gstreamer/gst/gstcaps.c
Wim Taymans b2ee38575d Landed the new improved capsnegotiation system.
Original commit message from CVS:
Landed the new improved capsnegotiation system.
The main idea is to keep track of the possible data types that can
pass through a connection. plugins can at any time inspect, adjust and
refine these caps. plugins also get notified when something changes to
the types so that they can reconfigure themselves.
Look at the updated plugins and the soon to be finished doc.
2002-01-13 22:22:42 +00:00

800 lines
16 KiB
C

/* 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"
static GMemChunk *_gst_caps_chunk;
static GMutex *_gst_caps_chunk_lock;
void
_gst_caps_initialize (void)
{
_gst_caps_chunk = g_mem_chunk_new ("GstCaps",
sizeof (GstCaps), sizeof (GstCaps) * 256,
G_ALLOC_AND_FREE);
_gst_caps_chunk_lock = g_mutex_new ();
}
static guint16
get_type_for_mime (const gchar *mime)
{
guint16 typeid;
typeid = gst_type_find_by_mime (mime);
if (typeid == 0) {
GstTypeDefinition definition;
GstTypeFactory *factory;
definition.name = "capstype";
definition.mime = g_strdup (mime);
definition.exts = NULL;
definition.typefindfunc = NULL;
factory = gst_typefactory_new (&definition);
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
* @props: the properties to add to this capability
*
* Create a new capability with the given mime typei and properties.
*
* Returns: a new capability
*/
GstCaps*
gst_caps_new (const gchar *name, const gchar *mime, GstProps *props)
{
g_return_val_if_fail (mime != NULL, NULL);
return gst_caps_new_id (name, get_type_for_mime (mime), props);
}
/**
* gst_caps_new_id:
* @name: the name of this capability
* @id: the id of the mime type
* @props: the properties to add to this capability
*
* Create a new capability with the given mime typeid and properties.
*
* Returns: a new capability
*/
GstCaps*
gst_caps_new_id (const gchar *name, const guint16 id, GstProps *props)
{
GstCaps *caps;
g_mutex_lock (_gst_caps_chunk_lock);
caps = g_mem_chunk_alloc (_gst_caps_chunk);
g_mutex_unlock (_gst_caps_chunk_lock);
caps->name = g_strdup (name);
caps->id = id;
caps->properties = props;
caps->next = NULL;
caps->refcount = 1;
caps->lock = g_mutex_new ();
if (props)
caps->fixed = props->fixed;
else
caps->fixed = TRUE;
return caps;
}
/**
* gst_caps_destroy:
* @caps: the caps to destroy
*
* Frees the memory used by this caps structure and all
* the chained caps and properties.
*/
void
gst_caps_destroy (GstCaps *caps)
{
GstCaps *next;
if (caps == NULL)
return;
GST_CAPS_LOCK (caps);
next = caps->next;
GST_CAPS_UNLOCK (caps);
g_mutex_free (caps->lock);
gst_props_unref (caps->properties);
g_free (caps->name);
g_mutex_lock (_gst_caps_chunk_lock);
g_mem_chunk_free (_gst_caps_chunk, caps);
g_mutex_unlock (_gst_caps_chunk_lock);
if (next)
gst_caps_unref (next);
}
void
gst_caps_debug (GstCaps *caps)
{
GST_DEBUG_ENTER ("caps debug");
while (caps) {
GST_DEBUG (GST_CAT_CAPS, "caps: %p %s %s\n", caps, caps->name, gst_caps_get_mime (caps));
if (caps->properties) {
gst_props_debug (caps->properties);
}
else {
GST_DEBUG (GST_CAT_CAPS, "no properties\n");
}
caps = caps->next;
}
GST_DEBUG_LEAVE ("caps debug");
}
/**
* gst_caps_unref:
* @caps: the caps to unref
*
* Decrease the refcount of this caps structure,
* destroying it when the refcount is 0
*
* Returns: caps or NULL if the refcount reached 0
*/
GstCaps*
gst_caps_unref (GstCaps *caps)
{
gboolean zero;
GstCaps **next;
if (caps == NULL)
return NULL;
g_return_val_if_fail (caps->refcount > 0, NULL);
GST_CAPS_LOCK (caps);
caps->refcount--;
zero = (caps->refcount == 0);
next = &caps->next;
GST_CAPS_UNLOCK (caps);
if (*next)
*next = gst_caps_unref (*next);
if (zero) {
gst_caps_destroy (caps);
caps = NULL;
}
return caps;
}
/**
* gst_caps_ref:
* @caps: the caps to ref
*
* Increase the refcount of this caps structure
*
* Returns: the caps with the refcount incremented
*/
GstCaps*
gst_caps_ref (GstCaps *caps)
{
g_return_val_if_fail (caps != NULL, NULL);
GST_CAPS_LOCK (caps);
caps->refcount++;
GST_CAPS_UNLOCK (caps);
return caps;
}
/**
* gst_caps_copy:
* @caps: the caps to copy
*
* Copies the caps.
*
* Returns: a copy of the GstCaps structure.
*/
GstCaps*
gst_caps_copy (GstCaps *caps)
{
GstCaps *new = NULL, *walk = NULL;
while (caps) {
GstCaps *newcaps;
newcaps = gst_caps_new_id (
caps->name,
caps->id,
gst_props_copy (caps->properties));
if (new == NULL) {
new = walk = newcaps;
}
else {
walk = walk->next = newcaps;
}
caps = caps->next;
}
return new;
}
/**
* gst_caps_copy_on_write:
* @caps: the caps to copy
*
* Copies the caps if the refcount is greater than 1
*
* Returns: a pointer to a GstCaps strcuture that can
* be safely written to
*/
GstCaps*
gst_caps_copy_on_write (GstCaps *caps)
{
GstCaps *new = caps;
gboolean needcopy;
g_return_val_if_fail (caps != NULL, NULL);
GST_CAPS_LOCK (caps);
needcopy = (caps->refcount > 1);
GST_CAPS_UNLOCK (caps);
if (needcopy) {
new = gst_caps_copy (caps);
gst_caps_unref (caps);
}
return new;
}
/**
* 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
* @type_id: 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_chain:
* @caps: a capabilty
* @...: more capabilities
*
* chains the given capabilities
*
* Returns: the new capability
*/
GstCaps*
gst_caps_chain (GstCaps *caps, ...)
{
GstCaps *orig = caps;
va_list var_args;
va_start (var_args, caps);
while (caps) {
GstCaps *toadd;
toadd = va_arg (var_args, GstCaps*);
gst_caps_append (caps, toadd);
caps = toadd;
}
va_end (var_args);
return orig;
}
/**
* 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;
g_return_val_if_fail (caps != capstoadd, 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;
g_return_val_if_fail (caps != capstoadd, caps);
while (capstoadd->next) {
capstoadd = capstoadd->next;
}
capstoadd->next = caps;
return orig;
}
/**
* gst_caps_get_by_name:
* @caps: a capabilty
* @name: the name of the capability to get
*
* Get the capability with the given name from this
* chain of capabilities.
*
* Returns: the first capability in the chain with the
* given name
*/
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 (GST_CAT_CAPS,"mime types differ (%s to %s)\n",
gst_type_find_by_id (fromcaps->id)->mime,
gst_type_find_by_id (tocaps->id)->mime);
return FALSE;
}
if (tocaps->properties) {
if (fromcaps->properties) {
return gst_props_check_compatibility (fromcaps->properties, tocaps->properties);
}
else {
GST_DEBUG (GST_CAT_CAPS,"no source caps\n");
return FALSE;
}
}
else {
/* assume it accepts everything */
GST_DEBUG (GST_CAT_CAPS,"no caps\n");
return TRUE;
}
}
/**
* gst_caps_check_compatibility:
* @fromcaps: a capabilty
* @tocaps: a capabilty
*
* Checks whether two capabilities are compatible.
*
* Returns: TRUE if compatible, FALSE otherwise
*/
gboolean
gst_caps_check_compatibility (GstCaps *fromcaps, GstCaps *tocaps)
{
if (fromcaps == NULL) {
if (tocaps == NULL) {
GST_DEBUG (GST_CAT_CAPS,"no caps\n");
return TRUE;
}
else {
GST_DEBUG (GST_CAT_CAPS,"no source but destination caps\n");
return FALSE;
}
}
else {
if (tocaps == NULL) {
GST_DEBUG (GST_CAT_CAPS,"source caps and no destination 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;
}
static GstCaps*
gst_caps_intersect_func (GstCaps *caps1, GstCaps *caps2)
{
GstCaps *result = NULL;
GstProps *props;
if (caps1->id != caps2->id) {
GST_DEBUG (GST_CAT_CAPS,"mime types differ (%s to %s)\n",
gst_type_find_by_id (caps1->id)->mime,
gst_type_find_by_id (caps2->id)->mime);
return NULL;
}
if (caps1->properties == NULL) {
return gst_caps_ref (caps2);
}
if (caps2->properties == NULL) {
return gst_caps_ref (caps1);
}
props = gst_props_intersect (caps1->properties, caps2->properties);
if (props) {
result = gst_caps_new_id ("intersect", caps1->id, props);
}
return result;
}
/**
* gst_caps_intersect:
* @caps1: a capabilty
* @caps2: a capabilty
*
* Make the intersection between two caps.
*
* Returns: The intersection of the two caps or NULL if the intersection
* is empty.
*/
GstCaps*
gst_caps_intersect (GstCaps *caps1, GstCaps *caps2)
{
GstCaps *result = NULL, *walk = NULL;
if (caps1 == NULL) {
GST_DEBUG (GST_CAT_CAPS, "first caps is NULL, return other caps\n");
return gst_caps_copy (caps2);
}
if (caps2 == NULL) {
GST_DEBUG (GST_CAT_CAPS, "second caps is NULL, return other caps\n");
return gst_caps_copy (caps1);
}
while (caps1) {
GstCaps *othercaps = caps2;
while (othercaps) {
GstCaps *intersection = gst_caps_intersect_func (caps1, othercaps);
if (intersection) {
if (!result) {
walk = result = intersection;
}
else {
walk = walk->next = intersection;
}
}
othercaps = othercaps->next;
}
caps1 = caps1->next;
}
return result;
}
GstCaps*
gst_caps_normalize (GstCaps *caps)
{
GstCaps *result = NULL, *walk = caps;
if (caps == NULL)
return caps;
while (caps) {
GList *proplist;
proplist = gst_props_normalize (caps->properties);
if (proplist && g_list_next (proplist) == NULL) {
if (result == NULL)
walk = result = caps;
else {
walk = walk->next = caps;
}
goto next;
}
while (proplist) {
GstProps *props = (GstProps *) proplist->data;
GstCaps *newcaps = gst_caps_new_id (caps->name, caps->id, props);
if (result == NULL)
walk = result = newcaps;
else {
walk = walk->next = newcaps;
}
proplist = g_list_next (proplist);
}
next:
caps = caps->next;
}
return result;
}
#ifndef GST_DISABLE_LOADSAVE_REGISTRY
/**
* 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;
gchar *content;
g_mutex_lock (_gst_caps_chunk_lock);
caps = g_mem_chunk_alloc0 (_gst_caps_chunk);
g_mutex_unlock (_gst_caps_chunk_lock);
caps->refcount = 1;
caps->lock = g_mutex_new ();
caps->next = NULL;
caps->fixed = TRUE;
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;
}
#endif /* GST_DISABLE_LOADSAVE_REGISTRY */