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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 FFmpeg.
7 *
8 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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/avassert.h"
30#include "libavutil/common.h"
31#include "libavutil/intreadwrite.h"
32
33typedef struct GetByteContext {
34 const uint8_t *buffer, *buffer_end, *buffer_start;
35} GetByteContext;
36
37typedef struct PutByteContext {
38 uint8_t *buffer, *buffer_end, *buffer_start;
39 int eof;
40} PutByteContext;
41
42#define DEF(type, name, bytes, read, write) \
43static av_always_inline type bytestream_get_ ## name(const uint8_t **b) \
44{ \
45 (*b) += bytes; \
46 return read(*b - bytes); \
47} \
48static av_always_inline void bytestream_put_ ## name(uint8_t **b, \
49 const type value) \
50{ \
51 write(*b, value); \
52 (*b) += bytes; \
53} \
54static av_always_inline void bytestream2_put_ ## name ## u(PutByteContext *p, \
55 const type value) \
56{ \
57 bytestream_put_ ## name(&p->buffer, value); \
58} \
59static av_always_inline void bytestream2_put_ ## name(PutByteContext *p, \
60 const type value) \
61{ \
62 if (!p->eof && (p->buffer_end - p->buffer >= bytes)) { \
63 write(p->buffer, value); \
64 p->buffer += bytes; \
65 } else \
66 p->eof = 1; \
67} \
68static av_always_inline type bytestream2_get_ ## name ## u(GetByteContext *g) \
69{ \
70 return bytestream_get_ ## name(&g->buffer); \
71} \
72static av_always_inline type bytestream2_get_ ## name(GetByteContext *g) \
73{ \
74 if (g->buffer_end - g->buffer < bytes) { \
75 g->buffer = g->buffer_end; \
76 return 0; \
77 } \
78 return bytestream2_get_ ## name ## u(g); \
79} \
80static av_always_inline type bytestream2_peek_ ## name(GetByteContext *g) \
81{ \
82 if (g->buffer_end - g->buffer < bytes) \
83 return 0; \
84 return read(g->buffer); \
85}
86
87DEF(uint64_t, le64, 8, AV_RL64, AV_WL64)
88DEF(unsigned int, le32, 4, AV_RL32, AV_WL32)
89DEF(unsigned int, le24, 3, AV_RL24, AV_WL24)
90DEF(unsigned int, le16, 2, AV_RL16, AV_WL16)
91DEF(uint64_t, be64, 8, AV_RB64, AV_WB64)
92DEF(unsigned int, be32, 4, AV_RB32, AV_WB32)
93DEF(unsigned int, be24, 3, AV_RB24, AV_WB24)
94DEF(unsigned int, be16, 2, AV_RB16, AV_WB16)
95DEF(unsigned int, byte, 1, AV_RB8 , AV_WB8)
96
97#if AV_HAVE_BIGENDIAN
98# define bytestream2_get_ne16 bytestream2_get_be16
99# define bytestream2_get_ne24 bytestream2_get_be24
100# define bytestream2_get_ne32 bytestream2_get_be32
101# define bytestream2_get_ne64 bytestream2_get_be64
102# define bytestream2_get_ne16u bytestream2_get_be16u
103# define bytestream2_get_ne24u bytestream2_get_be24u
104# define bytestream2_get_ne32u bytestream2_get_be32u
105# define bytestream2_get_ne64u bytestream2_get_be64u
106# define bytestream2_put_ne16 bytestream2_put_be16
107# define bytestream2_put_ne24 bytestream2_put_be24
108# define bytestream2_put_ne32 bytestream2_put_be32
109# define bytestream2_put_ne64 bytestream2_put_be64
110# define bytestream2_peek_ne16 bytestream2_peek_be16
111# define bytestream2_peek_ne24 bytestream2_peek_be24
112# define bytestream2_peek_ne32 bytestream2_peek_be32
113# define bytestream2_peek_ne64 bytestream2_peek_be64
114#else
115# define bytestream2_get_ne16 bytestream2_get_le16
116# define bytestream2_get_ne24 bytestream2_get_le24
117# define bytestream2_get_ne32 bytestream2_get_le32
118# define bytestream2_get_ne64 bytestream2_get_le64
119# define bytestream2_get_ne16u bytestream2_get_le16u
120# define bytestream2_get_ne24u bytestream2_get_le24u
121# define bytestream2_get_ne32u bytestream2_get_le32u
122# define bytestream2_get_ne64u bytestream2_get_le64u
123# define bytestream2_put_ne16 bytestream2_put_le16
124# define bytestream2_put_ne24 bytestream2_put_le24
125# define bytestream2_put_ne32 bytestream2_put_le32
126# define bytestream2_put_ne64 bytestream2_put_le64
127# define bytestream2_peek_ne16 bytestream2_peek_le16
128# define bytestream2_peek_ne24 bytestream2_peek_le24
129# define bytestream2_peek_ne32 bytestream2_peek_le32
130# define bytestream2_peek_ne64 bytestream2_peek_le64
131#endif
132
133static av_always_inline void bytestream2_init(GetByteContext *g,
134 const uint8_t *buf,
135 int buf_size)
136{
137 av_assert0(buf_size >= 0);
138 g->buffer = buf;
139 g->buffer_start = buf;
140 g->buffer_end = buf + buf_size;
141}
142
143static av_always_inline void bytestream2_init_writer(PutByteContext *p,
144 uint8_t *buf,
145 int buf_size)
146{
147 av_assert0(buf_size >= 0);
148 p->buffer = buf;
149 p->buffer_start = buf;
150 p->buffer_end = buf + buf_size;
151 p->eof = 0;
152}
153
154static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
155{
156 return g->buffer_end - g->buffer;
157}
158
159static av_always_inline unsigned int bytestream2_get_bytes_left_p(PutByteContext *p)
160{
161 return p->buffer_end - p->buffer;
162}
163
164static av_always_inline void bytestream2_skip(GetByteContext *g,
165 unsigned int size)
166{
167 g->buffer += FFMIN(g->buffer_end - g->buffer, size);
168}
169
170static av_always_inline void bytestream2_skipu(GetByteContext *g,
171 unsigned int size)
172{
173 g->buffer += size;
174}
175
176static av_always_inline void bytestream2_skip_p(PutByteContext *p,
177 unsigned int size)
178{
179 int size2;
180 if (p->eof)
181 return;
182 size2 = FFMIN(p->buffer_end - p->buffer, size);
183 if (size2 != size)
184 p->eof = 1;
185 p->buffer += size2;
186}
187
188static av_always_inline int bytestream2_tell(GetByteContext *g)
189{
190 return (int)(g->buffer - g->buffer_start);
191}
192
193static av_always_inline int bytestream2_tell_p(PutByteContext *p)
194{
195 return (int)(p->buffer - p->buffer_start);
196}
197
198static av_always_inline int bytestream2_size(GetByteContext *g)
199{
200 return (int)(g->buffer_end - g->buffer_start);
201}
202
203static av_always_inline int bytestream2_size_p(PutByteContext *p)
204{
205 return (int)(p->buffer_end - p->buffer_start);
206}
207
208static av_always_inline int bytestream2_seek(GetByteContext *g,
209 int offset,
210 int whence)
211{
212 switch (whence) {
213 case SEEK_CUR:
214 offset = av_clip(offset, -(g->buffer - g->buffer_start),
215 g->buffer_end - g->buffer);
216 g->buffer += offset;
217 break;
218 case SEEK_END:
219 offset = av_clip(offset, -(g->buffer_end - g->buffer_start), 0);
220 g->buffer = g->buffer_end + offset;
221 break;
222 case SEEK_SET:
223 offset = av_clip(offset, 0, g->buffer_end - g->buffer_start);
224 g->buffer = g->buffer_start + offset;
225 break;
226 default:
227 return AVERROR(EINVAL);
228 }
229 return bytestream2_tell(g);
230}
231
232static av_always_inline int bytestream2_seek_p(PutByteContext *p,
233 int offset,
234 int whence)
235{
236 p->eof = 0;
237 switch (whence) {
238 case SEEK_CUR:
239 if (p->buffer_end - p->buffer < offset)
240 p->eof = 1;
241 offset = av_clip(offset, -(p->buffer - p->buffer_start),
242 p->buffer_end - p->buffer);
243 p->buffer += offset;
244 break;
245 case SEEK_END:
246 if (offset > 0)
247 p->eof = 1;
248 offset = av_clip(offset, -(p->buffer_end - p->buffer_start), 0);
249 p->buffer = p->buffer_end + offset;
250 break;
251 case SEEK_SET:
252 if (p->buffer_end - p->buffer_start < offset)
253 p->eof = 1;
254 offset = av_clip(offset, 0, p->buffer_end - p->buffer_start);
255 p->buffer = p->buffer_start + offset;
256 break;
257 default:
258 return AVERROR(EINVAL);
259 }
260 return bytestream2_tell_p(p);
261}
262
263static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g,
264 uint8_t *dst,
265 unsigned int size)
266{
267 int size2 = FFMIN(g->buffer_end - g->buffer, size);
268 memcpy(dst, g->buffer, size2);
269 g->buffer += size2;
270 return size2;
271}
272
273static av_always_inline unsigned int bytestream2_get_bufferu(GetByteContext *g,
274 uint8_t *dst,
275 unsigned int size)
276{
277 memcpy(dst, g->buffer, size);
278 g->buffer += size;
279 return size;
280}
281
282static av_always_inline unsigned int bytestream2_put_buffer(PutByteContext *p,
283 const uint8_t *src,
284 unsigned int size)
285{
286 int size2;
287 if (p->eof)
288 return 0;
289 size2 = FFMIN(p->buffer_end - p->buffer, size);
290 if (size2 != size)
291 p->eof = 1;
292 memcpy(p->buffer, src, size2);
293 p->buffer += size2;
294 return size2;
295}
296
297static av_always_inline unsigned int bytestream2_put_bufferu(PutByteContext *p,
298 const uint8_t *src,
299 unsigned int size)
300{
301 memcpy(p->buffer, src, size);
302 p->buffer += size;
303 return size;
304}
305
306static av_always_inline void bytestream2_set_buffer(PutByteContext *p,
307 const uint8_t c,
308 unsigned int size)
309{
310 int size2;
311 if (p->eof)
312 return;
313 size2 = FFMIN(p->buffer_end - p->buffer, size);
314 if (size2 != size)
315 p->eof = 1;
316 memset(p->buffer, c, size2);
317 p->buffer += size2;
318}
319
320static av_always_inline void bytestream2_set_bufferu(PutByteContext *p,
321 const uint8_t c,
322 unsigned int size)
323{
324 memset(p->buffer, c, size);
325 p->buffer += size;
326}
327
328static av_always_inline unsigned int bytestream2_get_eof(PutByteContext *p)
329{
330 return p->eof;
331}
332
333static av_always_inline unsigned int bytestream2_copy_bufferu(PutByteContext *p,
334 GetByteContext *g,
335 unsigned int size)
336{
337 memcpy(p->buffer, g->buffer, size);
338 p->buffer += size;
339 g->buffer += size;
340 return size;
341}
342
343static av_always_inline unsigned int bytestream2_copy_buffer(PutByteContext *p,
344 GetByteContext *g,
345 unsigned int size)
346{
347 int size2;
348
349 if (p->eof)
350 return 0;
351 size = FFMIN(g->buffer_end - g->buffer, size);
352 size2 = FFMIN(p->buffer_end - p->buffer, size);
353 if (size2 != size)
354 p->eof = 1;
355
356 return bytestream2_copy_bufferu(p, g, size2);
357}
358
359static av_always_inline unsigned int bytestream_get_buffer(const uint8_t **b,
360 uint8_t *dst,
361 unsigned int size)
362{
363 memcpy(dst, *b, size);
364 (*b) += size;
365 return size;
366}
367
368static av_always_inline void bytestream_put_buffer(uint8_t **b,
369 const uint8_t *src,
370 unsigned int size)
371{
372 memcpy(*b, src, size);
373 (*b) += size;
374}
375
376#endif /* AVCODEC_BYTESTREAM_H */
377
generated by cgit at 2024-05-17 05:47:53 (GMT)