/* GStreamer * Copyright (C) 2002 Erik Walthinsen * 2002 Wim Taymans * * gstspider.c: element to automatically link 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 unlinking * - 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 */ ); /* 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); /* link functions */ static GstSpiderConnection * gst_spider_link_new (GstSpiderIdentity *src); static void gst_spider_link_destroy (GstSpiderConnection *conn); static void gst_spider_link_reset (GstSpiderConnection *conn, GstElement *to); static void gst_spider_link_add (GstSpiderConnection *conn, GstElement *element); static GstSpiderConnection * gst_spider_link_find (GstSpiderIdentity *src); static GstSpiderConnection * gst_spider_link_get (GstSpiderIdentity *src); /* autoplugging functions */ static GstElement * gst_spider_find_element_to_plug (GstElement *src, GstElementFactory *fac, GstPadDirection dir); static GstPadLinkReturn gst_spider_plug (GstSpiderConnection *conn); static GstPadLinkReturn gst_spider_plug_from_srcpad (GstSpiderConnection *conn, GstPad *srcpad); /*static GstPadLinkReturn gst_spider_plug_peers (GstSpider *spider, GstPad *srcpad, GstPad *sinkpad); */ static GstPadLinkReturn 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_link (GstSpiderConnection *conn); */ /* === variables === */ static GstElementClass * parent_class = NULL; /* no signals yet static guint gst_spider_signals[LAST_SIGNAL] = { 0 };*/ /* 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_PAD_TEMPLATE_GET (spider_src_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->links = NULL; spider->sink_ident = gst_spider_identity_new_sink ("sink_ident"); gst_bin_add (GST_BIN (spider), GST_ELEMENT (spider->sink_ident)); gst_element_add_ghost_pad (GST_ELEMENT(spider), spider->sink_ident->sink, "sink"); } 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); g_return_val_if_fail (GST_PAD_TEMPLATE_DIRECTION (templ) == GST_PAD_SRC, NULL); spider = GST_SPIDER (element); /* create an identity object, so we have a pad */ padname = gst_spider_unused_elementname ((GstBin *)spider, "src_"); identity = gst_spider_identity_new_src (padname); returnpad = identity->src; /* 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_spider_link_new (identity); 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_link_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->src)); /* 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_LINK_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 link from those two elements */ static GstSpiderConnection * gst_spider_link_new (GstSpiderIdentity *src) { GstSpider *spider = GST_SPIDER (GST_OBJECT_PARENT (src)); GstSpiderConnection *conn = g_new0 (GstSpiderConnection, 1); conn->src = src; conn->path = NULL; conn->current = (GstElement *) spider->sink_ident; spider->links = g_list_prepend (spider->links, conn); return conn; } static void gst_spider_link_destroy (GstSpiderConnection *conn) { GstSpider *spider = GST_SPIDER (GST_OBJECT_PARENT (conn->src)); /* reset link to unplugged */ gst_spider_link_reset (conn, (GstElement *) spider->sink_ident); g_free (conn); } static void gst_spider_link_reset (GstSpiderConnection *conn, GstElement *to) { GstSpider *spider = GST_SPIDER (GST_OBJECT_PARENT (conn->src)); GST_DEBUG (GST_CAT_AUTOPLUG, "resetting link from %s to %s, currently at %s to %s", GST_ELEMENT_NAME (spider->sink_ident), 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 *) spider->sink_ident; } else { conn->current = to; } } /* add an element to the link */ static void gst_spider_link_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 link from those two elements */ static GstSpiderConnection * gst_spider_link_find (GstSpiderIdentity *src) { GstSpider *spider = (GstSpider *) GST_OBJECT_PARENT (src); GList *list = spider->links; while (list) { GstSpiderConnection *conn = (GstSpiderConnection *) list->data; if (conn->src == src){ return conn; } list = g_list_next(list); } return NULL; } /* get a new link from those two elements * search first; if none is found, create a new one */ static GstSpiderConnection * gst_spider_link_get (GstSpiderIdentity *src) { GstSpiderConnection *ret; if ((ret = gst_spider_link_find (src)) != NULL) { return ret; } return gst_spider_link_new (src); } void gst_spider_identity_plug (GstSpiderIdentity *ident) { GstSpider *spider; const 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 linked on both sides */ g_warning ("Trying to autoplug a linked element. Aborting..."); return; } else { dir = GST_PAD_SINK; } } else { if (GST_PAD_PEER (ident->src)) { dir = GST_PAD_SRC; } else { /* the ident isn't linked on either side */ g_warning ("Trying to autoplug an unlinked element. Aborting..."); return; } } /* now iterate all possible pads and link 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 link to the other side */ if (dir != GST_PAD_DIRECTION (otherpad)) { /* we only link to plugged in elements */ if (peer->plugged == TRUE) { /* plug in the right direction */ if (dir == GST_PAD_SINK) { conn = gst_spider_link_get (peer); } else { conn = gst_spider_link_get (ident); } if ((GstElement *) spider->sink_ident == conn->current) { gboolean restart = FALSE; /* 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); } gst_spider_plug (conn); /* restart if needed */ if (restart) { gst_element_set_state ((GstElement *) spider, GST_STATE_PLAYING); } } } } 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->links; while (list) { GstSpiderConnection *conn = list->data; GList *cur = list; list = g_list_next (list); if (conn->src == ident) { g_list_delete_link (spider->links, cur); gst_spider_link_destroy (conn); } } ident->plugged = FALSE; } /* links src to sink using the elementfactories in plugpath * plugpath will be removed afterwards */ static GstPadLinkReturn gst_spider_create_and_plug (GstSpiderConnection *conn, GList *plugpath) { GstSpider *spider = (GstSpider *) GST_OBJECT_PARENT (conn->src); GList *endelements = NULL, *templist = NULL; GstElement *element; /* exit if plugging is already done */ if ((GstElement *) conn->src == conn->current) return GST_PAD_LINK_DONE; /* try to shorten the list at the end and not duplicate link 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 linking */ 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); gst_element_sync_state_with_parent (element); } /* insert and link new element */ if (!gst_element_link (conn->current, element)) { /* check if the src has SOMETIMES templates. If so, link a callback */ GList *templs = gst_element_get_pad_template_list (conn->current); /* remove element that couldn't be linked, 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 link 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_link_sometimes), conn); g_list_free (plugpath); return GST_PAD_LINK_DELAYED; } templs = g_list_next (templs); } GST_DEBUG (GST_CAT_AUTOPLUG_ATTEMPT, "no chance to link element %s to %s", GST_ELEMENT_NAME (conn->current), GST_ELEMENT_NAME (conn->src)); g_list_free (plugpath); return GST_PAD_LINK_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_link_add (conn, element); if (plugpath != NULL) plugpath = g_list_delete_link (plugpath, plugpath); } /* ref all elements at the end */ while (endelements) { gst_spider_link_add (conn, endelements->data); endelements = g_list_delete_link (endelements, endelements); } return GST_PAD_LINK_DONE; } /* checks, if src is already linked 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 linked? */ if ((GST_PAD_DIRECTION (pad) == dir) && (pad = (GstPad *) (GST_RPAD_PEER (pad)))) { /* is the element the pad is linked 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 link */ static GstPadLinkReturn gst_spider_plug (GstSpiderConnection *conn) { GstSpider *spider = (GstSpider *) GST_OBJECT_PARENT (conn->src); if ((GstElement *) conn->src == conn->current) return GST_PAD_LINK_DONE; if ((GstElement *) spider->sink_ident == conn->current) return gst_spider_plug_from_srcpad (conn, spider->sink_ident->src); g_warning ("FIXME: autoplugging only possible from GstSpiderIdentity conn->sink yet (yep, that's technical)\n"); return GST_PAD_LINK_REFUSED; } /* try to establish the link using this pad */ static GstPadLinkReturn 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 == spider->sink_ident->src) { g_assert (GST_RPAD_PEER (spider->sink_ident->sink) != NULL); plugpath = gst_autoplug_sp (gst_pad_get_caps ((GstPad *) GST_RPAD_PEER (spider->sink_ident->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_LINK_REFUSED; } GST_DEBUG (GST_CAT_AUTOPLUG_ATTEMPT, "found a link 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_link_add (conn, element); plugpath = g_list_delete_link (plugpath, plugpath); } GST_DEBUG (GST_CAT_AUTOPLUG_ATTEMPT, "%d elements must be inserted to establish the link", 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_LINK_REFUSED) { gst_spider_link_reset (conn, startelement); } return result; } GstElementDetails gst_spider_details = { "Spider", "Generic", "LGPL", "Automatically link sinks and sources", VERSION, "Benjamin Otte ", "(C) 2002", }; static gboolean plugin_init (GModule *module, GstPlugin *plugin) { GstElementFactory *factory; factory = gst_element_factory_new("spider", GST_TYPE_SPIDER, &gst_spider_details); gst_plugin_set_longname (plugin, "Spider autoplugging elements"); g_return_val_if_fail(factory != NULL, FALSE); gst_element_factory_add_pad_template (factory, GST_PAD_TEMPLATE_GET (spider_src_factory)); gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE (factory)); /* add spideridentity */ factory = gst_element_factory_new ("spideridentity", GST_TYPE_SPIDER_IDENTITY, &gst_spider_identity_details); gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE (factory)); return TRUE; } GstPluginDesc plugin_desc = { GST_VERSION_MAJOR, GST_VERSION_MINOR, "gstspider", plugin_init };