gstreamer/gst/gstelement.c
Wim Taymans 3b805b9209 Docs updates: remove sink, src, filter, connection added gstinfo to docs.
Original commit message from CVS:
Docs updates: remove sink, src, filter, connection
added gstinfo to docs.
Updated some core files for the docs
gsttypefind did not include gst_private
Added CFlags to Makefile.am in gst/elements
2000-12-30 16:13:17 +00:00

856 lines
23 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstelement.c: The base element, all elements derive from this
*
* 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 "gstelement.h"
#include "gstextratypes.h"
/* Element signals and args */
enum {
STATE_CHANGE,
NEW_PAD,
NEW_GHOST_PAD,
ERROR,
EOS,
LAST_SIGNAL
};
enum {
ARG_0,
/* FILL ME */
};
static void gst_element_class_init (GstElementClass *klass);
static void gst_element_init (GstElement *element);
static void gst_element_real_destroy (GtkObject *object);
static GstElementStateReturn gst_element_change_state(GstElement *element);
static GstObjectClass *parent_class = NULL;
static guint gst_element_signals[LAST_SIGNAL] = { 0 };
GtkType gst_element_get_type(void) {
static GtkType element_type = 0;
if (!element_type) {
static const GtkTypeInfo element_info = {
"GstElement",
sizeof(GstElement),
sizeof(GstElementClass),
(GtkClassInitFunc)gst_element_class_init,
(GtkObjectInitFunc)gst_element_init,
(GtkArgSetFunc)NULL,
(GtkArgGetFunc)NULL,
(GtkClassInitFunc)NULL,
};
element_type = gtk_type_unique(GST_TYPE_OBJECT,&element_info);
}
return element_type;
}
static void
gst_element_class_init (GstElementClass *klass)
{
GtkObjectClass *gtkobject_class;
gtkobject_class = (GtkObjectClass*)klass;
parent_class = gtk_type_class(GST_TYPE_OBJECT);
gst_element_signals[STATE_CHANGE] =
gtk_signal_new ("state_change", GTK_RUN_LAST, gtkobject_class->type,
GTK_SIGNAL_OFFSET (GstElementClass, state_change),
gtk_marshal_NONE__INT, GTK_TYPE_NONE, 1,
GTK_TYPE_INT);
gst_element_signals[NEW_PAD] =
gtk_signal_new ("new_pad", GTK_RUN_LAST, gtkobject_class->type,
GTK_SIGNAL_OFFSET (GstElementClass, new_pad),
gtk_marshal_NONE__POINTER, GTK_TYPE_NONE, 1,
GST_TYPE_PAD);
gst_element_signals[NEW_GHOST_PAD] =
gtk_signal_new ("new_ghost_pad", GTK_RUN_LAST, gtkobject_class->type,
GTK_SIGNAL_OFFSET (GstElementClass, new_ghost_pad),
gtk_marshal_NONE__POINTER, GTK_TYPE_NONE, 1,
GST_TYPE_PAD);
gst_element_signals[ERROR] =
gtk_signal_new ("error", GTK_RUN_LAST, gtkobject_class->type,
GTK_SIGNAL_OFFSET (GstElementClass, error),
gtk_marshal_NONE__STRING, GTK_TYPE_NONE,1,
GTK_TYPE_STRING);
gst_element_signals[EOS] =
gtk_signal_new ("eos", GTK_RUN_LAST, gtkobject_class->type,
GTK_SIGNAL_OFFSET (GstElementClass,eos),
gtk_marshal_NONE__NONE, GTK_TYPE_NONE, 0);
gtk_object_class_add_signals (gtkobject_class, gst_element_signals, LAST_SIGNAL);
klass->change_state = gst_element_change_state;
klass->elementfactory = NULL;
gtkobject_class->destroy = gst_element_real_destroy;
}
static void
gst_element_init (GstElement *element)
{
element->current_state = GST_STATE_NULL;
element->pending_state = -1;
element->numpads = 0;
element->numsrcpads = 0;
element->numsinkpads = 0;
element->pads = NULL;
element->loopfunc = NULL;
element->threadstate = NULL;
}
/**
* gst_element_new:
*
* Create a new element. Should never be used, as it does no good.
*
* Returns: new element
*/
GstElement*
gst_element_new(void)
{
return GST_ELEMENT (gtk_type_new (GST_TYPE_ELEMENT));
}
/**
* gst_element_add_pad:
* @element: element to add pad to
* @pad: pad to add
*
* Add a pad (connection point) to the element, setting the parent of the
* pad to the element (and thus adding a reference).
*/
void
gst_element_add_pad (GstElement *element, GstPad *pad)
{
g_return_if_fail (element != NULL);
g_return_if_fail (GST_IS_ELEMENT (element));
g_return_if_fail (pad != NULL);
g_return_if_fail (GST_IS_PAD (pad));
/* set the pad's parent */
DEBUG("setting parent of pad '%s'(%p) to '%s'(%p)\n",
gst_pad_get_name(pad),pad,gst_element_get_name(element),element);
gst_pad_set_parent (pad,GST_OBJECT (element));
/* add it to the list */
element->pads = g_list_append (element->pads, pad);
element->numpads++;
if (gst_pad_get_direction (pad) == GST_PAD_SRC)
element->numsrcpads++;
else
element->numsinkpads++;
/* emit the NEW_PAD signal */
gtk_signal_emit (GTK_OBJECT (element), gst_element_signals[NEW_PAD], pad);
}
/**
* gst_element_add_ghost_pad:
* @element: element to add ghost pad to
* @pad: ghost pad to add
*
* Add a ghost pad to the element, setting the ghost parent of the pad to
* the element (and thus adding a reference).
*/
void
gst_element_add_ghost_pad (GstElement *element, GstPad *pad)
{
g_return_if_fail (element != NULL);
g_return_if_fail (GST_IS_ELEMENT (element));
g_return_if_fail (pad != NULL);
g_return_if_fail (GST_IS_PAD (pad));
/* set the pad's parent */
gst_pad_add_ghost_parent (pad,GST_OBJECT (element));
/* add it to the list */
element->pads = g_list_append (element->pads, pad);
element->numpads++;
/* emit the NEW_PAD signal */
gtk_signal_emit (GTK_OBJECT (element), gst_element_signals[NEW_GHOST_PAD], pad);
}
/**
* gst_element_get_pad:
* @element: element to find pad of
* @name: name of pad to retrieve
*
* Retrieve a pad from the element by name.
*
* Returns: requested pad if found, otherwise NULL.
*/
GstPad*
gst_element_get_pad (GstElement *element, gchar *name)
{
GList *walk;
g_return_val_if_fail (element != NULL, NULL);
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
if (name == NULL)
return NULL;
if (!element->numpads)
return NULL;
/* look through the list, matching by name */
walk = element->pads;
while (walk) {
if (!strcmp ((GST_PAD(walk->data))->name, name))
return GST_PAD(walk->data);
walk = g_list_next (walk);
}
return NULL;
}
/**
* gst_element_get_pad_list:
* @element: element to get pads of
*
* Retrieve a list of the pads associated with the element.
*
* Returns: GList of pads
*/
GList*
gst_element_get_pad_list (GstElement *element)
{
g_return_val_if_fail (element != NULL, NULL);
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
/* return the list of pads */
return element->pads;
}
/**
* gst_element_get_padtemplate_list:
* @element: element to get padtemplates of
*
* Retrieve a list of the padtemplates associated with the element.
*
* Returns: GList of padtemplates
*/
GList*
gst_element_get_padtemplate_list (GstElement *element)
{
GstElementClass *oclass;
g_return_val_if_fail (element != NULL, NULL);
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
oclass = GST_ELEMENT_CLASS (GTK_OBJECT (element)->klass);
if (oclass->elementfactory == NULL) return NULL;
/* return the list of pads */
return oclass->elementfactory->padtemplates;
}
/**
* gst_element_connect:
* @src: element containing source pad
* @srcpadname: name of pad in source element
* @dest: element containing destination pad
* @destpadname: name of pad in destination element
*
* Connect the two named pads of the source and destination elements.
* Side effect is that if one of the pads has no parent, it becomes a
* child of the parent of the other element. If they have different
* parents, the connection fails.
*/
void
gst_element_connect (GstElement *src, gchar *srcpadname,
GstElement *dest, gchar *destpadname)
{
GstPad *srcpad,*destpad;
GstObject *srcparent,*destparent;
g_return_if_fail (src != NULL);
g_return_if_fail (GST_IS_ELEMENT(src));
g_return_if_fail (srcpadname != NULL);
g_return_if_fail (dest != NULL);
g_return_if_fail (GST_IS_ELEMENT(dest));
g_return_if_fail (destpadname != NULL);
/* obtain the pads requested */
srcpad = gst_element_get_pad (src, srcpadname);
if (srcpad == NULL) {
ERROR(src,"source element has no pad \"%s\"",srcpadname);
return;
}
destpad = gst_element_get_pad (dest, destpadname);
if (srcpad == NULL) {
ERROR(dest,"destination element has no pad \"%s\"",destpadname);
return;
}
/* find the parent elements of each element */
srcparent = gst_object_get_parent (GST_OBJECT (src));
destparent = gst_object_get_parent (GST_OBJECT (dest));
/* have to make sure that they have the same parents... */
if (srcparent != destparent) {
ERROR_OBJECT(srcparent,destparent,"%s and %s have different parents",
gst_element_get_name(src),gst_element_get_name(dest));
return;
}
/* we're satisified they can be connected, let's do it */
gst_pad_connect(srcpad,destpad);
}
/**
* gst_element_error:
* @element: Element with the error
* @error: String describing the error
*
* This function is used internally by elements to signal an error
* condition. It results in the "error" signal.
*/
void
gst_element_error (GstElement *element, gchar *error)
{
g_error("GstElement: error in element '%s': %s\n", element->name, error);
/* FIXME: this is not finished!!! */
gtk_signal_emit (GTK_OBJECT (element), gst_element_signals[ERROR], error);
}
/**
* gst_element_set_state:
* @element: element to change state of
* @state: new element state
*
* Sets the state of the element. This function will only set
* the elements pending state.
*
* Returns: whether or not the state was successfully set.
*/
gint
gst_element_set_state (GstElement *element, GstElementState state)
{
GstElementClass *oclass;
GstElementState curpending;
GstElementStateReturn return_val = GST_STATE_SUCCESS;
// g_print("gst_element_set_state(\"%s\",%08lx)\n",
// element->name,state);
g_return_val_if_fail (element != NULL, GST_STATE_FAILURE);
g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_FAILURE);
/* start with the current state */
curpending = GST_STATE(element);
/* loop until the final requested state is set */
while (GST_STATE(element) != state) {
/* move the curpending state in the correct direction */
if (curpending < state) curpending++;
else curpending--;
/* set the pending state variable */
// FIXME: should probably check to see that we don't already have one
GST_STATE_PENDING (element) = curpending;
/* call the state change function so it can set the state */
oclass = GST_ELEMENT_CLASS (GTK_OBJECT (element)->klass);
if (oclass->change_state)
return_val = (oclass->change_state)(element);
/* if that outright didn't work, we need to bail right away */
/* NOTE: this will bail on ASYNC as well! */
if (return_val == GST_STATE_FAILURE) {
// DEBUG("have async return from '%s'\n",gst_element_get_name(element));
return return_val;
}
}
/* this is redundant, really, it will always return SUCCESS */
return return_val;
}
/**
* gst_element_get_factory:
* @element: element to request the factory
*
* Retrieves the factory that was used to create this element
*
* Returns: the factory used for creating this element
*/
GstElementFactory*
gst_element_get_factory (GstElement *element)
{
GstElementClass *oclass;
g_return_val_if_fail (element != NULL, NULL);
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
oclass = GST_ELEMENT_CLASS (GTK_OBJECT (element)->klass);
return oclass->elementfactory;
}
/**
* gst_element_change_state:
* @element: element to change state of
*
* Changes the state of the element, but more importantly fires off a signal
* indicating the new state.
* The element will have no pending states anymore.
*
* Returns: whether or not the state change was successfully set.
*/
GstElementStateReturn
gst_element_change_state (GstElement *element)
{
g_return_val_if_fail (element != NULL, GST_STATE_FAILURE);
g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_FAILURE);
// g_print("gst_element_change_state(\"%s\",%d)\n",
// element->name,state);
GST_STATE (element) = GST_STATE_PENDING (element);
GST_STATE_PENDING (element) = GST_STATE_NONE_PENDING;
gtk_signal_emit (GTK_OBJECT (element), gst_element_signals[STATE_CHANGE],
GST_STATE (element));
return TRUE;
}
/**
* gst_element_set_name:
* @element: GstElement to set name of
* @name: new name of element
*
* Set the name of the element, getting rid of the old name if there was
* one.
*/
void
gst_element_set_name (GstElement *element, gchar *name)
{
g_return_if_fail (element != NULL);
g_return_if_fail (GST_IS_ELEMENT (element));
g_return_if_fail (name != NULL);
if (element->name != NULL)
g_free(element->name);
element->name = g_strdup (name);
}
/**
* gst_element_get_name:
* @element: GstElement to set name of
*
* Get the name of the element.
*
* Returns: name of the element
*/
const gchar*
gst_element_get_name (GstElement *element)
{
g_return_val_if_fail (element != NULL, NULL);
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
return element->name;
}
static void
gst_element_real_destroy (GtkObject *object)
{
GstElement *element = GST_ELEMENT (object);
GList *pads;
GstPad *pad;
// g_print("in gst_element_real_destroy()\n");
if (element->name)
g_free (element->name);
pads = element->pads;
while (pads) {
pad = GST_PAD (pads->data);
gst_pad_destroy (pad);
pads = g_list_next (pads);
}
g_list_free (element->pads);
}
/*
static gchar *_gst_element_type_names[] = {
"invalid",
"none",
"char",
"uchar",
"bool",
"int",
"uint",
"long",
"ulong",
"float",
"double",
"string",
};
*/
/**
* gst_element_save_thyself:
* @element: GstElement to save
* @parent: the xml parent node
*
* saves the element
*
* Returns: the new xml node
*/
xmlNodePtr
gst_element_save_thyself (GstElement *element,
xmlNodePtr parent)
{
xmlNodePtr self;
GList *pads;
GstPad *pad;
GstElementClass *oclass;
GstElementFactory *factory;
GtkType type;
oclass = GST_ELEMENT_CLASS (GTK_OBJECT (element)->klass);
self = xmlNewChild (parent, NULL, "element", NULL);
xmlNewChild(self, NULL, "name", element->name);
if (oclass->elementfactory != NULL) {
factory = (GstElementFactory *)oclass->elementfactory;
xmlNewChild (self, NULL, "type", factory->name);
xmlNewChild (self, NULL, "version", factory->details->version);
}
// output all args to the element
type = GTK_OBJECT_TYPE (element);
while (type != GTK_TYPE_INVALID) {
GtkArg *args;
guint32 *flags;
guint num_args,i;
args = gtk_object_query_args (type, &flags, &num_args);
for (i=0; i<num_args; i++) {
if ((args[i].type > GTK_TYPE_NONE) &&
//(args[i].type <= GTK_TYPE_STRING) &&
(flags[i] & GTK_ARG_READABLE)) {
xmlNodePtr arg;
gtk_object_getv (GTK_OBJECT (element), 1, &args[i]);
arg = xmlNewChild (self, NULL, "arg", NULL);
xmlNewChild (arg, NULL, "name", args[i].name);
switch (args[i].type) {
case GTK_TYPE_CHAR:
xmlNewChild (arg, NULL, "value",
g_strdup_printf ("%c", GTK_VALUE_CHAR (args[i])));
break;
case GTK_TYPE_UCHAR:
xmlNewChild (arg, NULL, "value",
g_strdup_printf ("%d", GTK_VALUE_UCHAR (args[i])));
break;
case GTK_TYPE_BOOL:
xmlNewChild (arg, NULL, "value",
GTK_VALUE_BOOL (args[i]) ? "true" : "false");
break;
case GTK_TYPE_INT:
xmlNewChild (arg, NULL, "value",
g_strdup_printf ("%d", GTK_VALUE_INT (args[i])));
break;
case GTK_TYPE_LONG:
xmlNewChild (arg, NULL, "value",
g_strdup_printf ("%ld", GTK_VALUE_LONG (args[i])));
break;
case GTK_TYPE_ULONG:
xmlNewChild (arg, NULL, "value",
g_strdup_printf ("%lu", GTK_VALUE_ULONG (args[i])));
break;
case GTK_TYPE_FLOAT:
xmlNewChild (arg, NULL, "value",
g_strdup_printf ("%f", GTK_VALUE_FLOAT (args[i])));
break;
case GTK_TYPE_DOUBLE:
xmlNewChild (arg, NULL, "value",
g_strdup_printf ("%g", GTK_VALUE_DOUBLE (args[i])));
break;
case GTK_TYPE_STRING:
xmlNewChild (arg, NULL, "value", GTK_VALUE_STRING (args[i]));
break;
default:
if (args[i].type == GST_TYPE_FILENAME) {
xmlNewChild (arg, NULL, "value", GTK_VALUE_STRING (args[i]));
}
break;
}
}
}
type = gtk_type_parent (type);
}
pads = element->pads;
while (pads) {
xmlNodePtr padtag = xmlNewChild (self, NULL, "pad", NULL);
pad = GST_PAD (pads->data);
// figure out if it's a direct pad or a ghostpad
if (GST_ELEMENT (pad->parent) == element)
gst_pad_save_thyself (pad, padtag);
pads = g_list_next (pads);
}
if (oclass->save_thyself)
(oclass->save_thyself)(element, self);
return self;
}
/**
* gst_element_load_thyself:
* @parent: the xml parent node
* @elements: a hashtable to store the elements in. This is used
* to resolve inter element dependecies during the loading.
*
* load the element based on the XML description
*
* Returns: the new element
*/
GstElement*
gst_element_load_thyself (xmlNodePtr parent,
GHashTable *elements)
{
xmlNodePtr children = parent->childs;
GstElement *element;
GstElementClass *oclass;
guchar *name = NULL;
guchar *value = NULL;
guchar *type = NULL;
// first get the needed tags to construct the element
while (children) {
if (!strcmp (children->name, "name")) {
name = g_strdup (xmlNodeGetContent (children));
} else if (!strcmp (children->name, "type")) {
type = g_strdup (xmlNodeGetContent (children));
}
children = children->next;
}
g_return_val_if_fail (name != NULL, NULL);
g_return_val_if_fail (type != NULL, NULL);
INFO(GST_INFO_XML,"loading \"%s\" of type \"%s\"\n", name, type);
element = gst_elementfactory_make (type, name);
g_return_val_if_fail (element != NULL, NULL);
g_hash_table_insert (elements, g_strdup (gst_element_get_name (element)), element);
// we have the element now, set the arguments
children = parent->childs;
while (children) {
if (!strcmp (children->name, "arg")) {
xmlNodePtr child = children->childs;
while (child) {
if (!strcmp (child->name, "name")) {
name = g_strdup (xmlNodeGetContent (child));
}
else if (!strcmp (child->name, "value")) {
value = g_strdup (xmlNodeGetContent (child));
}
child = child->next;
}
if (name && value) {
GtkType type = GTK_OBJECT_TYPE (element);
GtkArgInfo *info;
gchar *result;
result = gtk_object_arg_get_info (type, name, &info);
if (result) {
g_print("gstelement: %s\n", result);
}
else if (info->arg_flags & GTK_ARG_WRITABLE) {
switch (info->type) {
case GTK_TYPE_STRING:
gtk_object_set (GTK_OBJECT (element), name, value, NULL);
break;
case GTK_TYPE_INT: {
gint i;
sscanf (value, "%d", &i);
gtk_object_set (GTK_OBJECT (element), name, i, NULL);
break;
}
case GTK_TYPE_LONG: {
glong i;
sscanf (value, "%ld", &i);
gtk_object_set (GTK_OBJECT (element), name, i, NULL);
break;
}
case GTK_TYPE_ULONG: {
gulong i;
sscanf (value, "%lu", &i);
gtk_object_set (GTK_OBJECT (element), name, i, NULL);
break;
}
case GTK_TYPE_BOOL: {
gboolean i = FALSE;
if (!strcmp ("true", value)) i = TRUE;
gtk_object_set (GTK_OBJECT (element), name, i, NULL);
break;
}
case GTK_TYPE_CHAR: {
gchar i;
sscanf (value, "%c", &i);
gtk_object_set (GTK_OBJECT (element), name, i, NULL);
break;
}
case GTK_TYPE_UCHAR: {
guchar i;
sscanf (value, "%c", &i);
gtk_object_set (GTK_OBJECT (element), name, i, NULL);
break;
}
case GTK_TYPE_FLOAT: {
gfloat i;
sscanf (value, "%f", &i);
gtk_object_set (GTK_OBJECT (element), name, i, NULL);
break;
}
case GTK_TYPE_DOUBLE: {
gdouble i;
sscanf (value, "%g", (float *)&i);
gtk_object_set (GTK_OBJECT (element), name, i, NULL);
break;
}
default:
if (info->type == GST_TYPE_FILENAME) {
gtk_object_set (GTK_OBJECT (element), name, value, NULL);
}
break;
}
}
}
}
children = children->next;
}
// we have the element now, set the pads
children = parent->childs;
while (children) {
if (!strcmp (children->name, "pad")) {
gst_pad_load_and_connect (children, GST_OBJECT(element), elements);
}
children = children->next;
}
oclass = GST_ELEMENT_CLASS (GTK_OBJECT (element)->klass);
if (oclass->restore_thyself)
(oclass->restore_thyself) (element, parent, elements);
return element;
}
/**
* gst_element_set_manager:
* @element: Element to set manager of.
* @manager: Element to be the manager.
*
* Sets the manager of the element. For internal use only, unless you're
* writing a new bin subclass.
*/
void
gst_element_set_manager (GstElement *element,
GstElement *manager)
{
element->manager = manager;
}
/**
* gst_element_get_manager:
* @element: Element to get manager of.
*
* Returns the manager of the element.
*
* Returns: Element's manager
*/
GstElement*
gst_element_get_manager (GstElement *element)
{
return element->manager;
}
/**
* gst_element_set_loop_function:
* @element: Element to set loop function of.
* @loop: Pointer to loop function.
*
* This sets the loop function for the element. The function pointed to
* can deviate from the GstElementLoopFunction definition in type of
* pointer only.
*
* NOTE: in order for this to take effect, the current loop function *must*
* exit. Assuming the loop function itself is the only one who will cause
* a new loopfunc to be assigned, this should be no problem.
*/
void
gst_element_set_loop_function(GstElement *element,
GstElementLoopFunction loop)
{
/* set the loop function */
element->loopfunc = loop;
/* set the NEW_LOOPFUNC flag so everyone knows to go try again */
GST_FLAG_SET(element,GST_ELEMENT_NEW_LOOPFUNC);
}
/**
* gst_element_signal_eos:
* @element: element to trigger the eos signal of
*
* singals the eos signal to indicate that the end of the stream
* is reached.
*/
void
gst_element_signal_eos (GstElement *element)
{
g_return_if_fail (element != NULL);
g_return_if_fail (GST_IS_ELEMENT (element));
gtk_signal_emit (GTK_OBJECT (element), gst_element_signals[EOS]);
}