/* 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 */ }; #define GST_PAD_GET_PRIVATE(obj) \ (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_PAD, GstPadPrivate)) #define GST_PAD_CHAINLISTFUNC(pad) ((pad)->abidata.ABI.priv->chainlistfunc) struct _GstPadPrivate { GstPadChainListFunction chainlistfunc; }; 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); #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED) #ifdef GST_DISABLE_DEPRECATED #include #endif static xmlNodePtr gst_pad_save_thyself (GstObject * object, xmlNodePtr parent); void gst_pad_load_and_link (xmlNodePtr self, GstObject * parent); #endif /* Some deprecated stuff that we need inside here for * backwards compatibility */ #ifdef GST_DISABLE_DEPRECATED #ifndef GST_REMOVE_DEPRECATED #define GST_PAD_INTLINKFUNC(pad) (GST_PAD_CAST(pad)->intlinkfunc) GList *gst_pad_get_internal_links_default (GstPad * pad); #endif #endif static GstObjectClass *parent_class = NULL; static guint gst_pad_signals[LAST_SIGNAL] = { 0 }; static GParamSpec *pspec_caps = NULL; /* 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} }; /** * 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; i < G_N_ELEMENTS (flow_quarks); 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; i < G_N_ELEMENTS (flow_quarks); i++) { if (ret == flow_quarks[i].ret) return flow_quarks[i].quark; } return 0; } #define _do_init \ { \ gint i; \ \ buffer_quark = g_quark_from_static_string ("buffer"); \ event_quark = g_quark_from_static_string ("event"); \ \ for (i = 0; i < G_N_ELEMENTS (flow_quarks); 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"); \ } G_DEFINE_TYPE_WITH_CODE (GstPad, gst_pad, GST_TYPE_OBJECT, _do_init); 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); g_type_class_add_private (klass, sizeof (GstPadPrivate)); parent_class = g_type_class_peek_parent (klass); gobject_class->dispose = gst_pad_dispose; gobject_class->finalize = gst_pad_finalize; gobject_class->set_property = gst_pad_set_property; gobject_class->get_property = 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); pspec_caps = g_param_spec_boxed ("caps", "Caps", "The capabilities of the pad", GST_TYPE_CAPS, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS); g_object_class_install_property (gobject_class, PAD_PROP_CAPS, pspec_caps); 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 | G_PARAM_STATIC_STRINGS)); /* 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 | G_PARAM_STATIC_STRINGS)); #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED) gstobject_class->save_thyself = ((gpointer (*)(GstObject * object, gpointer self)) * GST_DEBUG_FUNCPTR (gst_pad_save_thyself)); #endif gstobject_class->path_string_separator = "."; /* Register common function pointer descriptions */ GST_DEBUG_REGISTER_FUNCPTR (gst_pad_activate_default); GST_DEBUG_REGISTER_FUNCPTR (gst_pad_event_default); GST_DEBUG_REGISTER_FUNCPTR (gst_pad_get_query_types_default); GST_DEBUG_REGISTER_FUNCPTR (gst_pad_query_default); #ifndef GST_REMOVE_DEPRECATED GST_DEBUG_REGISTER_FUNCPTR (gst_pad_get_internal_links_default); #endif GST_DEBUG_REGISTER_FUNCPTR (gst_pad_iterate_internal_links_default); GST_DEBUG_REGISTER_FUNCPTR (gst_pad_acceptcaps_default); klass->have_data = default_have_data; } static void gst_pad_init (GstPad * pad) { pad->abidata.ABI.priv = GST_PAD_GET_PRIVATE (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_pad_activate_default; GST_PAD_EVENTFUNC (pad) = gst_pad_event_default; GST_PAD_QUERYTYPEFUNC (pad) = gst_pad_get_query_types_default; GST_PAD_QUERYFUNC (pad) = gst_pad_query_default; #ifndef GST_REMOVE_DEPRECATED GST_PAD_INTLINKFUNC (pad) = gst_pad_get_internal_links_default; #endif GST_PAD_ITERINTLINKFUNC (pad) = gst_pad_iterate_internal_links_default; GST_PAD_ACCEPTCAPSFUNC (pad) = 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 (); /* FIXME 0.11: Store this directly in the instance struct */ pad->stream_rec_lock = g_slice_new (GStaticRecMutex); 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_CAST (object); GstPad *peer; GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, pad, "dispose"); /* unlink the peer pad */ if ((peer = gst_pad_get_peer (pad))) { /* window for MT unsafeness, someone else could unlink here * and then we call unlink with wrong pads. The unlink * function would catch this and safely return failed. */ if (GST_PAD_IS_SRC (pad)) gst_pad_unlink (pad, peer); else gst_pad_unlink (peer, pad); gst_object_unref (peer); } /* clear the caps */ gst_caps_replace (&GST_PAD_CAPS (pad), NULL); gst_pad_set_pad_template (pad, NULL); if (pad->block_destroy_data && pad->block_data) { pad->block_destroy_data (pad->block_data); pad->block_data = NULL; } G_OBJECT_CLASS (parent_class)->dispose (object); } static void gst_pad_finalize (GObject * object) { GstPad *pad = GST_PAD_CAST (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_slice_free (GStaticRecMutex, 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); result = GST_PAD_DIRECTION (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); GST_PAD_ACTIVATE_MODE (pad) = new_mode; /* 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); GST_DEBUG_OBJECT (pad, "stopped streaming"); 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: GST_DEBUG_OBJECT (pad, "activating pad from push"); ret = TRUE; break; case GST_ACTIVATE_PULL: GST_DEBUG_OBJECT (pad, "activating pad from pull"); ret = TRUE; break; case GST_ACTIVATE_NONE: GST_DEBUG_OBJECT (pad, "activating pad from none"); ret = (GST_PAD_ACTIVATEFUNC (pad)) (pad); break; } } else { switch (old) { case GST_ACTIVATE_PUSH: GST_DEBUG_OBJECT (pad, "deactivating pad from push"); ret = gst_pad_activate_push (pad, FALSE); break; case GST_ACTIVATE_PULL: GST_DEBUG_OBJECT (pad, "deactivating pad from pull"); ret = gst_pad_activate_pull (pad, FALSE); break; case GST_ACTIVATE_NONE: GST_DEBUG_OBJECT (pad, "deactivating pad from 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_OBJECT (pad, "Failed to activate 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: GST_DEBUG_OBJECT (pad, "activating pad from pull, was ok"); goto was_ok; case GST_ACTIVATE_PUSH: GST_DEBUG_OBJECT (pad, "activating pad from push, deactivate push first"); /* 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: GST_DEBUG_OBJECT (pad, "activating pad from none"); break; } } else { switch (old) { case GST_ACTIVATE_NONE: GST_DEBUG_OBJECT (pad, "deactivating pad from none, was ok"); goto was_ok; case GST_ACTIVATE_PUSH: GST_DEBUG_OBJECT (pad, "deactivating pad from push, weird"); /* 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: GST_DEBUG_OBJECT (pad, "deactivating pad from pull"); break; } } if (gst_pad_get_direction (pad) == GST_PAD_SINK) { if ((peer = gst_pad_get_peer (pad))) { GST_DEBUG_OBJECT (pad, "calling peer"); if (G_UNLIKELY (!gst_pad_activate_pull (peer, active))) goto peer_failed; gst_object_unref (peer); } else { /* there is no peer, this is only fatal when we activate. When we * deactivate, we must assume the application has unlinked the peer and * will deactivate it eventually. */ if (active) goto not_linked; else GST_DEBUG_OBJECT (pad, "deactivating unlinked pad"); } } 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: GST_DEBUG_OBJECT (pad, "activating pad from push, was ok"); goto was_ok; case GST_ACTIVATE_PULL: GST_DEBUG_OBJECT (pad, "activating pad from push, deactivating pull first"); /* 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: GST_DEBUG_OBJECT (pad, "activating pad from none"); break; } } else { switch (old) { case GST_ACTIVATE_NONE: GST_DEBUG_OBJECT (pad, "deactivating pad from none, was ok"); goto was_ok; case GST_ACTIVATE_PULL: GST_DEBUG_OBJECT (pad, "deactivating pad from pull, weird"); /* 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: GST_DEBUG_OBJECT (pad, "deactivating pad from 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_full: * @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 * @destroy_data: #GDestroyNotify for user_data * * 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 the * wrong parameters were passed or the pad was already in the requested state. * * MT safe. * * Since: 0.10.23 */ gboolean gst_pad_set_blocked_async_full (GstPad * pad, gboolean blocked, GstPadBlockCallback callback, gpointer user_data, GDestroyNotify destroy_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); if (pad->block_destroy_data && pad->block_data) pad->block_destroy_data (pad->block_data); pad->block_callback = callback; pad->block_data = user_data; pad->block_destroy_data = destroy_data; pad->abidata.ABI.block_callback_called = FALSE; 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); if (pad->block_destroy_data && pad->block_data) pad->block_destroy_data (pad->block_data); pad->block_callback = callback; pad->block_data = user_data; pad->block_destroy_data = destroy_data; pad->abidata.ABI.block_callback_called = FALSE; 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_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 the * 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) { return gst_pad_set_blocked_async_full (pad, blocked, callback, user_data, NULL); } /** * 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 if the * 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_IS_SINK (pad)); 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_chain_list_function: * @pad: a sink #GstPad. * @chainlist: the #GstPadChainListFunction to set. * * Sets the given chain list function for the pad. The chainlist function is * called to process a #GstBufferList input buffer list. See * #GstPadChainListFunction for more details. * * Since: 0.10.24 */ void gst_pad_set_chain_list_function (GstPad * pad, GstPadChainListFunction chainlist) { g_return_if_fail (GST_IS_PAD (pad)); g_return_if_fail (GST_PAD_IS_SINK (pad)); GST_PAD_CHAINLISTFUNC (pad) = chainlist; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "chainlistfunc set to %s", GST_DEBUG_FUNCPTR_NAME (chainlist)); } /** * 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_IS_SRC (pad)); 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_IS_SRC (pad)); 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 #GstPad of either direction. * @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_iterate_internal_links_function: * @pad: a #GstPad of either direction. * @iterintlink: the #GstPadIterIntLinkFunction to set. * * Sets the given internal link iterator function for the pad. * * Since: 0.10.21 */ void gst_pad_set_iterate_internal_links_function (GstPad * pad, GstPadIterIntLinkFunction iterintlink) { g_return_if_fail (GST_IS_PAD (pad)); GST_PAD_ITERINTLINKFUNC (pad) = iterintlink; GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "internal link iterator set to %s", GST_DEBUG_FUNCPTR_NAME (iterintlink)); } /** * 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. * * Deprecated: Use the thread-safe gst_pad_set_iterate_internal_links_function() */ #ifndef GST_REMOVE_DEPRECATED #ifdef GST_DISABLE_DEPRECATED void gst_pad_set_internal_link_function (GstPad * pad, GstPadIntLinkFunction intlink); #endif 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)); } #endif /* GST_REMOVE_DEPRECATED */ /** * 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 #GstPad::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) { gboolean result = FALSE; GstElement *parent = NULL; g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE); g_return_val_if_fail (GST_PAD_IS_SRC (srcpad), FALSE); g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE); g_return_val_if_fail (GST_PAD_IS_SINK (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); /* We need to notify the parent before taking any pad locks as the bin in * question might be waiting for a lock on the pad while holding its lock * that our message will try to take. */ if ((parent = GST_ELEMENT_CAST (gst_pad_get_parent (srcpad)))) { if (GST_IS_ELEMENT (parent)) { gst_element_post_message (parent, gst_message_new_structure_change (GST_OBJECT_CAST (sinkpad), GST_STRUCTURE_CHANGE_TYPE_PAD_UNLINK, parent, TRUE)); } else { gst_object_unref (parent); parent = NULL; } } GST_OBJECT_LOCK (srcpad); GST_OBJECT_LOCK (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 (srcpad, gst_pad_signals[PAD_UNLINKED], 0, sinkpad); g_signal_emit (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)); result = TRUE; done: if (parent != NULL) { gst_element_post_message (parent, gst_message_new_structure_change (GST_OBJECT_CAST (sinkpad), GST_STRUCTURE_CHANGE_TYPE_PAD_UNLINK, parent, FALSE)); gst_object_unref (parent); } return result; /* ERRORS */ 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); goto done; } } /** * 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, GstPadLinkCheck flags) { GstCaps *srccaps = NULL; GstCaps *sinkcaps = NULL; gboolean compatible = FALSE; if (!(flags & (GST_PAD_LINK_CHECK_CAPS | GST_PAD_LINK_CHECK_TEMPLATE_CAPS))) return TRUE; /* Doing the expensive caps checking takes priority over only checking the template caps */ if (flags & GST_PAD_LINK_CHECK_CAPS) { srccaps = gst_pad_get_caps_unlocked (src); sinkcaps = gst_pad_get_caps_unlocked (sink); } else { /* If one of the two pads doesn't have a template, consider the intersection * as valid.*/ if (G_UNLIKELY ((GST_PAD_PAD_TEMPLATE (src) == NULL) || (GST_PAD_PAD_TEMPLATE (sink) == NULL))) { compatible = TRUE; goto done; } srccaps = gst_caps_ref (GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (src))); sinkcaps = gst_caps_ref (GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (sink))); } GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, src, "src caps %" GST_PTR_FORMAT, srccaps); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, sink, "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 (G_UNLIKELY (srccaps == NULL || sinkcaps == NULL)) { if (srccaps) gst_caps_unref (srccaps); if (sinkcaps) gst_caps_unref (sinkcaps); goto done; } compatible = gst_caps_can_intersect (srccaps, sinkcaps); gst_caps_unref (srccaps); gst_caps_unref (sinkcaps); done: GST_CAT_DEBUG (GST_CAT_CAPS, "caps are %scompatible", (compatible ? "" : "not")); return compatible; } /* 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; /* only care about parents that are elements */ if (G_UNLIKELY (!GST_IS_ELEMENT (psrc) || !GST_IS_ELEMENT (psink))) goto no_element_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; } no_element_parent: { GST_CAT_DEBUG (GST_CAT_CAPS, "one of the pads has no element 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, GstPadLinkCheck flags) { 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_PEER (srcpad) != NULL)) goto src_was_linked; GST_OBJECT_LOCK (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 ((flags & GST_PAD_LINK_CHECK_HIERARCHY) && !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, flags)) goto no_format; /* FIXME check pad scheduling for non-empty intersection */ return GST_PAD_LINK_OK; 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; } 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_can_link: * @srcpad: the source #GstPad. * @sinkpad: the sink #GstPad. * * Checks if the source pad and the sink pad are compatible so they can be * linked. * * Returns: TRUE if the pads can be linked. */ gboolean gst_pad_can_link (GstPad * srcpad, GstPad * sinkpad) { GstPadLinkReturn result; /* generic checks */ 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_PADS, "check if %s:%s can link with %s:%s", GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad)); /* gst_pad_link_prepare does everything for us, we only release the locks * on the pads that it gets us. If this function returns !OK the locks are not * taken anymore. */ result = gst_pad_link_prepare (srcpad, sinkpad, GST_PAD_LINK_CHECK_DEFAULT); if (result != GST_PAD_LINK_OK) goto done; GST_OBJECT_UNLOCK (srcpad); GST_OBJECT_UNLOCK (sinkpad); done: return result == GST_PAD_LINK_OK; } /** * gst_pad_link_full: * @srcpad: the source #GstPad to link. * @sinkpad: the sink #GstPad to link. * @flags: the checks to validate when linking * * Links the source pad and the sink pad. * * This variant of #gst_pad_link provides a more granular control on the * checks being done when linking. While providing some considerable speedups * the caller of this method must be aware that wrong usage of those flags * can cause severe issues. Refer to the documentation of #GstPadLinkCheck * for more information. * * MT Safe. * * Returns: A result code indicating if the connection worked or * what went wrong. * * Since: 0.10.30 */ GstPadLinkReturn gst_pad_link_full (GstPad * srcpad, GstPad * sinkpad, GstPadLinkCheck flags) { GstPadLinkReturn result; GstElement *parent; g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED); g_return_val_if_fail (GST_PAD_IS_SRC (srcpad), GST_PAD_LINK_WRONG_DIRECTION); g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED); g_return_val_if_fail (GST_PAD_IS_SINK (sinkpad), GST_PAD_LINK_WRONG_DIRECTION); /* Notify the parent early. See gst_pad_unlink for details. */ if ((parent = GST_ELEMENT_CAST (gst_pad_get_parent (srcpad)))) { if (GST_IS_ELEMENT (parent)) { gst_element_post_message (parent, gst_message_new_structure_change (GST_OBJECT_CAST (sinkpad), GST_STRUCTURE_CHANGE_TYPE_PAD_LINK, parent, TRUE)); } else { gst_object_unref (parent); parent = NULL; } } /* prepare will also lock the two pads */ result = gst_pad_link_prepare (srcpad, sinkpad, flags); if (result != GST_PAD_LINK_OK) goto done; /* 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 (srcpad, gst_pad_signals[PAD_LINKED], 0, sinkpad); g_signal_emit (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); } done: if (parent) { gst_element_post_message (parent, gst_message_new_structure_change (GST_OBJECT_CAST (sinkpad), GST_STRUCTURE_CHANGE_TYPE_PAD_LINK, parent, FALSE)); gst_object_unref (parent); } return result; } /** * 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) { return gst_pad_link_full (srcpad, sinkpad, GST_PAD_LINK_CHECK_DEFAULT); } 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; GstPadTemplate *templ; 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 ((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 ((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; } /* this almost never happens */ GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad has no caps"); result = gst_caps_new_empty (); done: return result; } /* FIXME-0.11: what about making this the default and using * gst_caps_make_writable() explicitely where needed */ /** * gst_pad_get_caps_reffed: * @pad: a #GstPad to get the capabilities of. * * Gets the capabilities this pad can produce or consume. Preferred function if * one only wants to read or intersect the caps. * * Returns: the caps of the pad with incremented ref-count. * * Since: 0.10.26 */ GstCaps * gst_pad_get_caps_reffed (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_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 = gst_pad_get_caps_reffed (pad); /* be sure that we have a copy */ if (G_LIKELY (result)) result = gst_caps_make_writable (result); return result; } /* FIXME-0.11: what about making this the default and using * gst_caps_make_writable() explicitely where needed */ /** * gst_pad_peer_get_caps_reffed: * @pad: a #GstPad to get the capabilities of. * * Gets the capabilities of the peer connected to this pad. Preferred function * if one only wants to read or intersect the caps. * * Returns: the caps of the pad with incremented ref-count. * * Since: 0.10.26 */ GstCaps * gst_pad_peer_get_caps_reffed (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_reffed (peerpad); gst_object_unref (peerpad); return result; no_peer: { GST_OBJECT_UNLOCK (pad); return NULL; } } /** * gst_pad_peer_get_caps: * @pad: a #GstPad to get the peer capabilities of. * * Gets the capabilities of the peer connected to this pad. Similar to * gst_pad_get_caps(). * * Returns: a newly allocated copy of the #GstCaps of the peer pad. 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 }; /* list could be empty */ if (gst_value_list_get_size (src) <= 0) return FALSE; 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, len; len = gst_value_array_get_size (src); g_value_init (dest, GST_TYPE_ARRAY); for (n = 0; n < len; 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; GstStructure *s; g_return_if_fail (GST_IS_PAD (pad)); g_return_if_fail (caps != NULL); g_return_if_fail (!gst_caps_is_empty (caps)); /* FIXME-0.11: do not allow fixating any-caps * g_return_if_fail (!gst_caps_is_any (caps)); */ if (gst_caps_is_fixed (caps) || gst_caps_is_any (caps)) return; fixatefunc = GST_PAD_FIXATECAPSFUNC (pad); if (fixatefunc) { fixatefunc (pad, caps); } /* default fixation */ gst_caps_truncate (caps); s = gst_caps_get_structure (caps, 0); 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 *allowed; gboolean result = FALSE; GST_DEBUG_OBJECT (pad, "caps %" GST_PTR_FORMAT, caps); allowed = gst_pad_get_caps_reffed (pad); if (!allowed) goto nothing_allowed; GST_DEBUG_OBJECT (pad, "allowed caps %" GST_PTR_FORMAT, allowed); result = gst_caps_can_intersect (allowed, caps); gst_caps_unref (allowed); 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); 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; } acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad); 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; gst_object_ref (peerpad); /* release lock before calling external methods but keep ref to pad */ GST_OBJECT_UNLOCK (pad); result = gst_pad_accept_caps (peerpad, caps); gst_object_unref (peerpad); 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 %p %" GST_PTR_FORMAT, caps, caps); GST_OBJECT_UNLOCK (pad); #if GLIB_CHECK_VERSION(2,26,0) g_object_notify_by_pspec ((GObject *) pad, pspec_caps); #else g_object_notify ((GObject *) pad, "caps"); #endif 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 %p %" GST_PTR_FORMAT " same as existing, updating ptr only", caps, 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) { gboolean res; /* See if pad accepts the caps */ if (!gst_caps_can_intersect (caps, gst_pad_get_pad_template_caps (pad))) 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) { gboolean res; if (dosetcaps) { /* See if pad accepts the caps */ if (!gst_pad_accept_caps (pad, caps)) goto not_accepted; 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_reffed (pad); peercaps = gst_pad_get_caps_reffed (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. Unref 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"); if ((*buf = gst_buffer_try_new_and_alloc (size))) { GST_BUFFER_OFFSET (*buf) = offset; gst_buffer_set_caps (*buf, caps); return GST_FLOW_OK; } else { GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "out of memory allocating %d bytes", size); return GST_FLOW_ERROR; } } } /* FIXME 0.11: size should be unsigned */ static GstFlowReturn gst_pad_alloc_buffer_full (GstPad * pad, guint64 offset, gint size, GstCaps * caps, GstBuffer ** buf, gboolean setcaps) { GstPad *peer; GstFlowReturn ret; GstCaps *newcaps; 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); g_return_val_if_fail (size >= 0, GST_FLOW_ERROR); GST_DEBUG_OBJECT (pad, "offset %" G_GUINT64_FORMAT ", size %d, caps %" GST_PTR_FORMAT, offset, size, caps); 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? */ newcaps = 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 = newcaps && newcaps != 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 from %" GST_PTR_FORMAT " to %p %" GST_PTR_FORMAT, GST_PAD_CAPS (pad), newcaps, newcaps); if (G_UNLIKELY (!gst_pad_configure_src (pad, newcaps, setcaps))) goto not_negotiated; } /* sanity check (only if caps are the same) */ if (G_LIKELY (newcaps == caps) && G_UNLIKELY (GST_BUFFER_SIZE (*buf) < size)) goto wrong_size_fallback; 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; } wrong_size_fallback: { GST_CAT_ERROR_OBJECT (GST_CAT_PADS, pad, "buffer returned by alloc " "function is too small (%u < %d), doing fallback buffer alloc", GST_BUFFER_SIZE (*buf), size); gst_buffer_unref (*buf); if ((*buf = gst_buffer_try_new_and_alloc (size))) { GST_BUFFER_OFFSET (*buf) = offset; gst_buffer_set_caps (*buf, caps); return GST_FLOW_OK; } else { GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "out of memory allocating %d bytes", size); return GST_FLOW_ERROR; } } } /** * 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. If the caps changed, it is * possible that the buffer returned in @buf is not of the right size for the * new format, @buf needs to be unreffed and reallocated if this is the case. * * 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. */ /* FIXME 0.11: size should be unsigned */ 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. * * After a renegotiation, the size of the new buffer returned in @buf could * be of the wrong size for the new format and must be unreffed an reallocated * in that case. * * 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. */ /* FIXME 0.11: size should be unsigned */ 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); } #ifndef GST_REMOVE_DEPRECATED typedef struct { GList *list; guint32 cookie; } IntLinkIterData; static void int_link_iter_data_free (IntLinkIterData * data) { g_list_free (data->list); g_slice_free (IntLinkIterData, data); } #endif static GstIteratorItem iterate_pad (GstIterator * it, GstPad * pad) { gst_object_ref (pad); return GST_ITERATOR_ITEM_PASS; } /** * gst_pad_iterate_internal_links_default: * @pad: the #GstPad to get the internal links of. * * Iterate the list of pads to which the given pad is linked to inside of * the parent element. * This is the default handler, and thus returns an iterator of all of the * pads inside the parent element with opposite direction. * * The caller must free this iterator after use with gst_iterator_free(). * * Returns: a #GstIterator of #GstPad, or NULL if @pad has no parent. Unref each * returned pad with gst_object_unref(). * * Since: 0.10.21 */ GstIterator * gst_pad_iterate_internal_links_default (GstPad * pad) { GstIterator *res; GList **padlist; guint32 *cookie; GMutex *lock; gpointer owner; GstIteratorDisposeFunction dispose; g_return_val_if_fail (GST_IS_PAD (pad), NULL); #ifndef GST_REMOVE_DEPRECATED /* when we get here, the default handler for the iterate links is called, * which means that the user has not installed a custom one. We first check if * there is maybe a custom legacy function we can call. */ if (GST_PAD_INTLINKFUNC (pad) && GST_PAD_INTLINKFUNC (pad) != gst_pad_get_internal_links_default) { IntLinkIterData *data; /* make an iterator for the list. We can't protect the list with a * cookie. If we would take the cookie of the parent element, we need to * have a parent, which is not required for GST_PAD_INTLINKFUNC(). We could * cache the per-pad list and invalidate the list when a new call to * INTLINKFUNC() returned a different list but then this would only work if * two concurrent iterators were used and the last iterator would still be * thread-unsafe. Just don't use this method anymore. */ data = g_slice_new (IntLinkIterData); data->list = GST_PAD_INTLINKFUNC (pad) (pad); data->cookie = 0; GST_WARNING_OBJECT (pad, "Making unsafe iterator"); cookie = &data->cookie; padlist = &data->list; owner = data; dispose = (GstIteratorDisposeFunction) int_link_iter_data_free; /* reuse the pad lock, it's all we have here */ lock = GST_OBJECT_GET_LOCK (pad); } else #endif { GstElement *parent; GST_OBJECT_LOCK (pad); parent = GST_PAD_PARENT (pad); if (!parent || !GST_IS_ELEMENT (parent)) goto no_parent; gst_object_ref (parent); GST_OBJECT_UNLOCK (pad); if (pad->direction == GST_PAD_SRC) padlist = &parent->sinkpads; else padlist = &parent->srcpads; GST_DEBUG_OBJECT (pad, "Making iterator"); cookie = &parent->pads_cookie; owner = parent; dispose = (GstIteratorDisposeFunction) gst_object_unref; lock = GST_OBJECT_GET_LOCK (parent); } res = gst_iterator_new_list (GST_TYPE_PAD, lock, cookie, padlist, owner, (GstIteratorItemFunction) iterate_pad, dispose); return res; /* ERRORS */ no_parent: { GST_OBJECT_UNLOCK (pad); GST_DEBUG_OBJECT (pad, "no parent element"); return NULL; } } /** * gst_pad_iterate_internal_links: * @pad: the GstPad to get the internal links of. * * Gets an iterator for the pads to which the given pad is linked to inside * of the parent element. * * Each #GstPad element yielded by the iterator will have its refcount increased, * so unref after use. * * Returns: a new #GstIterator of #GstPad or %NULL when the pad does not have an * iterator function configured. Use gst_iterator_free() after usage. * * Since: 0.10.21 */ GstIterator * gst_pad_iterate_internal_links (GstPad * pad) { GstIterator *res = NULL; g_return_val_if_fail (GST_IS_PAD (pad), NULL); if (GST_PAD_ITERINTLINKFUNC (pad)) res = GST_PAD_ITERINTLINKFUNC (pad) (pad); return res; } #ifndef GST_REMOVE_DEPRECATED static void add_unref_pad_to_list (GstPad * pad, GList ** list) { *list = g_list_prepend (*list, pad); gst_object_unref (pad); } #endif /** * 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 with g_list_free(). * * Returns: a newly allocated #GList of pads, or NULL if the pad has no parent. * * Not MT safe. * * Deprecated: This function does not ref the pads in the list so that they * could become invalid by the time the application accesses them. It's also * possible that the list changes while handling the pads, which the caller of * this function is unable to know. Use the thread-safe * gst_pad_iterate_internal_links_default() instead. */ #ifndef GST_REMOVE_DEPRECATED GList * gst_pad_get_internal_links_default (GstPad * pad) { GList *res = NULL; GstElement *parent; g_return_val_if_fail (GST_IS_PAD (pad), NULL); GST_WARNING_OBJECT (pad, "Unsafe internal links used"); /* when we get here, the default handler for get_internal_links is called, * which means that the user has not installed a custom one. We first check if * there is maybe a custom iterate function we can call. */ if (GST_PAD_ITERINTLINKFUNC (pad) && GST_PAD_ITERINTLINKFUNC (pad) != gst_pad_iterate_internal_links_default) { GstIterator *it; GstIteratorResult ires; gboolean done = FALSE; it = gst_pad_iterate_internal_links (pad); /* loop over the iterator and put all elements into a list, we also * immediatly unref them, which is bad. */ do { ires = gst_iterator_foreach (it, (GFunc) add_unref_pad_to_list, &res); switch (ires) { case GST_ITERATOR_OK: case GST_ITERATOR_DONE: case GST_ITERATOR_ERROR: done = TRUE; break; case GST_ITERATOR_RESYNC: /* restart, discard previous list */ gst_iterator_resync (it); g_list_free (res); res = NULL; break; } } while (!done); gst_iterator_free (it); } else { /* lock pad, check and ref parent */ GST_OBJECT_LOCK (pad); parent = GST_PAD_PARENT (pad); if (!parent || !GST_IS_ELEMENT (parent)) goto no_parent; parent = gst_object_ref (parent); GST_OBJECT_UNLOCK (pad); /* now lock the parent while we copy the pads */ GST_OBJECT_LOCK (parent); if (pad->direction == GST_PAD_SRC) res = g_list_copy (parent->sinkpads); else res = g_list_copy (parent->srcpads); GST_OBJECT_UNLOCK (parent); gst_object_unref (parent); } /* At this point pads can be changed and unreffed. Nothing we can do about it * because for compatibility reasons this function cannot ref the pads or * notify the app that the list changed. */ return res; no_parent: { GST_DEBUG_OBJECT (pad, "no parent"); GST_OBJECT_UNLOCK (pad); return NULL; } } #endif /* GST_REMOVE_DEPRECATED */ /** * 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. * * Not MT safe. * * Returns: a newly allocated #GList of pads, free with g_list_free(). * * Deprecated: This function does not ref the pads in the list so that they * could become invalid by the time the application accesses them. It's also * possible that the list changes while handling the pads, which the caller of * this function is unable to know. Use the thread-safe * gst_pad_iterate_internal_links() instead. */ #ifndef GST_REMOVE_DEPRECATED #ifdef GST_DISABLE_DEPRECATED GList *gst_pad_get_internal_links (GstPad * pad); #endif GList * gst_pad_get_internal_links (GstPad * pad) { GList *res = NULL; g_return_val_if_fail (GST_IS_PAD (pad), NULL); GST_WARNING_OBJECT (pad, "Calling unsafe internal links"); if (GST_PAD_INTLINKFUNC (pad)) res = GST_PAD_INTLINKFUNC (pad) (pad); return res; } #endif /* GST_REMOVE_DEPRECATED */ static gboolean gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event) { gboolean result = FALSE; GstIterator *iter; gboolean done = FALSE; gpointer item; GstPad *eventpad; GList *pushed_pads = NULL; GST_INFO_OBJECT (pad, "Sending event %p (%s) to all internally linked pads", event, GST_EVENT_TYPE_NAME (event)); iter = gst_pad_iterate_internal_links (pad); if (!iter) goto no_iter; while (!done) { switch (gst_iterator_next (iter, &item)) { case GST_ITERATOR_OK: eventpad = GST_PAD_CAST (item); /* if already pushed, skip */ if (g_list_find (pushed_pads, eventpad)) { gst_object_unref (item); break; } if (GST_PAD_IS_SRC (eventpad)) { /* 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); result |= 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); done = TRUE; event = NULL; } pushed_pads = g_list_prepend (pushed_pads, eventpad); gst_object_unref (item); break; case GST_ITERATOR_RESYNC: /* FIXME, if we want to reset the result value we need to remember which * pads pushed with which result */ gst_iterator_resync (iter); break; case GST_ITERATOR_ERROR: GST_ERROR_OBJECT (pad, "Could not iterate over internally linked pads"); done = TRUE; break; case GST_ITERATOR_DONE: done = TRUE; break; } } gst_iterator_free (iter); no_iter: /* If this is a sinkpad and we don't have pads to send the event to, we * return TRUE. This is so that when using the default handler on a sink * element, we don't fail to push it. */ if (!pushed_pads) result = GST_PAD_IS_SINK (pad); g_list_free (pushed_pads); /* we handled the incoming event so we unref once */ if (event) { GST_LOG_OBJECT (pad, "handled event %p, unreffing", event); gst_event_unref (event); } 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); GST_LOG_OBJECT (pad, "default event handler"); switch (GST_EVENT_TYPE (event)) { case GST_EVENT_EOS: { GST_DEBUG_OBJECT (pad, "pausing task because of eos"); gst_pad_pause_task (pad); } /* fall thru */ default: break; } return gst_pad_event_default_dispatch (pad, event); } /** * gst_pad_dispatcher: * @pad: a #GstPad to dispatch. * @dispatch: the #GstPadDispatcherFunction 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; GstIterator *iter = NULL; gboolean done = FALSE; gpointer item; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); g_return_val_if_fail (dispatch != NULL, FALSE); iter = gst_pad_iterate_internal_links (pad); if (!iter) goto no_iter; while (!done) { switch (gst_iterator_next (iter, &item)) { case GST_ITERATOR_OK: { GstPad *int_pad = GST_PAD_CAST (item); GstPad *int_peer = gst_pad_get_peer (int_pad); if (int_peer) { GST_DEBUG_OBJECT (int_pad, "dispatching to peer %s:%s", GST_DEBUG_PAD_NAME (int_peer)); done = res = dispatch (int_peer, data); gst_object_unref (int_peer); } else { GST_DEBUG_OBJECT (int_pad, "no peer"); } } gst_object_unref (item); break; case GST_ITERATOR_RESYNC: gst_iterator_resync (iter); break; case GST_ITERATOR_ERROR: done = TRUE; GST_ERROR_OBJECT (pad, "Could not iterate internally linked pads"); break; case GST_ITERATOR_DONE: done = TRUE; break; } } gst_iterator_free (iter); GST_DEBUG_OBJECT (pad, "done, result %d", res); no_iter: 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_peer_query: * @pad: a #GstPad to invoke the peer query on. * @query: the #GstQuery to perform. * * Performs gst_pad_query() on the peer of @pad. * * The caller is responsible for both the allocation and deallocation of * the query structure. * * Returns: TRUE if the query could be performed. This function returns %FALSE * if @pad has no peer. * * Since: 0.10.15 */ gboolean gst_pad_peer_query (GstPad * pad, GstQuery * query) { GstPad *peerpad; gboolean result; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); g_return_val_if_fail (GST_IS_QUERY (query), FALSE); GST_OBJECT_LOCK (pad); GST_DEBUG_OBJECT (pad, "peer query"); peerpad = GST_PAD_PEER (pad); if (G_UNLIKELY (peerpad == NULL)) goto no_peer; gst_object_ref (peerpad); GST_OBJECT_UNLOCK (pad); result = gst_pad_query (peerpad, query); gst_object_unref (peerpad); return result; /* ERRORS */ no_peer: { GST_WARNING_OBJECT (pad, "pad has no peer"); GST_OBJECT_UNLOCK (pad); 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); } } #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED) /* 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; GstPadTemplate *tmpl; 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_static_pad (GST_ELEMENT (parent), name); if ((!pad) || ((tmpl = gst_pad_get_pad_template (pad)) && (GST_PAD_REQUEST == GST_PAD_TEMPLATE_PRESENCE (tmpl)))) pad = gst_element_get_request_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_static_pad (target, split[1]); if (!targetpad) targetpad = gst_element_get_request_pad (target, split[1]); if (targetpad == NULL) goto cleanup; if (gst_pad_get_direction (pad) == GST_PAD_SRC) gst_pad_link (pad, targetpad); else gst_pad_link (targetpad, pad); 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_CAST (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 performs 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 useful 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); while (GST_PAD_IS_BLOCKED (pad)) { do { /* we either have a callback installed to notify the block or * some other thread is doing a GCond wait. */ callback = pad->block_callback; pad->abidata.ABI.block_callback_called = TRUE; 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); } } while (pad->abidata.ABI.block_callback_called == FALSE && GST_PAD_IS_BLOCKED (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. */ if (!GST_PAD_IS_BLOCKED (pad)) break; /* 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); 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; } static void gst_pad_data_unref (gboolean is_buffer, void *data) { if (G_LIKELY (is_buffer)) { gst_buffer_unref (data); } else { gst_buffer_list_unref (data); } } static GstCaps * gst_pad_data_get_caps (gboolean is_buffer, void *data) { GstCaps *caps; if (G_LIKELY (is_buffer)) { caps = GST_BUFFER_CAPS (data); } else { GstBuffer *buf; if ((buf = gst_buffer_list_get (GST_BUFFER_LIST_CAST (data), 0, 0))) caps = GST_BUFFER_CAPS (buf); else caps = NULL; } return caps; } /* this is the chain function that does not perform the additional argument * checking for that little extra speed. */ static inline GstFlowReturn gst_pad_chain_data_unchecked (GstPad * pad, gboolean is_buffer, void *data) { GstCaps *caps; gboolean caps_changed; 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_pad_data_get_caps (is_buffer, data); 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 (G_LIKELY (is_buffer)) { if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (data))) goto dropping; } else { /* chain all groups in the buffer list one by one to avoid problems with * buffer probes that push buffers or events */ goto chain_groups; } } /* 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_LIKELY (is_buffer)) { GstPadChainFunction chainfunc; 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, GST_BUFFER_CAST (data)); GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "called chainfunction &%s, returned %s", GST_DEBUG_FUNCPTR_NAME (chainfunc), gst_flow_get_name (ret)); } else { GstPadChainListFunction chainlistfunc; if (G_UNLIKELY ((chainlistfunc = GST_PAD_CHAINLISTFUNC (pad)) == NULL)) goto chain_groups; GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "calling chainlistfunction &%s", GST_DEBUG_FUNCPTR_NAME (chainlistfunc)); ret = chainlistfunc (pad, GST_BUFFER_LIST_CAST (data)); GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "called chainlistfunction &%s, returned %s", GST_DEBUG_FUNCPTR_NAME (chainlistfunc), gst_flow_get_name (ret)); } GST_PAD_STREAM_UNLOCK (pad); return ret; chain_groups: { GstBufferList *list; GstBufferListIterator *it; GstBuffer *group; GST_PAD_STREAM_UNLOCK (pad); GST_INFO_OBJECT (pad, "chaining each group in list as a merged buffer"); list = GST_BUFFER_LIST_CAST (data); it = gst_buffer_list_iterate (list); if (gst_buffer_list_iterator_next_group (it)) { do { group = gst_buffer_list_iterator_merge_group (it); if (group == NULL) { group = gst_buffer_new (); GST_CAT_INFO_OBJECT (GST_CAT_SCHEDULING, pad, "chaining empty group"); } else { GST_CAT_INFO_OBJECT (GST_CAT_SCHEDULING, pad, "chaining group"); } ret = gst_pad_chain_data_unchecked (pad, TRUE, group); } while (ret == GST_FLOW_OK && gst_buffer_list_iterator_next_group (it)); } else { GST_CAT_INFO_OBJECT (GST_CAT_SCHEDULING, pad, "chaining empty group"); ret = gst_pad_chain_data_unchecked (pad, TRUE, gst_buffer_new ()); } gst_buffer_list_iterator_free (it); gst_buffer_list_unref (list); return ret; } /* ERRORS */ flushing: { gst_pad_data_unref (is_buffer, data); 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_pad_data_unref (is_buffer, data); GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return"); GST_PAD_STREAM_UNLOCK (pad); return GST_FLOW_OK; } not_negotiated: { gst_pad_data_unref (is_buffer, data); GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pushing data but pad did not accept"); GST_PAD_STREAM_UNLOCK (pad); return GST_FLOW_NOT_NEGOTIATED; } no_function: { gst_pad_data_unref (is_buffer, data); 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_IS_SINK (pad), GST_FLOW_ERROR); g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR); return gst_pad_chain_data_unchecked (pad, TRUE, buffer); } /** * gst_pad_chain_list: * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not. * @list: the #GstBufferList to send, return GST_FLOW_ERROR if not. * * Chain a bufferlist to @pad. * * The function returns #GST_FLOW_WRONG_STATE if the pad was flushing. * * If the caps on the first buffer of @list 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 chainlist function installed on @pad (see * gst_pad_set_chain_list_function()) and the return value of that function is * returned to the caller. #GST_FLOW_NOT_SUPPORTED is returned if @pad has no * chainlist function. * * In all cases, success or failure, the caller loses its reference to @list * after calling this function. * * MT safe. * * Returns: a #GstFlowReturn from the pad. * * Since: 0.10.24 */ GstFlowReturn gst_pad_chain_list (GstPad * pad, GstBufferList * list) { g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR); g_return_val_if_fail (GST_PAD_IS_SINK (pad), GST_FLOW_ERROR); g_return_val_if_fail (GST_IS_BUFFER_LIST (list), GST_FLOW_ERROR); return gst_pad_chain_data_unchecked (pad, FALSE, list); } static GstFlowReturn gst_pad_push_data (GstPad * pad, gboolean is_buffer, void *data) { GstPad *peer; GstFlowReturn ret; GstCaps *caps; gboolean caps_changed; 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 (G_LIKELY (is_buffer)) { /* 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 (data))) goto dropped; } else { /* push all buffers in the list */ goto push_groups; } GST_OBJECT_LOCK (pad); } if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL)) goto not_linked; /* Before pushing the buffer to the peer pad, ensure that caps * are set on this pad */ caps = gst_pad_data_get_caps (is_buffer, data); caps_changed = caps && caps != GST_PAD_CAPS (pad); /* take ref to peer pad before releasing the lock */ gst_object_ref (peer); 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 from %" GST_PTR_FORMAT " to %p %" GST_PTR_FORMAT, GST_PAD_CAPS (pad), caps, caps); if (G_UNLIKELY (!gst_pad_set_caps (pad, caps))) goto not_negotiated; } ret = gst_pad_chain_data_unchecked (peer, is_buffer, data); gst_object_unref (peer); return ret; push_groups: { GstBufferList *list; GstBufferListIterator *it; GstBuffer *group; GST_INFO_OBJECT (pad, "pushing each group in list as a merged buffer"); list = GST_BUFFER_LIST_CAST (data); it = gst_buffer_list_iterate (list); if (gst_buffer_list_iterator_next_group (it)) { do { group = gst_buffer_list_iterator_merge_group (it); if (group == NULL) { group = gst_buffer_new (); GST_CAT_INFO_OBJECT (GST_CAT_SCHEDULING, pad, "pushing empty group"); } else { GST_CAT_INFO_OBJECT (GST_CAT_SCHEDULING, pad, "pushing group"); } ret = gst_pad_push_data (pad, TRUE, group); } while (ret == GST_FLOW_OK && gst_buffer_list_iterator_next_group (it)); } else { GST_CAT_INFO_OBJECT (GST_CAT_SCHEDULING, pad, "pushing empty group"); ret = gst_pad_push_data (pad, TRUE, gst_buffer_new ()); } gst_buffer_list_iterator_free (it); gst_buffer_list_unref (list); return ret; } /* ERROR recovery here */ flushed: { gst_pad_data_unref (is_buffer, data); GST_DEBUG_OBJECT (pad, "pad block stopped by flush"); GST_OBJECT_UNLOCK (pad); return ret; } dropped: { gst_pad_data_unref (is_buffer, data); GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return"); return GST_FLOW_OK; } not_linked: { gst_pad_data_unref (is_buffer, data); 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_pad_data_unref (is_buffer, data); gst_object_unref (peer); GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad, "element pushed data then refused to accept the caps"); return GST_FLOW_NOT_NEGOTIATED; } } /** * 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) { 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 (GST_IS_BUFFER (buffer), GST_FLOW_ERROR); return gst_pad_push_data (pad, TRUE, buffer); } /** * gst_pad_push_list: * @pad: a source #GstPad, returns #GST_FLOW_ERROR if not. * @list: the #GstBufferList to push returns GST_FLOW_ERROR if not. * * Pushes a buffer list to the peer of @pad. * * This function will call an installed pad block before triggering any * installed pad probes. * * If the caps on the first buffer in the first group of @list 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. * * If there are any probes installed on @pad every group of the buffer list * will be merged into a normal #GstBuffer and pushed via gst_pad_push and the * buffer list will be unreffed. * * The function proceeds calling the chain function on the peer pad and returns * the value from that function. If @pad has no peer, #GST_FLOW_NOT_LINKED will * be returned. If the peer pad does not have any installed chainlist function * every group buffer of the list will be merged into a normal #GstBuffer and * chained via gst_pad_chain(). * * In all cases, success or failure, the caller loses its reference to @list * after calling this function. * * Returns: a #GstFlowReturn from the peer pad. * * MT safe. * * Since: 0.10.24 */ GstFlowReturn gst_pad_push_list (GstPad * pad, GstBufferList * list) { 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 (GST_IS_BUFFER_LIST (list), GST_FLOW_ERROR); return gst_pad_push_data (pad, FALSE, list); } /** * 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_IS_SINK (pad)) 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; GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "no checkgetrangefunc, assuming %d", ret); } 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; } } static GstFlowReturn gst_pad_get_range_unchecked (GstPad * pad, guint64 offset, guint size, GstBuffer ** buffer) { GstFlowReturn ret; GstPadGetRangeFunction getrangefunc; gboolean emit_signal; GstCaps *caps; gboolean caps_changed; 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_UNLIKELY (ret != GST_FLOW_OK)) goto get_range_failed; 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); if (G_UNLIKELY (caps_changed)) { GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps); /* this should usually work because the element produced the buffer */ if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE))) 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; } get_range_failed: { *buffer = NULL; GST_CAT_LEVEL_LOG (GST_CAT_SCHEDULING, (ret >= GST_FLOW_UNEXPECTED) ? GST_LEVEL_INFO : GST_LEVEL_WARNING, pad, "getrange failed, flow: %s", gst_flow_get_name (ret)); return ret; } not_negotiated: { gst_buffer_unref (*buffer); *buffer = NULL; GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad, "getrange returned buffer of unaccaptable caps"); return GST_FLOW_NOT_NEGOTIATED; } } /** * 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 and @buffer is %NULL. * * 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. * * This is a lowlevel function. Usualy gst_pad_pull_range() is used. * * Returns: a #GstFlowReturn from the pad. * * MT safe. */ GstFlowReturn gst_pad_get_range (GstPad * pad, guint64 offset, guint size, GstBuffer ** buffer) { 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 (buffer != NULL, GST_FLOW_ERROR); return gst_pad_get_range_unchecked (pad, offset, size, buffer); } /** * 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; GstCaps *caps; gboolean caps_changed; g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR); g_return_val_if_fail (GST_PAD_IS_SINK (pad), 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_unchecked (peer, offset, size, buffer); gst_object_unref (peer); if (G_UNLIKELY (ret != GST_FLOW_OK)) goto pull_range_failed; /* can only fire the signal if we have a valid buffer */ if (G_UNLIKELY (emit_signal)) { if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer))) goto dropping; } 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)) { 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; } 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; } pull_range_failed: { *buffer = NULL; GST_CAT_LEVEL_LOG (GST_CAT_SCHEDULING, (ret >= GST_FLOW_UNEXPECTED) ? GST_LEVEL_INFO : GST_LEVEL_WARNING, pad, "pullrange failed, flow: %s", gst_flow_get_name (ret)); return ret; } 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 ", result %d", peerpad, result); 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: if (G_LIKELY (GST_PAD_ACTIVATE_MODE (pad) != GST_ACTIVATE_NONE)) { 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); GST_DEBUG_OBJECT (pad, "sent event, result %d", result); 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); if (need_unlock) GST_PAD_STREAM_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; } static void do_stream_status (GstPad * pad, GstStreamStatusType type, GThread * thread, GstTask * task) { GstElement *parent; GST_DEBUG_OBJECT (pad, "doing stream-status %d", type); if ((parent = GST_ELEMENT_CAST (gst_pad_get_parent (pad)))) { if (GST_IS_ELEMENT (parent)) { GstMessage *message; GValue value = { 0 }; if (type == GST_STREAM_STATUS_TYPE_ENTER) { gchar *tname, *ename, *pname; /* create a good task name */ ename = gst_element_get_name (parent); pname = gst_pad_get_name (pad); tname = g_strdup_printf ("%s:%s", ename, pname); g_free (ename); g_free (pname); gst_object_set_name (GST_OBJECT_CAST (task), tname); g_free (tname); } message = gst_message_new_stream_status (GST_OBJECT_CAST (pad), type, parent); g_value_init (&value, GST_TYPE_TASK); g_value_set_object (&value, task); gst_message_set_stream_status_object (message, &value); g_value_unset (&value); GST_DEBUG_OBJECT (pad, "posting stream-status %d", type); gst_element_post_message (parent, message); } gst_object_unref (parent); } } static void pad_enter_thread (GstTask * task, GThread * thread, gpointer user_data) { do_stream_status (GST_PAD_CAST (user_data), GST_STREAM_STATUS_TYPE_ENTER, thread, task); } static void pad_leave_thread (GstTask * task, GThread * thread, gpointer user_data) { do_stream_status (GST_PAD_CAST (user_data), GST_STREAM_STATUS_TYPE_LEAVE, thread, task); } static GstTaskThreadCallbacks thr_callbacks = { pad_enter_thread, pad_leave_thread, }; /** * 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 repeatedly calls @func with @data. This function * is mostly used in pad activation functions to start the dataflow. * The #GST_PAD_STREAM_LOCK of @pad will automatically be acquired * before @func is called. * * Returns: a %TRUE if the task could be started. */ gboolean gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data) { GstTask *task; gboolean res; 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_task_set_thread_callbacks (task, &thr_callbacks, pad, NULL); GST_DEBUG_OBJECT (pad, "created task"); GST_PAD_TASK (pad) = task; gst_object_ref (task); /* release lock to post the message */ GST_OBJECT_UNLOCK (pad); do_stream_status (pad, GST_STREAM_STATUS_TYPE_CREATE, NULL, task); gst_object_unref (task); GST_OBJECT_LOCK (pad); /* nobody else is supposed to have changed the pad now */ if (GST_PAD_TASK (pad) != task) goto concurrent_stop; } res = gst_task_set_state (task, GST_TASK_STARTED); GST_OBJECT_UNLOCK (pad); return res; /* ERRORS */ concurrent_stop: { 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 wait until the * function executed by the task is finished if this function is not * called from the task function. * * 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; gboolean res; 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; res = gst_task_set_state (task, GST_TASK_PAUSED); GST_OBJECT_UNLOCK (pad); /* wait for task function to finish, this lock is recursive so it does nothing * when the pause is called from the task itself */ GST_PAD_STREAM_LOCK (pad); GST_PAD_STREAM_UNLOCK (pad); return res; 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; gboolean res; 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; res = gst_task_set_state (task, GST_TASK_STOPPED); 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 res; 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; } }