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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 <stdint.h>
23 
24 #include "buffer.h"
25 #include "thread.h"
26 
27 /**
28  * The buffer is always treated as read-only.
29  */
30 #define BUFFER_FLAG_READONLY (1 << 0)
31 /**
32  * The buffer was av_realloc()ed, so it is reallocatable.
33  */
34 #define BUFFER_FLAG_REALLOCATABLE (1 << 1)
35 
36 struct AVBuffer {
37  uint8_t *data; /**< data described by this buffer */
38  int size; /**< size of data in bytes */
39 
40  /**
41  * number of existing AVBufferRef instances referring to this buffer
42  */
43  volatile int refcount;
44 
45  /**
46  * a callback for freeing the data
47  */
48  void (*free)(void *opaque, uint8_t *data);
49 
50  /**
51  * an opaque pointer, to be used by the freeing callback
52  */
53  void *opaque;
54 
55  /**
56  * A combination of BUFFER_FLAG_*
57  */
58  int flags;
59 };
60 
61 typedef struct BufferPoolEntry {
63 
64  /*
65  * Backups of the original opaque/free of the AVBuffer corresponding to
66  * data. They will be used to free the buffer when the pool is freed.
67  */
68  void *opaque;
69  void (*free)(void *opaque, uint8_t *data);
70 
74 
75 struct AVBufferPool {
78 
79  /*
80  * This is used to track when the pool is to be freed.
81  * The pointer to the pool itself held by the caller is considered to
82  * be one reference. Each buffer requested by the caller increases refcount
83  * by one, returning the buffer to the pool decreases it by one.
84  * refcount reaches zero when the buffer has been uninited AND all the
85  * buffers have been released, then it's safe to free the pool and all
86  * the buffers in it.
87  */
88  volatile int refcount;
89 
90  volatile int nb_allocated;
91 
92  int size;
93  AVBufferRef* (*alloc)(int size);
94 };
95 
96 #endif /* AVUTIL_BUFFER_INTERNAL_H */
void(* free)(void *opaque, uint8_t *data)
a callback for freeing the data
struct BufferPoolEntry * next
volatile int refcount
number of existing AVBufferRef instances referring to this buffer
uint8_t * data
data described by this buffer
uint8_t
The buffer pool.
#define AVMutex
Definition: thread.h:50
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
void(* free)(void *opaque, uint8_t *data)
int flags
A combination of BUFFER_FLAG_*.
volatile int nb_allocated
A reference counted buffer type.
refcounted data buffer API
volatile int refcount
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