/* GStreamer * Copyright (C) 1999,2000 Erik Walthinsen * 2000 Wim Taymans * * gstpad.c: Pads for linking elements together * * 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. */ /** * SECTION:gstpad * @short_description: Object contained by elements that allows links to * other elements * @see_also: #GstPadTemplate, #GstElement, #GstEvent * * A #GstElement is linked to other elements via "pads", which are extremely * light-weight generic link points. * After two pads are retrieved from an element with gst_element_get_pad(), * the pads can be link with gst_pad_link(). (For quick links, * you can also use gst_element_link(), which will make the obvious * link for you if it's straightforward.) * * Pads are typically created from a #GstPadTemplate with * gst_pad_new_from_template(). * * Pads have #GstCaps attached to it to describe the media type they are * capable of dealing with. gst_pad_get_caps() and gst_pad_set_caps() are * used to manipulate the caps of the pads. * Pads created from a pad template cannot set capabilities that are * incompatible with the pad template capabilities. * * Pads without pad templates can be created with gst_pad_new(), * which takes a direction and a name as an argument. If the name is NULL, * then a guaranteed unique name will be assigned to it. * * gst_pad_get_parent() will retrieve the #GstElement that owns the pad. * * A #GstElement creating a pad will typically use the various * gst_pad_set_*_function() calls to register callbacks for various events * on the pads. * * GstElements will use gst_pad_push() and gst_pad_pull_range() to push out * or pull in a buffer. * * To send a #GstEvent on a pad, use gst_pad_send_event() and * gst_pad_push_event(). * * Last reviewed on 2006-07-06 (0.10.9) */ #include "gst_private.h" #include "gstpad.h" #include "gstpadtemplate.h" #include "gstenumtypes.h" #include "gstmarshal.h" #include "gstutils.h" #include "gstinfo.h" #include "gsterror.h" #include "gstvalue.h" #include "glib-compat-private.h" GST_DEBUG_CATEGORY_STATIC (debug_dataflow); #define GST_CAT_DEFAULT GST_CAT_PADS /* Pad signals and args */ enum { PAD_LINKED, PAD_UNLINKED, PAD_REQUEST_LINK, PAD_HAVE_DATA, /* FILL ME */ LAST_SIGNAL }; enum { PAD_PROP_0, PAD_PROP_CAPS, PAD_PROP_DIRECTION, PAD_PROP_TEMPLATE, /* FILL ME */ }; static void gst_pad_class_init (GstPadClass * klass); static void gst_pad_init (GstPad * pad); static void gst_pad_dispose (GObject * object); static void gst_pad_finalize (GObject * object); static void gst_pad_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec); static void gst_pad_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec); static GstFlowReturn handle_pad_block (GstPad * pad); static GstCaps *gst_pad_get_caps_unlocked (GstPad * pad); static void gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ); static gboolean gst_pad_activate_default (GstPad * pad); static gboolean gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps); #ifndef GST_DISABLE_LOADSAVE static xmlNodePtr gst_pad_save_thyself (GstObject * object, xmlNodePtr parent); #endif static GstObjectClass *parent_class = NULL; static guint gst_pad_signals[LAST_SIGNAL] = { 0 }; /* quarks for probe signals */ static GQuark buffer_quark; static GQuark event_quark; typedef struct { const gint ret; const gchar *name; GQuark quark; } GstFlowQuarks; static GstFlowQuarks flow_quarks[] = { {GST_FLOW_CUSTOM_SUCCESS, "custom-success", 0}, {GST_FLOW_RESEND, "resend", 0}, {GST_FLOW_OK, "ok", 0}, {GST_FLOW_NOT_LINKED, "not-linked", 0}, {GST_FLOW_WRONG_STATE, "wrong-state", 0}, {GST_FLOW_UNEXPECTED, "unexpected", 0}, {GST_FLOW_NOT_NEGOTIATED, "not-negotiated", 0}, {GST_FLOW_ERROR, "error", 0}, {GST_FLOW_NOT_SUPPORTED, "not-supported", 0}, {GST_FLOW_CUSTOM_ERROR, "custom-error", 0}, {0, NULL, 0} }; /** * gst_flow_get_name: * @ret: a #GstFlowReturn to get the name of. * * Gets a string representing the given flow return. * * Returns: a static string with the name of the flow return. */ G_CONST_RETURN gchar * gst_flow_get_name (GstFlowReturn ret) { gint i; ret = CLAMP (ret, GST_FLOW_CUSTOM_ERROR, GST_FLOW_CUSTOM_SUCCESS); for (i = 0; flow_quarks[i].name; i++) { if (ret == flow_quarks[i].ret) return flow_quarks[i].name; } return "unknown"; } /** * gst_flow_to_quark: * @ret: a #GstFlowReturn to get the quark of. * * Get the unique quark for the given GstFlowReturn. * * Returns: the quark associated with the flow return or 0 if an * invalid return was specified. */ GQuark gst_flow_to_quark (GstFlowReturn ret) { gint i; ret = CLAMP (ret, GST_FLOW_CUSTOM_ERROR, GST_FLOW_CUSTOM_SUCCESS); for (i = 0; flow_quarks[i].name; i++) { if (ret == flow_quarks[i].ret) return flow_quarks[i].quark; } return 0; } GType gst_pad_get_type (void) { static GType gst_pad_type = 0; if (G_UNLIKELY (gst_pad_type == 0)) { static const GTypeInfo pad_info = { sizeof (GstPadClass), NULL, NULL, (GClassInitFunc) gst_pad_class_init, NULL, NULL, sizeof (GstPad), 0, (GInstanceInitFunc) gst_pad_init, NULL }; gint i; gst_pad_type = g_type_register_static (GST_TYPE_OBJECT, "GstPad", &pad_info, 0); buffer_quark = g_quark_from_static_string ("buffer"); event_quark = g_quark_from_static_string ("event"); for (i = 0; flow_quarks[i].name; i++) { flow_quarks[i].quark = g_quark_from_static_string (flow_quarks[i].name); } GST_DEBUG_CATEGORY_INIT (debug_dataflow, "GST_DATAFLOW", GST_DEBUG_BOLD | GST_DEBUG_FG_GREEN, "dataflow inside pads"); } return gst_pad_type; } static gboolean _gst_do_pass_data_accumulator (GSignalInvocationHint * ihint, GValue * return_accu, const GValue * handler_return, gpointer dummy) { gboolean ret = g_value_get_boolean (handler_return); GST_DEBUG ("accumulated %d", ret); g_value_set_boolean (return_accu, ret); return ret; } static gboolean default_have_data (GstPad * pad, GstMiniObject * o) { return TRUE; } static void gst_pad_class_init (GstPadClass * klass) { GObjectClass *gobject_class; GstObjectClass *gstobject_class; gobject_class = G_OBJECT_CLASS (klass); gstobject_class = GST_OBJECT_CLASS (klass); parent_class = g_type_class_peek_parent (klass); gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_pad_dispose); gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_pad_finalize); gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_pad_set_property); gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_pad_get_property); /** * GstPad::linked: * @pad: the pad that emitted the signal * @peer: the peer pad that has been connected * * Signals that a pad has been linked to the peer pad. */ gst_pad_signals[PAD_LINKED] = g_signal_new ("linked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstPadClass, linked), NULL, NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD); /** * GstPad::unlinked: * @pad: the pad that emitted the signal * @peer: the peer pad that has been disconnected * * Signals that a pad has been unlinked from the peer pad. */ gst_pad_signals[PAD_UNLINKED] = g_signal_new ("unlinked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstPadClass, unlinked), NULL, NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD); /** * GstPad::request-link: * @pad: the pad that emitted the signal * @peer: the peer pad for which a connection is requested * * Signals that a pad connection has been requested. */ gst_pad_signals[PAD_REQUEST_LINK] = g_signal_new ("request-link", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstPadClass, request_link), NULL, NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 0); /** * GstPad::have-data: * @pad: the pad that emitted the signal * @mini_obj: new data * * Signals that new data is available on the pad. This signal is used * internally for implementing pad probes. * See gst_pad_add_*_probe functions. * * Returns: %TRUE to keep the data, %FALSE to drop it */ gst_pad_signals[PAD_HAVE_DATA] = g_signal_new ("have-data", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST | G_SIGNAL_DETAILED, G_STRUCT_OFFSET (GstPadClass, have_data), _gst_do_pass_data_accumulator, NULL, gst_marshal_BOOLEAN__POINTER, G_TYPE_BOOLEAN, 1, GST_TYPE_MINI_OBJECT); g_object_class_install_property (gobject_class, PAD_PROP_CAPS, g_param_spec_boxed ("caps", "Caps", "The capabilities of the pad", GST_TYPE_CAPS, G_PARAM_READABLE)); g_object_class_install_property (gobject_class, PAD_PROP_DIRECTION, g_param_spec_enum ("direction", "Direction", "The direction of the pad", GST_TYPE_PAD_DIRECTION, GST_PAD_UNKNOWN, G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY)); /* FIXME, Make G_PARAM_CONSTRUCT_ONLY when we fix ghostpads. */ g_object_class_install_property (gobject_class, PAD_PROP_TEMPLATE, g_param_spec_object ("template", "Template", "The GstPadTemplate of this pad", GST_TYPE_PAD_TEMPLATE, G_PARAM_READWRITE)); #ifndef GST_DISABLE_LOADSAVE gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_pad_save_thyself); #endif gstobject_class->path_string_separator = "."; klass->have_data = default_have_data; } static void gst_pad_init (GstPad * pad) { GST_PAD_DIRECTION (pad) = GST_PAD_UNKNOWN; GST_PAD_PEER (pad) = NULL; GST_PAD_CHAINFUNC (pad) = NULL; GST_PAD_LINKFUNC (pad) = NULL; GST_PAD_CAPS (pad) = NULL; GST_PAD_GETCAPSFUNC (pad) = NULL; GST_PAD_ACTIVATEFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_activate_default); GST_PAD_EVENTFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_event_default); GST_PAD_QUERYTYPEFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_get_query_types_default); GST_PAD_QUERYFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_query_default); GST_PAD_INTLINKFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_get_internal_links_default); GST_PAD_ACCEPTCAPSFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_acceptcaps_default); pad->do_buffer_signals = 0; pad->do_event_signals = 0; GST_PAD_SET_FLUSHING (pad); pad->preroll_lock = g_mutex_new (); pad->preroll_cond = g_cond_new (); pad->stream_rec_lock = g_new (GStaticRecMutex, 1); g_static_rec_mutex_init (pad->stream_rec_lock); pad->block_cond = g_cond_new (); } static void gst_pad_dispose (GObject * object) { GstPad *pad = GST_PAD (object); GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, pad, "dispose"); /* we don't hold a ref to the peer so we can just set the * peer to NULL. */ GST_PAD_PEER (pad) = NULL; /* clear the caps */ gst_caps_replace (&GST_PAD_CAPS (pad), NULL); gst_pad_set_pad_template (pad, NULL); G_OBJECT_CLASS (parent_class)->dispose (object); } static void gst_pad_finalize (GObject * object) { GstPad *pad = GST_PAD (object); GstTask *task; /* in case the task is still around, clean it up */ if ((task = GST_PAD_TASK (pad))) { gst_task_join (task); GST_PAD_TASK (pad) = NULL; gst_object_unref (task); } if (pad->stream_rec_lock) { g_static_rec_mutex_free (pad->stream_rec_lock); g_free (pad->stream_rec_lock); pad->stream_rec_lock = NULL; } if (pad->preroll_lock) { g_mutex_free (pad->preroll_lock); g_cond_free (pad->preroll_cond); pad->preroll_lock = NULL; pad->preroll_cond = NULL; } if (pad->block_cond) { g_cond_free (pad->block_cond); pad->block_cond = NULL; } G_OBJECT_CLASS (parent_class)->finalize (object); } static void gst_pad_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec) { g_return_if_fail (GST_IS_PAD (object)); switch (prop_id) { case PAD_PROP_DIRECTION: GST_PAD_DIRECTION (object) = g_value_get_enum (value); break; case PAD_PROP_TEMPLATE: gst_pad_set_pad_template (GST_PAD_CAST (object), (GstPadTemplate *) g_value_get_object (value)); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_pad_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec) { g_return_if_fail (GST_IS_PAD (object)); switch (prop_id) { case PAD_PROP_CAPS: GST_OBJECT_LOCK (object); g_value_set_boxed (value, GST_PAD_CAPS (object)); GST_OBJECT_UNLOCK (object); break; case PAD_PROP_DIRECTION: g_value_set_enum (value, GST_PAD_DIRECTION (object)); break; case PAD_PROP_TEMPLATE: g_value_set_object (value, GST_PAD_PAD_TEMPLATE (object)); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } /** * gst_pad_new: * @name: the name of the new pad. * @direction: the #GstPadDirection of the pad. * * Creates a new pad with the given name in the given direction. * If name is NULL, a guaranteed unique name (across all pads) * will be assigned. * This function makes a copy of the name so you can safely free the name. * * Returns: a new #GstPad, or NULL in case of an error. * * MT safe. */ GstPad * gst_pad_new (const gchar * name, GstPadDirection direction) { return g_object_new (GST_TYPE_PAD, "name", name, "direction", direction, NULL); } /** * gst_pad_new_from_template: * @templ: the pad template to use * @name: the name of the element * * Creates a new pad with the given name from the given template. * If name is NULL, a guaranteed unique name (across all pads) * will be assigned. * This function makes a copy of the name so you can safely free the name. * * Returns: a new #GstPad, or NULL in case of an error. */ GstPad * gst_pad_new_from_template (GstPadTemplate * templ, const gchar * name) { g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL); return g_object_new (GST_TYPE_PAD, "name", name, "direction", templ->direction, "template", templ, NULL); } /** * gst_pad_new_from_static_template: * @templ: the #GstStaticPadTemplate to use * @name: the name of the element * * Creates a new pad with the given name from the given static template. * If name is NULL, a guaranteed unique name (across all pads) * will be assigned. * This function makes a copy of the name so you can safely free the name. * * Returns: a new #GstPad, or NULL in case of an error. */ GstPad * gst_pad_new_from_static_template (GstStaticPadTemplate * templ, const gchar * name) { GstPad *pad; GstPadTemplate *template; template = gst_static_pad_template_get (templ); pad = gst_pad_new_from_template (template, name); gst_object_unref (template); return pad; } /** * gst_pad_get_direction: * @pad: a #GstPad to get the direction of. * * Gets the direction of the pad. The direction of the pad is * decided at construction time so this function does not take * the LOCK. * * Returns: the #GstPadDirection of the pad. * * MT safe. */ GstPadDirection gst_pad_get_direction (GstPad * pad) { GstPadDirection result; /* PAD_UNKNOWN is a little silly but we need some sort of * error return value */ g_return_val_if_fail (GST_IS_PAD (pad), GST_PAD_UNKNOWN); GST_OBJECT_LOCK (pad); result = GST_PAD_DIRECTION (pad); GST_OBJECT_UNLOCK (pad); return result; } static gboolean gst_pad_activate_default (GstPad * pad) { return gst_pad_activate_push (pad, TRUE); } static void pre_activate (GstPad * pad, GstActivateMode new_mode) { switch (new_mode) { case GST_ACTIVATE_PUSH: case GST_ACTIVATE_PULL: GST_OBJECT_LOCK (pad); GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d, unset flushing", new_mode); GST_PAD_UNSET_FLUSHING (pad); GST_PAD_ACTIVATE_MODE (pad) = new_mode; GST_OBJECT_UNLOCK (pad); break; case GST_ACTIVATE_NONE: GST_OBJECT_LOCK (pad); GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE NONE, set flushing"); GST_PAD_SET_FLUSHING (pad); /* unlock blocked pads so element can resume and stop */ GST_PAD_BLOCK_BROADCAST (pad); GST_OBJECT_UNLOCK (pad); break; } } static void post_activate (GstPad * pad, GstActivateMode new_mode) { switch (new_mode) { case GST_ACTIVATE_PUSH: case GST_ACTIVATE_PULL: /* nop */ break; case GST_ACTIVATE_NONE: /* ensures that streaming stops */ GST_PAD_STREAM_LOCK (pad); /* while we're at it set activation mode */ GST_OBJECT_LOCK (pad); GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d", new_mode); GST_PAD_ACTIVATE_MODE (pad) = new_mode; GST_OBJECT_UNLOCK (pad); GST_PAD_STREAM_UNLOCK (pad); break; } } /** * gst_pad_set_active: * @pad: the #GstPad to activate or deactivate. * @active: whether or not the pad should be active. * * Activates or deactivates the given pad. * Normally called from within core state change functions. * * If @active, makes sure the pad is active. If it is already active, either in * push or pull mode, just return. Otherwise dispatches to the pad's activate * function to perform the actual activation. * * If not @active, checks the pad's current mode and calls * gst_pad_activate_push() or gst_pad_activate_pull(), as appropriate, with a * FALSE argument. * * Returns: #TRUE if the operation was successful. * * MT safe. */ gboolean gst_pad_set_active (GstPad * pad, gboolean active) { GstActivateMode old; gboolean ret = FALSE; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); GST_OBJECT_LOCK (pad); old = GST_PAD_ACTIVATE_MODE (pad); GST_OBJECT_UNLOCK (pad); if (active) { switch (old) { case GST_ACTIVATE_PUSH: case GST_ACTIVATE_PULL: ret = TRUE; break; case GST_ACTIVATE_NONE: ret = (GST_PAD_ACTIVATEFUNC (pad)) (pad); break; } } else { switch (old) { case GST_ACTIVATE_PUSH: ret = gst_pad_activate_push (pad, FALSE); break; case GST_ACTIVATE_PULL: ret = gst_pad_activate_pull (pad, FALSE); break; case GST_ACTIVATE_NONE: ret = TRUE; break; } } if (!ret) { GST_OBJECT_LOCK (pad); if (!active) { g_critical ("Failed to deactivate pad %s:%s, very bad", GST_DEBUG_PAD_NAME (pad)); } else { GST_WARNING ("Failed to activate pad %s:%s", GST_DEBUG_PAD_NAME (pad)); } GST_OBJECT_UNLOCK (pad); } return ret; } /** * gst_pad_activate_pull: * @pad: the #GstPad to activate or deactivate. * @active: whether or not the pad should be active. * * Activates or deactivates the given pad in pull mode via dispatching to the * pad's activatepullfunc. For use from within pad activation functions only. * When called on sink pads, will first proxy the call to the peer pad, which is * expected to activate its internally linked pads from within its activate_pull * function. * * If you don't know what this is, you probably don't want to call it. * * Returns: TRUE if the operation was successful. * * MT safe. */ gboolean gst_pad_activate_pull (GstPad * pad, gboolean active) { GstActivateMode old, new; GstPad *peer; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); GST_OBJECT_LOCK (pad); old = GST_PAD_ACTIVATE_MODE (pad); GST_OBJECT_UNLOCK (pad); if (active) { switch (old) { case GST_ACTIVATE_PULL: goto was_ok; case GST_ACTIVATE_PUSH: /* pad was activate in the wrong direction, deactivate it * and reactivate it in pull mode */ if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE))) goto deactivate_failed; /* fallthrough, pad is deactivated now. */ case GST_ACTIVATE_NONE: break; } } else { switch (old) { case GST_ACTIVATE_NONE: goto was_ok; case GST_ACTIVATE_PUSH: /* pad was activated in the other direction, deactivate it * in push mode, this should not happen... */ if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE))) goto deactivate_failed; /* everything is fine now */ goto was_ok; case GST_ACTIVATE_PULL: break; } } if (gst_pad_get_direction (pad) == GST_PAD_SINK) { if ((peer = gst_pad_get_peer (pad))) { if (G_UNLIKELY (!gst_pad_activate_pull (peer, active))) goto peer_failed; gst_object_unref (peer); } else { goto not_linked; } } else { if (G_UNLIKELY (GST_PAD_GETRANGEFUNC (pad) == NULL)) goto failure; /* Can't activate pull on a src without a getrange function */ } new = active ? GST_ACTIVATE_PULL : GST_ACTIVATE_NONE; pre_activate (pad, new); if (GST_PAD_ACTIVATEPULLFUNC (pad)) { if (G_UNLIKELY (!GST_PAD_ACTIVATEPULLFUNC (pad) (pad, active))) goto failure; } else { /* can happen for sinks of passthrough elements */ } post_activate (pad, new); GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in pull mode", active ? "activated" : "deactivated"); return TRUE; was_ok: { GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in pull mode", active ? "activated" : "deactivated"); return TRUE; } deactivate_failed: { GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "failed to %s in switch to pull from mode %d", (active ? "activate" : "deactivate"), old); return FALSE; } peer_failed: { GST_OBJECT_LOCK (peer); GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activate_pull on peer (%s:%s) failed", GST_DEBUG_PAD_NAME (peer)); GST_OBJECT_UNLOCK (peer); gst_object_unref (peer); return FALSE; } not_linked: { GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "can't activate unlinked sink " "pad in pull mode"); return FALSE; } failure: { GST_OBJECT_LOCK (pad); GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in pull mode", active ? "activate" : "deactivate"); GST_PAD_SET_FLUSHING (pad); GST_PAD_ACTIVATE_MODE (pad) = old; GST_OBJECT_UNLOCK (pad); return FALSE; } } /** * gst_pad_activate_push: * @pad: the #GstPad to activate or deactivate. * @active: whether the pad should be active or not. * * Activates or deactivates the given pad in push mode via dispatching to the * pad's activatepushfunc. For use from within pad activation functions only. * * If you don't know what this is, you probably don't want to call it. * * Returns: %TRUE if the operation was successful. * * MT safe. */ gboolean gst_pad_activate_push (GstPad * pad, gboolean active) { GstActivateMode old, new; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "trying to set %s in push mode", active ? "activated" : "deactivated"); GST_OBJECT_LOCK (pad); old = GST_PAD_ACTIVATE_MODE (pad); GST_OBJECT_UNLOCK (pad); if (active) { switch (old) { case GST_ACTIVATE_PUSH: goto was_ok; case GST_ACTIVATE_PULL: /* pad was activate in the wrong direction, deactivate it * an reactivate it in push mode */ if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE))) goto deactivate_failed; /* fallthrough, pad is deactivated now. */ case GST_ACTIVATE_NONE: break; } } else { switch (old) { case GST_ACTIVATE_NONE: goto was_ok; case GST_ACTIVATE_PULL: /* pad was activated in the other direction, deactivate it * in pull mode, this should not happen... */ if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE))) goto deactivate_failed; /* everything is fine now */ goto was_ok; case GST_ACTIVATE_PUSH: break; } } new = active ? GST_ACTIVATE_PUSH : GST_ACTIVATE_NONE; pre_activate (pad, new); if (GST_PAD_ACTIVATEPUSHFUNC (pad)) { if (G_UNLIKELY (!GST_PAD_ACTIVATEPUSHFUNC (pad) (pad, active))) { goto failure; } } else { /* quite ok, element relies on state change func to prepare itself */ } post_activate (pad, new); GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in push mode", active ? "activated" : "deactivated"); return TRUE; was_ok: { GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in push mode", active ? "activated" : "deactivated"); return TRUE; } deactivate_failed: { GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "failed to %s in switch to push from mode %d", (active ? "activate" : "deactivate"), old); return FALSE; } failure: { GST_OBJECT_LOCK (pad); GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in push mode", active ? "activate" : "deactivate"); GST_PAD_SET_FLUSHING (pad); GST_PAD_ACTIVATE_MODE (pad) = old; GST_OBJECT_UNLOCK (pad); return FALSE; } } /** * gst_pad_is_active: * @pad: the #GstPad to query * * Query if a pad is active * * Returns: TRUE if the pad is active. * * MT safe. */ gboolean gst_pad_is_active (GstPad * pad) { gboolean result = FALSE; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); GST_OBJECT_LOCK (pad); result = GST_PAD_MODE_ACTIVATE (GST_PAD_ACTIVATE_MODE (pad)); GST_OBJECT_UNLOCK (pad); return result; } /** * gst_pad_set_blocked_async: * @pad: the #GstPad to block or unblock * @blocked: boolean indicating whether the pad should be blocked or unblocked * @callback: #GstPadBlockCallback that will be called when the * operation succeeds * @user_data: user data passed to the callback * * Blocks or unblocks the dataflow on a pad. The provided callback * is called when the operation succeeds; this happens right before the next * attempt at pushing a buffer on the pad. * * This can take a while as the pad can only become blocked when real dataflow * is happening. * When the pipeline is stalled, for example in PAUSED, this can * take an indeterminate amount of time. * You can pass NULL as the callback to make this call block. Be careful with * this blocking call as it might not return for reasons stated above. * * Returns: TRUE if the pad could be blocked. This function can fail * if wrong parameters were passed or the pad was already in the * requested state. * * MT safe. */ gboolean gst_pad_set_blocked_async (GstPad * pad, gboolean blocked, GstPadBlockCallback callback, gpointer user_data) { gboolean was_blocked = FALSE; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); GST_OBJECT_LOCK (pad); was_blocked = GST_PAD_IS_BLOCKED (pad); if (G_UNLIKELY (was_blocked == blocked)) goto had_right_state; if (blocked) { GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocking pad"); GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKED); pad->block_callback = callback; pad->block_data = user_data; if (!callback) { GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for block"); GST_PAD_BLOCK_WAIT (pad); GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocked"); } } else { GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocking pad"); GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKED); pad->block_callback = callback; pad->block_data = user_data; GST_PAD_BLOCK_BROADCAST (pad); if (!callback) { /* no callback, wait for the unblock to happen */ GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for unblock"); GST_PAD_BLOCK_WAIT (pad); GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocked"); } } GST_OBJECT_UNLOCK (pad); return TRUE; had_right_state: { GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad was in right state (%d)", was_blocked); GST_OBJECT_UNLOCK (pad); return FALSE; } } /** * gst_pad_set_blocked: * @pad: the #GstPad to block or unblock * @blocked: boolean indicating we should block or unblock * * Blocks or unblocks the dataflow on a pad. This function is * a shortcut for gst_pad_set_blocked_async() with a NULL * callback. * * Returns: TRUE if the pad could be blocked. This function can fail * wrong parameters were passed or the pad was already in the * requested state. * * MT safe. */ gboolean gst_pad_set_blocked (GstPad * pad, gboolean blocked) { return gst_pad_set_blocked_async (pad, blocked, NULL, NULL); } /** * gst_pad_is_blocked: * @pad: the #GstPad to query * * Checks if the pad is blocked or not. This function returns the * last requested state of the pad. It is not certain that the pad * is actually blocking at this point (see gst_pad_is_blocking()). * * Returns: TRUE if the pad is blocked. * * MT safe. */ gboolean gst_pad_is_blocked (GstPad * pad) { gboolean result = FALSE; g_return_val_if_fail (GST_IS_PAD (pad), result); GST_OBJECT_LOCK (pad); result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKED); GST_OBJECT_UNLOCK (pad); return result; } /** * gst_pad_is_blocking: * @pad: the #GstPad to query * * Checks if the pad is blocking or not. This is a guaranteed state * of whether the pad is actually blocking on a #GstBuffer or a #GstEvent. * * Returns: TRUE if the pad is blocking. * * MT safe. * * Since: 0.10.11 */ gboolean gst_pad_is_blocking (GstPad * pad) { gboolean result = FALSE; g_return_val_if_fail (GST_IS_PAD (pad), result); GST_OBJECT_LOCK (pad); /* the blocking flag is only valid if the pad is not flushing */ result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKING) && !GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLUSHING); GST_OBJECT_UNLOCK (pad); return result; } /** * gst_pad_set_activate_function: * @pad: a #GstPad. * @activate: the #GstPadActivateFunction to set. * * Sets the given activate function for @pad. The activate function will * dispatch to gst_pad_activate_push() or gst_pad_activate_pull() to perform * the actual activation. Only makes sense to set on sink pads. * * Call this function if your sink pad can start a pull-based task. */ void gst_pad_set_activate_function (GstPad * pad, GstPadActivateFunction activate) { g_return_if_fail (GST_IS_PAD (pad)); GST_PAD_ACTIVATEFUNC (pad) = activate; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatefunc set to %s", GST_DEBUG_FUNCPTR_NAME (activate)); } /** * gst_pad_set_activatepull_function: * @pad: a #GstPad. * @activatepull: the #GstPadActivateModeFunction to set. * * Sets the given activate_pull function for the pad. An activate_pull function * prepares the element and any upstream connections for pulling. See XXX * part-activation.txt for details. */ void gst_pad_set_activatepull_function (GstPad * pad, GstPadActivateModeFunction activatepull) { g_return_if_fail (GST_IS_PAD (pad)); GST_PAD_ACTIVATEPULLFUNC (pad) = activatepull; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepullfunc set to %s", GST_DEBUG_FUNCPTR_NAME (activatepull)); } /** * gst_pad_set_activatepush_function: * @pad: a #GstPad. * @activatepush: the #GstPadActivateModeFunction to set. * * Sets the given activate_push function for the pad. An activate_push function * prepares the element for pushing. See XXX part-activation.txt for details. */ void gst_pad_set_activatepush_function (GstPad * pad, GstPadActivateModeFunction activatepush) { g_return_if_fail (GST_IS_PAD (pad)); GST_PAD_ACTIVATEPUSHFUNC (pad) = activatepush; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepushfunc set to %s", GST_DEBUG_FUNCPTR_NAME (activatepush)); } /** * gst_pad_set_chain_function: * @pad: a sink #GstPad. * @chain: the #GstPadChainFunction to set. * * Sets the given chain function for the pad. The chain function is called to * process a #GstBuffer input buffer. see #GstPadChainFunction for more details. */ void gst_pad_set_chain_function (GstPad * pad, GstPadChainFunction chain) { g_return_if_fail (GST_IS_PAD (pad)); g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK); GST_PAD_CHAINFUNC (pad) = chain; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "chainfunc set to %s", GST_DEBUG_FUNCPTR_NAME (chain)); } /** * gst_pad_set_getrange_function: * @pad: a source #GstPad. * @get: the #GstPadGetRangeFunction to set. * * Sets the given getrange function for the pad. The getrange function is called to * produce a new #GstBuffer to start the processing pipeline. see * #GstPadGetRangeFunction for a description of the getrange function. */ void gst_pad_set_getrange_function (GstPad * pad, GstPadGetRangeFunction get) { g_return_if_fail (GST_IS_PAD (pad)); g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC); GST_PAD_GETRANGEFUNC (pad) = get; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getrangefunc set to %s", GST_DEBUG_FUNCPTR_NAME (get)); } /** * gst_pad_set_checkgetrange_function: * @pad: a source #GstPad. * @check: the #GstPadCheckGetRangeFunction to set. * * Sets the given checkgetrange function for the pad. Implement this function on * a pad if you dynamically support getrange based scheduling on the pad. */ void gst_pad_set_checkgetrange_function (GstPad * pad, GstPadCheckGetRangeFunction check) { g_return_if_fail (GST_IS_PAD (pad)); g_return_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC); GST_PAD_CHECKGETRANGEFUNC (pad) = check; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "checkgetrangefunc set to %s", GST_DEBUG_FUNCPTR_NAME (check)); } /** * gst_pad_set_event_function: * @pad: a source #GstPad. * @event: the #GstPadEventFunction to set. * * Sets the given event handler for the pad. */ void gst_pad_set_event_function (GstPad * pad, GstPadEventFunction event) { g_return_if_fail (GST_IS_PAD (pad)); GST_PAD_EVENTFUNC (pad) = event; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "eventfunc for set to %s", GST_DEBUG_FUNCPTR_NAME (event)); } /** * gst_pad_set_query_function: * @pad: a #GstPad of either direction. * @query: the #GstPadQueryFunction to set. * * Set the given query function for the pad. */ void gst_pad_set_query_function (GstPad * pad, GstPadQueryFunction query) { g_return_if_fail (GST_IS_PAD (pad)); GST_PAD_QUERYFUNC (pad) = query; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "queryfunc set to %s", GST_DEBUG_FUNCPTR_NAME (query)); } /** * gst_pad_set_query_type_function: * @pad: a #GstPad of either direction. * @type_func: the #GstPadQueryTypeFunction to set. * * Set the given query type function for the pad. */ void gst_pad_set_query_type_function (GstPad * pad, GstPadQueryTypeFunction type_func) { g_return_if_fail (GST_IS_PAD (pad)); GST_PAD_QUERYTYPEFUNC (pad) = type_func; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "querytypefunc set to %s", GST_DEBUG_FUNCPTR_NAME (type_func)); } /** * gst_pad_get_query_types: * @pad: a #GstPad. * * Get an array of supported queries that can be performed * on this pad. * * Returns: a zero-terminated array of #GstQueryType. */ const GstQueryType * gst_pad_get_query_types (GstPad * pad) { GstPadQueryTypeFunction func; g_return_val_if_fail (GST_IS_PAD (pad), NULL); if (G_UNLIKELY ((func = GST_PAD_QUERYTYPEFUNC (pad)) == NULL)) goto no_func; return func (pad); no_func: { return NULL; } } static gboolean gst_pad_get_query_types_dispatcher (GstPad * pad, const GstQueryType ** data) { *data = gst_pad_get_query_types (pad); return TRUE; } /** * gst_pad_get_query_types_default: * @pad: a #GstPad. * * Invoke the default dispatcher for the query types on * the pad. * * Returns: an zero-terminated array of #GstQueryType, or NULL if none of the * internally-linked pads has a query types function. */ const GstQueryType * gst_pad_get_query_types_default (GstPad * pad) { GstQueryType *result = NULL; g_return_val_if_fail (GST_IS_PAD (pad), NULL); gst_pad_dispatcher (pad, (GstPadDispatcherFunction) gst_pad_get_query_types_dispatcher, &result); return result; } /** * gst_pad_set_internal_link_function: * @pad: a #GstPad of either direction. * @intlink: the #GstPadIntLinkFunction to set. * * Sets the given internal link function for the pad. */ void gst_pad_set_internal_link_function (GstPad * pad, GstPadIntLinkFunction intlink) { g_return_if_fail (GST_IS_PAD (pad)); GST_PAD_INTLINKFUNC (pad) = intlink; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "internal link set to %s", GST_DEBUG_FUNCPTR_NAME (intlink)); } /** * gst_pad_set_link_function: * @pad: a #GstPad. * @link: the #GstPadLinkFunction to set. * * Sets the given link function for the pad. It will be called when * the pad is linked with another pad. * * The return value #GST_PAD_LINK_OK should be used when the connection can be * made. * * The return value #GST_PAD_LINK_REFUSED should be used when the connection * cannot be made for some reason. * * If @link is installed on a source pad, it should call the #GstPadLinkFunction * of the peer sink pad, if present. */ void gst_pad_set_link_function (GstPad * pad, GstPadLinkFunction link) { g_return_if_fail (GST_IS_PAD (pad)); GST_PAD_LINKFUNC (pad) = link; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "linkfunc set to %s", GST_DEBUG_FUNCPTR_NAME (link)); } /** * gst_pad_set_unlink_function: * @pad: a #GstPad. * @unlink: the #GstPadUnlinkFunction to set. * * Sets the given unlink function for the pad. It will be called * when the pad is unlinked. */ void gst_pad_set_unlink_function (GstPad * pad, GstPadUnlinkFunction unlink) { g_return_if_fail (GST_IS_PAD (pad)); GST_PAD_UNLINKFUNC (pad) = unlink; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "unlinkfunc set to %s", GST_DEBUG_FUNCPTR_NAME (unlink)); } /** * gst_pad_set_getcaps_function: * @pad: a #GstPad. * @getcaps: the #GstPadGetCapsFunction to set. * * Sets the given getcaps function for the pad. @getcaps should return the * allowable caps for a pad in the context of the element's state, its link to * other elements, and the devices or files it has opened. These caps must be a * subset of the pad template caps. In the NULL state with no links, @getcaps * should ideally return the same caps as the pad template. In rare * circumstances, an object property can affect the caps returned by @getcaps, * but this is discouraged. * * You do not need to call this function if @pad's allowed caps are always the * same as the pad template caps. This can only be true if the padtemplate * has fixed simple caps. * * For most filters, the caps returned by @getcaps is directly affected by the * allowed caps on other pads. For demuxers and decoders, the caps returned by * the srcpad's getcaps function is directly related to the stream data. Again, * @getcaps should return the most specific caps it reasonably can, since this * helps with autoplugging. * * Note that the return value from @getcaps is owned by the caller, so the caller * should unref the caps after usage. */ void gst_pad_set_getcaps_function (GstPad * pad, GstPadGetCapsFunction getcaps) { g_return_if_fail (GST_IS_PAD (pad)); GST_PAD_GETCAPSFUNC (pad) = getcaps; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getcapsfunc set to %s", GST_DEBUG_FUNCPTR_NAME (getcaps)); } /** * gst_pad_set_acceptcaps_function: * @pad: a #GstPad. * @acceptcaps: the #GstPadAcceptCapsFunction to set. * * Sets the given acceptcaps function for the pad. The acceptcaps function * will be called to check if the pad can accept the given caps. Setting the * acceptcaps function to NULL restores the default behaviour of allowing * any caps that matches the caps from gst_pad_get_caps. */ void gst_pad_set_acceptcaps_function (GstPad * pad, GstPadAcceptCapsFunction acceptcaps) { g_return_if_fail (GST_IS_PAD (pad)); GST_PAD_ACCEPTCAPSFUNC (pad) = acceptcaps; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "acceptcapsfunc set to %s", GST_DEBUG_FUNCPTR_NAME (acceptcaps)); } /** * gst_pad_set_fixatecaps_function: * @pad: a #GstPad. * @fixatecaps: the #GstPadFixateCapsFunction to set. * * Sets the given fixatecaps function for the pad. The fixatecaps function * will be called whenever the default values for a GstCaps needs to be * filled in. */ void gst_pad_set_fixatecaps_function (GstPad * pad, GstPadFixateCapsFunction fixatecaps) { g_return_if_fail (GST_IS_PAD (pad)); GST_PAD_FIXATECAPSFUNC (pad) = fixatecaps; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fixatecapsfunc set to %s", GST_DEBUG_FUNCPTR_NAME (fixatecaps)); } /** * gst_pad_set_setcaps_function: * @pad: a #GstPad. * @setcaps: the #GstPadSetCapsFunction to set. * * Sets the given setcaps function for the pad. The setcaps function * will be called whenever a buffer with a new media type is pushed or * pulled from the pad. The pad/element needs to update its internal * structures to process the new media type. If this new type is not * acceptable, the setcaps function should return FALSE. */ void gst_pad_set_setcaps_function (GstPad * pad, GstPadSetCapsFunction setcaps) { g_return_if_fail (GST_IS_PAD (pad)); GST_PAD_SETCAPSFUNC (pad) = setcaps; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "setcapsfunc set to %s", GST_DEBUG_FUNCPTR_NAME (setcaps)); } /** * gst_pad_set_bufferalloc_function: * @pad: a sink #GstPad. * @bufalloc: the #GstPadBufferAllocFunction to set. * * Sets the given bufferalloc function for the pad. Note that the * bufferalloc function can only be set on sinkpads. */ void gst_pad_set_bufferalloc_function (GstPad * pad, GstPadBufferAllocFunction bufalloc) { g_return_if_fail (GST_IS_PAD (pad)); g_return_if_fail (GST_PAD_IS_SINK (pad)); GST_PAD_BUFFERALLOCFUNC (pad) = bufalloc; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "bufferallocfunc set to %s", GST_DEBUG_FUNCPTR_NAME (bufalloc)); } /** * gst_pad_unlink: * @srcpad: the source #GstPad to unlink. * @sinkpad: the sink #GstPad to unlink. * * Unlinks the source pad from the sink pad. Will emit the "unlinked" signal on * both pads. * * Returns: TRUE if the pads were unlinked. This function returns FALSE if * the pads were not linked together. * * MT safe. */ gboolean gst_pad_unlink (GstPad * srcpad, GstPad * sinkpad) { g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE); g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE); GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinking %s:%s(%p) and %s:%s(%p)", GST_DEBUG_PAD_NAME (srcpad), srcpad, GST_DEBUG_PAD_NAME (sinkpad), sinkpad); GST_OBJECT_LOCK (srcpad); if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC)) goto not_srcpad; GST_OBJECT_LOCK (sinkpad); if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK)) goto not_sinkpad; if (G_UNLIKELY (GST_PAD_PEER (srcpad) != sinkpad)) goto not_linked_together; if (GST_PAD_UNLINKFUNC (srcpad)) { GST_PAD_UNLINKFUNC (srcpad) (srcpad); } if (GST_PAD_UNLINKFUNC (sinkpad)) { GST_PAD_UNLINKFUNC (sinkpad) (sinkpad); } /* first clear peers */ GST_PAD_PEER (srcpad) = NULL; GST_PAD_PEER (sinkpad) = NULL; GST_OBJECT_UNLOCK (sinkpad); GST_OBJECT_UNLOCK (srcpad); /* fire off a signal to each of the pads telling them * that they've been unlinked */ g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_UNLINKED], 0, sinkpad); g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_UNLINKED], 0, srcpad); GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinked %s:%s and %s:%s", GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad)); return TRUE; not_srcpad: { g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad)); GST_OBJECT_UNLOCK (srcpad); return FALSE; } not_sinkpad: { g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad)); GST_OBJECT_UNLOCK (sinkpad); GST_OBJECT_UNLOCK (srcpad); return FALSE; } not_linked_together: { /* we do not emit a warning in this case because unlinking cannot * be made MT safe.*/ GST_OBJECT_UNLOCK (sinkpad); GST_OBJECT_UNLOCK (srcpad); return FALSE; } } /** * gst_pad_is_linked: * @pad: pad to check * * Checks if a @pad is linked to another pad or not. * * Returns: TRUE if the pad is linked, FALSE otherwise. * * MT safe. */ gboolean gst_pad_is_linked (GstPad * pad) { gboolean result; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); GST_OBJECT_LOCK (pad); result = (GST_PAD_PEER (pad) != NULL); GST_OBJECT_UNLOCK (pad); return result; } /* get the caps from both pads and see if the intersection * is not empty. * * This function should be called with the pad LOCK on both * pads */ static gboolean gst_pad_link_check_compatible_unlocked (GstPad * src, GstPad * sink) { GstCaps *srccaps; GstCaps *sinkcaps; GstCaps *icaps; srccaps = gst_pad_get_caps_unlocked (src); sinkcaps = gst_pad_get_caps_unlocked (sink); GST_CAT_DEBUG (GST_CAT_CAPS, "src caps %" GST_PTR_FORMAT, srccaps); GST_CAT_DEBUG (GST_CAT_CAPS, "sink caps %" GST_PTR_FORMAT, sinkcaps); /* if we have caps on both pads we can check the intersection. If one * of the caps is NULL, we return TRUE. */ if (srccaps == NULL || sinkcaps == NULL) goto done; icaps = gst_caps_intersect (srccaps, sinkcaps); gst_caps_unref (srccaps); gst_caps_unref (sinkcaps); if (icaps == NULL) goto was_null; GST_CAT_DEBUG (GST_CAT_CAPS, "intersection caps %p %" GST_PTR_FORMAT, icaps, icaps); if (gst_caps_is_empty (icaps)) goto was_empty; gst_caps_unref (icaps); done: return TRUE; /* incompatible cases */ was_null: { GST_CAT_DEBUG (GST_CAT_CAPS, "intersection gave NULL"); return FALSE; } was_empty: { GST_CAT_DEBUG (GST_CAT_CAPS, "intersection is EMPTY"); gst_caps_unref (icaps); return FALSE; } } /* check if the grandparents of both pads are the same. * This check is required so that we don't try to link * pads from elements in different bins without ghostpads. * * The LOCK should be held on both pads */ static gboolean gst_pad_link_check_hierarchy (GstPad * src, GstPad * sink) { GstObject *psrc, *psink; psrc = GST_OBJECT_PARENT (src); psink = GST_OBJECT_PARENT (sink); /* if one of the pads has no parent, we allow the link */ if (G_UNLIKELY (psrc == NULL || psink == NULL)) goto no_parent; /* if the parents are the same, we have a loop */ if (G_UNLIKELY (psrc == psink)) goto same_parents; /* if they both have a parent, we check the grandparents. We can not lock * the parent because we hold on the child (pad) and the locking order is * parent >> child. */ psrc = GST_OBJECT_PARENT (psrc); psink = GST_OBJECT_PARENT (psink); /* if they have grandparents but they are not the same */ if (G_UNLIKELY (psrc != psink)) goto wrong_grandparents; return TRUE; /* ERRORS */ no_parent: { GST_CAT_DEBUG (GST_CAT_CAPS, "one of the pads has no parent %" GST_PTR_FORMAT " and %" GST_PTR_FORMAT, psrc, psink); return TRUE; } same_parents: { GST_CAT_DEBUG (GST_CAT_CAPS, "pads have same parent %" GST_PTR_FORMAT, psrc); return FALSE; } wrong_grandparents: { GST_CAT_DEBUG (GST_CAT_CAPS, "pads have different grandparents %" GST_PTR_FORMAT " and %" GST_PTR_FORMAT, psrc, psink); return FALSE; } } /* FIXME leftover from an attempt at refactoring... */ /* call with the two pads unlocked, when this function returns GST_PAD_LINK_OK, * the two pads will be locked in the srcpad, sinkpad order. */ static GstPadLinkReturn gst_pad_link_prepare (GstPad * srcpad, GstPad * sinkpad) { /* generic checks */ g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED); g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED); GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s", GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad)); GST_OBJECT_LOCK (srcpad); if (G_UNLIKELY (GST_PAD_DIRECTION (srcpad) != GST_PAD_SRC)) goto not_srcpad; if (G_UNLIKELY (GST_PAD_PEER (srcpad) != NULL)) goto src_was_linked; GST_OBJECT_LOCK (sinkpad); if (G_UNLIKELY (GST_PAD_DIRECTION (sinkpad) != GST_PAD_SINK)) goto not_sinkpad; if (G_UNLIKELY (GST_PAD_PEER (sinkpad) != NULL)) goto sink_was_linked; /* check hierarchy, pads can only be linked if the grandparents * are the same. */ if (!gst_pad_link_check_hierarchy (srcpad, sinkpad)) goto wrong_hierarchy; /* check pad caps for non-empty intersection */ if (!gst_pad_link_check_compatible_unlocked (srcpad, sinkpad)) goto no_format; /* FIXME check pad scheduling for non-empty intersection */ return GST_PAD_LINK_OK; not_srcpad: { g_critical ("pad %s is not a source pad", GST_PAD_NAME (srcpad)); GST_OBJECT_UNLOCK (srcpad); return GST_PAD_LINK_WRONG_DIRECTION; } src_was_linked: { GST_CAT_INFO (GST_CAT_PADS, "src %s:%s was already linked to %s:%s", GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad))); /* we do not emit a warning in this case because unlinking cannot * be made MT safe.*/ GST_OBJECT_UNLOCK (srcpad); return GST_PAD_LINK_WAS_LINKED; } not_sinkpad: { g_critical ("pad %s is not a sink pad", GST_PAD_NAME (sinkpad)); GST_OBJECT_UNLOCK (sinkpad); GST_OBJECT_UNLOCK (srcpad); return GST_PAD_LINK_WRONG_DIRECTION; } sink_was_linked: { GST_CAT_INFO (GST_CAT_PADS, "sink %s:%s was already linked to %s:%s", GST_DEBUG_PAD_NAME (sinkpad), GST_DEBUG_PAD_NAME (GST_PAD_PEER (sinkpad))); /* we do not emit a warning in this case because unlinking cannot * be made MT safe.*/ GST_OBJECT_UNLOCK (sinkpad); GST_OBJECT_UNLOCK (srcpad); return GST_PAD_LINK_WAS_LINKED; } wrong_hierarchy: { GST_CAT_INFO (GST_CAT_PADS, "pads have wrong hierarchy"); GST_OBJECT_UNLOCK (sinkpad); GST_OBJECT_UNLOCK (srcpad); return GST_PAD_LINK_WRONG_HIERARCHY; } no_format: { GST_CAT_INFO (GST_CAT_PADS, "caps are incompatible"); GST_OBJECT_UNLOCK (sinkpad); GST_OBJECT_UNLOCK (srcpad); return GST_PAD_LINK_NOFORMAT; } } /** * gst_pad_link: * @srcpad: the source #GstPad to link. * @sinkpad: the sink #GstPad to link. * * Links the source pad and the sink pad. * * Returns: A result code indicating if the connection worked or * what went wrong. * * MT Safe. */ GstPadLinkReturn gst_pad_link (GstPad * srcpad, GstPad * sinkpad) { GstPadLinkReturn result; /* prepare will also lock the two pads */ result = gst_pad_link_prepare (srcpad, sinkpad); if (result != GST_PAD_LINK_OK) goto prepare_failed; /* must set peers before calling the link function */ GST_PAD_PEER (srcpad) = sinkpad; GST_PAD_PEER (sinkpad) = srcpad; GST_OBJECT_UNLOCK (sinkpad); GST_OBJECT_UNLOCK (srcpad); /* FIXME released the locks here, concurrent thread might link * something else. */ if (GST_PAD_LINKFUNC (srcpad)) { /* this one will call the peer link function */ result = GST_PAD_LINKFUNC (srcpad) (srcpad, sinkpad); } else if (GST_PAD_LINKFUNC (sinkpad)) { /* if no source link function, we need to call the sink link * function ourselves. */ result = GST_PAD_LINKFUNC (sinkpad) (sinkpad, srcpad); } else { result = GST_PAD_LINK_OK; } GST_OBJECT_LOCK (srcpad); GST_OBJECT_LOCK (sinkpad); if (result == GST_PAD_LINK_OK) { GST_OBJECT_UNLOCK (sinkpad); GST_OBJECT_UNLOCK (srcpad); /* fire off a signal to each of the pads telling them * that they've been linked */ g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_LINKED], 0, sinkpad); g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_LINKED], 0, srcpad); GST_CAT_INFO (GST_CAT_PADS, "linked %s:%s and %s:%s, successful", GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad)); } else { GST_CAT_INFO (GST_CAT_PADS, "link between %s:%s and %s:%s failed", GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad)); GST_PAD_PEER (srcpad) = NULL; GST_PAD_PEER (sinkpad) = NULL; GST_OBJECT_UNLOCK (sinkpad); GST_OBJECT_UNLOCK (srcpad); } return result; prepare_failed: { return result; } } static void gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ) { GstPadTemplate **template_p; /* this function would need checks if it weren't static */ GST_OBJECT_LOCK (pad); template_p = &pad->padtemplate; gst_object_replace ((GstObject **) template_p, (GstObject *) templ); GST_OBJECT_UNLOCK (pad); if (templ) gst_pad_template_pad_created (templ, pad); } /** * gst_pad_get_pad_template: * @pad: a #GstPad. * * Gets the template for @pad. * * Returns: the #GstPadTemplate from which this pad was instantiated, or %NULL * if this pad has no template. * * FIXME: currently returns an unrefcounted padtemplate. */ GstPadTemplate * gst_pad_get_pad_template (GstPad * pad) { g_return_val_if_fail (GST_IS_PAD (pad), NULL); return GST_PAD_PAD_TEMPLATE (pad); } /* should be called with the pad LOCK held */ /* refs the caps, so caller is responsible for getting it unreffed */ static GstCaps * gst_pad_get_caps_unlocked (GstPad * pad) { GstCaps *result = NULL; GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps"); if (GST_PAD_GETCAPSFUNC (pad)) { GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "dispatching to pad getcaps function"); GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS); GST_OBJECT_UNLOCK (pad); result = GST_PAD_GETCAPSFUNC (pad) (pad); GST_OBJECT_LOCK (pad); GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS); if (result == NULL) { g_critical ("pad %s:%s returned NULL caps from getcaps function", GST_DEBUG_PAD_NAME (pad)); } else { GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad getcaps returned %" GST_PTR_FORMAT, result); #ifndef G_DISABLE_ASSERT /* check that the returned caps are a real subset of the template caps */ if (GST_PAD_PAD_TEMPLATE (pad)) { const GstCaps *templ_caps = GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad)); if (!gst_caps_is_subset (result, templ_caps)) { GstCaps *temp; GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad, "pad returned caps %" GST_PTR_FORMAT " which are not a real subset of its template caps %" GST_PTR_FORMAT, result, templ_caps); g_warning ("pad %s:%s returned caps which are not a real " "subset of its template caps", GST_DEBUG_PAD_NAME (pad)); temp = gst_caps_intersect (templ_caps, result); gst_caps_unref (result); result = temp; } } #endif goto done; } } if (GST_PAD_PAD_TEMPLATE (pad)) { GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad); result = GST_PAD_TEMPLATE_CAPS (templ); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result, result); result = gst_caps_ref (result); goto done; } if (GST_PAD_CAPS (pad)) { result = GST_PAD_CAPS (pad); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "using pad caps %p %" GST_PTR_FORMAT, result, result); result = gst_caps_ref (result); goto done; } GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad has no caps"); result = gst_caps_new_empty (); done: return result; } /** * gst_pad_get_caps: * @pad: a #GstPad to get the capabilities of. * * Gets the capabilities this pad can produce or consume. * Note that this method doesn't necessarily return the caps set by * gst_pad_set_caps() - use #GST_PAD_CAPS for that instead. * gst_pad_get_caps returns all possible caps a pad can operate with, using * the pad's get_caps function; * this returns the pad template caps if not explicitly set. * * Returns: a newly allocated copy of the #GstCaps of this pad. * * MT safe. */ GstCaps * gst_pad_get_caps (GstPad * pad) { GstCaps *result = NULL; g_return_val_if_fail (GST_IS_PAD (pad), NULL); GST_OBJECT_LOCK (pad); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps"); result = gst_pad_get_caps_unlocked (pad); GST_OBJECT_UNLOCK (pad); return result; } /** * gst_pad_peer_get_caps: * @pad: a #GstPad to get the peer capabilities of. * * Gets the capabilities of the peer connected to this pad. * * Returns: the #GstCaps of the peer pad. This function returns a new caps, so use * gst_caps_unref to get rid of it. this function returns NULL if there is no * peer pad. */ GstCaps * gst_pad_peer_get_caps (GstPad * pad) { GstPad *peerpad; GstCaps *result = NULL; g_return_val_if_fail (GST_IS_PAD (pad), NULL); GST_OBJECT_LOCK (pad); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get peer caps"); peerpad = GST_PAD_PEER (pad); if (G_UNLIKELY (peerpad == NULL)) goto no_peer; gst_object_ref (peerpad); GST_OBJECT_UNLOCK (pad); result = gst_pad_get_caps (peerpad); gst_object_unref (peerpad); return result; no_peer: { GST_OBJECT_UNLOCK (pad); return NULL; } } static gboolean fixate_value (GValue * dest, const GValue * src) { if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) { g_value_init (dest, G_TYPE_INT); g_value_set_int (dest, gst_value_get_int_range_min (src)); } else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) { g_value_init (dest, G_TYPE_DOUBLE); g_value_set_double (dest, gst_value_get_double_range_min (src)); } else if (G_VALUE_TYPE (src) == GST_TYPE_FRACTION_RANGE) { gst_value_init_and_copy (dest, gst_value_get_fraction_range_min (src)); } else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) { GValue temp = { 0 }; gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0)); if (!fixate_value (dest, &temp)) gst_value_init_and_copy (dest, &temp); g_value_unset (&temp); } else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) { gboolean res = FALSE; guint n; g_value_init (dest, GST_TYPE_ARRAY); for (n = 0; n < gst_value_array_get_size (src); n++) { GValue kid = { 0 }; const GValue *orig_kid = gst_value_array_get_value (src, n); if (!fixate_value (&kid, orig_kid)) gst_value_init_and_copy (&kid, orig_kid); else res = TRUE; gst_value_array_append_value (dest, &kid); g_value_unset (&kid); } if (!res) g_value_unset (dest); return res; } else { return FALSE; } return TRUE; } static gboolean gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data) { GstStructure *s = data; GValue v = { 0 }; if (fixate_value (&v, value)) { gst_structure_id_set_value (s, field_id, &v); g_value_unset (&v); } return TRUE; } /** * gst_pad_fixate_caps: * @pad: a #GstPad to fixate * @caps: the #GstCaps to fixate * * Fixate a caps on the given pad. Modifies the caps in place, so you should * make sure that the caps are actually writable (see gst_caps_make_writable()). */ void gst_pad_fixate_caps (GstPad * pad, GstCaps * caps) { GstPadFixateCapsFunction fixatefunc; guint n; g_return_if_fail (GST_IS_PAD (pad)); g_return_if_fail (caps != NULL); if (gst_caps_is_fixed (caps)) return; fixatefunc = GST_PAD_FIXATECAPSFUNC (pad); if (fixatefunc) { fixatefunc (pad, caps); } /* default fixation */ for (n = 0; n < gst_caps_get_size (caps); n++) { GstStructure *s = gst_caps_get_structure (caps, n); gst_structure_foreach (s, gst_pad_default_fixate, s); } } /* Default accept caps implementation just checks against * against the allowed caps for the pad */ static gboolean gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps) { /* get the caps and see if it intersects to something * not empty */ GstCaps *intersect; GstCaps *allowed; gboolean result = FALSE; allowed = gst_pad_get_caps (pad); if (!allowed) goto nothing_allowed; intersect = gst_caps_intersect (allowed, caps); result = !gst_caps_is_empty (intersect); if (!result) GST_DEBUG_OBJECT (pad, "intersection gave empty caps"); gst_caps_unref (allowed); gst_caps_unref (intersect); return result; /* ERRORS */ nothing_allowed: { GST_DEBUG_OBJECT (pad, "no caps allowed on the pad"); return FALSE; } } /** * gst_pad_accept_caps: * @pad: a #GstPad to check * @caps: a #GstCaps to check on the pad * * Check if the given pad accepts the caps. * * Returns: TRUE if the pad can accept the caps. */ gboolean gst_pad_accept_caps (GstPad * pad, GstCaps * caps) { gboolean result; GstPadAcceptCapsFunction acceptfunc; GstCaps *existing = NULL; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); /* any pad can be unnegotiated */ if (caps == NULL) return TRUE; /* lock for checking the existing caps */ GST_OBJECT_LOCK (pad); acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %p", caps); /* The current caps on a pad are trivially acceptable */ if (G_LIKELY ((existing = GST_PAD_CAPS (pad)))) { if (caps == existing || gst_caps_is_equal (caps, existing)) goto is_same_caps; } GST_OBJECT_UNLOCK (pad); if (G_LIKELY (acceptfunc)) { /* we can call the function */ result = acceptfunc (pad, caps); GST_DEBUG_OBJECT (pad, "acceptfunc returned %d", result); } else { /* Only null if the element explicitly unset it */ result = gst_pad_acceptcaps_default (pad, caps); GST_DEBUG_OBJECT (pad, "default acceptcaps returned %d", result); } return result; is_same_caps: { GST_DEBUG_OBJECT (pad, "pad had same caps"); GST_OBJECT_UNLOCK (pad); return TRUE; } } /** * gst_pad_peer_accept_caps: * @pad: a #GstPad to check the peer of * @caps: a #GstCaps to check on the pad * * Check if the peer of @pad accepts @caps. If @pad has no peer, this function * returns TRUE. * * Returns: TRUE if the peer of @pad can accept the caps or @pad has no peer. */ gboolean gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps) { GstPad *peerpad; gboolean result; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); GST_OBJECT_LOCK (pad); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "peer accept caps of (%p)", pad); peerpad = GST_PAD_PEER (pad); if (G_UNLIKELY (peerpad == NULL)) goto no_peer; result = gst_pad_accept_caps (peerpad, caps); GST_OBJECT_UNLOCK (pad); return result; no_peer: { GST_OBJECT_UNLOCK (pad); return TRUE; } } /** * gst_pad_set_caps: * @pad: a #GstPad to set the capabilities of. * @caps: a #GstCaps to set. * * Sets the capabilities of this pad. The caps must be fixed. Any previous * caps on the pad will be unreffed. This function refs the caps so you should * unref if as soon as you don't need it anymore. * It is possible to set NULL caps, which will make the pad unnegotiated * again. * * Returns: TRUE if the caps could be set. FALSE if the caps were not fixed * or bad parameters were provided to this function. * * MT safe. */ gboolean gst_pad_set_caps (GstPad * pad, GstCaps * caps) { GstPadSetCapsFunction setcaps; GstCaps *existing; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE); GST_OBJECT_LOCK (pad); existing = GST_PAD_CAPS (pad); if (existing == caps) goto was_ok; if (gst_caps_is_equal (caps, existing)) goto setting_same_caps; setcaps = GST_PAD_SETCAPSFUNC (pad); /* call setcaps function to configure the pad only if the * caps is not NULL */ if (setcaps != NULL && caps) { if (!GST_PAD_IS_IN_SETCAPS (pad)) { GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_SETCAPS); GST_OBJECT_UNLOCK (pad); if (!setcaps (pad, caps)) goto could_not_set; GST_OBJECT_LOCK (pad); GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS); } else { GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad was dispatching"); } } gst_caps_replace (&GST_PAD_CAPS (pad), caps); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "caps %" GST_PTR_FORMAT, caps); GST_OBJECT_UNLOCK (pad); g_object_notify (G_OBJECT (pad), "caps"); return TRUE; was_ok: { GST_OBJECT_UNLOCK (pad); return TRUE; } setting_same_caps: { gst_caps_replace (&GST_PAD_CAPS (pad), caps); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps); GST_OBJECT_UNLOCK (pad); return TRUE; } /* ERRORS */ could_not_set: { GST_OBJECT_LOCK (pad); GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "caps %" GST_PTR_FORMAT " could not be set", caps); GST_OBJECT_UNLOCK (pad); return FALSE; } } static gboolean gst_pad_configure_sink (GstPad * pad, GstCaps * caps) { GstPadSetCapsFunction setcaps; gboolean res; setcaps = GST_PAD_SETCAPSFUNC (pad); /* See if pad accepts the caps - only needed if * no setcaps function */ if (setcaps == NULL) if (!gst_pad_accept_caps (pad, caps)) goto not_accepted; /* set caps on pad if call succeeds */ res = gst_pad_set_caps (pad, caps); /* no need to unref the caps here, set_caps takes a ref and * our ref goes away when we leave this function. */ return res; not_accepted: { GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "caps %" GST_PTR_FORMAT " not accepted", caps); return FALSE; } } /* returns TRUE if the src pad could be configured to accept the given caps */ static gboolean gst_pad_configure_src (GstPad * pad, GstCaps * caps, gboolean dosetcaps) { GstPadSetCapsFunction setcaps; gboolean res; setcaps = GST_PAD_SETCAPSFUNC (pad); /* See if pad accepts the caps - only needed if * no setcaps function */ if (setcaps == NULL) if (!gst_pad_accept_caps (pad, caps)) goto not_accepted; if (dosetcaps) res = gst_pad_set_caps (pad, caps); else res = TRUE; return res; not_accepted: { GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "caps %" GST_PTR_FORMAT " not accepted", caps); return FALSE; } } /** * gst_pad_get_pad_template_caps: * @pad: a #GstPad to get the template capabilities from. * * Gets the capabilities for @pad's template. * * Returns: the #GstCaps of this pad template. If you intend to keep a reference * on the caps, make a copy (see gst_caps_copy ()). */ const GstCaps * gst_pad_get_pad_template_caps (GstPad * pad) { static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY"); g_return_val_if_fail (GST_IS_PAD (pad), NULL); if (GST_PAD_PAD_TEMPLATE (pad)) return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad)); return gst_static_caps_get (&anycaps); } /** * gst_pad_get_peer: * @pad: a #GstPad to get the peer of. * * Gets the peer of @pad. This function refs the peer pad so * you need to unref it after use. * * Returns: the peer #GstPad. Unref after usage. * * MT safe. */ GstPad * gst_pad_get_peer (GstPad * pad) { GstPad *result; g_return_val_if_fail (GST_IS_PAD (pad), NULL); GST_OBJECT_LOCK (pad); result = GST_PAD_PEER (pad); if (result) gst_object_ref (result); GST_OBJECT_UNLOCK (pad); return result; } /** * gst_pad_get_allowed_caps: * @pad: a #GstPad. * * Gets the capabilities of the allowed media types that can flow through * @pad and its peer. * * The allowed capabilities is calculated as the intersection of the results of * calling gst_pad_get_caps() on @pad and its peer. The caller owns a reference * on the resulting caps. * * Returns: the allowed #GstCaps of the pad link. Unref the caps when you no * longer need it. This function returns NULL when @pad has no peer. * * MT safe. */ GstCaps * gst_pad_get_allowed_caps (GstPad * pad) { GstCaps *mycaps; GstCaps *caps; GstCaps *peercaps; GstPad *peer; g_return_val_if_fail (GST_IS_PAD (pad), NULL); GST_OBJECT_LOCK (pad); peer = GST_PAD_PEER (pad); if (G_UNLIKELY (peer == NULL)) goto no_peer; GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting allowed caps"); gst_object_ref (peer); GST_OBJECT_UNLOCK (pad); mycaps = gst_pad_get_caps (pad); peercaps = gst_pad_get_caps (peer); gst_object_unref (peer); caps = gst_caps_intersect (mycaps, peercaps); gst_caps_unref (peercaps); gst_caps_unref (mycaps); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "allowed caps %" GST_PTR_FORMAT, caps); return caps; no_peer: { GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer"); GST_OBJECT_UNLOCK (pad); return NULL; } } /** * gst_pad_get_negotiated_caps: * @pad: a #GstPad. * * Gets the capabilities of the media type that currently flows through @pad * and its peer. * * This function can be used on both src and sinkpads. Note that srcpads are * always negotiated before sinkpads so it is possible that the negotiated caps * on the srcpad do not match the negotiated caps of the peer. * * Returns: the negotiated #GstCaps of the pad link. Free the caps when * you no longer need it. This function returns NULL when the @pad has no * peer or is not negotiated yet. * * MT safe. */ GstCaps * gst_pad_get_negotiated_caps (GstPad * pad) { GstCaps *caps; GstPad *peer; g_return_val_if_fail (GST_IS_PAD (pad), NULL); GST_OBJECT_LOCK (pad); if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL)) goto no_peer; GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting negotiated caps"); caps = GST_PAD_CAPS (pad); if (caps) gst_caps_ref (caps); GST_OBJECT_UNLOCK (pad); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "negotiated caps %" GST_PTR_FORMAT, caps); return caps; no_peer: { GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer"); GST_OBJECT_UNLOCK (pad); return NULL; } } /* calls the buffer_alloc function on the given pad */ static GstFlowReturn gst_pad_buffer_alloc_unchecked (GstPad * pad, guint64 offset, gint size, GstCaps * caps, GstBuffer ** buf) { GstFlowReturn ret; GstPadBufferAllocFunction bufferallocfunc; GST_OBJECT_LOCK (pad); /* when the pad is flushing we cannot give a buffer */ if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad))) goto flushing; bufferallocfunc = pad->bufferallocfunc; if (offset == GST_BUFFER_OFFSET_NONE) { GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "calling bufferallocfunc &%s (@%p) for size %d offset NONE", GST_DEBUG_FUNCPTR_NAME (bufferallocfunc), bufferallocfunc, size); } else { GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "calling bufferallocfunc &%s (@%p) of for size %d offset %" G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc), bufferallocfunc, size, offset); } GST_OBJECT_UNLOCK (pad); /* G_LIKELY for now since most elements don't implement a buffer alloc * function and there is no default alloc proxy function as this is usually * not possible. */ if (G_LIKELY (bufferallocfunc == NULL)) goto fallback; ret = bufferallocfunc (pad, offset, size, caps, buf); if (G_UNLIKELY (ret != GST_FLOW_OK)) goto error; /* no error, but NULL buffer means fallback to the default */ if (G_UNLIKELY (*buf == NULL)) goto fallback; /* If the buffer alloc function didn't set up the caps like it should, * do it for it */ if (G_UNLIKELY (caps && (GST_BUFFER_CAPS (*buf) == NULL))) { GST_WARNING_OBJECT (pad, "Buffer allocation function did not set caps. Setting"); gst_buffer_set_caps (*buf, caps); } return ret; flushing: { /* pad was flushing */ GST_OBJECT_UNLOCK (pad); GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad was flushing"); return GST_FLOW_WRONG_STATE; } error: { GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "alloc function returned error (%d) %s", ret, gst_flow_get_name (ret)); return ret; } fallback: { /* fallback case, allocate a buffer of our own, add pad caps. */ GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fallback buffer alloc"); *buf = gst_buffer_new_and_alloc (size); GST_BUFFER_OFFSET (*buf) = offset; gst_buffer_set_caps (*buf, caps); return GST_FLOW_OK; } } static GstFlowReturn gst_pad_alloc_buffer_full (GstPad * pad, guint64 offset, gint size, GstCaps * caps, GstBuffer ** buf, gboolean setcaps) { GstPad *peer; GstFlowReturn ret; gboolean caps_changed; g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR); g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR); g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR); GST_OBJECT_LOCK (pad); while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) if ((ret = handle_pad_block (pad)) != GST_FLOW_OK) goto flushed; if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL)) goto no_peer; gst_object_ref (peer); GST_OBJECT_UNLOCK (pad); ret = gst_pad_buffer_alloc_unchecked (peer, offset, size, caps, buf); gst_object_unref (peer); if (G_UNLIKELY (ret != GST_FLOW_OK)) goto peer_error; /* FIXME, move capnego this into a base class? */ caps = GST_BUFFER_CAPS (*buf); /* Lock for checking caps, pretty pointless as the _pad_push() function might * change it concurrently, one of the problems with automatic caps setting in * pad_alloc_and_set_caps. Worst case, if does a check too much, but only when * there is heavy renegotiation going on in both directions. */ GST_OBJECT_LOCK (pad); caps_changed = caps && caps != GST_PAD_CAPS (pad); GST_OBJECT_UNLOCK (pad); /* we got a new datatype on the pad, see if it can handle it */ if (G_UNLIKELY (caps_changed)) { GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps); if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, setcaps))) goto not_negotiated; } return ret; flushed: { GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad block stopped by flush"); GST_OBJECT_UNLOCK (pad); return ret; } no_peer: { /* pad has no peer */ GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "called bufferallocfunc but had no peer"); GST_OBJECT_UNLOCK (pad); return GST_FLOW_NOT_LINKED; } peer_error: { GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "alloc function returned error %s", gst_flow_get_name (ret)); return ret; } not_negotiated: { gst_buffer_unref (*buf); *buf = NULL; GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "alloc function returned unacceptable buffer"); return GST_FLOW_NOT_NEGOTIATED; } } /** * gst_pad_alloc_buffer: * @pad: a source #GstPad * @offset: the offset of the new buffer in the stream * @size: the size of the new buffer * @caps: the caps of the new buffer * @buf: a newly allocated buffer * * Allocates a new, empty buffer optimized to push to pad @pad. This * function only works if @pad is a source pad and has a peer. * * A new, empty #GstBuffer will be put in the @buf argument. * You need to check the caps of the buffer after performing this * function and renegotiate to the format if needed. * * Returns: a result code indicating success of the operation. Any * result code other than #GST_FLOW_OK is an error and @buf should * not be used. * An error can occur if the pad is not connected or when the downstream * peer elements cannot provide an acceptable buffer. * * MT safe. */ GstFlowReturn gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps, GstBuffer ** buf) { return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, FALSE); } /** * gst_pad_alloc_buffer_and_set_caps: * @pad: a source #GstPad * @offset: the offset of the new buffer in the stream * @size: the size of the new buffer * @caps: the caps of the new buffer * @buf: a newly allocated buffer * * In addition to the function gst_pad_alloc_buffer(), this function * automatically calls gst_pad_set_caps() when the caps of the * newly allocated buffer are different from the @pad caps. * * Returns: a result code indicating success of the operation. Any * result code other than #GST_FLOW_OK is an error and @buf should * not be used. * An error can occur if the pad is not connected or when the downstream * peer elements cannot provide an acceptable buffer. * * MT safe. */ GstFlowReturn gst_pad_alloc_buffer_and_set_caps (GstPad * pad, guint64 offset, gint size, GstCaps * caps, GstBuffer ** buf) { return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, TRUE); } /** * gst_pad_get_internal_links_default: * @pad: the #GstPad to get the internal links of. * * Gets a list of pads to which the given pad is linked to * inside of the parent element. * This is the default handler, and thus returns a list of all of the * pads inside the parent element with opposite direction. * The caller must free this list after use. * * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent. * * Not MT safe. */ GList * gst_pad_get_internal_links_default (GstPad * pad) { GList *res = NULL; GstElement *parent; GList *parent_pads; GstPadDirection direction; g_return_val_if_fail (GST_IS_PAD (pad), NULL); direction = pad->direction; parent = GST_PAD_PARENT (pad); if (!parent) return NULL; parent_pads = parent->pads; while (parent_pads) { GstPad *parent_pad = GST_PAD_CAST (parent_pads->data); if (parent_pad->direction != direction) { res = g_list_prepend (res, parent_pad); } parent_pads = g_list_next (parent_pads); } return res; } /** * gst_pad_get_internal_links: * @pad: the #GstPad to get the internal links of. * * Gets a list of pads to which the given pad is linked to * inside of the parent element. * The caller must free this list after use. * * Returns: a newly allocated #GList of pads. * * Not MT safe. */ GList * gst_pad_get_internal_links (GstPad * pad) { GList *res = NULL; g_return_val_if_fail (GST_IS_PAD (pad), NULL); if (GST_PAD_INTLINKFUNC (pad)) res = GST_PAD_INTLINKFUNC (pad) (pad); return res; } static gboolean gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event) { GList *orig, *pads; gboolean result; GST_INFO_OBJECT (pad, "Sending event %p (%s) to all internally linked pads", event, GST_EVENT_TYPE_NAME (event)); result = (GST_PAD_DIRECTION (pad) == GST_PAD_SINK); orig = pads = gst_pad_get_internal_links (pad); while (pads) { GstPad *eventpad = GST_PAD_CAST (pads->data); pads = g_list_next (pads); if (GST_PAD_DIRECTION (eventpad) == GST_PAD_SRC) { /* for each pad we send to, we should ref the event; it's up * to downstream to unref again when handled. */ GST_LOG_OBJECT (pad, "Reffing and sending event %p (%s) to %s:%s", event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad)); gst_event_ref (event); gst_pad_push_event (eventpad, event); } else { /* we only send the event on one pad, multi-sinkpad elements * should implement a handler */ GST_LOG_OBJECT (pad, "sending event %p (%s) to one sink pad %s:%s", event, GST_EVENT_TYPE_NAME (event), GST_DEBUG_PAD_NAME (eventpad)); result = gst_pad_push_event (eventpad, event); goto done; } } /* we handled the incoming event so we unref once */ GST_LOG_OBJECT (pad, "handled event %p, unreffing", event); gst_event_unref (event); done: g_list_free (orig); return result; } /** * gst_pad_event_default: * @pad: a #GstPad to call the default event handler on. * @event: the #GstEvent to handle. * * Invokes the default event handler for the given pad. End-of-stream and * discontinuity events are handled specially, and then the event is sent to all * pads internally linked to @pad. Note that if there are many possible sink * pads that are internally linked to @pad, only one will be sent an event. * Multi-sinkpad elements should implement custom event handlers. * * Returns: TRUE if the event was sent succesfully. */ gboolean gst_pad_event_default (GstPad * pad, GstEvent * event) { g_return_val_if_fail (GST_IS_PAD (pad), FALSE); g_return_val_if_fail (event != NULL, FALSE); switch (GST_EVENT_TYPE (event)) { case GST_EVENT_EOS: { GST_DEBUG_OBJECT (pad, "pausing task because of eos"); gst_pad_pause_task (pad); } default: break; } return gst_pad_event_default_dispatch (pad, event); } /** * gst_pad_dispatcher: * @pad: a #GstPad to dispatch. * @dispatch: the #GstDispatcherFunction to call. * @data: gpointer user data passed to the dispatcher function. * * Invokes the given dispatcher function on each respective peer of * all pads that are internally linked to the given pad. * The GstPadDispatcherFunction should return TRUE when no further pads * need to be processed. * * Returns: TRUE if one of the dispatcher functions returned TRUE. */ gboolean gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch, gpointer data) { gboolean res = FALSE; GList *int_pads, *orig; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); g_return_val_if_fail (dispatch != NULL, FALSE); orig = int_pads = gst_pad_get_internal_links (pad); while (int_pads) { GstPad *int_pad = GST_PAD_CAST (int_pads->data); GstPad *int_peer = GST_PAD_PEER (int_pad); if (int_peer) { res = dispatch (int_peer, data); if (res) break; } int_pads = g_list_next (int_pads); } g_list_free (orig); return res; } /** * gst_pad_query: * @pad: a #GstPad to invoke the default query on. * @query: the #GstQuery to perform. * * Dispatches a query to a pad. The query should have been allocated by the * caller via one of the type-specific allocation functions in gstquery.h. The * element is responsible for filling the query with an appropriate response, * which should then be parsed with a type-specific query parsing function. * * Again, the caller is responsible for both the allocation and deallocation of * the query structure. * * Returns: TRUE if the query could be performed. */ gboolean gst_pad_query (GstPad * pad, GstQuery * query) { GstPadQueryFunction func; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); g_return_val_if_fail (GST_IS_QUERY (query), FALSE); GST_DEBUG_OBJECT (pad, "sending query %p", query); if ((func = GST_PAD_QUERYFUNC (pad)) == NULL) goto no_func; return func (pad, query); no_func: { GST_DEBUG_OBJECT (pad, "had no query function"); return FALSE; } } /** * gst_pad_query_default: * @pad: a #GstPad to call the default query handler on. * @query: the #GstQuery to handle. * * Invokes the default query handler for the given pad. * The query is sent to all pads internally linked to @pad. Note that * if there are many possible sink pads that are internally linked to * @pad, only one will be sent the query. * Multi-sinkpad elements should implement custom query handlers. * * Returns: TRUE if the query was performed succesfully. */ gboolean gst_pad_query_default (GstPad * pad, GstQuery * query) { switch (GST_QUERY_TYPE (query)) { case GST_QUERY_POSITION: case GST_QUERY_SEEKING: case GST_QUERY_FORMATS: case GST_QUERY_LATENCY: case GST_QUERY_JITTER: case GST_QUERY_RATE: case GST_QUERY_CONVERT: default: return gst_pad_dispatcher (pad, (GstPadDispatcherFunction) gst_pad_query, query); } } #ifndef GST_DISABLE_LOADSAVE /* FIXME: why isn't this on a GstElement ? */ /** * gst_pad_load_and_link: * @self: an #xmlNodePtr to read the description from. * @parent: the #GstObject element that owns the pad. * * Reads the pad definition from the XML node and links the given pad * in the element to a pad of an element up in the hierarchy. */ void gst_pad_load_and_link (xmlNodePtr self, GstObject * parent) { xmlNodePtr field = self->xmlChildrenNode; GstPad *pad = NULL, *targetpad; gchar *peer = NULL; gchar **split; GstElement *target; GstObject *grandparent; gchar *name = NULL; while (field) { if (!strcmp ((char *) field->name, "name")) { name = (gchar *) xmlNodeGetContent (field); pad = gst_element_get_pad (GST_ELEMENT (parent), name); g_free (name); } else if (!strcmp ((char *) field->name, "peer")) { peer = (gchar *) xmlNodeGetContent (field); } field = field->next; } g_return_if_fail (pad != NULL); if (peer == NULL) return; split = g_strsplit (peer, ".", 2); if (split[0] == NULL || split[1] == NULL) { GST_CAT_DEBUG_OBJECT (GST_CAT_XML, pad, "Could not parse peer '%s', leaving unlinked", peer); g_free (peer); return; } g_free (peer); g_return_if_fail (split[0] != NULL); g_return_if_fail (split[1] != NULL); grandparent = gst_object_get_parent (parent); if (grandparent && GST_IS_BIN (grandparent)) { target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]); } else goto cleanup; if (target == NULL) goto cleanup; targetpad = gst_element_get_pad (target, split[1]); if (targetpad == NULL) goto cleanup; gst_pad_link (pad, targetpad); cleanup: g_strfreev (split); } /** * gst_pad_save_thyself: * @pad: a #GstPad to save. * @parent: the parent #xmlNodePtr to save the description in. * * Saves the pad into an xml representation. * * Returns: the #xmlNodePtr representation of the pad. */ static xmlNodePtr gst_pad_save_thyself (GstObject * object, xmlNodePtr parent) { GstPad *pad; GstPad *peer; g_return_val_if_fail (GST_IS_PAD (object), NULL); pad = GST_PAD (object); xmlNewChild (parent, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad)); if (GST_PAD_IS_SRC (pad)) { xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "source"); } else if (GST_PAD_IS_SINK (pad)) { xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "sink"); } else { xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "unknown"); } if (GST_PAD_PEER (pad) != NULL) { gchar *content; peer = GST_PAD_PEER (pad); /* first check to see if the peer's parent's parent is the same */ /* we just save it off */ content = g_strdup_printf ("%s.%s", GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer)); xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content); g_free (content); } else xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL); return parent; } #if 0 /** * gst_ghost_pad_save_thyself: * @pad: a ghost #GstPad to save. * @parent: the parent #xmlNodePtr to save the description in. * * Saves the ghost pad into an xml representation. * * Returns: the #xmlNodePtr representation of the pad. */ xmlNodePtr gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent) { xmlNodePtr self; g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL); self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL); xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad)); xmlNewChild (self, NULL, (xmlChar *) "parent", (xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad))); /* FIXME FIXME FIXME! */ return self; } #endif /* 0 */ #endif /* GST_DISABLE_LOADSAVE */ /* * should be called with pad OBJECT_LOCK and STREAM_LOCK held. * GST_PAD_IS_BLOCKED (pad) == TRUE when this function is * called. * * This function perform the pad blocking when an event, buffer push * or buffer_alloc is performed on a _SRC_ pad. It blocks the * streaming thread after informing the pad has been blocked. * * An application can with this method wait and block any streaming * thread and perform operations such as seeking or linking. * * Two methods are available for notifying the application of the * block: * - the callback method, which happens in the STREAMING thread with * the STREAM_LOCK held. With this method, the most usefull way of * dealing with the callback is to post a message to the main thread * where the pad block can then be handled outside of the streaming * thread. With the last method one can perform all operations such * as doing a state change, linking, unblocking, seeking etc on the * pad. * - the GCond signal method, which makes any thread unblock when * the pad block happens. * * During the actual blocking state, the GST_PAD_BLOCKING flag is set. * The GST_PAD_BLOCKING flag is unset when the pad was unblocked. * * MT safe. */ static GstFlowReturn handle_pad_block (GstPad * pad) { GstPadBlockCallback callback; gpointer user_data; GstFlowReturn ret = GST_FLOW_OK; GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "signal block taken"); /* flushing, don't bother trying to block and return WRONG_STATE * right away */ if (GST_PAD_IS_FLUSHING (pad)) goto flushingnonref; /* we grab an extra ref for the callbacks, this is probably not * needed (callback code does not have a ref and cannot unref). I * think this was done to make it possible to unref the element in * the callback, which is in the end totally impossible as it * requires grabbing the STREAM_LOCK and OBJECT_LOCK which are * all taken when calling this function. */ gst_object_ref (pad); /* we either have a callback installed to notify the block or * some other thread is doing a GCond wait. */ callback = pad->block_callback; if (callback) { /* there is a callback installed, call it. We release the * lock so that the callback can do something usefull with the * pad */ user_data = pad->block_data; GST_OBJECT_UNLOCK (pad); callback (pad, TRUE, user_data); GST_OBJECT_LOCK (pad); /* we released the lock, recheck flushing */ if (GST_PAD_IS_FLUSHING (pad)) goto flushing; } else { /* no callback, signal the thread that is doing a GCond wait * if any. */ GST_PAD_BLOCK_BROADCAST (pad); } /* OBJECT_LOCK could have been released when we did the callback, which * then could have made the pad unblock so we need to check the blocking * condition again. */ while (GST_PAD_IS_BLOCKED (pad)) { /* now we block the streaming thread. It can be unlocked when we * deactivate the pad (which will also set the FLUSHING flag) or * when the pad is unblocked. A flushing event will also unblock * the pad after setting the FLUSHING flag. */ GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "Waiting to be unblocked or set flushing"); GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKING); GST_PAD_BLOCK_WAIT (pad); GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKING); /* see if we got unblocked by a flush or not */ if (GST_PAD_IS_FLUSHING (pad)) goto flushing; } GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked"); /* when we get here, the pad is unblocked again and we perform * the needed unblock code. */ callback = pad->block_callback; if (callback) { /* we need to call the callback */ user_data = pad->block_data; GST_OBJECT_UNLOCK (pad); callback (pad, FALSE, user_data); GST_OBJECT_LOCK (pad); } else { /* we need to signal the thread waiting on the GCond */ GST_PAD_BLOCK_BROADCAST (pad); } gst_object_unref (pad); return ret; flushingnonref: { GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad was flushing"); return GST_FLOW_WRONG_STATE; } flushing: { GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad became flushing"); gst_object_unref (pad); return GST_FLOW_WRONG_STATE; } } /********************************************************************** * Data passing functions */ static gboolean gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj) { GValue ret = { 0 }; GValue args[2] = { {0}, {0} }; gboolean res; GQuark detail; /* init */ g_value_init (&ret, G_TYPE_BOOLEAN); g_value_set_boolean (&ret, TRUE); g_value_init (&args[0], GST_TYPE_PAD); g_value_set_object (&args[0], pad); g_value_init (&args[1], GST_TYPE_MINI_OBJECT); // G_TYPE_POINTER); gst_value_set_mini_object (&args[1], obj); if (GST_IS_EVENT (obj)) detail = event_quark; else detail = buffer_quark; /* actually emit */ g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret); res = g_value_get_boolean (&ret); /* clean up */ g_value_unset (&ret); g_value_unset (&args[0]); g_value_unset (&args[1]); return res; } /* this is the chain function that does not perform the additional argument * checking for that little extra speed. */ static inline GstFlowReturn gst_pad_chain_unchecked (GstPad * pad, GstBuffer * buffer) { GstCaps *caps; gboolean caps_changed; GstPadChainFunction chainfunc; GstFlowReturn ret; gboolean emit_signal; GST_PAD_STREAM_LOCK (pad); GST_OBJECT_LOCK (pad); if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad))) goto flushing; caps = GST_BUFFER_CAPS (buffer); caps_changed = caps && caps != GST_PAD_CAPS (pad); emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0; GST_OBJECT_UNLOCK (pad); /* see if the signal should be emited, we emit before caps nego as * we might drop the buffer and do capsnego for nothing. */ if (G_UNLIKELY (emit_signal)) { if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer))) goto dropping; } /* we got a new datatype on the pad, see if it can handle it */ if (G_UNLIKELY (caps_changed)) { GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps); if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps))) goto not_negotiated; } /* NOTE: we read the chainfunc unlocked. * we cannot hold the lock for the pad so we might send * the data to the wrong function. This is not really a * problem since functions are assigned at creation time * and don't change that often... */ if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL)) goto no_function; GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "calling chainfunction &%s", GST_DEBUG_FUNCPTR_NAME (chainfunc)); ret = chainfunc (pad, buffer); GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "called chainfunction &%s, returned %s", GST_DEBUG_FUNCPTR_NAME (chainfunc), gst_flow_get_name (ret)); GST_PAD_STREAM_UNLOCK (pad); return ret; /* ERRORS */ flushing: { gst_buffer_unref (buffer); GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pushing, but pad was flushing"); GST_OBJECT_UNLOCK (pad); GST_PAD_STREAM_UNLOCK (pad); return GST_FLOW_WRONG_STATE; } dropping: { gst_buffer_unref (buffer); GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return"); GST_PAD_STREAM_UNLOCK (pad); return GST_FLOW_OK; } not_negotiated: { gst_buffer_unref (buffer); GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pushing buffer but pad did not accept"); GST_PAD_STREAM_UNLOCK (pad); return GST_FLOW_NOT_NEGOTIATED; } no_function: { gst_buffer_unref (buffer); GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pushing, but not chainhandler"); GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL), ("push on pad %s:%s but it has no chainfunction", GST_DEBUG_PAD_NAME (pad))); GST_PAD_STREAM_UNLOCK (pad); return GST_FLOW_NOT_SUPPORTED; } } /** * gst_pad_chain: * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not. * @buffer: the #GstBuffer to send, return GST_FLOW_ERROR if not. * * Chain a buffer to @pad. * * The function returns #GST_FLOW_WRONG_STATE if the pad was flushing. * * If the caps on @buffer are different from the current caps on @pad, this * function will call any setcaps function (see gst_pad_set_setcaps_function()) * installed on @pad. If the new caps are not acceptable for @pad, this function * returns #GST_FLOW_NOT_NEGOTIATED. * * The function proceeds calling the chain function installed on @pad (see * gst_pad_set_chain_function()) and the return value of that function is * returned to the caller. #GST_FLOW_NOT_SUPPORTED is returned if @pad has no * chain function. * * In all cases, success or failure, the caller loses its reference to @buffer * after calling this function. * * Returns: a #GstFlowReturn from the pad. * * MT safe. */ GstFlowReturn gst_pad_chain (GstPad * pad, GstBuffer * buffer) { g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR); g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK, GST_FLOW_ERROR); g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR); return gst_pad_chain_unchecked (pad, buffer); } /** * gst_pad_push: * @pad: a source #GstPad, returns #GST_FLOW_ERROR if not. * @buffer: the #GstBuffer to push returns GST_FLOW_ERROR if not. * * Pushes a buffer to the peer of @pad. * * This function will call an installed pad block before triggering any * installed pad probes. * * If the caps on @buffer are different from the currently configured caps on * @pad, this function will call any installed setcaps function on @pad (see * gst_pad_set_setcaps_function()). In case of failure to renegotiate the new * format, this function returns #GST_FLOW_NOT_NEGOTIATED. * * The function proceeds calling gst_pad_chain() on the peer pad and returns the * value from that function. If @pad has no peer, #GST_FLOW_NOT_LINKED will be * returned. * * In all cases, success or failure, the caller loses its reference to @buffer * after calling this function. * * Returns: a #GstFlowReturn from the peer pad. * * MT safe. */ GstFlowReturn gst_pad_push (GstPad * pad, GstBuffer * buffer) { GstPad *peer; GstFlowReturn ret; GstCaps *caps; gboolean caps_changed; g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR); g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR); g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR); GST_OBJECT_LOCK (pad); /* FIXME: this check can go away; pad_set_blocked could be implemented with * probes completely or probes with an extended pad block. */ while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) if ((ret = handle_pad_block (pad)) != GST_FLOW_OK) goto flushed; /* we emit signals on the pad arg, the peer will have a chance to * emit in the _chain() function */ if (G_UNLIKELY (GST_PAD_DO_BUFFER_SIGNALS (pad) > 0)) { /* unlock before emitting */ GST_OBJECT_UNLOCK (pad); /* if the signal handler returned FALSE, it means we should just drop the * buffer */ if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (buffer))) goto dropped; GST_OBJECT_LOCK (pad); } if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL)) goto not_linked; /* take ref to peer pad before releasing the lock */ gst_object_ref (peer); /* Before pushing the buffer to the peer pad, ensure that caps * are set on this pad */ caps = GST_BUFFER_CAPS (buffer); caps_changed = caps && caps != GST_PAD_CAPS (pad); GST_OBJECT_UNLOCK (pad); /* we got a new datatype from the pad, it had better handle it */ if (G_UNLIKELY (caps_changed)) { GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps); if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE))) goto not_negotiated; } ret = gst_pad_chain_unchecked (peer, buffer); gst_object_unref (peer); return ret; /* ERROR recovery here */ flushed: { gst_buffer_unref (buffer); GST_DEBUG_OBJECT (pad, "pad block stopped by flush"); GST_OBJECT_UNLOCK (pad); return ret; } dropped: { gst_buffer_unref (buffer); GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return"); return GST_FLOW_OK; } not_linked: { gst_buffer_unref (buffer); GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pushing, but it was not linked"); GST_OBJECT_UNLOCK (pad); return GST_FLOW_NOT_LINKED; } not_negotiated: { gst_buffer_unref (buffer); gst_object_unref (peer); GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad, "element pushed buffer then refused to accept the caps"); return GST_FLOW_NOT_NEGOTIATED; } } /** * gst_pad_check_pull_range: * @pad: a sink #GstPad. * * Checks if a gst_pad_pull_range() can be performed on the peer * source pad. This function is used by plugins that want to check * if they can use random access on the peer source pad. * * The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction * if it needs to perform some logic to determine if pull_range is * possible. * * Returns: a gboolean with the result. * * MT safe. */ gboolean gst_pad_check_pull_range (GstPad * pad) { GstPad *peer; gboolean ret; GstPadCheckGetRangeFunction checkgetrangefunc; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); GST_OBJECT_LOCK (pad); if (GST_PAD_DIRECTION (pad) != GST_PAD_SINK) goto wrong_direction; if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL)) goto not_connected; gst_object_ref (peer); GST_OBJECT_UNLOCK (pad); /* see note in above function */ if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) { /* FIXME, kindoff ghetto */ ret = GST_PAD_GETRANGEFUNC (peer) != NULL; } else { GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "calling checkgetrangefunc %s of peer pad %s:%s", GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer)); ret = checkgetrangefunc (peer); } gst_object_unref (peer); return ret; /* ERROR recovery here */ wrong_direction: { GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "checking pull range, but pad must be a sinkpad"); GST_OBJECT_UNLOCK (pad); return FALSE; } not_connected: { GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "checking pull range, but it was not linked"); GST_OBJECT_UNLOCK (pad); return FALSE; } } /** * gst_pad_get_range: * @pad: a src #GstPad, returns #GST_FLOW_ERROR if not. * @offset: The start offset of the buffer * @size: The length of the buffer * @buffer: a pointer to hold the #GstBuffer, returns #GST_FLOW_ERROR if %NULL. * * When @pad is flushing this function returns #GST_FLOW_WRONG_STATE * immediatly. * * Calls the getrange function of @pad, see #GstPadGetRangeFunction for a * description of a getrange function. If @pad has no getrange function * installed (see gst_pad_set_getrange_function()) this function returns * #GST_FLOW_NOT_SUPPORTED. * * @buffer's caps must either be unset or the same as what is already configured * on @pad. Renegotiation within a running pull-mode pipeline is not supported. * * Returns: a #GstFlowReturn from the pad. * * MT safe. */ GstFlowReturn gst_pad_get_range (GstPad * pad, guint64 offset, guint size, GstBuffer ** buffer) { GstFlowReturn ret; GstPadGetRangeFunction getrangefunc; gboolean emit_signal; g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR); g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SRC, GST_FLOW_ERROR); g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR); GST_PAD_STREAM_LOCK (pad); GST_OBJECT_LOCK (pad); if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad))) goto flushing; emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0; GST_OBJECT_UNLOCK (pad); if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL)) goto no_function; GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "calling getrangefunc %s, offset %" G_GUINT64_FORMAT ", size %u", GST_DEBUG_FUNCPTR_NAME (getrangefunc), offset, size); ret = getrangefunc (pad, offset, size, buffer); /* can only fire the signal if we have a valid buffer */ if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) { if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer))) goto dropping; } GST_PAD_STREAM_UNLOCK (pad); if (G_LIKELY (ret == GST_FLOW_OK)) { GstCaps *caps; gboolean caps_changed; GST_OBJECT_LOCK (pad); /* Before pushing the buffer to the peer pad, ensure that caps * are set on this pad */ caps = GST_BUFFER_CAPS (*buffer); caps_changed = caps && caps != GST_PAD_CAPS (pad); GST_OBJECT_UNLOCK (pad); /* we got a new datatype from the pad not supported in a running pull-mode * pipeline */ if (G_UNLIKELY (caps_changed)) goto not_negotiated; } return ret; /* ERRORS */ flushing: { GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pulling range, but pad was flushing"); GST_OBJECT_UNLOCK (pad); GST_PAD_STREAM_UNLOCK (pad); return GST_FLOW_WRONG_STATE; } no_function: { GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL), ("pullrange on pad %s:%s but it has no getrangefunction", GST_DEBUG_PAD_NAME (pad))); GST_PAD_STREAM_UNLOCK (pad); return GST_FLOW_NOT_SUPPORTED; } dropping: { GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "Dropping data after FALSE probe return"); GST_PAD_STREAM_UNLOCK (pad); gst_buffer_unref (*buffer); *buffer = NULL; return GST_FLOW_UNEXPECTED; } not_negotiated: { gst_buffer_unref (*buffer); *buffer = NULL; GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad, "getrange returned buffer of different caps"); return GST_FLOW_NOT_NEGOTIATED; } } /** * gst_pad_pull_range: * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not. * @offset: The start offset of the buffer * @size: The length of the buffer * @buffer: a pointer to hold the #GstBuffer, returns GST_FLOW_ERROR if %NULL. * * Pulls a buffer from the peer pad. * * This function will first trigger the pad block signal if it was * installed. * * When @pad is not linked #GST_FLOW_NOT_LINKED is returned else this * function returns the result of gst_pad_get_range() on the peer pad. * See gst_pad_get_range() for a list of return values and for the * semantics of the arguments of this function. * * @buffer's caps must either be unset or the same as what is already configured * on @pad. Renegotiation within a running pull-mode pipeline is not supported. * * Returns: a #GstFlowReturn from the peer pad. * When this function returns #GST_FLOW_OK, @buffer will contain a valid * #GstBuffer that should be freed with gst_buffer_unref() after usage. * @buffer may not be used or freed when any other return value than * #GST_FLOW_OK is returned. * * MT safe. */ GstFlowReturn gst_pad_pull_range (GstPad * pad, guint64 offset, guint size, GstBuffer ** buffer) { GstPad *peer; GstFlowReturn ret; gboolean emit_signal; g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR); g_return_val_if_fail (GST_PAD_DIRECTION (pad) == GST_PAD_SINK, GST_FLOW_ERROR); g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR); GST_OBJECT_LOCK (pad); while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) handle_pad_block (pad); if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL)) goto not_connected; /* signal emision for the pad, peer has chance to emit when * we call _get_range() */ emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0; gst_object_ref (peer); GST_OBJECT_UNLOCK (pad); ret = gst_pad_get_range (peer, offset, size, buffer); gst_object_unref (peer); /* can only fire the signal if we have a valid buffer */ if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) { if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer))) goto dropping; } if (G_LIKELY (ret == GST_FLOW_OK)) { GstCaps *caps; gboolean caps_changed; GST_OBJECT_LOCK (pad); /* Before pushing the buffer to the peer pad, ensure that caps * are set on this pad */ caps = GST_BUFFER_CAPS (*buffer); caps_changed = caps && caps != GST_PAD_CAPS (pad); GST_OBJECT_UNLOCK (pad); /* we got a new datatype on the pad, see if it can handle it */ if (G_UNLIKELY (caps_changed)) goto not_negotiated; } return ret; /* ERROR recovery here */ not_connected: { GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pulling range, but it was not linked"); GST_OBJECT_UNLOCK (pad); return GST_FLOW_NOT_LINKED; } dropping: { GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "Dropping data after FALSE probe return"); gst_buffer_unref (*buffer); *buffer = NULL; return GST_FLOW_UNEXPECTED; } not_negotiated: { gst_buffer_unref (*buffer); *buffer = NULL; GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad, "pullrange returned buffer of different caps"); return GST_FLOW_NOT_NEGOTIATED; } } /** * gst_pad_push_event: * @pad: a #GstPad to push the event to. * @event: the #GstEvent to send to the pad. * * Sends the event to the peer of the given pad. This function is * mainly used by elements to send events to their peer * elements. * * This function takes owership of the provided event so you should * gst_event_ref() it if you want to reuse the event after this call. * * Returns: TRUE if the event was handled. * * MT safe. */ gboolean gst_pad_push_event (GstPad * pad, GstEvent * event) { GstPad *peerpad; gboolean result; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); g_return_val_if_fail (event != NULL, FALSE); g_return_val_if_fail (GST_IS_EVENT (event), FALSE); GST_LOG_OBJECT (pad, "event: %s", GST_EVENT_TYPE_NAME (event)); GST_OBJECT_LOCK (pad); /* Two checks to be made: * . (un)set the FLUSHING flag for flushing events, * . handle pad blocking */ switch (GST_EVENT_TYPE (event)) { case GST_EVENT_FLUSH_START: GST_PAD_SET_FLUSHING (pad); if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) { /* flush start will have set the FLUSHING flag and will then * unlock all threads doing a GCond wait on the blocking pad. This * will typically unblock the STREAMING thread blocked on a pad. */ GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-start, " "doing block signal."); GST_PAD_BLOCK_BROADCAST (pad); goto flushed; } break; case GST_EVENT_FLUSH_STOP: GST_PAD_UNSET_FLUSHING (pad); /* if we are blocked, flush away the FLUSH_STOP event */ if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) { GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-stop"); goto flushed; } break; default: while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) { /* block the event as long as the pad is blocked */ if (handle_pad_block (pad) != GST_FLOW_OK) goto flushed; } break; } if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) { GST_OBJECT_UNLOCK (pad); if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event))) goto dropping; GST_OBJECT_LOCK (pad); } peerpad = GST_PAD_PEER (pad); if (peerpad == NULL) goto not_linked; GST_LOG_OBJECT (pad, "sending event %s to peerpad %" GST_PTR_FORMAT, GST_EVENT_TYPE_NAME (event), peerpad); gst_object_ref (peerpad); GST_OBJECT_UNLOCK (pad); result = gst_pad_send_event (peerpad, event); /* Note: we gave away ownership of the event at this point */ GST_LOG_OBJECT (pad, "sent event to peerpad %" GST_PTR_FORMAT, peerpad); gst_object_unref (peerpad); return result; /* ERROR handling */ dropping: { GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return"); gst_event_unref (event); return FALSE; } not_linked: { GST_DEBUG_OBJECT (pad, "Dropping event because pad is not linked"); gst_event_unref (event); GST_OBJECT_UNLOCK (pad); return FALSE; } flushed: { GST_DEBUG_OBJECT (pad, "Not forwarding event since we're flushing and blocking"); gst_event_unref (event); GST_OBJECT_UNLOCK (pad); return TRUE; } } /** * gst_pad_send_event: * @pad: a #GstPad to send the event to. * @event: the #GstEvent to send to the pad. * * Sends the event to the pad. This function can be used * by applications to send events in the pipeline. * * If @pad is a source pad, @event should be an upstream event. If @pad is a * sink pad, @event should be a downstream event. For example, you would not * send a #GST_EVENT_EOS on a src pad; EOS events only propagate downstream. * Furthermore, some downstream events have to be serialized with data flow, * like EOS, while some can travel out-of-band, like #GST_EVENT_FLUSH_START. If * the event needs to be serialized with data flow, this function will take the * pad's stream lock while calling its event function. * * To find out whether an event type is upstream, downstream, or downstream and * serialized, see #GstEventTypeFlags, gst_event_type_get_flags(), * #GST_EVENT_IS_UPSTREAM, #GST_EVENT_IS_DOWNSTREAM, and * #GST_EVENT_IS_SERIALIZED. Note that in practice that an application or plugin * doesn't need to bother itself with this information; the core handles all * necessary locks and checks. * * This function takes owership of the provided event so you should * gst_event_ref() it if you want to reuse the event after this call. * * Returns: TRUE if the event was handled. */ gboolean gst_pad_send_event (GstPad * pad, GstEvent * event) { gboolean result = FALSE; GstPadEventFunction eventfunc; gboolean serialized, need_unlock = FALSE; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); g_return_val_if_fail (event != NULL, FALSE); GST_OBJECT_LOCK (pad); if (GST_PAD_IS_SINK (pad)) { if (G_UNLIKELY (!GST_EVENT_IS_DOWNSTREAM (event))) goto wrong_direction; serialized = GST_EVENT_IS_SERIALIZED (event); } else if (GST_PAD_IS_SRC (pad)) { if (G_UNLIKELY (!GST_EVENT_IS_UPSTREAM (event))) goto wrong_direction; /* events on srcpad never are serialized */ serialized = FALSE; } else goto unknown_direction; if (G_UNLIKELY (GST_EVENT_SRC (event) == NULL)) { GST_LOG_OBJECT (pad, "event had no source, setting pad as event source"); GST_EVENT_SRC (event) = gst_object_ref (pad); } /* pad signals */ if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) { GST_OBJECT_UNLOCK (pad); if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT_CAST (event))) goto dropping; GST_OBJECT_LOCK (pad); } switch (GST_EVENT_TYPE (event)) { case GST_EVENT_FLUSH_START: GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "have event type %d (FLUSH_START)", GST_EVENT_TYPE (event)); /* can't even accept a flush begin event when flushing */ if (GST_PAD_IS_FLUSHING (pad)) goto flushing; GST_PAD_SET_FLUSHING (pad); GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "set flush flag"); break; case GST_EVENT_FLUSH_STOP: GST_PAD_UNSET_FLUSHING (pad); GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "cleared flush flag"); GST_OBJECT_UNLOCK (pad); /* grab stream lock */ GST_PAD_STREAM_LOCK (pad); need_unlock = TRUE; GST_OBJECT_LOCK (pad); break; default: GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "have event type %s", GST_EVENT_TYPE_NAME (event)); /* make this a little faster, no point in grabbing the lock * if the pad is allready flushing. */ if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad))) goto flushing; if (serialized) { /* lock order: STREAM_LOCK, LOCK, recheck flushing. */ GST_OBJECT_UNLOCK (pad); GST_PAD_STREAM_LOCK (pad); need_unlock = TRUE; GST_OBJECT_LOCK (pad); if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad))) goto flushing; } break; } if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL)) goto no_function; GST_OBJECT_UNLOCK (pad); result = eventfunc (pad, event); if (need_unlock) GST_PAD_STREAM_UNLOCK (pad); return result; /* ERROR handling */ wrong_direction: { g_warning ("pad %s:%s sending %s event in wrong direction", GST_DEBUG_PAD_NAME (pad), GST_EVENT_TYPE_NAME (event)); GST_OBJECT_UNLOCK (pad); gst_event_unref (event); return FALSE; } unknown_direction: { g_warning ("pad %s:%s has invalid direction", GST_DEBUG_PAD_NAME (pad)); GST_OBJECT_UNLOCK (pad); gst_event_unref (event); return FALSE; } no_function: { g_warning ("pad %s:%s has no event handler, file a bug.", GST_DEBUG_PAD_NAME (pad)); GST_OBJECT_UNLOCK (pad); gst_event_unref (event); return FALSE; } flushing: { GST_OBJECT_UNLOCK (pad); if (need_unlock) GST_PAD_STREAM_UNLOCK (pad); GST_CAT_INFO_OBJECT (GST_CAT_EVENT, pad, "Received event on flushing pad. Discarding"); gst_event_unref (event); return FALSE; } dropping: { GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return"); gst_event_unref (event); return FALSE; } } /** * gst_pad_set_element_private: * @pad: the #GstPad to set the private data of. * @priv: The private data to attach to the pad. * * Set the given private data gpointer on the pad. * This function can only be used by the element that owns the pad. * No locking is performed in this function. */ void gst_pad_set_element_private (GstPad * pad, gpointer priv) { pad->element_private = priv; } /** * gst_pad_get_element_private: * @pad: the #GstPad to get the private data of. * * Gets the private data of a pad. * No locking is performed in this function. * * Returns: a #gpointer to the private data. */ gpointer gst_pad_get_element_private (GstPad * pad) { return pad->element_private; } /** * gst_pad_start_task: * @pad: the #GstPad to start the task of * @func: the task function to call * @data: data passed to the task function * * Starts a task that repeadedly calls @func with @data. This function * is nostly used in the pad activation function to start the * dataflow. This function will automatically acquire the #GST_PAD_STREAM_LOCK * of the pad before calling @func. * * Returns: a %TRUE if the task could be started. */ gboolean gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data) { GstTask *task; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); g_return_val_if_fail (func != NULL, FALSE); GST_DEBUG_OBJECT (pad, "start task"); GST_OBJECT_LOCK (pad); task = GST_PAD_TASK (pad); if (task == NULL) { task = gst_task_create (func, data); gst_task_set_lock (task, GST_PAD_GET_STREAM_LOCK (pad)); GST_PAD_TASK (pad) = task; GST_DEBUG_OBJECT (pad, "created task"); } gst_task_start (task); GST_OBJECT_UNLOCK (pad); return TRUE; } /** * gst_pad_pause_task: * @pad: the #GstPad to pause the task of * * Pause the task of @pad. This function will also make sure that the * function executed by the task will effectively stop. * * Returns: a TRUE if the task could be paused or FALSE when the pad * has no task. */ gboolean gst_pad_pause_task (GstPad * pad) { GstTask *task; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); GST_DEBUG_OBJECT (pad, "pause task"); GST_OBJECT_LOCK (pad); task = GST_PAD_TASK (pad); if (task == NULL) goto no_task; gst_task_pause (task); GST_OBJECT_UNLOCK (pad); GST_PAD_STREAM_LOCK (pad); GST_PAD_STREAM_UNLOCK (pad); return TRUE; no_task: { GST_DEBUG_OBJECT (pad, "pad has no task"); GST_OBJECT_UNLOCK (pad); return FALSE; } } /** * gst_pad_stop_task: * @pad: the #GstPad to stop the task of * * Stop the task of @pad. This function will also make sure that the * function executed by the task will effectively stop if not called * from the GstTaskFunction. * * This function will deadlock if called from the GstTaskFunction of * the task. Use gst_task_pause() instead. * * Regardless of whether the pad has a task, the stream lock is acquired and * released so as to ensure that streaming through this pad has finished. * * Returns: a TRUE if the task could be stopped or FALSE on error. */ gboolean gst_pad_stop_task (GstPad * pad) { GstTask *task; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); GST_DEBUG_OBJECT (pad, "stop task"); GST_OBJECT_LOCK (pad); task = GST_PAD_TASK (pad); if (task == NULL) goto no_task; GST_PAD_TASK (pad) = NULL; gst_task_stop (task); GST_OBJECT_UNLOCK (pad); GST_PAD_STREAM_LOCK (pad); GST_PAD_STREAM_UNLOCK (pad); if (!gst_task_join (task)) goto join_failed; gst_object_unref (task); return TRUE; no_task: { GST_DEBUG_OBJECT (pad, "no task"); GST_OBJECT_UNLOCK (pad); GST_PAD_STREAM_LOCK (pad); GST_PAD_STREAM_UNLOCK (pad); /* this is not an error */ return TRUE; } join_failed: { /* this is bad, possibly the application tried to join the task from * the task's thread. We install the task again so that it will be stopped * again from the right thread next time hopefully. */ GST_OBJECT_LOCK (pad); GST_DEBUG_OBJECT (pad, "join failed"); /* we can only install this task if there was no other task */ if (GST_PAD_TASK (pad) == NULL) GST_PAD_TASK (pad) = task; GST_OBJECT_UNLOCK (pad); return FALSE; } }