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gstreamer/gst/gstpad.h
Wim Taymans 06addca012 pad: add PROXY_SCHEDULING flag 
Add a flag that makes the default query handler forward the scheduling query.
2012-07-18 17:49:32 +02:00

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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.
* @GST_FLOW_CUSTOM_SUCCESS_1: Pre-defined custom success code (define your
* custom success code to this to avoid compiler
* warnings).
* @GST_FLOW_CUSTOM_SUCCESS_2: Pre-defined custom success code.
* @GST_FLOW_CUSTOM_ERROR: Elements can use values starting from
* this (and lower) to define custom error codes.
* @GST_FLOW_CUSTOM_ERROR_1: Pre-defined custom error code (define your
* custom error code to this to avoid compiler
* warnings).
* @GST_FLOW_CUSTOM_ERROR_2: Pre-defined custom error code.
*
* The result of passing data to a pad.
*
* Note that the custom return values should not be exposed outside of the
* element scope.
*/
/* 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>
*/
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()).
*/
#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.
*/
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_PROXY_SCHEDULING: the default query handler will forward
* scheduling 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),
GST_PAD_FLAG_PROXY_SCHEDULING = (GST_OBJECT_FLAG_LAST << 10),
/* 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))
#define GST_PAD_IS_PROXY_SCHEDULING(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_PROXY_SCHEDULING))
#define GST_PAD_SET_PROXY_SCHEDULING(pad) (GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_PROXY_SCHEDULING))
#define GST_PAD_UNSET_PROXY_SCHEDULING(pad) (GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLAG_PROXY_SCHEDULING))
/**
* 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);
/* 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 user_data, GDestroyNotify notify);
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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