jcmaster.c (19363B)
1 /* 2 * jcmaster.c 3 * 4 * Copyright (C) 1991-1995, Thomas G. Lane. 5 * This file is part of the Independent JPEG Group's software. 6 * For conditions of distribution and use, see the accompanying README file. 7 * 8 * This file contains master control logic for the JPEG compressor. 9 * These routines are concerned with parameter validation, initial setup, 10 * and inter-pass control (determining the number of passes and the work 11 * to be done in each pass). 12 */ 13 14 #define JPEG_INTERNALS 15 #include "jinclude.h" 16 #include "jpeglib.h" 17 18 19 /* Private state */ 20 21 typedef enum { 22 main_pass, /* input data, also do first output step */ 23 huff_opt_pass, /* Huffman code optimization pass */ 24 output_pass /* data output pass */ 25 } c_pass_type; 26 27 typedef struct { 28 struct jpeg_comp_master pub; /* public fields */ 29 30 c_pass_type pass_type; /* the type of the current pass */ 31 32 int pass_number; /* # of passes completed */ 33 int total_passes; /* total # of passes needed */ 34 35 int scan_number; /* current index in scan_info[] */ 36 } my_comp_master; 37 38 typedef my_comp_master * my_master_ptr; 39 40 41 /* 42 * Support routines that do various essential calculations. 43 */ 44 45 LOCAL void 46 initial_setup (j_compress_ptr cinfo) 47 /* Do computations that are needed before master selection phase */ 48 { 49 int ci; 50 jpeg_component_info *compptr; 51 long samplesperrow; 52 JDIMENSION jd_samplesperrow; 53 54 /* Sanity check on image dimensions */ 55 if (cinfo->image_height <= 0 || cinfo->image_width <= 0 56 || cinfo->num_components <= 0 || cinfo->input_components <= 0) 57 ERREXIT(cinfo, JERR_EMPTY_IMAGE); 58 59 /* Make sure image isn't bigger than I can handle */ 60 if ((long) cinfo->image_height > (long) JPEG_MAX_DIMENSION || 61 (long) cinfo->image_width > (long) JPEG_MAX_DIMENSION) 62 ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION); 63 64 /* Width of an input scanline must be representable as JDIMENSION. */ 65 samplesperrow = (long) cinfo->image_width * (long) cinfo->input_components; 66 jd_samplesperrow = (JDIMENSION) samplesperrow; 67 if ((long) jd_samplesperrow != samplesperrow) 68 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); 69 70 /* For now, precision must match compiled-in value... */ 71 if (cinfo->data_precision != BITS_IN_JSAMPLE) 72 ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision); 73 74 /* Check that number of components won't exceed internal array sizes */ 75 if (cinfo->num_components > MAX_COMPONENTS) 76 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components, 77 MAX_COMPONENTS); 78 79 /* Compute maximum sampling factors; check factor validity */ 80 cinfo->max_h_samp_factor = 1; 81 cinfo->max_v_samp_factor = 1; 82 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 83 ci++, compptr++) { 84 if (compptr->h_samp_factor<=0 || compptr->h_samp_factor>MAX_SAMP_FACTOR || 85 compptr->v_samp_factor<=0 || compptr->v_samp_factor>MAX_SAMP_FACTOR) 86 ERREXIT(cinfo, JERR_BAD_SAMPLING); 87 cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor, 88 compptr->h_samp_factor); 89 cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor, 90 compptr->v_samp_factor); 91 } 92 93 /* Compute dimensions of components */ 94 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 95 ci++, compptr++) { 96 /* Fill in the correct component_index value; don't rely on application */ 97 compptr->component_index = ci; 98 /* For compression, we never do DCT scaling. */ 99 compptr->DCT_scaled_size = DCTSIZE; 100 /* Size in DCT blocks */ 101 compptr->width_in_blocks = (JDIMENSION) 102 jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor, 103 (long) (cinfo->max_h_samp_factor * DCTSIZE)); 104 compptr->height_in_blocks = (JDIMENSION) 105 jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor, 106 (long) (cinfo->max_v_samp_factor * DCTSIZE)); 107 /* Size in samples */ 108 compptr->downsampled_width = (JDIMENSION) 109 jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor, 110 (long) cinfo->max_h_samp_factor); 111 compptr->downsampled_height = (JDIMENSION) 112 jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor, 113 (long) cinfo->max_v_samp_factor); 114 /* Mark component needed (this flag isn't actually used for compression) */ 115 compptr->component_needed = TRUE; 116 } 117 118 /* Compute number of fully interleaved MCU rows (number of times that 119 * main controller will call coefficient controller). 120 */ 121 cinfo->total_iMCU_rows = (JDIMENSION) 122 jdiv_round_up((long) cinfo->image_height, 123 (long) (cinfo->max_v_samp_factor*DCTSIZE)); 124 } 125 126 127 #ifdef C_MULTISCAN_FILES_SUPPORTED 128 129 LOCAL void 130 validate_script (j_compress_ptr cinfo) 131 /* Verify that the scan script in cinfo->scan_info[] is valid; also 132 * determine whether it uses progressive JPEG, and set cinfo->progressive_mode. 133 */ 134 { 135 const jpeg_scan_info * scanptr; 136 int scanno, ncomps, ci, coefi, thisi; 137 int Ss, Se, Ah, Al; 138 boolean component_sent[MAX_COMPONENTS]; 139 #ifdef C_PROGRESSIVE_SUPPORTED 140 int * last_bitpos_ptr; 141 int last_bitpos[MAX_COMPONENTS][DCTSIZE2]; 142 /* -1 until that coefficient has been seen; then last Al for it */ 143 #endif 144 145 if (cinfo->num_scans <= 0) 146 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, 0); 147 148 /* For sequential JPEG, all scans must have Ss=0, Se=DCTSIZE2-1; 149 * for progressive JPEG, no scan can have this. 150 */ 151 scanptr = cinfo->scan_info; 152 if (scanptr->Ss != 0 || scanptr->Se != DCTSIZE2-1) { 153 #ifdef C_PROGRESSIVE_SUPPORTED 154 cinfo->progressive_mode = TRUE; 155 last_bitpos_ptr = & last_bitpos[0][0]; 156 for (ci = 0; ci < cinfo->num_components; ci++) 157 for (coefi = 0; coefi < DCTSIZE2; coefi++) 158 *last_bitpos_ptr++ = -1; 159 #else 160 ERREXIT(cinfo, JERR_NOT_COMPILED); 161 #endif 162 } else { 163 cinfo->progressive_mode = FALSE; 164 for (ci = 0; ci < cinfo->num_components; ci++) 165 component_sent[ci] = FALSE; 166 } 167 168 for (scanno = 1; scanno <= cinfo->num_scans; scanptr++, scanno++) { 169 /* Validate component indexes */ 170 ncomps = scanptr->comps_in_scan; 171 if (ncomps <= 0 || ncomps > MAX_COMPS_IN_SCAN) 172 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, ncomps, MAX_COMPS_IN_SCAN); 173 for (ci = 0; ci < ncomps; ci++) { 174 thisi = scanptr->component_index[ci]; 175 if (thisi < 0 || thisi >= cinfo->num_components) 176 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno); 177 /* Components must appear in SOF order within each scan */ 178 if (ci > 0 && thisi <= scanptr->component_index[ci-1]) 179 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno); 180 } 181 /* Validate progression parameters */ 182 Ss = scanptr->Ss; 183 Se = scanptr->Se; 184 Ah = scanptr->Ah; 185 Al = scanptr->Al; 186 if (cinfo->progressive_mode) { 187 #ifdef C_PROGRESSIVE_SUPPORTED 188 if (Ss < 0 || Ss >= DCTSIZE2 || Se < Ss || Se >= DCTSIZE2 || 189 Ah < 0 || Ah > 13 || Al < 0 || Al > 13) 190 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 191 if (Ss == 0) { 192 if (Se != 0) /* DC and AC together not OK */ 193 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 194 } else { 195 if (ncomps != 1) /* AC scans must be for only one component */ 196 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 197 } 198 for (ci = 0; ci < ncomps; ci++) { 199 last_bitpos_ptr = & last_bitpos[scanptr->component_index[ci]][0]; 200 if (Ss != 0 && last_bitpos_ptr[0] < 0) /* AC without prior DC scan */ 201 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 202 for (coefi = Ss; coefi <= Se; coefi++) { 203 if (last_bitpos_ptr[coefi] < 0) { 204 /* first scan of this coefficient */ 205 if (Ah != 0) 206 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 207 } else { 208 /* not first scan */ 209 if (Ah != last_bitpos_ptr[coefi] || Al != Ah-1) 210 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 211 } 212 last_bitpos_ptr[coefi] = Al; 213 } 214 } 215 #endif 216 } else { 217 /* For sequential JPEG, all progression parameters must be these: */ 218 if (Ss != 0 || Se != DCTSIZE2-1 || Ah != 0 || Al != 0) 219 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 220 /* Make sure components are not sent twice */ 221 for (ci = 0; ci < ncomps; ci++) { 222 thisi = scanptr->component_index[ci]; 223 if (component_sent[thisi]) 224 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno); 225 component_sent[thisi] = TRUE; 226 } 227 } 228 } 229 230 /* Now verify that everything got sent. */ 231 if (cinfo->progressive_mode) { 232 #ifdef C_PROGRESSIVE_SUPPORTED 233 /* For progressive mode, we only check that at least some DC data 234 * got sent for each component; the spec does not require that all bits 235 * of all coefficients be transmitted. Would it be wiser to enforce 236 * transmission of all coefficient bits?? 237 */ 238 for (ci = 0; ci < cinfo->num_components; ci++) { 239 if (last_bitpos[ci][0] < 0) 240 ERREXIT(cinfo, JERR_MISSING_DATA); 241 } 242 #endif 243 } else { 244 for (ci = 0; ci < cinfo->num_components; ci++) { 245 if (! component_sent[ci]) 246 ERREXIT(cinfo, JERR_MISSING_DATA); 247 } 248 } 249 } 250 251 #endif /* C_MULTISCAN_FILES_SUPPORTED */ 252 253 254 LOCAL void 255 select_scan_parameters (j_compress_ptr cinfo) 256 /* Set up the scan parameters for the current scan */ 257 { 258 int ci; 259 260 #ifdef C_MULTISCAN_FILES_SUPPORTED 261 if (cinfo->scan_info != NULL) { 262 /* Prepare for current scan --- the script is already validated */ 263 my_master_ptr master = (my_master_ptr) cinfo->master; 264 const jpeg_scan_info * scanptr = cinfo->scan_info + master->scan_number; 265 266 cinfo->comps_in_scan = scanptr->comps_in_scan; 267 for (ci = 0; ci < scanptr->comps_in_scan; ci++) { 268 cinfo->cur_comp_info[ci] = 269 &cinfo->comp_info[scanptr->component_index[ci]]; 270 } 271 cinfo->Ss = scanptr->Ss; 272 cinfo->Se = scanptr->Se; 273 cinfo->Ah = scanptr->Ah; 274 cinfo->Al = scanptr->Al; 275 } 276 else 277 #endif 278 { 279 /* Prepare for single sequential-JPEG scan containing all components */ 280 if (cinfo->num_components > MAX_COMPS_IN_SCAN) 281 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components, 282 MAX_COMPS_IN_SCAN); 283 cinfo->comps_in_scan = cinfo->num_components; 284 for (ci = 0; ci < cinfo->num_components; ci++) { 285 cinfo->cur_comp_info[ci] = &cinfo->comp_info[ci]; 286 } 287 cinfo->Ss = 0; 288 cinfo->Se = DCTSIZE2-1; 289 cinfo->Ah = 0; 290 cinfo->Al = 0; 291 } 292 } 293 294 295 LOCAL void 296 per_scan_setup (j_compress_ptr cinfo) 297 /* Do computations that are needed before processing a JPEG scan */ 298 /* cinfo->comps_in_scan and cinfo->cur_comp_info[] are already set */ 299 { 300 int ci, mcublks, tmp; 301 jpeg_component_info *compptr; 302 303 if (cinfo->comps_in_scan == 1) { 304 305 /* Noninterleaved (single-component) scan */ 306 compptr = cinfo->cur_comp_info[0]; 307 308 /* Overall image size in MCUs */ 309 cinfo->MCUs_per_row = compptr->width_in_blocks; 310 cinfo->MCU_rows_in_scan = compptr->height_in_blocks; 311 312 /* For noninterleaved scan, always one block per MCU */ 313 compptr->MCU_width = 1; 314 compptr->MCU_height = 1; 315 compptr->MCU_blocks = 1; 316 compptr->MCU_sample_width = DCTSIZE; 317 compptr->last_col_width = 1; 318 /* For noninterleaved scans, it is convenient to define last_row_height 319 * as the number of block rows present in the last iMCU row. 320 */ 321 tmp = (int) (compptr->height_in_blocks % compptr->v_samp_factor); 322 if (tmp == 0) tmp = compptr->v_samp_factor; 323 compptr->last_row_height = tmp; 324 325 /* Prepare array describing MCU composition */ 326 cinfo->blocks_in_MCU = 1; 327 cinfo->MCU_membership[0] = 0; 328 329 } else { 330 331 /* Interleaved (multi-component) scan */ 332 if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN) 333 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan, 334 MAX_COMPS_IN_SCAN); 335 336 /* Overall image size in MCUs */ 337 cinfo->MCUs_per_row = (JDIMENSION) 338 jdiv_round_up((long) cinfo->image_width, 339 (long) (cinfo->max_h_samp_factor*DCTSIZE)); 340 cinfo->MCU_rows_in_scan = (JDIMENSION) 341 jdiv_round_up((long) cinfo->image_height, 342 (long) (cinfo->max_v_samp_factor*DCTSIZE)); 343 344 cinfo->blocks_in_MCU = 0; 345 346 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 347 compptr = cinfo->cur_comp_info[ci]; 348 /* Sampling factors give # of blocks of component in each MCU */ 349 compptr->MCU_width = compptr->h_samp_factor; 350 compptr->MCU_height = compptr->v_samp_factor; 351 compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height; 352 compptr->MCU_sample_width = compptr->MCU_width * DCTSIZE; 353 /* Figure number of non-dummy blocks in last MCU column & row */ 354 tmp = (int) (compptr->width_in_blocks % compptr->MCU_width); 355 if (tmp == 0) tmp = compptr->MCU_width; 356 compptr->last_col_width = tmp; 357 tmp = (int) (compptr->height_in_blocks % compptr->MCU_height); 358 if (tmp == 0) tmp = compptr->MCU_height; 359 compptr->last_row_height = tmp; 360 /* Prepare array describing MCU composition */ 361 mcublks = compptr->MCU_blocks; 362 if (cinfo->blocks_in_MCU + mcublks > C_MAX_BLOCKS_IN_MCU) 363 ERREXIT(cinfo, JERR_BAD_MCU_SIZE); 364 while (mcublks-- > 0) { 365 cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci; 366 } 367 } 368 369 } 370 371 /* Convert restart specified in rows to actual MCU count. */ 372 /* Note that count must fit in 16 bits, so we provide limiting. */ 373 if (cinfo->restart_in_rows > 0) { 374 long nominal = (long) cinfo->restart_in_rows * (long) cinfo->MCUs_per_row; 375 cinfo->restart_interval = (unsigned int) MIN(nominal, 65535L); 376 } 377 } 378 379 380 /* 381 * Per-pass setup. 382 * This is called at the beginning of each pass. We determine which modules 383 * will be active during this pass and give them appropriate start_pass calls. 384 * We also set is_last_pass to indicate whether any more passes will be 385 * required. 386 */ 387 388 METHODDEF void 389 prepare_for_pass (j_compress_ptr cinfo) 390 { 391 my_master_ptr master = (my_master_ptr) cinfo->master; 392 393 switch (master->pass_type) { 394 case main_pass: 395 /* Initial pass: will collect input data, and do either Huffman 396 * optimization or data output for the first scan. 397 */ 398 select_scan_parameters(cinfo); 399 per_scan_setup(cinfo); 400 if (! cinfo->raw_data_in) { 401 (*cinfo->cconvert->start_pass) (cinfo); 402 (*cinfo->downsample->start_pass) (cinfo); 403 (*cinfo->prep->start_pass) (cinfo, JBUF_PASS_THRU); 404 } 405 (*cinfo->fdct->start_pass) (cinfo); 406 (*cinfo->entropy->start_pass) (cinfo, cinfo->optimize_coding); 407 (*cinfo->coef->start_pass) (cinfo, 408 (master->total_passes > 1 ? 409 JBUF_SAVE_AND_PASS : JBUF_PASS_THRU)); 410 (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU); 411 if (cinfo->optimize_coding) { 412 /* No immediate data output; postpone writing frame/scan headers */ 413 master->pub.call_pass_startup = FALSE; 414 } else { 415 /* Will write frame/scan headers at first jpeg_write_scanlines call */ 416 master->pub.call_pass_startup = TRUE; 417 } 418 break; 419 #ifdef ENTROPY_OPT_SUPPORTED 420 case huff_opt_pass: 421 /* Do Huffman optimization for a scan after the first one. */ 422 select_scan_parameters(cinfo); 423 per_scan_setup(cinfo); 424 if (cinfo->Ss != 0 || cinfo->Ah == 0 || cinfo->arith_code) { 425 (*cinfo->entropy->start_pass) (cinfo, TRUE); 426 (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST); 427 master->pub.call_pass_startup = FALSE; 428 break; 429 } 430 /* Special case: Huffman DC refinement scans need no Huffman table 431 * and therefore we can skip the optimization pass for them. 432 */ 433 master->pass_type = output_pass; 434 master->pass_number++; 435 /*FALLTHROUGH*/ 436 #endif 437 case output_pass: 438 /* Do a data-output pass. */ 439 /* We need not repeat per-scan setup if prior optimization pass did it. */ 440 if (! cinfo->optimize_coding) { 441 select_scan_parameters(cinfo); 442 per_scan_setup(cinfo); 443 } 444 (*cinfo->entropy->start_pass) (cinfo, FALSE); 445 (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST); 446 /* We emit frame/scan headers now */ 447 if (master->scan_number == 0) 448 (*cinfo->marker->write_frame_header) (cinfo); 449 (*cinfo->marker->write_scan_header) (cinfo); 450 master->pub.call_pass_startup = FALSE; 451 break; 452 default: 453 ERREXIT(cinfo, JERR_NOT_COMPILED); 454 } 455 456 master->pub.is_last_pass = (master->pass_number == master->total_passes-1); 457 458 /* Set up progress monitor's pass info if present */ 459 if (cinfo->progress != NULL) { 460 cinfo->progress->completed_passes = master->pass_number; 461 cinfo->progress->total_passes = master->total_passes; 462 } 463 } 464 465 466 /* 467 * Special start-of-pass hook. 468 * This is called by jpeg_write_scanlines if call_pass_startup is TRUE. 469 * In single-pass processing, we need this hook because we don't want to 470 * write frame/scan headers during jpeg_start_compress; we want to let the 471 * application write COM markers etc. between jpeg_start_compress and the 472 * jpeg_write_scanlines loop. 473 * In multi-pass processing, this routine is not used. 474 */ 475 476 METHODDEF void 477 pass_startup (j_compress_ptr cinfo) 478 { 479 cinfo->master->call_pass_startup = FALSE; /* reset flag so call only once */ 480 481 (*cinfo->marker->write_frame_header) (cinfo); 482 (*cinfo->marker->write_scan_header) (cinfo); 483 } 484 485 486 /* 487 * Finish up at end of pass. 488 */ 489 490 METHODDEF void 491 finish_pass_master (j_compress_ptr cinfo) 492 { 493 my_master_ptr master = (my_master_ptr) cinfo->master; 494 495 /* The entropy coder always needs an end-of-pass call, 496 * either to analyze statistics or to flush its output buffer. 497 */ 498 (*cinfo->entropy->finish_pass) (cinfo); 499 500 /* Update state for next pass */ 501 switch (master->pass_type) { 502 case main_pass: 503 /* next pass is either output of scan 0 (after optimization) 504 * or output of scan 1 (if no optimization). 505 */ 506 master->pass_type = output_pass; 507 if (! cinfo->optimize_coding) 508 master->scan_number++; 509 break; 510 case huff_opt_pass: 511 /* next pass is always output of current scan */ 512 master->pass_type = output_pass; 513 break; 514 case output_pass: 515 /* next pass is either optimization or output of next scan */ 516 if (cinfo->optimize_coding) 517 master->pass_type = huff_opt_pass; 518 master->scan_number++; 519 break; 520 } 521 522 master->pass_number++; 523 } 524 525 526 /* 527 * Initialize master compression control. 528 */ 529 530 GLOBAL void 531 jinit_c_master_control (j_compress_ptr cinfo, boolean transcode_only) 532 { 533 my_master_ptr master; 534 535 master = (my_master_ptr) 536 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 537 SIZEOF(my_comp_master)); 538 cinfo->master = (struct jpeg_comp_master *) master; 539 master->pub.prepare_for_pass = prepare_for_pass; 540 master->pub.pass_startup = pass_startup; 541 master->pub.finish_pass = finish_pass_master; 542 master->pub.is_last_pass = FALSE; 543 544 /* Validate parameters, determine derived values */ 545 initial_setup(cinfo); 546 547 if (cinfo->scan_info != NULL) { 548 #ifdef C_MULTISCAN_FILES_SUPPORTED 549 validate_script(cinfo); 550 #else 551 ERREXIT(cinfo, JERR_NOT_COMPILED); 552 #endif 553 } else { 554 cinfo->progressive_mode = FALSE; 555 cinfo->num_scans = 1; 556 } 557 558 if (cinfo->progressive_mode) /* TEMPORARY HACK ??? */ 559 cinfo->optimize_coding = TRUE; /* assume default tables no good for progressive mode */ 560 561 /* Initialize my private state */ 562 if (transcode_only) { 563 /* no main pass in transcoding */ 564 if (cinfo->optimize_coding) 565 master->pass_type = huff_opt_pass; 566 else 567 master->pass_type = output_pass; 568 } else { 569 /* for normal compression, first pass is always this type: */ 570 master->pass_type = main_pass; 571 } 572 master->scan_number = 0; 573 master->pass_number = 0; 574 if (cinfo->optimize_coding) 575 master->total_passes = cinfo->num_scans * 2; 576 else 577 master->total_passes = cinfo->num_scans; 578 }