1/* 2 * ITU H263 bitstream decoder 3 * Copyright (c) 2000,2001 Fabrice Bellard 4 * H263+ support. 5 * Copyright (c) 2001 Juan J. Sierralta P 6 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at> 7 * 8 * This file is part of FFmpeg. 9 * 10 * FFmpeg is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU Lesser General Public 12 * License as published by the Free Software Foundation; either 13 * version 2.1 of the License, or (at your option) any later version. 14 * 15 * FFmpeg is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 18 * Lesser General Public License for more details. 19 * 20 * You should have received a copy of the GNU Lesser General Public 21 * License along with FFmpeg; if not, write to the Free Software 22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 23 */ 24 25/** 26 * @file 27 * h263 decoder. 28 */ 29 30//#define DEBUG 31#include <limits.h> 32 33#include "dsputil.h" 34#include "avcodec.h" 35#include "mpegvideo.h" 36#include "h263.h" 37#include "mathops.h" 38#include "unary.h" 39#include "flv.h" 40#include "mpeg4video.h" 41 42//#undef NDEBUG 43//#include <assert.h> 44 45// The defines below define the number of bits that are read at once for 46// reading vlc values. Changing these may improve speed and data cache needs 47// be aware though that decreasing them may need the number of stages that is 48// passed to get_vlc* to be increased. 49#define MV_VLC_BITS 9 50#define H263_MBTYPE_B_VLC_BITS 6 51#define CBPC_B_VLC_BITS 3 52 53static const int h263_mb_type_b_map[15]= { 54 MB_TYPE_DIRECT2 | MB_TYPE_L0L1, 55 MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP, 56 MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT, 57 MB_TYPE_L0 | MB_TYPE_16x16, 58 MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_16x16, 59 MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16, 60 MB_TYPE_L1 | MB_TYPE_16x16, 61 MB_TYPE_L1 | MB_TYPE_CBP | MB_TYPE_16x16, 62 MB_TYPE_L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16, 63 MB_TYPE_L0L1 | MB_TYPE_16x16, 64 MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_16x16, 65 MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16, 66 0, //stuffing 67 MB_TYPE_INTRA4x4 | MB_TYPE_CBP, 68 MB_TYPE_INTRA4x4 | MB_TYPE_CBP | MB_TYPE_QUANT, 69}; 70 71void ff_h263_show_pict_info(MpegEncContext *s){ 72 if(s->avctx->debug&FF_DEBUG_PICT_INFO){ 73 av_log(s->avctx, AV_LOG_DEBUG, "qp:%d %c size:%d rnd:%d%s%s%s%s%s%s%s%s%s %d/%d\n", 74 s->qscale, av_get_pict_type_char(s->pict_type), 75 s->gb.size_in_bits, 1-s->no_rounding, 76 s->obmc ? " AP" : "", 77 s->umvplus ? " UMV" : "", 78 s->h263_long_vectors ? " LONG" : "", 79 s->h263_plus ? " +" : "", 80 s->h263_aic ? " AIC" : "", 81 s->alt_inter_vlc ? " AIV" : "", 82 s->modified_quant ? " MQ" : "", 83 s->loop_filter ? " LOOP" : "", 84 s->h263_slice_structured ? " SS" : "", 85 s->avctx->time_base.den, s->avctx->time_base.num 86 ); 87 } 88} 89 90/***********************************************/ 91/* decoding */ 92 93VLC ff_h263_intra_MCBPC_vlc; 94VLC ff_h263_inter_MCBPC_vlc; 95VLC ff_h263_cbpy_vlc; 96static VLC mv_vlc; 97static VLC h263_mbtype_b_vlc; 98static VLC cbpc_b_vlc; 99 100/* init vlcs */ 101 102/* XXX: find a better solution to handle static init */ 103void h263_decode_init_vlc(MpegEncContext *s) 104{ 105 static int done = 0; 106 107 if (!done) { 108 done = 1; 109 110 INIT_VLC_STATIC(&ff_h263_intra_MCBPC_vlc, INTRA_MCBPC_VLC_BITS, 9, 111 ff_h263_intra_MCBPC_bits, 1, 1, 112 ff_h263_intra_MCBPC_code, 1, 1, 72); 113 INIT_VLC_STATIC(&ff_h263_inter_MCBPC_vlc, INTER_MCBPC_VLC_BITS, 28, 114 ff_h263_inter_MCBPC_bits, 1, 1, 115 ff_h263_inter_MCBPC_code, 1, 1, 198); 116 INIT_VLC_STATIC(&ff_h263_cbpy_vlc, CBPY_VLC_BITS, 16, 117 &ff_h263_cbpy_tab[0][1], 2, 1, 118 &ff_h263_cbpy_tab[0][0], 2, 1, 64); 119 INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 33, 120 &mvtab[0][1], 2, 1, 121 &mvtab[0][0], 2, 1, 538); 122 init_rl(&ff_h263_rl_inter, ff_h263_static_rl_table_store[0]); 123 init_rl(&rl_intra_aic, ff_h263_static_rl_table_store[1]); 124 INIT_VLC_RL(ff_h263_rl_inter, 554); 125 INIT_VLC_RL(rl_intra_aic, 554); 126 INIT_VLC_STATIC(&h263_mbtype_b_vlc, H263_MBTYPE_B_VLC_BITS, 15, 127 &h263_mbtype_b_tab[0][1], 2, 1, 128 &h263_mbtype_b_tab[0][0], 2, 1, 80); 129 INIT_VLC_STATIC(&cbpc_b_vlc, CBPC_B_VLC_BITS, 4, 130 &cbpc_b_tab[0][1], 2, 1, 131 &cbpc_b_tab[0][0], 2, 1, 8); 132 } 133} 134 135int ff_h263_decode_mba(MpegEncContext *s) 136{ 137 int i, mb_pos; 138 139 for(i=0; i<6; i++){ 140 if(s->mb_num-1 <= ff_mba_max[i]) break; 141 } 142 mb_pos= get_bits(&s->gb, ff_mba_length[i]); 143 s->mb_x= mb_pos % s->mb_width; 144 s->mb_y= mb_pos / s->mb_width; 145 146 return mb_pos; 147} 148 149/** 150 * decodes the group of blocks header or slice header. 151 * @return <0 if an error occurred 152 */ 153static int h263_decode_gob_header(MpegEncContext *s) 154{ 155 unsigned int val, gfid, gob_number; 156 int left; 157 158 /* Check for GOB Start Code */ 159 val = show_bits(&s->gb, 16); 160 if(val) 161 return -1; 162 163 /* We have a GBSC probably with GSTUFF */ 164 skip_bits(&s->gb, 16); /* Drop the zeros */ 165 left= get_bits_left(&s->gb); 166 //MN: we must check the bits left or we might end in a infinite loop (or segfault) 167 for(;left>13; left--){ 168 if(get_bits1(&s->gb)) break; /* Seek the '1' bit */ 169 } 170 if(left<=13) 171 return -1; 172 173 if(s->h263_slice_structured){ 174 if(get_bits1(&s->gb)==0) 175 return -1; 176 177 ff_h263_decode_mba(s); 178 179 if(s->mb_num > 1583) 180 if(get_bits1(&s->gb)==0) 181 return -1; 182 183 s->qscale = get_bits(&s->gb, 5); /* SQUANT */ 184 if(get_bits1(&s->gb)==0) 185 return -1; 186 gfid = get_bits(&s->gb, 2); /* GFID */ 187 }else{ 188 gob_number = get_bits(&s->gb, 5); /* GN */ 189 s->mb_x= 0; 190 s->mb_y= s->gob_index* gob_number; 191 gfid = get_bits(&s->gb, 2); /* GFID */ 192 s->qscale = get_bits(&s->gb, 5); /* GQUANT */ 193 } 194 195 if(s->mb_y >= s->mb_height) 196 return -1; 197 198 if(s->qscale==0) 199 return -1; 200 201 return 0; 202} 203 204/** 205 * finds the next resync_marker 206 * @param p pointer to buffer to scan 207 * @param end pointer to the end of the buffer 208 * @return pointer to the next resync_marker, or end if none was found 209 */ 210const uint8_t *ff_h263_find_resync_marker(const uint8_t *restrict p, const uint8_t * restrict end) 211{ 212 assert(p < end); 213 214 end-=2; 215 p++; 216 for(;p<end; p+=2){ 217 if(!*p){ 218 if (!p[-1] && p[1]) return p - 1; 219 else if(!p[ 1] && p[2]) return p; 220 } 221 } 222 return end+2; 223} 224 225/** 226 * decodes the group of blocks / video packet header. 227 * @return bit position of the resync_marker, or <0 if none was found 228 */ 229int ff_h263_resync(MpegEncContext *s){ 230 int left, pos, ret; 231 232 if(s->codec_id==CODEC_ID_MPEG4){ 233 skip_bits1(&s->gb); 234 align_get_bits(&s->gb); 235 } 236 237 if(show_bits(&s->gb, 16)==0){ 238 pos= get_bits_count(&s->gb); 239 if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4) 240 ret= mpeg4_decode_video_packet_header(s); 241 else 242 ret= h263_decode_gob_header(s); 243 if(ret>=0) 244 return pos; 245 } 246 //OK, it's not where it is supposed to be ... 247 s->gb= s->last_resync_gb; 248 align_get_bits(&s->gb); 249 left= get_bits_left(&s->gb); 250 251 for(;left>16+1+5+5; left-=8){ 252 if(show_bits(&s->gb, 16)==0){ 253 GetBitContext bak= s->gb; 254 255 pos= get_bits_count(&s->gb); 256 if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4) 257 ret= mpeg4_decode_video_packet_header(s); 258 else 259 ret= h263_decode_gob_header(s); 260 if(ret>=0) 261 return pos; 262 263 s->gb= bak; 264 } 265 skip_bits(&s->gb, 8); 266 } 267 268 return -1; 269} 270 271int h263_decode_motion(MpegEncContext * s, int pred, int f_code) 272{ 273 int code, val, sign, shift, l; 274 code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2); 275 276 if (code == 0) 277 return pred; 278 if (code < 0) 279 return 0xffff; 280 281 sign = get_bits1(&s->gb); 282 shift = f_code - 1; 283 val = code; 284 if (shift) { 285 val = (val - 1) << shift; 286 val |= get_bits(&s->gb, shift); 287 val++; 288 } 289 if (sign) 290 val = -val; 291 val += pred; 292 293 /* modulo decoding */ 294 if (!s->h263_long_vectors) { 295 l = INT_BIT - 5 - f_code; 296 val = (val<<l)>>l; 297 } else { 298 /* horrible h263 long vector mode */ 299 if (pred < -31 && val < -63) 300 val += 64; 301 if (pred > 32 && val > 63) 302 val -= 64; 303 304 } 305 return val; 306} 307 308 309/* Decodes RVLC of H.263+ UMV */ 310static int h263p_decode_umotion(MpegEncContext * s, int pred) 311{ 312 int code = 0, sign; 313 314 if (get_bits1(&s->gb)) /* Motion difference = 0 */ 315 return pred; 316 317 code = 2 + get_bits1(&s->gb); 318 319 while (get_bits1(&s->gb)) 320 { 321 code <<= 1; 322 code += get_bits1(&s->gb); 323 } 324 sign = code & 1; 325 code >>= 1; 326 327 code = (sign) ? (pred - code) : (pred + code); 328 dprintf(s->avctx,"H.263+ UMV Motion = %d\n", code); 329 return code; 330 331} 332 333/** 334 * read the next MVs for OBMC. yes this is a ugly hack, feel free to send a patch :) 335 */ 336static void preview_obmc(MpegEncContext *s){ 337 GetBitContext gb= s->gb; 338 339 int cbpc, i, pred_x, pred_y, mx, my; 340 int16_t *mot_val; 341 const int xy= s->mb_x + 1 + s->mb_y * s->mb_stride; 342 const int stride= s->b8_stride*2; 343 344 for(i=0; i<4; i++) 345 s->block_index[i]+= 2; 346 for(i=4; i<6; i++) 347 s->block_index[i]+= 1; 348 s->mb_x++; 349 350 assert(s->pict_type == FF_P_TYPE); 351 352 do{ 353 if (get_bits1(&s->gb)) { 354 /* skip mb */ 355 mot_val = s->current_picture.motion_val[0][ s->block_index[0] ]; 356 mot_val[0 ]= mot_val[2 ]= 357 mot_val[0+stride]= mot_val[2+stride]= 0; 358 mot_val[1 ]= mot_val[3 ]= 359 mot_val[1+stride]= mot_val[3+stride]= 0; 360 361 s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0; 362 goto end; 363 } 364 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2); 365 }while(cbpc == 20); 366 367 if(cbpc & 4){ 368 s->current_picture.mb_type[xy]= MB_TYPE_INTRA; 369 }else{ 370 get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1); 371 if (cbpc & 8) { 372 if(s->modified_quant){ 373 if(get_bits1(&s->gb)) skip_bits(&s->gb, 1); 374 else skip_bits(&s->gb, 5); 375 }else 376 skip_bits(&s->gb, 2); 377 } 378 379 if ((cbpc & 16) == 0) { 380 s->current_picture.mb_type[xy]= MB_TYPE_16x16 | MB_TYPE_L0; 381 /* 16x16 motion prediction */ 382 mot_val= h263_pred_motion(s, 0, 0, &pred_x, &pred_y); 383 if (s->umvplus) 384 mx = h263p_decode_umotion(s, pred_x); 385 else 386 mx = h263_decode_motion(s, pred_x, 1); 387 388 if (s->umvplus) 389 my = h263p_decode_umotion(s, pred_y); 390 else 391 my = h263_decode_motion(s, pred_y, 1); 392 393 mot_val[0 ]= mot_val[2 ]= 394 mot_val[0+stride]= mot_val[2+stride]= mx; 395 mot_val[1 ]= mot_val[3 ]= 396 mot_val[1+stride]= mot_val[3+stride]= my; 397 } else { 398 s->current_picture.mb_type[xy]= MB_TYPE_8x8 | MB_TYPE_L0; 399 for(i=0;i<4;i++) { 400 mot_val = h263_pred_motion(s, i, 0, &pred_x, &pred_y); 401 if (s->umvplus) 402 mx = h263p_decode_umotion(s, pred_x); 403 else 404 mx = h263_decode_motion(s, pred_x, 1); 405 406 if (s->umvplus) 407 my = h263p_decode_umotion(s, pred_y); 408 else 409 my = h263_decode_motion(s, pred_y, 1); 410 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1) 411 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */ 412 mot_val[0] = mx; 413 mot_val[1] = my; 414 } 415 } 416 } 417end: 418 419 for(i=0; i<4; i++) 420 s->block_index[i]-= 2; 421 for(i=4; i<6; i++) 422 s->block_index[i]-= 1; 423 s->mb_x--; 424 425 s->gb= gb; 426} 427 428static void h263_decode_dquant(MpegEncContext *s){ 429 static const int8_t quant_tab[4] = { -1, -2, 1, 2 }; 430 431 if(s->modified_quant){ 432 if(get_bits1(&s->gb)) 433 s->qscale= modified_quant_tab[get_bits1(&s->gb)][ s->qscale ]; 434 else 435 s->qscale= get_bits(&s->gb, 5); 436 }else 437 s->qscale += quant_tab[get_bits(&s->gb, 2)]; 438 ff_set_qscale(s, s->qscale); 439} 440 441static int h263_decode_block(MpegEncContext * s, DCTELEM * block, 442 int n, int coded) 443{ 444 int code, level, i, j, last, run; 445 RLTable *rl = &ff_h263_rl_inter; 446 const uint8_t *scan_table; 447 GetBitContext gb= s->gb; 448 449 scan_table = s->intra_scantable.permutated; 450 if (s->h263_aic && s->mb_intra) { 451 rl = &rl_intra_aic; 452 i = 0; 453 if (s->ac_pred) { 454 if (s->h263_aic_dir) 455 scan_table = s->intra_v_scantable.permutated; /* left */ 456 else 457 scan_table = s->intra_h_scantable.permutated; /* top */ 458 } 459 } else if (s->mb_intra) { 460 /* DC coef */ 461 if(s->codec_id == CODEC_ID_RV10){ 462#if CONFIG_RV10_DECODER 463 if (s->rv10_version == 3 && s->pict_type == FF_I_TYPE) { 464 int component, diff; 465 component = (n <= 3 ? 0 : n - 4 + 1); 466 level = s->last_dc[component]; 467 if (s->rv10_first_dc_coded[component]) { 468 diff = rv_decode_dc(s, n); 469 if (diff == 0xffff) 470 return -1; 471 level += diff; 472 level = level & 0xff; /* handle wrap round */ 473 s->last_dc[component] = level; 474 } else { 475 s->rv10_first_dc_coded[component] = 1; 476 } 477 } else { 478 level = get_bits(&s->gb, 8); 479 if (level == 255) 480 level = 128; 481 } 482#endif 483 }else{ 484 level = get_bits(&s->gb, 8); 485 if((level&0x7F) == 0){ 486 av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n", level, s->mb_x, s->mb_y); 487 if(s->error_recognition >= FF_ER_COMPLIANT) 488 return -1; 489 } 490 if (level == 255) 491 level = 128; 492 } 493 block[0] = level; 494 i = 1; 495 } else { 496 i = 0; 497 } 498 if (!coded) { 499 if (s->mb_intra && s->h263_aic) 500 goto not_coded; 501 s->block_last_index[n] = i - 1; 502 return 0; 503 } 504retry: 505 for(;;) { 506 code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2); 507 if (code < 0){ 508 av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y); 509 return -1; 510 } 511 if (code == rl->n) { 512 /* escape */ 513 if (CONFIG_FLV_DECODER && s->h263_flv > 1) { 514 ff_flv2_decode_ac_esc(&s->gb, &level, &run, &last); 515 } else { 516 last = get_bits1(&s->gb); 517 run = get_bits(&s->gb, 6); 518 level = (int8_t)get_bits(&s->gb, 8); 519 if(level == -128){ 520 if (s->codec_id == CODEC_ID_RV10) { 521 /* XXX: should patch encoder too */ 522 level = get_sbits(&s->gb, 12); 523 }else{ 524 level = get_bits(&s->gb, 5); 525 level |= get_sbits(&s->gb, 6)<<5; 526 } 527 } 528 } 529 } else { 530 run = rl->table_run[code]; 531 level = rl->table_level[code]; 532 last = code >= rl->last; 533 if (get_bits1(&s->gb)) 534 level = -level; 535 } 536 i += run; 537 if (i >= 64){ 538 if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){ 539 //Looks like a hack but no, it's the way it is supposed to work ... 540 rl = &rl_intra_aic; 541 i = 0; 542 s->gb= gb; 543 s->dsp.clear_block(block); 544 goto retry; 545 } 546 av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", s->mb_x, s->mb_y, s->mb_intra); 547 return -1; 548 } 549 j = scan_table[i]; 550 block[j] = level; 551 if (last) 552 break; 553 i++; 554 } 555not_coded: 556 if (s->mb_intra && s->h263_aic) { 557 h263_pred_acdc(s, block, n); 558 i = 63; 559 } 560 s->block_last_index[n] = i; 561 return 0; 562} 563 564static int h263_skip_b_part(MpegEncContext *s, int cbp) 565{ 566 LOCAL_ALIGNED_16(DCTELEM, dblock, [64]); 567 int i, mbi; 568 569 /* we have to set s->mb_intra to zero to decode B-part of PB-frame correctly 570 * but real value should be restored in order to be used later (in OBMC condition) 571 */ 572 mbi = s->mb_intra; 573 s->mb_intra = 0; 574 for (i = 0; i < 6; i++) { 575 if (h263_decode_block(s, dblock, i, cbp&32) < 0) 576 return -1; 577 cbp+=cbp; 578 } 579 s->mb_intra = mbi; 580 return 0; 581} 582 583static int h263_get_modb(GetBitContext *gb, int pb_frame, int *cbpb) 584{ 585 int c, mv = 1; 586 587 if (pb_frame < 3) { // h.263 Annex G and i263 PB-frame 588 c = get_bits1(gb); 589 if (pb_frame == 2 && c) 590 mv = !get_bits1(gb); 591 } else { // h.263 Annex M improved PB-frame 592 mv = get_unary(gb, 0, 4) + 1; 593 c = mv & 1; 594 mv = !!(mv & 2); 595 } 596 if(c) 597 *cbpb = get_bits(gb, 6); 598 return mv; 599} 600 601int ff_h263_decode_mb(MpegEncContext *s, 602 DCTELEM block[6][64]) 603{ 604 int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant; 605 int16_t *mot_val; 606 const int xy= s->mb_x + s->mb_y * s->mb_stride; 607 int cbpb = 0, pb_mv_count = 0; 608 609 assert(!s->h263_pred); 610 611 if (s->pict_type == FF_P_TYPE) { 612 do{ 613 if (get_bits1(&s->gb)) { 614 /* skip mb */ 615 s->mb_intra = 0; 616 for(i=0;i<6;i++) 617 s->block_last_index[i] = -1; 618 s->mv_dir = MV_DIR_FORWARD; 619 s->mv_type = MV_TYPE_16X16; 620 s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0; 621 s->mv[0][0][0] = 0; 622 s->mv[0][0][1] = 0; 623 s->mb_skipped = !(s->obmc | s->loop_filter); 624 goto end; 625 } 626 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2); 627 if (cbpc < 0){ 628 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y); 629 return -1; 630 } 631 }while(cbpc == 20); 632 633 s->dsp.clear_blocks(s->block[0]); 634 635 dquant = cbpc & 8; 636 s->mb_intra = ((cbpc & 4) != 0); 637 if (s->mb_intra) goto intra; 638 639 if(s->pb_frame && get_bits1(&s->gb)) 640 pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb); 641 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1); 642 643 if(s->alt_inter_vlc==0 || (cbpc & 3)!=3) 644 cbpy ^= 0xF; 645 646 cbp = (cbpc & 3) | (cbpy << 2); 647 if (dquant) { 648 h263_decode_dquant(s); 649 } 650 651 s->mv_dir = MV_DIR_FORWARD; 652 if ((cbpc & 16) == 0) { 653 s->current_picture.mb_type[xy]= MB_TYPE_16x16 | MB_TYPE_L0; 654 /* 16x16 motion prediction */ 655 s->mv_type = MV_TYPE_16X16; 656 h263_pred_motion(s, 0, 0, &pred_x, &pred_y); 657 if (s->umvplus) 658 mx = h263p_decode_umotion(s, pred_x); 659 else 660 mx = h263_decode_motion(s, pred_x, 1); 661 662 if (mx >= 0xffff) 663 return -1; 664 665 if (s->umvplus) 666 my = h263p_decode_umotion(s, pred_y); 667 else 668 my = h263_decode_motion(s, pred_y, 1); 669 670 if (my >= 0xffff) 671 return -1; 672 s->mv[0][0][0] = mx; 673 s->mv[0][0][1] = my; 674 675 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1) 676 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */ 677 } else { 678 s->current_picture.mb_type[xy]= MB_TYPE_8x8 | MB_TYPE_L0; 679 s->mv_type = MV_TYPE_8X8; 680 for(i=0;i<4;i++) { 681 mot_val = h263_pred_motion(s, i, 0, &pred_x, &pred_y); 682 if (s->umvplus) 683 mx = h263p_decode_umotion(s, pred_x); 684 else 685 mx = h263_decode_motion(s, pred_x, 1); 686 if (mx >= 0xffff) 687 return -1; 688 689 if (s->umvplus) 690 my = h263p_decode_umotion(s, pred_y); 691 else 692 my = h263_decode_motion(s, pred_y, 1); 693 if (my >= 0xffff) 694 return -1; 695 s->mv[0][i][0] = mx; 696 s->mv[0][i][1] = my; 697 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1) 698 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */ 699 mot_val[0] = mx; 700 mot_val[1] = my; 701 } 702 } 703 } else if(s->pict_type==FF_B_TYPE) { 704 int mb_type; 705 const int stride= s->b8_stride; 706 int16_t *mot_val0 = s->current_picture.motion_val[0][ 2*(s->mb_x + s->mb_y*stride) ]; 707 int16_t *mot_val1 = s->current_picture.motion_val[1][ 2*(s->mb_x + s->mb_y*stride) ]; 708// const int mv_xy= s->mb_x + 1 + s->mb_y * s->mb_stride; 709 710 //FIXME ugly 711 mot_val0[0 ]= mot_val0[2 ]= mot_val0[0+2*stride]= mot_val0[2+2*stride]= 712 mot_val0[1 ]= mot_val0[3 ]= mot_val0[1+2*stride]= mot_val0[3+2*stride]= 713 mot_val1[0 ]= mot_val1[2 ]= mot_val1[0+2*stride]= mot_val1[2+2*stride]= 714 mot_val1[1 ]= mot_val1[3 ]= mot_val1[1+2*stride]= mot_val1[3+2*stride]= 0; 715 716 do{ 717 mb_type= get_vlc2(&s->gb, h263_mbtype_b_vlc.table, H263_MBTYPE_B_VLC_BITS, 2); 718 if (mb_type < 0){ 719 av_log(s->avctx, AV_LOG_ERROR, "b mb_type damaged at %d %d\n", s->mb_x, s->mb_y); 720 return -1; 721 } 722 723 mb_type= h263_mb_type_b_map[ mb_type ]; 724 }while(!mb_type); 725 726 s->mb_intra = IS_INTRA(mb_type); 727 if(HAS_CBP(mb_type)){ 728 s->dsp.clear_blocks(s->block[0]); 729 cbpc = get_vlc2(&s->gb, cbpc_b_vlc.table, CBPC_B_VLC_BITS, 1); 730 if(s->mb_intra){ 731 dquant = IS_QUANT(mb_type); 732 goto intra; 733 } 734 735 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1); 736 737 if (cbpy < 0){ 738 av_log(s->avctx, AV_LOG_ERROR, "b cbpy damaged at %d %d\n", s->mb_x, s->mb_y); 739 return -1; 740 } 741 742 if(s->alt_inter_vlc==0 || (cbpc & 3)!=3) 743 cbpy ^= 0xF; 744 745 cbp = (cbpc & 3) | (cbpy << 2); 746 }else 747 cbp=0; 748 749 assert(!s->mb_intra); 750 751 if(IS_QUANT(mb_type)){ 752 h263_decode_dquant(s); 753 } 754 755 if(IS_DIRECT(mb_type)){ 756 s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT; 757 mb_type |= ff_mpeg4_set_direct_mv(s, 0, 0); 758 }else{ 759 s->mv_dir = 0; 760 s->mv_type= MV_TYPE_16X16; 761//FIXME UMV 762 763 if(USES_LIST(mb_type, 0)){ 764 int16_t *mot_val= h263_pred_motion(s, 0, 0, &mx, &my); 765 s->mv_dir = MV_DIR_FORWARD; 766 767 mx = h263_decode_motion(s, mx, 1); 768 my = h263_decode_motion(s, my, 1); 769 770 s->mv[0][0][0] = mx; 771 s->mv[0][0][1] = my; 772 mot_val[0 ]= mot_val[2 ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx; 773 mot_val[1 ]= mot_val[3 ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my; 774 } 775 776 if(USES_LIST(mb_type, 1)){ 777 int16_t *mot_val= h263_pred_motion(s, 0, 1, &mx, &my); 778 s->mv_dir |= MV_DIR_BACKWARD; 779 780 mx = h263_decode_motion(s, mx, 1); 781 my = h263_decode_motion(s, my, 1); 782 783 s->mv[1][0][0] = mx; 784 s->mv[1][0][1] = my; 785 mot_val[0 ]= mot_val[2 ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx; 786 mot_val[1 ]= mot_val[3 ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my; 787 } 788 } 789 790 s->current_picture.mb_type[xy]= mb_type; 791 } else { /* I-Frame */ 792 do{ 793 cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2); 794 if (cbpc < 0){ 795 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y); 796 return -1; 797 } 798 }while(cbpc == 8); 799 800 s->dsp.clear_blocks(s->block[0]); 801 802 dquant = cbpc & 4; 803 s->mb_intra = 1; 804intra: 805 s->current_picture.mb_type[xy]= MB_TYPE_INTRA; 806 if (s->h263_aic) { 807 s->ac_pred = get_bits1(&s->gb); 808 if(s->ac_pred){ 809 s->current_picture.mb_type[xy]= MB_TYPE_INTRA | MB_TYPE_ACPRED; 810 811 s->h263_aic_dir = get_bits1(&s->gb); 812 } 813 }else 814 s->ac_pred = 0; 815 816 if(s->pb_frame && get_bits1(&s->gb)) 817 pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb); 818 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1); 819 if(cbpy<0){ 820 av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y); 821 return -1; 822 } 823 cbp = (cbpc & 3) | (cbpy << 2); 824 if (dquant) { 825 h263_decode_dquant(s); 826 } 827 828 pb_mv_count += !!s->pb_frame; 829 } 830 831 while(pb_mv_count--){ 832 h263_decode_motion(s, 0, 1); 833 h263_decode_motion(s, 0, 1); 834 } 835 836 /* decode each block */ 837 for (i = 0; i < 6; i++) { 838 if (h263_decode_block(s, block[i], i, cbp&32) < 0) 839 return -1; 840 cbp+=cbp; 841 } 842 843 if(s->pb_frame && h263_skip_b_part(s, cbpb) < 0) 844 return -1; 845 if(s->obmc && !s->mb_intra){ 846 if(s->pict_type == FF_P_TYPE && s->mb_x+1<s->mb_width && s->mb_num_left != 1) 847 preview_obmc(s); 848 } 849end: 850 851 /* per-MB end of slice check */ 852 { 853 int v= show_bits(&s->gb, 16); 854 855 if(get_bits_count(&s->gb) + 16 > s->gb.size_in_bits){ 856 v>>= get_bits_count(&s->gb) + 16 - s->gb.size_in_bits; 857 } 858 859 if(v==0) 860 return SLICE_END; 861 } 862 863 return SLICE_OK; 864} 865 866/* most is hardcoded. should extend to handle all h263 streams */ 867int h263_decode_picture_header(MpegEncContext *s) 868{ 869 int format, width, height, i; 870 uint32_t startcode; 871 872 align_get_bits(&s->gb); 873 874 startcode= get_bits(&s->gb, 22-8); 875 876 for(i= get_bits_left(&s->gb); i>24; i-=8) { 877 startcode = ((startcode << 8) | get_bits(&s->gb, 8)) & 0x003FFFFF; 878 879 if(startcode == 0x20) 880 break; 881 } 882 883 if (startcode != 0x20) { 884 av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n"); 885 return -1; 886 } 887 /* temporal reference */ 888 i = get_bits(&s->gb, 8); /* picture timestamp */ 889 if( (s->picture_number&~0xFF)+i < s->picture_number) 890 i+= 256; 891 s->current_picture_ptr->pts= 892 s->picture_number= (s->picture_number&~0xFF) + i; 893 894 /* PTYPE starts here */ 895 if (get_bits1(&s->gb) != 1) { 896 /* marker */ 897 av_log(s->avctx, AV_LOG_ERROR, "Bad marker\n"); 898 return -1; 899 } 900 if (get_bits1(&s->gb) != 0) { 901 av_log(s->avctx, AV_LOG_ERROR, "Bad H263 id\n"); 902 return -1; /* h263 id */ 903 } 904 skip_bits1(&s->gb); /* split screen off */ 905 skip_bits1(&s->gb); /* camera off */ 906 skip_bits1(&s->gb); /* freeze picture release off */ 907 908 format = get_bits(&s->gb, 3); 909 /* 910 0 forbidden 911 1 sub-QCIF 912 10 QCIF 913 7 extended PTYPE (PLUSPTYPE) 914 */ 915 916 if (format != 7 && format != 6) { 917 s->h263_plus = 0; 918 /* H.263v1 */ 919 width = h263_format[format][0]; 920 height = h263_format[format][1]; 921 if (!width) 922 return -1; 923 924 s->pict_type = FF_I_TYPE + get_bits1(&s->gb); 925 926 s->h263_long_vectors = get_bits1(&s->gb); 927 928 if (get_bits1(&s->gb) != 0) { 929 av_log(s->avctx, AV_LOG_ERROR, "H263 SAC not supported\n"); 930 return -1; /* SAC: off */ 931 } 932 s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */ 933 s->unrestricted_mv = s->h263_long_vectors || s->obmc; 934 935 s->pb_frame = get_bits1(&s->gb); 936 s->chroma_qscale= s->qscale = get_bits(&s->gb, 5); 937 skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */ 938 939 s->width = width; 940 s->height = height; 941 s->avctx->sample_aspect_ratio= (AVRational){12,11}; 942 s->avctx->time_base= (AVRational){1001, 30000}; 943 } else { 944 int ufep; 945 946 /* H.263v2 */ 947 s->h263_plus = 1; 948 ufep = get_bits(&s->gb, 3); /* Update Full Extended PTYPE */ 949 950 /* ufep other than 0 and 1 are reserved */ 951 if (ufep == 1) { 952 /* OPPTYPE */ 953 format = get_bits(&s->gb, 3); 954 dprintf(s->avctx, "ufep=1, format: %d\n", format); 955 s->custom_pcf= get_bits1(&s->gb); 956 s->umvplus = get_bits1(&s->gb); /* Unrestricted Motion Vector */ 957 if (get_bits1(&s->gb) != 0) { 958 av_log(s->avctx, AV_LOG_ERROR, "Syntax-based Arithmetic Coding (SAC) not supported\n"); 959 } 960 s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */ 961 s->h263_aic = get_bits1(&s->gb); /* Advanced Intra Coding (AIC) */ 962 s->loop_filter= get_bits1(&s->gb); 963 s->unrestricted_mv = s->umvplus || s->obmc || s->loop_filter; 964 965 s->h263_slice_structured= get_bits1(&s->gb); 966 if (get_bits1(&s->gb) != 0) { 967 av_log(s->avctx, AV_LOG_ERROR, "Reference Picture Selection not supported\n"); 968 } 969 if (get_bits1(&s->gb) != 0) { 970 av_log(s->avctx, AV_LOG_ERROR, "Independent Segment Decoding not supported\n"); 971 } 972 s->alt_inter_vlc= get_bits1(&s->gb); 973 s->modified_quant= get_bits1(&s->gb); 974 if(s->modified_quant) 975 s->chroma_qscale_table= ff_h263_chroma_qscale_table; 976 977 skip_bits(&s->gb, 1); /* Prevent start code emulation */ 978 979 skip_bits(&s->gb, 3); /* Reserved */ 980 } else if (ufep != 0) { 981 av_log(s->avctx, AV_LOG_ERROR, "Bad UFEP type (%d)\n", ufep); 982 return -1; 983 } 984 985 /* MPPTYPE */ 986 s->pict_type = get_bits(&s->gb, 3); 987 switch(s->pict_type){ 988 case 0: s->pict_type= FF_I_TYPE;break; 989 case 1: s->pict_type= FF_P_TYPE;break; 990 case 2: s->pict_type= FF_P_TYPE;s->pb_frame = 3;break; 991 case 3: s->pict_type= FF_B_TYPE;break; 992 case 7: s->pict_type= FF_I_TYPE;break; //ZYGO 993 default: 994 return -1; 995 } 996 skip_bits(&s->gb, 2); 997 s->no_rounding = get_bits1(&s->gb); 998 skip_bits(&s->gb, 4); 999 1000 /* Get the picture dimensions */ 1001 if (ufep) { 1002 if (format == 6) { 1003 /* Custom Picture Format (CPFMT) */ 1004 s->aspect_ratio_info = get_bits(&s->gb, 4); 1005 dprintf(s->avctx, "aspect: %d\n", s->aspect_ratio_info); 1006 /* aspect ratios: 1007 0 - forbidden 1008 1 - 1:1 1009 2 - 12:11 (CIF 4:3) 1010 3 - 10:11 (525-type 4:3) 1011 4 - 16:11 (CIF 16:9) 1012 5 - 40:33 (525-type 16:9) 1013 6-14 - reserved 1014 */ 1015 width = (get_bits(&s->gb, 9) + 1) * 4; 1016 skip_bits1(&s->gb); 1017 height = get_bits(&s->gb, 9) * 4; 1018 dprintf(s->avctx, "\nH.263+ Custom picture: %dx%d\n",width,height); 1019 if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) { 1020 /* aspected dimensions */ 1021 s->avctx->sample_aspect_ratio.num= get_bits(&s->gb, 8); 1022 s->avctx->sample_aspect_ratio.den= get_bits(&s->gb, 8); 1023 }else{ 1024 s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info]; 1025 } 1026 } else { 1027 width = h263_format[format][0]; 1028 height = h263_format[format][1]; 1029 s->avctx->sample_aspect_ratio= (AVRational){12,11}; 1030 } 1031 if ((width == 0) || (height == 0)) 1032 return -1; 1033 s->width = width; 1034 s->height = height; 1035 1036 if(s->custom_pcf){ 1037 int gcd; 1038 s->avctx->time_base.den= 1800000; 1039 s->avctx->time_base.num= 1000 + get_bits1(&s->gb); 1040 s->avctx->time_base.num*= get_bits(&s->gb, 7); 1041 if(s->avctx->time_base.num == 0){ 1042 av_log(s, AV_LOG_ERROR, "zero framerate\n"); 1043 return -1; 1044 } 1045 gcd= av_gcd(s->avctx->time_base.den, s->avctx->time_base.num); 1046 s->avctx->time_base.den /= gcd; 1047 s->avctx->time_base.num /= gcd; 1048 }else{ 1049 s->avctx->time_base= (AVRational){1001, 30000}; 1050 } 1051 } 1052 1053 if(s->custom_pcf){ 1054 skip_bits(&s->gb, 2); //extended Temporal reference 1055 } 1056 1057 if (ufep) { 1058 if (s->umvplus) { 1059 if(get_bits1(&s->gb)==0) /* Unlimited Unrestricted Motion Vectors Indicator (UUI) */ 1060 skip_bits1(&s->gb); 1061 } 1062 if(s->h263_slice_structured){ 1063 if (get_bits1(&s->gb) != 0) { 1064 av_log(s->avctx, AV_LOG_ERROR, "rectangular slices not supported\n"); 1065 } 1066 if (get_bits1(&s->gb) != 0) { 1067 av_log(s->avctx, AV_LOG_ERROR, "unordered slices not supported\n"); 1068 } 1069 } 1070 } 1071 1072 s->qscale = get_bits(&s->gb, 5); 1073 } 1074 1075 s->mb_width = (s->width + 15) / 16; 1076 s->mb_height = (s->height + 15) / 16; 1077 s->mb_num = s->mb_width * s->mb_height; 1078 1079 if (s->pb_frame) { 1080 skip_bits(&s->gb, 3); /* Temporal reference for B-pictures */ 1081 if (s->custom_pcf) 1082 skip_bits(&s->gb, 2); //extended Temporal reference 1083 skip_bits(&s->gb, 2); /* Quantization information for B-pictures */ 1084 } 1085 1086 /* PEI */ 1087 while (get_bits1(&s->gb) != 0) { 1088 skip_bits(&s->gb, 8); 1089 } 1090 1091 if(s->h263_slice_structured){ 1092 if (get_bits1(&s->gb) != 1) { 1093 av_log(s->avctx, AV_LOG_ERROR, "SEPB1 marker missing\n"); 1094 return -1; 1095 } 1096 1097 ff_h263_decode_mba(s); 1098 1099 if (get_bits1(&s->gb) != 1) { 1100 av_log(s->avctx, AV_LOG_ERROR, "SEPB2 marker missing\n"); 1101 return -1; 1102 } 1103 } 1104 s->f_code = 1; 1105 1106 if(s->h263_aic){ 1107 s->y_dc_scale_table= 1108 s->c_dc_scale_table= ff_aic_dc_scale_table; 1109 }else{ 1110 s->y_dc_scale_table= 1111 s->c_dc_scale_table= ff_mpeg1_dc_scale_table; 1112 } 1113 1114 ff_h263_show_pict_info(s); 1115 if (s->pict_type == FF_I_TYPE && s->codec_tag == AV_RL32("ZYGO")){ 1116 int i,j; 1117 for(i=0; i<85; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb)); 1118 av_log(s->avctx, AV_LOG_DEBUG, "\n"); 1119 for(i=0; i<13; i++){ 1120 for(j=0; j<3; j++){ 1121 int v= get_bits(&s->gb, 8); 1122 v |= get_sbits(&s->gb, 8)<<8; 1123 av_log(s->avctx, AV_LOG_DEBUG, " %5d", v); 1124 } 1125 av_log(s->avctx, AV_LOG_DEBUG, "\n"); 1126 } 1127 for(i=0; i<50; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb)); 1128 } 1129 1130 return 0; 1131} 1132