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