2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
5 * gstelement.h: Header for GstElement
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
24 #ifndef __GST_ELEMENT_H__
25 #define __GST_ELEMENT_H__
27 #include <gst/gstconfig.h>
29 #include <gst/gsttypes.h>
30 #include <gst/gstobject.h>
31 #include <gst/gstpad.h>
32 #include <gst/cothreads.h>
33 #include <gst/gstpluginfeature.h>
37 #endif /* __cplusplus */
39 #define GST_NUM_STATES 4
42 /* NOTE: this probably should be done with an #ifdef to decide
43 * whether to safe-cast or to just do the non-checking cast.
45 #define GST_STATE(obj) (GST_ELEMENT(obj)->current_state)
46 #define GST_STATE_PENDING(obj) (GST_ELEMENT(obj)->pending_state)
48 /* Note: using 8 bit shift mostly "just because", it leaves us enough room to grow <g> */
49 #define GST_STATE_TRANSITION(obj) ((GST_STATE(obj)<<8) | GST_STATE_PENDING(obj))
50 #define GST_STATE_NULL_TO_READY ((GST_STATE_NULL<<8) | GST_STATE_READY)
51 #define GST_STATE_READY_TO_PAUSED ((GST_STATE_READY<<8) | GST_STATE_PAUSED)
52 #define GST_STATE_PAUSED_TO_PLAYING ((GST_STATE_PAUSED<<8) | GST_STATE_PLAYING)
53 #define GST_STATE_PLAYING_TO_PAUSED ((GST_STATE_PLAYING<<8) | GST_STATE_PAUSED)
54 #define GST_STATE_PAUSED_TO_READY ((GST_STATE_PAUSED<<8) | GST_STATE_READY)
55 #define GST_STATE_READY_TO_NULL ((GST_STATE_READY<<8) | GST_STATE_NULL)
57 extern GType _gst_element_type;
59 #define GST_TYPE_ELEMENT (_gst_element_type)
61 #define GST_ELEMENT_CAST(obj) ((GstElement*)(obj))
62 #define GST_ELEMENT_CLASS_CAST(klass) ((GstElementClass*)(klass))
63 #define GST_IS_ELEMENT(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_ELEMENT))
64 #define GST_IS_ELEMENT_CLASS(obj) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_ELEMENT))
66 #ifdef GST_TYPE_PARANOID
67 # define GST_ELEMENT(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_ELEMENT, GstElement))
68 # define GST_ELEMENT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_ELEMENT, GstElementClass))
70 # define GST_ELEMENT GST_ELEMENT_CAST
71 # define GST_ELEMENT_CLASS GST_ELEMENT_CLASS_CAST
75 /* element is complex (for some def.) and generally require a cothread */
76 GST_ELEMENT_COMPLEX = GST_OBJECT_FLAG_LAST,
77 /* input and output pads aren't directly coupled to each other
78 examples: queues, multi-output async readers, etc. */
79 GST_ELEMENT_DECOUPLED,
80 /* this element should be placed in a thread if at all possible */
81 GST_ELEMENT_THREAD_SUGGESTED,
82 /* this element is incable of seeking (FIXME: does this apply to filters?) */
85 /* this element, for some reason, has a loop function that performs
86 * an infinite loop without calls to gst_element_yield () */
87 GST_ELEMENT_INFINITE_LOOP,
89 /* private flags that can be used by the scheduler */
90 GST_ELEMENT_SCHEDULER_PRIVATE1,
91 GST_ELEMENT_SCHEDULER_PRIVATE2,
93 /* there is a new loopfunction ready for placement */
94 GST_ELEMENT_NEW_LOOPFUNC,
96 /* if this element can handle events */
97 GST_ELEMENT_EVENT_AWARE,
99 /* use some padding for future expansion */
100 GST_ELEMENT_FLAG_LAST = GST_OBJECT_FLAG_LAST + 12,
103 #define GST_ELEMENT_IS_THREAD_SUGGESTED(obj) (GST_FLAG_IS_SET(obj,GST_ELEMENT_THREAD_SUGGESTED))
104 #define GST_ELEMENT_IS_EOS(obj) (GST_FLAG_IS_SET(obj,GST_ELEMENT_EOS))
105 #define GST_ELEMENT_IS_EVENT_AWARE(obj) (GST_FLAG_IS_SET(obj,GST_ELEMENT_EVENT_AWARE))
107 #define GST_ELEMENT_NAME(obj) (GST_OBJECT_NAME(obj))
108 #define GST_ELEMENT_PARENT(obj) (GST_OBJECT_PARENT(obj))
109 #define GST_ELEMENT_MANAGER(obj) (((GstElement*)(obj))->manager)
110 #define GST_ELEMENT_SCHED(obj) (((GstElement*)(obj))->sched)
111 #define GST_ELEMENT_PADS(obj) ((obj)->pads)
113 /*typedef struct _GstElement GstElement;*/
114 /*typedef struct _GstElementClass GstElementClass;*/
115 typedef struct _GstElementFactory GstElementFactory;
116 typedef struct _GstElementFactoryClass GstElementFactoryClass;
118 typedef void (*GstElementLoopFunction) (GstElement *element);
123 /* element state and scheduling */
124 guint8 current_state;
125 guint8 pending_state;
127 GstElementLoopFunction loopfunc;
130 gpointer sched_private;
143 struct _GstElementClass {
144 GstObjectClass parent_class;
146 /* the elementfactory that created us */
147 GstElementFactory *elementfactory;
148 /* templates for our pads */
150 gint numpadtemplates;
152 /* signal callbacks */
153 void (*state_change) (GstElement *element, GstElementState old, GstElementState state);
154 void (*new_pad) (GstElement *element, GstPad *pad);
155 void (*pad_removed) (GstElement *element, GstPad *pad);
156 void (*error) (GstElement *element, gchar *error);
157 void (*event) (GstElement *element, GstEvent *event);
158 void (*eos) (GstElement *element);
160 /* local pointers for get/set */
161 void (*set_property) (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec);
162 void (*get_property) (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec);
165 /* change the element state */
166 GstElementStateReturn (*change_state) (GstElement *element);
167 /* request a new pad */
168 GstPad* (*request_new_pad) (GstElement *element, GstPadTemplate *templ, const gchar* name);
169 void (*send_event) (GstElement *element, GstEvent *event);
172 void gst_element_class_add_padtemplate (GstElementClass *klass, GstPadTemplate *templ);
174 GType gst_element_get_type (void);
175 #define gst_element_destroy(element) gst_object_destroy (GST_OBJECT (element))
177 void gst_element_set_loop_function (GstElement *element,
178 GstElementLoopFunction loop);
180 void gst_element_set_name (GstElement *element, const gchar *name);
181 const gchar* gst_element_get_name (GstElement *element);
183 void gst_element_set_parent (GstElement *element, GstObject *parent);
184 GstObject* gst_element_get_parent (GstElement *element);
186 void gst_element_yield (GstElement *element);
187 void gst_element_interrupt (GstElement *element);
188 void gst_element_set_sched (GstElement *element, GstScheduler *sched);
189 GstScheduler* gst_element_get_sched (GstElement *element);
191 void gst_element_add_pad (GstElement *element, GstPad *pad);
192 void gst_element_remove_pad (GstElement *element, GstPad *pad);
193 GstPad* gst_element_get_pad (GstElement *element, const gchar *name);
194 GList* gst_element_get_pad_list (GstElement *element);
195 GList* gst_element_get_padtemplate_list (GstElement *element);
196 GstPadTemplate* gst_element_get_padtemplate_by_name (GstElement *element, const guchar *name);
197 void gst_element_add_ghost_pad (GstElement *element, GstPad *pad, gchar *name);
198 void gst_element_remove_ghost_pad (GstElement *element, GstPad *pad);
200 GstPad* gst_element_request_compatible_pad (GstElement *element, GstPadTemplate *templ);
201 GstPad* gst_element_request_pad_by_name (GstElement *element, const gchar *name);
203 void gst_element_connect (GstElement *src, const gchar *srcpadname,
204 GstElement *dest, const gchar *destpadname);
205 void gst_element_disconnect (GstElement *src, const gchar *srcpadname,
206 GstElement *dest, const gchar *destpadname);
208 void gst_element_signal_eos (GstElement *element);
210 void gst_element_send_event (GstElement *element, GstEvent *event);
213 GstElementState gst_element_get_state (GstElement *element);
214 gint gst_element_set_state (GstElement *element, GstElementState state);
216 void gst_element_wait_state_change (GstElement *element);
218 const gchar* gst_element_statename (GstElementState state);
220 void gst_element_info (GstElement *element, const gchar *info, ...);
221 void gst_element_error (GstElement *element, const gchar *error, ...);
223 GstElementFactory* gst_element_get_factory (GstElement *element);
225 void gst_element_install_std_props (GstElementClass *klass,
226 const char *first_name, ...);
229 #ifndef GST_DISABLE_LOADSAVE
230 /* XML write and read */
231 GstElement* gst_element_restore_thyself (xmlNodePtr self, GstObject *parent);
240 typedef struct _GstElementDetails GstElementDetails;
242 struct _GstElementDetails {
243 gchar *longname; /* long, english name */
244 gchar *klass; /* type of element, as hierarchy */
245 gchar *description; /* insights of one form or another */
246 gchar *version; /* version of the element */
247 gchar *author; /* who wrote this thing? */
248 gchar *copyright; /* copyright details (year, etc.) */
251 #define GST_TYPE_ELEMENTFACTORY (gst_elementfactory_get_type())
252 #define GST_ELEMENTFACTORY(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_ELEMENTFACTORY,\
254 #define GST_ELEMENTFACTORY_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_ELEMENTFACTORY,\
255 GstElementFactoryClass))
256 #define GST_IS_ELEMENTFACTORY(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_ELEMENTFACTORY))
257 #define GST_IS_ELEMENTFACTORY_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_ELEMENTFACTORY))
259 struct _GstElementFactory {
260 GstPluginFeature feature;
262 GType type; /* unique GType of element */
264 guint details_dynamic : 1;
266 GstElementDetails *details; /* pointer to details struct */
269 guint16 numpadtemplates;
272 struct _GstElementFactoryClass {
273 GstPluginFeatureClass parent_class;
276 GType gst_elementfactory_get_type (void);
278 GstElementFactory* gst_elementfactory_new (const gchar *name,GType type,
279 GstElementDetails *details);
281 GstElementFactory* gst_elementfactory_find (const gchar *name);
282 const GList* gst_elementfactory_get_list (void);
284 void gst_elementfactory_add_padtemplate (GstElementFactory *elementfactory,
285 GstPadTemplate *templ);
287 gboolean gst_elementfactory_can_src_caps (GstElementFactory *factory,
289 gboolean gst_elementfactory_can_sink_caps (GstElementFactory *factory,
292 GstElement* gst_elementfactory_create (GstElementFactory *factory,
294 /* FIXME this name is wrong, probably so is the one above it */
295 GstElement* gst_elementfactory_make (const gchar *factoryname, const gchar *name);
299 #endif /* __cplusplus */
302 #endif /* __GST_ELEMENT_H__ */