1/* 2 * MSMPEG4 encoder backend 3 * Copyright (c) 2001 Fabrice Bellard 4 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at> 5 * 6 * msmpeg4v1 & v2 stuff by 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 * MSMPEG4 encoder backend 28 */ 29 30#include <stdint.h> 31#include <string.h> 32 33#include "libavutil/attributes.h" 34#include "libavutil/avutil.h" 35#include "libavutil/mem.h" 36#include "mpegvideo.h" 37#include "h263.h" 38#include "mpeg4video.h" 39#include "msmpeg4.h" 40#include "msmpeg4data.h" 41#include "put_bits.h" 42#include "rl.h" 43#include "vc1data.h" 44 45static uint8_t rl_length[NB_RL_TABLES][MAX_LEVEL+1][MAX_RUN+1][2]; 46 47/* build the table which associate a (x,y) motion vector to a vlc */ 48static av_cold void init_mv_table(MVTable *tab) 49{ 50 int i, x, y; 51 52 tab->table_mv_index = av_malloc(sizeof(uint16_t) * 4096); 53 /* mark all entries as not used */ 54 for(i=0;i<4096;i++) 55 tab->table_mv_index[i] = tab->n; 56 57 for(i=0;i<tab->n;i++) { 58 x = tab->table_mvx[i]; 59 y = tab->table_mvy[i]; 60 tab->table_mv_index[(x << 6) | y] = i; 61 } 62} 63 64void ff_msmpeg4_code012(PutBitContext *pb, int n) 65{ 66 if (n == 0) { 67 put_bits(pb, 1, 0); 68 } else { 69 put_bits(pb, 1, 1); 70 put_bits(pb, 1, (n >= 2)); 71 } 72} 73 74static int get_size_of_code(MpegEncContext * s, RLTable *rl, int last, int run, int level, int intra){ 75 int size=0; 76 int code; 77 int run_diff= intra ? 0 : 1; 78 79 code = get_rl_index(rl, last, run, level); 80 size+= rl->table_vlc[code][1]; 81 if (code == rl->n) { 82 int level1, run1; 83 84 level1 = level - rl->max_level[last][run]; 85 if (level1 < 1) 86 goto esc2; 87 code = get_rl_index(rl, last, run, level1); 88 if (code == rl->n) { 89 esc2: 90 size++; 91 if (level > MAX_LEVEL) 92 goto esc3; 93 run1 = run - rl->max_run[last][level] - run_diff; 94 if (run1 < 0) 95 goto esc3; 96 code = get_rl_index(rl, last, run1, level); 97 if (code == rl->n) { 98 esc3: 99 /* third escape */ 100 size+=1+1+6+8; 101 } else { 102 /* second escape */ 103 size+= 1+1+ rl->table_vlc[code][1]; 104 } 105 } else { 106 /* first escape */ 107 size+= 1+1+ rl->table_vlc[code][1]; 108 } 109 } else { 110 size++; 111 } 112 return size; 113} 114 115av_cold void ff_msmpeg4_encode_init(MpegEncContext *s) 116{ 117 static int init_done=0; 118 int i; 119 120 ff_msmpeg4_common_init(s); 121 if(s->msmpeg4_version>=4){ 122 s->min_qcoeff= -255; 123 s->max_qcoeff= 255; 124 } 125 126 if (!init_done) { 127 /* init various encoding tables */ 128 init_done = 1; 129 init_mv_table(&ff_mv_tables[0]); 130 init_mv_table(&ff_mv_tables[1]); 131 for(i=0;i<NB_RL_TABLES;i++) 132 ff_init_rl(&ff_rl_table[i], ff_static_rl_table_store[i]); 133 134 for(i=0; i<NB_RL_TABLES; i++){ 135 int level; 136 for (level = 1; level <= MAX_LEVEL; level++) { 137 int run; 138 for(run=0; run<=MAX_RUN; run++){ 139 int last; 140 for(last=0; last<2; last++){ 141 rl_length[i][level][run][last]= get_size_of_code(s, &ff_rl_table[ i], last, run, level, 0); 142 } 143 } 144 } 145 } 146 } 147} 148 149static void find_best_tables(MpegEncContext * s) 150{ 151 int i; 152 int best = 0, best_size = INT_MAX; 153 int chroma_best = 0, best_chroma_size = INT_MAX; 154 155 for(i=0; i<3; i++){ 156 int level; 157 int chroma_size=0; 158 int size=0; 159 160 if(i>0){// ;) 161 size++; 162 chroma_size++; 163 } 164 for(level=0; level<=MAX_LEVEL; level++){ 165 int run; 166 for(run=0; run<=MAX_RUN; run++){ 167 int last; 168 const int last_size= size + chroma_size; 169 for(last=0; last<2; last++){ 170 int inter_count = s->ac_stats[0][0][level][run][last] + s->ac_stats[0][1][level][run][last]; 171 int intra_luma_count = s->ac_stats[1][0][level][run][last]; 172 int intra_chroma_count= s->ac_stats[1][1][level][run][last]; 173 174 if(s->pict_type==AV_PICTURE_TYPE_I){ 175 size += intra_luma_count *rl_length[i ][level][run][last]; 176 chroma_size+= intra_chroma_count*rl_length[i+3][level][run][last]; 177 }else{ 178 size+= intra_luma_count *rl_length[i ][level][run][last] 179 +intra_chroma_count*rl_length[i+3][level][run][last] 180 +inter_count *rl_length[i+3][level][run][last]; 181 } 182 } 183 if(last_size == size+chroma_size) break; 184 } 185 } 186 if(size<best_size){ 187 best_size= size; 188 best= i; 189 } 190 if(chroma_size<best_chroma_size){ 191 best_chroma_size= chroma_size; 192 chroma_best= i; 193 } 194 } 195 196 if(s->pict_type==AV_PICTURE_TYPE_P) chroma_best= best; 197 198 memset(s->ac_stats, 0, sizeof(int)*(MAX_LEVEL+1)*(MAX_RUN+1)*2*2*2); 199 200 s->rl_table_index = best; 201 s->rl_chroma_table_index= chroma_best; 202 203 if(s->pict_type != s->last_non_b_pict_type){ 204 s->rl_table_index= 2; 205 if(s->pict_type==AV_PICTURE_TYPE_I) 206 s->rl_chroma_table_index= 1; 207 else 208 s->rl_chroma_table_index= 2; 209 } 210 211} 212 213/* write MSMPEG4 compatible frame header */ 214void ff_msmpeg4_encode_picture_header(MpegEncContext * s, int picture_number) 215{ 216 find_best_tables(s); 217 218 avpriv_align_put_bits(&s->pb); 219 put_bits(&s->pb, 2, s->pict_type - 1); 220 221 put_bits(&s->pb, 5, s->qscale); 222 if(s->msmpeg4_version<=2){ 223 s->rl_table_index = 2; 224 s->rl_chroma_table_index = 2; 225 } 226 227 s->dc_table_index = 1; 228 s->mv_table_index = 1; /* only if P frame */ 229 s->use_skip_mb_code = 1; /* only if P frame */ 230 s->per_mb_rl_table = 0; 231 if(s->msmpeg4_version==4) 232 s->inter_intra_pred= (s->width*s->height < 320*240 && s->bit_rate<=II_BITRATE && s->pict_type==AV_PICTURE_TYPE_P); 233 av_dlog(s, "%d %d %d %d %d\n", s->pict_type, s->bit_rate, 234 s->inter_intra_pred, s->width, s->height); 235 236 if (s->pict_type == AV_PICTURE_TYPE_I) { 237 s->slice_height= s->mb_height/1; 238 put_bits(&s->pb, 5, 0x16 + s->mb_height/s->slice_height); 239 240 if(s->msmpeg4_version==4){ 241 ff_msmpeg4_encode_ext_header(s); 242 if(s->bit_rate>MBAC_BITRATE) 243 put_bits(&s->pb, 1, s->per_mb_rl_table); 244 } 245 246 if(s->msmpeg4_version>2){ 247 if(!s->per_mb_rl_table){ 248 ff_msmpeg4_code012(&s->pb, s->rl_chroma_table_index); 249 ff_msmpeg4_code012(&s->pb, s->rl_table_index); 250 } 251 252 put_bits(&s->pb, 1, s->dc_table_index); 253 } 254 } else { 255 put_bits(&s->pb, 1, s->use_skip_mb_code); 256 257 if(s->msmpeg4_version==4 && s->bit_rate>MBAC_BITRATE) 258 put_bits(&s->pb, 1, s->per_mb_rl_table); 259 260 if(s->msmpeg4_version>2){ 261 if(!s->per_mb_rl_table) 262 ff_msmpeg4_code012(&s->pb, s->rl_table_index); 263 264 put_bits(&s->pb, 1, s->dc_table_index); 265 266 put_bits(&s->pb, 1, s->mv_table_index); 267 } 268 } 269 270 s->esc3_level_length= 0; 271 s->esc3_run_length= 0; 272} 273 274void ff_msmpeg4_encode_ext_header(MpegEncContext * s) 275{ 276 unsigned fps = s->avctx->time_base.den / s->avctx->time_base.num / FFMAX(s->avctx->ticks_per_frame, 1); 277 put_bits(&s->pb, 5, FFMIN(fps, 31)); //yes 29.97 -> 29 278 279 put_bits(&s->pb, 11, FFMIN(s->bit_rate/1024, 2047)); 280 281 if(s->msmpeg4_version>=3) 282 put_bits(&s->pb, 1, s->flipflop_rounding); 283 else 284 av_assert0(s->flipflop_rounding==0); 285} 286 287void ff_msmpeg4_encode_motion(MpegEncContext * s, 288 int mx, int my) 289{ 290 int code; 291 MVTable *mv; 292 293 /* modulo encoding */ 294 /* WARNING : you cannot reach all the MVs even with the modulo 295 encoding. This is a somewhat strange compromise they took !!! */ 296 if (mx <= -64) 297 mx += 64; 298 else if (mx >= 64) 299 mx -= 64; 300 if (my <= -64) 301 my += 64; 302 else if (my >= 64) 303 my -= 64; 304 305 mx += 32; 306 my += 32; 307#if 0 308 if ((unsigned)mx >= 64 || 309 (unsigned)my >= 64) 310 av_log(s->avctx, AV_LOG_ERROR, "error mx=%d my=%d\n", mx, my); 311#endif 312 mv = &ff_mv_tables[s->mv_table_index]; 313 314 code = mv->table_mv_index[(mx << 6) | my]; 315 put_bits(&s->pb, 316 mv->table_mv_bits[code], 317 mv->table_mv_code[code]); 318 if (code == mv->n) { 319 /* escape : code literally */ 320 put_bits(&s->pb, 6, mx); 321 put_bits(&s->pb, 6, my); 322 } 323} 324 325void ff_msmpeg4_handle_slices(MpegEncContext *s){ 326 if (s->mb_x == 0) { 327 if (s->slice_height && (s->mb_y % s->slice_height) == 0) { 328 if(s->msmpeg4_version < 4){ 329 ff_mpeg4_clean_buffers(s); 330 } 331 s->first_slice_line = 1; 332 } else { 333 s->first_slice_line = 0; 334 } 335 } 336} 337 338static void msmpeg4v2_encode_motion(MpegEncContext * s, int val) 339{ 340 int range, bit_size, sign, code, bits; 341 342 if (val == 0) { 343 /* zero vector */ 344 code = 0; 345 put_bits(&s->pb, ff_mvtab[code][1], ff_mvtab[code][0]); 346 } else { 347 bit_size = s->f_code - 1; 348 range = 1 << bit_size; 349 if (val <= -64) 350 val += 64; 351 else if (val >= 64) 352 val -= 64; 353 354 if (val >= 0) { 355 sign = 0; 356 } else { 357 val = -val; 358 sign = 1; 359 } 360 val--; 361 code = (val >> bit_size) + 1; 362 bits = val & (range - 1); 363 364 put_bits(&s->pb, ff_mvtab[code][1] + 1, (ff_mvtab[code][0] << 1) | sign); 365 if (bit_size > 0) { 366 put_bits(&s->pb, bit_size, bits); 367 } 368 } 369} 370 371void ff_msmpeg4_encode_mb(MpegEncContext * s, 372 int16_t block[6][64], 373 int motion_x, int motion_y) 374{ 375 int cbp, coded_cbp, i; 376 int pred_x, pred_y; 377 uint8_t *coded_block; 378 379 ff_msmpeg4_handle_slices(s); 380 381 if (!s->mb_intra) { 382 /* compute cbp */ 383 cbp = 0; 384 for (i = 0; i < 6; i++) { 385 if (s->block_last_index[i] >= 0) 386 cbp |= 1 << (5 - i); 387 } 388 if (s->use_skip_mb_code && (cbp | motion_x | motion_y) == 0) { 389 /* skip macroblock */ 390 put_bits(&s->pb, 1, 1); 391 s->last_bits++; 392 s->misc_bits++; 393 s->skip_count++; 394 395 return; 396 } 397 if (s->use_skip_mb_code) 398 put_bits(&s->pb, 1, 0); /* mb coded */ 399 400 if(s->msmpeg4_version<=2){ 401 put_bits(&s->pb, 402 ff_v2_mb_type[cbp&3][1], 403 ff_v2_mb_type[cbp&3][0]); 404 if((cbp&3) != 3) coded_cbp= cbp ^ 0x3C; 405 else coded_cbp= cbp; 406 407 put_bits(&s->pb, 408 ff_h263_cbpy_tab[coded_cbp>>2][1], 409 ff_h263_cbpy_tab[coded_cbp>>2][0]); 410 411 s->misc_bits += get_bits_diff(s); 412 413 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y); 414 msmpeg4v2_encode_motion(s, motion_x - pred_x); 415 msmpeg4v2_encode_motion(s, motion_y - pred_y); 416 }else{ 417 put_bits(&s->pb, 418 ff_table_mb_non_intra[cbp + 64][1], 419 ff_table_mb_non_intra[cbp + 64][0]); 420 421 s->misc_bits += get_bits_diff(s); 422 423 /* motion vector */ 424 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y); 425 ff_msmpeg4_encode_motion(s, motion_x - pred_x, 426 motion_y - pred_y); 427 } 428 429 s->mv_bits += get_bits_diff(s); 430 431 for (i = 0; i < 6; i++) { 432 ff_msmpeg4_encode_block(s, block[i], i); 433 } 434 s->p_tex_bits += get_bits_diff(s); 435 } else { 436 /* compute cbp */ 437 cbp = 0; 438 coded_cbp = 0; 439 for (i = 0; i < 6; i++) { 440 int val, pred; 441 val = (s->block_last_index[i] >= 1); 442 cbp |= val << (5 - i); 443 if (i < 4) { 444 /* predict value for close blocks only for luma */ 445 pred = ff_msmpeg4_coded_block_pred(s, i, &coded_block); 446 *coded_block = val; 447 val = val ^ pred; 448 } 449 coded_cbp |= val << (5 - i); 450 } 451 452 if(s->msmpeg4_version<=2){ 453 if (s->pict_type == AV_PICTURE_TYPE_I) { 454 put_bits(&s->pb, 455 ff_v2_intra_cbpc[cbp&3][1], ff_v2_intra_cbpc[cbp&3][0]); 456 } else { 457 if (s->use_skip_mb_code) 458 put_bits(&s->pb, 1, 0); /* mb coded */ 459 put_bits(&s->pb, 460 ff_v2_mb_type[(cbp&3) + 4][1], 461 ff_v2_mb_type[(cbp&3) + 4][0]); 462 } 463 put_bits(&s->pb, 1, 0); /* no AC prediction yet */ 464 put_bits(&s->pb, 465 ff_h263_cbpy_tab[cbp>>2][1], 466 ff_h263_cbpy_tab[cbp>>2][0]); 467 }else{ 468 if (s->pict_type == AV_PICTURE_TYPE_I) { 469 put_bits(&s->pb, 470 ff_msmp4_mb_i_table[coded_cbp][1], ff_msmp4_mb_i_table[coded_cbp][0]); 471 } else { 472 if (s->use_skip_mb_code) 473 put_bits(&s->pb, 1, 0); /* mb coded */ 474 put_bits(&s->pb, 475 ff_table_mb_non_intra[cbp][1], 476 ff_table_mb_non_intra[cbp][0]); 477 } 478 put_bits(&s->pb, 1, 0); /* no AC prediction yet */ 479 if(s->inter_intra_pred){ 480 s->h263_aic_dir=0; 481 put_bits(&s->pb, ff_table_inter_intra[s->h263_aic_dir][1], ff_table_inter_intra[s->h263_aic_dir][0]); 482 } 483 } 484 s->misc_bits += get_bits_diff(s); 485 486 for (i = 0; i < 6; i++) { 487 ff_msmpeg4_encode_block(s, block[i], i); 488 } 489 s->i_tex_bits += get_bits_diff(s); 490 s->i_count++; 491 } 492} 493 494static void msmpeg4_encode_dc(MpegEncContext * s, int level, int n, int *dir_ptr) 495{ 496 int sign, code; 497 int pred, av_uninit(extquant); 498 int extrabits = 0; 499 500 int16_t *dc_val; 501 pred = ff_msmpeg4_pred_dc(s, n, &dc_val, dir_ptr); 502 503 /* update predictor */ 504 if (n < 4) { 505 *dc_val = level * s->y_dc_scale; 506 } else { 507 *dc_val = level * s->c_dc_scale; 508 } 509 510 /* do the prediction */ 511 level -= pred; 512 513 if(s->msmpeg4_version<=2){ 514 if (n < 4) { 515 put_bits(&s->pb, 516 ff_v2_dc_lum_table[level + 256][1], 517 ff_v2_dc_lum_table[level + 256][0]); 518 }else{ 519 put_bits(&s->pb, 520 ff_v2_dc_chroma_table[level + 256][1], 521 ff_v2_dc_chroma_table[level + 256][0]); 522 } 523 }else{ 524 sign = 0; 525 if (level < 0) { 526 level = -level; 527 sign = 1; 528 } 529 code = level; 530 if (code > DC_MAX) 531 code = DC_MAX; 532 else if( s->msmpeg4_version>=6 ) { 533 if( s->qscale == 1 ) { 534 extquant = (level + 3) & 0x3; 535 code = ((level+3)>>2); 536 } else if( s->qscale == 2 ) { 537 extquant = (level + 1) & 0x1; 538 code = ((level+1)>>1); 539 } 540 } 541 542 if (s->dc_table_index == 0) { 543 if (n < 4) { 544 put_bits(&s->pb, ff_table0_dc_lum[code][1], ff_table0_dc_lum[code][0]); 545 } else { 546 put_bits(&s->pb, ff_table0_dc_chroma[code][1], ff_table0_dc_chroma[code][0]); 547 } 548 } else { 549 if (n < 4) { 550 put_bits(&s->pb, ff_table1_dc_lum[code][1], ff_table1_dc_lum[code][0]); 551 } else { 552 put_bits(&s->pb, ff_table1_dc_chroma[code][1], ff_table1_dc_chroma[code][0]); 553 } 554 } 555 556 if(s->msmpeg4_version>=6 && s->qscale<=2) 557 extrabits = 3 - s->qscale; 558 559 if (code == DC_MAX) 560 put_bits(&s->pb, 8 + extrabits, level); 561 else if(extrabits > 0)//== VC1 && s->qscale<=2 562 put_bits(&s->pb, extrabits, extquant); 563 564 if (level != 0) { 565 put_bits(&s->pb, 1, sign); 566 } 567 } 568} 569 570/* Encoding of a block. Very similar to MPEG4 except for a different 571 escape coding (same as H263) and more vlc tables. 572 */ 573void ff_msmpeg4_encode_block(MpegEncContext * s, int16_t * block, int n) 574{ 575 int level, run, last, i, j, last_index; 576 int last_non_zero, sign, slevel; 577 int code, run_diff, dc_pred_dir; 578 const RLTable *rl; 579 const uint8_t *scantable; 580 581 if (s->mb_intra) { 582 msmpeg4_encode_dc(s, block[0], n, &dc_pred_dir); 583 i = 1; 584 if (n < 4) { 585 rl = &ff_rl_table[s->rl_table_index]; 586 } else { 587 rl = &ff_rl_table[3 + s->rl_chroma_table_index]; 588 } 589 run_diff = s->msmpeg4_version>=4; 590 scantable= s->intra_scantable.permutated; 591 } else { 592 i = 0; 593 rl = &ff_rl_table[3 + s->rl_table_index]; 594 if(s->msmpeg4_version<=2) 595 run_diff = 0; 596 else 597 run_diff = 1; 598 scantable= s->inter_scantable.permutated; 599 } 600 601 /* recalculate block_last_index for M$ wmv1 */ 602 if(s->msmpeg4_version>=4 && s->msmpeg4_version<6 && s->block_last_index[n]>0){ 603 for(last_index=63; last_index>=0; last_index--){ 604 if(block[scantable[last_index]]) break; 605 } 606 s->block_last_index[n]= last_index; 607 }else 608 last_index = s->block_last_index[n]; 609 /* AC coefs */ 610 last_non_zero = i - 1; 611 for (; i <= last_index; i++) { 612 j = scantable[i]; 613 level = block[j]; 614 if (level) { 615 run = i - last_non_zero - 1; 616 last = (i == last_index); 617 sign = 0; 618 slevel = level; 619 if (level < 0) { 620 sign = 1; 621 level = -level; 622 } 623 624 if(level<=MAX_LEVEL && run<=MAX_RUN){ 625 s->ac_stats[s->mb_intra][n>3][level][run][last]++; 626 } 627 628 s->ac_stats[s->mb_intra][n > 3][40][63][0]++; //esc3 like 629 630 code = get_rl_index(rl, last, run, level); 631 put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]); 632 if (code == rl->n) { 633 int level1, run1; 634 635 level1 = level - rl->max_level[last][run]; 636 if (level1 < 1) 637 goto esc2; 638 code = get_rl_index(rl, last, run, level1); 639 if (code == rl->n) { 640 esc2: 641 put_bits(&s->pb, 1, 0); 642 if (level > MAX_LEVEL) 643 goto esc3; 644 run1 = run - rl->max_run[last][level] - run_diff; 645 if (run1 < 0) 646 goto esc3; 647 code = get_rl_index(rl, last, run1+1, level); 648 if (s->msmpeg4_version == 4 && code == rl->n) 649 goto esc3; 650 code = get_rl_index(rl, last, run1, level); 651 if (code == rl->n) { 652 esc3: 653 /* third escape */ 654 put_bits(&s->pb, 1, 0); 655 put_bits(&s->pb, 1, last); 656 if(s->msmpeg4_version>=4){ 657 if(s->esc3_level_length==0){ 658 s->esc3_level_length=8; 659 s->esc3_run_length= 6; 660 //ESCLVLSZ + ESCRUNSZ 661 if(s->qscale<8) 662 put_bits(&s->pb, 6 + (s->msmpeg4_version>=6), 3); 663 else 664 put_bits(&s->pb, 8, 3); 665 } 666 put_bits(&s->pb, s->esc3_run_length, run); 667 put_bits(&s->pb, 1, sign); 668 put_bits(&s->pb, s->esc3_level_length, level); 669 }else{ 670 put_bits(&s->pb, 6, run); 671 put_sbits(&s->pb, 8, slevel); 672 } 673 } else { 674 /* second escape */ 675 put_bits(&s->pb, 1, 1); 676 put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]); 677 put_bits(&s->pb, 1, sign); 678 } 679 } else { 680 /* first escape */ 681 put_bits(&s->pb, 1, 1); 682 put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]); 683 put_bits(&s->pb, 1, sign); 684 } 685 } else { 686 put_bits(&s->pb, 1, sign); 687 } 688 last_non_zero = i; 689 } 690 } 691} 692