gstreamer/gst/autoplug/gstspider.c

713 lines
23 KiB
C
Raw Normal View History

/* GStreamer
* Copyright (C) 2002 Erik Walthinsen <omega@cse.ogi.edu>
* 2002 Wim Taymans <wtay@chello.be>
*
* gstspider.c: element to automatically connect sinks and sources
*
* 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.
*/
/*
* TODO:
* - handle automatic removal of unneeded elements
* - make the spider handle and send events (esp. new media)
* - decide if we plug pads or elements, currently it's a mess
* - allow disconnecting
* - implement proper saving/loading from xml
* - implement a way to allow merging/splitting (aka tee)
* - find ways to define which elements to use when plugging
* - remove pads
* - improve typefinding
* - react to errors inside the pipeline
* - implement more properties, change the current
* - emit signals (most important: "NOT PLUGGABLE")
* - implement something for reporting the state of the spider
* to allow easier debugging.
* (could be useful for bins in general)
* - fix bugs
* ...
*/
#include "gstspider.h"
#include "gstspideridentity.h"
#include "gstsearchfuncs.h"
/* signals and args */
enum {
/* FILL ME */
LAST_SIGNAL
};
enum {
ARG_0,
ARG_FACTORIES,
/* FILL ME TOO */
};
/* generic templates */
GST_PAD_TEMPLATE_FACTORY (spider_src_factory,
"src_%d",
GST_PAD_SRC,
GST_PAD_REQUEST,
NULL /* no caps */
);
GST_PAD_TEMPLATE_FACTORY (spider_sink_factory,
"sink_%d",
GST_PAD_SINK,
GST_PAD_REQUEST,
NULL /* no caps */
);
/* standard GObject stuff */
static void gst_spider_class_init (GstSpiderClass *klass);
static void gst_spider_init (GstSpider *spider);
static void gst_spider_dispose (GObject *object);
/* element class functions */
static GstPad* gst_spider_request_new_pad (GstElement *element, GstPadTemplate *templ, const gchar *name);
static void gst_spider_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec);
static void gst_spider_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec);
/* connection functions */
static GstSpiderConnection * gst_spider_connection_new (GstSpiderIdentity *sink, GstSpiderIdentity *src);
static void gst_spider_connection_destroy (GstSpiderConnection *conn);
static void gst_spider_connection_reset (GstSpiderConnection *conn, GstElement *to);
static void gst_spider_connection_add (GstSpiderConnection *conn, GstElement *element);
static GstSpiderConnection * gst_spider_connection_find (GstSpiderIdentity *sink, GstSpiderIdentity *src);
static GstSpiderConnection * gst_spider_connection_get (GstSpiderIdentity *sink, GstSpiderIdentity *src);
/* autoplugging functions */
static GstElement * gst_spider_find_element_to_plug (GstElement *src, GstElementFactory *fac, GstPadDirection dir);
static GstPadConnectReturn gst_spider_plug (GstSpiderConnection *conn);
static GstPadConnectReturn gst_spider_plug_from_srcpad (GstSpiderConnection *conn, GstPad *srcpad);
/*static GstPadConnectReturn gst_spider_plug_peers (GstSpider *spider, GstPad *srcpad, GstPad *sinkpad); */
static GstPadConnectReturn gst_spider_create_and_plug (GstSpiderConnection *conn, GList *plugpath);
/* random functions */
static gchar * gst_spider_unused_elementname (GstBin *bin, const gchar *startwith);
/* debugging stuff
static void print_spider_contents (GstSpider *spider);
static void print_spider_connection (GstSpiderConnection *conn); */
/* === variables === */
static GstElementClass * parent_class = NULL;
/* no signals yet
static guint gst_spider_signals[LAST_SIGNAL] = { 0 };*/
/* let gstreamer know that we have some request pads available */
GST_PAD_TEMPLATE_FACTORY (gst_spider_sink_template_factory,
"sink%d",
GST_PAD_SINK,
GST_PAD_REQUEST,
NULL
);
GST_PAD_TEMPLATE_FACTORY (gst_spider_src_template_factory,
"src%d",
GST_PAD_SRC,
GST_PAD_REQUEST,
NULL
);
/* GObject and GStreamer init functions */
GType
gst_spider_get_type(void)
{
static GType spider_type = 0;
if (!spider_type) {
static const GTypeInfo spider_info = {
sizeof(GstSpiderClass),
NULL,
NULL,
(GClassInitFunc) gst_spider_class_init,
NULL,
NULL,
sizeof(GstSpider),
0,
(GInstanceInitFunc)gst_spider_init,
};
spider_type = g_type_register_static (GST_TYPE_BIN, "GstSpider", &spider_info, 0);
}
return spider_type;
}
static void
gst_spider_class_init (GstSpiderClass *klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
gobject_class = (GObjectClass*) klass;
gstelement_class = (GstElementClass*) klass;
parent_class = g_type_class_ref(GST_TYPE_BIN);
/* properties */
g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_FACTORIES,
g_param_spec_pointer ("factories", "allowed factories", "allowed factories for autoplugging", G_PARAM_READWRITE));
gobject_class->set_property = gst_spider_set_property;
gobject_class->get_property = gst_spider_get_property;
gobject_class->dispose = gst_spider_dispose;
gst_element_class_add_pad_template (gstelement_class, gst_spider_src_template_factory());
gst_element_class_add_pad_template (gstelement_class, gst_spider_sink_template_factory());
gstelement_class->request_new_pad = GST_DEBUG_FUNCPTR(gst_spider_request_new_pad);
}
static void
gst_spider_init (GstSpider *spider)
{
/* use only elements which have sources and sinks and where the sinks have caps */
/* FIXME: How do we handle factories that are added after the spider was constructed? */
spider->factories = gst_autoplug_factories_filters_with_sink_caps ((GList *)
gst_registry_pool_feature_list (GST_TYPE_ELEMENT_FACTORY));
spider->connections = NULL;
}
static void
gst_spider_dispose (GObject *object)
{
GstSpider *spider;
spider = GST_SPIDER (object);
g_list_free (spider->factories);
((GObjectClass *) parent_class)->dispose (object);
}
static GstPad *
gst_spider_request_new_pad (GstElement *element, GstPadTemplate *templ, const gchar *name)
{
GstPad *returnpad;
gchar *padname;
GstSpiderIdentity *identity;
GstSpider *spider;
g_return_val_if_fail (templ != NULL, NULL);
g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
spider = GST_SPIDER (element);
/* create an identity object, so we have a pad */
switch ( GST_PAD_TEMPLATE_DIRECTION (templ))
{
case GST_PAD_SRC:
padname = gst_spider_unused_elementname ((GstBin *)spider, "src_");
identity = gst_spider_identity_new_src (padname);
returnpad = identity->src;
break;
case GST_PAD_SINK:
padname = gst_spider_unused_elementname ((GstBin *)spider, "sink_");
identity = gst_spider_identity_new_sink (padname);
returnpad = identity->sink;
break;
case GST_PAD_UNKNOWN:
default:
g_warning("Spider: you must request a source or sink pad.");
return NULL;
}
/* FIXME: use the requested name for the pad */
gst_object_ref (GST_OBJECT (templ));
GST_PAD_PAD_TEMPLATE (returnpad) = templ;
gst_bin_add (GST_BIN (element), GST_ELEMENT (identity));
returnpad = gst_element_add_ghost_pad (element, returnpad, padname);
GST_DEBUG (GST_CAT_ELEMENT_PADS, "successuflly created requested pad %s:%s", GST_DEBUG_PAD_NAME (returnpad));
return returnpad;
}
static void
gst_spider_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
{
GstSpider *spider;
GList *list;
/* it's not null if we got it, but it might not be ours */
g_return_if_fail (GST_IS_SPIDER (object));
spider = GST_SPIDER (object);
switch (prop_id) {
case ARG_FACTORIES:
list = (GList *) g_value_get_pointer (value);
while (list)
{
g_return_if_fail (list->data != NULL);
g_return_if_fail (GST_IS_ELEMENT_FACTORY (list->data));
list = g_list_next (list);
}
g_list_free (spider->factories);
spider->factories = (GList *) g_value_get_pointer (value);
break;
default:
break;
}
}
static void
gst_spider_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
{
GstSpider *spider;
/* it's not null if we got it, but it might not be ours */
spider = GST_SPIDER(object);
switch (prop_id) {
case ARG_FACTORIES:
g_value_set_pointer (value, spider->factories);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
/* get a name for an element that isn't used yet */
static gchar *
gst_spider_unused_elementname (GstBin *bin, const gchar *startwith)
{
gchar * name = g_strdup_printf ("%s%d", startwith, 0);
guint i;
for (i = 0; gst_bin_get_by_name (bin, name) != NULL; )
{
g_free (name);
name = g_strdup_printf ("%s%d", startwith, ++i);
}
return name;
}
static void
gst_spider_connect_sometimes (GstElement *src, GstPad *pad, GstSpiderConnection *conn)
{
gboolean restart = FALSE;
gulong signal_id = conn->signal_id;
GstPad *sinkpad = conn->src->sink;
GstSpider *spider = GST_SPIDER (GST_OBJECT_PARENT (conn->sink));
/* check if restarting is necessary */
if (gst_element_get_state ((GstElement *) spider) == GST_STATE_PLAYING)
{
restart = TRUE;
gst_element_set_state ((GstElement *) spider, GST_STATE_PAUSED);
}
/* try to autoplug the elements */
if (gst_spider_plug_from_srcpad (conn, pad) != GST_PAD_CONNECT_REFUSED) {
GST_DEBUG (GST_CAT_AUTOPLUG_ATTEMPT, "%s:%s was autoplugged to %s:%s, removing callback", GST_DEBUG_PAD_NAME (pad), GST_DEBUG_PAD_NAME (sinkpad));
g_signal_handler_disconnect (src, signal_id);
signal_id = 0;
}
/* restart if needed */
if (restart)
{
gst_element_set_state ((GstElement *) spider, GST_STATE_PLAYING);
}
}
/* create a new connection from those two elements */
static GstSpiderConnection *
gst_spider_connection_new (GstSpiderIdentity *sink, GstSpiderIdentity *src)
{
GstSpider *spider;
GstSpiderConnection *conn = g_new0 (GstSpiderConnection, 1);
conn->src = src;
conn->sink = sink;
conn->current = (GstElement *) sink;
conn->path = NULL;
spider = GST_SPIDER (GST_OBJECT_PARENT (src));
spider->connections = g_list_prepend (spider->connections, conn);
return conn;
}
static void
gst_spider_connection_destroy (GstSpiderConnection *conn)
{
/* reset connection to unplugged */
gst_spider_connection_reset (conn, (GstElement *) conn->sink);
g_free (conn);
}
static void
gst_spider_connection_reset (GstSpiderConnection *conn, GstElement *to)
{
GST_DEBUG (GST_CAT_AUTOPLUG, "resetting connection from %s to %s, currently at %s to %s", GST_ELEMENT_NAME (conn->sink),
GST_ELEMENT_NAME (conn->src), GST_ELEMENT_NAME (conn->current), GST_ELEMENT_NAME (to));
while ((conn->path != NULL) && ((GstElement *) conn->path->data != to))
{
gst_object_unref ((GstObject *) conn->path->data);
conn->path = g_list_delete_link (conn->path, conn->path);
}
if (conn->path == NULL)
{
conn->current = (GstElement *) conn->sink;
} else {
conn->current = to;
}
}
/* add an element to the connection */
static void
gst_spider_connection_add (GstSpiderConnection *conn, GstElement *element)
{
gst_object_ref ((GstObject *) element);
gst_object_sink ((GstObject *) element);
conn->path = g_list_prepend (conn->path, element);
conn->current = element;
}
/* find the connection from those two elements */
static GstSpiderConnection *
gst_spider_connection_find (GstSpiderIdentity *sink, GstSpiderIdentity *src)
{
GstSpider *spider = (GstSpider *) GST_OBJECT_PARENT (src);
GList *list = spider->connections;
g_assert (spider == (GstSpider *) GST_OBJECT_PARENT (sink));
while (list)
{
GstSpiderConnection *conn = (GstSpiderConnection *) list->data;
if (conn->src == src && conn->sink == sink)
return conn;
list = g_list_next(list);
}
return NULL;
}
/* get a new connection from those two elements
* search first; if none is found, create a new one */
static GstSpiderConnection *
gst_spider_connection_get (GstSpiderIdentity *sink, GstSpiderIdentity *src)
{
GstSpiderConnection *ret;
if ((ret = gst_spider_connection_find (sink, src)) != NULL)
{
return ret;
}
return gst_spider_connection_new (sink, src);
}
void
gst_spider_identity_plug (GstSpiderIdentity *ident)
{
GstSpider *spider;
GList *padlist;
GstPadDirection dir;
GstSpiderConnection *conn;
/* checks */
g_return_if_fail (ident != NULL);
g_return_if_fail (GST_IS_SPIDER_IDENTITY (ident));
spider = GST_SPIDER (GST_ELEMENT_PARENT (ident));
g_assert (spider != NULL);
g_assert (GST_IS_SPIDER (spider));
/* return if we're already plugged */
if (ident->plugged) return;
/* get the direction of our ident */
if (GST_PAD_PEER (ident->sink))
{
if (GST_PAD_PEER (ident->src))
{
/* Hey, the ident is connected on both sides */
g_warning ("Trying to autoplug a connected element. Aborting...");
return;
} else {
dir = GST_PAD_SINK;
}
} else {
if (GST_PAD_PEER (ident->src))
{
dir = GST_PAD_SRC;
} else {
/* the ident isn't connected on either side */
g_warning ("Trying to autoplug an unconnected element. Aborting...");
return;
}
}
/* now iterate all possible pads and connect when needed */
padlist = gst_element_get_pad_list (GST_ELEMENT (spider));
while (padlist)
{
GstPad *otherpad;
GstSpiderIdentity *peer;
g_assert (GST_IS_PAD (padlist->data));
otherpad = (GstPad *) GST_GPAD_REALPAD (padlist->data);
peer = (GstSpiderIdentity *) GST_PAD_PARENT (otherpad);
/* we only want to connect to the other side */
if (dir != GST_PAD_DIRECTION (otherpad))
{
/* we only connect to plugged in elements */
if (peer->plugged == TRUE)
{
/* plug in the right direction */
if (dir == GST_PAD_SINK)
{
conn = gst_spider_connection_get (ident, peer);
} else {
conn = gst_spider_connection_get (peer, ident);
}
if ((GstElement *) conn->sink == conn->current)
{
gst_spider_plug (conn);
}
}
}
padlist = g_list_next (padlist);
}
ident->plugged = TRUE;
}
void
gst_spider_identity_unplug (GstSpiderIdentity *ident)
{
GstSpider *spider = (GstSpider *) GST_OBJECT_PARENT (ident);
GList *list = spider->connections;
while (list)
{
GstSpiderConnection *conn = list->data;
GList *cur = list;
list = g_list_next (list);
if ((conn->src == ident) || (conn->sink == ident))
{
g_list_delete_link (spider->connections, cur);
gst_spider_connection_destroy (conn);
}
}
ident->plugged = FALSE;
}
/* connects src to sink using the elementfactories in plugpath
* plugpath will be removed afterwards */
static GstPadConnectReturn
gst_spider_create_and_plug (GstSpiderConnection *conn, GList *plugpath)
{
GstSpider *spider = (GstSpider *) GST_OBJECT_PARENT (conn->sink);
GList *endelements = NULL, *templist = NULL;
GstElement *element;
/* exit if plugging is already done */
if ((GstElement *) conn->src == conn->current)
return GST_PAD_CONNECT_DONE;
/* try to shorten the list at the end and not duplicate connection code */
if (plugpath != NULL)
{
templist = g_list_last (plugpath);
element = (GstElement *) conn->src;
while ((plugpath != NULL) && (element = gst_spider_find_element_to_plug (element, (GstElementFactory *) plugpath->data, GST_PAD_SINK)))
{
GList *cur = templist;
endelements = g_list_prepend (endelements, element);
templist = g_list_previous (templist);
g_list_delete_link (cur, cur);
}
}
/* do the connecting */
while (conn->current != (GstElement *) (endelements == NULL ? conn->src : endelements->data))
{
/* get sink element to plug, src is conn->current */
if (plugpath == NULL)
{
element = (GstElement *) (endelements == NULL ? conn->src : endelements->data);
} else {
element = gst_element_factory_create ((GstElementFactory *) plugpath->data, NULL);
gst_bin_add (GST_BIN (spider), element);
}
/* insert and connect new element */
if (!gst_element_connect (conn->current, element))
{
/* check if the src has SOMETIMES templates. If so, connect a callback */
GList *templs = gst_element_get_pad_template_list (conn->current);
/* remove element that couldn't be connected, if it wasn't the endpoint */
if (element != (GstElement *) conn->src)
gst_bin_remove (GST_BIN (spider), element);
while (templs) {
GstPadTemplate *templ = (GstPadTemplate *) templs->data;
if ((GST_PAD_TEMPLATE_DIRECTION (templ) == GST_PAD_SRC) && (GST_PAD_TEMPLATE_PRESENCE(templ) == GST_PAD_SOMETIMES))
{
GST_DEBUG (GST_CAT_AUTOPLUG_ATTEMPT, "adding callback to connect element %s to %s", GST_ELEMENT_NAME (conn->current), GST_ELEMENT_NAME (conn->src));
conn->signal_id = g_signal_connect (G_OBJECT (conn->current), "new_pad",
G_CALLBACK (gst_spider_connect_sometimes), conn);
g_list_free (plugpath);
return GST_PAD_CONNECT_DELAYED;
}
templs = g_list_next (templs);
}
GST_DEBUG (GST_CAT_AUTOPLUG_ATTEMPT, "no chance to connect element %s to %s", GST_ELEMENT_NAME (conn->current), GST_ELEMENT_NAME (conn->src));
g_list_free (plugpath);
return GST_PAD_CONNECT_REFUSED;
}
GST_DEBUG (GST_CAT_AUTOPLUG_ATTEMPT, "added element %s and attached it to element %s", GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (conn->current));
gst_spider_connection_add (conn, element);
if (plugpath != NULL)
plugpath = g_list_delete_link (plugpath, plugpath);
}
/* ref all elements at the end */
while (endelements)
{
gst_spider_connection_add (conn, endelements->data);
endelements = g_list_delete_link (endelements, endelements);
}
return GST_PAD_CONNECT_DONE;
}
/* checks, if src is already connected to an element from factory fac on direction dir */
static GstElement *
gst_spider_find_element_to_plug (GstElement *src, GstElementFactory *fac, GstPadDirection dir)
{
GList *padlist = GST_ELEMENT_PADS (src);
while (padlist)
{
GstPad *pad = (GstPad *) GST_PAD_REALIZE (padlist->data);
/* is the pad on the right side and is it connected? */
if ((GST_PAD_DIRECTION (pad) == dir) && (pad = (GstPad *) (GST_RPAD_PEER (pad))))
{
/* is the element the pad is connected to of the right type? */
GstElement *element = GST_PAD_PARENT (pad);
if (GST_ELEMENT_CLASS (G_OBJECT_GET_CLASS (element))->elementfactory == fac) {
return element;
}
}
padlist = g_list_next (padlist);
}
return NULL;
}
/* try to establish the connection */
static GstPadConnectReturn
gst_spider_plug (GstSpiderConnection *conn)
{
if ((GstElement *) conn->src == conn->current)
return GST_PAD_CONNECT_DONE;
if ((GstElement *) conn->sink == conn->current)
return gst_spider_plug_from_srcpad (conn, conn->sink->src);
g_warning ("FIXME: autoplugging only possible from GstSpiderIdentity conn->sink yet (yep, that's technical)\n");
return GST_PAD_CONNECT_REFUSED;
}
/* try to establish the connection using this pad */
static GstPadConnectReturn
gst_spider_plug_from_srcpad (GstSpiderConnection *conn, GstPad *srcpad)
{
GstElement *element;
GList *plugpath;
gboolean result = TRUE;
GstSpider *spider = (GstSpider *) GST_OBJECT_PARENT (conn->src);
GstElement *startelement = conn->current;
g_assert ((GstElement *) GST_OBJECT_PARENT (srcpad) == conn->current);
GST_DEBUG (GST_CAT_AUTOPLUG_ATTEMPT, "trying to plug from %s:%s to %s", GST_DEBUG_PAD_NAME (srcpad), GST_ELEMENT_NAME (conn->src));
/* find a path from src to sink */
/* FIXME: make that if go away and work anyway */
if (srcpad == conn->sink->src)
{
g_assert (GST_RPAD_PEER (conn->sink->sink) != NULL);
plugpath = gst_autoplug_sp (gst_pad_get_caps ((GstPad *) GST_RPAD_PEER (conn->sink->sink)), gst_pad_get_caps (conn->src->sink), spider->factories);
} else {
plugpath = gst_autoplug_sp (gst_pad_get_caps (srcpad), gst_pad_get_caps (conn->src->sink), spider->factories);
}
/* prints out the path that was found for plugging */
/* g_print ("found path from %s to %s:\n", GST_ELEMENT_NAME (conn->current), GST_ELEMENT_NAME (conn->src));
templist = plugpath;
while (templist)
{
g_print("%s\n", GST_OBJECT_NAME (templist->data));
templist = g_list_next (templist);
}*/
/* if there is no way to plug: return */
if (plugpath == NULL) {
GST_DEBUG (GST_CAT_AUTOPLUG_ATTEMPT, "no chance to plug from %s to %s", GST_ELEMENT_NAME (conn->current), GST_ELEMENT_NAME (conn->src));
return GST_PAD_CONNECT_REFUSED;
}
GST_DEBUG (GST_CAT_AUTOPLUG_ATTEMPT, "found a connection that needs %d elements", g_list_length (plugpath));
/* now remove non-needed elements from the beginning of the path
* alter src to point to the new element where we need to start
* plugging and alter the plugpath to represent the elements, that must be plugged
*/
element = conn->current;
while ((plugpath != NULL) && (element = gst_spider_find_element_to_plug (element, (GstElementFactory *) plugpath->data, GST_PAD_SRC)))
{
gst_spider_connection_add (conn, element);
plugpath = g_list_delete_link (plugpath, plugpath);
}
GST_DEBUG (GST_CAT_AUTOPLUG_ATTEMPT, "%d elements must be inserted to establish the connection", g_list_length (plugpath));
/* create the elements and plug them */
result = gst_spider_create_and_plug (conn, plugpath);
/* reset the "current" element */
if (result == GST_PAD_CONNECT_REFUSED)
{
gst_spider_connection_reset (conn, startelement);
}
return result;
}
GstElementDetails gst_spider_details = {
"Spider",
"Generic",
"Automatically connect sinks and sources",
VERSION,
"Benjamin Otte <in7y118@public.uni-hamburg.de>",
"(C) 2002",
};
static gboolean
plugin_init (GModule *module, GstPlugin *plugin)
{
GstElementFactory *factory;
factory = gst_element_factory_new("spider", GST_TYPE_SPIDER,
&gst_spider_details);
g_return_val_if_fail(factory != NULL, FALSE);
gst_element_factory_add_pad_template (factory, GST_PAD_TEMPLATE_GET (spider_src_factory));
gst_element_factory_add_pad_template (factory, GST_PAD_TEMPLATE_GET (spider_sink_factory));
gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE (factory));
return TRUE;
}
GstPluginDesc plugin_desc = {
GST_VERSION_MAJOR,
GST_VERSION_MINOR,
"gstspider",
plugin_init
};