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: 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: 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: 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);
228 gst_caps_append_structure_unchecked (caps, structure);
235 * @struct1: the first structure to add
236 * @...: additional structures to add
238 * Creates a new #GstCaps and adds all the structures listed as
239 * arguments. The list must be NULL-terminated. The structures
240 * are not copied; the returned #GstCaps owns the structures.
242 * Returns: the new #GstCaps
245 gst_caps_new_full (GstStructure * struct1, ...)
250 va_start (var_args, struct1);
251 caps = gst_caps_new_full_valist (struct1, var_args);
258 * gst_caps_new_full_valist:
259 * @structure: the first structure to add
260 * @var_args: additional structures to add
262 * Creates a new #GstCaps and adds all the structures listed as
263 * arguments. The list must be NULL-terminated. The structures
264 * are not copied; the returned #GstCaps owns the structures.
266 * Returns: the new #GstCaps
269 gst_caps_new_full_valist (GstStructure * structure, va_list var_args)
273 caps = gst_caps_new_empty ();
276 gst_caps_append_structure_unchecked (caps, structure);
277 structure = va_arg (var_args, GstStructure *);
285 * @caps: the #GstCaps to copy
287 * Creates a new #GstCaps as a copy of the old @caps. The new caps will have a
288 * refcount of 1, owned by the caller. The structures are copied as well.
290 * Note that this function is the semantic equivalent of a gst_caps_ref()
291 * followed by a gst_caps_make_writable(). If you only want to hold on to a
292 * reference to the data, you should use gst_caps_ref().
294 * When you are finished with the caps, call gst_caps_unref() on it.
296 * Returns: the new #GstCaps
299 gst_caps_copy (const GstCaps * caps)
302 GstStructure *structure;
305 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
307 newcaps = gst_caps_new_empty ();
308 newcaps->flags = caps->flags;
309 n = caps->structs->len;
311 for (i = 0; i < n; i++) {
312 structure = gst_caps_get_structure_unchecked (caps, i);
313 gst_caps_append_structure_unchecked (newcaps,
314 gst_structure_copy (structure));
321 _gst_caps_free (GstCaps * caps)
323 GstStructure *structure;
326 /* The refcount must be 0, but since we're only called by gst_caps_unref,
327 * don't bother testing. */
328 len = caps->structs->len;
329 /* This can be used to get statistics about caps sizes */
330 /*GST_CAT_INFO (GST_CAT_CAPS, "caps size: %d", len); */
331 for (i = 0; i < len; i++) {
332 structure = (GstStructure *) gst_caps_get_structure_unchecked (caps, i);
333 gst_structure_set_parent_refcount (structure, NULL);
334 gst_structure_free (structure);
336 g_ptr_array_free (caps->structs, TRUE);
338 memset (caps, 0xff, sizeof (GstCaps));
341 #ifdef DEBUG_REFCOUNT
342 GST_CAT_LOG (GST_CAT_CAPS, "freeing caps %p", caps);
344 g_slice_free (GstCaps, caps);
348 * gst_caps_make_writable:
349 * @caps: the #GstCaps to make writable
351 * Returns a writable copy of @caps.
353 * If there is only one reference count on @caps, the caller must be the owner,
354 * and so this function will return the caps object unchanged. If on the other
355 * hand there is more than one reference on the object, a new caps object will
356 * be returned. The caller's reference on @caps will be removed, and instead the
357 * caller will own a reference to the returned object.
359 * In short, this function unrefs the caps in the argument and refs the caps
360 * that it returns. Don't access the argument after calling this function. See
361 * also: gst_caps_ref().
363 * Returns: the same #GstCaps object.
366 gst_caps_make_writable (GstCaps * caps)
370 g_return_val_if_fail (caps != NULL, NULL);
372 /* we are the only instance reffing this caps */
373 if (IS_WRITABLE (caps))
377 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy caps");
378 copy = gst_caps_copy (caps);
379 gst_caps_unref (caps);
386 * @caps: the #GstCaps to reference
388 * Add a reference to a #GstCaps object.
390 * From this point on, until the caller calls gst_caps_unref() or
391 * gst_caps_make_writable(), it is guaranteed that the caps object will not
392 * change. This means its structures won't change, etc. To use a #GstCaps
393 * object, you must always have a refcount on it -- either the one made
394 * implicitly by e.g. gst_caps_new_simple(), or via taking one explicitly with
397 * Returns: the same #GstCaps object.
400 gst_caps_ref (GstCaps * caps)
402 g_return_val_if_fail (caps != NULL, NULL);
404 #ifdef DEBUG_REFCOUNT
405 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p %d->%d", caps,
406 GST_CAPS_REFCOUNT_VALUE (caps), GST_CAPS_REFCOUNT_VALUE (caps) + 1);
408 g_return_val_if_fail (GST_CAPS_REFCOUNT_VALUE (caps), NULL);
410 g_atomic_int_inc (&caps->refcount);
417 * @caps: the #GstCaps to unref
419 * Unref a #GstCaps and and free all its structures and the
420 * structures' values when the refcount reaches 0.
423 gst_caps_unref (GstCaps * caps)
425 g_return_if_fail (caps != NULL);
427 #ifdef DEBUG_REFCOUNT
428 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p %d->%d", caps,
429 GST_CAPS_REFCOUNT_VALUE (caps), GST_CAPS_REFCOUNT_VALUE (caps) - 1);
432 g_return_if_fail (GST_CAPS_REFCOUNT_VALUE (caps));
434 /* if we ended up with the refcount at zero, free the caps */
435 if (G_UNLIKELY (g_atomic_int_dec_and_test (&caps->refcount)))
436 _gst_caps_free (caps);
440 gst_static_caps_get_type (void)
442 static GType staticcaps_type = 0;
444 if (G_UNLIKELY (staticcaps_type == 0)) {
445 staticcaps_type = g_pointer_type_register_static ("GstStaticCaps");
447 return staticcaps_type;
452 * gst_static_caps_get:
453 * @static_caps: the #GstStaticCaps to convert
455 * Converts a #GstStaticCaps to a #GstCaps.
457 * Returns: A pointer to the #GstCaps. Unref after usage. Since the
458 * core holds an additional ref to the returned caps,
459 * use gst_caps_make_writable() on the returned caps to modify it.
462 gst_static_caps_get (GstStaticCaps * static_caps)
466 g_return_val_if_fail (static_caps != NULL, NULL);
468 caps = (GstCaps *) static_caps;
470 /* refcount is 0 when we need to convert */
471 if (G_UNLIKELY (g_atomic_int_get (&caps->refcount) == 0)) {
475 G_LOCK (static_caps_lock);
476 /* check if other thread already updated */
477 if (G_UNLIKELY (g_atomic_int_get (&caps->refcount)))
480 string = static_caps->string;
482 if (G_UNLIKELY (string == NULL))
485 GST_CAT_LOG (GST_CAT_CAPS, "creating %p", static_caps);
487 /* we construct the caps on the stack, then copy over the struct into our
488 * real caps, refcount last. We do this because we must leave the refcount
489 * of the result caps to 0 so that other threads don't run away with the
490 * caps while we are constructing it. */
491 temp.type = GST_TYPE_CAPS;
493 temp.structs = g_ptr_array_new ();
495 /* initialize the caps to a refcount of 1 so the caps can be writable for
496 * the next statement */
499 /* convert to string */
500 if (G_UNLIKELY (!gst_caps_from_string_inplace (&temp, string)))
501 g_critical ("Could not convert static caps \"%s\"", string);
503 /* now copy stuff over to the real caps. */
504 caps->type = temp.type;
505 caps->flags = temp.flags;
506 caps->structs = temp.structs;
507 /* and bump the refcount so other threads can now read */
508 g_atomic_int_set (&caps->refcount, 1);
510 GST_CAT_LOG (GST_CAT_CAPS, "created %p", static_caps);
512 G_UNLOCK (static_caps_lock);
514 /* ref the caps, makes it not writable */
522 G_UNLOCK (static_caps_lock);
523 g_warning ("static caps %p string is NULL", static_caps);
530 static GstStructure *
531 gst_caps_remove_and_get_structure (GstCaps * caps, guint idx)
533 /* don't use index_fast, gst_caps_do_simplify relies on the order */
534 GstStructure *s = g_ptr_array_remove_index (caps->structs, idx);
536 gst_structure_set_parent_refcount (s, NULL);
541 * gst_caps_steal_structure:
542 * @caps: the #GstCaps to retrieve from
543 * @index: Index of the structure to retrieve
545 * Retrieves the stucture with the given index from the list of structures
546 * contained in @caps. The caller becomes the owner of the returned structure.
548 * Returns: a pointer to the #GstStructure corresponding to @index.
553 gst_caps_steal_structure (GstCaps * caps, guint index)
555 g_return_val_if_fail (caps != NULL, NULL);
556 g_return_val_if_fail (IS_WRITABLE (caps), NULL);
558 if (G_UNLIKELY (index >= caps->structs->len))
561 return gst_caps_remove_and_get_structure (caps, index);
565 gst_structure_is_equal_foreach (GQuark field_id, const GValue * val2,
568 GstStructure *struct1 = (GstStructure *) data;
569 const GValue *val1 = gst_structure_id_get_value (struct1, field_id);
571 if (G_UNLIKELY (val1 == NULL))
573 if (gst_value_compare (val1, val2) == GST_VALUE_EQUAL) {
581 gst_caps_structure_is_subset_field (GQuark field_id, const GValue * value,
584 GstStructure *subtract_from = user_data;
585 GValue subtraction = { 0, };
588 if (!(other = gst_structure_id_get_value (subtract_from, field_id)))
589 /* field is missing in one set */
592 /* equal values are subset */
593 if (gst_value_compare (other, value) == GST_VALUE_EQUAL)
601 * -> 1 - [1,2] = empty
605 * -> [1,2] - [1,3] = empty
609 * -> {1,3} - {1,2} = 3
612 * First caps subtraction needs to return a non-empty set, second
613 * subtractions needs to give en empty set.
615 if (gst_value_subtract (&subtraction, other, value)) {
616 g_value_unset (&subtraction);
617 /* !empty result, swapping must be empty */
618 if (!gst_value_subtract (&subtraction, value, other))
621 g_value_unset (&subtraction);
627 gst_caps_structure_is_subset (const GstStructure * minuend,
628 const GstStructure * subtrahend)
630 if ((minuend->name != subtrahend->name) ||
631 (gst_structure_n_fields (minuend) !=
632 gst_structure_n_fields (subtrahend))) {
636 return gst_structure_foreach ((GstStructure *) subtrahend,
637 gst_caps_structure_is_subset_field, (gpointer) minuend);
642 * @caps1: the #GstCaps that will be appended to
643 * @caps2: the #GstCaps to append
645 * Appends the structures contained in @caps2 to @caps1. The structures in
646 * @caps2 are not copied -- they are transferred to @caps1, and then @caps2 is
647 * freed. If either caps is ANY, the resulting caps will be ANY.
650 gst_caps_append (GstCaps * caps1, GstCaps * caps2)
652 GstStructure *structure;
655 g_return_if_fail (GST_IS_CAPS (caps1));
656 g_return_if_fail (GST_IS_CAPS (caps2));
657 g_return_if_fail (IS_WRITABLE (caps1));
658 g_return_if_fail (IS_WRITABLE (caps2));
663 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))) {
664 /* FIXME: this leaks */
665 caps1->flags |= GST_CAPS_FLAGS_ANY;
666 for (i = caps2->structs->len - 1; i >= 0; i--) {
667 structure = gst_caps_remove_and_get_structure (caps2, i);
668 gst_structure_free (structure);
671 for (i = caps2->structs->len; i; i--) {
672 structure = gst_caps_remove_and_get_structure (caps2, 0);
673 gst_caps_append_structure_unchecked (caps1, structure);
676 gst_caps_unref (caps2); /* guaranteed to free it */
681 * @caps1: the #GstCaps that will take the new entries
682 * @caps2: the #GstCaps to merge in
684 * Appends the structures contained in @caps2 to @caps1 if they are not yet
685 * expressed by @caps1. The structures in @caps2 are not copied -- they are
686 * transferred to @caps1, and then @caps2 is freed.
687 * If either caps is ANY, the resulting caps will be ANY.
692 gst_caps_merge (GstCaps * caps1, GstCaps * caps2)
694 GstStructure *structure;
697 g_return_if_fail (GST_IS_CAPS (caps1));
698 g_return_if_fail (GST_IS_CAPS (caps2));
699 g_return_if_fail (IS_WRITABLE (caps1));
700 g_return_if_fail (IS_WRITABLE (caps2));
705 if (G_UNLIKELY (CAPS_IS_ANY (caps1))) {
706 for (i = caps2->structs->len - 1; i >= 0; i--) {
707 structure = gst_caps_remove_and_get_structure (caps2, i);
708 gst_structure_free (structure);
710 } else if (G_UNLIKELY (CAPS_IS_ANY (caps2))) {
711 caps1->flags |= GST_CAPS_FLAGS_ANY;
712 for (i = caps1->structs->len - 1; i >= 0; i--) {
713 structure = gst_caps_remove_and_get_structure (caps1, i);
714 gst_structure_free (structure);
717 for (i = caps2->structs->len; i; i--) {
718 structure = gst_caps_remove_and_get_structure (caps2, 0);
719 gst_caps_merge_structure (caps1, structure);
722 GstCaps *com = gst_caps_intersect (caps1, caps2);
723 GstCaps *add = gst_caps_subtract (caps2, com);
725 GST_DEBUG ("common : %d", gst_caps_get_size (com));
726 GST_DEBUG ("adding : %d", gst_caps_get_size (add));
727 gst_caps_append (caps1, add);
728 gst_caps_unref (com);
731 gst_caps_unref (caps2); /* guaranteed to free it */
735 * gst_caps_append_structure:
736 * @caps: the #GstCaps that will be appended to
737 * @structure: the #GstStructure to append
739 * Appends @structure to @caps. The structure is not copied; @caps
740 * becomes the owner of @structure.
743 gst_caps_append_structure (GstCaps * caps, GstStructure * structure)
745 g_return_if_fail (GST_IS_CAPS (caps));
746 g_return_if_fail (IS_WRITABLE (caps));
748 if (G_LIKELY (structure)) {
749 g_return_if_fail (structure->parent_refcount == NULL);
752 STRUCTURE_POISON (structure);
755 gst_caps_append_structure_unchecked (caps, structure);
760 * gst_caps_remove_structure:
761 * @caps: the #GstCaps to remove from
762 * @idx: Index of the structure to remove
764 * removes the stucture with the given index from the list of structures
765 * contained in @caps.
768 gst_caps_remove_structure (GstCaps * caps, guint idx)
770 GstStructure *structure;
772 g_return_if_fail (caps != NULL);
773 g_return_if_fail (idx <= gst_caps_get_size (caps));
774 g_return_if_fail (IS_WRITABLE (caps));
776 structure = gst_caps_remove_and_get_structure (caps, idx);
777 gst_structure_free (structure);
781 * gst_caps_merge_structure:
782 * @caps: the #GstCaps that will the the new structure
783 * @structure: the #GstStructure to merge
785 * Appends @structure to @caps if its not already expressed by @caps. The
786 * structure is not copied; @caps becomes the owner of @structure.
789 gst_caps_merge_structure (GstCaps * caps, GstStructure * structure)
791 g_return_if_fail (GST_IS_CAPS (caps));
792 g_return_if_fail (IS_WRITABLE (caps));
794 if (G_LIKELY (structure)) {
795 GstStructure *structure1;
797 gboolean unique = TRUE;
799 g_return_if_fail (structure->parent_refcount == NULL);
802 STRUCTURE_POISON (structure);
805 /* check each structure */
806 for (i = caps->structs->len - 1; i >= 0; i--) {
807 structure1 = gst_caps_get_structure_unchecked (caps, i);
808 /* if structure is a subset of structure1, then skip it */
809 if (gst_caps_structure_is_subset (structure1, structure)) {
815 gst_caps_append_structure_unchecked (caps, structure);
817 gst_structure_free (structure);
826 * Gets the number of structures contained in @caps.
828 * Returns: the number of structures that @caps contains
831 gst_caps_get_size (const GstCaps * caps)
833 g_return_val_if_fail (GST_IS_CAPS (caps), 0);
835 return caps->structs->len;
839 * gst_caps_get_structure:
841 * @index: the index of the structure
843 * Finds the structure in @caps that has the index @index, and
846 * WARNING: This function takes a const GstCaps *, but returns a
847 * non-const GstStructure *. This is for programming convenience --
848 * the caller should be aware that structures inside a constant
849 * #GstCaps should not be modified. However, if you know the caps
850 * are writable, either because you have just copied them or made
851 * them writable with gst_caps_make_writable(), you may modify the
852 * structure returned in the usual way, e.g. with functions like
853 * gst_structure_set().
855 * You do not need to free or unref the structure returned, it
856 * belongs to the #GstCaps.
858 * Returns: a pointer to the #GstStructure corresponding to @index
861 gst_caps_get_structure (const GstCaps * caps, guint index)
863 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
864 g_return_val_if_fail (index < caps->structs->len, NULL);
866 return gst_caps_get_structure_unchecked (caps, index);
871 * @caps: the #GstCaps to copy
872 * @nth: the nth structure to copy
874 * Creates a new #GstCaps and appends a copy of the nth structure
875 * contained in @caps.
877 * Returns: the new #GstCaps
880 gst_caps_copy_nth (const GstCaps * caps, guint nth)
883 GstStructure *structure;
885 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
887 newcaps = gst_caps_new_empty ();
888 newcaps->flags = caps->flags;
890 if (G_LIKELY (caps->structs->len > nth)) {
891 structure = gst_caps_get_structure_unchecked (caps, nth);
892 gst_caps_append_structure_unchecked (newcaps,
893 gst_structure_copy (structure));
901 * @caps: the #GstCaps to truncate
903 * Destructively discard all but the first structure from @caps. Useful when
904 * fixating. @caps must be writable.
907 gst_caps_truncate (GstCaps * caps)
911 g_return_if_fail (GST_IS_CAPS (caps));
912 g_return_if_fail (IS_WRITABLE (caps));
914 i = caps->structs->len - 1;
917 gst_caps_remove_structure (caps, i--);
921 * gst_caps_set_value:
922 * @caps: a writable caps
923 * @field: name of the field to set
924 * @value: value to set the field to
926 * Sets the given @field on all structures of @caps to the given @value.
927 * This is a convenience function for calling gst_structure_set_value() on
928 * all structures of @caps.
933 gst_caps_set_value (GstCaps * caps, const char *field, const GValue * value)
937 g_return_if_fail (GST_IS_CAPS (caps));
938 g_return_if_fail (IS_WRITABLE (caps));
939 g_return_if_fail (field != NULL);
940 g_return_if_fail (G_IS_VALUE (value));
942 len = caps->structs->len;
943 for (i = 0; i < len; i++) {
944 GstStructure *structure = gst_caps_get_structure_unchecked (caps, i);
945 gst_structure_set_value (structure, field, value);
950 * gst_caps_set_simple_valist:
951 * @caps: the #GstCaps to set
952 * @field: first field to set
953 * @varargs: additional parameters
955 * Sets fields in a #GstCaps. The arguments must be passed in the same
956 * manner as gst_structure_set(), and be NULL-terminated.
957 * <note>Prior to GStreamer version 0.10.26, this function failed when
958 * @caps was not simple. If your code needs to work with those versions
959 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
960 * is %TRUE for @caps.</note>
963 gst_caps_set_simple_valist (GstCaps * caps, const char *field, va_list varargs)
965 GValue value = { 0, };
967 g_return_if_fail (GST_IS_CAPS (caps));
968 g_return_if_fail (IS_WRITABLE (caps));
974 type = va_arg (varargs, GType);
976 if (G_UNLIKELY (type == G_TYPE_DATE)) {
977 g_warning ("Don't use G_TYPE_DATE, use GST_TYPE_DATE instead\n");
978 type = GST_TYPE_DATE;
980 #if GLIB_CHECK_VERSION(2,23,3)
981 G_VALUE_COLLECT_INIT (&value, type, varargs, 0, &err);
983 g_value_init (&value, type);
984 G_VALUE_COLLECT (&value, varargs, 0, &err);
986 if (G_UNLIKELY (err)) {
987 g_critical ("%s", err);
991 gst_caps_set_value (caps, field, &value);
993 g_value_unset (&value);
995 field = va_arg (varargs, const gchar *);
1000 * gst_caps_set_simple:
1001 * @caps: the #GstCaps to set
1002 * @field: first field to set
1003 * @...: additional parameters
1005 * Sets fields in a #GstCaps. The arguments must be passed in the same
1006 * manner as gst_structure_set(), and be NULL-terminated.
1007 * <note>Prior to GStreamer version 0.10.26, this function failed when
1008 * @caps was not simple. If your code needs to work with those versions
1009 * of GStreamer, you may only call this function when GST_CAPS_IS_SIMPLE()
1010 * is %TRUE for @caps.</note>
1013 gst_caps_set_simple (GstCaps * caps, const char *field, ...)
1017 g_return_if_fail (GST_IS_CAPS (caps));
1018 g_return_if_fail (IS_WRITABLE (caps));
1020 va_start (var_args, field);
1021 gst_caps_set_simple_valist (caps, field, var_args);
1029 * @caps: the #GstCaps to test
1031 * Determines if @caps represents any media format.
1033 * Returns: TRUE if @caps represents any format.
1036 gst_caps_is_any (const GstCaps * caps)
1038 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1040 return (CAPS_IS_ANY (caps));
1044 * gst_caps_is_empty:
1045 * @caps: the #GstCaps to test
1047 * Determines if @caps represents no media formats.
1049 * Returns: TRUE if @caps represents no formats.
1052 gst_caps_is_empty (const GstCaps * caps)
1054 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1056 if (CAPS_IS_ANY (caps))
1059 return CAPS_IS_EMPTY_SIMPLE (caps);
1063 gst_caps_is_fixed_foreach (GQuark field_id, const GValue * value,
1066 return gst_value_is_fixed (value);
1070 * gst_caps_is_fixed:
1071 * @caps: the #GstCaps to test
1073 * Fixed #GstCaps describe exactly one format, that is, they have exactly
1074 * one structure, and each field in the structure describes a fixed type.
1075 * Examples of non-fixed types are GST_TYPE_INT_RANGE and GST_TYPE_LIST.
1077 * Returns: TRUE if @caps is fixed
1080 gst_caps_is_fixed (const GstCaps * caps)
1082 GstStructure *structure;
1084 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
1086 if (caps->structs->len != 1)
1089 structure = gst_caps_get_structure_unchecked (caps, 0);
1091 return gst_structure_foreach (structure, gst_caps_is_fixed_foreach, NULL);
1095 * gst_caps_is_equal_fixed:
1096 * @caps1: the #GstCaps to test
1097 * @caps2: the #GstCaps to test
1099 * Tests if two #GstCaps are equal. This function only works on fixed
1102 * Returns: TRUE if the arguments represent the same format
1105 gst_caps_is_equal_fixed (const GstCaps * caps1, const GstCaps * caps2)
1107 GstStructure *struct1, *struct2;
1109 g_return_val_if_fail (gst_caps_is_fixed (caps1), FALSE);
1110 g_return_val_if_fail (gst_caps_is_fixed (caps2), FALSE);
1112 struct1 = gst_caps_get_structure_unchecked (caps1, 0);
1113 struct2 = gst_caps_get_structure_unchecked (caps2, 0);
1115 if (struct1->name != struct2->name) {
1118 if (struct1->fields->len != struct2->fields->len) {
1122 return gst_structure_foreach (struct1, gst_structure_is_equal_foreach,
1127 * gst_caps_is_always_compatible:
1128 * @caps1: the #GstCaps to test
1129 * @caps2: the #GstCaps to test
1131 * A given #GstCaps structure is always compatible with another if
1132 * every media format that is in the first is also contained in the
1133 * second. That is, @caps1 is a subset of @caps2.
1135 * Returns: TRUE if @caps1 is a subset of @caps2.
1138 gst_caps_is_always_compatible (const GstCaps * caps1, const GstCaps * caps2)
1140 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1141 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1143 return gst_caps_is_subset (caps1, caps2);
1147 * gst_caps_is_subset:
1148 * @subset: a #GstCaps
1149 * @superset: a potentially greater #GstCaps
1151 * Checks if all caps represented by @subset are also represented by @superset.
1152 * <note>This function does not work reliably if optional properties for caps
1153 * are included on one caps and omitted on the other.</note>
1155 * Returns: %TRUE if @subset is a subset of @superset
1158 gst_caps_is_subset (const GstCaps * subset, const GstCaps * superset)
1163 g_return_val_if_fail (subset != NULL, FALSE);
1164 g_return_val_if_fail (superset != NULL, FALSE);
1166 if (CAPS_IS_EMPTY (subset) || CAPS_IS_ANY (superset))
1168 if (CAPS_IS_ANY (subset) || CAPS_IS_EMPTY (superset))
1171 caps = gst_caps_subtract (subset, superset);
1172 ret = CAPS_IS_EMPTY_SIMPLE (caps);
1173 gst_caps_unref (caps);
1178 * gst_caps_is_equal:
1179 * @caps1: a #GstCaps
1180 * @caps2: another #GstCaps
1182 * Checks if the given caps represent the same set of caps.
1183 * <note>This function does not work reliably if optional properties for caps
1184 * are included on one caps and omitted on the other.</note>
1186 * This function deals correctly with passing NULL for any of the caps.
1188 * Returns: TRUE if both caps are equal.
1191 gst_caps_is_equal (const GstCaps * caps1, const GstCaps * caps2)
1193 /* FIXME 0.11: NULL pointers are no valid Caps but indicate an error
1194 * So there should be an assertion that caps1 and caps2 != NULL */
1196 /* NULL <-> NULL is allowed here */
1197 if (G_UNLIKELY (caps1 == caps2))
1200 /* one of them NULL => they are different (can't be both NULL because
1201 * we checked that above) */
1202 if (G_UNLIKELY (caps1 == NULL || caps2 == NULL))
1205 if (G_UNLIKELY (gst_caps_is_fixed (caps1) && gst_caps_is_fixed (caps2)))
1206 return gst_caps_is_equal_fixed (caps1, caps2);
1208 return gst_caps_is_subset (caps1, caps2) && gst_caps_is_subset (caps2, caps1);
1211 /* intersect operation */
1216 const GstStructure *intersect;
1221 gst_caps_structure_intersect_field1 (GQuark id, const GValue * val1,
1224 IntersectData *idata = (IntersectData *) data;
1225 const GValue *val2 = gst_structure_id_get_value (idata->intersect, id);
1227 if (G_UNLIKELY (val2 == NULL)) {
1228 gst_structure_id_set_value (idata->dest, id, val1);
1230 GValue dest_value = { 0 };
1231 if (gst_value_intersect (&dest_value, val1, val2)) {
1232 gst_structure_id_set_value (idata->dest, id, &dest_value);
1233 g_value_unset (&dest_value);
1242 gst_caps_structure_intersect_field2 (GQuark id, const GValue * val1,
1245 IntersectData *idata = (IntersectData *) data;
1246 const GValue *val2 = gst_structure_id_get_value (idata->intersect, id);
1248 if (G_UNLIKELY (val2 == NULL)) {
1249 gst_structure_id_set_value (idata->dest, id, val1);
1254 static GstStructure *
1255 gst_caps_structure_intersect (const GstStructure * struct1,
1256 const GstStructure * struct2)
1260 g_assert (struct1 != NULL);
1261 g_assert (struct2 != NULL);
1263 if (G_UNLIKELY (struct1->name != struct2->name))
1266 /* copy fields from struct1 which we have not in struct2 to target
1267 * intersect if we have the field in both */
1268 data.dest = gst_structure_id_empty_new (struct1->name);
1269 data.intersect = struct2;
1270 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct1,
1271 gst_caps_structure_intersect_field1, &data)))
1274 /* copy fields from struct2 which we have not in struct1 to target */
1275 data.intersect = struct1;
1276 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct2,
1277 gst_caps_structure_intersect_field2, &data)))
1283 gst_structure_free (data.dest);
1288 gst_caps_structure_can_intersect_field (GQuark id, const GValue * val1,
1291 GstStructure *other = (GstStructure *) data;
1292 const GValue *val2 = gst_structure_id_get_value (other, id);
1294 if (G_LIKELY (val2)) {
1295 if (!gst_value_can_intersect (val1, val2)) {
1298 gint eq = gst_value_compare (val1, val2);
1300 if (eq == GST_VALUE_UNORDERED) {
1301 /* we need to try interseting */
1302 GValue dest_value = { 0 };
1303 if (gst_value_intersect (&dest_value, val1, val2)) {
1304 g_value_unset (&dest_value);
1308 } else if (eq != GST_VALUE_EQUAL) {
1317 gst_caps_structure_can_intersect (const GstStructure * struct1,
1318 const GstStructure * struct2)
1320 g_assert (struct1 != NULL);
1321 g_assert (struct2 != NULL);
1323 if (G_UNLIKELY (struct1->name != struct2->name))
1326 /* tries to intersect if we have the field in both */
1327 if (G_UNLIKELY (!gst_structure_foreach ((GstStructure *) struct1,
1328 gst_caps_structure_can_intersect_field, (gpointer) struct2)))
1335 * gst_caps_can_intersect:
1336 * @caps1: a #GstCaps to intersect
1337 * @caps2: a #GstCaps to intersect
1339 * Tries intersecting @caps1 and @caps2 and reports wheter the result would not
1342 * Returns: %TRUE if intersection would be not empty
1347 gst_caps_can_intersect (const GstCaps * caps1, const GstCaps * caps2)
1349 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1350 guint j, k, len1, len2;
1351 GstStructure *struct1;
1352 GstStructure *struct2;
1354 g_return_val_if_fail (GST_IS_CAPS (caps1), FALSE);
1355 g_return_val_if_fail (GST_IS_CAPS (caps2), FALSE);
1357 /* caps are exactly the same pointers */
1358 if (G_UNLIKELY (caps1 == caps2))
1361 /* empty caps on either side, return empty */
1362 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1365 /* one of the caps is any */
1366 if (G_UNLIKELY (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2)))
1369 /* run zigzag on top line then right line, this preserves the caps order
1370 * much better than a simple loop.
1372 * This algorithm zigzags over the caps structures as demonstrated in
1373 * the folowing matrix:
1376 * +------------- total distance: +-------------
1377 * | 1 2 4 7 0 | 0 1 2 3
1378 * caps2 | 3 5 8 10 1 | 1 2 3 4
1379 * | 6 9 11 12 2 | 2 3 4 5
1381 * First we iterate over the caps1 structures (top line) intersecting
1382 * the structures diagonally down, then we iterate over the caps2
1383 * structures. The result is that the intersections are ordered based on the
1384 * sum of the indexes in the list.
1386 len1 = caps1->structs->len;
1387 len2 = caps2->structs->len;
1388 for (i = 0; i < len1 + len2 - 1; i++) {
1389 /* superset index goes from 0 to sgst_caps_structure_intersectuperset->structs->len-1 */
1390 j = MIN (i, len1 - 1);
1391 /* subset index stays 0 until i reaches superset->structs->len, then it
1392 * counts up from 1 to subset->structs->len - 1 */
1395 /* now run the diagonal line, end condition is the left or bottom
1398 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1399 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1401 if (gst_caps_structure_can_intersect (struct1, struct2)) {
1404 /* move down left */
1406 if (G_UNLIKELY (j == 0))
1407 break; /* so we don't roll back to G_MAXUINT */
1415 * gst_caps_intersect:
1416 * @caps1: a #GstCaps to intersect
1417 * @caps2: a #GstCaps to intersect
1419 * Creates a new #GstCaps that contains all the formats that are common
1420 * to both @caps1 and @caps2.
1422 * Returns: the new #GstCaps
1425 gst_caps_intersect (const GstCaps * caps1, const GstCaps * caps2)
1427 guint64 i; /* index can be up to 2 * G_MAX_UINT */
1428 guint j, k, len1, len2;
1430 GstStructure *struct1;
1431 GstStructure *struct2;
1433 GstStructure *istruct;
1435 g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
1436 g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
1438 /* caps are exactly the same pointers, just copy one caps */
1439 if (G_UNLIKELY (caps1 == caps2))
1440 return gst_caps_copy (caps1);
1442 /* empty caps on either side, return empty */
1443 if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
1444 return gst_caps_new_empty ();
1446 /* one of the caps is any, just copy the other caps */
1447 if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
1448 return gst_caps_copy (caps2);
1449 if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
1450 return gst_caps_copy (caps1);
1452 dest = gst_caps_new_empty ();
1454 /* run zigzag on top line then right line, this preserves the caps order
1455 * much better than a simple loop.
1457 * This algorithm zigzags over the caps structures as demonstrated in
1458 * the folowing matrix:
1466 * First we iterate over the caps1 structures (top line) intersecting
1467 * the structures diagonally down, then we iterate over the caps2
1470 len1 = caps1->structs->len;
1471 len2 = caps2->structs->len;
1472 for (i = 0; i < len1 + len2 - 1; i++) {
1473 /* caps1 index goes from 0 to caps1->structs->len-1 */
1474 j = MIN (i, len1 - 1);
1475 /* caps2 index stays 0 until i reaches caps1->structs->len, then it counts
1476 * up from 1 to caps2->structs->len - 1 */
1479 /* now run the diagonal line, end condition is the left or bottom
1482 struct1 = gst_caps_get_structure_unchecked (caps1, j);
1483 struct2 = gst_caps_get_structure_unchecked (caps2, k);
1485 istruct = gst_caps_structure_intersect (struct1, struct2);
1487 gst_caps_append_structure (dest, istruct);
1488 /* move down left */
1490 if (G_UNLIKELY (j == 0))
1491 break; /* so we don't roll back to G_MAXUINT */
1498 /* subtract operation */
1502 const GstStructure *subtract_from;
1508 gst_caps_structure_subtract_field (GQuark field_id, const GValue * value,
1511 SubtractionEntry *e = user_data;
1512 GValue subtraction = { 0, };
1513 const GValue *other;
1514 GstStructure *structure;
1516 other = gst_structure_id_get_value (e->subtract_from, field_id);
1520 if (!gst_value_subtract (&subtraction, other, value))
1522 if (gst_value_compare (&subtraction, other) == GST_VALUE_EQUAL) {
1523 g_value_unset (&subtraction);
1526 structure = gst_structure_copy (e->subtract_from);
1527 gst_structure_id_set_value (structure, field_id, &subtraction);
1528 g_value_unset (&subtraction);
1529 e->put_into = g_slist_prepend (e->put_into, structure);
1535 gst_caps_structure_subtract (GSList ** into, const GstStructure * minuend,
1536 const GstStructure * subtrahend)
1541 e.subtract_from = minuend;
1544 ret = gst_structure_foreach ((GstStructure *) subtrahend,
1545 gst_caps_structure_subtract_field, &e);
1551 for (walk = e.put_into; walk; walk = g_slist_next (walk)) {
1552 gst_structure_free (walk->data);
1554 g_slist_free (e.put_into);
1560 * gst_caps_subtract:
1561 * @minuend: #GstCaps to substract from
1562 * @subtrahend: #GstCaps to substract
1564 * Subtracts the @subtrahend from the @minuend.
1565 * <note>This function does not work reliably if optional properties for caps
1566 * are included on one caps and omitted on the other.</note>
1568 * Returns: the resulting caps
1571 gst_caps_subtract (const GstCaps * minuend, const GstCaps * subtrahend)
1576 GstCaps *dest = NULL, *src;
1578 g_return_val_if_fail (minuend != NULL, NULL);
1579 g_return_val_if_fail (subtrahend != NULL, NULL);
1581 if (CAPS_IS_EMPTY (minuend) || CAPS_IS_ANY (subtrahend)) {
1582 return gst_caps_new_empty ();
1584 if (CAPS_IS_EMPTY_SIMPLE (subtrahend))
1585 return gst_caps_copy (minuend);
1587 /* FIXME: Do we want this here or above?
1588 The reason we need this is that there is no definition about what
1589 ANY means for specific types, so it's not possible to reduce ANY partially
1590 You can only remove everything or nothing and that is done above.
1591 Note: there's a test that checks this behaviour. */
1592 g_return_val_if_fail (!CAPS_IS_ANY (minuend), NULL);
1593 sublen = subtrahend->structs->len;
1596 src = gst_caps_copy (minuend);
1597 for (i = 0; i < sublen; i++) {
1600 sub = gst_caps_get_structure_unchecked (subtrahend, i);
1602 gst_caps_unref (src);
1605 dest = gst_caps_new_empty ();
1606 srclen = src->structs->len;
1607 for (j = 0; j < srclen; j++) {
1608 min = gst_caps_get_structure_unchecked (src, j);
1609 if (gst_structure_get_name_id (min) == gst_structure_get_name_id (sub)) {
1612 if (gst_caps_structure_subtract (&list, min, sub)) {
1615 for (walk = list; walk; walk = g_slist_next (walk)) {
1616 gst_caps_append_structure_unchecked (dest,
1617 (GstStructure *) walk->data);
1619 g_slist_free (list);
1621 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1624 gst_caps_append_structure_unchecked (dest, gst_structure_copy (min));
1627 if (CAPS_IS_EMPTY_SIMPLE (dest)) {
1628 gst_caps_unref (src);
1633 gst_caps_unref (src);
1634 gst_caps_do_simplify (dest);
1638 /* union operation */
1641 static GstStructure *
1642 gst_caps_structure_union (const GstStructure * struct1,
1643 const GstStructure * struct2)
1647 const GstStructureField *field1;
1648 const GstStructureField *field2;
1651 /* FIXME this doesn't actually work */
1653 if (struct1->name != struct2->name)
1656 dest = gst_structure_id_empty_new (struct1->name);
1658 for (i = 0; i < struct1->fields->len; i++) {
1659 GValue dest_value = { 0 };
1661 field1 = GST_STRUCTURE_FIELD (struct1, i);
1662 field2 = gst_structure_id_get_field (struct2, field1->name);
1664 if (field2 == NULL) {
1667 if (gst_value_union (&dest_value, &field1->value, &field2->value)) {
1668 gst_structure_set_value (dest, g_quark_to_string (field1->name),
1671 ret = gst_value_compare (&field1->value, &field2->value);
1682 * @caps1: a #GstCaps to union
1683 * @caps2: a #GstCaps to union
1685 * Creates a new #GstCaps that contains all the formats that are in
1686 * either @caps1 and @caps2.
1688 * Returns: the new #GstCaps
1691 gst_caps_union (const GstCaps * caps1, const GstCaps * caps2)
1696 /* NULL pointers are no correct GstCaps */
1697 g_return_val_if_fail (caps1 != NULL, NULL);
1698 g_return_val_if_fail (caps2 != NULL, NULL);
1700 if (CAPS_IS_EMPTY (caps1))
1701 return gst_caps_copy (caps2);
1703 if (CAPS_IS_EMPTY (caps2))
1704 return gst_caps_copy (caps1);
1706 if (CAPS_IS_ANY (caps1) || CAPS_IS_ANY (caps2))
1707 return gst_caps_new_any ();
1709 dest1 = gst_caps_copy (caps1);
1710 dest2 = gst_caps_copy (caps2);
1711 gst_caps_append (dest1, dest2);
1713 gst_caps_do_simplify (dest1);
1717 /* normalize/simplify operations */
1719 typedef struct _NormalizeForeach
1722 GstStructure *structure;
1727 gst_caps_normalize_foreach (GQuark field_id, const GValue * value, gpointer ptr)
1729 NormalizeForeach *nf = (NormalizeForeach *) ptr;
1733 if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
1734 guint len = gst_value_list_get_size (value);
1735 for (i = 1; i < len; i++) {
1736 const GValue *v = gst_value_list_get_value (value, i);
1737 GstStructure *structure = gst_structure_copy (nf->structure);
1739 gst_structure_id_set_value (structure, field_id, v);
1740 gst_caps_append_structure_unchecked (nf->caps, structure);
1743 gst_value_init_and_copy (&val, gst_value_list_get_value (value, 0));
1744 gst_structure_id_set_value (nf->structure, field_id, &val);
1745 g_value_unset (&val);
1753 * gst_caps_normalize:
1754 * @caps: a #GstCaps to normalize
1756 * Creates a new #GstCaps that represents the same set of formats as
1757 * @caps, but contains no lists. Each list is expanded into separate
1760 * Returns: the new #GstCaps
1763 gst_caps_normalize (const GstCaps * caps)
1765 NormalizeForeach nf;
1769 g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
1771 newcaps = gst_caps_copy (caps);
1774 for (i = 0; i < gst_caps_get_size (newcaps); i++) {
1775 nf.structure = gst_caps_get_structure_unchecked (newcaps, i);
1777 while (!gst_structure_foreach (nf.structure,
1778 gst_caps_normalize_foreach, &nf));
1785 gst_caps_compare_structures (gconstpointer one, gconstpointer two)
1788 const GstStructure *struct1 = *((const GstStructure **) one);
1789 const GstStructure *struct2 = *((const GstStructure **) two);
1791 /* FIXME: this orders alphabetically, but ordering the quarks might be faster
1792 So what's the best way? */
1793 ret = strcmp (gst_structure_get_name (struct1),
1794 gst_structure_get_name (struct2));
1798 return gst_structure_n_fields (struct2) - gst_structure_n_fields (struct1);
1805 GstStructure *compare;
1810 gst_caps_structure_figure_out_union (GQuark field_id, const GValue * value,
1813 UnionField *u = user_data;
1814 const GValue *val = gst_structure_id_get_value (u->compare, field_id);
1818 g_value_unset (&u->value);
1821 if (gst_value_compare (val, value) == GST_VALUE_EQUAL)
1824 g_value_unset (&u->value);
1828 gst_value_union (&u->value, val, value);
1833 gst_caps_structure_simplify (GstStructure ** result,
1834 const GstStructure * simplify, GstStructure * compare)
1837 UnionField field = { 0, {0,}, NULL };
1839 /* try to subtract to get a real subset */
1840 if (gst_caps_structure_subtract (&list, simplify, compare)) {
1841 if (list == NULL) { /* no result */
1844 } else if (list->next == NULL) { /* one result */
1845 *result = list->data;
1846 g_slist_free (list);
1848 } else { /* multiple results */
1849 g_slist_foreach (list, (GFunc) gst_structure_free, NULL);
1850 g_slist_free (list);
1855 /* try to union both structs */
1856 field.compare = compare;
1857 if (gst_structure_foreach ((GstStructure *) simplify,
1858 gst_caps_structure_figure_out_union, &field)) {
1859 gboolean ret = FALSE;
1861 /* now we know all of simplify's fields are the same in compare
1862 * but at most one field: field.name */
1863 if (G_IS_VALUE (&field.value)) {
1864 if (gst_structure_n_fields (simplify) == gst_structure_n_fields (compare)) {
1865 gst_structure_id_set_value (compare, field.name, &field.value);
1869 g_value_unset (&field.value);
1870 } else if (gst_structure_n_fields (simplify) <=
1871 gst_structure_n_fields (compare)) {
1872 /* compare is just more specific, will be optimized away later */
1873 /* FIXME: do this here? */
1874 GST_LOG ("found a case that will be optimized later.");
1876 gchar *one = gst_structure_to_string (simplify);
1877 gchar *two = gst_structure_to_string (compare);
1880 ("caps mismatch: structures %s and %s claim to be possible to unify, but aren't",
1892 gst_caps_switch_structures (GstCaps * caps, GstStructure * old,
1893 GstStructure * new, gint i)
1895 gst_structure_set_parent_refcount (old, NULL);
1896 gst_structure_free (old);
1897 gst_structure_set_parent_refcount (new, &caps->refcount);
1898 g_ptr_array_index (caps->structs, i) = new;
1902 * gst_caps_do_simplify:
1903 * @caps: a #GstCaps to simplify
1905 * Modifies the given @caps inplace into a representation that represents the
1906 * same set of formats, but in a simpler form. Component structures that are
1907 * identical are merged. Component structures that have values that can be
1908 * merged are also merged.
1910 * Returns: TRUE, if the caps could be simplified
1913 gst_caps_do_simplify (GstCaps * caps)
1915 GstStructure *simplify, *compare, *result = NULL;
1917 gboolean changed = FALSE;
1919 g_return_val_if_fail (caps != NULL, FALSE);
1920 g_return_val_if_fail (IS_WRITABLE (caps), FALSE);
1922 if (gst_caps_get_size (caps) < 2)
1925 g_ptr_array_sort (caps->structs, gst_caps_compare_structures);
1927 start = caps->structs->len - 1;
1928 for (i = caps->structs->len - 1; i >= 0; i--) {
1929 simplify = gst_caps_get_structure_unchecked (caps, i);
1930 if (gst_structure_get_name_id (simplify) !=
1931 gst_structure_get_name_id (gst_caps_get_structure_unchecked (caps,
1934 for (j = start; j >= 0; j--) {
1937 compare = gst_caps_get_structure_unchecked (caps, j);
1938 if (gst_structure_get_name_id (simplify) !=
1939 gst_structure_get_name_id (compare)) {
1942 if (gst_caps_structure_simplify (&result, simplify, compare)) {
1944 gst_caps_switch_structures (caps, simplify, result, i);
1947 gst_caps_remove_structure (caps, i);
1959 /* gst_caps_do_simplify (caps); */
1965 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
1967 * gst_caps_save_thyself:
1968 * @caps: a #GstCaps structure
1969 * @parent: a XML parent node
1971 * Serializes a #GstCaps to XML and adds it as a child node of @parent.
1973 * Returns: a XML node pointer
1976 gst_caps_save_thyself (const GstCaps * caps, xmlNodePtr parent)
1978 char *s = gst_caps_to_string (caps);
1980 xmlNewChild (parent, NULL, (xmlChar *) "caps", (xmlChar *) s);
1986 * gst_caps_load_thyself:
1987 * @parent: a XML node
1989 * Creates a #GstCaps from its XML serialization.
1991 * Returns: a new #GstCaps structure
1994 gst_caps_load_thyself (xmlNodePtr parent)
1996 if (strcmp ("caps", (char *) parent->name) == 0) {
1997 return gst_caps_from_string ((gchar *) xmlNodeGetContent (parent));
2008 * @caps: a pointer to #GstCaps
2009 * @newcaps: a #GstCaps to replace *caps
2011 * Replaces *caps with @newcaps. Unrefs the #GstCaps in the location
2012 * pointed to by @caps, if applicable, then modifies @caps to point to
2013 * @newcaps. An additional ref on @newcaps is taken.
2015 * This function does not take any locks so you might want to lock
2016 * the object owning @caps pointer.
2019 gst_caps_replace (GstCaps ** caps, GstCaps * newcaps)
2023 g_return_if_fail (caps != NULL);
2027 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p, %p -> %p", caps, oldcaps, newcaps);
2029 if (newcaps != oldcaps) {
2031 gst_caps_ref (newcaps);
2036 gst_caps_unref (oldcaps);
2041 * gst_caps_to_string:
2044 * Converts @caps to a string representation. This string representation
2045 * can be converted back to a #GstCaps by gst_caps_from_string().
2047 * For debugging purposes its easier to do something like this:
2049 * GST_LOG ("caps are %" GST_PTR_FORMAT, caps);
2051 * This prints the caps in human readble form.
2053 * Returns: a newly allocated string representing @caps.
2056 gst_caps_to_string (const GstCaps * caps)
2058 guint i, slen, clen;
2061 /* NOTE: This function is potentially called by the debug system,
2062 * so any calls to gst_log() (and GST_DEBUG(), GST_LOG(), etc.)
2063 * should be careful to avoid recursion. This includes any functions
2064 * called by gst_caps_to_string. In particular, calls should
2065 * not use the GST_PTR_FORMAT extension. */
2068 return g_strdup ("NULL");
2070 if (CAPS_IS_ANY (caps)) {
2071 return g_strdup ("ANY");
2073 if (CAPS_IS_EMPTY_SIMPLE (caps)) {
2074 return g_strdup ("EMPTY");
2077 /* estimate a rough string length to avoid unnecessary reallocs in GString */
2079 clen = caps->structs->len;
2080 for (i = 0; i < clen; i++) {
2082 STRUCTURE_ESTIMATED_STRING_LEN (gst_caps_get_structure_unchecked (caps,
2086 s = g_string_sized_new (slen);
2087 for (i = 0; i < clen; i++) {
2088 GstStructure *structure;
2091 /* ';' is now added by gst_structure_to_string */
2092 g_string_append_c (s, ' ');
2095 structure = gst_caps_get_structure_unchecked (caps, i);
2096 priv_gst_structure_append_to_gstring (structure, s);
2098 if (s->len && s->str[s->len - 1] == ';') {
2099 /* remove latest ';' */
2100 s->str[--s->len] = '\0';
2102 return g_string_free (s, FALSE);
2106 gst_caps_from_string_inplace (GstCaps * caps, const gchar * string)
2108 GstStructure *structure;
2111 if (strcmp ("ANY", string) == 0) {
2112 caps->flags = GST_CAPS_FLAGS_ANY;
2115 if (strcmp ("EMPTY", string) == 0) {
2119 structure = gst_structure_from_string (string, &s);
2120 if (structure == NULL) {
2123 gst_caps_append_structure_unchecked (caps, structure);
2127 while (g_ascii_isspace (*s))
2132 structure = gst_structure_from_string (s, &s);
2133 if (structure == NULL) {
2136 gst_caps_append_structure_unchecked (caps, structure);
2144 * gst_caps_from_string:
2145 * @string: a string to convert to #GstCaps
2147 * Converts @caps from a string representation.
2149 * Returns: a newly allocated #GstCaps
2152 gst_caps_from_string (const gchar * string)
2156 g_return_val_if_fail (string, FALSE);
2158 caps = gst_caps_new_empty ();
2159 if (gst_caps_from_string_inplace (caps, string)) {
2162 gst_caps_unref (caps);
2168 gst_caps_transform_to_string (const GValue * src_value, GValue * dest_value)
2170 g_return_if_fail (G_IS_VALUE (src_value));
2171 g_return_if_fail (G_IS_VALUE (dest_value));
2172 g_return_if_fail (G_VALUE_HOLDS (src_value, GST_TYPE_CAPS));
2173 g_return_if_fail (G_VALUE_HOLDS (dest_value, G_TYPE_STRING)
2174 || G_VALUE_HOLDS (dest_value, G_TYPE_POINTER));
2176 dest_value->data[0].v_pointer =
2177 gst_caps_to_string (src_value->data[0].v_pointer);
2181 gst_caps_copy_conditional (GstCaps * src)
2184 return gst_caps_ref (src);