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gstreamer/gst/gstpad.h
Evan Nemerson 6c6bb0e217 introspection: assorted introspection and documentation fixes 
These changes are to clean up syntax issues such as missing colons,
missing spaces, etc., and minor issues such as argument names in
headers not matching the implementation and/or documentation.
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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wim.taymans@chello.be>
*
* gstpad.h: Header for GstPad object
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifndef __GST_PAD_H__
#define __GST_PAD_H__
#include <gst/gstconfig.h>
typedef struct _GstPad GstPad;
typedef struct _GstPadPrivate GstPadPrivate;
typedef struct _GstPadClass GstPadClass;
typedef struct _GstPadProbeInfo GstPadProbeInfo;
/**
* GstPadDirection:
* @GST_PAD_UNKNOWN: direction is unknown.
* @GST_PAD_SRC: the pad is a source pad.
* @GST_PAD_SINK: the pad is a sink pad.
*
* The direction of a pad.
*/
typedef enum {
GST_PAD_UNKNOWN,
GST_PAD_SRC,
GST_PAD_SINK
} GstPadDirection;
/**
* GstPadMode:
* @GST_PAD_MODE_NONE: Pad will not handle dataflow
* @GST_PAD_MODE_PUSH: Pad handles dataflow in downstream push mode
* @GST_PAD_MODE_PULL: Pad handles dataflow in upstream pull mode
*
* The status of a GstPad. After activating a pad, which usually happens when the
* parent element goes from READY to PAUSED, the GstPadMode defines if the
* pad operates in push or pull mode.
*/
typedef enum {
GST_PAD_MODE_NONE,
GST_PAD_MODE_PUSH,
GST_PAD_MODE_PULL
} GstPadMode;
#include <gst/gstobject.h>
#include <gst/gstbuffer.h>
#include <gst/gstbufferlist.h>
#include <gst/gstcaps.h>
#include <gst/gstpadtemplate.h>
#include <gst/gstevent.h>
#include <gst/gstquery.h>
#include <gst/gsttask.h>
G_BEGIN_DECLS
/*
* Pad base class
*/
#define GST_TYPE_PAD (gst_pad_get_type ())
#define GST_IS_PAD(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_PAD))
#define GST_IS_PAD_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_PAD))
#define GST_PAD(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_PAD, GstPad))
#define GST_PAD_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_PAD, GstPadClass))
#define GST_PAD_CAST(obj) ((GstPad*)(obj))
/**
* GstPadLinkReturn:
* @GST_PAD_LINK_OK : link succeeded
* @GST_PAD_LINK_WRONG_HIERARCHY: pads have no common grandparent
* @GST_PAD_LINK_WAS_LINKED : pad was already linked
* @GST_PAD_LINK_WRONG_DIRECTION: pads have wrong direction
* @GST_PAD_LINK_NOFORMAT : pads do not have common format
* @GST_PAD_LINK_NOSCHED : pads cannot cooperate in scheduling
* @GST_PAD_LINK_REFUSED : refused for some reason
*
* Result values from gst_pad_link and friends.
*/
typedef enum {
GST_PAD_LINK_OK = 0,
GST_PAD_LINK_WRONG_HIERARCHY = -1,
GST_PAD_LINK_WAS_LINKED = -2,
GST_PAD_LINK_WRONG_DIRECTION = -3,
GST_PAD_LINK_NOFORMAT = -4,
GST_PAD_LINK_NOSCHED = -5,
GST_PAD_LINK_REFUSED = -6
} GstPadLinkReturn;
/**
* GST_PAD_LINK_FAILED:
* @ret: the #GstPadLinkReturn value
*
* Macro to test if the given #GstPadLinkReturn value indicates a failed
* link step.
*/
#define GST_PAD_LINK_FAILED(ret) ((ret) < GST_PAD_LINK_OK)
/**
* GST_PAD_LINK_SUCCESSFUL:
* @ret: the #GstPadLinkReturn value
*
* Macro to test if the given #GstPadLinkReturn value indicates a successful
* link step.
*/
#define GST_PAD_LINK_SUCCESSFUL(ret) ((ret) >= GST_PAD_LINK_OK)
/**
* GstFlowReturn:
* @GST_FLOW_OK: Data passing was ok.
* @GST_FLOW_NOT_LINKED: Pad is not linked.
* @GST_FLOW_FLUSHING: Pad is flushing.
* @GST_FLOW_EOS: Pad is EOS.
* @GST_FLOW_NOT_NEGOTIATED: Pad is not negotiated.
* @GST_FLOW_ERROR: Some (fatal) error occured. Element generating
* this error should post an error message with more
* details.
* @GST_FLOW_NOT_SUPPORTED: This operation is not supported.
* @GST_FLOW_CUSTOM_SUCCESS: Elements can use values starting from
* this (and higher) to define custom success
* codes. Since 0.10.7.
* @GST_FLOW_CUSTOM_SUCCESS_1: Pre-defined custom success code (define your
* custom success code to this to avoid compiler
* warnings). Since 0.10.29.
* @GST_FLOW_CUSTOM_SUCCESS_2: Pre-defined custom success code. Since 0.10.29.
* @GST_FLOW_CUSTOM_ERROR: Elements can use values starting from
* this (and lower) to define custom error codes.
* Since 0.10.7.
* @GST_FLOW_CUSTOM_ERROR_1: Pre-defined custom error code (define your
* custom error code to this to avoid compiler
* warnings). Since 0.10.29.
* @GST_FLOW_CUSTOM_ERROR_2: Pre-defined custom error code. Since 0.10.29.
*
* The result of passing data to a pad.
*
* Note that the custom return values should not be exposed outside of the
* element scope and are available since 0.10.7.
*/
/* FIXME 0.11: remove custom flow returns */
typedef enum {
/* custom success starts here */
GST_FLOW_CUSTOM_SUCCESS_2 = 102,
GST_FLOW_CUSTOM_SUCCESS_1 = 101,
GST_FLOW_CUSTOM_SUCCESS = 100,
/* core predefined */
GST_FLOW_OK = 0,
/* expected failures */
GST_FLOW_NOT_LINKED = -1,
GST_FLOW_FLUSHING = -2,
/* error cases */
GST_FLOW_EOS = -3,
GST_FLOW_NOT_NEGOTIATED = -4,
GST_FLOW_ERROR = -5,
GST_FLOW_NOT_SUPPORTED = -6,
/* custom error starts here */
GST_FLOW_CUSTOM_ERROR = -100,
GST_FLOW_CUSTOM_ERROR_1 = -101,
GST_FLOW_CUSTOM_ERROR_2 = -102
} GstFlowReturn;
const gchar* gst_flow_get_name (GstFlowReturn ret);
GQuark gst_flow_to_quark (GstFlowReturn ret);
/**
* GstPadLinkCheck:
* @GST_PAD_LINK_CHECK_NOTHING: Don't check hierarchy or caps compatibility.
* @GST_PAD_LINK_CHECK_HIERARCHY: Check the pads have same parents/grandparents.
* Could be omitted if it is already known that the two elements that own the
* pads are in the same bin.
* @GST_PAD_LINK_CHECK_TEMPLATE_CAPS: Check if the pads are compatible by using
* their template caps. This is much faster than @GST_PAD_LINK_CHECK_CAPS, but
* would be unsafe e.g. if one pad has %GST_CAPS_ANY.
* @GST_PAD_LINK_CHECK_CAPS: Check if the pads are compatible by comparing the
* caps returned by gst_pad_query_caps().
*
* The amount of checking to be done when linking pads. @GST_PAD_LINK_CHECK_CAPS
* and @GST_PAD_LINK_CHECK_TEMPLATE_CAPS are mutually exclusive. If both are
* specified, expensive but safe @GST_PAD_LINK_CHECK_CAPS are performed.
*
* <warning><para>
* Only disable some of the checks if you are 100% certain you know the link
* will not fail because of hierarchy/caps compatibility failures. If uncertain,
* use the default checks (%GST_PAD_LINK_CHECK_DEFAULT) or the regular methods
* for linking the pads.
* </para></warning>
*
* Since: 0.10.30
*/
typedef enum {
GST_PAD_LINK_CHECK_NOTHING = 0,
GST_PAD_LINK_CHECK_HIERARCHY = 1 << 0,
GST_PAD_LINK_CHECK_TEMPLATE_CAPS = 1 << 1,
GST_PAD_LINK_CHECK_CAPS = 1 << 2
} GstPadLinkCheck;
/**
* GST_PAD_LINK_CHECK_DEFAULT:
*
* The default checks done when linking pads (i.e. the ones used by
* gst_pad_link()).
*
* Since: 0.10.30
*/
#define GST_PAD_LINK_CHECK_DEFAULT ((GstPadLinkCheck) (GST_PAD_LINK_CHECK_HIERARCHY | GST_PAD_LINK_CHECK_CAPS))
/* pad states */
/**
* GstPadActivateFunction:
* @pad: a #GstPad
* @parent: the parent of @pad
*
* This function is called when the pad is activated during the element
* READY to PAUSED state change. By default this function will call the
* activate function that puts the pad in push mode but elements can
* override this function to activate the pad in pull mode if they wish.
*
* Returns: TRUE if the pad could be activated.
*/
typedef gboolean (*GstPadActivateFunction) (GstPad *pad, GstObject *parent);
/**
* GstPadActivateModeFunction:
* @pad: a #GstPad
* @parent: the parent of @pad
* @mode: the requested activation mode of @pad
* @active: activate or deactivate the pad.
*
* The prototype of the push and pull activate functions.
*
* Returns: TRUE if the pad could be activated or deactivated.
*/
typedef gboolean (*GstPadActivateModeFunction) (GstPad *pad, GstObject *parent,
GstPadMode mode, gboolean active);
/* data passing */
/**
* GstPadChainFunction:
* @pad: the sink #GstPad that performed the chain.
* @parent: the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT flag is set,
* @parent is guaranteed to be not-NULL and remain valid during the
* execution of this function.
* @buffer: the #GstBuffer that is chained, not %NULL.
*
* A function that will be called on sinkpads when chaining buffers.
* The function typically processes the data contained in the buffer and
* either consumes the data or passes it on to the internally linked pad(s).
*
* The implementer of this function receives a refcount to @buffer and should
* gst_buffer_unref() when the buffer is no longer needed.
*
* When a chain function detects an error in the data stream, it must post an
* error on the bus and return an appropriate #GstFlowReturn value.
*
* Returns: #GST_FLOW_OK for success
*/
typedef GstFlowReturn (*GstPadChainFunction) (GstPad *pad, GstObject *parent,
GstBuffer *buffer);
/**
* GstPadChainListFunction:
* @pad: the sink #GstPad that performed the chain.
* @parent: the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT flag is set,
* @parent is guaranteed to be not-NULL and remain valid during the
* execution of this function.
* @list: the #GstBufferList that is chained, not %NULL.
*
* A function that will be called on sinkpads when chaining buffer lists.
* The function typically processes the data contained in the buffer list and
* either consumes the data or passes it on to the internally linked pad(s).
*
* The implementer of this function receives a refcount to @list and
* should gst_buffer_list_unref() when the list is no longer needed.
*
* When a chainlist function detects an error in the data stream, it must
* post an error on the bus and return an appropriate #GstFlowReturn value.
*
* Returns: #GST_FLOW_OK for success
*/
typedef GstFlowReturn (*GstPadChainListFunction) (GstPad *pad, GstObject *parent,
GstBufferList *list);
/**
* GstPadGetRangeFunction:
* @pad: the src #GstPad to perform the getrange on.
* @parent: the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT flag is set,
* @parent is guaranteed to be not-NULL and remain valid during the
* execution of this function.
* @offset: the offset of the range
* @length: the length of the range
* @buffer: a memory location to hold the result buffer, cannot be NULL.
*
* This function will be called on source pads when a peer element
* request a buffer at the specified @offset and @length. If this function
* returns #GST_FLOW_OK, the result buffer will be stored in @buffer. The
* contents of @buffer is invalid for any other return value.
*
* This function is installed on a source pad with
* gst_pad_set_getrange_function() and can only be called on source pads after
* they are successfully activated with gst_pad_activate_pull().
*
* @offset and @length are always given in byte units. @offset must normally be a value
* between 0 and the length in bytes of the data available on @pad. The
* length (duration in bytes) can be retrieved with a #GST_QUERY_DURATION or with a
* #GST_QUERY_SEEKING.
*
* Any @offset larger or equal than the length will make the function return
* #GST_FLOW_EOS, which corresponds to EOS. In this case @buffer does not
* contain a valid buffer.
*
* The buffer size of @buffer will only be smaller than @length when @offset is
* near the end of the stream. In all other cases, the size of @buffer must be
* exactly the requested size.
*
* It is allowed to call this function with a 0 @length and valid @offset, in
* which case @buffer will contain a 0-sized buffer and the function returns
* #GST_FLOW_OK.
*
* When this function is called with a -1 @offset, the sequentially next buffer
* of length @length in the stream is returned.
*
* When this function is called with a -1 @length, a buffer with a default
* optimal length is returned in @buffer. The length might depend on the value
* of @offset.
*
* Returns: #GST_FLOW_OK for success and a valid buffer in @buffer. Any other
* return value leaves @buffer undefined.
*/
typedef GstFlowReturn (*GstPadGetRangeFunction) (GstPad *pad, GstObject *parent,
guint64 offset, guint length,
GstBuffer **buffer);
/**
* GstPadEventFunction:
* @pad: the #GstPad to handle the event.
* @parent: the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT flag is set,
* @parent is guaranteed to be not-NULL and remain valid during the
* execution of this function.
* @event: the #GstEvent to handle.
*
* Function signature to handle an event for the pad.
*
* Returns: TRUE if the pad could handle the event.
*/
typedef gboolean (*GstPadEventFunction) (GstPad *pad, GstObject *parent,
GstEvent *event);
/* internal links */
/**
* GstPadIterIntLinkFunction:
* @pad: The #GstPad to query.
* @parent: the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT flag is set,
* @parent is guaranteed to be not-NULL and remain valid during the
* execution of this function.
*
* The signature of the internal pad link iterator function.
*
* Returns: a new #GstIterator that will iterate over all pads that are
* linked to the given pad on the inside of the parent element.
*
* the caller must call gst_iterator_free() after usage.
*
* Since 0.10.21
*/
typedef GstIterator* (*GstPadIterIntLinkFunction) (GstPad *pad, GstObject *parent);
/* generic query function */
/**
* GstPadQueryFunction:
* @pad: the #GstPad to query.
* @parent: the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT flag is set,
* @parent is guaranteed to be not-NULL and remain valid during the
* execution of this function.
* @query: the #GstQuery object to execute
*
* The signature of the query function.
*
* Returns: TRUE if the query could be performed.
*/
typedef gboolean (*GstPadQueryFunction) (GstPad *pad, GstObject *parent,
GstQuery *query);
/* linking */
/**
* GstPadLinkFunction:
* @pad: the #GstPad that is linked.
* @peer: the peer #GstPad of the link
*
* Function signature to handle a new link on the pad.
*
* Returns: the result of the link with the specified peer.
*/
typedef GstPadLinkReturn (*GstPadLinkFunction) (GstPad *pad, GstPad *peer);
/**
* GstPadUnlinkFunction:
* @pad: the #GstPad that is linked.
*
* Function signature to handle a unlinking the pad prom its peer.
*/
typedef void (*GstPadUnlinkFunction) (GstPad *pad);
/* misc */
/**
* GstPadForwardFunction:
* @pad: the #GstPad that is forwarded.
* @user_data: the gpointer to optional user data.
*
* A forward function is called for all internally linked pads, see
* gst_pad_forward().
*
* Returns: TRUE if the dispatching procedure has to be stopped.
*/
typedef gboolean (*GstPadForwardFunction) (GstPad *pad, gpointer user_data);
/**
* GstPadProbeType:
* @GST_PAD_PROBE_TYPE_INVALID: invalid probe type
* @GST_PAD_PROBE_TYPE_IDLE: probe idle pads and block
* @GST_PAD_PROBE_TYPE_BLOCK: probe and block pads
* @GST_PAD_PROBE_TYPE_BUFFER: probe buffers
* @GST_PAD_PROBE_TYPE_BUFFER_LIST: probe buffer lists
* @GST_PAD_PROBE_TYPE_EVENT_DOWNSTREAM: probe downstream events
* @GST_PAD_PROBE_TYPE_EVENT_UPSTREAM: probe upstream events
* @GST_PAD_PROBE_TYPE_EVENT_FLUSH: probe flush events. This probe has to be
* explicitly enabled and is not included in the
* @@GST_PAD_PROBE_TYPE_EVENT_DOWNSTREAM or
* @@GST_PAD_PROBE_TYPE_EVENT_UPSTREAM probe types.
* @GST_PAD_PROBE_TYPE_QUERY_DOWNSTREAM: probe downstream queries
* @GST_PAD_PROBE_TYPE_QUERY_UPSTREAM: probe upstream queries
* @GST_PAD_PROBE_TYPE_PUSH: probe push
* @GST_PAD_PROBE_TYPE_PULL: probe pull
*
* The different probing types that can occur. When either one of
* @GST_PAD_PROBE_TYPE_IDLE or @GST_PAD_PROBE_TYPE_BLOCK is used, the probe will be a
* blocking probe.
*/
typedef enum
{
GST_PAD_PROBE_TYPE_INVALID = 0,
/* flags to control blocking */
GST_PAD_PROBE_TYPE_IDLE = (1 << 0),
GST_PAD_PROBE_TYPE_BLOCK = (1 << 1),
/* flags to select datatypes */
GST_PAD_PROBE_TYPE_BUFFER = (1 << 4),
GST_PAD_PROBE_TYPE_BUFFER_LIST = (1 << 5),
GST_PAD_PROBE_TYPE_EVENT_DOWNSTREAM = (1 << 6),
GST_PAD_PROBE_TYPE_EVENT_UPSTREAM = (1 << 7),
GST_PAD_PROBE_TYPE_EVENT_FLUSH = (1 << 8),
GST_PAD_PROBE_TYPE_QUERY_DOWNSTREAM = (1 << 9),
GST_PAD_PROBE_TYPE_QUERY_UPSTREAM = (1 << 10),
/* flags to select scheduling mode */
GST_PAD_PROBE_TYPE_PUSH = (1 << 12),
GST_PAD_PROBE_TYPE_PULL = (1 << 13)
} GstPadProbeType;
#define GST_PAD_PROBE_TYPE_BLOCKING (GST_PAD_PROBE_TYPE_IDLE | GST_PAD_PROBE_TYPE_BLOCK)
#define GST_PAD_PROBE_TYPE_BLOCK_DOWNSTREAM (GST_PAD_PROBE_TYPE_BLOCK | GST_PAD_PROBE_TYPE_DATA_DOWNSTREAM)
#define GST_PAD_PROBE_TYPE_BLOCK_UPSTREAM (GST_PAD_PROBE_TYPE_BLOCK | GST_PAD_PROBE_TYPE_DATA_UPSTREAM)
#define GST_PAD_PROBE_TYPE_DATA_DOWNSTREAM (GST_PAD_PROBE_TYPE_BUFFER | GST_PAD_PROBE_TYPE_BUFFER_LIST | \
GST_PAD_PROBE_TYPE_EVENT_DOWNSTREAM)
#define GST_PAD_PROBE_TYPE_DATA_UPSTREAM (GST_PAD_PROBE_TYPE_EVENT_UPSTREAM)
#define GST_PAD_PROBE_TYPE_DATA_BOTH (GST_PAD_PROBE_TYPE_DATA_DOWNSTREAM | \
GST_PAD_PROBE_TYPE_DATA_UPSTREAM)
#define GST_PAD_PROBE_TYPE_EVENT_BOTH (GST_PAD_PROBE_TYPE_EVENT_DOWNSTREAM | \
GST_PAD_PROBE_TYPE_EVENT_UPSTREAM)
#define GST_PAD_PROBE_TYPE_QUERY_BOTH (GST_PAD_PROBE_TYPE_QUERY_DOWNSTREAM | \
GST_PAD_PROBE_TYPE_QUERY_UPSTREAM)
#define GST_PAD_PROBE_TYPE_ALL_BOTH (GST_PAD_PROBE_TYPE_DATA_BOTH | \
GST_PAD_PROBE_TYPE_QUERY_BOTH)
#define GST_PAD_PROBE_TYPE_SCHEDULING (GST_PAD_PROBE_TYPE_PUSH | GST_PAD_PROBE_TYPE_PULL)
/**
* GstPadProbeReturn:
* @GST_PAD_PROBE_OK: normal probe return value
* @GST_PAD_PROBE_DROP: drop data in data probes. For push mode this means that
* the data item is not sent downstream. For pull mode, it means that the
* data item is not passed upstream. In both cases, this result code
* returns #GST_FLOW_OK or %TRUE to the caller.
* @GST_PAD_PROBE_REMOVE: remove probe
* @GST_PAD_PROBE_PASS: pass the data item in the block probe and block on
* the next item
*
* Different return values for the #GstPadProbeCallback.
*/
typedef enum
{
GST_PAD_PROBE_DROP,
GST_PAD_PROBE_OK,
GST_PAD_PROBE_REMOVE,
GST_PAD_PROBE_PASS,
} GstPadProbeReturn;
/**
* GstPadProbeInfo:
* @type: the current probe type
* @id: the id of the probe
* @data: type specific data, check the @type field to know the datatype.
* This field can be NULL.
* @offset: offset of pull probe, this field is valid when @type contains
* #GST_PAD_PROBE_TYPE_PULL
* @size: size of pull probe, this field is valid when @type contains
* #GST_PAD_PROBE_TYPE_PULL
*
* Info passed in the #GstPadProbeCallback.
*/
struct _GstPadProbeInfo
{
GstPadProbeType type;
gulong id;
gpointer data;
guint64 offset;
guint size;
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
#define GST_PAD_PROBE_INFO_TYPE(d) ((d)->type)
#define GST_PAD_PROBE_INFO_ID(d) ((d)->id)
#define GST_PAD_PROBE_INFO_DATA(d) ((d)->data)
#define GST_PAD_PROBE_INFO_BUFFER(d) GST_BUFFER_CAST(GST_PAD_PROBE_INFO_DATA(d))
#define GST_PAD_PROBE_INFO_BUFFER_LIST(d) GST_BUFFER_LIST_CAST(GST_PAD_PROBE_INFO_DATA(d))
#define GST_PAD_PROBE_INFO_EVENT(d) GST_EVENT_CAST(GST_PAD_PROBE_INFO_DATA(d))
#define GST_PAD_PROBE_INFO_QUERY(d) GST_QUERY_CAST(GST_PAD_PROBE_INFO_DATA(d))
#define GST_PAD_PROBE_INFO_OFFSET(d) ((d)->offset)
#define GST_PAD_PROBE_INFO_SIZE(d) ((d)->size)
/**
* GstPadProbeCallback:
* @pad: the #GstPad that is blocked
* @info: #GstPadProbeInfo
* @user_data: the gpointer to optional user data.
*
* Callback used by gst_pad_add_probe(). Gets called to notify about the current
* blocking type.
*
* The callback is allowed to modify the data pointer in @info.
*/
typedef GstPadProbeReturn (*GstPadProbeCallback) (GstPad *pad, GstPadProbeInfo *info,
gpointer user_data);
/**
* GstPadStickyEventsForeachFunction:
* @pad: the #GstPad.
* @event: a sticky #GstEvent.
* @user_data: the #gpointer to optional user data.
*
* Callback used by gst_pad_sticky_events_foreach().
*
* When this function returns %TRUE, the next event will be
* returned. When %FALSE is returned, gst_pad_sticky_events_foreach() will return.
*
* When @event is set to NULL, the item will be removed from the list of sticky events.
* When @event has been made writable, the new buffer reference can be assigned
* to @event. This function is responsible for unreffing the old event when
* removing or modifying.
*
* Returns: %TRUE if the iteration should continue
*/
typedef gboolean (*GstPadStickyEventsForeachFunction) (GstPad *pad, GstEvent **event,
gpointer user_data);
/**
* GstPadFlags:
* @GST_PAD_FLAG_BLOCKED: is dataflow on a pad blocked
* @GST_PAD_FLAG_FLUSHING: is pad flushing
* @GST_PAD_FLAG_EOS: is pad in EOS state
* @GST_PAD_FLAG_BLOCKING: is pad currently blocking on a buffer or event
* @GST_PAD_FLAG_NEED_PARENT: ensure that there is a parent object before calling
* into the pad callbacks.
* @GST_PAD_FLAG_NEED_RECONFIGURE: the pad should be reconfigured/renegotiated.
* The flag has to be unset manually after
* reconfiguration happened.
* @GST_PAD_FLAG_PENDING_EVENTS: the pad has pending events
* @GST_PAD_FLAG_FIXED_CAPS: the pad is using fixed caps this means that once the
* caps are set on the pad, the caps query function only
* returns those caps.
* @GST_PAD_FLAG_PROXY_CAPS: the default event and query handler will forward
* all events and queries to the internally linked pads
* instead of discarding them.
* @GST_PAD_FLAG_PROXY_ALLOCATION: the default query handler will forward
* allocation queries to the internally linked pads
* instead of discarding them.
* @GST_PAD_FLAG_LAST: offset to define more flags
*
* Pad state flags
*/
typedef enum {
GST_PAD_FLAG_BLOCKED = (GST_OBJECT_FLAG_LAST << 0),
GST_PAD_FLAG_FLUSHING = (GST_OBJECT_FLAG_LAST << 1),
GST_PAD_FLAG_EOS = (GST_OBJECT_FLAG_LAST << 2),
GST_PAD_FLAG_BLOCKING = (GST_OBJECT_FLAG_LAST << 3),
GST_PAD_FLAG_NEED_PARENT = (GST_OBJECT_FLAG_LAST << 4),
GST_PAD_FLAG_NEED_RECONFIGURE = (GST_OBJECT_FLAG_LAST << 5),
GST_PAD_FLAG_PENDING_EVENTS = (GST_OBJECT_FLAG_LAST << 6),
GST_PAD_FLAG_FIXED_CAPS = (GST_OBJECT_FLAG_LAST << 7),
GST_PAD_FLAG_PROXY_CAPS = (GST_OBJECT_FLAG_LAST << 8),
GST_PAD_FLAG_PROXY_ALLOCATION = (GST_OBJECT_FLAG_LAST << 9),
/* padding */
GST_PAD_FLAG_LAST = (GST_OBJECT_FLAG_LAST << 16)
} GstPadFlags;
/**
* GstPad:
* @element_private: private data owned by the parent element
* @padtemplate: padtemplate for this pad
* @direction: the direction of the pad, cannot change after creating
* the pad.
*
* The #GstPad structure. Use the functions to update the variables.
*/
struct _GstPad {
GstObject object;
/*< public >*/
gpointer element_private;
GstPadTemplate *padtemplate;
GstPadDirection direction;
/*< private >*/
/* streaming rec_lock */
GRecMutex stream_rec_lock;
GstTask *task;
/* block cond, mutex is from the object */
GCond block_cond;
GHookList probes;
GstPadMode mode;
GstPadActivateFunction activatefunc;
gpointer activatedata;
GDestroyNotify activatenotify;
GstPadActivateModeFunction activatemodefunc;
gpointer activatemodedata;
GDestroyNotify activatemodenotify;
/* pad link */
GstPad *peer;
GstPadLinkFunction linkfunc;
gpointer linkdata;
GDestroyNotify linknotify;
GstPadUnlinkFunction unlinkfunc;
gpointer unlinkdata;
GDestroyNotify unlinknotify;
/* data transport functions */
GstPadChainFunction chainfunc;
gpointer chaindata;
GDestroyNotify chainnotify;
GstPadChainListFunction chainlistfunc;
gpointer chainlistdata;
GDestroyNotify chainlistnotify;
GstPadGetRangeFunction getrangefunc;
gpointer getrangedata;
GDestroyNotify getrangenotify;
GstPadEventFunction eventfunc;
gpointer eventdata;
GDestroyNotify eventnotify;
/* pad offset */
gint64 offset;
/* generic query method */
GstPadQueryFunction queryfunc;
gpointer querydata;
GDestroyNotify querynotify;
/* internal links */
GstPadIterIntLinkFunction iterintlinkfunc;
gpointer iterintlinkdata;
GDestroyNotify iterintlinknotify;
/* counts number of probes attached. */
gint num_probes;
gint num_blocked;
GstPadPrivate *priv;
gpointer _gst_reserved[GST_PADDING];
};
struct _GstPadClass {
GstObjectClass parent_class;
/* signal callbacks */
void (*linked) (GstPad *pad, GstPad *peer);
void (*unlinked) (GstPad *pad, GstPad *peer);
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
/***** helper macros *****/
/* GstPad */
#define GST_PAD_NAME(pad) (GST_OBJECT_NAME(pad))
#define GST_PAD_PARENT(pad) (GST_ELEMENT_CAST(GST_OBJECT_PARENT(pad)))
#define GST_PAD_ELEMENT_PRIVATE(pad) (GST_PAD_CAST(pad)->element_private)
#define GST_PAD_PAD_TEMPLATE(pad) (GST_PAD_CAST(pad)->padtemplate)
#define GST_PAD_DIRECTION(pad) (GST_PAD_CAST(pad)->direction)
#define GST_PAD_TASK(pad) (GST_PAD_CAST(pad)->task)
#define GST_PAD_MODE(pad) (GST_PAD_CAST(pad)->mode)
#define GST_PAD_ACTIVATEFUNC(pad) (GST_PAD_CAST(pad)->activatefunc)
#define GST_PAD_ACTIVATEMODEFUNC(pad) (GST_PAD_CAST(pad)->activatemodefunc)
#define GST_PAD_CHAINFUNC(pad) (GST_PAD_CAST(pad)->chainfunc)
#define GST_PAD_CHAINLISTFUNC(pad) (GST_PAD_CAST(pad)->chainlistfunc)
#define GST_PAD_GETRANGEFUNC(pad) (GST_PAD_CAST(pad)->getrangefunc)
#define GST_PAD_EVENTFUNC(pad) (GST_PAD_CAST(pad)->eventfunc)
#define GST_PAD_QUERYFUNC(pad) (GST_PAD_CAST(pad)->queryfunc)
#define GST_PAD_ITERINTLINKFUNC(pad) (GST_PAD_CAST(pad)->iterintlinkfunc)
#define GST_PAD_PEER(pad) (GST_PAD_CAST(pad)->peer)
#define GST_PAD_LINKFUNC(pad) (GST_PAD_CAST(pad)->linkfunc)
#define GST_PAD_UNLINKFUNC(pad) (GST_PAD_CAST(pad)->unlinkfunc)
#define GST_PAD_IS_SRC(pad) (GST_PAD_DIRECTION(pad) == GST_PAD_SRC)
#define GST_PAD_IS_SINK(pad) (GST_PAD_DIRECTION(pad) == GST_PAD_SINK)
#define GST_PAD_IS_LINKED(pad) (GST_PAD_PEER(pad) != NULL)
#define GST_PAD_IS_ACTIVE(pad) (GST_PAD_MODE(pad) != GST_PAD_MODE_NONE)
#define GST_PAD_IS_BLOCKED(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_BLOCKED))
#define GST_PAD_IS_BLOCKING(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_BLOCKING))
#define GST_PAD_IS_FLUSHING(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_FLUSHING))
#define GST_PAD_SET_FLUSHING(pad) (GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_FLUSHING))
#define GST_PAD_UNSET_FLUSHING(pad) (GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLAG_FLUSHING))
#define GST_PAD_IS_EOS(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_EOS))
#define GST_PAD_NEEDS_RECONFIGURE(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_NEED_RECONFIGURE))
#define GST_PAD_HAS_PENDING_EVENTS(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_PENDING_EVENTS))
#define GST_PAD_IS_FIXED_CAPS(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_FIXED_CAPS))
#define GST_PAD_NEEDS_PARENT(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_NEED_PARENT))
#define GST_PAD_IS_PROXY_CAPS(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_PROXY_CAPS))
#define GST_PAD_SET_PROXY_CAPS(pad) (GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_PROXY_CAPS))
#define GST_PAD_UNSET_PROXY_CAPS(pad) (GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLAG_PROXY_CAPS))
#define GST_PAD_IS_PROXY_ALLOCATION(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_PROXY_ALLOCATION))
#define GST_PAD_SET_PROXY_ALLOCATION(pad) (GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_PROXY_ALLOCATION))
#define GST_PAD_UNSET_PROXY_ALLOCATION(pad) (GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLAG_PROXY_ALLOCATION))
/**
* GST_PAD_GET_STREAM_LOCK:
* @pad: a #GstPad
*
* Get the stream lock of @pad. The stream lock is protecting the
* resources used in the data processing functions of @pad.
*/
#define GST_PAD_GET_STREAM_LOCK(pad) (&(GST_PAD_CAST(pad)->stream_rec_lock))
/**
* GST_PAD_STREAM_LOCK:
* @pad: a #GstPad
*
* Lock the stream lock of @pad.
*/
#define GST_PAD_STREAM_LOCK(pad) g_rec_mutex_lock(GST_PAD_GET_STREAM_LOCK(pad))
/**
* GST_PAD_STREAM_TRYLOCK:
* @pad: a #GstPad
*
* Try to Lock the stream lock of the pad, return TRUE if the lock could be
* taken.
*/
#define GST_PAD_STREAM_TRYLOCK(pad) g_rec_mutex_trylock(GST_PAD_GET_STREAM_LOCK(pad))
/**
* GST_PAD_STREAM_UNLOCK:
* @pad: a #GstPad
*
* Unlock the stream lock of @pad.
*/
#define GST_PAD_STREAM_UNLOCK(pad) g_rec_mutex_unlock(GST_PAD_GET_STREAM_LOCK(pad))
#define GST_PAD_BLOCK_GET_COND(pad) (&GST_PAD_CAST(pad)->block_cond)
#define GST_PAD_BLOCK_WAIT(pad) (g_cond_wait(GST_PAD_BLOCK_GET_COND (pad), GST_OBJECT_GET_LOCK (pad)))
#define GST_PAD_BLOCK_SIGNAL(pad) (g_cond_signal(GST_PAD_BLOCK_GET_COND (pad)))
#define GST_PAD_BLOCK_BROADCAST(pad) (g_cond_broadcast(GST_PAD_BLOCK_GET_COND (pad)))
GType gst_pad_get_type (void);
/* creating pads */
GstPad* gst_pad_new (const gchar *name, GstPadDirection direction);
GstPad* gst_pad_new_from_template (GstPadTemplate *templ, const gchar *name);
GstPad* gst_pad_new_from_static_template (GstStaticPadTemplate *templ, const gchar *name);
/**
* gst_pad_get_name:
* @pad: the pad to get the name from
*
* Get a copy of the name of the pad. g_free() after usage.
*
* MT safe.
*/
#define gst_pad_get_name(pad) gst_object_get_name (GST_OBJECT_CAST (pad))
/**
* gst_pad_get_parent:
* @pad: the pad to get the parent of
*
* Get the parent of @pad. This function increases the refcount
* of the parent object so you should gst_object_unref() it after usage.
* Can return NULL if the pad did not have a parent.
*
* MT safe.
*/
#define gst_pad_get_parent(pad) gst_object_get_parent (GST_OBJECT_CAST (pad))
GstPadDirection gst_pad_get_direction (GstPad *pad);
gboolean gst_pad_set_active (GstPad *pad, gboolean active);
gboolean gst_pad_is_active (GstPad *pad);
gboolean gst_pad_activate_mode (GstPad *pad, GstPadMode mode,
gboolean active);
gulong gst_pad_add_probe (GstPad *pad,
GstPadProbeType mask,
GstPadProbeCallback callback,
gpointer user_data,
GDestroyNotify destroy_data);
void gst_pad_remove_probe (GstPad *pad, gulong id);
gboolean gst_pad_is_blocked (GstPad *pad);
gboolean gst_pad_is_blocking (GstPad *pad);
void gst_pad_mark_reconfigure (GstPad *pad);
gboolean gst_pad_check_reconfigure (GstPad *pad);
void gst_pad_set_element_private (GstPad *pad, gpointer priv);
gpointer gst_pad_get_element_private (GstPad *pad);
GstPadTemplate* gst_pad_get_pad_template (GstPad *pad);
GstEvent* gst_pad_get_sticky_event (GstPad *pad, GstEventType event_type,
guint idx);
void gst_pad_sticky_events_foreach (GstPad *pad, GstPadStickyEventsForeachFunction foreach_func, gpointer user_data);
/* data passing setup functions */
void gst_pad_set_activate_function_full (GstPad *pad,
GstPadActivateFunction activate,
gpointer user_data,
GDestroyNotify notify);
void gst_pad_set_activatemode_function_full (GstPad *pad,
GstPadActivateModeFunction activatemode,
gpointer user_data,
GDestroyNotify notify);
/* data passing functions */
void gst_pad_set_chain_function_full (GstPad *pad,
GstPadChainFunction chain,
gpointer user_data,
GDestroyNotify notify);
void gst_pad_set_chain_list_function_full (GstPad *pad,
GstPadChainListFunction chainlist,
gpointer user_data,
GDestroyNotify notify);
void gst_pad_set_getrange_function_full (GstPad *pad,
GstPadGetRangeFunction get,
gpointer user_data,
GDestroyNotify notify);
void gst_pad_set_event_function_full (GstPad *pad,
GstPadEventFunction event,
gpointer user_data,
GDestroyNotify notify);
#define gst_pad_set_activate_function(p,f) gst_pad_set_activate_function_full((p),(f),NULL,NULL)
#define gst_pad_set_activatemode_function(p,f) gst_pad_set_activatemode_function_full((p),(f),NULL,NULL)
#define gst_pad_set_chain_function(p,f) gst_pad_set_chain_function_full((p),(f),NULL,NULL)
#define gst_pad_set_chain_list_function(p,f) gst_pad_set_chain_list_function_full((p),(f),NULL,NULL)
#define gst_pad_set_getrange_function(p,f) gst_pad_set_getrange_function_full((p),(f),NULL,NULL)
#define gst_pad_set_event_function(p,f) gst_pad_set_event_function_full((p),(f),NULL,NULL)
/* pad links */
void gst_pad_set_link_function_full (GstPad *pad,
GstPadLinkFunction link,
gpointer user_data,
GDestroyNotify notify);
void gst_pad_set_unlink_function_full (GstPad *pad,
GstPadUnlinkFunction unlink,
gpointer user_data,
GDestroyNotify notify);
#define gst_pad_set_link_function(p,f) gst_pad_set_link_function_full((p),(f),NULL,NULL)
#define gst_pad_set_unlink_function(p,f) gst_pad_set_unlink_function_full((p),(f),NULL,NULL)
gboolean gst_pad_can_link (GstPad *srcpad, GstPad *sinkpad);
GstPadLinkReturn gst_pad_link (GstPad *srcpad, GstPad *sinkpad);
GstPadLinkReturn gst_pad_link_full (GstPad *srcpad, GstPad *sinkpad, GstPadLinkCheck flags);
gboolean gst_pad_unlink (GstPad *srcpad, GstPad *sinkpad);
gboolean gst_pad_is_linked (GstPad *pad);
GstPad* gst_pad_get_peer (GstPad *pad);
GstCaps* gst_pad_get_pad_template_caps (GstPad *pad);
/* capsnego function for linked/unlinked pads */
GstCaps * gst_pad_get_current_caps (GstPad * pad);
gboolean gst_pad_has_current_caps (GstPad * pad);
gboolean gst_pad_set_caps (GstPad * pad, GstCaps *caps);
/* capsnego for linked pads */
GstCaps * gst_pad_get_allowed_caps (GstPad * pad);
/* pad offsets */
gint64 gst_pad_get_offset (GstPad *pad);
void gst_pad_set_offset (GstPad *pad, gint64 offset);
/* data passing functions to peer */
GstFlowReturn gst_pad_push (GstPad *pad, GstBuffer *buffer);
GstFlowReturn gst_pad_push_list (GstPad *pad, GstBufferList *list);
GstFlowReturn gst_pad_pull_range (GstPad *pad, guint64 offset, guint size,
GstBuffer **buffer);
gboolean gst_pad_push_event (GstPad *pad, GstEvent *event);
gboolean gst_pad_event_default (GstPad *pad, GstObject *parent,
GstEvent *event);
/* data passing functions on pad */
GstFlowReturn gst_pad_chain (GstPad *pad, GstBuffer *buffer);
GstFlowReturn gst_pad_chain_list (GstPad *pad, GstBufferList *list);
GstFlowReturn gst_pad_get_range (GstPad *pad, guint64 offset, guint size,
GstBuffer **buffer);
gboolean gst_pad_send_event (GstPad *pad, GstEvent *event);
/* pad tasks */
gboolean gst_pad_start_task (GstPad *pad, GstTaskFunction func,
gpointer data);
gboolean gst_pad_pause_task (GstPad *pad);
gboolean gst_pad_stop_task (GstPad *pad);
/* internal links */
void gst_pad_set_iterate_internal_links_function_full (GstPad * pad,
GstPadIterIntLinkFunction iterintlink,
gpointer user_data,
GDestroyNotify notify);
GstIterator * gst_pad_iterate_internal_links (GstPad * pad);
GstIterator * gst_pad_iterate_internal_links_default (GstPad * pad, GstObject *parent);
#define gst_pad_set_iterate_internal_links_function(p,f) gst_pad_set_iterate_internal_links_function_full((p),(f),NULL,NULL)
/* generic query function */
gboolean gst_pad_query (GstPad *pad, GstQuery *query);
gboolean gst_pad_peer_query (GstPad *pad, GstQuery *query);
void gst_pad_set_query_function_full (GstPad *pad, GstPadQueryFunction query,
gpointer user_data,
GDestroyNotify notify);
gboolean gst_pad_query_default (GstPad *pad, GstObject *parent,
GstQuery *query);
#define gst_pad_set_query_function(p,f) gst_pad_set_query_function_full((p),(f),NULL,NULL)
/* misc helper functions */
gboolean gst_pad_forward (GstPad *pad, GstPadForwardFunction forward,
gpointer user_data);
G_END_DECLS
#endif /* __GST_PAD_H__ */
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