1 /*  GStreamer video sink base class
2  *  Copyright (C) <2003> Julien Moutte <julien@moutte.net>
3  *  Copyright (C) <2009> Tim-Philipp Müller <tim centricular net>
4  *
5  * This library is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Library General Public
7  * License as published by the Free Software Foundation; either
8  * version 2 of the License, or (at your option) any later version.
9  *
10  * This library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Library General Public License for more details.
14  *
15  * You should have received a copy of the GNU Library General Public
16  * License along with this library; if not, write to the
17  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
18  * Boston, MA 02110-1301, USA.
19  */
20 
21 /* FIXME 0.11: turn this into a proper base class */
22 
23 #ifndef __GST_VIDEO_SINK_H__
24 #define __GST_VIDEO_SINK_H__
25 
26 #include <gst/gst.h>
27 #include <gst/base/gstbasesink.h>
28 #include <gst/video/video-prelude.h>
29 
30 G_BEGIN_DECLS
31 
32 #define GST_TYPE_VIDEO_SINK (gst_video_sink_get_type())
33 #define GST_VIDEO_SINK(obj) \
34   (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_VIDEO_SINK, GstVideoSink))
35 #define GST_VIDEO_SINK_CLASS(klass) \
36   (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_VIDEO_SINK, GstVideoSinkClass))
37 #define GST_IS_VIDEO_SINK(obj) \
38   (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_VIDEO_SINK))
39 #define GST_IS_VIDEO_SINK_CLASS(klass) \
40   (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_VIDEO_SINK))
41 #define GST_VIDEO_SINK_GET_CLASS(klass) \
42   (G_TYPE_INSTANCE_GET_CLASS ((klass), GST_TYPE_VIDEO_SINK, GstVideoSinkClass))
43 
44 /**
45  * GST_VIDEO_SINK_CAST:
46  * @obj: a #GstVideoSink or derived object
47  *
48  * Cast @obj to a #GstVideoSink without runtime type check.
49  */
50 #define GST_VIDEO_SINK_CAST(obj)  ((GstVideoSink *) (obj))
51 
52 /**
53  * GST_VIDEO_SINK_PAD:
54  * @obj: a #GstVideoSink
55  *
56  * Get the sink #GstPad of @obj.
57  */
58 #define GST_VIDEO_SINK_PAD(obj) GST_BASE_SINK_PAD(obj)
59 
60 #define GST_VIDEO_SINK_WIDTH(obj) (GST_VIDEO_SINK_CAST (obj)->width)
61 #define GST_VIDEO_SINK_HEIGHT(obj) (GST_VIDEO_SINK_CAST (obj)->height)
62 
63 typedef struct _GstVideoSink GstVideoSink;
64 typedef struct _GstVideoSinkClass GstVideoSinkClass;
65 typedef struct _GstVideoRectangle GstVideoRectangle;
66 typedef struct _GstVideoSinkPrivate GstVideoSinkPrivate;
67 
68 /**
69  * GstVideoRectangle:
70  * @x: X coordinate of rectangle's top-left point
71  * @y: Y coordinate of rectangle's top-left point
72  * @w: width of the rectangle
73  * @h: height of the rectangle
74  *
75  * Helper structure representing a rectangular area.
76  */
77 struct _GstVideoRectangle {
78   gint x;
79   gint y;
80   gint w;
81   gint h;
82 };
83 
84 /**
85  * GstVideoSink:
86  * @height: video height (derived class needs to set this)
87  * @width: video width (derived class needs to set this)
88  *
89  * The video sink instance structure. Derived video sinks should set the
90  * @height and @width members.
91  */
92 struct _GstVideoSink {
93   GstBaseSink element;    /* FIXME 0.11: this should not be called 'element' */
94 
95   /*< public >*/
96   gint width, height;
97 
98   /*< private >*/
99   GstVideoSinkPrivate *priv;
100 
101   gpointer _gst_reserved[GST_PADDING];
102 };
103 
104 /**
105  * GstVideoSinkClass:
106  * @parent_class: the parent class structure
107  * @show_frame: render a video frame. Maps to #GstBaseSinkClass.render() and
108  *     #GstBaseSinkClass.preroll() vfuncs. Rendering during preroll will be
109  *     suppressed if the #GstVideoSink:show-preroll-frame property is set to
110  *     %FALSE.
111  *
112  * The video sink class structure. Derived classes should override the
113  * @show_frame virtual function.
114  */
115 struct _GstVideoSinkClass {
116   GstBaseSinkClass parent_class;
117 
118   GstFlowReturn  (*show_frame) (GstVideoSink *video_sink, GstBuffer *buf);
119 
120   /*< private >*/
121   gpointer _gst_reserved[GST_PADDING];
122 };
123 
124 GST_VIDEO_API
125 GType gst_video_sink_get_type (void);
126 
127 GST_VIDEO_API
128 void gst_video_sink_center_rect (GstVideoRectangle src, GstVideoRectangle dst,
129                                  GstVideoRectangle *result, gboolean scaling);
130 
131 #ifdef G_DEFINE_AUTOPTR_CLEANUP_FUNC
132 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstVideoSink, gst_object_unref)
133 #endif
134 
135 G_END_DECLS
136 
137 #endif  /* __GST_VIDEO_SINK_H__ */
138