2, GST_CAPS_INTERSECT_ZIG_ZAG);
1593 /* subtract operation */
1597 const GstStructure *subtract_from;
1603 gst_caps_structure_subtract_field (GQuark field_id, const GValue * value,
1606 SubtractionEntry *e = user_data;
1607 GValue subtraction = { 0, };
1608 const GValue *other;
1609 GstStructure *structure;
1611 other = gst_structure_id_get_value (e->subtract_from, field_id);
1615 if (!gst_value_subtract (&subtraction, other, value))
1617 if (gst_value_compare (&subtraction, other) == GST_VALUE_EQUAL) {
1618 g_value_unset (&subtraction);
1621 structure = gst_structure_copy (e->subtract_from);
1622 gst_structure_id_set_value (structure, field_id, &subtraction);
1623 g_value_unset (&subtraction);
1624 e->put_into = g_slist_prepend (e->put_into, structure);
1630 gst_caps_structure_subtract (GSList ** into, const GstStructure * minuend,
1631 const GstStructure * subtrahend)
1636 e.subtract_from = minuend;
1639 ret = gst_structure_foreach ((GstStructure *) subtrahend,
1640 gst_caps_structure_subtract_field, &e);
1646 for (walk = e.put_into; walk; walk = g_slist_next (walk)) {
1647 gst_structure_free (walk->data);
1649 g_slist_free (e.put_into);
1655 * gst_caps_subtract:
1656 * @minuend: #GstCaps to substract from
1657 * @subtrahend: #GstCaps to substract
1659 * Subtracts the @subtrahend from the @minuend.
1660 * <note>This function does not work reliably if optional properties for caps
1661 * are included on one caps and omitted on the other.</note>
1663 * Returns: the resulting caps
1666 gst_caps_subtract (const GstCaps * minuend, const GstCaps * subtrahend)
1671 GstCaps *dest = NULL, *src;
1673 g_return_val_if_fail (minuend != NULL, NULL);
1674 g_return_val_if_fail (subtrahend != NULL, NULL);
1676 if (CAPS_IS_EMPTY (minuend) || CAPS_IS_ANY (subtrahend)) {
1677 return gst_caps_new_empty ();
1679 if (CAPS_IS_EMPTY_SIMPLE (subtrahend))
1680 return gst_caps_copy (minuend);
1682 /* FIXME: Do we want this here or above?
1683 The reason we need this is that there is no definition about what
1684 ANY means for specific types, so it's not possible to reduce ANY partially
1685 You can only remove everything or nothing and that is done above.
1686 Note: there's a test that checks this behaviour. */
1687 g_return_val_if_fail (!CAPS_IS_ANY (minuend), NULL);
1688 sublen = subtrahend->structs->len;
1689 g_assert (sublen > 0);
1691 src = gst_caps_copy (minuend);
1692 for (i = 0; i < sublen; i++) {
1695 sub = gst_caps_get_structure_unchecked (subtrahend, i);
1697 gst_caps_unref (src);
1700 dest = gst_caps_new_empty ();
1701 srclen = src->structs->len;
1702 for (j = 0; j < srclen; j++) {
1703 min = gst_caps_get_structure_unchecked (src, j);
1704 if (gst_structure_get_name_id (min) == gst_structure_get_name_id (sub)) {
1707 if (gst_caps_structure_subtract (&list, min, sub)) {
1710 for (walk = list; walk; walk = g_slist_next (walk)) {
1711 gst_caps_append_structure_unchecked (dest,
1712 (GstStructure *) walk->data);
1714 g_slist_free (list);
1716 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1719 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1722 if (CAPS_IS_EMPTY_SIMPLE (dest)) {
1723 gst_caps_unref (src);
1728 gst_caps_unref (src);
1729 gst_caps_do_simplify (dest);
1733 /* union operation */
1736 static GstStructure *
1737 gst_caps_structure_union (const GstStructure * struct1,
1738 const GstStructure * struct2)
1742 const GstStructureField *field1;
1743 const GstStructureField *field2;
1746 /* FIXME this doesn't actually work */
1748 if (struct1->name != struct2->name)
1751 dest = gst_structure_id_empty_new (struct1->name);
1753 for (i = 0; i < struct1->fields->len; i++) {
1754 GValue dest_value = { 0 };
1756 field1 = GST_STRUCTURE_FIELD (struct1, i);
1757 field2 = gst_structure_id_get_field (struct2, field1->name);
1759 if (field2 == NULL) {
1762 if (gst_value_union (&dest_value, &field1->value, &field2->value)) {
1763 gst_structure_set_value (dest, g_quark_to_string (field1->name),
1766 ret = gst_value_compare (&field1->value, &field2->value);
1777 * @caps1: a #GstCaps to union
1778 * @caps2: a #GstCaps to union
1780 * Creates a new #GstCaps that contains all the formats that are in
1781 * either @caps1 and @caps2.
1783 * Returns: the new #GstCaps
1786 gst_caps_union (const GstCaps * caps1, const GstCaps * caps2)
1791 /* NULL pointers are no correct GstCaps */
1792 g_return_val_if_fail (caps1 != NULL, NULL);
1793 g_return_val_if_fail (caps2 != NULL, NULL);
1795 if (CAPS_IS_EMPTY (caps1))
1796 return gst_caps_copy (caps2);
1798 if (CAPS_IS_EMPTY (caps2))
1799 return gst_caps_copy (caps1);
1801 if (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))
1802 return gst_caps_new_any ();
1804 dest1 = gst_caps_copy (caps1);
1805 dest2 = gst_caps_copy (caps2);
1806 gst_caps_append (dest1, dest2);
1808 gst_caps_do_simplify (dest1);
1812 /* normalize/simplify operations */
1814 typedef struct _NormalizeForeach
1817 GstStructure *structure;
1822 gst_caps_normalize_foreach (GQuark field_id, const GValue * value, gpointer ptr)
1824 NormalizeForeach *nf = (NormalizeForeach *) ptr;
1828 if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
1829 guint len = gst_value_list_get_size (value);
1830 for (i = 1; i < len; i++) {
1831 const GValue *v = gst_value_list_get_value (value, i);
1832 GstStructure *structure = gst_structure_copy (nf->structure);
1834 gst_structure_id_set_value (structure, field_id, v);
1835 gst_caps_append_structure_unchecked (nf->caps, structure);
1838 gst_value_init_and_copy (&val, gst_value_list_get_value (value, 0));
1839 gst_structure_id_set_value (nf->structure, field_id, &val);
1840 g_value_unset (&val);
1848 * gst_caps_normalize:
1849 * @caps: a #GstCaps to normalize
1851 * Creates a new #GstCaps that represents the same set of formats as
1852 * @caps, but contains no lists. Each list is expanded into separate
1855 * Returns: the new #GstCaps
1858 gst_caps_normalize (const GstCaps * caps)
1860 NormalizeForeach nf;
1864 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
1866 newcaps = gst_caps_copy (caps);
1869 for (i = 0; i < gst_caps_get_size (newcaps); i++) {
1870 nf.structure = gst_caps_get_structure_unchecked (newcaps, i);
1872 while (!gst_structure_foreach (nf.structure,
1873 gst_caps_normalize_foreach, &nf));
1880 gst_caps_compare_structures (gconstpointer one, gconstpointer two)
1883 const GstStructure *struct1 = *((const GstStructure **) one);
1884 const GstStructure *struct2 = *((const GstStructure **) two);
1886 /* FIXME: this orders alphabetically, but ordering the quarks might be faster
1887 So what's the best way? */
1888 ret = strcmp (gst_structure_get_name (struct1),
1889 gst_structure_get_name (struct2));
1893 return gst_structure_n_fields (struct2) - gst_structure_n_fields (struct1);
1900 GstStructure *compare;
1905 gst_caps_structure_figure_out_union (GQuark field_id, const GValue * value,
1908 UnionField *u = user_data;
1909 const GValue *val = gst_structure_id_get_value (u->compare, field_id);
1913 g_value_unset (&u->value);
1916 if (gst_value_compare (val, value) == GST_VALUE_EQUAL)
1919 g_value_unset (&u->value);
1923 gst_value_union (&u->value, val, value);
1928 gst_caps_structure_simplify (GstStructure ** result,
1929 const GstStructure * simplify, GstStructure * compare)
1932 UnionField field = { 0, {0,}, NULL };
1934 /* try to subtract to get a real subset */
1935 if (gst_caps_structure_subtract (&list, simplify, compare)) {
1936 if (list == NULL) { /* no result */
1939 } else if (list->next == NULL) { /* one result */
1940 *result = list->data;
1941 g_slist_free (list);
1943 } else { /* multiple results */
1944 g_slist_foreach (list, (GFunc) gst_structure_free, NULL);
1945 g_slist_free (list);
1950 /* try to union both structs */
1951 field.compare = compare;
1952 if (gst_structure_foreach ((GstStructure *) simplify,
1953 gst_caps_structure_figure_out_union, &field)) {
1954 gboolean ret = FALSE;
1956 /* now we know all of simplify's fields are the same in compare
1957 * but at most one field: field.name */
1958 if (G_IS_VALUE (&field.value)) {
1959 if (gst_structure_n_fields (simplify) == gst_structure_n_fields (compare)) {
1960 gst_structure_id_set_value (compare, field.name, &field.value);
1964 g_value_unset (&field.value);
1965 } else if (gst_structure_n_fields (simplify) <=
1966 gst_structure_n_fields (compare)) {
1967 /* compare is just more specific, will be optimized away later */
1968 /* FIXME: do this here? */
1969 GST_LOG ("found a case that will be optimized later.");
1971 gchar *one = gst_structure_to_string (simplify);
1972 gchar *two = gst_structure_to_string (compare);
1975 ("caps mismatch: structures %s and %s claim to be possible to unify, but aren't",
1987 gst_caps_switch_structures (GstCaps * caps, GstStructure * old,
1988 GstStructure * new, gint i)
1990 gst_structure_set_parent_refcount (old, NULL);
1991 gst_structure_free (old);
1992 gst_structure_set_parent_refcount (new, &caps->refcount);
1993 g_ptr_array_index (caps->structs, i) = new;
1997 * gst_caps_do_simplify:
1998 * @caps: a #GstCaps to simplify
2000 * Modifies the given @caps inplace into a representation that represents the
2001 * same set of formats, but in a simpler form. Component structures that are
2002 * identical are merged. Component structures that have values that can be
2003 * merged are also merged.
2005 * Returns: TRUE, if the caps could be simplified
2008 gst_caps_do_simplify (GstCaps * caps)
2010 GstStructure *simplify, *compare, *result = NULL;
2012 gboolean changed = FALSE;
2014 g_return_val_if_fail (caps != NULL, FALSE);
2015 g_return_val_if_fail (IS_WRITABLE (caps), FALSE);
2017 if (gst_caps_get_size (caps) < 2)
2020 g_ptr_array_sort (caps->structs, gst_caps_compare_structures);
2022 start = caps->structs->len - 1;
2023 for (i = caps->structs->len - 1; i >= 0; i--) {
2024 simplify = gst_caps_get_structure_unchecked (caps, i);
2025 if (gst_structure_get_name_id (simplify) !=
2026 gst_structure_get_name_id (gst_caps_get_structure_unchecked (caps,
2029 for (j = start; j >= 0; j--) {
2032 compare = gst_caps_get_structure_unchecked (caps, j);
2033 if (gst_structure_get_name_id (simplify) !=
2034 gst_structure_get_name_id (compare)) {
2037 if (gst_caps_structure_simplify (&result, simplify, compare)) {
2039 gst_caps_switch_structures (caps, simplify, result, i);
2042 gst_caps_remove_structure (caps, i);
2054 /* gst_caps_do_simplify (caps); */
2060 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
2062 * gst_caps_save_thyself:
2063 * @caps: a #GstCaps structure
2064 * @parent: a XML parent node
2066 * Serializes a #GstCaps to XML and adds it as a child node of @parent.
2068 * Returns: a XML node pointer
2071 gst_caps_save_thyself (const GstCaps * caps, xmlNodePtr parent)
2073 char *s = gst_caps_to_string (caps);
2075 xmlNewChild (parent, NULL, (xmlChar *) "caps", (xmlChar *) s);
2081 * gst_caps_load_thyself:
2082 * @parent: a XML node
2084 * Creates a #GstCaps from its XML serialization.
2086 * Returns: a new #GstCaps structure
2089 gst_caps_load_thyself (xmlNodePtr parent)
2091 if (strcmp ("caps", (char *) parent->name) == 0) {
2092 return gst_caps_from_string ((gchar *) xmlNodeGetContent (parent));
2103 * @caps: (inout) (transfer full): a pointer to #GstCaps
2104 * @newcaps: a #GstCaps to replace *caps
2106 * Replaces *caps with @newcaps. Unrefs the #GstCaps in the location
2107 * pointed to by @caps, if applicable, then modifies @caps to point to
2108 * @newcaps. An additional ref on @newcaps is taken.
2110 * This function does not take any locks so you might want to lock
2111 * the object owning @caps pointer.
2114 gst_caps_replace (GstCaps ** caps, GstCaps * newcaps)
2118 g_return_if_fail (caps != NULL);
2122 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p, %p -> %p", caps, oldcaps, newcaps);
2124 if (newcaps != oldcaps) {
2126 gst_caps_ref (newcaps);
2131 gst_caps_unref (oldcaps);
2136 * gst_caps_to_string:
2139 * Converts @caps to a string representation. This string representation
2140 * can be converted back to a #GstCaps by gst_caps_from_string().
2142 * For debugging purposes its easier to do something like this:
2144 * GST_LOG ("caps are %" GST_PTR_FORMAT, caps);
2146 * This prints the caps in human readble form.
2148 * Returns: (transfer full): a newly allocated string representing @caps.
2151 gst_caps_to_string (const GstCaps * caps)
2153 guint i, slen, clen;
2156 /* NOTE: This function is potentially called by the debug system,
2157 * so any calls to gst_log() (and GST_DEBUG(), GST_LOG(), etc.)
2158 * should be careful to avoid recursion. This includes any functions
2159 * called by gst_caps_to_string. In particular, calls should
2160 * not use the GST_PTR_FORMAT extension. */
2163 return g_strdup ("NULL");
2165 if (CAPS_IS_ANY (caps)) {
2166 return g_strdup ("ANY");
2168 if (CAPS_IS_EMPTY_SIMPLE (caps)) {
2169 return g_strdup ("EMPTY");
2172 /* estimate a rough string length to avoid unnecessary reallocs in GString */
2174 clen = caps->structs->len;
2175 for (i = 0; i < clen; i++) {
2177 STRUCTURE_ESTIMATED_STRING_LEN (gst_caps_get_structure_unchecked (caps,
2181 s = g_string_sized_new (slen);
2182 for (i = 0; i < clen; i++) {
2183 GstStructure *structure;
2186 /* ';' is now added by gst_structure_to_string */
2187 g_string_append_c (s, ' ');
2190 structure = gst_caps_get_structure_unchecked (caps, i);
2191 priv_gst_structure_append_to_gstring (structure, s);
2193 if (s->len && s->str[s->len - 1] == ';') {
2194 /* remove latest ';' */
2195 s->str[--s->len] = '\0';
2197 return g_string_free (s, FALSE);
2201 gst_caps_from_string_inplace (GstCaps * caps, const gchar * string)
2203 GstStructure *structure;
2206 if (strcmp ("ANY", string) == 0) {
2207 caps->flags = GST_CAPS_FLAGS_ANY;
2210 if (strcmp ("EMPTY", string) == 0) {
2214 structure = gst_structure_from_string (string, &s);
2215 if (structure == NULL) {
2218 gst_caps_append_structure_unchecked (caps, structure);
2222 while (g_ascii_isspace (*s))
2227 structure = gst_structure_from_string (s, &s);
2228 if (structure == NULL) {
2231 gst_caps_append_structure_unchecked (caps, structure);
2239 * gst_caps_from_string:
2240 * @string: a string to convert to #GstCaps
2242 * Converts @caps from a string representation.
2244 * Returns: (transfer full): a newly allocated #GstCaps
2247 gst_caps_from_string (const gchar * string)
2251 g_return_val_if_fail (string, FALSE);
2253 caps = gst_caps_new_empty ();
2254 if (gst_caps_from_string_inplace (caps, string)) {
2257 gst_caps_unref (caps);
2263 gst_caps_transform_to_string (const GValue * src_value, GValue * dest_value)
2265 g_return_if_fail (G_IS_VALUE (src_value));
2266 g_return_if_fail (G_IS_VALUE (dest_value));
2267 g_return_if_fail (G_VALUE_HOLDS (src_value, GST_TYPE_CAPS));
2268 g_return_if_fail (G_VALUE_HOLDS (dest_value, G_TYPE_STRING)
2269 || G_VALUE_HOLDS (dest_value, G_TYPE_POINTER));
2271 dest_value->data[0].v_pointer =
2272 gst_caps_to_string (src_value->data[0].v_pointer);
2276 gst_caps_copy_conditional (GstCaps * src)
2279 return gst_caps_ref (src);