| 1 | /* |
| 2 | * Microsoft Screen 3 (aka Microsoft ATC Screen) decoder |
| 3 | * Copyright (c) 2012 Konstantin Shishkov |
| 4 | * |
| 5 | * This file is part of FFmpeg. |
| 6 | * |
| 7 | * FFmpeg is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU Lesser General Public |
| 9 | * License as published by the Free Software Foundation; either |
| 10 | * version 2.1 of the License, or (at your option) any later version. |
| 11 | * |
| 12 | * FFmpeg is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public |
| 18 | * License along with FFmpeg; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 20 | */ |
| 21 | |
| 22 | /** |
| 23 | * @file |
| 24 | * Microsoft Screen 3 (aka Microsoft ATC Screen) decoder |
| 25 | */ |
| 26 | |
| 27 | #include "avcodec.h" |
| 28 | #include "bytestream.h" |
| 29 | #include "internal.h" |
| 30 | #include "mathops.h" |
| 31 | #include "mss34dsp.h" |
| 32 | |
| 33 | #define HEADER_SIZE 27 |
| 34 | |
| 35 | #define MODEL2_SCALE 13 |
| 36 | #define MODEL_SCALE 15 |
| 37 | #define MODEL256_SEC_SCALE 9 |
| 38 | |
| 39 | typedef struct Model2 { |
| 40 | int upd_val, till_rescale; |
| 41 | unsigned zero_freq, zero_weight; |
| 42 | unsigned total_freq, total_weight; |
| 43 | } Model2; |
| 44 | |
| 45 | typedef struct Model { |
| 46 | int weights[16], freqs[16]; |
| 47 | int num_syms; |
| 48 | int tot_weight; |
| 49 | int upd_val, max_upd_val, till_rescale; |
| 50 | } Model; |
| 51 | |
| 52 | typedef struct Model256 { |
| 53 | int weights[256], freqs[256]; |
| 54 | int tot_weight; |
| 55 | int secondary[68]; |
| 56 | int sec_size; |
| 57 | int upd_val, max_upd_val, till_rescale; |
| 58 | } Model256; |
| 59 | |
| 60 | #define RAC_BOTTOM 0x01000000 |
| 61 | typedef struct RangeCoder { |
| 62 | const uint8_t *src, *src_end; |
| 63 | |
| 64 | uint32_t range, low; |
| 65 | int got_error; |
| 66 | } RangeCoder; |
| 67 | |
| 68 | enum BlockType { |
| 69 | FILL_BLOCK = 0, |
| 70 | IMAGE_BLOCK, |
| 71 | DCT_BLOCK, |
| 72 | HAAR_BLOCK, |
| 73 | SKIP_BLOCK |
| 74 | }; |
| 75 | |
| 76 | typedef struct BlockTypeContext { |
| 77 | int last_type; |
| 78 | Model bt_model[5]; |
| 79 | } BlockTypeContext; |
| 80 | |
| 81 | typedef struct FillBlockCoder { |
| 82 | int fill_val; |
| 83 | Model coef_model; |
| 84 | } FillBlockCoder; |
| 85 | |
| 86 | typedef struct ImageBlockCoder { |
| 87 | Model256 esc_model, vec_entry_model; |
| 88 | Model vec_size_model; |
| 89 | Model vq_model[125]; |
| 90 | } ImageBlockCoder; |
| 91 | |
| 92 | typedef struct DCTBlockCoder { |
| 93 | int *prev_dc; |
| 94 | int prev_dc_stride; |
| 95 | int prev_dc_height; |
| 96 | int quality; |
| 97 | uint16_t qmat[64]; |
| 98 | Model dc_model; |
| 99 | Model2 sign_model; |
| 100 | Model256 ac_model; |
| 101 | } DCTBlockCoder; |
| 102 | |
| 103 | typedef struct HaarBlockCoder { |
| 104 | int quality, scale; |
| 105 | Model256 coef_model; |
| 106 | Model coef_hi_model; |
| 107 | } HaarBlockCoder; |
| 108 | |
| 109 | typedef struct MSS3Context { |
| 110 | AVCodecContext *avctx; |
| 111 | AVFrame *pic; |
| 112 | |
| 113 | int got_error; |
| 114 | RangeCoder coder; |
| 115 | BlockTypeContext btype[3]; |
| 116 | FillBlockCoder fill_coder[3]; |
| 117 | ImageBlockCoder image_coder[3]; |
| 118 | DCTBlockCoder dct_coder[3]; |
| 119 | HaarBlockCoder haar_coder[3]; |
| 120 | |
| 121 | int dctblock[64]; |
| 122 | int hblock[16 * 16]; |
| 123 | } MSS3Context; |
| 124 | |
| 125 | |
| 126 | static void model2_reset(Model2 *m) |
| 127 | { |
| 128 | m->zero_weight = 1; |
| 129 | m->total_weight = 2; |
| 130 | m->zero_freq = 0x1000; |
| 131 | m->total_freq = 0x2000; |
| 132 | m->upd_val = 4; |
| 133 | m->till_rescale = 4; |
| 134 | } |
| 135 | |
| 136 | static void model2_update(Model2 *m, int bit) |
| 137 | { |
| 138 | unsigned scale; |
| 139 | |
| 140 | if (!bit) |
| 141 | m->zero_weight++; |
| 142 | m->till_rescale--; |
| 143 | if (m->till_rescale) |
| 144 | return; |
| 145 | |
| 146 | m->total_weight += m->upd_val; |
| 147 | if (m->total_weight > 0x2000) { |
| 148 | m->total_weight = (m->total_weight + 1) >> 1; |
| 149 | m->zero_weight = (m->zero_weight + 1) >> 1; |
| 150 | if (m->total_weight == m->zero_weight) |
| 151 | m->total_weight = m->zero_weight + 1; |
| 152 | } |
| 153 | m->upd_val = m->upd_val * 5 >> 2; |
| 154 | if (m->upd_val > 64) |
| 155 | m->upd_val = 64; |
| 156 | scale = 0x80000000u / m->total_weight; |
| 157 | m->zero_freq = m->zero_weight * scale >> 18; |
| 158 | m->total_freq = m->total_weight * scale >> 18; |
| 159 | m->till_rescale = m->upd_val; |
| 160 | } |
| 161 | |
| 162 | static void model_update(Model *m, int val) |
| 163 | { |
| 164 | int i, sum = 0; |
| 165 | unsigned scale; |
| 166 | |
| 167 | m->weights[val]++; |
| 168 | m->till_rescale--; |
| 169 | if (m->till_rescale) |
| 170 | return; |
| 171 | m->tot_weight += m->upd_val; |
| 172 | |
| 173 | if (m->tot_weight > 0x8000) { |
| 174 | m->tot_weight = 0; |
| 175 | for (i = 0; i < m->num_syms; i++) { |
| 176 | m->weights[i] = (m->weights[i] + 1) >> 1; |
| 177 | m->tot_weight += m->weights[i]; |
| 178 | } |
| 179 | } |
| 180 | scale = 0x80000000u / m->tot_weight; |
| 181 | for (i = 0; i < m->num_syms; i++) { |
| 182 | m->freqs[i] = sum * scale >> 16; |
| 183 | sum += m->weights[i]; |
| 184 | } |
| 185 | |
| 186 | m->upd_val = m->upd_val * 5 >> 2; |
| 187 | if (m->upd_val > m->max_upd_val) |
| 188 | m->upd_val = m->max_upd_val; |
| 189 | m->till_rescale = m->upd_val; |
| 190 | } |
| 191 | |
| 192 | static void model_reset(Model *m) |
| 193 | { |
| 194 | int i; |
| 195 | |
| 196 | m->tot_weight = 0; |
| 197 | for (i = 0; i < m->num_syms - 1; i++) |
| 198 | m->weights[i] = 1; |
| 199 | m->weights[m->num_syms - 1] = 0; |
| 200 | |
| 201 | m->upd_val = m->num_syms; |
| 202 | m->till_rescale = 1; |
| 203 | model_update(m, m->num_syms - 1); |
| 204 | m->till_rescale = |
| 205 | m->upd_val = (m->num_syms + 6) >> 1; |
| 206 | } |
| 207 | |
| 208 | static av_cold void model_init(Model *m, int num_syms) |
| 209 | { |
| 210 | m->num_syms = num_syms; |
| 211 | m->max_upd_val = 8 * num_syms + 48; |
| 212 | |
| 213 | model_reset(m); |
| 214 | } |
| 215 | |
| 216 | static void model256_update(Model256 *m, int val) |
| 217 | { |
| 218 | int i, sum = 0; |
| 219 | unsigned scale; |
| 220 | int send, sidx = 1; |
| 221 | |
| 222 | m->weights[val]++; |
| 223 | m->till_rescale--; |
| 224 | if (m->till_rescale) |
| 225 | return; |
| 226 | m->tot_weight += m->upd_val; |
| 227 | |
| 228 | if (m->tot_weight > 0x8000) { |
| 229 | m->tot_weight = 0; |
| 230 | for (i = 0; i < 256; i++) { |
| 231 | m->weights[i] = (m->weights[i] + 1) >> 1; |
| 232 | m->tot_weight += m->weights[i]; |
| 233 | } |
| 234 | } |
| 235 | scale = 0x80000000u / m->tot_weight; |
| 236 | m->secondary[0] = 0; |
| 237 | for (i = 0; i < 256; i++) { |
| 238 | m->freqs[i] = sum * scale >> 16; |
| 239 | sum += m->weights[i]; |
| 240 | send = m->freqs[i] >> MODEL256_SEC_SCALE; |
| 241 | while (sidx <= send) |
| 242 | m->secondary[sidx++] = i - 1; |
| 243 | } |
| 244 | while (sidx < m->sec_size) |
| 245 | m->secondary[sidx++] = 255; |
| 246 | |
| 247 | m->upd_val = m->upd_val * 5 >> 2; |
| 248 | if (m->upd_val > m->max_upd_val) |
| 249 | m->upd_val = m->max_upd_val; |
| 250 | m->till_rescale = m->upd_val; |
| 251 | } |
| 252 | |
| 253 | static void model256_reset(Model256 *m) |
| 254 | { |
| 255 | int i; |
| 256 | |
| 257 | for (i = 0; i < 255; i++) |
| 258 | m->weights[i] = 1; |
| 259 | m->weights[255] = 0; |
| 260 | |
| 261 | m->tot_weight = 0; |
| 262 | m->upd_val = 256; |
| 263 | m->till_rescale = 1; |
| 264 | model256_update(m, 255); |
| 265 | m->till_rescale = |
| 266 | m->upd_val = (256 + 6) >> 1; |
| 267 | } |
| 268 | |
| 269 | static av_cold void model256_init(Model256 *m) |
| 270 | { |
| 271 | m->max_upd_val = 8 * 256 + 48; |
| 272 | m->sec_size = (1 << 6) + 2; |
| 273 | |
| 274 | model256_reset(m); |
| 275 | } |
| 276 | |
| 277 | static void rac_init(RangeCoder *c, const uint8_t *src, int size) |
| 278 | { |
| 279 | int i; |
| 280 | |
| 281 | c->src = src; |
| 282 | c->src_end = src + size; |
| 283 | c->low = 0; |
| 284 | for (i = 0; i < FFMIN(size, 4); i++) |
| 285 | c->low = (c->low << 8) | *c->src++; |
| 286 | c->range = 0xFFFFFFFF; |
| 287 | c->got_error = 0; |
| 288 | } |
| 289 | |
| 290 | static void rac_normalise(RangeCoder *c) |
| 291 | { |
| 292 | for (;;) { |
| 293 | c->range <<= 8; |
| 294 | c->low <<= 8; |
| 295 | if (c->src < c->src_end) { |
| 296 | c->low |= *c->src++; |
| 297 | } else if (!c->low) { |
| 298 | c->got_error = 1; |
| 299 | c->low = 1; |
| 300 | } |
| 301 | if (c->range >= RAC_BOTTOM) |
| 302 | return; |
| 303 | } |
| 304 | } |
| 305 | |
| 306 | static int rac_get_bit(RangeCoder *c) |
| 307 | { |
| 308 | int bit; |
| 309 | |
| 310 | c->range >>= 1; |
| 311 | |
| 312 | bit = (c->range <= c->low); |
| 313 | if (bit) |
| 314 | c->low -= c->range; |
| 315 | |
| 316 | if (c->range < RAC_BOTTOM) |
| 317 | rac_normalise(c); |
| 318 | |
| 319 | return bit; |
| 320 | } |
| 321 | |
| 322 | static int rac_get_bits(RangeCoder *c, int nbits) |
| 323 | { |
| 324 | int val; |
| 325 | |
| 326 | c->range >>= nbits; |
| 327 | val = c->low / c->range; |
| 328 | c->low -= c->range * val; |
| 329 | |
| 330 | if (c->range < RAC_BOTTOM) |
| 331 | rac_normalise(c); |
| 332 | |
| 333 | return val; |
| 334 | } |
| 335 | |
| 336 | static int rac_get_model2_sym(RangeCoder *c, Model2 *m) |
| 337 | { |
| 338 | int bit, helper; |
| 339 | |
| 340 | helper = m->zero_freq * (c->range >> MODEL2_SCALE); |
| 341 | bit = (c->low >= helper); |
| 342 | if (bit) { |
| 343 | c->low -= helper; |
| 344 | c->range -= helper; |
| 345 | } else { |
| 346 | c->range = helper; |
| 347 | } |
| 348 | |
| 349 | if (c->range < RAC_BOTTOM) |
| 350 | rac_normalise(c); |
| 351 | |
| 352 | model2_update(m, bit); |
| 353 | |
| 354 | return bit; |
| 355 | } |
| 356 | |
| 357 | static int rac_get_model_sym(RangeCoder *c, Model *m) |
| 358 | { |
| 359 | int prob, prob2, helper, val; |
| 360 | int end, end2; |
| 361 | |
| 362 | prob = 0; |
| 363 | prob2 = c->range; |
| 364 | c->range >>= MODEL_SCALE; |
| 365 | val = 0; |
| 366 | end = m->num_syms >> 1; |
| 367 | end2 = m->num_syms; |
| 368 | do { |
| 369 | helper = m->freqs[end] * c->range; |
| 370 | if (helper <= c->low) { |
| 371 | val = end; |
| 372 | prob = helper; |
| 373 | } else { |
| 374 | end2 = end; |
| 375 | prob2 = helper; |
| 376 | } |
| 377 | end = (end2 + val) >> 1; |
| 378 | } while (end != val); |
| 379 | c->low -= prob; |
| 380 | c->range = prob2 - prob; |
| 381 | if (c->range < RAC_BOTTOM) |
| 382 | rac_normalise(c); |
| 383 | |
| 384 | model_update(m, val); |
| 385 | |
| 386 | return val; |
| 387 | } |
| 388 | |
| 389 | static int rac_get_model256_sym(RangeCoder *c, Model256 *m) |
| 390 | { |
| 391 | int prob, prob2, helper, val; |
| 392 | int start, end; |
| 393 | int ssym; |
| 394 | |
| 395 | prob2 = c->range; |
| 396 | c->range >>= MODEL_SCALE; |
| 397 | |
| 398 | helper = c->low / c->range; |
| 399 | ssym = helper >> MODEL256_SEC_SCALE; |
| 400 | val = m->secondary[ssym]; |
| 401 | |
| 402 | end = start = m->secondary[ssym + 1] + 1; |
| 403 | while (end > val + 1) { |
| 404 | ssym = (end + val) >> 1; |
| 405 | if (m->freqs[ssym] <= helper) { |
| 406 | end = start; |
| 407 | val = ssym; |
| 408 | } else { |
| 409 | end = (end + val) >> 1; |
| 410 | start = ssym; |
| 411 | } |
| 412 | } |
| 413 | prob = m->freqs[val] * c->range; |
| 414 | if (val != 255) |
| 415 | prob2 = m->freqs[val + 1] * c->range; |
| 416 | |
| 417 | c->low -= prob; |
| 418 | c->range = prob2 - prob; |
| 419 | if (c->range < RAC_BOTTOM) |
| 420 | rac_normalise(c); |
| 421 | |
| 422 | model256_update(m, val); |
| 423 | |
| 424 | return val; |
| 425 | } |
| 426 | |
| 427 | static int decode_block_type(RangeCoder *c, BlockTypeContext *bt) |
| 428 | { |
| 429 | bt->last_type = rac_get_model_sym(c, &bt->bt_model[bt->last_type]); |
| 430 | |
| 431 | return bt->last_type; |
| 432 | } |
| 433 | |
| 434 | static int decode_coeff(RangeCoder *c, Model *m) |
| 435 | { |
| 436 | int val, sign; |
| 437 | |
| 438 | val = rac_get_model_sym(c, m); |
| 439 | if (val) { |
| 440 | sign = rac_get_bit(c); |
| 441 | if (val > 1) { |
| 442 | val--; |
| 443 | val = (1 << val) + rac_get_bits(c, val); |
| 444 | } |
| 445 | if (!sign) |
| 446 | val = -val; |
| 447 | } |
| 448 | |
| 449 | return val; |
| 450 | } |
| 451 | |
| 452 | static void decode_fill_block(RangeCoder *c, FillBlockCoder *fc, |
| 453 | uint8_t *dst, int stride, int block_size) |
| 454 | { |
| 455 | int i; |
| 456 | |
| 457 | fc->fill_val += decode_coeff(c, &fc->coef_model); |
| 458 | |
| 459 | for (i = 0; i < block_size; i++, dst += stride) |
| 460 | memset(dst, fc->fill_val, block_size); |
| 461 | } |
| 462 | |
| 463 | static void decode_image_block(RangeCoder *c, ImageBlockCoder *ic, |
| 464 | uint8_t *dst, int stride, int block_size) |
| 465 | { |
| 466 | int i, j; |
| 467 | int vec_size; |
| 468 | int vec[4]; |
| 469 | int prev_line[16]; |
| 470 | int A, B, C; |
| 471 | |
| 472 | vec_size = rac_get_model_sym(c, &ic->vec_size_model) + 2; |
| 473 | for (i = 0; i < vec_size; i++) |
| 474 | vec[i] = rac_get_model256_sym(c, &ic->vec_entry_model); |
| 475 | for (; i < 4; i++) |
| 476 | vec[i] = 0; |
| 477 | memset(prev_line, 0, sizeof(prev_line)); |
| 478 | |
| 479 | for (j = 0; j < block_size; j++) { |
| 480 | A = 0; |
| 481 | B = 0; |
| 482 | for (i = 0; i < block_size; i++) { |
| 483 | C = B; |
| 484 | B = prev_line[i]; |
| 485 | A = rac_get_model_sym(c, &ic->vq_model[A + B * 5 + C * 25]); |
| 486 | |
| 487 | prev_line[i] = A; |
| 488 | if (A < 4) |
| 489 | dst[i] = vec[A]; |
| 490 | else |
| 491 | dst[i] = rac_get_model256_sym(c, &ic->esc_model); |
| 492 | } |
| 493 | dst += stride; |
| 494 | } |
| 495 | } |
| 496 | |
| 497 | static int decode_dct(RangeCoder *c, DCTBlockCoder *bc, int *block, |
| 498 | int bx, int by) |
| 499 | { |
| 500 | int skip, val, sign, pos = 1, zz_pos, dc; |
| 501 | int blk_pos = bx + by * bc->prev_dc_stride; |
| 502 | |
| 503 | memset(block, 0, sizeof(*block) * 64); |
| 504 | |
| 505 | dc = decode_coeff(c, &bc->dc_model); |
| 506 | if (by) { |
| 507 | if (bx) { |
| 508 | int l, tl, t; |
| 509 | |
| 510 | l = bc->prev_dc[blk_pos - 1]; |
| 511 | tl = bc->prev_dc[blk_pos - 1 - bc->prev_dc_stride]; |
| 512 | t = bc->prev_dc[blk_pos - bc->prev_dc_stride]; |
| 513 | |
| 514 | if (FFABS(t - tl) <= FFABS(l - tl)) |
| 515 | dc += l; |
| 516 | else |
| 517 | dc += t; |
| 518 | } else { |
| 519 | dc += bc->prev_dc[blk_pos - bc->prev_dc_stride]; |
| 520 | } |
| 521 | } else if (bx) { |
| 522 | dc += bc->prev_dc[bx - 1]; |
| 523 | } |
| 524 | bc->prev_dc[blk_pos] = dc; |
| 525 | block[0] = dc * bc->qmat[0]; |
| 526 | |
| 527 | while (pos < 64) { |
| 528 | val = rac_get_model256_sym(c, &bc->ac_model); |
| 529 | if (!val) |
| 530 | return 0; |
| 531 | if (val == 0xF0) { |
| 532 | pos += 16; |
| 533 | continue; |
| 534 | } |
| 535 | skip = val >> 4; |
| 536 | val = val & 0xF; |
| 537 | if (!val) |
| 538 | return -1; |
| 539 | pos += skip; |
| 540 | if (pos >= 64) |
| 541 | return -1; |
| 542 | |
| 543 | sign = rac_get_model2_sym(c, &bc->sign_model); |
| 544 | if (val > 1) { |
| 545 | val--; |
| 546 | val = (1 << val) + rac_get_bits(c, val); |
| 547 | } |
| 548 | if (!sign) |
| 549 | val = -val; |
| 550 | |
| 551 | zz_pos = ff_zigzag_direct[pos]; |
| 552 | block[zz_pos] = val * bc->qmat[zz_pos]; |
| 553 | pos++; |
| 554 | } |
| 555 | |
| 556 | return pos == 64 ? 0 : -1; |
| 557 | } |
| 558 | |
| 559 | static void decode_dct_block(RangeCoder *c, DCTBlockCoder *bc, |
| 560 | uint8_t *dst, int stride, int block_size, |
| 561 | int *block, int mb_x, int mb_y) |
| 562 | { |
| 563 | int i, j; |
| 564 | int bx, by; |
| 565 | int nblocks = block_size >> 3; |
| 566 | |
| 567 | bx = mb_x * nblocks; |
| 568 | by = mb_y * nblocks; |
| 569 | |
| 570 | for (j = 0; j < nblocks; j++) { |
| 571 | for (i = 0; i < nblocks; i++) { |
| 572 | if (decode_dct(c, bc, block, bx + i, by + j)) { |
| 573 | c->got_error = 1; |
| 574 | return; |
| 575 | } |
| 576 | ff_mss34_dct_put(dst + i * 8, stride, block); |
| 577 | } |
| 578 | dst += 8 * stride; |
| 579 | } |
| 580 | } |
| 581 | |
| 582 | static void decode_haar_block(RangeCoder *c, HaarBlockCoder *hc, |
| 583 | uint8_t *dst, int stride, int block_size, |
| 584 | int *block) |
| 585 | { |
| 586 | const int hsize = block_size >> 1; |
| 587 | int A, B, C, D, t1, t2, t3, t4; |
| 588 | int i, j; |
| 589 | |
| 590 | for (j = 0; j < block_size; j++) { |
| 591 | for (i = 0; i < block_size; i++) { |
| 592 | if (i < hsize && j < hsize) |
| 593 | block[i] = rac_get_model256_sym(c, &hc->coef_model); |
| 594 | else |
| 595 | block[i] = decode_coeff(c, &hc->coef_hi_model); |
| 596 | block[i] *= hc->scale; |
| 597 | } |
| 598 | block += block_size; |
| 599 | } |
| 600 | block -= block_size * block_size; |
| 601 | |
| 602 | for (j = 0; j < hsize; j++) { |
| 603 | for (i = 0; i < hsize; i++) { |
| 604 | A = block[i]; |
| 605 | B = block[i + hsize]; |
| 606 | C = block[i + hsize * block_size]; |
| 607 | D = block[i + hsize * block_size + hsize]; |
| 608 | |
| 609 | t1 = A - B; |
| 610 | t2 = C - D; |
| 611 | t3 = A + B; |
| 612 | t4 = C + D; |
| 613 | dst[i * 2] = av_clip_uint8(t1 - t2); |
| 614 | dst[i * 2 + stride] = av_clip_uint8(t1 + t2); |
| 615 | dst[i * 2 + 1] = av_clip_uint8(t3 - t4); |
| 616 | dst[i * 2 + 1 + stride] = av_clip_uint8(t3 + t4); |
| 617 | } |
| 618 | block += block_size; |
| 619 | dst += stride * 2; |
| 620 | } |
| 621 | } |
| 622 | |
| 623 | static void reset_coders(MSS3Context *ctx, int quality) |
| 624 | { |
| 625 | int i, j; |
| 626 | |
| 627 | for (i = 0; i < 3; i++) { |
| 628 | ctx->btype[i].last_type = SKIP_BLOCK; |
| 629 | for (j = 0; j < 5; j++) |
| 630 | model_reset(&ctx->btype[i].bt_model[j]); |
| 631 | ctx->fill_coder[i].fill_val = 0; |
| 632 | model_reset(&ctx->fill_coder[i].coef_model); |
| 633 | model256_reset(&ctx->image_coder[i].esc_model); |
| 634 | model256_reset(&ctx->image_coder[i].vec_entry_model); |
| 635 | model_reset(&ctx->image_coder[i].vec_size_model); |
| 636 | for (j = 0; j < 125; j++) |
| 637 | model_reset(&ctx->image_coder[i].vq_model[j]); |
| 638 | if (ctx->dct_coder[i].quality != quality) { |
| 639 | ctx->dct_coder[i].quality = quality; |
| 640 | ff_mss34_gen_quant_mat(ctx->dct_coder[i].qmat, quality, !i); |
| 641 | } |
| 642 | memset(ctx->dct_coder[i].prev_dc, 0, |
| 643 | sizeof(*ctx->dct_coder[i].prev_dc) * |
| 644 | ctx->dct_coder[i].prev_dc_stride * |
| 645 | ctx->dct_coder[i].prev_dc_height); |
| 646 | model_reset(&ctx->dct_coder[i].dc_model); |
| 647 | model2_reset(&ctx->dct_coder[i].sign_model); |
| 648 | model256_reset(&ctx->dct_coder[i].ac_model); |
| 649 | if (ctx->haar_coder[i].quality != quality) { |
| 650 | ctx->haar_coder[i].quality = quality; |
| 651 | ctx->haar_coder[i].scale = 17 - 7 * quality / 50; |
| 652 | } |
| 653 | model_reset(&ctx->haar_coder[i].coef_hi_model); |
| 654 | model256_reset(&ctx->haar_coder[i].coef_model); |
| 655 | } |
| 656 | } |
| 657 | |
| 658 | static av_cold void init_coders(MSS3Context *ctx) |
| 659 | { |
| 660 | int i, j; |
| 661 | |
| 662 | for (i = 0; i < 3; i++) { |
| 663 | for (j = 0; j < 5; j++) |
| 664 | model_init(&ctx->btype[i].bt_model[j], 5); |
| 665 | model_init(&ctx->fill_coder[i].coef_model, 12); |
| 666 | model256_init(&ctx->image_coder[i].esc_model); |
| 667 | model256_init(&ctx->image_coder[i].vec_entry_model); |
| 668 | model_init(&ctx->image_coder[i].vec_size_model, 3); |
| 669 | for (j = 0; j < 125; j++) |
| 670 | model_init(&ctx->image_coder[i].vq_model[j], 5); |
| 671 | model_init(&ctx->dct_coder[i].dc_model, 12); |
| 672 | model256_init(&ctx->dct_coder[i].ac_model); |
| 673 | model_init(&ctx->haar_coder[i].coef_hi_model, 12); |
| 674 | model256_init(&ctx->haar_coder[i].coef_model); |
| 675 | } |
| 676 | } |
| 677 | |
| 678 | static int mss3_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, |
| 679 | AVPacket *avpkt) |
| 680 | { |
| 681 | const uint8_t *buf = avpkt->data; |
| 682 | int buf_size = avpkt->size; |
| 683 | MSS3Context *c = avctx->priv_data; |
| 684 | RangeCoder *acoder = &c->coder; |
| 685 | GetByteContext gb; |
| 686 | uint8_t *dst[3]; |
| 687 | int dec_width, dec_height, dec_x, dec_y, quality, keyframe; |
| 688 | int x, y, i, mb_width, mb_height, blk_size, btype; |
| 689 | int ret; |
| 690 | |
| 691 | if (buf_size < HEADER_SIZE) { |
| 692 | av_log(avctx, AV_LOG_ERROR, |
| 693 | "Frame should have at least %d bytes, got %d instead\n", |
| 694 | HEADER_SIZE, buf_size); |
| 695 | return AVERROR_INVALIDDATA; |
| 696 | } |
| 697 | |
| 698 | bytestream2_init(&gb, buf, buf_size); |
| 699 | keyframe = bytestream2_get_be32(&gb); |
| 700 | if (keyframe & ~0x301) { |
| 701 | av_log(avctx, AV_LOG_ERROR, "Invalid frame type %X\n", keyframe); |
| 702 | return AVERROR_INVALIDDATA; |
| 703 | } |
| 704 | keyframe = !(keyframe & 1); |
| 705 | bytestream2_skip(&gb, 6); |
| 706 | dec_x = bytestream2_get_be16(&gb); |
| 707 | dec_y = bytestream2_get_be16(&gb); |
| 708 | dec_width = bytestream2_get_be16(&gb); |
| 709 | dec_height = bytestream2_get_be16(&gb); |
| 710 | |
| 711 | if (dec_x + dec_width > avctx->width || |
| 712 | dec_y + dec_height > avctx->height || |
| 713 | (dec_width | dec_height) & 0xF) { |
| 714 | av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d +%d,%d\n", |
| 715 | dec_width, dec_height, dec_x, dec_y); |
| 716 | return AVERROR_INVALIDDATA; |
| 717 | } |
| 718 | bytestream2_skip(&gb, 4); |
| 719 | quality = bytestream2_get_byte(&gb); |
| 720 | if (quality < 1 || quality > 100) { |
| 721 | av_log(avctx, AV_LOG_ERROR, "Invalid quality setting %d\n", quality); |
| 722 | return AVERROR_INVALIDDATA; |
| 723 | } |
| 724 | bytestream2_skip(&gb, 4); |
| 725 | |
| 726 | if (keyframe && !bytestream2_get_bytes_left(&gb)) { |
| 727 | av_log(avctx, AV_LOG_ERROR, "Keyframe without data found\n"); |
| 728 | return AVERROR_INVALIDDATA; |
| 729 | } |
| 730 | if (!keyframe && c->got_error) |
| 731 | return buf_size; |
| 732 | c->got_error = 0; |
| 733 | |
| 734 | if ((ret = ff_reget_buffer(avctx, c->pic)) < 0) |
| 735 | return ret; |
| 736 | c->pic->key_frame = keyframe; |
| 737 | c->pic->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P; |
| 738 | if (!bytestream2_get_bytes_left(&gb)) { |
| 739 | if ((ret = av_frame_ref(data, c->pic)) < 0) |
| 740 | return ret; |
| 741 | *got_frame = 1; |
| 742 | |
| 743 | return buf_size; |
| 744 | } |
| 745 | |
| 746 | reset_coders(c, quality); |
| 747 | |
| 748 | rac_init(acoder, buf + HEADER_SIZE, buf_size - HEADER_SIZE); |
| 749 | |
| 750 | mb_width = dec_width >> 4; |
| 751 | mb_height = dec_height >> 4; |
| 752 | dst[0] = c->pic->data[0] + dec_x + dec_y * c->pic->linesize[0]; |
| 753 | dst[1] = c->pic->data[1] + dec_x / 2 + (dec_y / 2) * c->pic->linesize[1]; |
| 754 | dst[2] = c->pic->data[2] + dec_x / 2 + (dec_y / 2) * c->pic->linesize[2]; |
| 755 | for (y = 0; y < mb_height; y++) { |
| 756 | for (x = 0; x < mb_width; x++) { |
| 757 | for (i = 0; i < 3; i++) { |
| 758 | blk_size = 8 << !i; |
| 759 | |
| 760 | btype = decode_block_type(acoder, c->btype + i); |
| 761 | switch (btype) { |
| 762 | case FILL_BLOCK: |
| 763 | decode_fill_block(acoder, c->fill_coder + i, |
| 764 | dst[i] + x * blk_size, |
| 765 | c->pic->linesize[i], blk_size); |
| 766 | break; |
| 767 | case IMAGE_BLOCK: |
| 768 | decode_image_block(acoder, c->image_coder + i, |
| 769 | dst[i] + x * blk_size, |
| 770 | c->pic->linesize[i], blk_size); |
| 771 | break; |
| 772 | case DCT_BLOCK: |
| 773 | decode_dct_block(acoder, c->dct_coder + i, |
| 774 | dst[i] + x * blk_size, |
| 775 | c->pic->linesize[i], blk_size, |
| 776 | c->dctblock, x, y); |
| 777 | break; |
| 778 | case HAAR_BLOCK: |
| 779 | decode_haar_block(acoder, c->haar_coder + i, |
| 780 | dst[i] + x * blk_size, |
| 781 | c->pic->linesize[i], blk_size, |
| 782 | c->hblock); |
| 783 | break; |
| 784 | } |
| 785 | if (c->got_error || acoder->got_error) { |
| 786 | av_log(avctx, AV_LOG_ERROR, "Error decoding block %d,%d\n", |
| 787 | x, y); |
| 788 | c->got_error = 1; |
| 789 | return AVERROR_INVALIDDATA; |
| 790 | } |
| 791 | } |
| 792 | } |
| 793 | dst[0] += c->pic->linesize[0] * 16; |
| 794 | dst[1] += c->pic->linesize[1] * 8; |
| 795 | dst[2] += c->pic->linesize[2] * 8; |
| 796 | } |
| 797 | |
| 798 | if ((ret = av_frame_ref(data, c->pic)) < 0) |
| 799 | return ret; |
| 800 | |
| 801 | *got_frame = 1; |
| 802 | |
| 803 | return buf_size; |
| 804 | } |
| 805 | |
| 806 | static av_cold int mss3_decode_end(AVCodecContext *avctx) |
| 807 | { |
| 808 | MSS3Context * const c = avctx->priv_data; |
| 809 | int i; |
| 810 | |
| 811 | av_frame_free(&c->pic); |
| 812 | for (i = 0; i < 3; i++) |
| 813 | av_freep(&c->dct_coder[i].prev_dc); |
| 814 | |
| 815 | return 0; |
| 816 | } |
| 817 | |
| 818 | static av_cold int mss3_decode_init(AVCodecContext *avctx) |
| 819 | { |
| 820 | MSS3Context * const c = avctx->priv_data; |
| 821 | int i; |
| 822 | |
| 823 | c->avctx = avctx; |
| 824 | |
| 825 | if ((avctx->width & 0xF) || (avctx->height & 0xF)) { |
| 826 | av_log(avctx, AV_LOG_ERROR, |
| 827 | "Image dimensions should be a multiple of 16.\n"); |
| 828 | return AVERROR_INVALIDDATA; |
| 829 | } |
| 830 | |
| 831 | c->got_error = 0; |
| 832 | for (i = 0; i < 3; i++) { |
| 833 | int b_width = avctx->width >> (2 + !!i); |
| 834 | int b_height = avctx->height >> (2 + !!i); |
| 835 | c->dct_coder[i].prev_dc_stride = b_width; |
| 836 | c->dct_coder[i].prev_dc_height = b_height; |
| 837 | c->dct_coder[i].prev_dc = av_malloc(sizeof(*c->dct_coder[i].prev_dc) * |
| 838 | b_width * b_height); |
| 839 | if (!c->dct_coder[i].prev_dc) { |
| 840 | av_log(avctx, AV_LOG_ERROR, "Cannot allocate buffer\n"); |
| 841 | av_frame_free(&c->pic); |
| 842 | while (i >= 0) { |
| 843 | av_freep(&c->dct_coder[i].prev_dc); |
| 844 | i--; |
| 845 | } |
| 846 | return AVERROR(ENOMEM); |
| 847 | } |
| 848 | } |
| 849 | |
| 850 | c->pic = av_frame_alloc(); |
| 851 | if (!c->pic) { |
| 852 | mss3_decode_end(avctx); |
| 853 | return AVERROR(ENOMEM); |
| 854 | } |
| 855 | |
| 856 | avctx->pix_fmt = AV_PIX_FMT_YUV420P; |
| 857 | |
| 858 | init_coders(c); |
| 859 | |
| 860 | return 0; |
| 861 | } |
| 862 | |
| 863 | AVCodec ff_msa1_decoder = { |
| 864 | .name = "msa1", |
| 865 | .long_name = NULL_IF_CONFIG_SMALL("MS ATC Screen"), |
| 866 | .type = AVMEDIA_TYPE_VIDEO, |
| 867 | .id = AV_CODEC_ID_MSA1, |
| 868 | .priv_data_size = sizeof(MSS3Context), |
| 869 | .init = mss3_decode_init, |
| 870 | .close = mss3_decode_end, |
| 871 | .decode = mss3_decode_frame, |
| 872 | .capabilities = CODEC_CAP_DR1, |
| 873 | }; |