gstreamer/gst/gstelement.h

/* Gnome-Streamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 *
 * 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_ELEMENT_H__
#define __GST_ELEMENT_H__


#include <gnome-xml/parser.h>
#include <gst/gstlog.h>
#include <gst/gstobject.h>
#include <gst/gstpad.h>
#include <gst/gstbuffer.h>
#include <gst/cothreads.h>


#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */


typedef enum {
  GST_STATE_NONE_PENDING	= -1,
  GST_STATE_NULL	= 0,
  GST_STATE_READY	= 1,
  GST_STATE_PLAYING	= 2,
  GST_STATE_PAUSED	= 3,
} GstElementState;

typedef enum {
  GST_STATE_FAILURE	= 0,
  GST_STATE_SUCCESS	= 1,
  GST_STATE_ASYNC	= 2,
} GstElementStateReturn;

static inline char *_gst_print_statename(int state) {
  switch (state) {
    case -1: return "none pending";break;
    case 0: return "null";break;
    case 1: return "ready";break;
    case 2: return "playing";break;
    case 3: return "paused";break;
    default: return "";
  }
  return "";
}

#define GST_STATE(obj)			(GST_ELEMENT(obj)->current_state)
#define GST_STATE_PENDING(obj)		(GST_ELEMENT(obj)->pending_state)

#define GST_TYPE_ELEMENT \
  (gst_element_get_type())
#define GST_ELEMENT(obj) \
  (GTK_CHECK_CAST((obj),GST_TYPE_ELEMENT,GstElement))
#define GST_ELEMENT_CLASS(klass) \
  (GTK_CHECK_CLASS_CAST((klass),GST_TYPE_ELEMENT,GstElementClass))
#define GST_IS_ELEMENT(obj) \
  (GTK_CHECK_TYPE((obj),GST_TYPE_ELEMENT))
#define GST_IS_ELEMENT_CLASS(klass) \
  (GTK_CHECK_CLASS_TYPE((klass),GST_TYPE_ELEMENT))

typedef enum {
  GST_ELEMENT_MULTI_IN		= (1 << 4),
  GST_ELEMENT_THREAD_SUGGESTED	= (1 << 5),
} GstElementFlags;

#define GST_ELEMENT_IS_MULTI_IN(obj)	(GST_FLAGS(obj) & GST_ELEMENT_MULTI_IN)
#define GST_ELEMENT_IS_THREAD_SUGGESTED(obj)	(GST_FLAGS(obj) & GST_ELEMENT_THREAD_SUGGESTED)


typedef struct _GstElement GstElement;
typedef struct _GstElementClass GstElementClass;
typedef struct _GstElementDetails GstElementDetails;
typedef struct _GstElementFactory GstElementFactory;

typedef void (*GstElementLoopFunction) (GstElement *element);

struct _GstElement {
  GstObject object;

  gchar *name;

  guint8 current_state;
  guint8 pending_state;

  GstElementLoopFunction loopfunc;
  cothread_state *threadstate;

  guint16 numpads;
  GList *pads;

  GstElement *manager;
};

struct _GstElementClass {
  GstObjectClass parent_class;

  /* the elementfactory that created us */
  GstElementFactory *elementfactory;

  /* signal callbacks */
  void (*state_change) (GstElement *element,GstElementState state);
  void (*new_pad) (GstElement *element,GstPad *pad);
  void (*new_ghost_pad) (GstElement *element,GstPad *pad);
  void (*error) (GstElement *element,gchar *error);

  /* events */
//  gboolean (*start) (GstElement *element,GstElementState state);
//  gboolean (*stop) (GstElement *element);

  /* change the element state */
  GstElementStateReturn (*change_state) (GstElement *element);

  /* create or read XML representation of self */
  xmlNodePtr (*save_thyself)(GstElement *element,xmlNodePtr parent);
  void (*restore_thyself)(GstElement *element, xmlNodePtr self, GHashTable *elements);
};

struct _GstElementDetails {
  gchar *longname;              /* long, english name */
  gchar *class;                 /* type of element, kinda */
  gchar *description;           /* insights of one form or another */
  gchar *version;               /* version of the element */
  gchar *author;                /* who wrote this thing? */
  gchar *copyright;             /* copyright details (year, etc.) */
};

struct _GstElementFactory {
  gchar *name;			/* name of element */
  GtkType type;			/* unique GtkType of element */

  GstElementDetails *details;	/* pointer to details struct */

  GList *src_types;
  GList *sink_types;
};

GtkType gst_element_get_type(void);
GstElement *gst_element_new(void);

void gst_element_set_loop_function(GstElement *element,
                                   GstElementLoopFunction loop);

void gst_element_set_name(GstElement *element,gchar *name);
gchar *gst_element_get_name(GstElement *element);

void gst_element_set_manager(GstElement *element,GstElement *manager);
GstElement *gst_element_get_manager(GstElement *element);

void gst_element_add_pad(GstElement *element,GstPad *pad);
void gst_element_add_ghost_pad(GstElement *element,GstPad *pad);
GstPad *gst_element_get_pad(GstElement *element,gchar *name);
GList *gst_element_get_pad_list(GstElement *element);

void gst_element_connect(GstElement *src,gchar *srcpadname,
                         GstElement *dest,gchar *destpadname);

/* called by the app to set the state of the element */
gint gst_element_set_state(GstElement *element,GstElementState state);

void gst_element_error(GstElement *element,gchar *error);

GstElementFactory *gst_element_get_factory(GstElement *element);

#define gst_element_destroy(element) gst_object_destroy(GST_OBJECT(element))

/* XML write and read */
xmlNodePtr gst_element_save_thyself(GstElement *element,xmlNodePtr parent);
GstElement *gst_element_load_thyself(xmlNodePtr parent, GHashTable *elements);

GstElementFactory *gst_elementfactory_new(gchar *name,GtkType type,
                                          GstElementDetails *details);
void gst_elementfactory_register(GstElementFactory *elementfactory);

void gst_elementfactory_add_src(GstElementFactory *elementfactory, guint16 id);
void gst_elementfactory_add_sink(GstElementFactory *elementfactory, guint16 id);

GstElementFactory *gst_elementfactory_find(gchar *name);
GList *gst_elementfactory_get_list();

GstElement *gst_elementfactory_create(GstElementFactory *factory,
                                      gchar *name);
  
// FIXME this name is wrong, probably so is the one above it
GstElement *gst_elementfactory_make(gchar *factoryname,gchar *name);

xmlNodePtr gst_elementfactory_save_thyself(GstElementFactory *factory, xmlNodePtr parent); 
GstElementFactory *gst_elementfactory_load_thyself(xmlNodePtr parent);

int gst_element_loopfunc_wrapper(int argc,char **argv);

#ifdef __cplusplus
}
#endif /* __cplusplus */


#endif /* __GST_ELEMENT_H__ */