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_type_factory_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 (%sfixed)", caps, caps->name, gst_caps_get_mime (caps),
160 caps->fixed ? "" : "NOT ");
162 if (caps->properties) {
163 gst_props_debug (caps->properties);
166 GST_DEBUG (GST_CAT_CAPS, "no properties");
171 GST_DEBUG_LEAVE ("caps debug");
176 * @caps: the caps to unref
178 * Decrease the refcount of this caps structure,
179 * destroying it when the refcount is 0
181 * Returns: caps or NULL if the refcount reached 0
184 gst_caps_unref (GstCaps *caps)
192 g_return_val_if_fail (caps->refcount > 0, NULL);
195 zero = (caps->refcount == 0);
199 *next = gst_caps_unref (*next);
202 gst_caps_destroy (caps);
210 * @caps: the caps to ref
212 * Increase the refcount of this caps structure
214 * Returns: the caps with the refcount incremented
217 gst_caps_ref (GstCaps *caps)
219 g_return_val_if_fail (caps != NULL, NULL);
228 * @caps: the caps to copy
230 * Copies the caps, not copying any chained caps.
232 * Returns: a copy of the GstCaps structure.
235 gst_caps_copy_1 (GstCaps *caps)
242 newcaps = gst_caps_new_id (
245 gst_props_copy (caps->properties));
252 * @caps: the caps to copy
256 * Returns: a copy of the GstCaps structure.
259 gst_caps_copy (GstCaps *caps)
261 GstCaps *new = NULL, *walk = NULL;
266 newcaps = gst_caps_copy_1 (caps);
269 new = walk = newcaps;
272 walk = walk->next = newcaps;
281 * gst_caps_copy_on_write:
282 * @caps: the caps to copy
284 * Copies the caps if the refcount is greater than 1
286 * Returns: a pointer to a GstCaps strcuture that can
287 * be safely written to
290 gst_caps_copy_on_write (GstCaps *caps)
295 g_return_val_if_fail (caps != NULL, NULL);
297 needcopy = (caps->refcount > 1);
300 new = gst_caps_copy (caps);
301 gst_caps_unref (caps);
309 * @caps: the caps to get the name from
311 * Get the name of a GstCaps structure.
313 * Returns: the name of the caps
316 gst_caps_get_name (GstCaps *caps)
318 g_return_val_if_fail (caps != NULL, NULL);
320 return (const gchar *)caps->name;
325 * @caps: the caps to set the name to
326 * @name: the name to set
328 * Set the name of a caps.
331 gst_caps_set_name (GstCaps *caps, const gchar *name)
333 g_return_if_fail (caps != NULL);
338 caps->name = g_strdup (name);
343 * @caps: the caps to get the mime type from
345 * Get the mime type of the caps as a string.
347 * Returns: the mime type of the caps
350 gst_caps_get_mime (GstCaps *caps)
354 g_return_val_if_fail (caps != NULL, NULL);
356 type = gst_type_find_by_id (caps->id);
361 return "unknown/unknown";
366 * @caps: the caps to set the mime type to
367 * @mime: the mime type to attach to the caps
369 * Set the mime type of the caps as a string.
372 gst_caps_set_mime (GstCaps *caps, const gchar *mime)
374 g_return_if_fail (caps != NULL);
375 g_return_if_fail (mime != NULL);
377 caps->id = get_type_for_mime (mime);
381 * gst_caps_get_type_id:
382 * @caps: the caps to get the type id from
384 * Get the type id of the caps.
386 * Returns: the type id of the caps
389 gst_caps_get_type_id (GstCaps *caps)
391 g_return_val_if_fail (caps != NULL, 0);
397 * gst_caps_set_type_id:
398 * @caps: the caps to set the type id to
399 * @type_id: the type id to set
401 * Set the type id of the caps.
404 gst_caps_set_type_id (GstCaps *caps, guint16 type_id)
406 g_return_if_fail (caps != NULL);
412 * gst_caps_set_props:
413 * @caps: the caps to attach the properties to
414 * @props: the properties to attach
416 * Set the properties to the given caps.
418 * Returns: the new caps structure
421 gst_caps_set_props (GstCaps *caps, GstProps *props)
423 g_return_val_if_fail (caps != NULL, caps);
424 g_return_val_if_fail (props != NULL, caps);
425 g_return_val_if_fail (caps->properties == NULL, caps);
427 caps->properties = props;
433 * gst_caps_get_props:
434 * @caps: the caps to get the properties from
436 * Get the properties of the given caps.
438 * Returns: the properties of the caps
441 gst_caps_get_props (GstCaps *caps)
443 g_return_val_if_fail (caps != NULL, NULL);
445 return caps->properties;
451 * @...: more capabilities
453 * chains the given capabilities
455 * Returns: the new capability
458 gst_caps_chain (GstCaps *caps, ...)
460 GstCaps *orig = caps;
463 va_start (var_args, caps);
468 toadd = va_arg (var_args, GstCaps*);
469 gst_caps_append (caps, toadd);
481 * @capstoadd: the capability to append
483 * Appends a capability to the existing capability.
485 * Returns: the new capability
488 gst_caps_append (GstCaps *caps, GstCaps *capstoadd)
490 GstCaps *orig = caps;
492 if (caps == NULL || caps == capstoadd)
498 caps->next = capstoadd;
506 * @capstoadd: a capabilty to prepend
508 * prepend the capability to the list of capabilities
510 * Returns: the new capability
513 gst_caps_prepend (GstCaps *caps, GstCaps *capstoadd)
515 GstCaps *orig = capstoadd;
517 if (capstoadd == NULL)
520 g_return_val_if_fail (caps != capstoadd, caps);
522 while (capstoadd->next) {
523 capstoadd = capstoadd->next;
525 capstoadd->next = caps;
531 * gst_caps_get_by_name:
533 * @name: the name of the capability to get
535 * Get the capability with the given name from this
536 * chain of capabilities.
538 * Returns: the first capability in the chain with the
542 gst_caps_get_by_name (GstCaps *caps, const gchar *name)
544 g_return_val_if_fail (caps != NULL, NULL);
545 g_return_val_if_fail (name != NULL, NULL);
548 if (!strcmp (caps->name, name))
557 gst_caps_check_compatibility_func (GstCaps *fromcaps, GstCaps *tocaps)
559 if (fromcaps->id != tocaps->id) {
560 GST_DEBUG (GST_CAT_CAPS,"mime types differ (%s to %s)",
561 gst_type_find_by_id (fromcaps->id)->mime,
562 gst_type_find_by_id (tocaps->id)->mime);
566 if (tocaps->properties) {
567 if (fromcaps->properties) {
568 return gst_props_check_compatibility (fromcaps->properties, tocaps->properties);
571 GST_DEBUG (GST_CAT_CAPS,"no source caps");
576 /* assume it accepts everything */
577 GST_DEBUG (GST_CAT_CAPS,"no caps");
583 * gst_caps_check_compatibility:
584 * @fromcaps: a capabilty
585 * @tocaps: a capabilty
587 * Checks whether two capabilities are compatible.
589 * Returns: TRUE if compatible, FALSE otherwise
592 gst_caps_check_compatibility (GstCaps *fromcaps, GstCaps *tocaps)
594 if (fromcaps == NULL) {
595 if (tocaps == NULL) {
596 GST_DEBUG (GST_CAT_CAPS,"no caps");
600 GST_DEBUG (GST_CAT_CAPS,"no source but destination caps");
605 if (tocaps == NULL) {
606 GST_DEBUG (GST_CAT_CAPS,"source caps and no destination caps");
612 GstCaps *destcaps = tocaps;
615 if (gst_caps_check_compatibility_func (fromcaps, destcaps))
618 destcaps = destcaps->next;
620 fromcaps = fromcaps->next;
626 gst_caps_intersect_func (GstCaps *caps1, GstCaps *caps2)
628 GstCaps *result = NULL;
631 if (caps1->id != caps2->id) {
632 GST_DEBUG (GST_CAT_CAPS,"mime types differ (%s to %s)",
633 gst_type_find_by_id (caps1->id)->mime,
634 gst_type_find_by_id (caps2->id)->mime);
638 if (caps1->properties == NULL) {
639 return gst_caps_ref (caps2);
641 if (caps2->properties == NULL) {
642 return gst_caps_ref (caps1);
645 props = gst_props_intersect (caps1->properties, caps2->properties);
647 result = gst_caps_new_id ("intersect", caps1->id, props);
654 * gst_caps_intersect:
655 * @caps1: a capabilty
656 * @caps2: a capabilty
658 * Make the intersection between two caps.
660 * Returns: The intersection of the two caps or NULL if the intersection
664 gst_caps_intersect (GstCaps *caps1, GstCaps *caps2)
666 GstCaps *result = NULL, *walk = NULL;
669 GST_DEBUG (GST_CAT_CAPS, "first caps is NULL, return other caps");
670 return gst_caps_copy (caps2);
673 GST_DEBUG (GST_CAT_CAPS, "second caps is NULL, return other caps");
674 return gst_caps_copy (caps1);
678 GstCaps *othercaps = caps2;
681 GstCaps *intersection;
683 intersection = gst_caps_intersect_func (caps1, othercaps);
687 walk = result = intersection;
690 walk = walk->next = intersection;
693 othercaps = othercaps->next;
702 * gst_caps_normalize:
705 * Make the normalisation of the caps. This will return a new caps
706 * that is equivalent to the input caps with the exception that all
707 * lists are unrolled. This function is useful when you want to iterate
710 * Returns: The normalisation of the caps.
713 gst_caps_normalize (GstCaps *caps)
715 GstCaps *result = NULL, *walk = caps;
723 proplist = gst_props_normalize (caps->properties);
724 if (proplist && g_list_next (proplist) == NULL) {
726 walk = result = caps;
728 walk = walk->next = caps;
734 GstProps *props = (GstProps *) proplist->data;
735 GstCaps *newcaps = gst_caps_new_id (caps->name, caps->id, props);
738 walk = result = newcaps;
740 walk = walk->next = newcaps;
742 proplist = g_list_next (proplist);
750 #ifndef GST_DISABLE_LOADSAVE_REGISTRY
752 * gst_caps_save_thyself:
753 * @caps: a capabilty to save
754 * @parent: the parent XML node pointer
756 * Save the capability into an XML representation.
758 * Returns: a new XML node pointer
761 gst_caps_save_thyself (GstCaps *caps, xmlNodePtr parent)
764 xmlNodePtr subsubtree;
767 subtree = xmlNewChild (parent, NULL, "capscomp", NULL);
769 xmlNewChild (subtree, NULL, "name", caps->name);
770 xmlNewChild (subtree, NULL, "type", gst_type_find_by_id (caps->id)->mime);
771 if (caps->properties) {
772 subsubtree = xmlNewChild (subtree, NULL, "properties", NULL);
774 gst_props_save_thyself (caps->properties, subsubtree);
784 * gst_caps_load_thyself:
785 * @parent: the parent XML node pointer
787 * Load a new caps from the XML representation.
789 * Returns: a new capability
792 gst_caps_load_thyself (xmlNodePtr parent)
794 GstCaps *result = NULL;
795 xmlNodePtr field = parent->xmlChildrenNode;
798 if (!strcmp (field->name, "capscomp")) {
799 xmlNodePtr subfield = field->xmlChildrenNode;
803 g_mutex_lock (_gst_caps_chunk_lock);
804 caps = g_mem_chunk_alloc0 (_gst_caps_chunk);
805 g_mutex_unlock (_gst_caps_chunk_lock);
812 if (!strcmp (subfield->name, "name")) {
813 caps->name = xmlNodeGetContent (subfield);
815 if (!strcmp (subfield->name, "type")) {
816 content = xmlNodeGetContent (subfield);
817 caps->id = get_type_for_mime (content);
820 else if (!strcmp (subfield->name, "properties")) {
821 caps->properties = gst_props_load_thyself (subfield);
824 subfield = subfield->next;
826 result = gst_caps_append (result, caps);
834 #endif /* GST_DISABLE_LOADSAVE_REGISTRY */