/* GStreamer * Copyright (c) 2005 Ronald S. Bultje * Copyright (c) 2006 Jürg Billeter * Copyright (c) 2007 Jan Schmidt * Copyright (c) 2010 Sebastian Dröge * * 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. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include "gstswitchsrc.h" GST_DEBUG_CATEGORY_STATIC (switch_debug); #define GST_CAT_DEFAULT switch_debug static void gst_switch_src_dispose (GObject * object); static GstStateChangeReturn gst_switch_src_change_state (GstElement * element, GstStateChange transition); GST_BOILERPLATE (GstSwitchSrc, gst_switch_src, GstBin, GST_TYPE_BIN); static void gst_switch_src_base_init (gpointer klass) { GST_DEBUG_CATEGORY_INIT (switch_debug, "switchsrc", 0, "switchsrc element"); } static void gst_switch_src_class_init (GstSwitchSrcClass * klass) { GObjectClass *oklass = G_OBJECT_CLASS (klass); GstElementClass *eklass = GST_ELEMENT_CLASS (klass); static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS, GST_STATIC_CAPS_ANY); GstPadTemplate *child_pad_templ; oklass->dispose = gst_switch_src_dispose; eklass->change_state = gst_switch_src_change_state; /* Provide a default pad template if the child didn't */ child_pad_templ = gst_element_class_get_pad_template (eklass, "src"); if (child_pad_templ == NULL) { gst_element_class_add_pad_template (eklass, gst_static_pad_template_get (&src_template)); } } static gboolean gst_switch_src_reset (GstSwitchSrc * src) { /* this will install fakesrc if no other child has been set, * otherwise we rely on the subclass to know when to unset its * custom kid */ if (src->kid == NULL) { return gst_switch_src_set_child (src, NULL); } return TRUE; } static void gst_switch_src_init (GstSwitchSrc * src, GstSwitchSrcClass * g_class) { GstElementClass *eklass = GST_ELEMENT_GET_CLASS (src); GstPadTemplate *templ; templ = gst_element_class_get_pad_template (eklass, "src"); src->pad = gst_ghost_pad_new_no_target_from_template ("src", templ); gst_element_add_pad (GST_ELEMENT (src), src->pad); gst_switch_src_reset (src); GST_OBJECT_FLAG_SET (src, GST_ELEMENT_IS_SOURCE); } static void gst_switch_src_dispose (GObject * object) { GstSwitchSrc *src = GST_SWITCH_SRC (object); GstObject *new_kid, *kid; GST_OBJECT_LOCK (src); new_kid = GST_OBJECT_CAST (src->new_kid); src->new_kid = NULL; kid = GST_OBJECT_CAST (src->kid); src->kid = NULL; GST_OBJECT_UNLOCK (src); gst_object_replace (&new_kid, NULL); gst_object_replace (&kid, NULL); GST_CALL_PARENT (G_OBJECT_CLASS, dispose, (object)); } static gboolean gst_switch_src_commit_new_kid (GstSwitchSrc * src) { GstPad *targetpad; GstState kid_state; GstElement *new_kid, *old_kid; gboolean is_fakesrc = FALSE; GstBus *bus; /* need locking around member accesses */ GST_OBJECT_LOCK (src); /* If we're currently changing state, set the child to the next state * we're transitioning too, rather than our current state which is * about to change */ if (GST_STATE_NEXT (src) != GST_STATE_VOID_PENDING) kid_state = GST_STATE_NEXT (src); else kid_state = GST_STATE (src); new_kid = src->new_kid ? gst_object_ref (src->new_kid) : NULL; src->new_kid = NULL; GST_OBJECT_UNLOCK (src); /* Fakesrc by default if NULL is passed as the new child */ if (new_kid == NULL) { GST_DEBUG_OBJECT (src, "Replacing kid with fakesrc"); new_kid = gst_element_factory_make ("fakesrc", "testsrc"); if (new_kid == NULL) { GST_ERROR_OBJECT (src, "Failed to create fakesrc"); return FALSE; } /* Add a reference, as it would if the element came from src->new_kid */ gst_object_ref (new_kid); is_fakesrc = TRUE; } else { GST_DEBUG_OBJECT (src, "Setting new kid"); } /* set temporary bus of our own to catch error messages from the child * (could we just set our own bus on it, or would the state change messages * from the not-yet-added element confuse the state change algorithm? Let's * play it safe for now) */ bus = gst_bus_new (); gst_element_set_bus (new_kid, bus); gst_object_unref (bus); if (gst_element_set_state (new_kid, kid_state) == GST_STATE_CHANGE_FAILURE) { GstMessage *msg; /* check if child posted an error message and if so re-post it on our bus * so that the application gets to see a decent error and not our generic * fallback error message which is completely indecipherable to the user */ msg = gst_bus_pop_filtered (GST_ELEMENT_BUS (new_kid), GST_MESSAGE_ERROR); if (msg) { GST_INFO_OBJECT (src, "Forwarding kid error: %" GST_PTR_FORMAT, msg); gst_element_post_message (GST_ELEMENT (src), msg); } GST_ELEMENT_ERROR (src, CORE, STATE_CHANGE, (NULL), ("Failed to set state on new child.")); gst_element_set_bus (new_kid, NULL); gst_object_unref (new_kid); return FALSE; } gst_element_set_bus (new_kid, NULL); gst_bin_add (GST_BIN (src), new_kid); /* Now, replace the existing child */ GST_OBJECT_LOCK (src); old_kid = src->kid; src->kid = new_kid; /* Mark whether a custom kid or fakesrc has been installed */ src->have_kid = !is_fakesrc; GST_OBJECT_UNLOCK (src); /* kill old element */ if (old_kid) { GST_DEBUG_OBJECT (src, "Removing old kid %" GST_PTR_FORMAT, old_kid); gst_element_set_state (old_kid, GST_STATE_NULL); gst_bin_remove (GST_BIN (src), old_kid); gst_object_unref (old_kid); /* Don't lose the SOURCE flag */ GST_OBJECT_FLAG_SET (src, GST_ELEMENT_IS_SOURCE); } /* re-attach ghostpad */ GST_DEBUG_OBJECT (src, "Creating new ghostpad"); targetpad = gst_element_get_static_pad (src->kid, "src"); gst_ghost_pad_set_target (GST_GHOST_PAD (src->pad), targetpad); gst_object_unref (targetpad); GST_DEBUG_OBJECT (src, "done changing child of switchsrc"); return TRUE; } gboolean gst_switch_src_set_child (GstSwitchSrc * src, GstElement * new_kid) { GstState cur, next; GstElement **p_kid; /* Nothing to do if clearing the child and we've already installed fakesrc */ if (new_kid == NULL && src->kid != NULL && src->have_kid == FALSE) return TRUE; /* Store the new kid to be committed later */ GST_OBJECT_LOCK (src); cur = GST_STATE (src); next = GST_STATE_NEXT (src); p_kid = &src->new_kid; gst_object_replace ((GstObject **) p_kid, (GstObject *) new_kid); GST_OBJECT_UNLOCK (src); if (new_kid) gst_object_unref (new_kid); /* Sometime, it would be lovely to allow src changes even when * already running */ /* FIXME: Block the pad and replace the kid when it completes */ if (cur > GST_STATE_READY || next == GST_STATE_PAUSED) { GST_DEBUG_OBJECT (src, "Switch-src is already running. Ignoring change of child."); gst_object_unref (new_kid); return TRUE; } return gst_switch_src_commit_new_kid (src); } static GstStateChangeReturn gst_switch_src_change_state (GstElement * element, GstStateChange transition) { GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS; GstSwitchSrc *src = GST_SWITCH_SRC (element); ret = GST_CALL_PARENT_WITH_DEFAULT (GST_ELEMENT_CLASS, change_state, (element, transition), GST_STATE_CHANGE_SUCCESS); switch (transition) { case GST_STATE_CHANGE_READY_TO_NULL: if (!gst_switch_src_reset (src)) ret = GST_STATE_CHANGE_FAILURE; break; default: break; } return ret; }