/* 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 */ }; typedef struct _GstPadPushCache GstPadPushCache; struct _GstPadPushCache { GstPad *peer; /* reffed peer pad */ }; static GstPadPushCache _pad_cache_invalid = { NULL, }; #define PAD_CACHE_INVALID (&_pad_cache_invalid) #define GST_PAD_GET_PRIVATE(obj) \ (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_PAD, GstPadPrivate)) /* we have a pending and an active event on the pad. On source pads only the * active event is used. On sinkpads, events are copied to the pending entry and * moved to the active event when the eventfunc returned TRUE. */ typedef struct { GstEvent *pending; GstEvent *event; } PadEvent; struct _GstPadPrivate { GstPadPushCache *cache_ptr; PadEvent events[GST_EVENT_MAX_STICKY]; }; 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, GstCaps * filter); 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); 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, G_TYPE_POINTER); 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)); 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); 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->priv = GST_PAD_GET_PRIVATE (pad); GST_PAD_DIRECTION (pad) = GST_PAD_UNKNOWN; 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; GST_PAD_ITERINTLINKFUNC (pad) = gst_pad_iterate_internal_links_default; GST_PAD_ACCEPTCAPSFUNC (pad) = gst_pad_acceptcaps_default; GST_PAD_SET_FLUSHING (pad); /* 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 (); } /* called when setting the pad inactive. It removes all sticky events from * the pad */ static void clear_events (PadEvent events[]) { guint i; for (i = 0; i < GST_EVENT_MAX_STICKY; i++) { gst_event_replace (&events[i].event, NULL); gst_event_replace (&events[i].pending, NULL); } } /* The sticky event with @idx from the srcpad is copied to the * pending event on the sinkpad (when different). * This function applies the pad offsets in case of segment events. * This will make sure that we send the event to the sinkpad event * function when the next buffer of event arrives. * Should be called with the OBJECT lock of both pads. * This function returns TRUE when there is a pending event on the * sinkpad */ static gboolean replace_event (GstPad * srcpad, GstPad * sinkpad, guint idx) { PadEvent *srcev, *sinkev; GstEvent *event; gboolean pending = FALSE; srcev = &srcpad->priv->events[idx]; if ((event = srcev->event)) { sinkev = &sinkpad->priv->events[idx]; switch (GST_EVENT_TYPE (event)) { case GST_EVENT_SEGMENT: { GstSegment segment; gint64 offset; offset = srcpad->offset + sinkpad->offset; if (offset != 0) { gst_event_copy_segment (event, &segment); /* adjust the base time. FIXME, check negative times, try to tweak the * start to do clipping on negative times */ segment.base += offset; /* make a new event from the updated segment */ event = gst_event_new_segment (&segment); } break; } default: break; } if (sinkev->event != event) { /* put in the pending entry when different */ gst_event_replace (&sinkev->pending, event); pending = TRUE; } } return pending; } /* should be called with the OBJECT_LOCK */ static GstCaps * get_pad_caps (GstPad * pad) { GstCaps *caps = NULL; GstEvent *event; guint idx; idx = GST_EVENT_STICKY_IDX_TYPE (GST_EVENT_CAPS); /* we can only use the caps when we have successfully send the caps * event to the event function and is thus in the active entry */ if ((event = pad->priv->events[idx].event)) gst_event_parse_caps (event, &caps); return caps; } 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); } 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; } clear_events (pad->priv->events); 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->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, get_pad_caps (GST_PAD_CAST (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: (transfer full): 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: (transfer full): 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: (transfer full): 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"); _priv_gst_pad_invalidate_cache (pad); 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_OBJECT_LOCK (pad); clear_events (pad->priv->events); GST_OBJECT_UNLOCK (pad); GST_PAD_STREAM_UNLOCK (pad); break; } } /** * gst_pad_set_active: * @pad: the #GstPad to activate or deactivate. * @active: whether or not the pad should be active. * * Activates or deactivates the given pad. * Normally called from within core state change functions. * * If @active, makes sure the pad is active. If it is already active, either in * push or pull mode, just return. Otherwise dispatches to the pad's activate * function to perform the actual activation. * * If not @active, checks the pad's current mode and calls * gst_pad_activate_push() or gst_pad_activate_pull(), as appropriate, with a * FALSE argument. * * Returns: #TRUE if the operation was successful. * * MT safe. */ gboolean gst_pad_set_active (GstPad * pad, gboolean active) { GstActivateMode old; gboolean ret = FALSE; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); GST_OBJECT_LOCK (pad); old = GST_PAD_ACTIVATE_MODE (pad); GST_OBJECT_UNLOCK (pad); if (active) { switch (old) { case GST_ACTIVATE_PUSH: 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; default: GST_DEBUG_OBJECT (pad, "unknown activation mode!"); 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; default: GST_DEBUG_OBJECT (pad, "unknown activation mode!"); 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); } else { if (!active) { GST_OBJECT_LOCK (pad); GST_OBJECT_FLAG_UNSET (pad, GST_PAD_NEED_RECONFIGURE); 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"); _priv_gst_pad_invalidate_cache (pad); 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"); _priv_gst_pad_invalidate_cache (pad); 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: (closure): 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. * * * Pad block handlers are only called for source pads in push mode * and sink pads in pull mode. * * * 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"); _priv_gst_pad_invalidate_cache (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->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->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: (closure): 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. * * * Pad block handlers are only called for source pads in push mode * and sink pads in pull mode. * * * 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. * * * Pad blocks are only possible for source pads in push mode * and sink pads in pull mode. * * * 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: (transfer none) (array zero-terminated=1): 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: (transfer none) (array zero-terminated=1): a 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_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_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; gint i; 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); } _priv_gst_pad_invalidate_cache (srcpad); /* first clear peers */ GST_PAD_PEER (srcpad) = NULL; GST_PAD_PEER (sinkpad) = NULL; /* clear pending caps if any */ for (i = 0; i < GST_EVENT_MAX_STICKY; i++) gst_event_replace (&sinkpad->priv->events[i].pending, 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, NULL); sinkcaps = gst_pad_get_caps_unlocked (sink, NULL); } 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; guint i; gboolean pending; 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; /* make sure we push the events from the source to this new peer, for this we * copy the events on the sinkpad and mark EVENTS_PENDING */ pending = FALSE; for (i = 0; i < GST_EVENT_MAX_STICKY; i++) pending |= replace_event (srcpad, sinkpad, i); /* we had some new pending events, set our flag */ if (pending) GST_OBJECT_FLAG_SET (sinkpad, GST_PAD_NEED_EVENTS); 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)); gst_pad_send_event (srcpad, gst_event_new_reconfigure ()); } 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: (transfer full): the #GstPadTemplate from which this pad was * instantiated, or %NULL if this pad has no template. Unref after * usage. */ GstPadTemplate * gst_pad_get_pad_template (GstPad * pad) { GstPadTemplate *templ; g_return_val_if_fail (GST_IS_PAD (pad), NULL); templ = GST_PAD_PAD_TEMPLATE (pad); return (templ ? gst_object_ref (templ) : NULL); } /* 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 * filter) { GstCaps *result = NULL; GstPadTemplate *templ; gboolean fixed_caps; GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps"); fixed_caps = GST_PAD_IS_FIXED_CAPS (pad); if (!fixed_caps && GST_PAD_GETCAPSFUNC (pad)) { GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "dispatching to pad getcaps function with " "filter %" GST_PTR_FORMAT, filter); GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS); GST_OBJECT_UNLOCK (pad); result = GST_PAD_GETCAPSFUNC (pad) (pad, filter); 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; } } if (filter) { if (!gst_caps_is_subset (result, filter)) { GstCaps *temp; GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad, "pad returned caps %" GST_PTR_FORMAT " which are not a real subset of the filter caps %" GST_PTR_FORMAT, result, filter); g_warning ("pad %s:%s returned caps which are not a real " "subset of the filter caps", GST_DEBUG_PAD_NAME (pad)); /* FIXME: Order? But shouldn't happen anyway... */ temp = gst_caps_intersect_full (filter, result, GST_CAPS_INTERSECT_FIRST); gst_caps_unref (result); result = temp; } } #endif goto done; } } if (fixed_caps && (result = get_pad_caps (pad))) { if (filter) { GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "using pad caps %p %" GST_PTR_FORMAT " with filter %p %" GST_PTR_FORMAT, result, result, filter, filter); result = gst_caps_intersect_full (filter, result, GST_CAPS_INTERSECT_FIRST); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "result %p %" GST_PTR_FORMAT, result); } else { GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "using pad caps %p %" GST_PTR_FORMAT, result, result); result = gst_caps_ref (result); } goto done; } if ((templ = GST_PAD_PAD_TEMPLATE (pad))) { result = GST_PAD_TEMPLATE_CAPS (templ); if (filter) { GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "using pad template %p with caps %p %" GST_PTR_FORMAT " and filter %p %" GST_PTR_FORMAT, templ, result, result, filter, filter); result = gst_caps_intersect_full (filter, result, GST_CAPS_INTERSECT_FIRST); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "result %p %" GST_PTR_FORMAT, result); } else { 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 (!fixed_caps && (result = get_pad_caps (pad))) { if (filter) { GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "using pad caps %p %" GST_PTR_FORMAT " with filter %p %" GST_PTR_FORMAT, result, result, filter, filter); result = gst_caps_intersect_full (filter, result, GST_CAPS_INTERSECT_FIRST); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "result %p %" GST_PTR_FORMAT, result); } else { 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; } /** * gst_pad_has_current_caps: * @pad: a #GstPad to check * * Check if @pad has caps set on it with gst_pad_set_caps(). * * Returns: TRUE when @pad has caps associated with it. */ gboolean gst_pad_has_current_caps (GstPad * pad) { gboolean result; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); GST_OBJECT_LOCK (pad); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "check current pad caps"); result = (get_pad_caps (pad) != NULL); GST_OBJECT_UNLOCK (pad); return result; } /** * gst_pad_get_current_caps: * @pad: a #GstPad to get the current capabilities of. * * Gets the capabilities currently configured on @pad with the last call to * gst_pad_set_caps(). * * Returns: the current caps of the pad with incremented ref-count. */ GstCaps * gst_pad_get_current_caps (GstPad * pad) { GstCaps *result; g_return_val_if_fail (GST_IS_PAD (pad), NULL); GST_OBJECT_LOCK (pad); if ((result = get_pad_caps (pad))) gst_caps_ref (result); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get current pad caps %" GST_PTR_FORMAT, result); GST_OBJECT_UNLOCK (pad); return result; } /** * gst_pad_get_caps: * @pad: a #GstPad to get the capabilities of. * @filter: suggested #GstCaps. * * 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_get_current_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. * * When called on sinkpads @filter contains the caps that * upstream could produce in the order preferred by upstream. When * called on srcpads @filter contains the caps accepted by * downstream in the preffered order. @filter might be %NULL but * if it is not %NULL the returned caps will be a subset of @filter. * * Note that this function does not return writable #GstCaps, use * gst_caps_make_writable() before modifying the caps. * * Returns: the caps of the pad with incremented ref-count. */ GstCaps * gst_pad_get_caps (GstPad * pad, GstCaps * filter) { GstCaps *result = NULL; g_return_val_if_fail (GST_IS_PAD (pad), NULL); g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), NULL); GST_OBJECT_LOCK (pad); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps"); result = gst_pad_get_caps_unlocked (pad, filter); GST_OBJECT_UNLOCK (pad); return result; } /** * gst_pad_peer_get_caps: * @pad: a #GstPad to get the capabilities of. * @filter: a #GstCaps filter. * * Gets the capabilities of the peer connected to this pad. Similar to * gst_pad_get_caps(). * * When called on srcpads @filter contains the caps that * upstream could produce in the order preferred by upstream. When * called on sinkpads @filter contains the caps accepted by * downstream in the preffered order. @filter might be %NULL but * if it is not %NULL the returned caps will be a subset of @filter. * * Returns: the caps of the peer pad with incremented ref-count. This function * returns %NULL when there is no peer pad. */ GstCaps * gst_pad_peer_get_caps (GstPad * pad, GstCaps * filter) { GstPad *peerpad; GstCaps *result = NULL; g_return_val_if_fail (GST_IS_PAD (pad), NULL); g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), 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, filter); 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)); 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 (pad, NULL); 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; #if 0 GstCaps *existing = NULL; #endif 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); #if 0 /* 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; } #endif 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; #if 0 is_same_caps: { GST_DEBUG_OBJECT (pad, "pad had same caps"); GST_OBJECT_UNLOCK (pad); return TRUE; } #endif } /** * 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: (transfer none): 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) { GstEvent *event; gboolean res = TRUE; g_return_val_if_fail (GST_IS_PAD (pad), FALSE); g_return_val_if_fail (caps != NULL && gst_caps_is_fixed (caps), FALSE); event = gst_event_new_caps (caps); if (GST_PAD_IS_SRC (pad)) gst_pad_push_event (pad, event); else res = gst_pad_send_event (pad, event); return res; } static gboolean gst_pad_call_setcaps (GstPad * pad, GstCaps * caps) { GstPadSetCapsFunction setcaps; GST_OBJECT_LOCK (pad); setcaps = GST_PAD_SETCAPSFUNC (pad); /* call setcaps function to configure the pad only if the * caps is not NULL */ if (setcaps != NULL) { 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 setcaps_failed; 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_OBJECT_UNLOCK (pad); g_object_notify_by_pspec ((GObject *) pad, pspec_caps); return TRUE; /* ERRORS */ setcaps_failed: { return FALSE; } } static gboolean do_event_function (GstPad * pad, GstEvent * event, GstPadEventFunction eventfunc) { gboolean result = TRUE; GstCaps *caps, *templ; switch (GST_EVENT_TYPE (event)) { case GST_EVENT_CAPS: { /* backwards compatibility mode for caps */ gst_event_parse_caps (event, &caps); /* See if pad accepts the caps */ templ = gst_pad_get_pad_template_caps (pad); if (!gst_caps_can_intersect (caps, templ)) goto not_accepted; if (!gst_pad_call_setcaps (pad, caps)) goto not_accepted; gst_caps_unref (templ); break; } default: break; } GST_DEBUG_OBJECT (pad, "calling event function with event %p", event); result = eventfunc (pad, event); return result; /* ERRORS */ not_accepted: { gst_caps_unref (templ); gst_event_unref (event); GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "caps %" GST_PTR_FORMAT " not accepted", caps); return FALSE; } } /* function to send all pending events on the sinkpad to the event * function and collect the results. This function should be called with * the object lock. The object lock might be released by this function. */ static GstFlowReturn gst_pad_update_events (GstPad * pad) { GstFlowReturn ret = GST_FLOW_OK; guint i; GstPadEventFunction eventfunc; GstEvent *event; if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL)) goto no_function; restart: for (i = 0; i < GST_EVENT_MAX_STICKY; i++) { gboolean res; PadEvent *ev; ev = &pad->priv->events[i]; /* skip without pending event */ if ((event = ev->pending) == NULL) continue; gst_event_ref (event); GST_OBJECT_UNLOCK (pad); res = do_event_function (pad, event, eventfunc); GST_OBJECT_LOCK (pad); /* things could have changed while we release the lock, check if we still * are handling the same event, if we don't something changed and we have * to try again. FIXME. we need a cookie here. */ if (event != ev->pending) { GST_DEBUG_OBJECT (pad, "events changed, restarting"); goto restart; } /* remove the event from the pending entry in all cases */ ev->pending = NULL; if (res) { /* make the event active */ if (ev->event) gst_event_unref (ev->event); ev->event = event; } else { gst_event_unref (event); ret = GST_FLOW_ERROR; } } /* when we get here all events were successfully updated. */ return ret; /* ERRORS */ no_function: { g_warning ("pad %s:%s has no event handler, file a bug.", GST_DEBUG_PAD_NAME (pad)); return GST_FLOW_NOT_SUPPORTED; } } /** * gst_pad_get_pad_template_caps: * @pad: a #GstPad to get the template capabilities from. * * Gets the capabilities for @pad's template. * * Returns: (transfer full): the #GstCaps of this pad template. * Unref after usage. */ 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_get_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: (transfer full): 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: (transfer full): the allowed #GstCaps of the pad link. Unref the * caps when you no longer need it. This function returns NULL when @pad * has no peer. * * MT safe. */ GstCaps * gst_pad_get_allowed_caps (GstPad * pad) { GstCaps *mycaps; GstCaps *caps; GstCaps *peercaps; GstPad *peer; g_return_val_if_fail (GST_IS_PAD (pad), NULL); GST_OBJECT_LOCK (pad); peer = GST_PAD_PEER (pad); if (G_UNLIKELY (peer == NULL)) goto no_peer; GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting allowed caps"); gst_object_ref (peer); GST_OBJECT_UNLOCK (pad); mycaps = gst_pad_get_caps (pad, NULL); peercaps = gst_pad_get_caps (peer, NULL); 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: (transfer full): 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 = NULL; 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"); if ((caps = get_pad_caps (pad))) 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; } } /** * 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; g_return_val_if_fail (GST_IS_PAD (pad), NULL); { 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; lock = GST_OBJECT_GET_LOCK (parent); } res = gst_iterator_new_list (GST_TYPE_PAD, lock, cookie, padlist, (GObject *) owner, NULL); gst_object_unref (owner); 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. * * Free-function: gst_iterator_free * * Returns: (transfer full): 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; } static gboolean gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event) { gboolean result = FALSE; GstIterator *iter; gboolean done = FALSE; GValue item = { 0, }; 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 = g_value_get_object (&item); /* if already pushed, skip */ if (g_list_find (pushed_pads, eventpad)) { g_value_reset (&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); g_value_reset (&item); break; case GST_ITERATOR_RESYNC: /* We don't reset the result here because we don't push the event * again on pads that got the event already and because we need * to consider the result of the previous pushes */ 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; } } g_value_unset (&item); 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: (transfer full): 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) { gboolean result = TRUE, forward = TRUE; 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); break; } case GST_EVENT_CAPS: { /* don't forward by default */ forward = FALSE; break; } default: break; } if (forward) result = gst_pad_event_default_dispatch (pad, event); else gst_event_unref (event); return result; } /** * gst_pad_dispatcher: * @pad: a #GstPad to dispatch. * @dispatch: the #GstPadDispatcherFunction to call. * @data: (closure): 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; GValue item = { 0, }; 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 = g_value_get_object (&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"); } g_value_reset (&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; } } g_value_unset (&item); 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: (transfer none): 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. The element that * the pad belongs to 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. * * Please also note that some queries might need a running pipeline to work. * * 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: (transfer none): 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: (transfer none): 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); } } /* * 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 * 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->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->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; } } /* pad offsets */ /** * gst_pad_get_offset: * @pad: a #GstPad * * Get the offset applied to the running time of @pad. @pad has to be a source * pad. * * Returns: the offset. */ gint64 gst_pad_get_offset (GstPad * pad) { gint64 result; g_return_val_if_fail (GST_IS_PAD (pad), 0); GST_OBJECT_LOCK (pad); result = pad->offset; GST_OBJECT_UNLOCK (pad); return result; } /** * gst_pad_set_offset: * @pad: a #GstPad * @offset: the offset * * Set the offset that will be applied to the running time of @pad. */ void gst_pad_set_offset (GstPad * pad, gint64 offset) { guint idx; GstPad *peer; GstPad *tmp = NULL; g_return_if_fail (GST_IS_PAD (pad)); GST_OBJECT_LOCK (pad); /* if nothing changed, do nothing */ if (pad->offset == offset) goto done; pad->offset = offset; /* if no peer, we just updated the offset */ if ((peer = GST_PAD_PEER (pad)) == NULL) goto done; /* switch pads around when dealing with a sinkpad */ if (GST_PAD_IS_SINK (pad)) { /* ref the peer so it doesn't go away when we release the lock */ tmp = gst_object_ref (peer); /* make sure we get the peer (the srcpad) */ GST_OBJECT_UNLOCK (pad); /* swap pads */ peer = pad; pad = tmp; GST_OBJECT_LOCK (pad); /* check if the pad didn't get relinked */ if (GST_PAD_PEER (pad) != peer) goto done; /* we can release the ref now */ gst_object_unref (peer); } /* the index of the segment event in the array */ idx = GST_EVENT_STICKY_IDX_TYPE (GST_EVENT_SEGMENT); /* lock order is srcpad >> sinkpad */ GST_OBJECT_LOCK (peer); /* take the current segment event, adjust it and then place * it on the sinkpad. events on the srcpad are always active. */ if (replace_event (pad, peer, idx)) GST_OBJECT_FLAG_SET (peer, GST_PAD_NEED_EVENTS); GST_OBJECT_UNLOCK (peer); done: GST_OBJECT_UNLOCK (pad); } /********************************************************************** * 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_MINI_OBJECT_TYPE (obj)); g_value_set_boxed (&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); } } /* 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, GstPadPushCache * cache) { gboolean needs_events; GstFlowReturn ret; gboolean emit_signal; GST_PAD_STREAM_LOCK (pad); GST_OBJECT_LOCK (pad); if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad))) goto flushing; needs_events = GST_PAD_NEEDS_EVENTS (pad); if (G_UNLIKELY (needs_events)) { GST_OBJECT_FLAG_UNSET (pad, GST_PAD_NEED_EVENTS); GST_DEBUG_OBJECT (pad, "need to update all events"); ret = gst_pad_update_events (pad); if (G_UNLIKELY (ret != GST_FLOW_OK)) goto events_error; } emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0; GST_OBJECT_UNLOCK (pad); /* see if the signal should be emited */ if (G_UNLIKELY (emit_signal)) { cache = NULL; if (G_LIKELY (is_buffer)) { if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT_CAST (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; } } /* 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 with buffer %p", GST_DEBUG_FUNCPTR_NAME (chainfunc), data); if (cache) { cache->peer = gst_object_ref (pad); } ret = chainfunc (pad, GST_BUFFER_CAST (data)); GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "called chainfunction &%s with buffer %p, returned %s", GST_DEBUG_FUNCPTR_NAME (chainfunc), data, 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; guint i, len; GstBuffer *buffer; GST_PAD_STREAM_UNLOCK (pad); GST_INFO_OBJECT (pad, "chaining each group in list as a merged buffer"); list = GST_BUFFER_LIST_CAST (data); len = gst_buffer_list_len (list); ret = GST_FLOW_OK; for (i = 0; i < len; i++) { buffer = gst_buffer_list_get (list, i); ret = gst_pad_chain_data_unchecked (pad, TRUE, gst_buffer_ref (buffer), NULL); if (ret != GST_FLOW_OK) break; } 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; } events_error: { gst_pad_data_unref (is_buffer, data); GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "events were not accepted"); GST_OBJECT_UNLOCK (pad); GST_PAD_STREAM_UNLOCK (pad); return ret; } 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: (transfer full): 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, NULL); } /** * gst_pad_chain_list: * @pad: a sink #GstPad, returns GST_FLOW_ERROR if not. * @list: (transfer full): 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, NULL); } static GstFlowReturn gst_pad_push_data (GstPad * pad, gboolean is_buffer, void *data, GstPadPushCache * cache) { GstPad *peer; GstFlowReturn ret; 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)) { cache = NULL; /* 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_CAST (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; /* take ref to peer pad before releasing the lock */ gst_object_ref (peer); GST_OBJECT_UNLOCK (pad); ret = gst_pad_chain_data_unchecked (peer, is_buffer, data, cache); gst_object_unref (peer); return ret; push_groups: { GstBufferList *list; guint i, len; GstBuffer *buffer; GST_INFO_OBJECT (pad, "pushing each group in list as a merged buffer"); list = GST_BUFFER_LIST_CAST (data); len = gst_buffer_list_len (list); for (i = 0; i < len; i++) { buffer = gst_buffer_list_get (list, i); ret = gst_pad_push_data (pad, TRUE, gst_buffer_ref (buffer), NULL); if (ret != GST_FLOW_OK) break; } 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; } } static inline GstPadPushCache * pad_take_cache (GstPad * pad, gpointer * cache_ptr) { GstPadPushCache *cache; /* try to get the cached data */ do { cache = g_atomic_pointer_get (cache_ptr); /* now try to replace the pointer with NULL to mark that we are busy * with it */ } while (!g_atomic_pointer_compare_and_exchange (cache_ptr, cache, NULL)); /* we could have a leftover invalid entry */ if (G_UNLIKELY (cache == PAD_CACHE_INVALID)) cache = NULL; return cache; } static inline void pad_free_cache (GstPadPushCache * cache) { gst_object_unref (cache->peer); g_slice_free (GstPadPushCache, cache); } static inline void pad_put_cache (GstPad * pad, GstPadPushCache * cache, gpointer * cache_ptr) { /* put it back */ if (!g_atomic_pointer_compare_and_exchange (cache_ptr, NULL, cache)) { /* something changed, clean up our cache */ pad_free_cache (cache); } } /* must be called with the pad lock */ void _priv_gst_pad_invalidate_cache (GstPad * pad) { GstPadPushCache *cache; gpointer *cache_ptr; GST_LOG_OBJECT (pad, "Invalidating pad cache"); /* we hold the pad lock here so we can get the peer and it stays * alive during this call */ if (GST_PAD_IS_SINK (pad)) { if (!(pad = GST_PAD_PEER (pad))) return; } cache_ptr = (gpointer *) & pad->priv->cache_ptr; /* try to get the cached data */ do { cache = g_atomic_pointer_get (cache_ptr); /* now try to replace the pointer with INVALID. If nothing is busy with this * caps, we get the cache and clean it up. If something is busy, we replace * with INVALID so that when the function finishes and tries to put the * cache back, it'll fail and cleanup */ } while (!g_atomic_pointer_compare_and_exchange (cache_ptr, cache, PAD_CACHE_INVALID)); if (G_LIKELY (cache && cache != PAD_CACHE_INVALID)) pad_free_cache (cache); } /** * gst_pad_push: * @pad: a source #GstPad, returns #GST_FLOW_ERROR if not. * @buffer: (transfer full): 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) { GstPadPushCache *cache; GstFlowReturn ret; gpointer *cache_ptr; GstPad *peer; 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); cache_ptr = (gpointer *) & pad->priv->cache_ptr; cache = pad_take_cache (pad, cache_ptr); if (G_UNLIKELY (cache == NULL)) goto slow_path; peer = cache->peer; GST_PAD_STREAM_LOCK (peer); if (G_UNLIKELY (g_atomic_pointer_get (cache_ptr) == PAD_CACHE_INVALID)) goto invalid; GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "calling chainfunction &%s with buffer %p", GST_DEBUG_FUNCPTR_NAME (GST_PAD_CHAINFUNC (peer)), buffer); ret = GST_PAD_CHAINFUNC (peer) (peer, buffer); GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "called chainfunction &%s with buffer %p, returned %s", GST_DEBUG_FUNCPTR_NAME (GST_PAD_CHAINFUNC (peer)), buffer, gst_flow_get_name (ret)); GST_PAD_STREAM_UNLOCK (peer); pad_put_cache (pad, cache, cache_ptr); return ret; /* slow path */ slow_path: { GstPadPushCache scache = { NULL, }; GST_LOG_OBJECT (pad, "Taking slow path"); ret = gst_pad_push_data (pad, TRUE, buffer, &scache); if (scache.peer) { GstPadPushCache *ncache; GST_LOG_OBJECT (pad, "Caching push data"); /* make cache structure */ ncache = g_slice_new (GstPadPushCache); *ncache = scache; pad_put_cache (pad, ncache, cache_ptr); } return ret; } invalid: { GST_PAD_STREAM_UNLOCK (peer); pad_free_cache (cache); goto slow_path; } } /** * gst_pad_push_list: * @pad: a source #GstPad, returns #GST_FLOW_ERROR if not. * @list: (transfer full): 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) { GstPadPushCache *cache; GstFlowReturn ret; gpointer *cache_ptr; GstPad *peer; 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); cache_ptr = (gpointer *) & pad->priv->cache_ptr; cache = pad_take_cache (pad, cache_ptr); if (G_UNLIKELY (cache == NULL)) goto slow_path; peer = cache->peer; GST_PAD_STREAM_LOCK (peer); if (G_UNLIKELY (g_atomic_pointer_get (cache_ptr) == PAD_CACHE_INVALID)) goto invalid; ret = GST_PAD_CHAINLISTFUNC (peer) (peer, list); GST_PAD_STREAM_UNLOCK (peer); pad_put_cache (pad, cache, cache_ptr); return ret; /* slow path */ slow_path: { GstPadPushCache scache = { NULL, }; GST_LOG_OBJECT (pad, "Taking slow path"); ret = gst_pad_push_data (pad, FALSE, list, &scache); if (scache.peer) { GstPadPushCache *ncache; GST_LOG_OBJECT (pad, "Caching push data"); /* make cache structure */ ncache = g_slice_new (GstPadPushCache); *ncache = scache; pad_put_cache (pad, ncache, cache_ptr); } return ret; } invalid: { GST_PAD_STREAM_UNLOCK (peer); pad_free_cache (cache); goto slow_path; } } /** * 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; 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_CAST (*buffer))) goto dropping; } GST_PAD_STREAM_UNLOCK (pad); if (G_UNLIKELY (ret != GST_FLOW_OK)) goto get_range_failed; 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; } } /** * 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: (out callee-allocates): 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: (out callee-allocates): 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; gboolean needs_events; 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_CAST (*buffer))) goto dropping; } GST_OBJECT_LOCK (pad); needs_events = GST_PAD_NEEDS_EVENTS (pad); if (G_UNLIKELY (needs_events)) { GST_OBJECT_FLAG_UNSET (pad, GST_PAD_NEED_EVENTS); GST_DEBUG_OBJECT (pad, "we need to update the events"); ret = gst_pad_update_events (pad); if (G_UNLIKELY (ret != GST_FLOW_OK)) goto events_error; } GST_OBJECT_UNLOCK (pad); 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; } events_error: { GST_OBJECT_UNLOCK (pad); gst_buffer_unref (*buffer); *buffer = NULL; GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad, "pullrange returned events that were not accepted"); return ret; } } /** * gst_pad_push_event: * @pad: a #GstPad to push the event to. * @event: (transfer full): 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; gint64 offset; 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: _priv_gst_pad_invalidate_cache (pad); 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; case GST_EVENT_RECONFIGURE: if (GST_PAD_IS_SINK (pad)) GST_OBJECT_FLAG_SET (pad, GST_PAD_NEED_RECONFIGURE); 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_CAST (event))) goto dropping; GST_OBJECT_LOCK (pad); } /* store the event on the pad, but only on srcpads */ if (GST_PAD_IS_SRC (pad) && GST_EVENT_IS_STICKY (event)) { guint idx; idx = GST_EVENT_STICKY_IDX (event); GST_LOG_OBJECT (pad, "storing sticky event %s at index %u", GST_EVENT_TYPE_NAME (event), idx); /* srcpad sticky events always become active immediately */ gst_event_replace (&pad->priv->events[idx].event, event); } if ((peerpad = GST_PAD_PEER (pad))) gst_object_ref (peerpad); offset = pad->offset; GST_OBJECT_UNLOCK (pad); /* backwards compatibility mode for caps */ switch (GST_EVENT_TYPE (event)) { case GST_EVENT_CAPS: { GstCaps *caps; gst_event_parse_caps (event, &caps); /* FIXME, this is awkward because we don't check flushing here which means * that we can call the setcaps functions on flushing pads, this is not * quite what we want, otoh, this code should just go away and elements * that set caps on their sinkpad should just setup stuff themselves. */ gst_pad_call_setcaps (pad, caps); break; } case GST_EVENT_SEGMENT: /* check if we need to adjust the segment */ if (offset != 0 && peerpad != NULL) { GstSegment segment; /* copy segment values */ gst_event_copy_segment (event, &segment); gst_event_unref (event); /* adjust and make a new event with the offset applied */ segment.base += offset; event = gst_event_new_segment (&segment); } break; default: break; } /* now check the 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); 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); 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: (transfer full): 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; gboolean serialized, need_unlock = FALSE, needs_events, sticky; 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); sticky = GST_EVENT_IS_STICKY (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 and sticky */ serialized = sticky = FALSE; } else goto unknown_direction; /* 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); } /* get the flag first, we clear it when we have a FLUSH or a non-serialized * event. */ needs_events = GST_PAD_NEEDS_EVENTS (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; _priv_gst_pad_invalidate_cache (pad); GST_PAD_SET_FLUSHING (pad); GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "set flush flag"); needs_events = FALSE; 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); needs_events = FALSE; break; case GST_EVENT_RECONFIGURE: if (GST_PAD_IS_SRC (pad)) GST_OBJECT_FLAG_SET (pad, GST_PAD_NEED_RECONFIGURE); default: GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "have event type %s", GST_EVENT_TYPE_NAME (event)); 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); } else { /* don't forward events on non-serialized events */ needs_events = FALSE; } /* store the event on the pad, but only on srcpads. We need to store the * event before checking the flushing flag. */ if (sticky) { guint idx; PadEvent *ev; switch (GST_EVENT_TYPE (event)) { case GST_EVENT_SEGMENT: if (pad->offset != 0) { GstSegment segment; /* copy segment values */ gst_event_copy_segment (event, &segment); gst_event_unref (event); /* adjust and make a new event with the offset applied */ segment.base += pad->offset; event = gst_event_new_segment (&segment); } break; default: break; } idx = GST_EVENT_STICKY_IDX (event); ev = &pad->priv->events[idx]; GST_LOG_OBJECT (pad, "storing sticky event %s at index %u", GST_EVENT_TYPE_NAME (event), idx); if (ev->event != event) { gst_event_replace (&ev->pending, event); /* set the flag so that we update the events next time. We would * usually update below but we might be flushing too. */ GST_OBJECT_FLAG_SET (pad, GST_PAD_NEED_EVENTS); needs_events = TRUE; } } /* now check the flushing flag */ if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad))) goto flushing; break; } if (G_UNLIKELY (needs_events)) { GstFlowReturn ret; GST_OBJECT_FLAG_UNSET (pad, GST_PAD_NEED_EVENTS); GST_DEBUG_OBJECT (pad, "need to update all events"); ret = gst_pad_update_events (pad); if (ret != GST_FLOW_OK) goto update_failed; GST_OBJECT_UNLOCK (pad); gst_event_unref (event); result = TRUE; } else { GstPadEventFunction eventfunc; if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL)) goto no_function; GST_OBJECT_UNLOCK (pad); result = do_event_function (pad, event, eventfunc); } 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; } update_failed: { GST_OBJECT_UNLOCK (pad); if (need_unlock) GST_PAD_STREAM_UNLOCK (pad); GST_CAT_INFO_OBJECT (GST_CAT_EVENT, pad, "Update events failed"); 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: (transfer none): a #gpointer to the private data. */ gpointer gst_pad_get_element_private (GstPad * pad) { return pad->element_private; } /** * gst_pad_get_sticky_event: * @pad: the #GstPad to get the event from. * @event_type: the #GstEventType that should be retrieved. * * Returns a new reference of the sticky event of type @event_type * from the event. * * Returns: (transfer full): a #GstEvent of type @event_type. Unref after usage. */ GstEvent * gst_pad_get_sticky_event (GstPad * pad, GstEventType event_type) { GstEvent *event = NULL; guint idx; g_return_val_if_fail (GST_IS_PAD (pad), NULL); g_return_val_if_fail ((event_type & GST_EVENT_TYPE_STICKY) != 0, NULL); idx = GST_EVENT_STICKY_IDX_TYPE (event_type); GST_OBJECT_LOCK (pad); if ((event = pad->priv->events[idx].event)) { gst_event_ref (event); } GST_OBJECT_UNLOCK (pad); return event; } 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; } }