gstreamer/gst/gstcaps.c

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstcaps.c: Element capabilities subsystem
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
//#define GST_DEBUG_ENABLED
#include "gst_private.h"
#include "gstcaps.h"
#include "gsttype.h"
#include "gstpropsprivate.h"
void
_gst_caps_initialize (void)
{
}
static guint16
get_type_for_mime (const gchar *mime)
{
guint16 typeid;
typeid = gst_type_find_by_mime (mime);
if (typeid == 0) {
GstTypeFactory factory; // = g_new0 (GstTypeFactory, 1);
factory.mime = g_strdup (mime);
factory.exts = NULL;
factory.typefindfunc = NULL;
typeid = gst_type_register (&factory);
}
return typeid;
}
/**
* gst_caps_new:
* @name: the name of this capability
* @mime: the mime type to attach to the capability
*
* Create a new capability with the given mime type.
*
* Returns: a new capability
*/
GstCaps*
gst_caps_new (const gchar *name, const gchar *mime)
{
GstCaps *caps;
g_return_val_if_fail (mime != NULL, NULL);
caps = g_new0 (GstCaps, 1);
caps->name = g_strdup (name);
caps->id = get_type_for_mime (mime);
caps->properties = NULL;
caps->next = NULL;
return caps;
}
/**
* gst_caps_new_with_props:
* @name: the name of this capability
* @mime: the mime type to attach to the capability
* @props: the properties for this capability
*
* Create a new capability with the given mime type and the given properties.
*
* Returns: a new capability
*/
GstCaps*
gst_caps_new_with_props (const gchar *name, const gchar *mime, GstProps *props)
{
GstCaps *caps;
caps = gst_caps_new (name, mime);
caps->properties = props;
return caps;
}
/**
* gst_caps_register:
* @factory: the factory to register
*
* Register the factory.
*
* Returns: the registered capability
*/
GstCaps*
gst_caps_register (GstCapsFactory *factory)
{
guint dummy;
return gst_caps_register_count (factory, &dummy);
}
/**
* gst_caps_register_count:
* @factory: the factory to register
* @counter: count how many entries were consumed
*
* Register the factory.
*
* Returns: the registered capability
*/
GstCaps*
gst_caps_register_count (GstCapsFactory *factory, guint *counter)
{
GstCapsFactoryEntry tag;
gint i = 0;
guint16 typeid;
gchar *name;
GstCaps *caps;
g_return_val_if_fail (factory != NULL, NULL);
tag = (*factory)[i++];
g_return_val_if_fail (tag != NULL, NULL);
name = tag;
tag = (*factory)[i++];
g_return_val_if_fail (tag != NULL, NULL);
typeid = get_type_for_mime ((gchar *)tag);
caps = g_new0 (GstCaps, 1);
g_return_val_if_fail (caps != NULL, NULL);
caps->name = g_strdup (name);
caps->id = typeid;
caps->properties = gst_props_register_count (&(*factory)[i], counter);
*counter += 2;
return caps;
}
/**
* gst_caps_get_name:
* @caps: the caps to get the name from
*
* Get the name of a GstCaps structure.
*
* Returns: the name of the caps
*/
const gchar*
gst_caps_get_name (GstCaps *caps)
{
g_return_val_if_fail (caps != NULL, NULL);
return (const gchar *)caps->name;
}
/**
* gst_caps_set_name:
* @caps: the caps to set the name to
* @name: the name to set
*
* Set the name of a caps.
*/
void
gst_caps_set_name (GstCaps *caps, const gchar *name)
{
g_return_if_fail (caps != NULL);
if (caps->name)
g_free (caps->name);
caps->name = g_strdup (name);
}
/**
* gst_caps_get_mime:
* @caps: the caps to get the mime type from
*
* Get the mime type of the caps as a string.
*
* Returns: the mime type of the caps
*/
const gchar*
gst_caps_get_mime (GstCaps *caps)
{
GstType *type;
g_return_val_if_fail (caps != NULL, NULL);
type = gst_type_find_by_id (caps->id);
if (type)
return type->mime;
else
return "unknown/unknown";
}
/**
* gst_caps_set_mime:
* @caps: the caps to set the mime type to
* @mime: the mime type to attach to the caps
*
* Set the mime type of the caps as a string.
*/
void
gst_caps_set_mime (GstCaps *caps, const gchar *mime)
{
g_return_if_fail (caps != NULL);
g_return_if_fail (mime != NULL);
caps->id = get_type_for_mime (mime);
}
/**
* gst_caps_get_type_id:
* @caps: the caps to get the type id from
*
* Get the type id of the caps.
*
* Returns: the type id of the caps
*/
guint16
gst_caps_get_type_id (GstCaps *caps)
{
g_return_val_if_fail (caps != NULL, 0);
return caps->id;
}
/**
* gst_caps_set_type_id:
* @caps: the caps to set the type id to
* @typeid: the type id to set
*
* Set the type id of the caps.
*/
void
gst_caps_set_type_id (GstCaps *caps, guint16 type_id)
{
g_return_if_fail (caps != NULL);
caps->id = type_id;
}
/**
* gst_caps_set_props:
* @caps: the caps to attach the properties to
* @props: the properties to attach
*
* Set the properties to the given caps.
*
* Returns: the new caps structure
*/
GstCaps*
gst_caps_set_props (GstCaps *caps, GstProps *props)
{
g_return_val_if_fail (caps != NULL, caps);
g_return_val_if_fail (props != NULL, caps);
g_return_val_if_fail (caps->properties == NULL, caps);
caps->properties = props;
return caps;
}
/**
* gst_caps_get_props:
* @caps: the caps to get the properties from
*
* Get the properties of the given caps.
*
* Returns: the properties of the caps
*/
GstProps*
gst_caps_get_props (GstCaps *caps)
{
g_return_val_if_fail (caps != NULL, NULL);
return caps->properties;
}
/**
* gst_caps_append:
* @caps: a capabilty
* @capstoadd: the capability to append
*
* Appends a capability to the existing capability.
*
* Returns: the new capability
*/
GstCaps*
gst_caps_append (GstCaps *caps, GstCaps *capstoadd)
{
GstCaps *orig = caps;
if (caps == NULL)
return capstoadd;
while (caps->next) {
caps = caps->next;
}
caps->next = capstoadd;
return orig;
}
/**
* gst_caps_prepend:
* @caps: a capabilty
* @capstoadd: a capabilty to prepend
*
* prepend the capability to the list of capabilities
*
* Returns: the new capability
*/
GstCaps*
gst_caps_prepend (GstCaps *caps, GstCaps *capstoadd)
{
GstCaps *orig = capstoadd;
if (capstoadd == NULL)
return caps;
while (capstoadd->next) {
capstoadd = capstoadd->next;
}
capstoadd->next = caps;
return orig;
}
GstCaps*
gst_caps_get_by_name (GstCaps *caps, const gchar *name)
{
g_return_val_if_fail (caps != NULL, NULL);
g_return_val_if_fail (name != NULL, NULL);
while (caps) {
if (!strcmp (caps->name, name))
return caps;
caps = caps->next;
}
return NULL;
}
static gboolean
gst_caps_check_compatibility_func (GstCaps *fromcaps, GstCaps *tocaps)
{
if (fromcaps->id != tocaps->id) {
GST_DEBUG (0,"gstcaps: mime types differ (%d to %d)\n",
fromcaps->id, tocaps->id);
return FALSE;
}
if (tocaps->properties) {
if (fromcaps->properties) {
return gst_props_check_compatibility (fromcaps->properties, tocaps->properties);
}
else {
GST_DEBUG (0,"gstcaps: no source caps\n");
return FALSE;
}
}
else {
// assume it accepts everything
GST_DEBUG (0,"gstcaps: no caps\n");
return TRUE;
}
}
/**
* gst_caps_list_check_compatibility:
* @fromcaps: a capabilty
* @tocaps: a capabilty
*
* Checks whether two capability lists are compatible.
*
* Returns: TRUE if compatible, FALSE otherwise
*/
gboolean
gst_caps_check_compatibility (GstCaps *fromcaps, GstCaps *tocaps)
{
if (fromcaps == NULL ||
tocaps == NULL) {
GST_DEBUG (0,"gstcaps: no caps\n");
return TRUE;
}
while (fromcaps) {
GstCaps *destcaps = tocaps;
while (destcaps) {
if (gst_caps_check_compatibility_func (fromcaps, destcaps))
return TRUE;
destcaps = destcaps->next;
}
fromcaps = fromcaps->next;
}
return FALSE;
}
/**
* gst_caps_save_thyself:
* @caps: a capabilty to save
* @parent: the parent XML node pointer
*
* Save the capability into an XML representation.
*
* Returns: a new XML node pointer
*/
xmlNodePtr
gst_caps_save_thyself (GstCaps *caps, xmlNodePtr parent)
{
xmlNodePtr subtree;
xmlNodePtr subsubtree;
while (caps) {
subtree = xmlNewChild (parent, NULL, "capscomp", NULL);
xmlNewChild (subtree, NULL, "name", caps->name);
xmlNewChild (subtree, NULL, "type", gst_type_find_by_id (caps->id)->mime);
if (caps->properties) {
subsubtree = xmlNewChild (subtree, NULL, "properties", NULL);
gst_props_save_thyself (caps->properties, subsubtree);
}
caps = caps->next;
}
return parent;
}
/**
* gst_caps_load_thyself:
* @parent: the parent XML node pointer
*
* Load a new caps from the XML representation.
*
* Returns: a new capability
*/
GstCaps*
gst_caps_load_thyself (xmlNodePtr parent)
{
GstCaps *result = NULL;
xmlNodePtr field = parent->xmlChildrenNode;
while (field) {
if (!strcmp (field->name, "capscomp")) {
xmlNodePtr subfield = field->xmlChildrenNode;
GstCaps *caps = g_new0 (GstCaps, 1);
gchar *content;
while (subfield) {
if (!strcmp (subfield->name, "name")) {
caps->name = xmlNodeGetContent (subfield);
}
if (!strcmp (subfield->name, "type")) {
content = xmlNodeGetContent (subfield);
caps->id = get_type_for_mime (content);
g_free (content);
}
else if (!strcmp (subfield->name, "properties")) {
caps->properties = gst_props_load_thyself (subfield);
}
subfield = subfield->next;
}
result = gst_caps_append (result, caps);
}
field = field->next;
}
return result;
}