2 * Copyright (C) 2013 Collabora Ltd.
3 * Author: Sebastian Dröge <sebastian.droege@collabora.co.uk>
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
15 * You should have received a copy of the GNU Library General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
18 * Boston, MA 02110-1301, USA.
22 * SECTION:gstcapsfeatures
23 * @short_description: A set of features in caps
26 * #GstCapsFeatures can optionally be set on a #GstCaps to add requirements
27 * for additional features for a specific #GstStructure. Caps structures with
28 * the same name but with a non-equal set of caps features are not compatible.
29 * If a pad supports multiple sets of features it has to add multiple equal
30 * structures with different feature sets to the caps.
32 * Empty #GstCapsFeatures are equivalent with the #GstCapsFeatures that only
33 * contain #GST_CAPS_FEATURE_MEMORY_SYSTEM_MEMORY.
35 * Examples for caps features would be the requirement of a specific #GstMemory
36 * types or the requirement of having a specific #GstMeta on the buffer. Features
37 * are given as a string of the format "memory:GstMemoryTypeName" or
38 * "meta:GstMetaAPIName".
46 #include "gst_private.h"
47 #include "gstcapsfeatures.h"
50 GST_DEBUG_CATEGORY_STATIC (gst_caps_features_debug);
51 #define GST_CAT_DEFAULT gst_caps_features_debug
53 struct _GstCapsFeatures
56 gint *parent_refcount;
61 GType _gst_caps_features_type = 0;
62 GstCapsFeatures *_gst_caps_features_any = NULL;
63 GstCapsFeatures *_gst_caps_features_memory_system_memory = NULL;
64 static GQuark _gst_caps_feature_memory_system_memory = 0;
66 G_DEFINE_BOXED_TYPE (GstCapsFeatures, gst_caps_features,
67 gst_caps_features_copy, gst_caps_features_free);
69 #define IS_MUTABLE(features) \
70 (!features->parent_refcount || \
71 g_atomic_int_get (features->parent_refcount) == 1)
74 gst_caps_features_transform_to_string (const GValue * src_value,
78 _priv_gst_caps_features_initialize (void)
80 _gst_caps_features_type = gst_caps_features_get_type ();
81 _gst_caps_feature_memory_system_memory =
82 g_quark_from_static_string (GST_CAPS_FEATURE_MEMORY_SYSTEM_MEMORY);
84 g_value_register_transform_func (_gst_caps_features_type, G_TYPE_STRING,
85 gst_caps_features_transform_to_string);
87 _gst_caps_features_any = gst_caps_features_new_any ();
88 _gst_caps_features_memory_system_memory =
89 gst_caps_features_new_id (_gst_caps_feature_memory_system_memory, 0);
91 GST_DEBUG_CATEGORY_INIT (gst_caps_features_debug, "caps-features", 0,
92 "GstCapsFeatures debug");
96 gst_is_caps_features (gconstpointer obj)
98 const GstCapsFeatures *features = obj;
100 return (obj != NULL && features->type == _gst_caps_features_type);
104 gst_caps_feature_name_is_valid (const gchar * feature)
106 #ifndef G_DISABLE_CHECKS
108 if (g_ascii_isalpha (*feature))
110 else if (*feature == ':')
120 if (*feature == '\0' || !g_ascii_isalpha (*feature))
124 if (g_ascii_isalnum (*feature))
126 else if (*feature == '\0')
137 * gst_caps_features_new_empty:
139 * Creates a new, empty #GstCapsFeatures.
141 * Free-function: gst_caps_features_free
143 * Returns: (transfer full): a new, empty #GstCapsFeatures
146 gst_caps_features_new_empty (void)
148 GstCapsFeatures *features;
150 features = g_slice_new (GstCapsFeatures);
151 features->type = _gst_caps_features_type;
152 features->parent_refcount = NULL;
153 features->array = g_array_new (FALSE, FALSE, sizeof (GQuark));
154 features->is_any = FALSE;
156 GST_TRACE ("created caps features %p", features);
162 * gst_caps_features_new_any:
164 * Creates a new, ANY #GstCapsFeatures. This will be equal
165 * to any other #GstCapsFeatures but caps with these are
168 * Free-function: gst_caps_features_free
170 * Returns: (transfer full): a new, ANY #GstCapsFeatures
173 gst_caps_features_new_any (void)
175 GstCapsFeatures *features;
177 features = gst_caps_features_new_empty ();
178 features->is_any = TRUE;
184 * gst_caps_features_new:
185 * @feature1: name of first feature to set
186 * @...: additional features
188 * Creates a new #GstCapsFeatures with the given features.
189 * The last argument must be NULL.
191 * Free-function: gst_caps_features_free
193 * Returns: (transfer full): a new, empty #GstCapsFeatures
196 gst_caps_features_new (const gchar * feature1, ...)
198 GstCapsFeatures *features;
201 g_return_val_if_fail (feature1 != NULL, NULL);
203 va_start (varargs, feature1);
204 features = gst_caps_features_new_valist (feature1, varargs);
211 * gst_caps_features_new_valist:
212 * @feature1: name of first feature to set
213 * @varargs: variable argument list
215 * Creates a new #GstCapsFeatures with the given features.
217 * Free-function: gst_caps_features_free
219 * Returns: (transfer full): a new, empty #GstCapsFeatures
222 gst_caps_features_new_valist (const gchar * feature1, va_list varargs)
224 GstCapsFeatures *features;
226 g_return_val_if_fail (feature1 != NULL, NULL);
228 features = gst_caps_features_new_empty ();
231 gst_caps_features_add (features, feature1);
232 feature1 = va_arg (varargs, const gchar *);
239 * gst_caps_features_new_id:
240 * @feature1: name of first feature to set
241 * @...: additional features
243 * Creates a new #GstCapsFeatures with the given features.
244 * The last argument must be 0.
246 * Free-function: gst_caps_features_free
248 * Returns: (transfer full): a new, empty #GstCapsFeatures
251 gst_caps_features_new_id (GQuark feature1, ...)
253 GstCapsFeatures *features;
256 g_return_val_if_fail (feature1 != 0, NULL);
258 va_start (varargs, feature1);
259 features = gst_caps_features_new_id_valist (feature1, varargs);
266 * gst_caps_features_new_id_valist:
267 * @feature1: name of first feature to set
268 * @varargs: variable argument list
270 * Creates a new #GstCapsFeatures with the given features.
272 * Free-function: gst_caps_features_free
274 * Returns: (transfer full): a new, empty #GstCapsFeatures
277 gst_caps_features_new_id_valist (GQuark feature1, va_list varargs)
279 GstCapsFeatures *features;
281 g_return_val_if_fail (feature1 != 0, NULL);
283 features = gst_caps_features_new_empty ();
286 gst_caps_features_add_id (features, feature1);
287 feature1 = va_arg (varargs, GQuark);
294 * gst_caps_features_set_parent_refcount:
295 * @features: a #GstCapsFeatures
296 * @refcount: (in): a pointer to the parent's refcount
298 * Sets the parent_refcount field of #GstCapsFeatures. This field is used to
299 * determine whether a caps features is mutable or not. This function should only be
300 * called by code implementing parent objects of #GstCapsFeatures, as described in
301 * the MT Refcounting section of the design documents.
303 * Returns: %TRUE if the parent refcount could be set.
306 gst_caps_features_set_parent_refcount (GstCapsFeatures * features,
309 g_return_val_if_fail (features != NULL, FALSE);
311 /* if we have a parent_refcount already, we can only clear
312 * if with a NULL refcount */
313 if (features->parent_refcount) {
314 if (refcount != NULL) {
315 g_return_val_if_fail (refcount == NULL, FALSE);
319 if (refcount == NULL) {
320 g_return_val_if_fail (refcount != NULL, FALSE);
325 features->parent_refcount = refcount;
331 * gst_caps_features_copy:
332 * @features: a #GstCapsFeatures to duplicate
334 * Duplicates a #GstCapsFeatures and all its values.
336 * Free-function: gst_caps_features_free
338 * Returns: (transfer full): a new #GstCapsFeatures.
341 gst_caps_features_copy (const GstCapsFeatures * features)
343 GstCapsFeatures *copy;
346 g_return_val_if_fail (features != NULL, NULL);
348 copy = gst_caps_features_new_empty ();
349 n = gst_caps_features_get_size (features);
350 for (i = 0; i < n; i++)
351 gst_caps_features_add_id (copy, gst_caps_features_get_nth_id (features, i));
357 * gst_caps_features_free:
358 * @features: (in) (transfer full): the #GstCapsFeatures to free
360 * Frees a #GstCapsFeatures and all its values. The caps features must not
361 * have a parent when this function is called.
364 gst_caps_features_free (GstCapsFeatures * features)
366 g_return_if_fail (features != NULL);
367 g_return_if_fail (features->parent_refcount == NULL);
369 g_array_free (features->array, TRUE);
371 memset (features, 0xff, sizeof (GstCapsFeatures));
373 GST_TRACE ("free caps features %p", features);
375 g_slice_free (GstCapsFeatures, features);
379 * gst_caps_features_to_string:
380 * @features: a #GstCapsFeatures
382 * Converts @features to a human-readable string representation.
384 * For debugging purposes its easier to do something like this:
386 * GST_LOG ("features is %" GST_PTR_FORMAT, features);
388 * This prints the features in human readble form.
390 * Free-function: g_free
392 * Returns: (transfer full): a pointer to string allocated by g_malloc().
393 * g_free() after usage.
396 gst_caps_features_to_string (const GstCapsFeatures * features)
400 g_return_val_if_fail (features != NULL, NULL);
402 s = g_string_sized_new (FEATURES_ESTIMATED_STRING_LEN (features));
404 priv_gst_caps_features_append_to_gstring (features, s);
406 return g_string_free (s, FALSE);
410 priv_gst_caps_features_append_to_gstring (const GstCapsFeatures * features,
415 g_return_if_fail (features != NULL);
417 if (features->array->len == 0 && features->is_any) {
418 g_string_append (s, "ANY");
422 n = features->array->len;
423 for (i = 0; i < n; i++) {
424 GQuark *quark = &g_array_index (features->array, GQuark, i);
426 g_string_append (s, g_quark_to_string (*quark));
428 g_string_append (s, ", ");
433 * gst_caps_features_from_string:
434 * @features: a string representation of a #GstCapsFeatures.
436 * Creates a #GstCapsFeatures from a string representation.
438 * Free-function: gst_caps_features_free
440 * Returns: (transfer full): a new #GstCapsFeatures or NULL when the string could
441 * not be parsed. Free with gst_caps_features_free() after use.
444 gst_caps_features_from_string (const gchar * features)
446 GstCapsFeatures *ret;
447 gboolean escape = FALSE;
448 const gchar *features_orig = features;
449 const gchar *feature;
451 ret = gst_caps_features_new_empty ();
453 if (!features || *features == '\0')
456 if (strcmp (features, "ANY") == 0) {
461 /* Skip trailing spaces */
462 while (*features == ' ')
473 } else if ((!escape && c == ',') || c == '\0') {
474 guint len = features - feature + 1;
479 g_warning ("Failed deserialize caps features '%s'", features_orig);
480 gst_caps_features_free (ret);
484 tmp = g_malloc (len);
485 memcpy (tmp, feature, len - 1);
494 if (strstr (tmp, " ") != NULL || *tmp == '\0') {
496 g_warning ("Failed deserialize caps features '%s'", features_orig);
497 gst_caps_features_free (ret);
501 gst_caps_features_add (ret, tmp);
507 /* Skip to the next value */
509 while (*features == ' ')
522 * gst_caps_features_get_size:
523 * @features: a #GstCapsFeatures.
525 * Returns the number of features in @features.
527 * Returns: The number of features in @features.
530 gst_caps_features_get_size (const GstCapsFeatures * features)
532 g_return_val_if_fail (features != NULL, 0);
534 return features->array->len;
538 * gst_caps_features_get_nth:
539 * @features: a #GstCapsFeatures.
540 * @i: index of the feature
542 * Returns the @i-th feature of @features.
544 * Returns: The @i-th feature of @features.
547 gst_caps_features_get_nth (const GstCapsFeatures * features, guint i)
549 const gchar *feature;
552 g_return_val_if_fail (features != NULL, NULL);
554 quark = gst_caps_features_get_nth_id (features, i);
558 feature = g_quark_to_string (quark);
563 * gst_caps_features_get_nth_id:
564 * @features: a #GstCapsFeatures.
565 * @i: index of the feature
567 * Returns the @i-th feature of @features.
569 * Returns: The @i-th feature of @features.
572 gst_caps_features_get_nth_id (const GstCapsFeatures * features, guint i)
576 g_return_val_if_fail (features != NULL, 0);
577 g_return_val_if_fail (i < features->array->len, 0);
579 quark = &g_array_index (features->array, GQuark, i);
585 * gst_caps_features_contains:
586 * @features: a #GstCapsFeatures.
587 * @feature: a feature
589 * Returns %TRUE if @features contains @feature.
591 * Returns: %TRUE if @features contains @feature.
594 gst_caps_features_contains (const GstCapsFeatures * features,
595 const gchar * feature)
597 g_return_val_if_fail (features != NULL, FALSE);
598 g_return_val_if_fail (feature != NULL, FALSE);
600 return gst_caps_features_contains_id (features,
601 g_quark_from_string (feature));
605 * gst_caps_features_contains_id:
606 * @features: a #GstCapsFeatures.
607 * @feature: a feature
609 * Returns %TRUE if @features contains @feature.
611 * Returns: %TRUE if @features contains @feature.
614 gst_caps_features_contains_id (const GstCapsFeatures * features, GQuark feature)
618 g_return_val_if_fail (features != NULL, FALSE);
619 g_return_val_if_fail (feature != 0, FALSE);
621 if (features->is_any)
624 n = features->array->len;
626 return feature == _gst_caps_feature_memory_system_memory;
628 for (i = 0; i < n; i++) {
629 if (gst_caps_features_get_nth_id (features, i) == feature)
637 * gst_caps_features_is_equal:
638 * @features1: a #GstCapsFeatures.
639 * @features2: a #GstCapsFeatures.
641 * Returns %TRUE if @features1 and @features2 are equal.
643 * Returns: %TRUE if @features1 and @features2 are equal.
646 gst_caps_features_is_equal (const GstCapsFeatures * features1,
647 const GstCapsFeatures * features2)
651 g_return_val_if_fail (features1 != NULL, FALSE);
652 g_return_val_if_fail (features2 != NULL, FALSE);
654 if (features1->is_any || features2->is_any)
657 /* Check for the sysmem==empty case */
658 if (features1->array->len == 0 && features2->array->len == 0)
660 if (features1->array->len == 0 && features2->array->len == 1
661 && gst_caps_features_contains_id (features2,
662 _gst_caps_feature_memory_system_memory))
664 if (features2->array->len == 0 && features1->array->len == 1
665 && gst_caps_features_contains_id (features1,
666 _gst_caps_feature_memory_system_memory))
669 if (features1->array->len != features2->array->len)
672 n = features1->array->len;
673 for (i = 0; i < n; i++)
674 if (!gst_caps_features_contains_id (features2,
675 gst_caps_features_get_nth_id (features1, i)))
682 * gst_caps_features_is_any:
683 * @features: a #GstCapsFeatures.
685 * Returns %TRUE if @features is %GST_CAPS_FEATURES_ANY.
687 * Returns: %TRUE if @features is %GST_CAPS_FEATURES_ANY.
690 gst_caps_features_is_any (const GstCapsFeatures * features)
692 g_return_val_if_fail (features != NULL, FALSE);
694 return features->is_any;
698 * gst_caps_features_add:
699 * @features: a #GstCapsFeatures.
700 * @feature: a feature.
702 * Adds @feature to @features.
705 gst_caps_features_add (GstCapsFeatures * features, const gchar * feature)
707 g_return_if_fail (features != NULL);
708 g_return_if_fail (IS_MUTABLE (features));
709 g_return_if_fail (feature != NULL);
710 g_return_if_fail (!features->is_any);
712 gst_caps_features_add_id (features, g_quark_from_string (feature));
716 * gst_caps_features_add_id:
717 * @features: a #GstCapsFeatures.
718 * @feature: a feature.
720 * Adds @feature to @features.
723 gst_caps_features_add_id (GstCapsFeatures * features, GQuark feature)
725 g_return_if_fail (features != NULL);
726 g_return_if_fail (IS_MUTABLE (features));
727 g_return_if_fail (feature != 0);
728 g_return_if_fail (!features->is_any);
730 if (!gst_caps_feature_name_is_valid (g_quark_to_string (feature))) {
731 g_warning ("Invalid caps feature name: %s", g_quark_to_string (feature));
735 /* If features is empty it will contain sysmem, however
736 * we want to add it explicitely if it is tried to be
737 * added as first features
739 if (features->array->len > 0
740 && gst_caps_features_contains_id (features, feature))
743 g_array_append_val (features->array, feature);
747 * gst_caps_features_remove:
748 * @features: a #GstCapsFeatures.
749 * @feature: a feature.
751 * Removes @feature from @features.
754 gst_caps_features_remove (GstCapsFeatures * features, const gchar * feature)
756 g_return_if_fail (features != NULL);
757 g_return_if_fail (IS_MUTABLE (features));
758 g_return_if_fail (feature != NULL);
760 gst_caps_features_remove_id (features, g_quark_from_string (feature));
764 * gst_caps_features_remove_id:
765 * @features: a #GstCapsFeatures.
766 * @feature: a feature.
768 * Removes @feature from @features.
771 gst_caps_features_remove_id (GstCapsFeatures * features, GQuark feature)
775 g_return_if_fail (features != NULL);
776 g_return_if_fail (IS_MUTABLE (features));
777 g_return_if_fail (feature != 0);
779 n = features->array->len;
780 for (i = 0; i < n; i++) {
781 GQuark quark = gst_caps_features_get_nth_id (features, i);
783 if (quark == feature) {
784 g_array_remove_index_fast (features->array, i);
791 gst_caps_features_transform_to_string (const GValue * src_value,
794 g_return_if_fail (src_value != NULL);
795 g_return_if_fail (dest_value != NULL);
797 dest_value->data[0].v_pointer =
798 gst_caps_features_to_string (src_value->data[0].v_pointer);