FFmpeg
buffer_internal.h
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg 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  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #ifndef AVUTIL_BUFFER_INTERNAL_H
20 #define AVUTIL_BUFFER_INTERNAL_H
21 
22 #include <stdatomic.h>
23 #include <stdint.h>
24 
25 #include "buffer.h"
26 #include "thread.h"
27 
28 /**
29  * The buffer is always treated as read-only.
30  */
31 #define BUFFER_FLAG_READONLY (1 << 0)
32 /**
33  * The buffer was av_realloc()ed, so it is reallocatable.
34  */
35 #define BUFFER_FLAG_REALLOCATABLE (1 << 1)
36 
37 struct AVBuffer {
38  uint8_t *data; /**< data described by this buffer */
39  int size; /**< size of data in bytes */
40 
41  /**
42  * number of existing AVBufferRef instances referring to this buffer
43  */
45 
46  /**
47  * a callback for freeing the data
48  */
49  void (*free)(void *opaque, uint8_t *data);
50 
51  /**
52  * an opaque pointer, to be used by the freeing callback
53  */
54  void *opaque;
55 
56  /**
57  * A combination of BUFFER_FLAG_*
58  */
59  int flags;
60 };
61 
62 typedef struct BufferPoolEntry {
64 
65  /*
66  * Backups of the original opaque/free of the AVBuffer corresponding to
67  * data. They will be used to free the buffer when the pool is freed.
68  */
69  void *opaque;
70  void (*free)(void *opaque, uint8_t *data);
71 
75 
76 struct AVBufferPool {
79 
80  /*
81  * This is used to track when the pool is to be freed.
82  * The pointer to the pool itself held by the caller is considered to
83  * be one reference. Each buffer requested by the caller increases refcount
84  * by one, returning the buffer to the pool decreases it by one.
85  * refcount reaches zero when the buffer has been uninited AND all the
86  * buffers have been released, then it's safe to free the pool and all
87  * the buffers in it.
88  */
90 
91  int size;
92  void *opaque;
93  AVBufferRef* (*alloc)(int size);
94  AVBufferRef* (*alloc2)(void *opaque, int size);
95  void (*pool_free)(void *opaque);
96 };
97 
98 #endif /* AVUTIL_BUFFER_INTERNAL_H */
atomic_uint refcount
struct BufferPoolEntry * next
uint8_t * data
data described by this buffer
uint8_t
atomic_uint refcount
number of existing AVBufferRef instances referring to this buffer
The buffer pool.
#define AVMutex
Definition: thread.h:151
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
int flags
A combination of BUFFER_FLAG_*.
void(* free)(void *opaque, uint8_t *data)
a callback for freeing the data
A reference counted buffer type.
intptr_t atomic_uint
Definition: stdatomic.h:56
refcounted data buffer API
void * opaque
an opaque pointer, to be used by the freeing callback
A reference to a data buffer.
Definition: buffer.h:81
AVBufferPool * pool
int size
size of data in bytes
BufferPoolEntry * pool