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., 51 Franklin St, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
20 #ifndef __GST_CAPS_H__
21 #define __GST_CAPS_H__
23 #include <gst/gstconfig.h>
24 #include <gst/gstminiobject.h>
25 #include <gst/gststructure.h>
26 #include <gst/gstcapsfeatures.h>
27 #include <gst/glib-compat.h>
31 GST_API GType _gst_caps_type;
33 #define GST_TYPE_CAPS (_gst_caps_type)
34 #define GST_IS_CAPS(obj) (GST_IS_MINI_OBJECT_TYPE((obj), GST_TYPE_CAPS))
35 #define GST_CAPS_CAST(obj) ((GstCaps*)(obj))
36 #define GST_CAPS(obj) (GST_CAPS_CAST(obj))
38 #define GST_TYPE_STATIC_CAPS (gst_static_caps_get_type())
42 * @GST_CAPS_FLAG_ANY: Caps has no specific content, but can contain
45 * Extra flags for a caps.
48 GST_CAPS_FLAG_ANY = (GST_MINI_OBJECT_FLAG_LAST << 0)
52 * GstCapsIntersectMode:
53 * @GST_CAPS_INTERSECT_ZIG_ZAG : Zig-zags over both caps.
54 * @GST_CAPS_INTERSECT_FIRST : Keeps the first caps order.
56 * Modes of caps intersection
58 * @GST_CAPS_INTERSECT_ZIG_ZAG tries to preserve overall order of both caps
59 * by iterating on the caps' structures as the following matrix shows:
67 * Used when there is no explicit precedence of one caps over the other. e.g.
68 * tee's sink pad getcaps function, it will probe its src pad peers' for their
69 * caps and intersect them with this mode.
71 * @GST_CAPS_INTERSECT_FIRST is useful when an element wants to preserve
72 * another element's caps priority order when intersecting with its own caps.
73 * Example: If caps1 is [A, B, C] and caps2 is [E, B, D, A], the result
74 * would be [A, B], maintaining the first caps priority on the intersection.
77 GST_CAPS_INTERSECT_ZIG_ZAG = 0,
78 GST_CAPS_INTERSECT_FIRST = 1
79 } GstCapsIntersectMode;
84 * Means that the element/pad can output 'anything'. Useful for elements
85 * that output unknown media, such as filesrc. This macro returns a singleton and
86 * should not be unreffed.
88 #define GST_CAPS_ANY _gst_caps_any
92 * The opposite of %GST_CAPS_ANY: it means that the pad/element outputs an
93 * undefined media type that can not be detected. This macro returns a singleton
94 * and should not be unreffed.
96 #define GST_CAPS_NONE _gst_caps_none
99 * GST_STATIC_CAPS_ANY:
101 * Creates a new #GstCaps static caps that matches anything.
102 * This can be used in pad templates.
104 #define GST_STATIC_CAPS_ANY GST_STATIC_CAPS("ANY")
106 * GST_STATIC_CAPS_NONE:
108 * Creates a new #GstCaps static caps that matches nothing.
109 * This can be used in pad templates.
111 #define GST_STATIC_CAPS_NONE GST_STATIC_CAPS("NONE")
114 * GST_CAPS_IS_SIMPLE:
115 * @caps: the #GstCaps instance to check
117 * Convenience macro that checks if the number of structures in the given caps
120 #define GST_CAPS_IS_SIMPLE(caps) (gst_caps_get_size(caps) == 1)
124 * @string: the string describing the caps
126 * Creates a new #GstCaps static caps from an input string.
127 * This can be used in pad templates.
129 #define GST_STATIC_CAPS(string) \
132 /* string */ string, \
136 typedef struct _GstCaps GstCaps;
137 typedef struct _GstStaticCaps GstStaticCaps;
139 GST_API GstCaps * _gst_caps_any;
141 GST_API GstCaps * _gst_caps_none;
146 * A flags word containing #GstCapsFlags flags set on this caps.
148 #define GST_CAPS_FLAGS(caps) GST_MINI_OBJECT_FLAGS(caps)
155 * Get access to the reference count field of the caps
157 #define GST_CAPS_REFCOUNT(caps) GST_MINI_OBJECT_REFCOUNT(caps)
159 * GST_CAPS_REFCOUNT_VALUE:
162 * Get the reference count value of the caps.
164 #define GST_CAPS_REFCOUNT_VALUE(caps) GST_MINI_OBJECT_REFCOUNT_VALUE(caps)
167 * GST_CAPS_FLAG_IS_SET:
169 * @flag: the #GstCapsFlags to check.
171 * Gives the status of a specific flag on a caps.
173 #define GST_CAPS_FLAG_IS_SET(caps,flag) GST_MINI_OBJECT_FLAG_IS_SET (caps, flag)
177 * @flag: the #GstCapsFlags to set.
179 * Sets a caps flag on a caps.
181 #define GST_CAPS_FLAG_SET(caps,flag) GST_MINI_OBJECT_FLAG_SET (caps, flag)
183 * GST_CAPS_FLAG_UNSET:
185 * @flag: the #GstCapsFlags to clear.
187 * Clears a caps flag.
189 #define GST_CAPS_FLAG_UNSET(caps,flag) GST_MINI_OBJECT_FLAG_UNSET (caps, flag)
193 * gst_caps_ref: (skip)
194 * @caps: the #GstCaps to reference
196 * Add a reference to a #GstCaps object.
198 * From this point on, until the caller calls gst_caps_unref() or
199 * gst_caps_make_writable(), it is guaranteed that the caps object will not
200 * change. This means its structures won't change, etc. To use a #GstCaps
201 * object, you must always have a refcount on it -- either the one made
202 * implicitly by e.g. gst_caps_new_simple(), or via taking one explicitly with
205 * Returns: the same #GstCaps object.
207 static inline GstCaps * gst_caps_ref (GstCaps * caps);
208 static inline GstCaps *
209 gst_caps_ref (GstCaps * caps)
211 return (GstCaps *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (caps));
215 * gst_caps_unref: (skip)
218 * Unref a #GstCaps and and free all its structures and the
219 * structures' values when the refcount reaches 0.
221 static inline void gst_caps_unref (GstCaps * caps);
223 gst_caps_unref (GstCaps * caps)
225 gst_mini_object_unref (GST_MINI_OBJECT_CAST (caps));
229 * gst_clear_caps: (skip)
230 * @caps_ptr: a pointer to a #GstCaps reference
232 * Clears a reference to a #GstCaps.
234 * @caps_ptr must not be %NULL.
236 * If the reference is %NULL then this function does nothing. Otherwise, the
237 * reference count of the caps is decreased and the pointer is set to %NULL.
242 gst_clear_caps (GstCaps ** caps_ptr)
244 gst_clear_mini_object ((GstMiniObject **) caps_ptr);
249 GstCaps * gst_caps_copy (const GstCaps * caps);
251 #define gst_caps_copy(caps) GST_CAPS (gst_mini_object_copy (GST_MINI_OBJECT_CAST (caps)))
254 * gst_caps_is_writable:
257 * Tests if you can safely modify @caps. It is only safe to modify caps when
258 * there is only one owner of the caps - ie, the object is writable.
260 #define gst_caps_is_writable(caps) gst_mini_object_is_writable (GST_MINI_OBJECT_CAST (caps))
263 * gst_caps_make_writable:
264 * @caps: (transfer full): a #GstCaps
266 * Returns a writable copy of @caps.
268 * If there is only one reference count on @caps, the caller must be the owner,
269 * and so this function will return the caps object unchanged. If on the other
270 * hand there is more than one reference on the object, a new caps object will
271 * be returned. The caller's reference on @caps will be removed, and instead the
272 * caller will own a reference to the returned object.
274 * In short, this function unrefs the caps in the argument and refs the caps
275 * that it returns. Don't access the argument after calling this function. See
276 * also: gst_caps_ref().
278 * Returns: (transfer full): a writable caps which may or may not be the
281 #define gst_caps_make_writable(caps) GST_CAPS_CAST (gst_mini_object_make_writable (GST_MINI_OBJECT_CAST (caps)))
284 * gst_caps_replace: (skip)
285 * @old_caps: (inout) (transfer full) (nullable): pointer to a pointer
286 * to a #GstCaps to be replaced.
287 * @new_caps: (transfer none) (allow-none): pointer to a #GstCaps that will
288 * replace the caps pointed to by @old_caps.
290 * Modifies a pointer to a #GstCaps to point to a different #GstCaps. The
291 * modification is done atomically (so this is useful for ensuring thread safety
292 * in some cases), and the reference counts are updated appropriately (the old
293 * caps is unreffed, the new is reffed).
295 * Either @new_caps or the #GstCaps pointed to by @old_caps may be %NULL.
297 * Returns: %TRUE if @new_caps was different from @old_caps
299 static inline gboolean gst_caps_replace (GstCaps **old_caps, GstCaps *new_caps);
300 static inline gboolean
301 gst_caps_replace (GstCaps **old_caps, GstCaps *new_caps)
303 return gst_mini_object_replace ((GstMiniObject **) old_caps, (GstMiniObject *) new_caps);
307 * gst_caps_take: (skip)
308 * @old_caps: (inout) (transfer full): pointer to a pointer to a #GstCaps to be
310 * @new_caps: (transfer full) (allow-none): pointer to a #GstCaps that will
311 * replace the caps pointed to by @old_caps.
313 * Modifies a pointer to a #GstCaps to point to a different #GstCaps. This
314 * function is similar to gst_caps_replace() except that it takes ownership
317 * Returns: %TRUE if @new_caps was different from @old_caps
319 static inline gboolean gst_caps_take (GstCaps **old_caps, GstCaps *new_caps);
320 static inline gboolean
321 gst_caps_take (GstCaps **old_caps, GstCaps *new_caps)
323 return gst_mini_object_take ((GstMiniObject **) old_caps, (GstMiniObject *) new_caps);
328 * @mini_object: the parent type
330 * Object describing media types.
333 GstMiniObject mini_object;
338 * @caps: the cached #GstCaps
339 * @string: a string describing a caps
341 * Datastructure to initialize #GstCaps from a string description usually
342 * used in conjunction with GST_STATIC_CAPS() and gst_static_caps_get() to
343 * instantiate a #GstCaps.
345 struct _GstStaticCaps {
351 gpointer _gst_reserved[GST_PADDING];
355 * GstCapsForeachFunc:
356 * @features: the #GstCapsFeatures
357 * @structure: the #GstStructure
358 * @user_data: user data
360 * A function that will be called in gst_caps_foreach(). The function may
361 * not modify @features or @structure.
363 * Returns: %TRUE if the foreach operation should continue, %FALSE if
364 * the foreach operation should stop with %FALSE.
368 typedef gboolean (*GstCapsForeachFunc) (GstCapsFeatures *features,
369 GstStructure *structure,
374 * @features: the #GstCapsFeatures
375 * @structure: the #GstStructure
376 * @user_data: user data
378 * A function that will be called in gst_caps_map_in_place(). The function
379 * may modify @features and @structure.
381 * Returns: %TRUE if the map operation should continue, %FALSE if
382 * the map operation should stop with %FALSE.
384 typedef gboolean (*GstCapsMapFunc) (GstCapsFeatures *features,
385 GstStructure *structure,
389 * GstCapsFilterMapFunc:
390 * @features: the #GstCapsFeatures
391 * @structure: the #GstStructure
392 * @user_data: user data
394 * A function that will be called in gst_caps_filter_and_map_in_place().
395 * The function may modify @features and @structure, and both will be
396 * removed from the caps if %FALSE is returned.
398 * Returns: %TRUE if the features and structure should be preserved,
399 * %FALSE if it should be removed.
401 typedef gboolean (*GstCapsFilterMapFunc) (GstCapsFeatures *features,
402 GstStructure *structure,
407 GType gst_caps_get_type (void);
410 GstCaps * gst_caps_new_empty (void);
413 GstCaps * gst_caps_new_any (void);
416 GstCaps * gst_caps_new_empty_simple (const char *media_type) G_GNUC_WARN_UNUSED_RESULT;
419 GstCaps * gst_caps_new_simple (const char *media_type,
420 const char *fieldname,
421 ...) G_GNUC_NULL_TERMINATED G_GNUC_WARN_UNUSED_RESULT;
423 GstCaps * gst_caps_new_full (GstStructure *struct1,
424 ...) G_GNUC_NULL_TERMINATED G_GNUC_WARN_UNUSED_RESULT;
426 GstCaps * gst_caps_new_full_valist (GstStructure *structure,
427 va_list var_args) G_GNUC_WARN_UNUSED_RESULT;
429 * gst_static_caps_get_type: (attributes doc.skip=true)
432 GType gst_static_caps_get_type (void);
435 GstCaps * gst_static_caps_get (GstStaticCaps *static_caps);
438 void gst_static_caps_cleanup (GstStaticCaps *static_caps);
443 void gst_caps_append (GstCaps *caps1,
446 void gst_caps_append_structure (GstCaps *caps,
447 GstStructure *structure);
449 void gst_caps_append_structure_full (GstCaps *caps,
450 GstStructure *structure,
451 GstCapsFeatures *features);
453 void gst_caps_remove_structure (GstCaps *caps, guint idx);
456 GstCaps * gst_caps_merge (GstCaps *caps1,
457 GstCaps *caps2) G_GNUC_WARN_UNUSED_RESULT;
459 GstCaps * gst_caps_merge_structure (GstCaps *caps,
460 GstStructure *structure) G_GNUC_WARN_UNUSED_RESULT;
462 GstCaps * gst_caps_merge_structure_full (GstCaps *caps,
463 GstStructure *structure,
464 GstCapsFeatures *features) G_GNUC_WARN_UNUSED_RESULT;
467 guint gst_caps_get_size (const GstCaps *caps);
470 GstStructure * gst_caps_get_structure (const GstCaps *caps,
473 GstStructure * gst_caps_steal_structure (GstCaps *caps,
474 guint index) G_GNUC_WARN_UNUSED_RESULT;
476 void gst_caps_set_features (GstCaps *caps,
478 GstCapsFeatures * features);
480 void gst_caps_set_features_simple (GstCaps *caps,
481 GstCapsFeatures * features);
484 GstCapsFeatures * gst_caps_get_features (const GstCaps *caps,
487 GstCaps * gst_caps_copy_nth (const GstCaps *caps, guint nth) G_GNUC_WARN_UNUSED_RESULT;
490 GstCaps * gst_caps_truncate (GstCaps *caps) G_GNUC_WARN_UNUSED_RESULT;
493 void gst_caps_set_value (GstCaps *caps,
495 const GValue *value);
497 void gst_caps_set_simple (GstCaps *caps,
498 const char *field, ...) G_GNUC_NULL_TERMINATED;
500 void gst_caps_set_simple_valist (GstCaps *caps,
504 gboolean gst_caps_foreach (const GstCaps *caps,
505 GstCapsForeachFunc func,
508 gboolean gst_caps_map_in_place (GstCaps *caps,
512 void gst_caps_filter_and_map_in_place (GstCaps *caps,
513 GstCapsFilterMapFunc func,
519 gboolean gst_caps_is_any (const GstCaps *caps);
522 gboolean gst_caps_is_empty (const GstCaps *caps);
525 gboolean gst_caps_is_fixed (const GstCaps *caps);
528 gboolean gst_caps_is_always_compatible (const GstCaps *caps1,
529 const GstCaps *caps2);
531 gboolean gst_caps_is_subset (const GstCaps *subset,
532 const GstCaps *superset);
534 gboolean gst_caps_is_subset_structure (const GstCaps *caps,
535 const GstStructure *structure);
537 gboolean gst_caps_is_subset_structure_full (const GstCaps *caps,
538 const GstStructure *structure,
539 const GstCapsFeatures *features);
541 gboolean gst_caps_is_equal (const GstCaps *caps1,
542 const GstCaps *caps2);
544 gboolean gst_caps_is_equal_fixed (const GstCaps *caps1,
545 const GstCaps *caps2);
547 gboolean gst_caps_can_intersect (const GstCaps * caps1,
548 const GstCaps * caps2);
550 gboolean gst_caps_is_strictly_equal (const GstCaps *caps1,
551 const GstCaps *caps2);
557 GstCaps * gst_caps_intersect (GstCaps *caps1,
558 GstCaps *caps2) G_GNUC_WARN_UNUSED_RESULT;
560 GstCaps * gst_caps_intersect_full (GstCaps *caps1,
562 GstCapsIntersectMode mode) G_GNUC_WARN_UNUSED_RESULT;
564 GstCaps * gst_caps_subtract (GstCaps *minuend,
565 GstCaps *subtrahend) G_GNUC_WARN_UNUSED_RESULT;
567 GstCaps * gst_caps_normalize (GstCaps *caps) G_GNUC_WARN_UNUSED_RESULT;
570 GstCaps * gst_caps_simplify (GstCaps *caps) G_GNUC_WARN_UNUSED_RESULT;
573 GstCaps * gst_caps_fixate (GstCaps *caps) G_GNUC_WARN_UNUSED_RESULT;
578 gchar * gst_caps_to_string (const GstCaps *caps) G_GNUC_MALLOC;
581 GstCaps * gst_caps_from_string (const gchar *string) G_GNUC_WARN_UNUSED_RESULT;
583 #ifdef G_DEFINE_AUTOPTR_CLEANUP_FUNC
584 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstCaps, gst_caps_unref)
589 #endif /* __GST_CAPS_H__ */