/* 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., 51 Franklin St, Fifth Floor, * Boston, MA 02110-1301, USA. */ #ifndef __GST_ELEMENT_H__ #define __GST_ELEMENT_H__ #include G_BEGIN_DECLS /* 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, it is ready to accept and * process data. Sink elements however only accept one * buffer and then block. * @GST_STATE_PLAYING : the element is PLAYING, the #GstClock is running and * the data is flowing. * * The possible states an element can be in. States can be changed using * gst_element_set_state() and checked using gst_element_get_state(). */ typedef enum { GST_STATE_VOID_PENDING = 0, GST_STATE_NULL = 1, GST_STATE_READY = 2, GST_STATE_PAUSED = 3, GST_STATE_PLAYING = 4 } GstState; #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 succeeded but the element * cannot produce data in %GST_STATE_PAUSED. * This typically happens with live sources. * * The possible return values from a state change function such as * gst_element_set_state(). Only @GST_STATE_CHANGE_FAILURE is a real failure. */ typedef enum { GST_STATE_CHANGE_FAILURE = 0, GST_STATE_CHANGE_SUCCESS = 1, GST_STATE_CHANGE_ASYNC = 2, GST_STATE_CHANGE_NO_PREROLL = 3 } GstStateChangeReturn; #include #include #include #include #include #include #include #include #include #include #include #include #include /* 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_TARGET: * @elem: a #GstElement to return the target state for. * * This macro returns the target #GstState of the element. */ #define GST_STATE_TARGET(elem) (GST_ELEMENT_CAST(elem)->target_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) ((GstState)((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) ((GstStateChange)(((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) ((GstState)((trans)>>3)) /** * GST_STATE_TRANSITION_NEXT: * @trans: A #GstStateChange * * Given a state transition @trans, extract the next #GstState. */ #define GST_STATE_TRANSITION_NEXT(trans) ((GstState)((trans)&0x7)) /** * GstStateChange: * @GST_STATE_CHANGE_NULL_TO_READY : state change from NULL to READY. * * The element must check if the resources it needs are available. Device * sinks and -sources typically try to probe the device to constrain their * caps. * * The element opens the device (in case feature need to be probed). * @GST_STATE_CHANGE_READY_TO_PAUSED : state change from READY to PAUSED. * * The element pads are activated in order to receive data in PAUSED. * Streaming threads are started. * * Some elements might need to return %GST_STATE_CHANGE_ASYNC and complete * the state change when they have enough information. It is a requirement * for sinks to return %GST_STATE_CHANGE_ASYNC and complete the state change * when they receive the first buffer or %GST_EVENT_EOS (preroll). * Sinks also block the dataflow when in PAUSED. * * A pipeline resets the running_time to 0. * * Live sources return %GST_STATE_CHANGE_NO_PREROLL and don't generate data. * @GST_STATE_CHANGE_PAUSED_TO_PLAYING: state change from PAUSED to PLAYING. * * Most elements ignore this state change. * * The pipeline selects a #GstClock and distributes this to all the children * before setting them to PLAYING. This means that it is only allowed to * synchronize on the #GstClock in the PLAYING state. * * The pipeline uses the #GstClock and the running_time to calculate the * base_time. The base_time is distributed to all children when performing * the state change. * * Sink elements stop blocking on the preroll buffer or event and start * rendering the data. * * Sinks can post %GST_MESSAGE_EOS in the PLAYING state. It is not allowed * to post %GST_MESSAGE_EOS when not in the PLAYING state. * * While streaming in PAUSED or PLAYING elements can create and remove * sometimes pads. * * Live sources start generating data and return %GST_STATE_CHANGE_SUCCESS. * @GST_STATE_CHANGE_PLAYING_TO_PAUSED: state change from PLAYING to PAUSED. * * Most elements ignore this state change. * * The pipeline calculates the running_time based on the last selected * #GstClock and the base_time. It stores this information to continue * playback when going back to the PLAYING state. * * Sinks unblock any #GstClock wait calls. * * When a sink does not have a pending buffer to play, it returns * #GST_STATE_CHANGE_ASYNC from this state change and completes the state * change when it receives a new buffer or an %GST_EVENT_EOS. * * Any queued %GST_MESSAGE_EOS items are removed since they will be reposted * when going back to the PLAYING state. The EOS messages are queued in * #GstBin containers. * * Live sources stop generating data and return %GST_STATE_CHANGE_NO_PREROLL. * @GST_STATE_CHANGE_PAUSED_TO_READY : state change from PAUSED to READY. * * Sinks unblock any waits in the preroll. * * Elements unblock any waits on devices * * Chain or get_range functions return %GST_FLOW_FLUSHING. * * The element pads are deactivated so that streaming becomes impossible and * all streaming threads are stopped. * * The sink forgets all negotiated formats * * Elements remove all sometimes pads * @GST_STATE_CHANGE_READY_TO_NULL : state change from READY to NULL. * * Elements close devices * * Elements reset any internal state. * @GST_STATE_CHANGE_NULL_TO_NULL : state change from NULL to NULL. (Since 1.14) * @GST_STATE_CHANGE_READY_TO_READY : state change from READY to READY, * This might happen when going to PAUSED asynchronously failed, in that case * elements should make sure they are in a proper, coherent READY state. (Since 1.14) * @GST_STATE_CHANGE_PAUSED_TO_PAUSED : state change from PAUSED to PAUSED. * This might happen when elements were in PLAYING state and 'lost state', * they should make sure to go back to real 'PAUSED' state (prerolling for example). (Since 1.14) * @GST_STATE_CHANGE_PLAYING_TO_PLAYING : state change from PLAYING to PLAYING. (Since 1.14) * * These are the different state changes an element goes through. * %GST_STATE_NULL ⇒ %GST_STATE_PLAYING is called an upwards state change * and %GST_STATE_PLAYING ⇒ %GST_STATE_NULL a downwards state change. */ 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, GST_STATE_CHANGE_NULL_TO_NULL = (GST_STATE_NULL<<3) | GST_STATE_NULL, GST_STATE_CHANGE_READY_TO_READY = (GST_STATE_READY<<3) | GST_STATE_READY, GST_STATE_CHANGE_PAUSED_TO_PAUSED = (GST_STATE_PAUSED<<3) | GST_STATE_PAUSED, GST_STATE_CHANGE_PLAYING_TO_PLAYING = (GST_STATE_PLAYING<<3) | GST_STATE_PLAYING } GstStateChange; /** * GstElementFlags: * @GST_ELEMENT_FLAG_LOCKED_STATE: ignore state changes from parent * @GST_ELEMENT_FLAG_SINK: the element is a sink * @GST_ELEMENT_FLAG_SOURCE: the element is a source. * @GST_ELEMENT_FLAG_PROVIDE_CLOCK: the element can provide a clock * @GST_ELEMENT_FLAG_REQUIRE_CLOCK: the element requires a clock * @GST_ELEMENT_FLAG_INDEXABLE: the element can use an index * @GST_ELEMENT_FLAG_LAST: offset to define more flags * * The standard flags that an element may have. */ typedef enum { GST_ELEMENT_FLAG_LOCKED_STATE = (GST_OBJECT_FLAG_LAST << 0), GST_ELEMENT_FLAG_SINK = (GST_OBJECT_FLAG_LAST << 1), GST_ELEMENT_FLAG_SOURCE = (GST_OBJECT_FLAG_LAST << 2), GST_ELEMENT_FLAG_PROVIDE_CLOCK = (GST_OBJECT_FLAG_LAST << 3), GST_ELEMENT_FLAG_REQUIRE_CLOCK = (GST_OBJECT_FLAG_LAST << 4), GST_ELEMENT_FLAG_INDEXABLE = (GST_OBJECT_FLAG_LAST << 5), /* padding */ GST_ELEMENT_FLAG_LAST = (GST_OBJECT_FLAG_LAST << 10) } 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_FLAG_LOCKED_STATE)) /** * GST_ELEMENT_NAME: * @elem: A #GstElement to query * * Gets the name of this element. This is not thread-safe by default * (i.e. you will have to make sure the object lock is taken yourself). * If in doubt use gst_element_get_name() instead. */ #define GST_ELEMENT_NAME(elem) (GST_OBJECT_NAME(elem)) /** * GST_ELEMENT_PARENT: * @elem: A #GstElement to query * * Get the parent object of this element. This is not thread-safe by default * (i.e. you will have to make sure the object lock is taken yourself). * If in doubt use gst_object_get_parent() instead. */ #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. This is not thread-safe by default * (i.e. you will have to make sure the object lock is taken yourself). * If in doubt use gst_element_get_bus() instead. */ #define GST_ELEMENT_BUS(elem) (GST_ELEMENT_CAST(elem)->bus) /** * GST_ELEMENT_CLOCK: * @elem: A #GstElement to query * * Get the clock of this element.This is not thread-safe by default * (i.e. you will have to make sure it is safe yourself). * If in doubt use gst_element_get_clock() instead. */ #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_START_TIME: * @elem: a #GstElement to return the start time for. * * This macro returns the start_time of the @elem. The start_time is the * running_time of the pipeline when the element went to PAUSED. */ #define GST_ELEMENT_START_TIME(elem) (GST_ELEMENT_CAST(elem)->start_time) GST_API GstStructure *gst_make_element_message_details (const char *name, ...); #define GST_ELEMENT_MESSAGE_MAKE_DETAILS(args) gst_make_element_message_details args /** * GST_ELEMENT_FLOW_ERROR: * @el: the element that generates the error * @flow_return: the GstFlowReturn leading to that ERROR message * * Utility function that elements can use in case they encountered a fatal * data processing error due to wrong flow processing. * * Since: 1.10 */ #define GST_ELEMENT_FLOW_ERROR(el,flow_return) \ G_STMT_START { \ GST_ELEMENT_ERROR_WITH_DETAILS (el, STREAM, FAILED, \ ("Internal data stream error."), \ ("streaming stopped, reason %s (%d)", gst_flow_get_name (flow_return), flow_return), \ ("flow-return", G_TYPE_INT, flow_return, NULL));\ } G_STMT_END /** * GST_ELEMENT_ERROR_WITH_DETAILS: * @el: the element that generates the error * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError) * @code: error code defined for that domain (see #gstreamer-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) * @args: optional name, type, value triplets, which will be stored * in the associated GstStructure. NULL terminator required. * Must be enclosed within parentheses. * * Utility function that elements can use in case they encountered a fatal * data processing error. The pipeline will post an error message and the * application will be requested to stop further media processing. * * Since: 1.10 */ #define GST_ELEMENT_ERROR_WITH_DETAILS(el,domain,code,text,debug,args) \ 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_with_details (GST_ELEMENT(el), \ GST_MESSAGE_ERROR, GST_ ## domain ## _ERROR, \ GST_ ## domain ## _ERROR_ ## code, __txt, __dbg, __FILE__, \ GST_FUNCTION, __LINE__, GST_ELEMENT_MESSAGE_MAKE_DETAILS(args)); \ } G_STMT_END /** * GST_ELEMENT_ERROR: * @el: the element that generates the error * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError) * @code: error code defined for that domain (see #gstreamer-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 post an error message 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_WITH_DETAILS: * @el: the element that generates the warning * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError) * @code: error code defined for that domain (see #gstreamer-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) * @args: optional name, type, value triplets, which will be stored * in the associated GstStructure. NULL terminator required. * Must be enclosed within parentheses. * * Utility function that elements can use in case they encountered a non-fatal * data processing problem. The pipeline will post a warning message and the * application will be informed. * * Since: 1.10 */ #define GST_ELEMENT_WARNING_WITH_DETAILS(el, domain, code, text, debug, args)\ 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_with_details (GST_ELEMENT(el), \ GST_MESSAGE_WARNING, GST_ ## domain ## _ERROR, \ GST_ ## domain ## _ERROR_ ## code, __txt, __dbg, __FILE__, \ GST_FUNCTION, __LINE__, GST_ELEMENT_MESSAGE_MAKE_DETAILS(args)); \ } G_STMT_END /** * GST_ELEMENT_WARNING: * @el: the element that generates the warning * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError) * @code: error code defined for that domain (see #gstreamer-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 post a warning message 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 /** * GST_ELEMENT_INFO_WITH_DETAILS: * @el: the element that generates the information * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError) * @code: error code defined for that domain (see #gstreamer-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) * @args: optional name, type, value triplets, which will be stored * in the associated GstStructure. NULL terminator required. * Must be enclosed within parentheses. * * Utility function that elements can use in case they want to inform * the application of something noteworthy that is not an error. * The pipeline will post a info message and the * application will be informed. * Optional name, type, value triplets may be supplied, and will be stored * in the associated GstStructure. NULL terminator required. * * Since: 1.10 */ #define GST_ELEMENT_INFO_WITH_DETAILS(el, domain, code, text, debug, args) \ G_STMT_START { \ gchar *__txt = _gst_element_error_printf text; \ gchar *__dbg = _gst_element_error_printf debug; \ if (__txt) \ GST_INFO_OBJECT (el, "info: %s", __txt); \ if (__dbg) \ GST_INFO_OBJECT (el, "info: %s", __dbg); \ gst_element_message_full_with_details (GST_ELEMENT(el), \ GST_MESSAGE_INFO, GST_ ## domain ## _ERROR, \ GST_ ## domain ## _ERROR_ ## code, __txt, __dbg, __FILE__, \ GST_FUNCTION, __LINE__, GST_ELEMENT_MESSAGE_MAKE_DETAILS(args)); \ } G_STMT_END /** * GST_ELEMENT_INFO: * @el: the element that generates the information * @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError) * @code: error code defined for that domain (see #gstreamer-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 want to inform * the application of something noteworthy that is not an error. * The pipeline will post a info message and the * application will be informed. */ #define GST_ELEMENT_INFO(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_INFO_OBJECT (el, "info: %s", __txt); \ if (__dbg) \ GST_INFO_OBJECT (el, "info: %s", __dbg); \ gst_element_message_full (GST_ELEMENT(el), \ GST_MESSAGE_INFO, 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_rec_mutex_lock(GST_STATE_GET_LOCK(elem)) #define GST_STATE_TRYLOCK(elem) g_rec_mutex_trylock(GST_STATE_GET_LOCK(elem)) #define GST_STATE_UNLOCK(elem) g_rec_mutex_unlock(GST_STATE_GET_LOCK(elem)) #define GST_STATE_WAIT(elem) g_cond_wait (GST_STATE_GET_COND (elem), \ GST_OBJECT_GET_LOCK (elem)) #define GST_STATE_WAIT_UNTIL(elem, end_time) g_cond_wait_until (GST_STATE_GET_COND (elem), \ GST_OBJECT_GET_LOCK (elem), end_time) #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() * @target_state: the target state of an element as set by the application * @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 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 running_time against the clock. * @start_time: the running_time of the last PAUSED state * @numpads: number of pads of the element, includes both source and sink pads. * @pads: (element-type Gst.Pad): list of pads * @numsrcpads: number of source pads of the element. * @srcpads: (element-type Gst.Pad): list of source pads * @numsinkpads: number of sink pads of the element. * @sinkpads: (element-type Gst.Pad): list of sink pads * @pads_cookie: updated whenever the a pad is added or removed * @contexts: (element-type Gst.Context): list of contexts * * GStreamer element abstract base class. */ struct _GstElement { GstObject object; /*< public >*/ /* with LOCK */ GRecMutex state_lock; /* element state */ GCond state_cond; guint32 state_cookie; GstState target_state; 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 */ GstClockTime start_time; /* 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; /* with object LOCK */ GList *contexts; /*< private >*/ gpointer _gst_reserved[GST_PADDING-1]; }; /** * GstElementClass: * @parent_class: the parent class structure * @metadata: metadata 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 * @send_event: send a #GstEvent to the element * @query: perform a #GstQuery on the element * @state_changed: called immediately after a new state was set. * @post_message: called when a message is posted on the element. Chain up to * the parent class' handler to have it posted on the bus. * @set_context: set a #GstContext on the element * * GStreamer element class. Override the vmethods to implement the element * functionality. */ struct _GstElementClass { GstObjectClass parent_class; /*< public >*/ /* the element metadata */ gpointer metadata; /* 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 */ /* FIXME 2.0 harmonize naming with gst_element_request_pad */ GstPad* (*request_new_pad) (GstElement *element, GstPadTemplate *templ, const gchar* name, const GstCaps *caps); 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); void (*state_changed) (GstElement *element, GstState oldstate, GstState newstate, GstState pending); /* bus */ void (*set_bus) (GstElement * element, GstBus * bus); /* set/get clocks */ GstClock* (*provide_clock) (GstElement *element); gboolean (*set_clock) (GstElement *element, GstClock *clock); /* query functions */ gboolean (*send_event) (GstElement *element, GstEvent *event); gboolean (*query) (GstElement *element, GstQuery *query); gboolean (*post_message) (GstElement *element, GstMessage *message); void (*set_context) (GstElement *element, GstContext *context); /*< private >*/ gpointer _gst_reserved[GST_PADDING_LARGE-2]; }; /* element class pad templates */ GST_API void gst_element_class_add_pad_template (GstElementClass *klass, GstPadTemplate *templ); GST_API void gst_element_class_add_static_pad_template (GstElementClass *klass, GstStaticPadTemplate *static_templ); GST_API void gst_element_class_add_static_pad_template_with_gtype (GstElementClass *klass, GstStaticPadTemplate *static_templ, GType pad_type); GST_API GstPadTemplate* gst_element_class_get_pad_template (GstElementClass *element_class, const gchar *name); GST_API GList* gst_element_class_get_pad_template_list (GstElementClass *element_class); /* element class meta data */ GST_API void gst_element_class_set_metadata (GstElementClass *klass, const gchar *longname, const gchar *classification, const gchar *description, const gchar *author); GST_API void gst_element_class_set_static_metadata (GstElementClass *klass, const gchar *longname, const gchar *classification, const gchar *description, const gchar *author); GST_API void gst_element_class_add_metadata (GstElementClass * klass, const gchar * key, const gchar * value); GST_API void gst_element_class_add_static_metadata (GstElementClass * klass, const gchar * key, const gchar * value); GST_API const gchar * gst_element_class_get_metadata (GstElementClass * klass, const gchar * key); /* element instance */ GST_API GType gst_element_get_type (void); /* basic name and parentage stuff from GstObject */ /** * gst_element_get_name: * @elem: a #GstElement to get the name of @elem. * * Returns a copy of the name of @elem. * Caller should g_free() the return value after usage. * For a nameless element, this returns %NULL, which you can safely g_free() * as well. * * Returns: (transfer full) (nullable): the name of @elem. g_free() * after usage. MT safe. * */ #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. * * Get the parent of an element. * * Returns: (transfer full): 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 */ GST_API GstClock* gst_element_provide_clock (GstElement *element); GST_API GstClock* gst_element_get_clock (GstElement *element); GST_API gboolean gst_element_set_clock (GstElement *element, GstClock *clock); GST_API void gst_element_set_base_time (GstElement *element, GstClockTime time); GST_API GstClockTime gst_element_get_base_time (GstElement *element); GST_API void gst_element_set_start_time (GstElement *element, GstClockTime time); GST_API GstClockTime gst_element_get_start_time (GstElement *element); /* bus */ GST_API void gst_element_set_bus (GstElement * element, GstBus * bus); GST_API GstBus * gst_element_get_bus (GstElement * element); /* context */ GST_API void gst_element_set_context (GstElement * element, GstContext * context); GST_API GList * gst_element_get_contexts (GstElement * element); GST_API GstContext * gst_element_get_context (GstElement * element, const gchar * context_type); GST_API GstContext * gst_element_get_context_unlocked (GstElement * element, const gchar * context_type); /* pad management */ GST_API gboolean gst_element_add_pad (GstElement *element, GstPad *pad); GST_API gboolean gst_element_remove_pad (GstElement *element, GstPad *pad); GST_API void gst_element_no_more_pads (GstElement *element); GST_API GstPad* gst_element_get_static_pad (GstElement *element, const gchar *name); GST_API GstPad* gst_element_get_request_pad (GstElement *element, const gchar *name); GST_API GstPad* gst_element_request_pad (GstElement *element, GstPadTemplate *templ, const gchar * name, const GstCaps *caps); GST_API void gst_element_release_request_pad (GstElement *element, GstPad *pad); GST_API GstIterator * gst_element_iterate_pads (GstElement * element); GST_API GstIterator * gst_element_iterate_src_pads (GstElement * element); GST_API GstIterator * gst_element_iterate_sink_pads (GstElement * element); /** * GstElementForeachPadFunc: * @element: the #GstElement * @pad: a #GstPad * @user_data: user data passed to the foreach function * * Function called for each pad when using gst_element_foreach_sink_pad(), * gst_element_foreach_src_pad(), or gst_element_foreach_pad(). * * Returns: %FALSE to stop iterating pads, %TRUE to continue * * Since: 1.14 */ typedef gboolean (*GstElementForeachPadFunc) (GstElement * element, GstPad * pad, gpointer user_data); GST_API gboolean gst_element_foreach_sink_pad (GstElement * element, GstElementForeachPadFunc func, gpointer user_data); GST_API gboolean gst_element_foreach_src_pad (GstElement * element, GstElementForeachPadFunc func, gpointer user_data); GST_API gboolean gst_element_foreach_pad (GstElement * element, GstElementForeachPadFunc func, gpointer user_data); /* event/query/format stuff */ GST_API gboolean gst_element_send_event (GstElement *element, GstEvent *event); GST_API gboolean gst_element_seek (GstElement *element, gdouble rate, GstFormat format, GstSeekFlags flags, GstSeekType start_type, gint64 start, GstSeekType stop_type, gint64 stop); GST_API gboolean gst_element_query (GstElement *element, GstQuery *query); /* messages */ GST_API gboolean gst_element_post_message (GstElement * element, GstMessage * message); /* error handling */ /* gcc versions < 3.3 warn about NULL being passed as format to printf */ #if (!defined(__GNUC__) || (__GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 3)) GST_API gchar * _gst_element_error_printf (const gchar *format, ...); #else GST_API gchar * _gst_element_error_printf (const gchar *format, ...) G_GNUC_PRINTF (1, 2); #endif GST_API 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); GST_API void gst_element_message_full_with_details (GstElement * element, GstMessageType type, GQuark domain, gint code, gchar * text, gchar * debug, const gchar * file, const gchar * function, gint line, GstStructure * structure); /* state management */ GST_API gboolean gst_element_is_locked_state (GstElement *element); GST_API gboolean gst_element_set_locked_state (GstElement *element, gboolean locked_state); GST_API gboolean gst_element_sync_state_with_parent (GstElement *element); GST_API GstStateChangeReturn gst_element_get_state (GstElement * element, GstState * state, GstState * pending, GstClockTime timeout); GST_API GstStateChangeReturn gst_element_set_state (GstElement *element, GstState state); GST_API void gst_element_abort_state (GstElement * element); GST_API GstStateChangeReturn gst_element_change_state (GstElement * element, GstStateChange transition); GST_API GstStateChangeReturn gst_element_continue_state (GstElement * element, GstStateChangeReturn ret); GST_API void gst_element_lost_state (GstElement * element); typedef void (*GstElementCallAsyncFunc) (GstElement * element, gpointer user_data); GST_API void gst_element_call_async (GstElement * element, GstElementCallAsyncFunc func, gpointer user_data, GDestroyNotify destroy_notify); /* factory management */ GST_API GstElementFactory* gst_element_get_factory (GstElement *element); /* utility functions */ GST_API gulong gst_element_add_property_notify_watch (GstElement * element, const gchar * property_name, gboolean include_value); GST_API gulong gst_element_add_property_deep_notify_watch (GstElement * element, const gchar * property_name, gboolean include_value); GST_API void gst_element_remove_property_notify_watch (GstElement * element, gulong watch_id); GST_API GstPadTemplate* gst_element_get_pad_template (GstElement *element, const gchar *name); GST_API GList* gst_element_get_pad_template_list (GstElement *element); GST_API const gchar * gst_element_get_metadata (GstElement * element, const gchar * key); #ifdef G_DEFINE_AUTOPTR_CLEANUP_FUNC G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstElement, gst_object_unref) #endif G_END_DECLS #endif /* __GST_ELEMENT_H__ */