bytestream.h
Go to the documentation of this file.
1 /*
2  * Bytestream functions
3  * copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@free.fr>
4  * Copyright (c) 2012 Aneesh Dogra (lionaneesh) <lionaneesh@gmail.com>
5  *
6  * This file is part of Libav.
7  *
8  * Libav is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * Libav is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #ifndef AVCODEC_BYTESTREAM_H
24 #define AVCODEC_BYTESTREAM_H
25 
26 #include <stdint.h>
27 #include <string.h>
28 
29 #include "libavutil/common.h"
30 #include "libavutil/intreadwrite.h"
31 
32 typedef struct GetByteContext {
35 
36 typedef struct PutByteContext {
38  int eof;
40 
41 #define DEF(type, name, bytes, read, write) \
42 static av_always_inline type bytestream_get_ ## name(const uint8_t **b) \
43 { \
44  (*b) += bytes; \
45  return read(*b - bytes); \
46 } \
47 static av_always_inline void bytestream_put_ ## name(uint8_t **b, \
48  const type value) \
49 { \
50  write(*b, value); \
51  (*b) += bytes; \
52 } \
53 static av_always_inline void bytestream2_put_ ## name ## u(PutByteContext *p, \
54  const type value) \
55 { \
56  bytestream_put_ ## name(&p->buffer, value); \
57 } \
58 static av_always_inline void bytestream2_put_ ## name(PutByteContext *p, \
59  const type value) \
60 { \
61  if (!p->eof && (p->buffer_end - p->buffer >= bytes)) { \
62  write(p->buffer, value); \
63  p->buffer += bytes; \
64  } else \
65  p->eof = 1; \
66 } \
67 static av_always_inline type bytestream2_get_ ## name ## u(GetByteContext *g) \
68 { \
69  return bytestream_get_ ## name(&g->buffer); \
70 } \
71 static av_always_inline type bytestream2_get_ ## name(GetByteContext *g) \
72 { \
73  if (g->buffer_end - g->buffer < bytes) \
74  return 0; \
75  return bytestream2_get_ ## name ## u(g); \
76 } \
77 static av_always_inline type bytestream2_peek_ ## name(GetByteContext *g) \
78 { \
79  if (g->buffer_end - g->buffer < bytes) \
80  return 0; \
81  return read(g->buffer); \
82 }
83 
84 DEF(uint64_t, le64, 8, AV_RL64, AV_WL64)
85 DEF(unsigned int, le32, 4, AV_RL32, AV_WL32)
86 DEF(unsigned int, le24, 3, AV_RL24, AV_WL24)
87 DEF(unsigned int, le16, 2, AV_RL16, AV_WL16)
88 DEF(uint64_t, be64, 8, AV_RB64, AV_WB64)
89 DEF(unsigned int, be32, 4, AV_RB32, AV_WB32)
90 DEF(unsigned int, be24, 3, AV_RB24, AV_WB24)
91 DEF(unsigned int, be16, 2, AV_RB16, AV_WB16)
92 DEF(unsigned int, byte, 1, AV_RB8 , AV_WB8)
93 
94 #if HAVE_BIGENDIAN
95 # define bytestream2_get_ne16 bytestream2_get_be16
96 # define bytestream2_get_ne24 bytestream2_get_be24
97 # define bytestream2_get_ne32 bytestream2_get_be32
98 # define bytestream2_get_ne64 bytestream2_get_be64
99 # define bytestream2_get_ne16u bytestream2_get_be16u
100 # define bytestream2_get_ne24u bytestream2_get_be24u
101 # define bytestream2_get_ne32u bytestream2_get_be32u
102 # define bytestream2_get_ne64u bytestream2_get_be64u
103 # define bytestream2_put_ne16 bytestream2_put_be16
104 # define bytestream2_put_ne24 bytestream2_put_be24
105 # define bytestream2_put_ne32 bytestream2_put_be32
106 # define bytestream2_put_ne64 bytestream2_put_be64
107 # define bytestream2_peek_ne16 bytestream2_peek_be16
108 # define bytestream2_peek_ne24 bytestream2_peek_be24
109 # define bytestream2_peek_ne32 bytestream2_peek_be32
110 # define bytestream2_peek_ne64 bytestream2_peek_be64
111 #else
112 # define bytestream2_get_ne16 bytestream2_get_le16
113 # define bytestream2_get_ne24 bytestream2_get_le24
114 # define bytestream2_get_ne32 bytestream2_get_le32
115 # define bytestream2_get_ne64 bytestream2_get_le64
116 # define bytestream2_get_ne16u bytestream2_get_le16u
117 # define bytestream2_get_ne24u bytestream2_get_le24u
118 # define bytestream2_get_ne32u bytestream2_get_le32u
119 # define bytestream2_get_ne64u bytestream2_get_le64u
120 # define bytestream2_put_ne16 bytestream2_put_le16
121 # define bytestream2_put_ne24 bytestream2_put_le24
122 # define bytestream2_put_ne32 bytestream2_put_le32
123 # define bytestream2_put_ne64 bytestream2_put_le64
124 # define bytestream2_peek_ne16 bytestream2_peek_le16
125 # define bytestream2_peek_ne24 bytestream2_peek_le24
126 # define bytestream2_peek_ne32 bytestream2_peek_le32
127 # define bytestream2_peek_ne64 bytestream2_peek_le64
128 #endif
129 
131  const uint8_t *buf,
132  int buf_size)
133 {
134  g->buffer = buf;
135  g->buffer_start = buf;
136  g->buffer_end = buf + buf_size;
137 }
138 
140  uint8_t *buf,
141  int buf_size)
142 {
143  p->buffer = buf;
144  p->buffer_start = buf;
145  p->buffer_end = buf + buf_size;
146  p->eof = 0;
147 }
148 
150 {
151  return g->buffer_end - g->buffer;
152 }
153 
155 {
156  return p->buffer_end - p->buffer;
157 }
158 
160  unsigned int size)
161 {
162  g->buffer += FFMIN(g->buffer_end - g->buffer, size);
163 }
164 
166  unsigned int size)
167 {
168  g->buffer += size;
169 }
170 
172  unsigned int size)
173 {
174  int size2;
175  if (p->eof)
176  return;
177  size2 = FFMIN(p->buffer_end - p->buffer, size);
178  if (size2 != size)
179  p->eof = 1;
180  p->buffer += size2;
181 }
182 
184 {
185  return (int)(g->buffer - g->buffer_start);
186 }
187 
189 {
190  return (int)(p->buffer - p->buffer_start);
191 }
192 
194  int offset,
195  int whence)
196 {
197  switch (whence) {
198  case SEEK_CUR:
199  offset = av_clip(offset, -(g->buffer - g->buffer_start),
200  g->buffer_end - g->buffer);
201  g->buffer += offset;
202  break;
203  case SEEK_END:
204  offset = av_clip(offset, -(g->buffer_end - g->buffer_start), 0);
205  g->buffer = g->buffer_end + offset;
206  break;
207  case SEEK_SET:
208  offset = av_clip(offset, 0, g->buffer_end - g->buffer_start);
209  g->buffer = g->buffer_start + offset;
210  break;
211  default:
212  return AVERROR(EINVAL);
213  }
214  return bytestream2_tell(g);
215 }
216 
218  int offset,
219  int whence)
220 {
221  p->eof = 0;
222  switch (whence) {
223  case SEEK_CUR:
224  if (p->buffer_end - p->buffer < offset)
225  p->eof = 1;
226  offset = av_clip(offset, -(p->buffer - p->buffer_start),
227  p->buffer_end - p->buffer);
228  p->buffer += offset;
229  break;
230  case SEEK_END:
231  if (offset > 0)
232  p->eof = 1;
233  offset = av_clip(offset, -(p->buffer_end - p->buffer_start), 0);
234  p->buffer = p->buffer_end + offset;
235  break;
236  case SEEK_SET:
237  if (p->buffer_end - p->buffer_start < offset)
238  p->eof = 1;
239  offset = av_clip(offset, 0, p->buffer_end - p->buffer_start);
240  p->buffer = p->buffer_start + offset;
241  break;
242  default:
243  return AVERROR(EINVAL);
244  }
245  return bytestream2_tell_p(p);
246 }
247 
249  uint8_t *dst,
250  unsigned int size)
251 {
252  int size2 = FFMIN(g->buffer_end - g->buffer, size);
253  memcpy(dst, g->buffer, size2);
254  g->buffer += size2;
255  return size2;
256 }
257 
259  uint8_t *dst,
260  unsigned int size)
261 {
262  memcpy(dst, g->buffer, size);
263  g->buffer += size;
264  return size;
265 }
266 
268  const uint8_t *src,
269  unsigned int size)
270 {
271  int size2;
272  if (p->eof)
273  return 0;
274  size2 = FFMIN(p->buffer_end - p->buffer, size);
275  if (size2 != size)
276  p->eof = 1;
277  memcpy(p->buffer, src, size2);
278  p->buffer += size2;
279  return size2;
280 }
281 
283  const uint8_t *src,
284  unsigned int size)
285 {
286  memcpy(p->buffer, src, size);
287  p->buffer += size;
288  return size;
289 }
290 
292  const uint8_t c,
293  unsigned int size)
294 {
295  int size2;
296  if (p->eof)
297  return;
298  size2 = FFMIN(p->buffer_end - p->buffer, size);
299  if (size2 != size)
300  p->eof = 1;
301  memset(p->buffer, c, size2);
302  p->buffer += size2;
303 }
304 
306  const uint8_t c,
307  unsigned int size)
308 {
309  memset(p->buffer, c, size);
310  p->buffer += size;
311 }
312 
314 {
315  return p->eof;
316 }
317 
318 static av_always_inline unsigned int bytestream_get_buffer(const uint8_t **b,
319  uint8_t *dst,
320  unsigned int size)
321 {
322  memcpy(dst, *b, size);
323  (*b) += size;
324  return size;
325 }
326 
328  const uint8_t *src,
329  unsigned int size)
330 {
331  memcpy(*b, src, size);
332  (*b) += size;
333 }
334 
335 #endif /* AVCODEC_BYTESTREAM_H */
#define AV_RB8(x)
Definition: intreadwrite.h:357
#define AV_WL64(p, d)
Definition: intreadwrite.h:299
static av_always_inline void bytestream2_set_bufferu(PutByteContext *p, const uint8_t c, unsigned int size)
Definition: bytestream.h:305
static av_always_inline void bytestream2_set_buffer(PutByteContext *p, const uint8_t c, unsigned int size)
Definition: bytestream.h:291
int size
#define AV_RB64
Definition: intreadwrite.h:164
static av_always_inline void bytestream2_init_writer(PutByteContext *p, uint8_t *buf, int buf_size)
Definition: bytestream.h:139
#define AV_WB8(p, d)
Definition: intreadwrite.h:358
#define AV_RB24
Definition: intreadwrite.h:64
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:130
#define AV_RL16
Definition: intreadwrite.h:42
static av_always_inline unsigned int bytestream2_get_bufferu(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:258
#define AV_RL64
Definition: intreadwrite.h:173
#define AV_WL24(p, d)
Definition: intreadwrite.h:426
uint8_t
#define AV_WB32(p, d)
Definition: intreadwrite.h:239
#define DEF(type, name, bytes, read, write)
Definition: bytestream.h:41
#define AV_RB32
Definition: intreadwrite.h:130
#define b
Definition: input.c:52
#define AV_WL32(p, d)
Definition: intreadwrite.h:255
struct GetByteContext GetByteContext
const uint8_t * buffer
Definition: bytestream.h:33
static av_always_inline void bytestream2_skipu(GetByteContext *g, unsigned int size)
Definition: bytestream.h:165
static av_always_inline unsigned int bytestream2_get_bytes_left_p(PutByteContext *p)
Definition: bytestream.h:154
#define AV_RB16
Definition: intreadwrite.h:53
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:159
#define AV_WB64(p, d)
Definition: intreadwrite.h:275
g
Definition: yuv2rgb.c:540
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:248
static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:149
static av_always_inline int bytestream2_tell_p(PutByteContext *p)
Definition: bytestream.h:188
const uint8_t * buffer_end
Definition: bytestream.h:33
static av_always_inline void bytestream2_skip_p(PutByteContext *p, unsigned int size)
Definition: bytestream.h:171
uint8_t * buffer_start
Definition: bytestream.h:37
#define AV_WB24(p, d)
Definition: intreadwrite.h:412
#define AV_RL32
Definition: intreadwrite.h:146
static av_always_inline unsigned int bytestream_get_buffer(const uint8_t **b, uint8_t *dst, unsigned int size)
Definition: bytestream.h:318
static av_always_inline unsigned int bytestream2_put_buffer(PutByteContext *p, const uint8_t *src, unsigned int size)
Definition: bytestream.h:267
static av_always_inline int bytestream2_seek_p(PutByteContext *p, int offset, int whence)
Definition: bytestream.h:217
static av_always_inline int bytestream2_tell(GetByteContext *g)
Definition: bytestream.h:183
uint8_t * buffer
Definition: bytestream.h:37
static av_always_inline unsigned int bytestream2_put_bufferu(PutByteContext *p, const uint8_t *src, unsigned int size)
Definition: bytestream.h:282
const uint8_t * buffer_start
Definition: bytestream.h:33
#define AV_WB16(p, d)
Definition: intreadwrite.h:213
#define AV_RL24
Definition: intreadwrite.h:78
common internal and external API header
static av_always_inline unsigned int bytestream2_get_eof(PutByteContext *p)
Definition: bytestream.h:313
struct PutByteContext PutByteContext
static av_always_inline void bytestream_put_buffer(uint8_t **b, const uint8_t *src, unsigned int size)
Definition: bytestream.h:327
static av_always_inline int bytestream2_seek(GetByteContext *g, int offset, int whence)
Definition: bytestream.h:193
#define AV_WL16(p, d)
Definition: intreadwrite.h:225
uint8_t * buffer_end
Definition: bytestream.h:37