gstreamer/gst/gstpad.h
Wim Taymans 37a127d9ed - Make the return GList of gst_element_get_pad_list as const
Original commit message from CVS:
- Make the return GList of gst_element_get_pad_list as const
- Pad scheduler refactoring
- Remove gst_pad_set/unset_scheduler as it's not needed
- Reimplement gst_pad_get_scheduler using the parent scheduler
- Remove gst_pad_peek as it cannot work reliably
- Remove the pad bufpen, replace with scheduler private gpointer
- Make queue use the new _get_scheduler implementation
- Remove _pad_unset_scheduler from GstScheduler
- Remove LOOP_SEEK mode from aggregator
- Other fixes for API changes.
2002-09-12 20:52:03 +00:00

505 lines
19 KiB
C

/* 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>
#include <gst/gstobject.h>
#include <gst/gstbuffer.h>
#include <gst/gstcaps.h>
#include <gst/gstevent.h>
G_BEGIN_DECLS
extern GType _gst_pad_type;
extern GType _gst_real_pad_type;
extern GType _gst_ghost_pad_type;
#define GST_TYPE_PARANOID
/*
* Pad base class
*/
#define GST_TYPE_PAD (_gst_pad_type)
#define GST_PAD_CAST(obj) ((GstPad*)(obj))
#define GST_PAD_CLASS_CAST(klass) ((GstPadClass*)(klass))
#define GST_IS_PAD(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_PAD))
#define GST_IS_PAD_FAST(obj) (G_OBJECT_TYPE(obj) == GST_TYPE_REAL_PAD || \
G_OBJECT_TYPE(obj) == GST_TYPE_GHOST_PAD)
#define GST_IS_PAD_CLASS(obj) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_PAD))
#ifdef GST_TYPE_PARANOID
# 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))
#else
# define GST_PAD GST_PAD_CAST
# define GST_PAD_CLASS GST_PAD_CLASS_CAST
#endif
/*
* Real Pads
*/
#define GST_TYPE_REAL_PAD (_gst_real_pad_type)
#define GST_REAL_PAD_CAST(obj) ((GstRealPad*)(obj))
#define GST_REAL_PAD_CLASS_CAST(klass) ((GstRealPadClass*)(klass))
#define GST_IS_REAL_PAD(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_REAL_PAD))
#define GST_IS_REAL_PAD_FAST(obj) (G_OBJECT_TYPE(obj) == GST_TYPE_REAL_PAD)
#define GST_IS_REAL_PAD_CLASS(obj) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_REAL_PAD))
#ifdef GST_TYPE_PARANOID
# define GST_REAL_PAD(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_REAL_PAD, GstRealPad))
# define GST_REAL_PAD_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_REAL_PAD, GstRealPadClass))
#else
# define GST_REAL_PAD GST_REAL_PAD_CAST
# define GST_REAL_PAD_CLASS GST_REAL_PAD_CLASS_CAST
#endif
/*
* Ghost Pads
*/
#define GST_TYPE_GHOST_PAD (_gst_ghost_pad_type)
#define GST_GHOST_PAD_CAST(obj) ((GstGhostPad*)(obj))
#define GST_GHOST_PAD_CLASS_CAST(klass) ((GstGhostPadClass*)(klass))
#define GST_IS_GHOST_PAD(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_GHOST_PAD))
#define GST_IS_GHOST_PAD_FAST(obj) (G_OBJECT_TYPE(obj) == GST_TYPE_GHOST_PAD)
#define GST_IS_GHOST_PAD_CLASS(obj) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_GHOST_PAD))
#ifdef GST_TYPE_PARANOID
# define GST_GHOST_PAD(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_GHOST_PAD, GstGhostPad))
# define GST_GHOST_PAD_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_GHOST_PAD, GstGhostPadClass))
#else
# define GST_GHOST_PAD GST_GHOST_PAD_CAST
# define GST_GHOST_PAD_CLASS GST_GHOST_PAD_CLASS_CAST
#endif
/*typedef struct _GstPad GstPad; */
/*typedef struct _GstPadClass GstPadClass;*/
typedef struct _GstRealPad GstRealPad;
typedef struct _GstRealPadClass GstRealPadClass;
typedef struct _GstGhostPad GstGhostPad;
typedef struct _GstGhostPadClass GstGhostPadClass;
/*typedef struct _GstPadTemplate GstPadTemplate;*/
/*typedef struct _GstPadTemplateClass GstPadTemplateClass;*/
typedef enum {
GST_PAD_CONNECT_REFUSED = -1,
GST_PAD_CONNECT_DELAYED = 0,
GST_PAD_CONNECT_OK = 1,
GST_PAD_CONNECT_DONE = 2
} GstPadConnectReturn;
typedef enum {
GST_PAD_QUERY_NONE = 0,
GST_PAD_QUERY_TOTAL,
GST_PAD_QUERY_POSITION,
GST_PAD_QUERY_LATENCY,
GST_PAD_QUERY_JITTER,
GST_PAD_QUERY_START,
GST_PAD_QUERY_SEGMENT_END,
GST_PAD_QUERY_RATE
} GstPadQueryType;
#define GST_PAD_QUERY_TYPE_FUNCTION(functionname, a...) \
static const GstPadQueryType* \
functionname (GstPad *pad) \
{ \
static const GstPadQueryType types[] = { \
a, \
0 \
}; \
return types; \
}
/* this defines the functions used to chain buffers
* pad is the sink pad (so the same chain function can be used for N pads)
* buf is the buffer being passed */
typedef void (*GstPadChainFunction) (GstPad *pad,GstBuffer *buf);
typedef GstBuffer* (*GstPadGetFunction) (GstPad *pad);
typedef gboolean (*GstPadEventFunction) (GstPad *pad, GstEvent *event);
typedef gboolean (*GstPadConvertFunction) (GstPad *pad,
GstFormat src_format, gint64 src_value,
GstFormat *dest_format, gint64 *dest_value);
typedef gboolean (*GstPadQueryFunction) (GstPad *pad, GstPadQueryType type,
GstFormat *format, gint64 *value);
typedef GList* (*GstPadIntConnFunction) (GstPad *pad);
typedef const GstFormat* (*GstPadFormatsFunction) (GstPad *pad);
typedef const GstEventMask* (*GstPadEventMaskFunction) (GstPad *pad);
typedef const GstPadQueryType* (*GstPadQueryTypeFunction) (GstPad *pad);
typedef GstPadConnectReturn (*GstPadConnectFunction) (GstPad *pad, GstCaps *caps);
typedef GstCaps* (*GstPadGetCapsFunction) (GstPad *pad, GstCaps *caps);
typedef GstBufferPool* (*GstPadBufferPoolFunction) (GstPad *pad);
typedef gboolean (*GstPadDispatcherFunction) (GstPad *pad, gpointer data);
typedef enum {
GST_PAD_UNKNOWN,
GST_PAD_SRC,
GST_PAD_SINK
} GstPadDirection;
typedef enum {
GST_PAD_DISABLED = GST_OBJECT_FLAG_LAST,
GST_PAD_EOS,
GST_PAD_FLAG_LAST = GST_OBJECT_FLAG_LAST + 4
} GstPadFlags;
struct _GstPad {
GstObject object;
gpointer element_private;
GstPadTemplate *padtemplate; /* the template for this pad */
};
struct _GstPadClass {
GstObjectClass parent_class;
};
struct _GstRealPad {
GstPad pad;
/* the pad capabilities */
GstCaps *caps;
GstCaps *filter;
GstCaps *appfilter;
GstPadGetCapsFunction getcapsfunc;
GstPadDirection direction;
GstPadConnectFunction connectfunc;
GstRealPad *peer;
gpointer sched_private;
/* data transport functions */
GstPadChainFunction chainfunc;
GstPadChainFunction chainhandler;
GstPadGetFunction getfunc;
GstPadGetFunction gethandler;
GstPadEventFunction eventfunc;
GstPadEventFunction eventhandler;
GstPadEventMaskFunction eventmaskfunc;
GList *ghostpads;
/* query/convert/formats functions */
GstPadConvertFunction convertfunc;
GstPadQueryFunction queryfunc;
GstPadFormatsFunction formatsfunc;
GstPadQueryTypeFunction querytypefunc;
GstPadIntConnFunction intconnfunc;
GstPadBufferPoolFunction bufferpoolfunc;
};
struct _GstRealPadClass {
GstPadClass parent_class;
/* signal callbacks */
void (*set_active) (GstPad *pad, gboolean active);
void (*caps_changed) (GstPad *pad, GstCaps *newcaps);
void (*caps_nego_failed) (GstPad *pad);
void (*connected) (GstPad *pad, GstPad *peer);
void (*disconnected) (GstPad *pad, GstPad *peer);
void (*event_received) (GstPad *pad, GstEvent *event);
void (*eos) (GstPad *pad);
};
struct _GstGhostPad {
GstPad pad;
GstRealPad *realpad;
};
struct _GstGhostPadClass {
GstPadClass parent_class;
};
/***** helper macros *****/
/* GstPad */
#define GST_PAD_NAME(pad) (GST_OBJECT_NAME(pad))
#define GST_PAD_PARENT(pad) ((GstElement *)(GST_OBJECT_PARENT(pad)))
#define GST_PAD_ELEMENT_PRIVATE(pad) (((GstPad *)(pad))->element_private)
#define GST_PAD_PAD_TEMPLATE(pad) (((GstPad *)(pad))->padtemplate)
/* GstRealPad */
#define GST_RPAD_DIRECTION(pad) (((GstRealPad *)(pad))->direction)
#define GST_RPAD_CAPS(pad) (((GstRealPad *)(pad))->caps)
#define GST_RPAD_FILTER(pad) (((GstRealPad *)(pad))->filter)
#define GST_RPAD_APPFILTER(pad) (((GstRealPad *)(pad))->appfilter)
#define GST_RPAD_PEER(pad) (((GstRealPad *)(pad))->peer)
#define GST_RPAD_CHAINFUNC(pad) (((GstRealPad *)(pad))->chainfunc)
#define GST_RPAD_CHAINHANDLER(pad) (((GstRealPad *)(pad))->chainhandler)
#define GST_RPAD_GETFUNC(pad) (((GstRealPad *)(pad))->getfunc)
#define GST_RPAD_GETHANDLER(pad) (((GstRealPad *)(pad))->gethandler)
#define GST_RPAD_EVENTFUNC(pad) (((GstRealPad *)(pad))->eventfunc)
#define GST_RPAD_EVENTHANDLER(pad) (((GstRealPad *)(pad))->eventhandler)
#define GST_RPAD_CONVERTFUNC(pad) (((GstRealPad *)(pad))->convertfunc)
#define GST_RPAD_QUERYFUNC(pad) (((GstRealPad *)(pad))->queryfunc)
#define GST_RPAD_INTCONNFUNC(pad) (((GstRealPad *)(pad))->intconnfunc)
#define GST_RPAD_FORMATSFUNC(pad) (((GstRealPad *)(pad))->formatsfunc)
#define GST_RPAD_QUERYTYPEFUNC(pad) (((GstRealPad *)(pad))->querytypefunc)
#define GST_RPAD_EVENTMASKFUNC(pad) (((GstRealPad *)(pad))->eventmaskfunc)
#define GST_RPAD_EVENT_MASKS(pad) (((GstRealPad *)(pad))->event_masks)
#define GST_RPAD_QUERY_TYPES(pad) (((GstRealPad *)(pad))->query_types)
#define GST_RPAD_CONNECTFUNC(pad) (((GstRealPad *)(pad))->connectfunc)
#define GST_RPAD_GETCAPSFUNC(pad) (((GstRealPad *)(pad))->getcapsfunc)
#define GST_RPAD_BUFFERPOOLFUNC(pad) (((GstRealPad *)(pad))->bufferpoolfunc)
/* GstGhostPad */
#define GST_GPAD_REALPAD(pad) (((GstGhostPad *)(pad))->realpad)
/* Generic */
#define GST_PAD_REALIZE(pad) (GST_IS_REAL_PAD(pad) ? ((GstRealPad *)(pad)) : GST_GPAD_REALPAD(pad))
#define GST_PAD_DIRECTION(pad) GST_RPAD_DIRECTION(GST_PAD_REALIZE(pad))
#define GST_PAD_CAPS(pad) GST_RPAD_CAPS(GST_PAD_REALIZE(pad))
#define GST_PAD_PEER(pad) GST_PAD_CAST(GST_RPAD_PEER(GST_PAD_REALIZE(pad)))
/* Some check functions (unused?) */
#define GST_PAD_IS_CONNECTED(pad) (GST_PAD_PEER(pad) != NULL)
#define GST_PAD_IS_ACTIVE(pad) (!GST_FLAG_IS_SET(pad, GST_PAD_DISABLED))
#define GST_PAD_IS_USABLE(pad) (GST_PAD_IS_CONNECTED (pad) && \
GST_PAD_IS_ACTIVE(pad) && GST_PAD_IS_ACTIVE(GST_PAD_PEER (pad)))
#define GST_PAD_CAN_PULL(pad) (GST_IS_REAL_PAD(pad) && GST_REAL_PAD(pad)->gethandler != NULL)
#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)
/***** PadTemplate *****/
#define GST_TYPE_PAD_TEMPLATE (gst_pad_template_get_type ())
#define GST_PAD_TEMPLATE(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_PAD_TEMPLATE,GstPadTemplate))
#define GST_PAD_TEMPLATE_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_PAD_TEMPLATE,GstPadTemplateClass))
#define GST_IS_PAD_TEMPLATE(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_PAD_TEMPLATE))
#define GST_IS_PAD_TEMPLATE_CLASS(obj) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_PAD_TEMPLATE))
typedef enum {
GST_PAD_ALWAYS,
GST_PAD_SOMETIMES,
GST_PAD_REQUEST
} GstPadPresence;
#define GST_PAD_TEMPLATE_NAME_TEMPLATE(templ) (((GstPadTemplate *)(templ))->name_template)
#define GST_PAD_TEMPLATE_DIRECTION(templ) (((GstPadTemplate *)(templ))->direction)
#define GST_PAD_TEMPLATE_PRESENCE(templ) (((GstPadTemplate *)(templ))->presence)
#define GST_PAD_TEMPLATE_CAPS(templ) (((GstPadTemplate *)(templ))->caps)
#define GST_PAD_TEMPLATE_FIXED(templ) (((GstPadTemplate *)(templ))->fixed)
#define GST_PAD_TEMPLATE_IS_FIXED(templ) (GST_PAD_TEMPLATE_FIXED(templ) == TRUE)
struct _GstPadTemplate {
GstObject object;
gchar *name_template;
GstPadDirection direction;
GstPadPresence presence;
GstCaps *caps;
gboolean fixed;
};
struct _GstPadTemplateClass {
GstObjectClass parent_class;
/* signal callbacks */
void (*pad_created) (GstPadTemplate *templ, GstPad *pad);
};
/* CR1: the space after 'a' is necessary because of preprocessing in gcc */
#define GST_PAD_TEMPLATE_NEW(padname, dir, pres, a...) \
gst_pad_template_new ( \
padname, \
dir, \
pres, \
a , \
NULL)
#define GST_PAD_TEMPLATE_FACTORY(name, padname, dir, pres, a...) \
static GstPadTemplate* \
name (void) \
{ \
static GstPadTemplate *templ = NULL; \
if (!templ) { \
templ = GST_PAD_TEMPLATE_NEW ( \
padname, \
dir, \
pres, \
a ); \
} \
return templ; \
}
#define GST_PAD_TEMPLATE_GET(fact) (fact)()
GType gst_pad_get_type (void);
GType gst_real_pad_get_type (void);
GType gst_ghost_pad_get_type (void);
/* creating pads */
GstPad* gst_pad_new (const gchar *name, GstPadDirection direction);
#define gst_pad_destroy(pad) gst_object_destroy (GST_OBJECT (pad))
GstPad* gst_pad_new_from_template (GstPadTemplate *templ, const gchar *name);
GstPad* gst_pad_custom_new (GType type, const gchar *name, GstPadDirection direction);
GstPad* gst_pad_custom_new_from_template (GType type, GstPadTemplate *templ, const gchar *name);
void gst_pad_set_name (GstPad *pad, const gchar *name);
const gchar* gst_pad_get_name (GstPad *pad);
GstPadDirection gst_pad_get_direction (GstPad *pad);
void gst_pad_set_active (GstPad *pad, gboolean active);
gboolean gst_pad_is_active (GstPad *pad);
void gst_pad_set_element_private (GstPad *pad, gpointer priv);
gpointer gst_pad_get_element_private (GstPad *pad);
void gst_pad_set_parent (GstPad *pad, GstElement *parent);
GstElement* gst_pad_get_parent (GstPad *pad);
GstElement* gst_pad_get_real_parent (GstPad *pad);
GstScheduler* gst_pad_get_scheduler (GstPad *pad);
void gst_pad_add_ghost_pad (GstPad *pad, GstPad *ghostpad);
void gst_pad_remove_ghost_pad (GstPad *pad, GstPad *ghostpad);
GList* gst_pad_get_ghost_pad_list (GstPad *pad);
GstPadTemplate* gst_pad_get_pad_template (GstPad *pad);
void gst_pad_set_bufferpool_function (GstPad *pad, GstPadBufferPoolFunction bufpool);
GstBufferPool* gst_pad_get_bufferpool (GstPad *pad);
/* data passing setup functions */
void gst_pad_set_chain_function (GstPad *pad, GstPadChainFunction chain);
void gst_pad_set_get_function (GstPad *pad, GstPadGetFunction get);
void gst_pad_set_event_function (GstPad *pad, GstPadEventFunction event);
void gst_pad_set_event_mask_function (GstPad *pad, GstPadEventMaskFunction mask_func);
const GstEventMask* gst_pad_get_event_masks (GstPad *pad);
const GstEventMask* gst_pad_get_event_masks_default (GstPad *pad);
gboolean gst_pad_handles_event (GstPad *pad, GstEventMask *mask);
/* pad connections */
void gst_pad_set_connect_function (GstPad *pad, GstPadConnectFunction connect);
gboolean gst_pad_can_connect (GstPad *srcpad, GstPad *sinkpad);
gboolean gst_pad_can_connect_filtered (GstPad *srcpad, GstPad *sinkpad, GstCaps *filtercaps);
gboolean gst_pad_connect (GstPad *srcpad, GstPad *sinkpad);
gboolean gst_pad_connect_filtered (GstPad *srcpad, GstPad *sinkpad, GstCaps *filtercaps);
void gst_pad_disconnect (GstPad *srcpad, GstPad *sinkpad);
GstPad* gst_pad_get_peer (GstPad *pad);
/* capsnego functions */
GstCaps* gst_pad_get_caps (GstPad *pad);
GstCaps* gst_pad_get_pad_template_caps (GstPad *pad);
GstPadConnectReturn gst_pad_try_set_caps (GstPad *pad, GstCaps *caps);
gboolean gst_pad_check_compatibility (GstPad *srcpad, GstPad *sinkpad);
void gst_pad_set_getcaps_function (GstPad *pad, GstPadGetCapsFunction getcaps);
GstPadConnectReturn gst_pad_proxy_connect (GstPad *pad, GstCaps *caps);
gboolean gst_pad_reconnect_filtered (GstPad *srcpad, GstPad *sinkpad, GstCaps *filtercaps);
gboolean gst_pad_perform_negotiate (GstPad *srcpad, GstPad *sinkpad);
gboolean gst_pad_try_reconnect_filtered (GstPad *srcpad, GstPad *sinkpad, GstCaps *filtercaps);
GstCaps* gst_pad_get_allowed_caps (GstPad *pad);
gboolean gst_pad_recalc_allowed_caps (GstPad *pad);
/* data passing functions */
void gst_pad_push (GstPad *pad, GstBuffer *buf);
GstBuffer* gst_pad_pull (GstPad *pad);
gboolean gst_pad_send_event (GstPad *pad, GstEvent *event);
gboolean gst_pad_event_default (GstPad *pad, GstEvent *event);
GstPad* gst_pad_select (GList *padlist);
GstPad* gst_pad_selectv (GstPad *pad, ...);
/* convert/query/format functions */
void gst_pad_set_formats_function (GstPad *pad, GstPadFormatsFunction format);
gboolean gst_pad_handles_format (GstPad *pad, GstFormat format);
const GstFormat* gst_pad_get_formats (GstPad *pad);
const GstFormat* gst_pad_get_formats_default (GstPad *pad);
void gst_pad_set_convert_function (GstPad *pad, GstPadConvertFunction convert);
gboolean gst_pad_convert (GstPad *pad,
GstFormat src_format, gint64 src_value,
GstFormat *dest_format, gint64 *dest_value);
gboolean gst_pad_convert_default (GstPad *pad,
GstFormat src_format, gint64 src_value,
GstFormat *dest_format, gint64 *dest_value);
void gst_pad_set_query_function (GstPad *pad, GstPadQueryFunction query);
void gst_pad_set_query_type_function (GstPad *pad, GstPadQueryTypeFunction type_function);
const GstPadQueryType* gst_pad_get_query_types (GstPad *pad);
const GstPadQueryType* gst_pad_get_query_types_default (GstPad *pad);
gboolean gst_pad_query (GstPad *pad, GstPadQueryType type,
GstFormat *format, gint64 *value);
gboolean gst_pad_query_default (GstPad *pad, GstPadQueryType type,
GstFormat *format, gint64 *value);
void gst_pad_set_internal_connection_function(GstPad *pad, GstPadIntConnFunction intconn);
GList* gst_pad_get_internal_connections (GstPad *pad);
GList* gst_pad_get_internal_connections_default (GstPad *pad);
/* misc helper functions */
gboolean gst_pad_dispatcher (GstPad *pad, GstPadDispatcherFunction dispatch,
gpointer data);
#ifndef GST_DISABLE_LOADSAVE
void gst_pad_load_and_connect (xmlNodePtr self, GstObject *parent);
#endif
/* ghostpads */
GstPad* gst_ghost_pad_new (const gchar *name, GstPad *pad);
/* templates and factories */
GType gst_pad_template_get_type (void);
GstPadTemplate* gst_pad_template_new (const gchar *name_template,
GstPadDirection direction, GstPadPresence presence,
GstCaps *caps, ...);
GstCaps* gst_pad_template_get_caps (GstPadTemplate *templ);
GstCaps* gst_pad_template_get_caps_by_name (GstPadTemplate *templ, const gchar *name);
xmlNodePtr gst_ghost_pad_save_thyself (GstPad *pad,
xmlNodePtr parent);
G_END_DECLS
#endif /* __GST_PAD_H__ */