0
|
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 /**
|
|
20 * @file
|
|
21 * a very simple circular buffer FIFO implementation
|
|
22 */
|
|
23
|
|
24 #ifndef AVUTIL_FIFO_H
|
|
25 #define AVUTIL_FIFO_H
|
|
26
|
|
27 #include <stdint.h>
|
|
28 #include "avutil.h"
|
|
29 #include "attributes.h"
|
|
30
|
|
31 typedef struct AVFifoBuffer {
|
|
32 uint8_t *buffer;
|
|
33 uint8_t *rptr, *wptr, *end;
|
|
34 uint32_t rndx, wndx;
|
|
35 } AVFifoBuffer;
|
|
36
|
|
37 /**
|
|
38 * Initialize an AVFifoBuffer.
|
|
39 * @param size of FIFO
|
|
40 * @return AVFifoBuffer or NULL in case of memory allocation failure
|
|
41 */
|
|
42 AVFifoBuffer *av_fifo_alloc(unsigned int size);
|
|
43
|
|
44 /**
|
|
45 * Initialize an AVFifoBuffer.
|
|
46 * @param nmemb number of elements
|
|
47 * @param size size of the single element
|
|
48 * @return AVFifoBuffer or NULL in case of memory allocation failure
|
|
49 */
|
|
50 AVFifoBuffer *av_fifo_alloc_array(size_t nmemb, size_t size);
|
|
51
|
|
52 /**
|
|
53 * Free an AVFifoBuffer.
|
|
54 * @param f AVFifoBuffer to free
|
|
55 */
|
|
56 void av_fifo_free(AVFifoBuffer *f);
|
|
57
|
|
58 /**
|
|
59 * Free an AVFifoBuffer and reset pointer to NULL.
|
|
60 * @param f AVFifoBuffer to free
|
|
61 */
|
|
62 void av_fifo_freep(AVFifoBuffer **f);
|
|
63
|
|
64 /**
|
|
65 * Reset the AVFifoBuffer to the state right after av_fifo_alloc, in particular it is emptied.
|
|
66 * @param f AVFifoBuffer to reset
|
|
67 */
|
|
68 void av_fifo_reset(AVFifoBuffer *f);
|
|
69
|
|
70 /**
|
|
71 * Return the amount of data in bytes in the AVFifoBuffer, that is the
|
|
72 * amount of data you can read from it.
|
|
73 * @param f AVFifoBuffer to read from
|
|
74 * @return size
|
|
75 */
|
|
76 int av_fifo_size(FF_CONST_AVUTIL53 AVFifoBuffer *f);
|
|
77
|
|
78 /**
|
|
79 * Return the amount of space in bytes in the AVFifoBuffer, that is the
|
|
80 * amount of data you can write into it.
|
|
81 * @param f AVFifoBuffer to write into
|
|
82 * @return size
|
|
83 */
|
|
84 int av_fifo_space(FF_CONST_AVUTIL53 AVFifoBuffer *f);
|
|
85
|
|
86 /**
|
|
87 * Feed data from an AVFifoBuffer to a user-supplied callback.
|
|
88 * @param f AVFifoBuffer to read from
|
|
89 * @param buf_size number of bytes to read
|
|
90 * @param func generic read function
|
|
91 * @param dest data destination
|
|
92 */
|
|
93 int av_fifo_generic_read(AVFifoBuffer *f, void *dest, int buf_size, void (*func)(void*, void*, int));
|
|
94
|
|
95 /**
|
|
96 * Feed data from a user-supplied callback to an AVFifoBuffer.
|
|
97 * @param f AVFifoBuffer to write to
|
|
98 * @param src data source; non-const since it may be used as a
|
|
99 * modifiable context by the function defined in func
|
|
100 * @param size number of bytes to write
|
|
101 * @param func generic write function; the first parameter is src,
|
|
102 * the second is dest_buf, the third is dest_buf_size.
|
|
103 * func must return the number of bytes written to dest_buf, or <= 0 to
|
|
104 * indicate no more data available to write.
|
|
105 * If func is NULL, src is interpreted as a simple byte array for source data.
|
|
106 * @return the number of bytes written to the FIFO
|
|
107 */
|
|
108 int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int));
|
|
109
|
|
110 /**
|
|
111 * Resize an AVFifoBuffer.
|
|
112 * In case of reallocation failure, the old FIFO is kept unchanged.
|
|
113 *
|
|
114 * @param f AVFifoBuffer to resize
|
|
115 * @param size new AVFifoBuffer size in bytes
|
|
116 * @return <0 for failure, >=0 otherwise
|
|
117 */
|
|
118 int av_fifo_realloc2(AVFifoBuffer *f, unsigned int size);
|
|
119
|
|
120 /**
|
|
121 * Enlarge an AVFifoBuffer.
|
|
122 * In case of reallocation failure, the old FIFO is kept unchanged.
|
|
123 * The new fifo size may be larger than the requested size.
|
|
124 *
|
|
125 * @param f AVFifoBuffer to resize
|
|
126 * @param additional_space the amount of space in bytes to allocate in addition to av_fifo_size()
|
|
127 * @return <0 for failure, >=0 otherwise
|
|
128 */
|
|
129 int av_fifo_grow(AVFifoBuffer *f, unsigned int additional_space);
|
|
130
|
|
131 /**
|
|
132 * Read and discard the specified amount of data from an AVFifoBuffer.
|
|
133 * @param f AVFifoBuffer to read from
|
|
134 * @param size amount of data to read in bytes
|
|
135 */
|
|
136 void av_fifo_drain(AVFifoBuffer *f, int size);
|
|
137
|
|
138 /**
|
|
139 * Return a pointer to the data stored in a FIFO buffer at a certain offset.
|
|
140 * The FIFO buffer is not modified.
|
|
141 *
|
|
142 * @param f AVFifoBuffer to peek at, f must be non-NULL
|
|
143 * @param offs an offset in bytes, its absolute value must be less
|
|
144 * than the used buffer size or the returned pointer will
|
|
145 * point outside to the buffer data.
|
|
146 * The used buffer size can be checked with av_fifo_size().
|
|
147 */
|
|
148 static inline uint8_t *av_fifo_peek2(const AVFifoBuffer *f, int offs)
|
|
149 {
|
|
150 uint8_t *ptr = f->rptr + offs;
|
|
151 if (ptr >= f->end)
|
|
152 ptr = f->buffer + (ptr - f->end);
|
|
153 else if (ptr < f->buffer)
|
|
154 ptr = f->end - (f->buffer - ptr);
|
|
155 return ptr;
|
|
156 }
|
|
157
|
|
158 #endif /* AVUTIL_FIFO_H */
|