2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
5 * gstcaps.c: Element capabilities subsystem
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
23 /* #define GST_DEBUG_ENABLED */
24 #include "gst_private.h"
29 static GMemChunk *_gst_caps_chunk;
30 static GMutex *_gst_caps_chunk_lock;
35 _gst_caps_initialize (void)
37 _gst_caps_chunk = g_mem_chunk_new ("GstCaps",
38 sizeof (GstCaps), sizeof (GstCaps) * 256,
40 _gst_caps_chunk_lock = g_mutex_new ();
42 _gst_caps_type = g_boxed_type_register_static ("GstCaps",
43 (GBoxedCopyFunc) gst_caps_ref,
44 (GBoxedFreeFunc) gst_caps_unref);
49 get_type_for_mime (const gchar *mime)
53 typeid = gst_type_find_by_mime (mime);
55 GstTypeDefinition definition;
56 GstTypeFactory *factory;
58 definition.name = "capstype";
59 definition.mime = g_strdup (mime);
60 definition.exts = NULL;
61 definition.typefindfunc = NULL;
63 factory = gst_typefactory_new (&definition);
65 typeid = gst_type_register (factory);
72 * @name: the name of this capability
73 * @mime: the mime type to attach to the capability
74 * @props: the properties to add to this capability
76 * Create a new capability with the given mime typei and properties.
78 * Returns: a new capability
81 gst_caps_new (const gchar *name, const gchar *mime, GstProps *props)
83 g_return_val_if_fail (mime != NULL, NULL);
85 return gst_caps_new_id (name, get_type_for_mime (mime), props);
90 * @name: the name of this capability
91 * @id: the id of the mime type
92 * @props: the properties to add to this capability
94 * Create a new capability with the given mime typeid and properties.
96 * Returns: a new capability
99 gst_caps_new_id (const gchar *name, const guint16 id, GstProps *props)
103 g_mutex_lock (_gst_caps_chunk_lock);
104 caps = g_mem_chunk_alloc (_gst_caps_chunk);
105 g_mutex_unlock (_gst_caps_chunk_lock);
107 caps->name = g_strdup (name);
109 caps->properties = props;
113 caps->fixed = props->fixed;
122 * @caps: the caps to destroy
124 * Frees the memory used by this caps structure and all
125 * the chained caps and properties.
128 gst_caps_destroy (GstCaps *caps)
137 gst_props_unref (caps->properties);
139 g_mutex_lock (_gst_caps_chunk_lock);
140 g_mem_chunk_free (_gst_caps_chunk, caps);
141 g_mutex_unlock (_gst_caps_chunk_lock);
144 gst_caps_unref (next);
149 * @caps: the caps to print out
150 * @label: a label to put on the printout, or NULL
152 * Print out the contents of the caps structure. Useful for debugging.
155 gst_caps_debug (GstCaps *caps, const gchar *label)
157 GST_DEBUG_ENTER ("caps debug: %s", label);
159 GST_DEBUG (GST_CAT_CAPS, "caps: %p %s %s", caps, caps->name, gst_caps_get_mime (caps));
161 if (caps->properties) {
162 gst_props_debug (caps->properties);
165 GST_DEBUG (GST_CAT_CAPS, "no properties");
170 GST_DEBUG_LEAVE ("caps debug");
175 * @caps: the caps to unref
177 * Decrease the refcount of this caps structure,
178 * destroying it when the refcount is 0
180 * Returns: caps or NULL if the refcount reached 0
183 gst_caps_unref (GstCaps *caps)
191 g_return_val_if_fail (caps->refcount > 0, NULL);
194 zero = (caps->refcount == 0);
198 *next = gst_caps_unref (*next);
201 gst_caps_destroy (caps);
209 * @caps: the caps to ref
211 * Increase the refcount of this caps structure
213 * Returns: the caps with the refcount incremented
216 gst_caps_ref (GstCaps *caps)
218 g_return_val_if_fail (caps != NULL, NULL);
227 * @caps: the caps to copy
229 * Copies the caps, not copying any chained caps.
231 * Returns: a copy of the GstCaps structure.
234 gst_caps_copy_1 (GstCaps *caps)
241 newcaps = gst_caps_new_id (
244 gst_props_copy (caps->properties));
251 * @caps: the caps to copy
255 * Returns: a copy of the GstCaps structure.
258 gst_caps_copy (GstCaps *caps)
260 GstCaps *new = NULL, *walk = NULL;
265 newcaps = gst_caps_copy_1 (caps);
268 new = walk = newcaps;
271 walk = walk->next = newcaps;
280 * gst_caps_copy_on_write:
281 * @caps: the caps to copy
283 * Copies the caps if the refcount is greater than 1
285 * Returns: a pointer to a GstCaps strcuture that can
286 * be safely written to
289 gst_caps_copy_on_write (GstCaps *caps)
294 g_return_val_if_fail (caps != NULL, NULL);
296 needcopy = (caps->refcount > 1);
299 new = gst_caps_copy (caps);
300 gst_caps_unref (caps);
308 * @caps: the caps to get the name from
310 * Get the name of a GstCaps structure.
312 * Returns: the name of the caps
315 gst_caps_get_name (GstCaps *caps)
317 g_return_val_if_fail (caps != NULL, NULL);
319 return (const gchar *)caps->name;
324 * @caps: the caps to set the name to
325 * @name: the name to set
327 * Set the name of a caps.
330 gst_caps_set_name (GstCaps *caps, const gchar *name)
332 g_return_if_fail (caps != NULL);
337 caps->name = g_strdup (name);
342 * @caps: the caps to get the mime type from
344 * Get the mime type of the caps as a string.
346 * Returns: the mime type of the caps
349 gst_caps_get_mime (GstCaps *caps)
353 g_return_val_if_fail (caps != NULL, NULL);
355 type = gst_type_find_by_id (caps->id);
360 return "unknown/unknown";
365 * @caps: the caps to set the mime type to
366 * @mime: the mime type to attach to the caps
368 * Set the mime type of the caps as a string.
371 gst_caps_set_mime (GstCaps *caps, const gchar *mime)
373 g_return_if_fail (caps != NULL);
374 g_return_if_fail (mime != NULL);
376 caps->id = get_type_for_mime (mime);
380 * gst_caps_get_type_id:
381 * @caps: the caps to get the type id from
383 * Get the type id of the caps.
385 * Returns: the type id of the caps
388 gst_caps_get_type_id (GstCaps *caps)
390 g_return_val_if_fail (caps != NULL, 0);
396 * gst_caps_set_type_id:
397 * @caps: the caps to set the type id to
398 * @type_id: the type id to set
400 * Set the type id of the caps.
403 gst_caps_set_type_id (GstCaps *caps, guint16 type_id)
405 g_return_if_fail (caps != NULL);
411 * gst_caps_set_props:
412 * @caps: the caps to attach the properties to
413 * @props: the properties to attach
415 * Set the properties to the given caps.
417 * Returns: the new caps structure
420 gst_caps_set_props (GstCaps *caps, GstProps *props)
422 g_return_val_if_fail (caps != NULL, caps);
423 g_return_val_if_fail (props != NULL, caps);
424 g_return_val_if_fail (caps->properties == NULL, caps);
426 caps->properties = props;
432 * gst_caps_get_props:
433 * @caps: the caps to get the properties from
435 * Get the properties of the given caps.
437 * Returns: the properties of the caps
440 gst_caps_get_props (GstCaps *caps)
442 g_return_val_if_fail (caps != NULL, NULL);
444 return caps->properties;
450 * @...: more capabilities
452 * chains the given capabilities
454 * Returns: the new capability
457 gst_caps_chain (GstCaps *caps, ...)
459 GstCaps *orig = caps;
462 va_start (var_args, caps);
467 toadd = va_arg (var_args, GstCaps*);
468 gst_caps_append (caps, toadd);
480 * @capstoadd: the capability to append
482 * Appends a capability to the existing capability.
484 * Returns: the new capability
487 gst_caps_append (GstCaps *caps, GstCaps *capstoadd)
489 GstCaps *orig = caps;
491 if (caps == NULL || caps == capstoadd)
497 caps->next = capstoadd;
505 * @capstoadd: a capabilty to prepend
507 * prepend the capability to the list of capabilities
509 * Returns: the new capability
512 gst_caps_prepend (GstCaps *caps, GstCaps *capstoadd)
514 GstCaps *orig = capstoadd;
516 if (capstoadd == NULL)
519 g_return_val_if_fail (caps != capstoadd, caps);
521 while (capstoadd->next) {
522 capstoadd = capstoadd->next;
524 capstoadd->next = caps;
530 * gst_caps_get_by_name:
532 * @name: the name of the capability to get
534 * Get the capability with the given name from this
535 * chain of capabilities.
537 * Returns: the first capability in the chain with the
541 gst_caps_get_by_name (GstCaps *caps, const gchar *name)
543 g_return_val_if_fail (caps != NULL, NULL);
544 g_return_val_if_fail (name != NULL, NULL);
547 if (!strcmp (caps->name, name))
556 gst_caps_check_compatibility_func (GstCaps *fromcaps, GstCaps *tocaps)
558 if (fromcaps->id != tocaps->id) {
559 GST_DEBUG (GST_CAT_CAPS,"mime types differ (%s to %s)",
560 gst_type_find_by_id (fromcaps->id)->mime,
561 gst_type_find_by_id (tocaps->id)->mime);
565 if (tocaps->properties) {
566 if (fromcaps->properties) {
567 return gst_props_check_compatibility (fromcaps->properties, tocaps->properties);
570 GST_DEBUG (GST_CAT_CAPS,"no source caps");
575 /* assume it accepts everything */
576 GST_DEBUG (GST_CAT_CAPS,"no caps");
582 * gst_caps_check_compatibility:
583 * @fromcaps: a capabilty
584 * @tocaps: a capabilty
586 * Checks whether two capabilities are compatible.
588 * Returns: TRUE if compatible, FALSE otherwise
591 gst_caps_check_compatibility (GstCaps *fromcaps, GstCaps *tocaps)
593 if (fromcaps == NULL) {
594 if (tocaps == NULL) {
595 GST_DEBUG (GST_CAT_CAPS,"no caps");
599 GST_DEBUG (GST_CAT_CAPS,"no source but destination caps");
604 if (tocaps == NULL) {
605 GST_DEBUG (GST_CAT_CAPS,"source caps and no destination caps");
611 GstCaps *destcaps = tocaps;
614 if (gst_caps_check_compatibility_func (fromcaps, destcaps))
617 destcaps = destcaps->next;
619 fromcaps = fromcaps->next;
625 gst_caps_intersect_func (GstCaps *caps1, GstCaps *caps2)
627 GstCaps *result = NULL;
630 if (caps1->id != caps2->id) {
631 GST_DEBUG (GST_CAT_CAPS,"mime types differ (%s to %s)",
632 gst_type_find_by_id (caps1->id)->mime,
633 gst_type_find_by_id (caps2->id)->mime);
637 if (caps1->properties == NULL) {
638 return gst_caps_ref (caps2);
640 if (caps2->properties == NULL) {
641 return gst_caps_ref (caps1);
644 props = gst_props_intersect (caps1->properties, caps2->properties);
646 result = gst_caps_new_id ("intersect", caps1->id, props);
653 * gst_caps_intersect:
654 * @caps1: a capabilty
655 * @caps2: a capabilty
657 * Make the intersection between two caps.
659 * Returns: The intersection of the two caps or NULL if the intersection
663 gst_caps_intersect (GstCaps *caps1, GstCaps *caps2)
665 GstCaps *result = NULL, *walk = NULL;
668 GST_DEBUG (GST_CAT_CAPS, "first caps is NULL, return other caps");
669 return gst_caps_copy (caps2);
672 GST_DEBUG (GST_CAT_CAPS, "second caps is NULL, return other caps");
673 return gst_caps_copy (caps1);
677 GstCaps *othercaps = caps2;
680 GstCaps *intersection;
682 intersection = gst_caps_intersect_func (caps1, othercaps);
686 walk = result = intersection;
689 walk = walk->next = intersection;
692 othercaps = othercaps->next;
701 * gst_caps_normalize:
704 * Make the normalisation of the caps. This will return a new caps
705 * that is equivalent to the input caps with the exception that all
706 * lists are unrolled. This function is useful when you want to iterate
709 * Returns: The normalisation of the caps.
712 gst_caps_normalize (GstCaps *caps)
714 GstCaps *result = NULL, *walk = caps;
722 proplist = gst_props_normalize (caps->properties);
723 if (proplist && g_list_next (proplist) == NULL) {
725 walk = result = caps;
727 walk = walk->next = caps;
733 GstProps *props = (GstProps *) proplist->data;
734 GstCaps *newcaps = gst_caps_new_id (caps->name, caps->id, props);
737 walk = result = newcaps;
739 walk = walk->next = newcaps;
741 proplist = g_list_next (proplist);
749 #ifndef GST_DISABLE_LOADSAVE_REGISTRY
751 * gst_caps_save_thyself:
752 * @caps: a capabilty to save
753 * @parent: the parent XML node pointer
755 * Save the capability into an XML representation.
757 * Returns: a new XML node pointer
760 gst_caps_save_thyself (GstCaps *caps, xmlNodePtr parent)
763 xmlNodePtr subsubtree;
766 subtree = xmlNewChild (parent, NULL, "capscomp", NULL);
768 xmlNewChild (subtree, NULL, "name", caps->name);
769 xmlNewChild (subtree, NULL, "type", gst_type_find_by_id (caps->id)->mime);
770 if (caps->properties) {
771 subsubtree = xmlNewChild (subtree, NULL, "properties", NULL);
773 gst_props_save_thyself (caps->properties, subsubtree);
783 * gst_caps_load_thyself:
784 * @parent: the parent XML node pointer
786 * Load a new caps from the XML representation.
788 * Returns: a new capability
791 gst_caps_load_thyself (xmlNodePtr parent)
793 GstCaps *result = NULL;
794 xmlNodePtr field = parent->xmlChildrenNode;
797 if (!strcmp (field->name, "capscomp")) {
798 xmlNodePtr subfield = field->xmlChildrenNode;
802 g_mutex_lock (_gst_caps_chunk_lock);
803 caps = g_mem_chunk_alloc0 (_gst_caps_chunk);
804 g_mutex_unlock (_gst_caps_chunk_lock);
811 if (!strcmp (subfield->name, "name")) {
812 caps->name = xmlNodeGetContent (subfield);
814 if (!strcmp (subfield->name, "type")) {
815 content = xmlNodeGetContent (subfield);
816 caps->id = get_type_for_mime (content);
819 else if (!strcmp (subfield->name, "properties")) {
820 caps->properties = gst_props_load_thyself (subfield);
823 subfield = subfield->next;
825 result = gst_caps_append (result, caps);
833 #endif /* GST_DISABLE_LOADSAVE_REGISTRY */