/* GStreamer * Copyright (C) 1999,2000 Erik Walthinsen * 2000,2004 Wim Taymans * * gstelement.h: Header for GstElement * * 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. */ #ifndef __GST_ELEMENT_H__ #define __GST_ELEMENT_H__ /* gstelement.h and gstelementfactory.h include eachother */ typedef struct _GstElement GstElement; typedef struct _GstElementClass GstElementClass; /* gstmessage.h needs State */ /** * GstState: * @GST_STATE_VOID_PENDING : no pending state. * @GST_STATE_NULL : the NULL state or initial state of an element * @GST_STATE_READY : the element is ready to go to PAUSED * @GST_STATE_PAUSED : the element is PAUSED * @GST_STATE_PLAYING : the element is PLAYING * * The posible states an element can be in. */ typedef enum { GST_STATE_VOID_PENDING = 0, GST_STATE_NULL = 1, GST_STATE_READY = 2, GST_STATE_PAUSED = 3, GST_STATE_PLAYING = 4 } GstState; #include #include #include #include #include #include #include #include #include #include #include #include #include G_BEGIN_DECLS #define GST_TYPE_ELEMENT (gst_element_get_type ()) #define GST_IS_ELEMENT(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_ELEMENT)) #define GST_IS_ELEMENT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_ELEMENT)) #define GST_ELEMENT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_ELEMENT, GstElementClass)) #define GST_ELEMENT(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_ELEMENT, GstElement)) #define GST_ELEMENT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_ELEMENT, GstElementClass)) #define GST_ELEMENT_CAST(obj) ((GstElement*)(obj)) /** * GstStateChangeReturn: * @GST_STATE_CHANGE_FAILURE : the state change failed * @GST_STATE_CHANGE_SUCCESS : the state change succeeded * @GST_STATE_CHANGE_ASYNC : the state change will happen asynchronously * @GST_STATE_CHANGE_NO_PREROLL: the state change cannot be prerolled * * the possible return values from a state change function. */ typedef enum { GST_STATE_CHANGE_FAILURE = 0, GST_STATE_CHANGE_SUCCESS = 1, GST_STATE_CHANGE_ASYNC = 2, GST_STATE_CHANGE_NO_PREROLL = 3 } GstStateChangeReturn; /* NOTE: this probably should be done with an #ifdef to decide * whether to safe-cast or to just do the non-checking cast. */ /** * GST_STATE: * @elem: a #GstElement to return state for. * * This macro returns the current #GstState of the element. */ #define GST_STATE(elem) (GST_ELEMENT_CAST(elem)->current_state) /** * GST_STATE_NEXT: * @elem: a #GstElement to return the next state for. * * This macro returns the next #GstState of the element. */ #define GST_STATE_NEXT(elem) (GST_ELEMENT_CAST(elem)->next_state) /** * GST_STATE_PENDING: * @elem: a #GstElement to return the pending state for. * * This macro returns the currently pending #GstState of the element. */ #define GST_STATE_PENDING(elem) (GST_ELEMENT_CAST(elem)->pending_state) /** * GST_STATE_RETURN: * @elem: a #GstElement to return the last state result for. * * This macro returns the last #GstStateChangeReturn value. */ #define GST_STATE_RETURN(elem) (GST_ELEMENT_CAST(elem)->last_return) #define __GST_SIGN(val) ((val) < 0 ? -1 : ((val) > 0 ? 1 : 0)) /** * GST_STATE_GET_NEXT: * @cur: A starting #GstState * @pending: A target #GstState * * Given a current state @cur and a target state @pending, calculate the next (intermediate) * #GstState. */ #define GST_STATE_GET_NEXT(cur,pending) ((cur) + __GST_SIGN ((gint)(pending) - (gint)(cur))) /** * GST_STATE_TRANSITION: * @cur: A current state * @next: A next state * * Given a current state @cur and a next state @next, calculate the associated * #GstStateChange transition. */ #define GST_STATE_TRANSITION(cur,next) (((cur)<<3)|(next)) /** * GST_STATE_TRANSITION_CURRENT: * @trans: A #GstStateChange * * Given a state transition @trans, extract the current #GstState. */ #define GST_STATE_TRANSITION_CURRENT(trans) ((trans)>>3) /** * GST_STATE_TRANSITION_NEXT: * @trans: A #GstStateChange * * Given a state transition @trans, extract the next #GstState. */ #define GST_STATE_TRANSITION_NEXT(trans) ((trans)&0x7) /** * GstStateChange: * @GST_STATE_CHANGE_NULL_TO_READY : state change from NULL to READY * @GST_STATE_CHANGE_READY_TO_PAUSED : state change from READY to PAUSED * @GST_STATE_CHANGE_PAUSED_TO_PLAYING: state change from PAUSED to PLAYING * @GST_STATE_CHANGE_PLAYING_TO_PAUSED: state change from PLAYING to PAUSED * @GST_STATE_CHANGE_PAUSED_TO_READY : state change from PAUSED to READY * @GST_STATE_CHANGE_READY_TO_NULL : state change from READY to NULL * * The different (interesting) state changes that are passed to the * state change functions of elements. */ typedef enum /*< flags=0 >*/ { GST_STATE_CHANGE_NULL_TO_READY = (GST_STATE_NULL<<3) | GST_STATE_READY, GST_STATE_CHANGE_READY_TO_PAUSED = (GST_STATE_READY<<3) | GST_STATE_PAUSED, GST_STATE_CHANGE_PAUSED_TO_PLAYING = (GST_STATE_PAUSED<<3) | GST_STATE_PLAYING, GST_STATE_CHANGE_PLAYING_TO_PAUSED = (GST_STATE_PLAYING<<3) | GST_STATE_PAUSED, GST_STATE_CHANGE_PAUSED_TO_READY = (GST_STATE_PAUSED<<3) | GST_STATE_READY, GST_STATE_CHANGE_READY_TO_NULL = (GST_STATE_READY<<3) | GST_STATE_NULL } GstStateChange; /** * GstElementFlags: * @GST_ELEMENT_LOCKED_STATE: ignore state changes from parent * @GST_ELEMENT_IS_SINK: the element is a sink * @GST_ELEMENT_UNPARENTING: Child is being removed from the parent bin. * gst_bin_remove() on a child already being removed immediately returns FALSE * @GST_ELEMENT_FLAG_LAST: offset to define more flags * * The standard flags that an element may have. */ typedef enum { GST_ELEMENT_LOCKED_STATE = (GST_OBJECT_FLAG_LAST << 0), GST_ELEMENT_IS_SINK = (GST_OBJECT_FLAG_LAST << 1), GST_ELEMENT_UNPARENTING = (GST_OBJECT_FLAG_LAST << 2), /* padding */ GST_ELEMENT_FLAG_LAST = (GST_OBJECT_FLAG_LAST << 16) } GstElementFlags; /** * GST_ELEMENT_IS_LOCKED_STATE: * @elem: A #GstElement to query * * Check if the element is in the locked state and therefore will ignore state * changes from its parent object. */ #define GST_ELEMENT_IS_LOCKED_STATE(elem) (GST_OBJECT_FLAG_IS_SET(elem,GST_ELEMENT_LOCKED_STATE)) /** * GST_ELEMENT_NAME: * @elem: A #GstElement to query * * Gets the name of this element. Use only in core as this is not * ABI-compatible. Others use gst_element_get_name() */ #define GST_ELEMENT_NAME(elem) (GST_OBJECT_NAME(elem)) /** * GST_ELEMENT_PARENT: * @elem: A #GstElement to query * * Get the parent object of this element. */ #define GST_ELEMENT_PARENT(elem) (GST_ELEMENT_CAST(GST_OBJECT_PARENT(elem))) /** * GST_ELEMENT_BUS: * @elem: A #GstElement to query * * Get the message bus of this element. */ #define GST_ELEMENT_BUS(elem) (GST_ELEMENT_CAST(elem)->bus) /** * GST_ELEMENT_CLOCK: * @elem: A #GstElement to query * * Get the clock of this element */ #define GST_ELEMENT_CLOCK(elem) (GST_ELEMENT_CAST(elem)->clock) /** * GST_ELEMENT_PADS: * @elem: A #GstElement to query * * Get the pads of this elements. */ #define GST_ELEMENT_PADS(elem) (GST_ELEMENT_CAST(elem)->pads) /** * GST_ELEMENT_ERROR: * @el: the element that throws the error * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #GstGError) * @code: error code defined for that domain (see #GstGError) * @text: the message to display (format string and args enclosed in parentheses) * @debug: debugging information for the message (format string and args enclosed in parentheses) * * Utility function that elements can use in case they encountered a fatal * data processing error. The pipeline will throw an error signal and the * application will be requested to stop further media processing. */ #define GST_ELEMENT_ERROR(el, domain, code, text, debug) \ G_STMT_START { \ gchar *__txt = _gst_element_error_printf text; \ gchar *__dbg = _gst_element_error_printf debug; \ if (__txt) \ GST_WARNING_OBJECT (el, "error: %s", __txt); \ if (__dbg) \ GST_WARNING_OBJECT (el, "error: %s", __dbg); \ gst_element_message_full (GST_ELEMENT(el), GST_MESSAGE_ERROR, \ GST_ ## domain ## _ERROR, GST_ ## domain ## _ERROR_ ## code, \ __txt, __dbg, __FILE__, GST_FUNCTION, __LINE__); \ } G_STMT_END /** * GST_ELEMENT_WARNING: * @el: the element that throws the error * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #GstGError) * @code: error code defined for that domain (see #GstGError) * @text: the message to display (format string and args enclosed in parentheses) * @debug: debugging information for the message (format string and args enclosed in parentheses) * * Utility function that elements can use in case they encountered a non-fatal * data processing problem. The pipeline will throw a warning signal and the * application will be informed. */ #define GST_ELEMENT_WARNING(el, domain, code, text, debug) \ G_STMT_START { \ gchar *__txt = _gst_element_error_printf text; \ gchar *__dbg = _gst_element_error_printf debug; \ if (__txt) \ GST_WARNING_OBJECT (el, "warning: %s", __txt); \ if (__dbg) \ GST_WARNING_OBJECT (el, "warning: %s", __dbg); \ gst_element_message_full (GST_ELEMENT(el), GST_MESSAGE_WARNING, \ GST_ ## domain ## _ERROR, GST_ ## domain ## _ERROR_ ## code, \ __txt, __dbg, __FILE__, GST_FUNCTION, __LINE__); \ } G_STMT_END /* the state change mutexes and conds */ /** * GST_STATE_GET_LOCK: * @elem: a #GstElement * * Get a reference to the state lock of @elem. * This lock is used by the core. It is taken while getting or setting * the state, during state changes, and while finalizing. */ #define GST_STATE_GET_LOCK(elem) (GST_ELEMENT_CAST(elem)->state_lock) /** * GST_STATE_GET_COND: * @elem: a #GstElement * * Get the conditional used to signal the completion of a state change. */ #define GST_STATE_GET_COND(elem) (GST_ELEMENT_CAST(elem)->state_cond) #define GST_STATE_LOCK(elem) g_static_rec_mutex_lock(GST_STATE_GET_LOCK(elem)) #define GST_STATE_TRYLOCK(elem) g_static_rec_mutex_trylock(GST_STATE_GET_LOCK(elem)) #define GST_STATE_UNLOCK(elem) g_static_rec_mutex_unlock(GST_STATE_GET_LOCK(elem)) #define GST_STATE_UNLOCK_FULL(elem) g_static_rec_mutex_unlock_full(GST_STATE_GET_LOCK(elem)) #define GST_STATE_LOCK_FULL(elem,t) g_static_rec_mutex_lock_full(GST_STATE_GET_LOCK(elem), t) #define GST_STATE_WAIT(elem) g_cond_wait (GST_STATE_GET_COND (elem), \ GST_OBJECT_GET_LOCK (elem)) #define GST_STATE_TIMED_WAIT(elem, timeval) g_cond_timed_wait (GST_STATE_GET_COND (elem), \ GST_OBJECT_GET_LOCK (elem), timeval) #define GST_STATE_SIGNAL(elem) g_cond_signal (GST_STATE_GET_COND (elem)); #define GST_STATE_BROADCAST(elem) g_cond_broadcast (GST_STATE_GET_COND (elem)); /** * GstElement: * @state_lock: Used to serialize execution of gst_element_set_state() * @state_cond: Used to signal completion of a state change * @state_cookie: Used to detect concurrent execution of gst_element_set_state() and * gst_element_get_state() * @current_state: the current state of an element * @next_state: the next state of an element, can be #GST_STATE_VOID_PENDING if the * element is in the correct state. * @pending_state: the final state the element should go to, can be #GST_STATE_VOID_PENDING * if the element is in the correct state * @last_return: the last return value of an element state change * @bus: the bus of the element. This bus is provided to the element by the parent element * or the application. A #GstPipeline has a bus of its own. * @clock: the clock of the element. This clock is usually provided by to the element by * the toplevel #GstPipeline. * @base_time: the time of the clock right before the element is set to PLAYING. Subtracting * @base_time from the current clock time in the PLAYING state will yield the stream time. * @numpads: number of pads of the element, includes both source and sink pads. * @pads: list of pads * @numsrcpads: number of source pads of the element. * @srcpads: list of source pads * @numsinkpads: number of sink pads of the element. * @sinkpads: list of sink pads * @pads_cookie: updated whenever the a pad is added or removed * * GStreamer element abstract base class. */ struct _GstElement { GstObject object; /*< public >*/ /* with LOCK */ GStaticRecMutex *state_lock; /* element state */ GCond *state_cond; guint32 state_cookie; GstState current_state; GstState next_state; GstState pending_state; GstStateChangeReturn last_return; GstBus *bus; /* allocated clock */ GstClock *clock; GstClockTimeDiff base_time; /* NULL/READY: 0 - PAUSED: current time - PLAYING: difference to clock */ /* element pads, these lists can only be iterated while holding * the LOCK or checking the cookie after each LOCK. */ guint16 numpads; GList *pads; guint16 numsrcpads; GList *srcpads; guint16 numsinkpads; GList *sinkpads; guint32 pads_cookie; /*< private >*/ gpointer _gst_reserved[GST_PADDING]; }; /** * GstElementClass: * @parent_class: the parent class structure * @details: #GstElementDetails for elements of this class * @elementfactory: the #GstElementFactory that creates these elements * @padtemplates: a #GList of #GstPadTemplate * @numpadtemplates: the number of padtemplates * @pad_templ_cookie: changed whenever the padtemplates change * @request_new_pad: called when a new pad is requested * @release_pad: called when a request pad is to be released * @get_state: get the state of the element * @set_state: set a new state on the element * @change_state: called by @set_state to perform an incremental state change * @set_bus: set a #GstBus on the element * @provide_clock: gets the #GstClock provided by the element * @set_clock: set the #GstClock on the element * @get_index: set a #GstIndex on the element * @set_index: get the #GstIndex of an element * @send_event: send a #GstEvent to the element * @get_query_types: get the supported #GstQueryType of this element * @query: perform a #GstQuery on the element * * GStreamer element class. Override the vmethods to implement the element * functionality. */ struct _GstElementClass { GstObjectClass parent_class; /*< public >*/ /* the element details */ GstElementDetails details; /* factory that the element was created from */ GstElementFactory *elementfactory; /* templates for our pads */ GList *padtemplates; gint numpadtemplates; guint32 pad_templ_cookie; /*< private >*/ /* signal callbacks */ void (*pad_added) (GstElement *element, GstPad *pad); void (*pad_removed) (GstElement *element, GstPad *pad); void (*no_more_pads) (GstElement *element); /*< public >*/ /* virtual methods for subclasses */ /* request/release pads */ GstPad* (*request_new_pad) (GstElement *element, GstPadTemplate *templ, const gchar* name); void (*release_pad) (GstElement *element, GstPad *pad); /* state changes */ GstStateChangeReturn (*get_state) (GstElement * element, GstState * state, GstState * pending, GstClockTime timeout); GstStateChangeReturn (*set_state) (GstElement *element, GstState state); GstStateChangeReturn (*change_state) (GstElement *element, GstStateChange transition); /* bus */ void (*set_bus) (GstElement * element, GstBus * bus); /* set/get clocks */ GstClock* (*provide_clock) (GstElement *element); gboolean (*set_clock) (GstElement *element, GstClock *clock); /* index */ GstIndex* (*get_index) (GstElement *element); void (*set_index) (GstElement *element, GstIndex *index); /* query functions */ gboolean (*send_event) (GstElement *element, GstEvent *event); const GstQueryType* (*get_query_types) (GstElement *element); gboolean (*query) (GstElement *element, GstQuery *query); /*< private >*/ gpointer _gst_reserved[GST_PADDING]; }; /* element class pad templates */ void gst_element_class_add_pad_template (GstElementClass *klass, GstPadTemplate *templ); GstPadTemplate* gst_element_class_get_pad_template (GstElementClass *element_class, const gchar *name); GList* gst_element_class_get_pad_template_list (GstElementClass *element_class); void gst_element_class_set_details (GstElementClass *klass, const GstElementDetails *details); /* element instance */ GType gst_element_get_type (void); /* basic name and parentage stuff from GstObject */ /** * gst_element_get_name: * @elem: a #GstElement to set the name of. * * Gets the name of the element. */ #define gst_element_get_name(elem) gst_object_get_name(GST_OBJECT_CAST(elem)) /** * gst_element_set_name: * @elem: a #GstElement to set the name of. * @name: the new name * * Sets the name of the element, getting rid of the old name if there was one. */ #define gst_element_set_name(elem,name) gst_object_set_name(GST_OBJECT_CAST(elem),name) /** * gst_element_get_parent: * @elem: a #GstElement to get the parent of. * * Gets the parent of an element. */ #define gst_element_get_parent(elem) gst_object_get_parent(GST_OBJECT_CAST(elem)) /** * gst_element_set_parent: * @elem: a #GstElement to set the parent of. * @parent: the new parent #GstObject of the element. * * Sets the parent of an element. */ #define gst_element_set_parent(elem,parent) gst_object_set_parent(GST_OBJECT_CAST(elem),parent) /* clocking */ gboolean gst_element_requires_clock (GstElement *element); gboolean gst_element_provides_clock (GstElement *element); GstClock* gst_element_provide_clock (GstElement *element); GstClock* gst_element_get_clock (GstElement *element); gboolean gst_element_set_clock (GstElement *element, GstClock *clock); void gst_element_set_base_time (GstElement *element, GstClockTime time); GstClockTime gst_element_get_base_time (GstElement *element); /* indexes */ gboolean gst_element_is_indexable (GstElement *element); void gst_element_set_index (GstElement *element, GstIndex *index); GstIndex* gst_element_get_index (GstElement *element); /* bus */ void gst_element_set_bus (GstElement * element, GstBus * bus); GstBus * gst_element_get_bus (GstElement * element); /* pad management */ gboolean gst_element_add_pad (GstElement *element, GstPad *pad); gboolean gst_element_remove_pad (GstElement *element, GstPad *pad); void gst_element_no_more_pads (GstElement *element); GstPad* gst_element_get_pad (GstElement *element, const gchar *name); GstPad* gst_element_get_static_pad (GstElement *element, const gchar *name); GstPad* gst_element_get_request_pad (GstElement *element, const gchar *name); void gst_element_release_request_pad (GstElement *element, GstPad *pad); GstIterator * gst_element_iterate_pads (GstElement * element); GstIterator * gst_element_iterate_src_pads (GstElement * element); GstIterator * gst_element_iterate_sink_pads (GstElement * element); /* event/query/format stuff */ gboolean gst_element_send_event (GstElement *element, GstEvent *event); gboolean gst_element_seek (GstElement *element, gdouble rate, GstFormat format, GstSeekFlags flags, GstSeekType cur_type, gint64 cur, GstSeekType stop_type, gint64 stop); G_CONST_RETURN GstQueryType* gst_element_get_query_types (GstElement *element); gboolean gst_element_query (GstElement *element, GstQuery *query); /* messages */ gboolean gst_element_post_message (GstElement * element, GstMessage * message); /* error handling */ gchar * _gst_element_error_printf (const gchar *format, ...); void gst_element_message_full (GstElement * element, GstMessageType type, GQuark domain, gint code, gchar * text, gchar * debug, const gchar * file, const gchar * function, gint line); /* state management */ gboolean gst_element_is_locked_state (GstElement *element); gboolean gst_element_set_locked_state (GstElement *element, gboolean locked_state); gboolean gst_element_sync_state_with_parent (GstElement *element); GstStateChangeReturn gst_element_get_state (GstElement * element, GstState * state, GstState * pending, GstClockTime timeout); GstStateChangeReturn gst_element_set_state (GstElement *element, GstState state); void gst_element_abort_state (GstElement * element); GstStateChangeReturn gst_element_continue_state (GstElement * element, GstStateChangeReturn ret); void gst_element_lost_state (GstElement * element); /* factory management */ GstElementFactory* gst_element_get_factory (GstElement *element); G_END_DECLS #endif /* __GST_ELEMENT_H__ */