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 "codec_internal.h" 30#include "internal.h" 31#include "mathops.h" 32#include "mss34dsp.h" 33 34#define HEADER_SIZE 27 35 36#define MODEL2_SCALE 13 37#define MODEL_SCALE 15 38#define MODEL256_SEC_SCALE 9 39 40typedef struct Model2 { 41 int upd_val, till_rescale; 42 unsigned zero_freq, zero_weight; 43 unsigned total_freq, total_weight; 44} Model2; 45 46typedef struct Model { 47 int weights[16], freqs[16]; 48 int num_syms; 49 int tot_weight; 50 int upd_val, max_upd_val, till_rescale; 51} Model; 52 53typedef struct Model256 { 54 int weights[256], freqs[256]; 55 int tot_weight; 56 int secondary[68]; 57 int sec_size; 58 int upd_val, max_upd_val, till_rescale; 59} Model256; 60 61#define RAC_BOTTOM 0x01000000 62typedef struct RangeCoder { 63 const uint8_t *src, *src_end; 64 65 uint32_t range, low; 66 int got_error; 67} RangeCoder; 68 69enum BlockType { 70 FILL_BLOCK = 0, 71 IMAGE_BLOCK, 72 DCT_BLOCK, 73 HAAR_BLOCK, 74 SKIP_BLOCK 75}; 76 77typedef struct BlockTypeContext { 78 int last_type; 79 Model bt_model[5]; 80} BlockTypeContext; 81 82typedef struct FillBlockCoder { 83 int fill_val; 84 Model coef_model; 85} FillBlockCoder; 86 87typedef struct ImageBlockCoder { 88 Model256 esc_model, vec_entry_model; 89 Model vec_size_model; 90 Model vq_model[125]; 91} ImageBlockCoder; 92 93typedef struct DCTBlockCoder { 94 int *prev_dc; 95 ptrdiff_t prev_dc_stride; 96 int prev_dc_height; 97 int quality; 98 uint16_t qmat[64]; 99 Model dc_model; 100 Model2 sign_model; 101 Model256 ac_model; 102} DCTBlockCoder; 103 104typedef struct HaarBlockCoder { 105 int quality, scale; 106 Model256 coef_model; 107 Model coef_hi_model; 108} HaarBlockCoder; 109 110typedef struct MSS3Context { 111 AVCodecContext *avctx; 112 AVFrame *pic; 113 114 int got_error; 115 RangeCoder coder; 116 BlockTypeContext btype[3]; 117 FillBlockCoder fill_coder[3]; 118 ImageBlockCoder image_coder[3]; 119 DCTBlockCoder dct_coder[3]; 120 HaarBlockCoder haar_coder[3]; 121 122 int dctblock[64]; 123 int hblock[16 * 16]; 124} MSS3Context; 125 126 127static void model2_reset(Model2 *m) 128{ 129 m->zero_weight = 1; 130 m->total_weight = 2; 131 m->zero_freq = 0x1000; 132 m->total_freq = 0x2000; 133 m->upd_val = 4; 134 m->till_rescale = 4; 135} 136 137static void model2_update(Model2 *m, int bit) 138{ 139 unsigned scale; 140 141 if (!bit) 142 m->zero_weight++; 143 m->till_rescale--; 144 if (m->till_rescale) 145 return; 146 147 m->total_weight += m->upd_val; 148 if (m->total_weight > 0x2000) { 149 m->total_weight = (m->total_weight + 1) >> 1; 150 m->zero_weight = (m->zero_weight + 1) >> 1; 151 if (m->total_weight == m->zero_weight) 152 m->total_weight = m->zero_weight + 1; 153 } 154 m->upd_val = m->upd_val * 5 >> 2; 155 if (m->upd_val > 64) 156 m->upd_val = 64; 157 scale = 0x80000000u / m->total_weight; 158 m->zero_freq = m->zero_weight * scale >> 18; 159 m->total_freq = m->total_weight * scale >> 18; 160 m->till_rescale = m->upd_val; 161} 162 163static void model_update(Model *m, int val) 164{ 165 int i, sum = 0; 166 unsigned scale; 167 168 m->weights[val]++; 169 m->till_rescale--; 170 if (m->till_rescale) 171 return; 172 m->tot_weight += m->upd_val; 173 174 if (m->tot_weight > 0x8000) { 175 m->tot_weight = 0; 176 for (i = 0; i < m->num_syms; i++) { 177 m->weights[i] = (m->weights[i] + 1) >> 1; 178 m->tot_weight += m->weights[i]; 179 } 180 } 181 scale = 0x80000000u / m->tot_weight; 182 for (i = 0; i < m->num_syms; i++) { 183 m->freqs[i] = sum * scale >> 16; 184 sum += m->weights[i]; 185 } 186 187 m->upd_val = m->upd_val * 5 >> 2; 188 if (m->upd_val > m->max_upd_val) 189 m->upd_val = m->max_upd_val; 190 m->till_rescale = m->upd_val; 191} 192 193static void model_reset(Model *m) 194{ 195 int i; 196 197 m->tot_weight = 0; 198 for (i = 0; i < m->num_syms - 1; i++) 199 m->weights[i] = 1; 200 m->weights[m->num_syms - 1] = 0; 201 202 m->upd_val = m->num_syms; 203 m->till_rescale = 1; 204 model_update(m, m->num_syms - 1); 205 m->till_rescale = 206 m->upd_val = (m->num_syms + 6) >> 1; 207} 208 209static av_cold void model_init(Model *m, int num_syms) 210{ 211 m->num_syms = num_syms; 212 m->max_upd_val = 8 * num_syms + 48; 213 214 model_reset(m); 215} 216 217static void model256_update(Model256 *m, int val) 218{ 219 int i, sum = 0; 220 unsigned scale; 221 int send, sidx = 1; 222 223 m->weights[val]++; 224 m->till_rescale--; 225 if (m->till_rescale) 226 return; 227 m->tot_weight += m->upd_val; 228 229 if (m->tot_weight > 0x8000) { 230 m->tot_weight = 0; 231 for (i = 0; i < 256; i++) { 232 m->weights[i] = (m->weights[i] + 1) >> 1; 233 m->tot_weight += m->weights[i]; 234 } 235 } 236 scale = 0x80000000u / m->tot_weight; 237 m->secondary[0] = 0; 238 for (i = 0; i < 256; i++) { 239 m->freqs[i] = sum * scale >> 16; 240 sum += m->weights[i]; 241 send = m->freqs[i] >> MODEL256_SEC_SCALE; 242 while (sidx <= send) 243 m->secondary[sidx++] = i - 1; 244 } 245 while (sidx < m->sec_size) 246 m->secondary[sidx++] = 255; 247 248 m->upd_val = m->upd_val * 5 >> 2; 249 if (m->upd_val > m->max_upd_val) 250 m->upd_val = m->max_upd_val; 251 m->till_rescale = m->upd_val; 252} 253 254static void model256_reset(Model256 *m) 255{ 256 int i; 257 258 for (i = 0; i < 255; i++) 259 m->weights[i] = 1; 260 m->weights[255] = 0; 261 262 m->tot_weight = 0; 263 m->upd_val = 256; 264 m->till_rescale = 1; 265 model256_update(m, 255); 266 m->till_rescale = 267 m->upd_val = (256 + 6) >> 1; 268} 269 270static av_cold void model256_init(Model256 *m) 271{ 272 m->max_upd_val = 8 * 256 + 48; 273 m->sec_size = (1 << 6) + 2; 274 275 model256_reset(m); 276} 277 278static void rac_init(RangeCoder *c, const uint8_t *src, int size) 279{ 280 int i; 281 282 c->src = src; 283 c->src_end = src + size; 284 c->low = 0; 285 for (i = 0; i < FFMIN(size, 4); i++) 286 c->low = (c->low << 8) | *c->src++; 287 c->range = 0xFFFFFFFF; 288 c->got_error = 0; 289} 290 291static void rac_normalise(RangeCoder *c) 292{ 293 for (;;) { 294 c->range <<= 8; 295 c->low <<= 8; 296 if (c->src < c->src_end) { 297 c->low |= *c->src++; 298 } else if (!c->low) { 299 c->got_error = 1; 300 c->low = 1; 301 } 302 if (c->low > c->range) { 303 c->got_error = 1; 304 c->low = 1; 305 } 306 if (c->range >= RAC_BOTTOM) 307 return; 308 } 309} 310 311static int rac_get_bit(RangeCoder *c) 312{ 313 int bit; 314 315 c->range >>= 1; 316 317 bit = (c->range <= c->low); 318 if (bit) 319 c->low -= c->range; 320 321 if (c->range < RAC_BOTTOM) 322 rac_normalise(c); 323 324 return bit; 325} 326 327static int rac_get_bits(RangeCoder *c, int nbits) 328{ 329 int val; 330 331 c->range >>= nbits; 332 val = c->low / c->range; 333 c->low -= c->range * val; 334 335 if (c->range < RAC_BOTTOM) 336 rac_normalise(c); 337 338 return val; 339} 340 341static int rac_get_model2_sym(RangeCoder *c, Model2 *m) 342{ 343 int bit, helper; 344 345 helper = m->zero_freq * (c->range >> MODEL2_SCALE); 346 bit = (c->low >= helper); 347 if (bit) { 348 c->low -= helper; 349 c->range -= helper; 350 } else { 351 c->range = helper; 352 } 353 354 if (c->range < RAC_BOTTOM) 355 rac_normalise(c); 356 357 model2_update(m, bit); 358 359 return bit; 360} 361 362static int rac_get_model_sym(RangeCoder *c, Model *m) 363{ 364 int val; 365 int end, end2; 366 unsigned prob, prob2, helper; 367 368 prob = 0; 369 prob2 = c->range; 370 c->range >>= MODEL_SCALE; 371 val = 0; 372 end = m->num_syms >> 1; 373 end2 = m->num_syms; 374 do { 375 helper = m->freqs[end] * c->range; 376 if (helper <= c->low) { 377 val = end; 378 prob = helper; 379 } else { 380 end2 = end; 381 prob2 = helper; 382 } 383 end = (end2 + val) >> 1; 384 } while (end != val); 385 c->low -= prob; 386 c->range = prob2 - prob; 387 if (c->range < RAC_BOTTOM) 388 rac_normalise(c); 389 390 model_update(m, val); 391 392 return val; 393} 394 395static int rac_get_model256_sym(RangeCoder *c, Model256 *m) 396{ 397 int val; 398 int start, end; 399 int ssym; 400 unsigned prob, prob2, helper; 401 402 prob2 = c->range; 403 c->range >>= MODEL_SCALE; 404 405 helper = c->low / c->range; 406 ssym = helper >> MODEL256_SEC_SCALE; 407 val = m->secondary[ssym]; 408 409 end = start = m->secondary[ssym + 1] + 1; 410 while (end > val + 1) { 411 ssym = (end + val) >> 1; 412 if (m->freqs[ssym] <= helper) { 413 end = start; 414 val = ssym; 415 } else { 416 end = (end + val) >> 1; 417 start = ssym; 418 } 419 } 420 prob = m->freqs[val] * c->range; 421 if (val != 255) 422 prob2 = m->freqs[val + 1] * c->range; 423 424 c->low -= prob; 425 c->range = prob2 - prob; 426 if (c->range < RAC_BOTTOM) 427 rac_normalise(c); 428 429 model256_update(m, val); 430 431 return val; 432} 433 434static int decode_block_type(RangeCoder *c, BlockTypeContext *bt) 435{ 436 bt->last_type = rac_get_model_sym(c, &bt->bt_model[bt->last_type]); 437 438 return bt->last_type; 439} 440 441static int decode_coeff(RangeCoder *c, Model *m) 442{ 443 int val, sign; 444 445 val = rac_get_model_sym(c, m); 446 if (val) { 447 sign = rac_get_bit(c); 448 if (val > 1) { 449 val--; 450 val = (1 << val) + rac_get_bits(c, val); 451 } 452 if (!sign) 453 val = -val; 454 } 455 456 return val; 457} 458 459static void decode_fill_block(RangeCoder *c, FillBlockCoder *fc, 460 uint8_t *dst, ptrdiff_t stride, int block_size) 461{ 462 int i; 463 464 fc->fill_val += decode_coeff(c, &fc->coef_model); 465 466 for (i = 0; i < block_size; i++, dst += stride) 467 memset(dst, fc->fill_val, block_size); 468} 469 470static void decode_image_block(RangeCoder *c, ImageBlockCoder *ic, 471 uint8_t *dst, ptrdiff_t stride, int block_size) 472{ 473 int i, j; 474 int vec_size; 475 int vec[4]; 476 int prev_line[16]; 477 int A, B, C; 478 479 vec_size = rac_get_model_sym(c, &ic->vec_size_model) + 2; 480 for (i = 0; i < vec_size; i++) 481 vec[i] = rac_get_model256_sym(c, &ic->vec_entry_model); 482 for (; i < 4; i++) 483 vec[i] = 0; 484 memset(prev_line, 0, sizeof(prev_line)); 485 486 for (j = 0; j < block_size; j++) { 487 A = 0; 488 B = 0; 489 for (i = 0; i < block_size; i++) { 490 C = B; 491 B = prev_line[i]; 492 A = rac_get_model_sym(c, &ic->vq_model[A + B * 5 + C * 25]); 493 494 prev_line[i] = A; 495 if (A < 4) 496 dst[i] = vec[A]; 497 else 498 dst[i] = rac_get_model256_sym(c, &ic->esc_model); 499 } 500 dst += stride; 501 } 502} 503 504static int decode_dct(RangeCoder *c, DCTBlockCoder *bc, int *block, 505 int bx, int by) 506{ 507 int skip, val, sign, pos = 1, zz_pos, dc; 508 int blk_pos = bx + by * bc->prev_dc_stride; 509 510 memset(block, 0, sizeof(*block) * 64); 511 512 dc = decode_coeff(c, &bc->dc_model); 513 if (by) { 514 if (bx) { 515 int l, tl, t; 516 517 l = bc->prev_dc[blk_pos - 1]; 518 tl = bc->prev_dc[blk_pos - 1 - bc->prev_dc_stride]; 519 t = bc->prev_dc[blk_pos - bc->prev_dc_stride]; 520 521 if (FFABS(t - tl) <= FFABS(l - tl)) 522 dc += l; 523 else 524 dc += t; 525 } else { 526 dc += bc->prev_dc[blk_pos - bc->prev_dc_stride]; 527 } 528 } else if (bx) { 529 dc += bc->prev_dc[bx - 1]; 530 } 531 bc->prev_dc[blk_pos] = dc; 532 block[0] = dc * bc->qmat[0]; 533 534 while (pos < 64) { 535 val = rac_get_model256_sym(c, &bc->ac_model); 536 if (!val) 537 return 0; 538 if (val == 0xF0) { 539 pos += 16; 540 continue; 541 } 542 skip = val >> 4; 543 val = val & 0xF; 544 if (!val) 545 return -1; 546 pos += skip; 547 if (pos >= 64) 548 return -1; 549 550 sign = rac_get_model2_sym(c, &bc->sign_model); 551 if (val > 1) { 552 val--; 553 val = (1 << val) + rac_get_bits(c, val); 554 } 555 if (!sign) 556 val = -val; 557 558 zz_pos = ff_zigzag_direct[pos]; 559 block[zz_pos] = val * bc->qmat[zz_pos]; 560 pos++; 561 } 562 563 return pos == 64 ? 0 : -1; 564} 565 566static void decode_dct_block(RangeCoder *c, DCTBlockCoder *bc, 567 uint8_t *dst, ptrdiff_t stride, int block_size, 568 int *block, int mb_x, int mb_y) 569{ 570 int i, j; 571 int bx, by; 572 int nblocks = block_size >> 3; 573 574 bx = mb_x * nblocks; 575 by = mb_y * nblocks; 576 577 for (j = 0; j < nblocks; j++) { 578 for (i = 0; i < nblocks; i++) { 579 if (decode_dct(c, bc, block, bx + i, by + j)) { 580 c->got_error = 1; 581 return; 582 } 583 ff_mss34_dct_put(dst + i * 8, stride, block); 584 } 585 dst += 8 * stride; 586 } 587} 588 589static void decode_haar_block(RangeCoder *c, HaarBlockCoder *hc, 590 uint8_t *dst, ptrdiff_t stride, 591 int block_size, int *block) 592{ 593 const int hsize = block_size >> 1; 594 int A, B, C, D, t1, t2, t3, t4; 595 int i, j; 596 597 for (j = 0; j < block_size; j++) { 598 for (i = 0; i < block_size; i++) { 599 if (i < hsize && j < hsize) 600 block[i] = rac_get_model256_sym(c, &hc->coef_model); 601 else 602 block[i] = decode_coeff(c, &hc->coef_hi_model); 603 block[i] *= hc->scale; 604 } 605 block += block_size; 606 } 607 block -= block_size * block_size; 608 609 for (j = 0; j < hsize; j++) { 610 for (i = 0; i < hsize; i++) { 611 A = block[i]; 612 B = block[i + hsize]; 613 C = block[i + hsize * block_size]; 614 D = block[i + hsize * block_size + hsize]; 615 616 t1 = A - B; 617 t2 = C - D; 618 t3 = A + B; 619 t4 = C + D; 620 dst[i * 2] = av_clip_uint8(t1 - t2); 621 dst[i * 2 + stride] = av_clip_uint8(t1 + t2); 622 dst[i * 2 + 1] = av_clip_uint8(t3 - t4); 623 dst[i * 2 + 1 + stride] = av_clip_uint8(t3 + t4); 624 } 625 block += block_size; 626 dst += stride * 2; 627 } 628} 629 630static void reset_coders(MSS3Context *ctx, int quality) 631{ 632 int i, j; 633 634 for (i = 0; i < 3; i++) { 635 ctx->btype[i].last_type = SKIP_BLOCK; 636 for (j = 0; j < 5; j++) 637 model_reset(&ctx->btype[i].bt_model[j]); 638 ctx->fill_coder[i].fill_val = 0; 639 model_reset(&ctx->fill_coder[i].coef_model); 640 model256_reset(&ctx->image_coder[i].esc_model); 641 model256_reset(&ctx->image_coder[i].vec_entry_model); 642 model_reset(&ctx->image_coder[i].vec_size_model); 643 for (j = 0; j < 125; j++) 644 model_reset(&ctx->image_coder[i].vq_model[j]); 645 if (ctx->dct_coder[i].quality != quality) { 646 ctx->dct_coder[i].quality = quality; 647 ff_mss34_gen_quant_mat(ctx->dct_coder[i].qmat, quality, !i); 648 } 649 memset(ctx->dct_coder[i].prev_dc, 0, 650 sizeof(*ctx->dct_coder[i].prev_dc) * 651 ctx->dct_coder[i].prev_dc_stride * 652 ctx->dct_coder[i].prev_dc_height); 653 model_reset(&ctx->dct_coder[i].dc_model); 654 model2_reset(&ctx->dct_coder[i].sign_model); 655 model256_reset(&ctx->dct_coder[i].ac_model); 656 if (ctx->haar_coder[i].quality != quality) { 657 ctx->haar_coder[i].quality = quality; 658 ctx->haar_coder[i].scale = 17 - 7 * quality / 50; 659 } 660 model_reset(&ctx->haar_coder[i].coef_hi_model); 661 model256_reset(&ctx->haar_coder[i].coef_model); 662 } 663} 664 665static av_cold void init_coders(MSS3Context *ctx) 666{ 667 int i, j; 668 669 for (i = 0; i < 3; i++) { 670 for (j = 0; j < 5; j++) 671 model_init(&ctx->btype[i].bt_model[j], 5); 672 model_init(&ctx->fill_coder[i].coef_model, 12); 673 model256_init(&ctx->image_coder[i].esc_model); 674 model256_init(&ctx->image_coder[i].vec_entry_model); 675 model_init(&ctx->image_coder[i].vec_size_model, 3); 676 for (j = 0; j < 125; j++) 677 model_init(&ctx->image_coder[i].vq_model[j], 5); 678 model_init(&ctx->dct_coder[i].dc_model, 12); 679 model256_init(&ctx->dct_coder[i].ac_model); 680 model_init(&ctx->haar_coder[i].coef_hi_model, 12); 681 model256_init(&ctx->haar_coder[i].coef_model); 682 } 683} 684 685static int mss3_decode_frame(AVCodecContext *avctx, AVFrame *rframe, 686 int *got_frame, AVPacket *avpkt) 687{ 688 const uint8_t *buf = avpkt->data; 689 int buf_size = avpkt->size; 690 MSS3Context *c = avctx->priv_data; 691 RangeCoder *acoder = &c->coder; 692 GetByteContext gb; 693 uint8_t *dst[3]; 694 int dec_width, dec_height, dec_x, dec_y, quality, keyframe; 695 int x, y, i, mb_width, mb_height, blk_size, btype; 696 int ret; 697 698 if (buf_size < HEADER_SIZE) { 699 av_log(avctx, AV_LOG_ERROR, 700 "Frame should have at least %d bytes, got %d instead\n", 701 HEADER_SIZE, buf_size); 702 return AVERROR_INVALIDDATA; 703 } 704 705 bytestream2_init(&gb, buf, buf_size); 706 keyframe = bytestream2_get_be32(&gb); 707 if (keyframe & ~0x301) { 708 av_log(avctx, AV_LOG_ERROR, "Invalid frame type %X\n", keyframe); 709 return AVERROR_INVALIDDATA; 710 } 711 keyframe = !(keyframe & 1); 712 bytestream2_skip(&gb, 6); 713 dec_x = bytestream2_get_be16(&gb); 714 dec_y = bytestream2_get_be16(&gb); 715 dec_width = bytestream2_get_be16(&gb); 716 dec_height = bytestream2_get_be16(&gb); 717 718 if (dec_x + dec_width > avctx->width || 719 dec_y + dec_height > avctx->height || 720 (dec_width | dec_height) & 0xF) { 721 av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d +%d,%d\n", 722 dec_width, dec_height, dec_x, dec_y); 723 return AVERROR_INVALIDDATA; 724 } 725 bytestream2_skip(&gb, 4); 726 quality = bytestream2_get_byte(&gb); 727 if (quality < 1 || quality > 100) { 728 av_log(avctx, AV_LOG_ERROR, "Invalid quality setting %d\n", quality); 729 return AVERROR_INVALIDDATA; 730 } 731 bytestream2_skip(&gb, 4); 732 733 if (keyframe && !bytestream2_get_bytes_left(&gb)) { 734 av_log(avctx, AV_LOG_ERROR, "Keyframe without data found\n"); 735 return AVERROR_INVALIDDATA; 736 } 737 if (!keyframe && c->got_error) 738 return buf_size; 739 c->got_error = 0; 740 741 if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0) 742 return ret; 743 c->pic->key_frame = keyframe; 744 c->pic->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P; 745 if (!bytestream2_get_bytes_left(&gb)) { 746 if ((ret = av_frame_ref(rframe, c->pic)) < 0) 747 return ret; 748 *got_frame = 1; 749 750 return buf_size; 751 } 752 753 reset_coders(c, quality); 754 755 rac_init(acoder, buf + HEADER_SIZE, buf_size - HEADER_SIZE); 756 757 mb_width = dec_width >> 4; 758 mb_height = dec_height >> 4; 759 dst[0] = c->pic->data[0] + dec_x + dec_y * c->pic->linesize[0]; 760 dst[1] = c->pic->data[1] + dec_x / 2 + (dec_y / 2) * c->pic->linesize[1]; 761 dst[2] = c->pic->data[2] + dec_x / 2 + (dec_y / 2) * c->pic->linesize[2]; 762 for (y = 0; y < mb_height; y++) { 763 for (x = 0; x < mb_width; x++) { 764 for (i = 0; i < 3; i++) { 765 blk_size = 8 << !i; 766 767 btype = decode_block_type(acoder, c->btype + i); 768 switch (btype) { 769 case FILL_BLOCK: 770 decode_fill_block(acoder, c->fill_coder + i, 771 dst[i] + x * blk_size, 772 c->pic->linesize[i], blk_size); 773 break; 774 case IMAGE_BLOCK: 775 decode_image_block(acoder, c->image_coder + i, 776 dst[i] + x * blk_size, 777 c->pic->linesize[i], blk_size); 778 break; 779 case DCT_BLOCK: 780 decode_dct_block(acoder, c->dct_coder + i, 781 dst[i] + x * blk_size, 782 c->pic->linesize[i], blk_size, 783 c->dctblock, x, y); 784 break; 785 case HAAR_BLOCK: 786 decode_haar_block(acoder, c->haar_coder + i, 787 dst[i] + x * blk_size, 788 c->pic->linesize[i], blk_size, 789 c->hblock); 790 break; 791 } 792 if (c->got_error || acoder->got_error) { 793 av_log(avctx, AV_LOG_ERROR, "Error decoding block %d,%d\n", 794 x, y); 795 c->got_error = 1; 796 return AVERROR_INVALIDDATA; 797 } 798 } 799 } 800 dst[0] += c->pic->linesize[0] * 16; 801 dst[1] += c->pic->linesize[1] * 8; 802 dst[2] += c->pic->linesize[2] * 8; 803 } 804 805 if ((ret = av_frame_ref(rframe, c->pic)) < 0) 806 return ret; 807 808 *got_frame = 1; 809 810 return buf_size; 811} 812 813static av_cold int mss3_decode_end(AVCodecContext *avctx) 814{ 815 MSS3Context * const c = avctx->priv_data; 816 int i; 817 818 av_frame_free(&c->pic); 819 for (i = 0; i < 3; i++) 820 av_freep(&c->dct_coder[i].prev_dc); 821 822 return 0; 823} 824 825static av_cold int mss3_decode_init(AVCodecContext *avctx) 826{ 827 MSS3Context * const c = avctx->priv_data; 828 int i; 829 830 c->avctx = avctx; 831 832 if ((avctx->width & 0xF) || (avctx->height & 0xF)) { 833 av_log(avctx, AV_LOG_ERROR, 834 "Image dimensions should be a multiple of 16.\n"); 835 return AVERROR_INVALIDDATA; 836 } 837 838 c->got_error = 0; 839 for (i = 0; i < 3; i++) { 840 int b_width = avctx->width >> (2 + !!i); 841 int b_height = avctx->height >> (2 + !!i); 842 c->dct_coder[i].prev_dc_stride = b_width; 843 c->dct_coder[i].prev_dc_height = b_height; 844 c->dct_coder[i].prev_dc = av_malloc(sizeof(*c->dct_coder[i].prev_dc) * 845 b_width * b_height); 846 if (!c->dct_coder[i].prev_dc) { 847 av_log(avctx, AV_LOG_ERROR, "Cannot allocate buffer\n"); 848 return AVERROR(ENOMEM); 849 } 850 } 851 852 c->pic = av_frame_alloc(); 853 if (!c->pic) 854 return AVERROR(ENOMEM); 855 856 avctx->pix_fmt = AV_PIX_FMT_YUV420P; 857 858 init_coders(c); 859 860 return 0; 861} 862 863const FFCodec ff_msa1_decoder = { 864 .p.name = "msa1", 865 .p.long_name = NULL_IF_CONFIG_SMALL("MS ATC Screen"), 866 .p.type = AVMEDIA_TYPE_VIDEO, 867 .p.id = AV_CODEC_ID_MSA1, 868 .priv_data_size = sizeof(MSS3Context), 869 .init = mss3_decode_init, 870 .close = mss3_decode_end, 871 FF_CODEC_DECODE_CB(mss3_decode_frame), 872 .p.capabilities = AV_CODEC_CAP_DR1, 873 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP, 874}; 875