Jabber: initial version of Jingle support

1 files changed, 1576 insertions, 0 deletions

diff --git a/include/gst/gstpad.h b/include/gst/gstpad.h
new file mode 100644
index 0000000000..c89be30508
--- /dev/null
+++ b/include/gst/gstpad.h
@@ -0,0 +1,1576 @@
+/* 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., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, 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 <glib.h>
+
+GST_API
+const gchar   * gst_pad_mode_get_name (GstPadMode mode);
+
+#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 occurred. Element generating
+ *                               this error should post an error message using
+ *                               GST_ELEMENT_ERROR() 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.
+ */
+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;
+
+GST_API
+const gchar *         gst_flow_get_name (GstFlowReturn ret);
+
+GST_API
+GQuark                gst_flow_to_quark (GstFlowReturn ret);
+
+GST_API
+const gchar *         gst_pad_link_get_name (GstPadLinkReturn 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().
+ * @GST_PAD_LINK_CHECK_NO_RECONFIGURE: Disables pushing a reconfigure event when pads are
+ *   linked.
+ * @GST_PAD_LINK_CHECK_DEFAULT: The default checks done when linking
+ *   pads (i.e. the ones used by gst_pad_link()).
+ *
+ * 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.
+ *
+ * > 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.
+ */
+
+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,
+
+
+  /* Not really checks, more like flags
+   * Added here to avoid creating a new gst_pad_link_variant */
+  GST_PAD_LINK_CHECK_NO_RECONFIGURE = 1 << 3,
+
+  GST_PAD_LINK_CHECK_DEFAULT       = GST_PAD_LINK_CHECK_HIERARCHY | GST_PAD_LINK_CHECK_CAPS
+} GstPadLinkCheck;
+
+/* 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: (allow-none): 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: (transfer full): 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: (allow-none): 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: (transfer full): 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: (allow-none): 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_mode() with the
+ * #GST_PAD_MODE_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: (allow-none): 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: (transfer full): 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);
+
+/**
+ * GstPadEventFullFunction:
+ * @pad: the #GstPad to handle the event.
+ * @parent: (allow-none): 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: (transfer full): the #GstEvent to handle.
+ *
+ * Function signature to handle an event for the pad.
+ *
+ * This variant is for specific elements that will take into account the
+ * last downstream flow return (from a pad push), in which case they can
+ * return it.
+ *
+ * Returns: %GST_FLOW_OK if the event was handled properly, or any other
+ * #GstFlowReturn dependent on downstream state.
+ *
+ * Since: 1.8
+ */
+typedef GstFlowReturn		(*GstPadEventFullFunction)	(GstPad *pad, GstObject *parent,
+                                                                 GstEvent *event);
+
+
+/* internal links */
+/**
+ * GstPadIterIntLinkFunction:
+ * @pad: The #GstPad to query.
+ * @parent: (allow-none): 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: (allow-none): 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.
+ * @parent: (allow-none): 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.
+ * @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, GstObject *parent, GstPad *peer);
+/**
+ * GstPadUnlinkFunction:
+ * @pad: the #GstPad that is linked.
+ * @parent: (allow-none): 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.
+ *
+ * Function signature to handle a unlinking the pad prom its peer.
+ *
+ * The pad's lock is already held when the unlink function is called, so most
+ * pad functions cannot be called from within the callback.
+ */
+typedef void			(*GstPadUnlinkFunction)		(GstPad *pad, GstObject *parent);
+
+
+/* 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 while the callback is called
+ * @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
+ * @GST_PAD_PROBE_TYPE_BLOCKING: probe and block at the next opportunity, at data flow or when idle
+ * @GST_PAD_PROBE_TYPE_DATA_DOWNSTREAM: probe downstream data (buffers, buffer lists, and events)
+ * @GST_PAD_PROBE_TYPE_DATA_UPSTREAM: probe upstream data (events)
+ * @GST_PAD_PROBE_TYPE_DATA_BOTH: probe upstream and downstream data (buffers, buffer lists, and events)
+ * @GST_PAD_PROBE_TYPE_BLOCK_DOWNSTREAM: probe and block downstream data (buffers, buffer lists, and events)
+ * @GST_PAD_PROBE_TYPE_BLOCK_UPSTREAM: probe and block upstream data (events)
+ * @GST_PAD_PROBE_TYPE_EVENT_BOTH: probe upstream and downstream events
+ * @GST_PAD_PROBE_TYPE_QUERY_BOTH: probe upstream and downstream queries
+ * @GST_PAD_PROBE_TYPE_ALL_BOTH: probe upstream events and queries and downstream buffers, buffer lists, events and queries
+ * @GST_PAD_PROBE_TYPE_SCHEDULING: probe push and 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),
+
+  /* flag combinations */
+  GST_PAD_PROBE_TYPE_BLOCKING         = GST_PAD_PROBE_TYPE_IDLE | GST_PAD_PROBE_TYPE_BLOCK,
+  GST_PAD_PROBE_TYPE_DATA_DOWNSTREAM  = GST_PAD_PROBE_TYPE_BUFFER | GST_PAD_PROBE_TYPE_BUFFER_LIST | GST_PAD_PROBE_TYPE_EVENT_DOWNSTREAM,
+  GST_PAD_PROBE_TYPE_DATA_UPSTREAM    = GST_PAD_PROBE_TYPE_EVENT_UPSTREAM,
+  GST_PAD_PROBE_TYPE_DATA_BOTH        = GST_PAD_PROBE_TYPE_DATA_DOWNSTREAM | GST_PAD_PROBE_TYPE_DATA_UPSTREAM,
+  GST_PAD_PROBE_TYPE_BLOCK_DOWNSTREAM = GST_PAD_PROBE_TYPE_BLOCK | GST_PAD_PROBE_TYPE_DATA_DOWNSTREAM,
+  GST_PAD_PROBE_TYPE_BLOCK_UPSTREAM   = GST_PAD_PROBE_TYPE_BLOCK | GST_PAD_PROBE_TYPE_DATA_UPSTREAM,
+  GST_PAD_PROBE_TYPE_EVENT_BOTH       = GST_PAD_PROBE_TYPE_EVENT_DOWNSTREAM | GST_PAD_PROBE_TYPE_EVENT_UPSTREAM,
+  GST_PAD_PROBE_TYPE_QUERY_BOTH       = GST_PAD_PROBE_TYPE_QUERY_DOWNSTREAM | GST_PAD_PROBE_TYPE_QUERY_UPSTREAM,
+  GST_PAD_PROBE_TYPE_ALL_BOTH         = GST_PAD_PROBE_TYPE_DATA_BOTH | GST_PAD_PROBE_TYPE_QUERY_BOTH,
+  GST_PAD_PROBE_TYPE_SCHEDULING       = GST_PAD_PROBE_TYPE_PUSH | GST_PAD_PROBE_TYPE_PULL
+} GstPadProbeType;
+
+
+/**
+ * GstPadProbeReturn:
+ * @GST_PAD_PROBE_OK: normal probe return value. This leaves the probe in
+ *        place, and defers decisions about dropping or passing data to other
+ *        probes, if any. If there are no other probes, the default behaviour
+ *        for the probe type applies ('block' for blocking probes,
+ *        and 'pass' for non-blocking probes).
+ * @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, no other probes
+ *        are called for this item and %GST_FLOW_OK or %TRUE is returned to the
+ *        caller.
+ * @GST_PAD_PROBE_REMOVE: remove this probe, passing the data. For blocking probes
+ *        this will cause data flow to unblock, unless there are also other
+ *        blocking probes installed.
+ * @GST_PAD_PROBE_PASS: pass the data item in the block probe and block on the
+ *        next item. Note, that if there are multiple pad probes installed and
+ *        any probe returns PASS, the data will be passed.
+ * @GST_PAD_PROBE_HANDLED: Data has been handled in the probe and will not be
+ *        forwarded further. For events and buffers this is the same behaviour as
+ *        %GST_PAD_PROBE_DROP (except that in this case you need to unref the buffer
+ *        or event yourself). For queries it will also return %TRUE to the caller.
+ *        The probe can also modify the #GstFlowReturn value by using the
+ *        #GST_PAD_PROBE_INFO_FLOW_RETURN() accessor.
+ *        Note that the resulting query must contain valid entries.
+ *        Since: 1.6
+ *
+ * Different return values for the #GstPadProbeCallback.
+ */
+typedef enum
+{
+  GST_PAD_PROBE_DROP,
+  GST_PAD_PROBE_OK,
+  GST_PAD_PROBE_REMOVE,
+  GST_PAD_PROBE_PASS,
+  GST_PAD_PROBE_HANDLED
+} GstPadProbeReturn;
+
+
+/**
+ * GstPadProbeInfo:
+ * @type: the current probe type
+ * @id: the id of the probe
+ * @data: (allow-none): 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 >*/
+  union {
+    gpointer _gst_reserved[GST_PADDING];
+    struct {
+      GstFlowReturn flow_ret;
+    } abi;
+  } ABI;
+};
+
+#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_FLOW_RETURN(d)  ((d)->ABI.abi.flow_ret)
+
+#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)
+
+GST_API
+GstEvent*      gst_pad_probe_info_get_event       (GstPadProbeInfo * info);
+
+GST_API
+GstQuery*      gst_pad_probe_info_get_query       (GstPadProbeInfo * info);
+
+GST_API
+GstBuffer*     gst_pad_probe_info_get_buffer      (GstPadProbeInfo * info);
+
+GST_API
+GstBufferList* gst_pad_probe_info_get_buffer_list (GstPadProbeInfo * info);
+
+/**
+ * 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.
+ *
+ * Returns: a #GstPadProbeReturn
+ */
+typedef GstPadProbeReturn   (*GstPadProbeCallback)   (GstPad *pad, GstPadProbeInfo *info,
+                                                      gpointer user_data);
+
+/**
+ * GstPadStickyEventsForeachFunction:
+ * @pad: the #GstPad.
+ * @event: (allow-none): 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.
+ * @event can be replaced by assigning a new reference to it.
+ * 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 default caps query function
+ *     will only return 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_ACCEPT_INTERSECT: the default accept-caps handler will check
+ *                      it the caps intersect the query-caps result instead
+ *                      of checking for a subset. This is interesting for
+ *                      parsers that can accept incompletely specified caps.
+ * @GST_PAD_FLAG_ACCEPT_TEMPLATE: the default accept-caps handler will use
+ *                      the template pad caps instead of query caps to
+ *                      compare with the accept caps. Use this in combination
+ *                      with %GST_PAD_FLAG_ACCEPT_INTERSECT. (Since: 1.6)
+ * @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),
+  GST_PAD_FLAG_ACCEPT_INTERSECT = (GST_OBJECT_FLAG_LAST << 11),
+  GST_PAD_FLAG_ACCEPT_TEMPLATE  = (GST_OBJECT_FLAG_LAST << 12),
+  /* 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;
+
+  union {
+    gpointer _gst_reserved[GST_PADDING];
+    struct {
+      GstFlowReturn last_flowret;
+      GstPadEventFullFunction eventfullfunc;
+    } abi;
+  } ABI;
+};
+
+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 */
+
+/**
+ * GST_PAD_NAME:
+ * @pad: a #GstPad
+ *
+ * Get name of the given pad.
+ * No locking is performed in this function, use gst_pad_get_name() instead.
+ */
+#define GST_PAD_NAME(pad)		(GST_OBJECT_NAME(pad))
+/**
+ * GST_PAD_PARENT:
+ * @pad: a #GstPad
+ *
+ * Get the @pad parent.
+ * No locking is performed in this function, use gst_pad_get_parent() instead.
+ */
+#define GST_PAD_PARENT(pad)		(GST_ELEMENT_CAST(GST_OBJECT_PARENT(pad)))
+/**
+ * GST_PAD_ELEMENT_PRIVATE:
+ * @pad: a #GstPad
+ *
+ * Get the private data of @pad, which is usually some pad- or stream-specific
+ * structure created by the element and set on the pad when creating it.
+ * No locking is performed in this function.
+ */
+#define GST_PAD_ELEMENT_PRIVATE(pad)    (GST_PAD_CAST(pad)->element_private)
+/**
+ * GST_PAD_PAD_TEMPLATE:
+ * @pad: a #GstPad
+ *
+ * Get the @pad #GstPadTemplate. It describes the possible media types
+ * a @pad or an element factory can handle.
+ */
+#define GST_PAD_PAD_TEMPLATE(pad)	(GST_PAD_CAST(pad)->padtemplate)
+/**
+ * GST_PAD_DIRECTION:
+ * @pad: a #GstPad
+ *
+ * Get the #GstPadDirection of the given @pad. Accessor macro, use
+ * gst_pad_get_direction() instead.
+ */
+#define GST_PAD_DIRECTION(pad)		(GST_PAD_CAST(pad)->direction)
+/**
+ * GST_PAD_TASK:
+ * @pad: a #GstPad
+ *
+ * Get the #GstTask of @pad. Accessor macro used by GStreamer. Use the
+ * gst_pad_start_task(), gst_pad_stop_task() and gst_pad_pause_task()
+ * functions instead.
+ */
+#define GST_PAD_TASK(pad)		(GST_PAD_CAST(pad)->task)
+/**
+ * GST_PAD_MODE:
+ * @pad: a #GstPad
+ *
+ * Get the #GstPadMode of pad, which will be GST_PAD_MODE_NONE if the pad
+ * has not been activated yet, and otherwise either GST_PAD_MODE_PUSH or
+ * GST_PAD_MODE_PULL depending on which mode the pad was activated in.
+ */
+#define GST_PAD_MODE(pad)	        (GST_PAD_CAST(pad)->mode)
+/**
+ * GST_PAD_ACTIVATEFUNC:
+ * @pad: a #GstPad
+ *
+ * Get the #GstPadActivateFunction from @pad.
+ */
+#define GST_PAD_ACTIVATEFUNC(pad)	(GST_PAD_CAST(pad)->activatefunc)
+/**
+ * GST_PAD_ACTIVATEMODEFUNC:
+ * @pad: a #GstPad
+ *
+ * Get the #GstPadActivateModeFunction from the given @pad.
+ */
+#define GST_PAD_ACTIVATEMODEFUNC(pad)	(GST_PAD_CAST(pad)->activatemodefunc)
+/**
+ * GST_PAD_CHAINFUNC:
+ * @pad: a #GstPad
+ *
+ * Get the #GstPadChainFunction from the given @pad.
+ */
+#define GST_PAD_CHAINFUNC(pad)		(GST_PAD_CAST(pad)->chainfunc)
+/**
+ * GST_PAD_CHAINLISTFUNC:
+ * @pad: a #GstPad
+ *
+ * Get the #GstPadChainListFunction from the given @pad.
+ */
+#define GST_PAD_CHAINLISTFUNC(pad)      (GST_PAD_CAST(pad)->chainlistfunc)
+/**
+ * GST_PAD_GETRANGEFUNC:
+ * @pad: a #GstPad
+ *
+ * Get the #GstPadGetRangeFunction from the given @pad.
+ */
+#define GST_PAD_GETRANGEFUNC(pad)	(GST_PAD_CAST(pad)->getrangefunc)
+/**
+ * GST_PAD_EVENTFUNC:
+ * @pad: a #GstPad
+ *
+ * Get the #GstPadEventFunction from the given @pad, which
+ * is the function that handles events on the pad. You can
+ * use this to set your own event handling function on a pad
+ * after you create it.  If your element derives from a base
+ * class, use the base class's virtual functions instead.
+ */
+#define GST_PAD_EVENTFUNC(pad)		(GST_PAD_CAST(pad)->eventfunc)
+/**
+ * GST_PAD_EVENTFULLFUNC:
+ * @pad: a #GstPad
+ *
+ * Get the #GstPadEventFullFunction from the given @pad, which
+ * is the function that handles events on the pad. You can
+ * use this to set your own event handling function on a pad
+ * after you create it.  If your element derives from a base
+ * class, use the base class's virtual functions instead.
+ *
+ * Since: 1.8
+ */
+#define GST_PAD_EVENTFULLFUNC(pad)	(GST_PAD_CAST(pad)->ABI.abi.eventfullfunc)
+/**
+ * GST_PAD_QUERYFUNC:
+ * @pad: a #GstPad
+ *
+ * Get the #GstPadQueryFunction from @pad, which is the function
+ * that handles queries on the pad. You can  use this to set your
+ * own query handling function on a pad after you create it. If your
+ * element derives from a base class, use the base class's virtual
+ * functions instead.
+ */
+#define GST_PAD_QUERYFUNC(pad)		(GST_PAD_CAST(pad)->queryfunc)
+/**
+ * GST_PAD_ITERINTLINKFUNC:
+ * @pad: a #GstPad
+ *
+ * Get the #GstPadIterIntLinkFunction from the given @pad.
+ */
+#define GST_PAD_ITERINTLINKFUNC(pad)    (GST_PAD_CAST(pad)->iterintlinkfunc)
+/**
+ * GST_PAD_PEER:
+ * @pad: a #GstPad
+ *
+ * Return the pad's peer member. This member is a pointer to the linked @pad.
+ * No locking is performed in this function, use gst_pad_get_peer() instead.
+ */
+#define GST_PAD_PEER(pad)		(GST_PAD_CAST(pad)->peer)
+/**
+ * GST_PAD_LINKFUNC:
+ * @pad: a #GstPad
+ *
+ * Get the #GstPadLinkFunction for the given @pad.
+ */
+#define GST_PAD_LINKFUNC(pad)		(GST_PAD_CAST(pad)->linkfunc)
+/**
+ * GST_PAD_UNLINKFUNC:
+ * @pad: a #GstPad
+ *
+ * Get the #GstPadUnlinkFunction from the given @pad.
+ */
+#define GST_PAD_UNLINKFUNC(pad)		(GST_PAD_CAST(pad)->unlinkfunc)
+/**
+ * GST_PAD_IS_SRC:
+ * @pad: a #GstPad
+ *
+ * Returns: %TRUE if the pad is a source pad (i.e. produces data).
+ */
+#define GST_PAD_IS_SRC(pad)		(GST_PAD_DIRECTION(pad) == GST_PAD_SRC)
+/**
+ * GST_PAD_IS_SINK:
+ * @pad: a #GstPad
+ *
+ * Returns: %TRUE if the pad is a sink pad (i.e. consumes data).
+ */
+#define GST_PAD_IS_SINK(pad)		(GST_PAD_DIRECTION(pad) == GST_PAD_SINK)
+/**
+ * GST_PAD_IS_LINKED:
+ * @pad: a #GstPad
+ *
+ * Returns: %TRUE if the pad is linked to another pad. Use gst_pad_is_linked()
+ * instead.
+ */
+#define GST_PAD_IS_LINKED(pad)		(GST_PAD_PEER(pad) != NULL)
+/**
+ * GST_PAD_IS_ACTIVE:
+ * @pad: a #GstPad
+ *
+ * Returns: %TRUE if the pad has been activated.
+ */
+#define GST_PAD_IS_ACTIVE(pad)          (GST_PAD_MODE(pad) != GST_PAD_MODE_NONE)
+/**
+ * GST_PAD_IS_BLOCKED:
+ * @pad: a #GstPad
+ *
+ * Check if the dataflow on a @pad is blocked. Use gst_pad_is_blocked() instead.
+ */
+#define GST_PAD_IS_BLOCKED(pad)		(GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_BLOCKED))
+/**
+ * GST_PAD_IS_BLOCKING:
+ * @pad: a #GstPad
+ *
+ * Check if the @pad is currently blocking on a buffer or event. Use
+ * gst_pad_is_blocking() instead.
+ */
+#define GST_PAD_IS_BLOCKING(pad)	(GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_BLOCKING))
+/**
+ * GST_PAD_IS_FLUSHING:
+ * @pad: a #GstPad
+ *
+ * Check if the given @pad is flushing.
+ */
+#define GST_PAD_IS_FLUSHING(pad)	(GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_FLUSHING))
+/**
+ * GST_PAD_SET_FLUSHING:
+ * @pad: a #GstPad
+ *
+ * Set the given @pad to flushing state, which means it will not accept any
+ * more events, queries or buffers, and return GST_FLOW_FLUSHING if any buffers
+ * are pushed on it. This usually happens when the pad is shut down or when
+ * a flushing seek happens. This is used inside GStreamer when flush start/stop
+ * events pass through pads, or when an element state is changed and pads are
+ * activated or deactivated.
+ */
+#define GST_PAD_SET_FLUSHING(pad)	(GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_FLUSHING))
+/**
+ * GST_PAD_UNSET_FLUSHING:
+ * @pad: a #GstPad
+ *
+ * Unset the flushing flag.
+ */
+#define GST_PAD_UNSET_FLUSHING(pad)	(GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLAG_FLUSHING))
+/**
+ * GST_PAD_IS_EOS:
+ * @pad: a #GstPad
+ *
+ * Check if the @pad is in EOS state.
+ */
+#define GST_PAD_IS_EOS(pad)	        (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_EOS))
+/**
+ * GST_PAD_NEEDS_RECONFIGURE:
+ * @pad: a #GstPad
+ *
+ * Check if the @pad should be reconfigured/renegotiated.
+ * The flag has to be unset manually after reconfiguration happened.
+ * Use gst_pad_needs_reconfigure() or gst_pad_check_reconfigure() instead.
+ */
+#define GST_PAD_NEEDS_RECONFIGURE(pad)  (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_NEED_RECONFIGURE))
+/**
+ * GST_PAD_HAS_PENDING_EVENTS:
+ * @pad: a #GstPad
+ *
+ * Check if the given @pad has pending events. This is used internally by
+ * GStreamer.
+ */
+#define GST_PAD_HAS_PENDING_EVENTS(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_PENDING_EVENTS))
+/**
+ * GST_PAD_IS_FIXED_CAPS:
+ * @pad: a #GstPad
+ *
+ * Check if the given @pad is using fixed caps, which means that
+ * once the caps are set on the @pad, the caps query function will
+ * only return those caps. See gst_pad_use_fixed_caps().
+ */
+#define GST_PAD_IS_FIXED_CAPS(pad)	(GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_FIXED_CAPS))
+/**
+ * GST_PAD_NEEDS_PARENT:
+ * @pad: a #GstPad
+ *
+ * Check if there is a parent object before calling into the @pad callbacks.
+ * This is used internally by GStreamer.
+ */
+#define GST_PAD_NEEDS_PARENT(pad)       (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_NEED_PARENT))
+/**
+ * GST_PAD_IS_PROXY_CAPS:
+ * @pad: a #GstPad
+ *
+ * Check if the given @pad is set to proxy caps. This means that the default
+ * event and query handler will forward all events and queries to the
+ * internally linked @pads instead of discarding them.
+ */
+#define GST_PAD_IS_PROXY_CAPS(pad)      (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_PROXY_CAPS))
+/**
+ * GST_PAD_SET_PROXY_CAPS:
+ * @pad: a #GstPad
+ *
+ * Set @pad to proxy caps, so that all caps-related events and queries are
+ * proxied down- or upstream to the other side of the element automatically.
+ * Set this if the element always outputs data in the exact same format as it
+ * receives as input. This is just for convenience to avoid implementing some
+ * standard event and query handling code in an element.
+ */
+#define GST_PAD_SET_PROXY_CAPS(pad)     (GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_PROXY_CAPS))
+/**
+ * GST_PAD_UNSET_PROXY_CAPS:
+ * @pad: a #GstPad
+ *
+ * Unset proxy caps flag.
+ */
+#define GST_PAD_UNSET_PROXY_CAPS(pad)   (GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLAG_PROXY_CAPS))
+/**
+ * GST_PAD_IS_PROXY_ALLOCATION:
+ * @pad: a #GstPad
+ *
+ * Check if the given @pad is set as proxy allocation which means
+ * that the default query handler will forward allocation queries to the
+ * internally linked @pads instead of discarding them.
+ */
+#define GST_PAD_IS_PROXY_ALLOCATION(pad)    (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_PROXY_ALLOCATION))
+/**
+ * GST_PAD_SET_PROXY_ALLOCATION:
+ * @pad: a #GstPad
+ *
+ * Set @pad to proxy allocation queries, which means that the default query
+ * handler will forward allocation queries to the internally linked @pads
+ * instead of discarding them.
+ * Set this if the element always outputs data in the exact same format as it
+ * receives as input. This is just for convenience to avoid implementing some
+ * standard query handling code in an element.
+ */
+#define GST_PAD_SET_PROXY_ALLOCATION(pad)   (GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_PROXY_ALLOCATION))
+/**
+ * GST_PAD_UNSET_PROXY_ALLOCATION:
+ * @pad: a #GstPad
+ *
+ * Unset proxy allocation flag.
+ */
+#define GST_PAD_UNSET_PROXY_ALLOCATION(pad) (GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLAG_PROXY_ALLOCATION))
+/**
+ * GST_PAD_IS_PROXY_SCHEDULING:
+ * @pad: a #GstPad
+ *
+ * Check if the given @pad is set to proxy scheduling queries, which means that
+ * the default query handler will forward scheduling queries to the internally
+ * linked @pads instead of discarding them.
+ */
+#define GST_PAD_IS_PROXY_SCHEDULING(pad)    (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_PROXY_SCHEDULING))
+/**
+ * GST_PAD_SET_PROXY_SCHEDULING:
+ * @pad: a #GstPad
+ *
+ * Set @pad to proxy scheduling queries, which means that the default query
+ * handler will forward scheduling queries to the internally linked @pads
+ * instead of discarding them. You will usually want to handle scheduling
+ * queries explicitly if your element supports multiple scheduling modes.
+ */
+#define GST_PAD_SET_PROXY_SCHEDULING(pad)   (GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_PROXY_SCHEDULING))
+/**
+ * GST_PAD_UNSET_PROXY_SCHEDULING:
+ * @pad: a #GstPad
+ *
+ * Unset proxy scheduling flag.
+ */
+#define GST_PAD_UNSET_PROXY_SCHEDULING(pad) (GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLAG_PROXY_SCHEDULING))
+/**
+ * GST_PAD_IS_ACCEPT_INTERSECT:
+ * @pad: a #GstPad
+ *
+ * Check if the pad's accept intersect flag is set. The default accept-caps
+ * handler will check if the caps intersect the query-caps result instead of
+ * checking for a subset. This is interesting for parser elements that can
+ * accept incompletely specified caps.
+ */
+#define GST_PAD_IS_ACCEPT_INTERSECT(pad)    (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_ACCEPT_INTERSECT))
+/**
+ * GST_PAD_SET_ACCEPT_INTERSECT:
+ * @pad: a #GstPad
+ *
+ * Set @pad to by default accept caps by intersecting the result instead of
+ * checking for a subset. This is interesting for parser elements that can
+ * accept incompletely specified caps.
+ */
+#define GST_PAD_SET_ACCEPT_INTERSECT(pad)   (GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_ACCEPT_INTERSECT))
+/**
+ * GST_PAD_UNSET_ACCEPT_INTERSECT:
+ * @pad: a #GstPad
+ *
+ * Unset accept intersect flag.
+ */
+#define GST_PAD_UNSET_ACCEPT_INTERSECT(pad) (GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLAG_ACCEPT_INTERSECT))
+/**
+ * GST_PAD_IS_ACCEPT_TEMPLATE:
+ * @pad: a #GstPad
+ *
+ * Check if the pad's accept caps operation will use the pad template caps.
+ * The default accept-caps will do a query caps to get the caps, which might
+ * be querying downstream causing unnecessary overhead. It is recommended to
+ * implement a proper accept-caps query handler or to use this flag to prevent
+ * recursive accept-caps handling.
+ *
+ * Since: 1.6
+ */
+#define GST_PAD_IS_ACCEPT_TEMPLATE(pad)    (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLAG_ACCEPT_TEMPLATE))
+/**
+ * GST_PAD_SET_ACCEPT_TEMPLATE:
+ * @pad: a #GstPad
+ *
+ * Set @pad to by default use the pad template caps to compare with
+ * the accept caps instead of using a caps query result.
+ *
+ * Since: 1.6
+ */
+#define GST_PAD_SET_ACCEPT_TEMPLATE(pad)   (GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_ACCEPT_TEMPLATE))
+/**
+ * GST_PAD_UNSET_ACCEPT_TEMPLATE:
+ * @pad: a #GstPad
+ *
+ * Unset accept template flag.
+ *
+ * Since: 1.6
+ */
+#define GST_PAD_UNSET_ACCEPT_TEMPLATE(pad) (GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLAG_ACCEPT_TEMPLATE))
+/**
+ * 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. Accessor
+ * macro, use GST_PAD_STREAM_LOCK() and GST_PAD_STREAM_UNLOCK() instead
+ * to take/release the pad's stream lock.
+ */
+#define GST_PAD_GET_STREAM_LOCK(pad)    (&(GST_PAD_CAST(pad)->stream_rec_lock))
+/**
+ * GST_PAD_STREAM_LOCK:
+ * @pad: a #GstPad
+ *
+ * Take the pad's stream lock. The stream lock is recursive and will be taken
+ * when buffers or serialized downstream events are pushed on a 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 take the pad's stream lock, and return %TRUE if the lock could be
+ * taken, and otherwise %FALSE.
+ */
+#define GST_PAD_STREAM_TRYLOCK(pad)     g_rec_mutex_trylock(GST_PAD_GET_STREAM_LOCK(pad))
+/**
+ * GST_PAD_STREAM_UNLOCK:
+ * @pad: a #GstPad
+ *
+ * Release the pad's stream lock.
+ */
+#define GST_PAD_STREAM_UNLOCK(pad)      g_rec_mutex_unlock(GST_PAD_GET_STREAM_LOCK(pad))
+/**
+ * GST_PAD_LAST_FLOW_RETURN:
+ * @pad: a #GstPad
+ *
+ * Gets the last flow return on this pad
+ *
+ * Since: 1.4
+ */
+#define GST_PAD_LAST_FLOW_RETURN(pad)   (GST_PAD_CAST(pad)->ABI.abi.last_flowret)
+
+#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)))
+
+GST_API
+GType			gst_pad_get_type			(void);
+
+/* creating pads */
+
+GST_API
+GstPad*			gst_pad_new				(const gchar *name, GstPadDirection direction);
+
+GST_API
+GstPad*			gst_pad_new_from_template		(GstPadTemplate *templ, const gchar *name);
+
+GST_API
+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.
+ *
+ * Returns: (nullable): the parent
+ */
+#define gst_pad_get_parent(pad) gst_object_get_parent (GST_OBJECT_CAST (pad))
+
+GST_API
+GstPadDirection		gst_pad_get_direction			(GstPad *pad);
+
+GST_API
+gboolean		gst_pad_set_active			(GstPad *pad, gboolean active);
+
+GST_API
+gboolean		gst_pad_is_active			(GstPad *pad);
+
+GST_API
+gboolean		gst_pad_activate_mode			(GstPad *pad, GstPadMode mode,
+                                                                 gboolean active);
+GST_API
+gulong                  gst_pad_add_probe                       (GstPad *pad,
+								 GstPadProbeType mask,
+								 GstPadProbeCallback callback,
+                                                                 gpointer user_data,
+                                                                 GDestroyNotify destroy_data);
+GST_API
+void                    gst_pad_remove_probe                    (GstPad *pad, gulong id);
+
+GST_API
+gboolean		gst_pad_is_blocked			(GstPad *pad);
+
+GST_API
+gboolean		gst_pad_is_blocking			(GstPad *pad);
+
+GST_API
+void                    gst_pad_mark_reconfigure                (GstPad *pad);
+
+GST_API
+gboolean		gst_pad_needs_reconfigure               (GstPad *pad);
+
+GST_API
+gboolean		gst_pad_check_reconfigure               (GstPad *pad);
+
+GST_API
+void			gst_pad_set_element_private		(GstPad *pad, gpointer priv);
+
+GST_API
+gpointer		gst_pad_get_element_private		(GstPad *pad);
+
+GST_API
+GstPadTemplate*		gst_pad_get_pad_template		(GstPad *pad);
+
+GST_API
+GstFlowReturn           gst_pad_store_sticky_event              (GstPad *pad, GstEvent *event);
+
+GST_API
+GstEvent*               gst_pad_get_sticky_event                (GstPad *pad, GstEventType event_type,
+                                                                 guint idx);
+
+GST_API
+void                    gst_pad_sticky_events_foreach           (GstPad *pad, GstPadStickyEventsForeachFunction foreach_func, gpointer user_data);
+
+/* data passing setup functions */
+
+GST_API
+void			gst_pad_set_activate_function_full	(GstPad *pad,
+                                                                 GstPadActivateFunction activate,
+                                                                 gpointer user_data,
+                                                                 GDestroyNotify notify);
+GST_API
+void			gst_pad_set_activatemode_function_full	(GstPad *pad,
+                                                                 GstPadActivateModeFunction activatemode,
+                                                                 gpointer user_data,
+                                                                 GDestroyNotify notify);
+/* data passing functions */
+
+GST_API
+void			gst_pad_set_chain_function_full		(GstPad *pad,
+                                                                 GstPadChainFunction chain,
+                                                                 gpointer user_data,
+                                                                 GDestroyNotify notify);
+GST_API
+void			gst_pad_set_chain_list_function_full	(GstPad *pad,
+                                                                 GstPadChainListFunction chainlist,
+                                                                 gpointer user_data,
+                                                                 GDestroyNotify notify);
+GST_API
+void			gst_pad_set_getrange_function_full	(GstPad *pad,
+                                                                 GstPadGetRangeFunction get,
+                                                                 gpointer user_data,
+                                                                 GDestroyNotify notify);
+GST_API
+void			gst_pad_set_event_function_full		(GstPad *pad,
+                                                                 GstPadEventFunction event,
+                                                                 gpointer user_data,
+                                                                 GDestroyNotify notify);
+GST_API
+void			gst_pad_set_event_full_function_full	(GstPad *pad,
+                                                                 GstPadEventFullFunction 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)
+#define gst_pad_set_event_full_function(p,f)    gst_pad_set_event_full_function_full((p),(f),NULL,NULL)
+
+/* pad links */
+
+GST_API
+void			gst_pad_set_link_function_full		(GstPad *pad,
+                                                                 GstPadLinkFunction link,
+                                                                 gpointer user_data,
+                                                                 GDestroyNotify notify);
+GST_API
+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)
+
+GST_API
+gboolean                gst_pad_can_link                        (GstPad *srcpad, GstPad *sinkpad);
+
+GST_API
+GstPadLinkReturn        gst_pad_link				(GstPad *srcpad, GstPad *sinkpad);
+
+GST_API
+GstPadLinkReturn        gst_pad_link_full			(GstPad *srcpad, GstPad *sinkpad, GstPadLinkCheck flags);
+
+GST_API
+gboolean		gst_pad_unlink				(GstPad *srcpad, GstPad *sinkpad);
+
+GST_API
+gboolean		gst_pad_is_linked			(GstPad *pad);
+
+GST_API
+GstPad*			gst_pad_get_peer			(GstPad *pad);
+
+GST_API
+GstCaps*                gst_pad_get_pad_template_caps		(GstPad *pad);
+
+/* capsnego function for linked/unlinked pads */
+
+GST_API
+GstCaps *		gst_pad_get_current_caps                (GstPad * pad);
+
+GST_API
+gboolean		gst_pad_has_current_caps                (GstPad * pad);
+
+/* capsnego for linked pads */
+
+GST_API
+GstCaps *		gst_pad_get_allowed_caps		(GstPad * pad);
+
+/* pad offsets */
+
+GST_API
+gint64                  gst_pad_get_offset                      (GstPad *pad);
+
+GST_API
+void                    gst_pad_set_offset                      (GstPad *pad, gint64 offset);
+
+/* data passing functions to peer */
+
+GST_API
+GstFlowReturn		gst_pad_push				(GstPad *pad, GstBuffer *buffer);
+
+GST_API
+GstFlowReturn		gst_pad_push_list			(GstPad *pad, GstBufferList *list);
+
+GST_API
+GstFlowReturn		gst_pad_pull_range			(GstPad *pad, guint64 offset, guint size,
+								 GstBuffer **buffer);
+GST_API
+gboolean		gst_pad_push_event			(GstPad *pad, GstEvent *event);
+
+GST_API
+gboolean		gst_pad_event_default			(GstPad *pad, GstObject *parent,
+                                                                 GstEvent *event);
+GST_API
+GstFlowReturn           gst_pad_get_last_flow_return            (GstPad *pad);
+
+/* data passing functions on pad */
+
+GST_API
+GstFlowReturn		gst_pad_chain				(GstPad *pad, GstBuffer *buffer);
+
+GST_API
+GstFlowReturn		gst_pad_chain_list                      (GstPad *pad, GstBufferList *list);
+
+GST_API
+GstFlowReturn		gst_pad_get_range			(GstPad *pad, guint64 offset, guint size,
+								 GstBuffer **buffer);
+GST_API
+gboolean		gst_pad_send_event			(GstPad *pad, GstEvent *event);
+
+/* pad tasks */
+
+GST_API
+gboolean		gst_pad_start_task			(GstPad *pad, GstTaskFunction func,
+								 gpointer user_data, GDestroyNotify notify);
+GST_API
+gboolean		gst_pad_pause_task			(GstPad *pad);
+
+GST_API
+gboolean		gst_pad_stop_task			(GstPad *pad);
+
+GST_API
+GstTaskState	gst_pad_get_task_state		(GstPad *pad);
+
+/* internal links */
+
+GST_API
+void                    gst_pad_set_iterate_internal_links_function_full (GstPad * pad,
+                                                                 GstPadIterIntLinkFunction iterintlink,
+                                                                 gpointer user_data,
+                                                                 GDestroyNotify notify);
+
+GST_API
+GstIterator *           gst_pad_iterate_internal_links          (GstPad * pad);
+
+GST_API
+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)
+
+GST_API
+GstPad *                gst_pad_get_single_internal_link        (GstPad * pad);
+
+/* generic query function */
+
+GST_API
+gboolean		gst_pad_query				(GstPad *pad, GstQuery *query);
+
+GST_API
+gboolean		gst_pad_peer_query			(GstPad *pad, GstQuery *query);
+
+GST_API
+void			gst_pad_set_query_function_full		(GstPad *pad, GstPadQueryFunction query,
+                                                                 gpointer user_data,
+                                                                 GDestroyNotify notify);
+GST_API
+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 */
+
+GST_API
+gboolean		gst_pad_forward                         (GstPad *pad, GstPadForwardFunction forward,
+								 gpointer user_data);
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstPad, gst_object_unref)
+
+G_END_DECLS
+
+#endif /* __GST_PAD_H__ */