| /* GStreamer |
| * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu> |
| * 2000,2004 Wim Taymans <wim@fluendo.com> |
| * |
| * 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__ |
| |
| /* 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; |
| |
| |
| #include <gst/gstconfig.h> |
| #include <gst/gstobject.h> |
| #include <gst/gstpad.h> |
| #include <gst/gstbus.h> |
| #include <gst/gstclock.h> |
| #include <gst/gstelementfactory.h> |
| #include <gst/gstplugin.h> |
| #include <gst/gstpluginfeature.h> |
| #include <gst/gstiterator.h> |
| #include <gst/gstmessage.h> |
| #include <gst/gstquery.h> |
| #include <gst/gsttaglist.h> |
| |
| 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 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; |
| |
| /* 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. |
| * <itemizedlist> |
| * <listitem><para> |
| * 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. |
| * </para></listitem> |
| * <listitem><para> |
| * The element opens the device (in case feature need to be probed). |
| * </para></listitem> |
| * </itemizedlist> |
| * @GST_STATE_CHANGE_READY_TO_PAUSED : state change from READY to PAUSED. |
| * <itemizedlist> |
| * <listitem><para> |
| * The element pads are activated in order to receive data in PAUSED. |
| * Streaming threads are started. |
| * </para></listitem> |
| * <listitem><para> |
| * 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. |
| * </para></listitem> |
| * <listitem><para> |
| * A pipeline resets the running_time to 0. |
| * </para></listitem> |
| * <listitem><para> |
| * Live sources return %GST_STATE_CHANGE_NO_PREROLL and don't generate data. |
| * </para></listitem> |
| * </itemizedlist> |
| * @GST_STATE_CHANGE_PAUSED_TO_PLAYING: state change from PAUSED to PLAYING. |
| * <itemizedlist> |
| * <listitem><para> |
| * Most elements ignore this state change. |
| * </para></listitem> |
| * <listitem><para> |
| * 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. |
| * </para></listitem> |
| * <listitem><para> |
| * 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. |
| * </para></listitem> |
| * <listitem><para> |
| * Sink elements stop blocking on the preroll buffer or event and start |
| * rendering the data. |
| * </para></listitem> |
| * <listitem><para> |
| * 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. |
| * </para></listitem> |
| * <listitem><para> |
| * While streaming in PAUSED or PLAYING elements can create and remove |
| * sometimes pads. |
| * </para></listitem> |
| * <listitem><para> |
| * Live sources start generating data and return %GST_STATE_CHANGE_SUCCESS. |
| * </para></listitem> |
| * </itemizedlist> |
| * @GST_STATE_CHANGE_PLAYING_TO_PAUSED: state change from PLAYING to PAUSED. |
| * <itemizedlist> |
| * <listitem><para> |
| * Most elements ignore this state change. |
| * </para></listitem> |
| * <listitem><para> |
| * 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. |
| * </para></listitem> |
| * <listitem><para> |
| * Sinks unblock any #GstClock wait calls. |
| * </para></listitem> |
| * <listitem><para> |
| * 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. |
| * </para></listitem> |
| * <listitem><para> |
| * 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. |
| * </para></listitem> |
| * <listitem><para> |
| * Live sources stop generating data and return %GST_STATE_CHANGE_NO_PREROLL. |
| * </para></listitem> |
| * </itemizedlist> |
| * @GST_STATE_CHANGE_PAUSED_TO_READY : state change from PAUSED to READY. |
| * <itemizedlist> |
| * <listitem><para> |
| * Sinks unblock any waits in the preroll. |
| * </para></listitem> |
| * <listitem><para> |
| * Elements unblock any waits on devices |
| * </para></listitem> |
| * <listitem><para> |
| * Chain or get_range functions return %GST_FLOW_FLUSHING. |
| * </para></listitem> |
| * <listitem><para> |
| * The element pads are deactivated so that streaming becomes impossible and |
| * all streaming threads are stopped. |
| * </para></listitem> |
| * <listitem><para> |
| * The sink forgets all negotiated formats |
| * </para></listitem> |
| * <listitem><para> |
| * Elements remove all sometimes pads |
| * </para></listitem> |
| * </itemizedlist> |
| * @GST_STATE_CHANGE_READY_TO_NULL : state change from READY to NULL. |
| * <itemizedlist> |
| * <listitem><para> |
| * Elements close devices |
| * </para></listitem> |
| * <listitem><para> |
| * Elements reset any internal state. |
| * </para></listitem> |
| * </itemizedlist> |
| * |
| * 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 |
| } 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. 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_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_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: |
| * @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: |
| * @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 |
| * |
| * 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 */ |
| void gst_element_class_add_pad_template (GstElementClass *klass, GstPadTemplate *templ); |
| |
| void gst_element_class_add_static_pad_template (GstElementClass *klass, GstStaticPadTemplate *static_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); |
| |
| /* element class meta data */ |
| void gst_element_class_set_metadata (GstElementClass *klass, |
| const gchar *longname, |
| const gchar *classification, |
| const gchar *description, |
| const gchar *author); |
| void gst_element_class_set_static_metadata (GstElementClass *klass, |
| const gchar *longname, |
| const gchar *classification, |
| const gchar *description, |
| const gchar *author); |
| void gst_element_class_add_metadata (GstElementClass * klass, |
| const gchar * key, const gchar * value); |
| void gst_element_class_add_static_metadata (GstElementClass * klass, |
| const gchar * key, const gchar * value); |
| const gchar * gst_element_class_get_metadata (GstElementClass * klass, |
| const gchar * key); |
| |
| |
| /* element instance */ |
| 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 */ |
| 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); |
| void gst_element_set_start_time (GstElement *element, GstClockTime time); |
| GstClockTime gst_element_get_start_time (GstElement *element); |
| |
| /* bus */ |
| void gst_element_set_bus (GstElement * element, GstBus * bus); |
| GstBus * gst_element_get_bus (GstElement * element); |
| |
| /* context */ |
| void gst_element_set_context (GstElement * element, GstContext * context); |
| GList * gst_element_get_contexts (GstElement * element); |
| GstContext * gst_element_get_context (GstElement * element, const gchar * context_type); |
| GstContext * gst_element_get_context_unlocked (GstElement * element, const gchar * context_type); |
| |
| /* 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_static_pad (GstElement *element, const gchar *name); |
| GstPad* gst_element_get_request_pad (GstElement *element, const gchar *name); |
| GstPad* gst_element_request_pad (GstElement *element, GstPadTemplate *templ, |
| const gchar * name, const GstCaps *caps); |
| 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 start_type, gint64 start, |
| GstSeekType stop_type, gint64 stop); |
| gboolean gst_element_query (GstElement *element, GstQuery *query); |
| |
| /* messages */ |
| 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)) |
| gchar * _gst_element_error_printf (const gchar *format, ...); |
| #else |
| gchar * _gst_element_error_printf (const gchar *format, ...) G_GNUC_PRINTF (1, 2); |
| #endif |
| 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_change_state (GstElement * element, |
| GstStateChange transition); |
| 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); |
| |
| #ifdef G_DEFINE_AUTOPTR_CLEANUP_FUNC |
| G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstElement, gst_object_unref) |
| #endif |
| |
| G_END_DECLS |
| |
| #endif /* __GST_ELEMENT_H__ */ |
