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1 /* GStreamer Apple Core Video memory
2  * Copyright (C) 2015 Ilya Konstantinov
3  *
4  * This library is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Library General Public
6  * License as published by the Free Software Foundation; either
7  * version 2 of the License, or (at your option) any later version.
8  *
9  * This library is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * Library General Public License for more details.
13  *
14  * You should have received a copy of the GNU Library General Public
15  * License along with this library; if not, write to the
16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17  * Boston, MA 02111-1307, USA.
18  */
19 
20 #ifndef __GST_APPLE_CORE_VIDEO_MEMORY_H__
21 #define __GST_APPLE_CORE_VIDEO_MEMORY_H__
22 
23 #include <gst/gst.h>
24 
25 #include "CoreVideo/CoreVideo.h"
26 
27 G_BEGIN_DECLS
28 
29 /**
30  * GstAppleCoreVideoLockState:
31  *
32  * Specifies whether the backing CVPixelBuffer is locked for read-only
33  * or read-write.
34  *
35  * Locking for reading only improves performance by preventing
36  * Core Video from invalidating existing caches of the buffer’s contents.
37  */
38 typedef enum
39 {
40   GST_APPLE_CORE_VIDEO_MEMORY_UNLOCKED,
41   GST_APPLE_CORE_VIDEO_MEMORY_LOCKED_READONLY,
42   GST_APPLE_CORE_VIDEO_MEMORY_LOCKED_READ_WRITE
43 } GstAppleCoreVideoLockState;
44 
45 /**
46  * GstAppleCoreVideoPixelBuffer:
47  *
48  * This structure wraps CVPixelBuffer, managing its lock states and reference count.
49  * It will be referenced by one or more #GstAppleCoreVideoMemory.
50  */
51 typedef struct
52 {
53   guint refcount;
54   GMutex mutex;
55   CVPixelBufferRef buf;
56   /* Allows mem_map to refuse Read-Write locking a buffer that was previously
57    * locked for Read-Only. */
58   GstAppleCoreVideoLockState lock_state;
59   /* Counts the number of times the buffer was locked.
60    * Only the first lock affects whether it's just for reading
61    * or for reading and writing, as reflected in @lock_state. */
62   guint lock_count;
63 } GstAppleCoreVideoPixelBuffer;
64 
65 /**
66  * GstAppleCoreVideoMemory:
67  *
68  * Represents a video plane or an entire (non-planar) video image,
69  * backed by a CVPixelBuffer.
70  *
71  * This structure shares a #GstAppleCoreVideoPixelBuffer instance
72  * with other instances.
73  */
74 typedef struct
75 {
76   GstMemory mem;
77 
78   GstAppleCoreVideoPixelBuffer *gpixbuf;
79   size_t plane;
80 } GstAppleCoreVideoMemory;
81 
82 void
83 gst_apple_core_video_memory_init (void);
84 
85 GstAppleCoreVideoPixelBuffer *
86 gst_apple_core_video_pixel_buffer_new (CVPixelBufferRef pixbuf);
87 
88 GstAppleCoreVideoPixelBuffer *
89 gst_apple_core_video_pixel_buffer_ref (GstAppleCoreVideoPixelBuffer * shared);
90 
91 void
92 gst_apple_core_video_pixel_buffer_unref (GstAppleCoreVideoPixelBuffer * shared);
93 
94 gboolean
95 gst_is_apple_core_video_memory (GstMemory * mem);
96 
97 GstAppleCoreVideoMemory *
98 gst_apple_core_video_memory_new_wrapped (GstAppleCoreVideoPixelBuffer * shared, gsize plane, gsize size);
99 
100 G_END_DECLS
101 
102 #endif /* __GST_APPLE_CORE_VIDEO_MEMORY_H__ */
103