diff options
Diffstat (limited to 'include/gst/gstelement.h')
| -rw-r--r-- | include/gst/gstelement.h | 1209 |
1 files changed, 1209 insertions, 0 deletions
diff --git a/include/gst/gstelement.h b/include/gst/gstelement.h new file mode 100644 index 0000000000..e690bf0e3f --- /dev/null +++ b/include/gst/gstelement.h @@ -0,0 +1,1209 @@ +/* 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__ + +#include <glib.h> + +G_BEGIN_DECLS + +/** + * _GST_ELEMENT_REGISTER_DEFINE_BEGIN: (attributes doc.skip=true) + */ +#define _GST_ELEMENT_REGISTER_DEFINE_BEGIN(element) \ +G_BEGIN_DECLS \ +gboolean G_PASTE (gst_element_register_, element) (GstPlugin * plugin) \ +{ \ + { + +/** + * _GST_ELEMENT_REGISTER_DEFINE_END: (attributes doc.skip=true) + */ +#define _GST_ELEMENT_REGISTER_DEFINE_END(element_name, rank, type) \ + } \ + return gst_element_register (plugin, element_name, rank, type); \ +} \ +G_END_DECLS + +/** + * GST_ELEMENT_REGISTER_DEFINE_CUSTOM: + * @element: The element name in lower case, with words separated by '_'. + * Used to generate `gst_element_register_*(GstPlugin* plugin)`. + * @register_func: pointer to a method with the format: `gboolean register_func (GstPlugin* plugin);` + * + * A convenience macro to define the entry point of an + * element `gst_element_register_*(GstPlugin* plugin)` which uses + * register_func as the main registration method for the element. + * As an example, you may define the element named "streamer-filter" + * with the namespace `my` as following using `element_register_custom`: + * + * ``` + * GST_ELEMENT_REGISTER_DEFINE_CUSTOM (my_element, element_register_custom) + * ``` + * + * Since: 1.20 + */ +#define GST_ELEMENT_REGISTER_DEFINE_CUSTOM(element, register_func) \ +G_BEGIN_DECLS \ +gboolean G_PASTE (gst_element_register_, element) (GstPlugin * plugin) \ +{ \ + return register_func (plugin); \ +} \ +G_END_DECLS + +/** + * GST_ELEMENT_REGISTER_DEFINE: + * @e: The element name in lower case, with words separated by '_'. + * Used to generate `gst_element_register_*(GstPlugin* plugin)`. + * @e_n: The public name of the element + * @r: The #GstRank of the element (higher rank means more importance when autoplugging, see #GstRank) + * @t: The #GType of the element. + * + * A convenience macro to define the entry point of an + * element `gst_element_register_*(GstPlugin* plugin)`. + * As an example, you may define the element named "streamer-filter" + * with the namespace `my` as following: + * + * ``` + * GST_ELEMENT_REGISTER_REGISTER_DEFINE (stream_filter, "stream-filter", GST_RANK_PRIMARY, MY_TYPE_STREAM_FILTER) + * ``` + * + * Since: 1.20 + */ +#define GST_ELEMENT_REGISTER_DEFINE(e, e_n, r, t) _GST_ELEMENT_REGISTER_DEFINE_BEGIN(e) _GST_ELEMENT_REGISTER_DEFINE_END(e_n, r, t) + +/** + * GST_ELEMENT_REGISTER_DEFINE_WITH_CODE: + * @e: The element name in lower case, with words separated by '_'. + * Used to generate `gst_element_register_*(GstPlugin* plugin)`. + * @e_n: The public name of the element + * @r: The #GstRank of the element (higher rank means more importance when autoplugging, see #GstRank) + * @t: The #GType of the element. + * @_c_: Custom code that gets inserted in the gst_element_register_*() function. + * + * A convenience macro to define the entry point of an + * element `gst_element_register_*(GstPlugin* plugin)` executing code + * before gst_element_register in `gst_element_register_*(GstPlugin* plugin)`. + + * As an example, you may define the element named "stream-filter" + * with the namespace `my` as following: + * + * ``` + * #define _pre_register_init \ + * my_stream_filter_pre_register (plugin); + * GST_ELEMENT_REGISTER_DEFINE_WITH_CODE (stream_filter, "stream-filter", GST_RANK_PRIMARY, MY_TYPE_STREAM_FILTER, _pre_register_init) + * ``` + * + * Since: 1.20 + */ +#define GST_ELEMENT_REGISTER_DEFINE_WITH_CODE(e, e_n, r, t, _c_) _GST_ELEMENT_REGISTER_DEFINE_BEGIN(e) {_c_;} _GST_ELEMENT_REGISTER_DEFINE_END(e_n, r, t) + +/** + * GST_ELEMENT_REGISTER_DECLARE: + * @element: The element name in lower case, with words separated by '_'. + * + * This macro can be used to declare a new element. + * It has to be used in combination with #GST_ELEMENT_REGISTER_DEFINE macros + * and must be placed outside any block to declare the element registration + * function. + * As an example, you may declare the element named "stream-filter" + * with the namespace `my` as following: + * + * ``` + * GST_ELEMENT_REGISTER_DECLARE (stream_filter) + * ``` + * + * Since: 1.20 + */ +#define GST_ELEMENT_REGISTER_DECLARE(element) \ +G_BEGIN_DECLS \ +gboolean G_PASTE(gst_element_register_, element) (GstPlugin * plugin); \ +G_END_DECLS + +/** + * GST_ELEMENT_REGISTER: + * @element: The element name in lower case, with words separated by '_'. + * @plugin: The #GstPlugin where to register the element. + * + * This macro can be used to register an element into a #GstPlugin. + * This method will be usually called in the plugin init function + * but can also be called with a NULL plugin, + * for example with a static registration of the element. + * It has to be used in combination with #GST_ELEMENT_REGISTER_DECLARE. + * + * ``` + * GstPlugin* plugin; + * + * ... + * + * GST_ELEMENT_REGISTER (stream_filter, plugin); + * ``` + * + * Since: 1.20 + */ +#define GST_ELEMENT_REGISTER(element, plugin) G_PASTE(gst_element_register_, element) (plugin) + +/* gstelement.h and gstelementfactory.h include each other */ +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 <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> +#include <gst/gstcontext.h> + +/* 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, ...) G_GNUC_NULL_TERMINATED; + +#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 [GstGError](gsterror)) + * @code: error code defined for that domain (see [GstGError](gsterror)) + * @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 [GstGError](gsterror)) + * @code: error code defined for that domain (see [GstGError](gsterror)) + * @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 [GstGError](gsterror)) + * @code: error code defined for that domain (see [GstGError](gsterror)) + * @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 [GstGError](gsterror)) + * @code: error code defined for that domain (see [GstGError](gsterror)) + * @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 [GstGError](gsterror)) + * @code: error code defined for that domain (see [GstGError](gsterror)) + * @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 [GstGError](gsterror)) + * @code: error code defined for that domain (see [GstGError](gsterror)) + * @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); + +GST_API +GstClockTime gst_element_get_current_running_time (GstElement *element); + +GST_API +GstClockTime gst_element_get_current_clock_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 G_DEPRECATED_FOR(gst_element_request_pad_simple) +GstPad* gst_element_get_request_pad (GstElement *element, const gchar *name); + +GST_API +GstPad* gst_element_request_pad_simple (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); + + +/** + * GstElementCallAsyncFunc: + * @element: The #GstElement this function has been called against + * @user_data: Data passed in the function where that callback has been passed + * + * Callback prototype used in #gst_element_call_async + */ +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); + +G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstElement, gst_object_unref) + +G_END_DECLS + +#endif /* __GST_ELEMENT_H__ */ |