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. ANY #GstCapsFeatures as
34 * created by gst_caps_features_new_any() are equal to any other #GstCapsFeatures
35 * and can be used to specify that any #GstCapsFeatures would be supported, e.g.
36 * for elements that don't touch buffer memory. #GstCaps with ANY #GstCapsFeatures
37 * are considered non-fixed and during negotiation some #GstCapsFeatures have
40 * Examples for caps features would be the requirement of a specific #GstMemory
41 * types or the requirement of having a specific #GstMeta on the buffer. Features
42 * are given as a string of the format "memory:GstMemoryTypeName" or
43 * "meta:GstMetaAPIName".
53 #include "gst_private.h"
54 #include "gstcapsfeatures.h"
57 GST_DEBUG_CATEGORY_STATIC (gst_caps_features_debug);
58 #define GST_CAT_DEFAULT gst_caps_features_debug
60 struct _GstCapsFeatures
63 gint *parent_refcount;
68 GType _gst_caps_features_type = 0;
69 GstCapsFeatures *_gst_caps_features_any = NULL;
70 GstCapsFeatures *_gst_caps_features_memory_system_memory = NULL;
71 static GQuark _gst_caps_feature_memory_system_memory = 0;
73 G_DEFINE_BOXED_TYPE (GstCapsFeatures, gst_caps_features,
74 gst_caps_features_copy, gst_caps_features_free);
76 #define IS_MUTABLE(features) \
77 (!features->parent_refcount || \
78 g_atomic_int_get (features->parent_refcount) == 1)
81 gst_caps_features_transform_to_string (const GValue * src_value,
85 _priv_gst_caps_features_initialize (void)
87 GST_DEBUG_CATEGORY_INIT (gst_caps_features_debug, "caps-features", 0,
88 "GstCapsFeatures debug");
90 _gst_caps_features_type = gst_caps_features_get_type ();
91 _gst_caps_feature_memory_system_memory =
92 g_quark_from_static_string (GST_CAPS_FEATURE_MEMORY_SYSTEM_MEMORY);
94 g_value_register_transform_func (_gst_caps_features_type, G_TYPE_STRING,
95 gst_caps_features_transform_to_string);
97 _gst_caps_features_any = gst_caps_features_new_any ();
98 _gst_caps_features_memory_system_memory =
99 gst_caps_features_new_id (_gst_caps_feature_memory_system_memory, 0);
103 gst_is_caps_features (gconstpointer obj)
105 const GstCapsFeatures *features = obj;
107 return (obj != NULL && features->type == _gst_caps_features_type);
111 gst_caps_feature_name_is_valid (const gchar * feature)
113 #ifndef G_DISABLE_CHECKS
115 if (g_ascii_isalpha (*feature))
117 else if (*feature == ':')
127 if (*feature == '\0' || !g_ascii_isalpha (*feature))
131 if (g_ascii_isalnum (*feature))
133 else if (*feature == '\0')
144 * gst_caps_features_new_empty:
146 * Creates a new, empty #GstCapsFeatures.
148 * Free-function: gst_caps_features_free
150 * Returns: (transfer full): a new, empty #GstCapsFeatures
155 gst_caps_features_new_empty (void)
157 GstCapsFeatures *features;
159 features = g_slice_new (GstCapsFeatures);
160 features->type = _gst_caps_features_type;
161 features->parent_refcount = NULL;
162 features->array = g_array_new (FALSE, FALSE, sizeof (GQuark));
163 features->is_any = FALSE;
165 GST_TRACE ("created caps features %p", features);
171 * gst_caps_features_new_any:
173 * Creates a new, ANY #GstCapsFeatures. This will be equal
174 * to any other #GstCapsFeatures but caps with these are
177 * Free-function: gst_caps_features_free
179 * Returns: (transfer full): a new, ANY #GstCapsFeatures
184 gst_caps_features_new_any (void)
186 GstCapsFeatures *features;
188 features = gst_caps_features_new_empty ();
189 features->is_any = TRUE;
195 * gst_caps_features_new:
196 * @feature1: name of first feature to set
197 * @...: additional features
199 * Creates a new #GstCapsFeatures with the given features.
200 * The last argument must be NULL.
202 * Free-function: gst_caps_features_free
204 * Returns: (transfer full): a new, empty #GstCapsFeatures
209 gst_caps_features_new (const gchar * feature1, ...)
211 GstCapsFeatures *features;
214 g_return_val_if_fail (feature1 != NULL, NULL);
216 va_start (varargs, feature1);
217 features = gst_caps_features_new_valist (feature1, varargs);
224 * gst_caps_features_new_valist:
225 * @feature1: name of first feature to set
226 * @varargs: variable argument list
228 * Creates a new #GstCapsFeatures with the given features.
230 * Free-function: gst_caps_features_free
232 * Returns: (transfer full): a new, empty #GstCapsFeatures
237 gst_caps_features_new_valist (const gchar * feature1, va_list varargs)
239 GstCapsFeatures *features;
241 g_return_val_if_fail (feature1 != NULL, NULL);
243 features = gst_caps_features_new_empty ();
246 gst_caps_features_add (features, feature1);
247 feature1 = va_arg (varargs, const gchar *);
254 * gst_caps_features_new_id:
255 * @feature1: name of first feature to set
256 * @...: additional features
258 * Creates a new #GstCapsFeatures with the given features.
259 * The last argument must be 0.
261 * Free-function: gst_caps_features_free
263 * Returns: (transfer full): a new, empty #GstCapsFeatures
268 gst_caps_features_new_id (GQuark feature1, ...)
270 GstCapsFeatures *features;
273 g_return_val_if_fail (feature1 != 0, NULL);
275 va_start (varargs, feature1);
276 features = gst_caps_features_new_id_valist (feature1, varargs);
283 * gst_caps_features_new_id_valist:
284 * @feature1: name of first feature to set
285 * @varargs: variable argument list
287 * Creates a new #GstCapsFeatures with the given features.
289 * Free-function: gst_caps_features_free
291 * Returns: (transfer full): a new, empty #GstCapsFeatures
296 gst_caps_features_new_id_valist (GQuark feature1, va_list varargs)
298 GstCapsFeatures *features;
300 g_return_val_if_fail (feature1 != 0, NULL);
302 features = gst_caps_features_new_empty ();
305 gst_caps_features_add_id (features, feature1);
306 feature1 = va_arg (varargs, GQuark);
313 * gst_caps_features_set_parent_refcount:
314 * @features: a #GstCapsFeatures
315 * @refcount: (in): a pointer to the parent's refcount
317 * Sets the parent_refcount field of #GstCapsFeatures. This field is used to
318 * determine whether a caps features is mutable or not. This function should only be
319 * called by code implementing parent objects of #GstCapsFeatures, as described in
320 * the MT Refcounting section of the design documents.
322 * Returns: %TRUE if the parent refcount could be set.
327 gst_caps_features_set_parent_refcount (GstCapsFeatures * features,
330 g_return_val_if_fail (features != NULL, FALSE);
332 /* if we have a parent_refcount already, we can only clear
333 * if with a NULL refcount */
334 if (features->parent_refcount) {
335 if (refcount != NULL) {
336 g_return_val_if_fail (refcount == NULL, FALSE);
340 if (refcount == NULL) {
341 g_return_val_if_fail (refcount != NULL, FALSE);
346 features->parent_refcount = refcount;
352 * gst_caps_features_copy:
353 * @features: a #GstCapsFeatures to duplicate
355 * Duplicates a #GstCapsFeatures and all its values.
357 * Free-function: gst_caps_features_free
359 * Returns: (transfer full): a new #GstCapsFeatures.
364 gst_caps_features_copy (const GstCapsFeatures * features)
366 GstCapsFeatures *copy;
369 g_return_val_if_fail (features != NULL, NULL);
371 copy = gst_caps_features_new_empty ();
372 n = gst_caps_features_get_size (features);
373 for (i = 0; i < n; i++)
374 gst_caps_features_add_id (copy, gst_caps_features_get_nth_id (features, i));
375 copy->is_any = features->is_any;
381 * gst_caps_features_free:
382 * @features: (in) (transfer full): the #GstCapsFeatures to free
384 * Frees a #GstCapsFeatures and all its values. The caps features must not
385 * have a parent when this function is called.
390 gst_caps_features_free (GstCapsFeatures * features)
392 g_return_if_fail (features != NULL);
393 g_return_if_fail (features->parent_refcount == NULL);
395 g_array_free (features->array, TRUE);
397 memset (features, 0xff, sizeof (GstCapsFeatures));
399 GST_TRACE ("free caps features %p", features);
401 g_slice_free (GstCapsFeatures, features);
405 * gst_caps_features_to_string:
406 * @features: a #GstCapsFeatures
408 * Converts @features to a human-readable string representation.
410 * For debugging purposes its easier to do something like this:
412 * GST_LOG ("features is %" GST_PTR_FORMAT, features);
414 * This prints the features in human readble form.
416 * Free-function: g_free
418 * Returns: (transfer full): a pointer to string allocated by g_malloc().
419 * g_free() after usage.
424 gst_caps_features_to_string (const GstCapsFeatures * features)
428 g_return_val_if_fail (features != NULL, NULL);
430 s = g_string_sized_new (FEATURES_ESTIMATED_STRING_LEN (features));
432 priv_gst_caps_features_append_to_gstring (features, s);
434 return g_string_free (s, FALSE);
438 priv_gst_caps_features_append_to_gstring (const GstCapsFeatures * features,
443 g_return_if_fail (features != NULL);
445 if (features->array->len == 0 && features->is_any) {
446 g_string_append (s, "ANY");
450 n = features->array->len;
451 for (i = 0; i < n; i++) {
452 GQuark *quark = &g_array_index (features->array, GQuark, i);
454 g_string_append (s, g_quark_to_string (*quark));
456 g_string_append (s, ", ");
461 * gst_caps_features_from_string:
462 * @features: a string representation of a #GstCapsFeatures.
464 * Creates a #GstCapsFeatures from a string representation.
466 * Free-function: gst_caps_features_free
468 * Returns: (transfer full): a new #GstCapsFeatures or NULL when the string could
469 * not be parsed. Free with gst_caps_features_free() after use.
474 gst_caps_features_from_string (const gchar * features)
476 GstCapsFeatures *ret;
477 gboolean escape = FALSE;
478 const gchar *features_orig = features;
479 const gchar *feature;
481 ret = gst_caps_features_new_empty ();
483 if (!features || *features == '\0')
486 if (strcmp (features, "ANY") == 0) {
491 /* Skip trailing spaces */
492 while (*features == ' ')
503 } else if ((!escape && c == ',') || c == '\0') {
504 guint len = features - feature + 1;
509 g_warning ("Failed deserialize caps features '%s'", features_orig);
510 gst_caps_features_free (ret);
514 tmp = g_malloc (len);
515 memcpy (tmp, feature, len - 1);
524 if (strstr (tmp, " ") != NULL || *tmp == '\0') {
526 g_warning ("Failed deserialize caps features '%s'", features_orig);
527 gst_caps_features_free (ret);
531 gst_caps_features_add (ret, tmp);
537 /* Skip to the next value */
539 while (*features == ' ')
552 * gst_caps_features_get_size:
553 * @features: a #GstCapsFeatures.
555 * Returns the number of features in @features.
557 * Returns: The number of features in @features.
562 gst_caps_features_get_size (const GstCapsFeatures * features)
564 g_return_val_if_fail (features != NULL, 0);
566 return features->array->len;
570 * gst_caps_features_get_nth:
571 * @features: a #GstCapsFeatures.
572 * @i: index of the feature
574 * Returns the @i-th feature of @features.
576 * Returns: The @i-th feature of @features.
581 gst_caps_features_get_nth (const GstCapsFeatures * features, guint i)
583 const gchar *feature;
586 g_return_val_if_fail (features != NULL, NULL);
588 quark = gst_caps_features_get_nth_id (features, i);
592 feature = g_quark_to_string (quark);
597 * gst_caps_features_get_nth_id:
598 * @features: a #GstCapsFeatures.
599 * @i: index of the feature
601 * Returns the @i-th feature of @features.
603 * Returns: The @i-th feature of @features.
608 gst_caps_features_get_nth_id (const GstCapsFeatures * features, guint i)
612 g_return_val_if_fail (features != NULL, 0);
613 g_return_val_if_fail (i < features->array->len, 0);
615 quark = &g_array_index (features->array, GQuark, i);
621 * gst_caps_features_contains:
622 * @features: a #GstCapsFeatures.
623 * @feature: a feature
625 * Check if @features contains @feature.
627 * Returns: %TRUE if @features contains @feature.
632 gst_caps_features_contains (const GstCapsFeatures * features,
633 const gchar * feature)
635 g_return_val_if_fail (features != NULL, FALSE);
636 g_return_val_if_fail (feature != NULL, FALSE);
638 return gst_caps_features_contains_id (features,
639 g_quark_from_string (feature));
643 * gst_caps_features_contains_id:
644 * @features: a #GstCapsFeatures.
645 * @feature: a feature
647 * Check if @features contains @feature.
649 * Returns: %TRUE if @features contains @feature.
654 gst_caps_features_contains_id (const GstCapsFeatures * features, GQuark feature)
658 g_return_val_if_fail (features != NULL, FALSE);
659 g_return_val_if_fail (feature != 0, FALSE);
661 if (features->is_any)
664 n = features->array->len;
666 return feature == _gst_caps_feature_memory_system_memory;
668 for (i = 0; i < n; i++) {
669 if (gst_caps_features_get_nth_id (features, i) == feature)
677 * gst_caps_features_is_equal:
678 * @features1: a #GstCapsFeatures.
679 * @features2: a #GstCapsFeatures.
681 * Check if @features1 and @features2 are equal.
683 * Returns: %TRUE if @features1 and @features2 are equal.
688 gst_caps_features_is_equal (const GstCapsFeatures * features1,
689 const GstCapsFeatures * features2)
693 g_return_val_if_fail (features1 != NULL, FALSE);
694 g_return_val_if_fail (features2 != NULL, FALSE);
696 if (features1->is_any || features2->is_any)
699 /* Check for the sysmem==empty case */
700 if (features1->array->len == 0 && features2->array->len == 0)
702 if (features1->array->len == 0 && features2->array->len == 1
703 && gst_caps_features_contains_id (features2,
704 _gst_caps_feature_memory_system_memory))
706 if (features2->array->len == 0 && features1->array->len == 1
707 && gst_caps_features_contains_id (features1,
708 _gst_caps_feature_memory_system_memory))
711 if (features1->array->len != features2->array->len)
714 n = features1->array->len;
715 for (i = 0; i < n; i++)
716 if (!gst_caps_features_contains_id (features2,
717 gst_caps_features_get_nth_id (features1, i)))
724 * gst_caps_features_is_any:
725 * @features: a #GstCapsFeatures.
727 * Check if @features is %GST_CAPS_FEATURES_ANY.
729 * Returns: %TRUE if @features is %GST_CAPS_FEATURES_ANY.
734 gst_caps_features_is_any (const GstCapsFeatures * features)
736 g_return_val_if_fail (features != NULL, FALSE);
738 return features->is_any;
742 * gst_caps_features_add:
743 * @features: a #GstCapsFeatures.
744 * @feature: a feature.
746 * Adds @feature to @features.
751 gst_caps_features_add (GstCapsFeatures * features, const gchar * feature)
753 g_return_if_fail (features != NULL);
754 g_return_if_fail (IS_MUTABLE (features));
755 g_return_if_fail (feature != NULL);
756 g_return_if_fail (!features->is_any);
758 gst_caps_features_add_id (features, g_quark_from_string (feature));
762 * gst_caps_features_add_id:
763 * @features: a #GstCapsFeatures.
764 * @feature: a feature.
766 * Adds @feature to @features.
771 gst_caps_features_add_id (GstCapsFeatures * features, GQuark feature)
773 g_return_if_fail (features != NULL);
774 g_return_if_fail (IS_MUTABLE (features));
775 g_return_if_fail (feature != 0);
776 g_return_if_fail (!features->is_any);
778 if (!gst_caps_feature_name_is_valid (g_quark_to_string (feature))) {
779 g_warning ("Invalid caps feature name: %s", g_quark_to_string (feature));
783 /* If features is empty it will contain sysmem, however
784 * we want to add it explicitely if it is tried to be
785 * added as first features
787 if (features->array->len > 0
788 && gst_caps_features_contains_id (features, feature))
791 g_array_append_val (features->array, feature);
795 * gst_caps_features_remove:
796 * @features: a #GstCapsFeatures.
797 * @feature: a feature.
799 * Removes @feature from @features.
804 gst_caps_features_remove (GstCapsFeatures * features, const gchar * feature)
806 g_return_if_fail (features != NULL);
807 g_return_if_fail (IS_MUTABLE (features));
808 g_return_if_fail (feature != NULL);
810 gst_caps_features_remove_id (features, g_quark_from_string (feature));
814 * gst_caps_features_remove_id:
815 * @features: a #GstCapsFeatures.
816 * @feature: a feature.
818 * Removes @feature from @features.
823 gst_caps_features_remove_id (GstCapsFeatures * features, GQuark feature)
827 g_return_if_fail (features != NULL);
828 g_return_if_fail (IS_MUTABLE (features));
829 g_return_if_fail (feature != 0);
831 n = features->array->len;
832 for (i = 0; i < n; i++) {
833 GQuark quark = gst_caps_features_get_nth_id (features, i);
835 if (quark == feature) {
836 g_array_remove_index_fast (features->array, i);
843 gst_caps_features_transform_to_string (const GValue * src_value,
846 g_return_if_fail (src_value != NULL);
847 g_return_if_fail (dest_value != NULL);
849 dest_value->data[0].v_pointer =
850 gst_caps_features_to_string (src_value->data[0].v_pointer);