1/* 2 * jcmaster.c 3 * 4 * This file was part of the Independent JPEG Group's software: 5 * Copyright (C) 1991-1997, Thomas G. Lane. 6 * Modified 2003-2010 by Guido Vollbeding. 7 * libjpeg-turbo Modifications: 8 * Copyright (C) 2010, 2016, D. R. Commander. 9 * For conditions of distribution and use, see the accompanying README.ijg 10 * file. 11 * 12 * This file contains master control logic for the JPEG compressor. 13 * These routines are concerned with parameter validation, initial setup, 14 * and inter-pass control (determining the number of passes and the work 15 * to be done in each pass). 16 */ 17 18#define JPEG_INTERNALS 19#include "jinclude.h" 20#include "jpeglib.h" 21#include "jpegcomp.h" 22#include "jconfigint.h" 23 24 25/* Private state */ 26 27typedef enum { 28 main_pass, /* input data, also do first output step */ 29 huff_opt_pass, /* Huffman code optimization pass */ 30 output_pass /* data output pass */ 31} c_pass_type; 32 33typedef struct { 34 struct jpeg_comp_master pub; /* public fields */ 35 36 c_pass_type pass_type; /* the type of the current pass */ 37 38 int pass_number; /* # of passes completed */ 39 int total_passes; /* total # of passes needed */ 40 41 int scan_number; /* current index in scan_info[] */ 42 43 /* 44 * This is here so we can add libjpeg-turbo version/build information to the 45 * global string table without introducing a new global symbol. Adding this 46 * information to the global string table allows one to examine a binary 47 * object and determine which version of libjpeg-turbo it was built from or 48 * linked against. 49 */ 50 const char *jpeg_version; 51 52} my_comp_master; 53 54typedef my_comp_master *my_master_ptr; 55 56 57/* 58 * Support routines that do various essential calculations. 59 */ 60 61#if JPEG_LIB_VERSION >= 70 62/* 63 * Compute JPEG image dimensions and related values. 64 * NOTE: this is exported for possible use by application. 65 * Hence it mustn't do anything that can't be done twice. 66 */ 67 68GLOBAL(void) 69jpeg_calc_jpeg_dimensions (j_compress_ptr cinfo) 70/* Do computations that are needed before master selection phase */ 71{ 72 /* Hardwire it to "no scaling" */ 73 cinfo->jpeg_width = cinfo->image_width; 74 cinfo->jpeg_height = cinfo->image_height; 75 cinfo->min_DCT_h_scaled_size = DCTSIZE; 76 cinfo->min_DCT_v_scaled_size = DCTSIZE; 77} 78#endif 79 80 81LOCAL(void) 82initial_setup (j_compress_ptr cinfo, boolean transcode_only) 83/* Do computations that are needed before master selection phase */ 84{ 85 int ci; 86 jpeg_component_info *compptr; 87 long samplesperrow; 88 JDIMENSION jd_samplesperrow; 89 90#if JPEG_LIB_VERSION >= 70 91#if JPEG_LIB_VERSION >= 80 92 if (!transcode_only) 93#endif 94 jpeg_calc_jpeg_dimensions(cinfo); 95#endif 96 97 /* Sanity check on image dimensions */ 98 if (cinfo->_jpeg_height <= 0 || cinfo->_jpeg_width <= 0 99 || cinfo->num_components <= 0 || cinfo->input_components <= 0) 100 ERREXIT(cinfo, JERR_EMPTY_IMAGE); 101 102 /* Make sure image isn't bigger than I can handle */ 103 if ((long) cinfo->_jpeg_height > (long) JPEG_MAX_DIMENSION || 104 (long) cinfo->_jpeg_width > (long) JPEG_MAX_DIMENSION) 105 ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION); 106 107 /* Width of an input scanline must be representable as JDIMENSION. */ 108 samplesperrow = (long) cinfo->image_width * (long) cinfo->input_components; 109 jd_samplesperrow = (JDIMENSION) samplesperrow; 110 if ((long) jd_samplesperrow != samplesperrow) 111 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); 112 113 /* For now, precision must match compiled-in value... */ 114 if (cinfo->data_precision != BITS_IN_JSAMPLE) 115 ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision); 116 117 /* Check that number of components won't exceed internal array sizes */ 118 if (cinfo->num_components > MAX_COMPONENTS) 119 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components, 120 MAX_COMPONENTS); 121 122 /* Compute maximum sampling factors; check factor validity */ 123 cinfo->max_h_samp_factor = 1; 124 cinfo->max_v_samp_factor = 1; 125 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 126 ci++, compptr++) { 127 if (compptr->h_samp_factor<=0 || compptr->h_samp_factor>MAX_SAMP_FACTOR || 128 compptr->v_samp_factor<=0 || compptr->v_samp_factor>MAX_SAMP_FACTOR) 129 ERREXIT(cinfo, JERR_BAD_SAMPLING); 130 cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor, 131 compptr->h_samp_factor); 132 cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor, 133 compptr->v_samp_factor); 134 } 135 136 /* Compute dimensions of components */ 137 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 138 ci++, compptr++) { 139 /* Fill in the correct component_index value; don't rely on application */ 140 compptr->component_index = ci; 141 /* For compression, we never do DCT scaling. */ 142#if JPEG_LIB_VERSION >= 70 143 compptr->DCT_h_scaled_size = compptr->DCT_v_scaled_size = DCTSIZE; 144#else 145 compptr->DCT_scaled_size = DCTSIZE; 146#endif 147 /* Size in DCT blocks */ 148 compptr->width_in_blocks = (JDIMENSION) 149 jdiv_round_up((long) cinfo->_jpeg_width * (long) compptr->h_samp_factor, 150 (long) (cinfo->max_h_samp_factor * DCTSIZE)); 151 compptr->height_in_blocks = (JDIMENSION) 152 jdiv_round_up((long) cinfo->_jpeg_height * (long) compptr->v_samp_factor, 153 (long) (cinfo->max_v_samp_factor * DCTSIZE)); 154 /* Size in samples */ 155 compptr->downsampled_width = (JDIMENSION) 156 jdiv_round_up((long) cinfo->_jpeg_width * (long) compptr->h_samp_factor, 157 (long) cinfo->max_h_samp_factor); 158 compptr->downsampled_height = (JDIMENSION) 159 jdiv_round_up((long) cinfo->_jpeg_height * (long) compptr->v_samp_factor, 160 (long) cinfo->max_v_samp_factor); 161 /* Mark component needed (this flag isn't actually used for compression) */ 162 compptr->component_needed = TRUE; 163 } 164 165 /* Compute number of fully interleaved MCU rows (number of times that 166 * main controller will call coefficient controller). 167 */ 168 cinfo->total_iMCU_rows = (JDIMENSION) 169 jdiv_round_up((long) cinfo->_jpeg_height, 170 (long) (cinfo->max_v_samp_factor*DCTSIZE)); 171} 172 173 174#ifdef C_MULTISCAN_FILES_SUPPORTED 175 176LOCAL(void) 177validate_script (j_compress_ptr cinfo) 178/* Verify that the scan script in cinfo->scan_info[] is valid; also 179 * determine whether it uses progressive JPEG, and set cinfo->progressive_mode. 180 */ 181{ 182 const jpeg_scan_info *scanptr; 183 int scanno, ncomps, ci, coefi, thisi; 184 int Ss, Se, Ah, Al; 185 boolean component_sent[MAX_COMPONENTS]; 186#ifdef C_PROGRESSIVE_SUPPORTED 187 int *last_bitpos_ptr; 188 int last_bitpos[MAX_COMPONENTS][DCTSIZE2]; 189 /* -1 until that coefficient has been seen; then last Al for it */ 190#endif 191 192 if (cinfo->num_scans <= 0) 193 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, 0); 194 195 /* For sequential JPEG, all scans must have Ss=0, Se=DCTSIZE2-1; 196 * for progressive JPEG, no scan can have this. 197 */ 198 scanptr = cinfo->scan_info; 199 if (scanptr->Ss != 0 || scanptr->Se != DCTSIZE2-1) { 200#ifdef C_PROGRESSIVE_SUPPORTED 201 cinfo->progressive_mode = TRUE; 202 last_bitpos_ptr = & last_bitpos[0][0]; 203 for (ci = 0; ci < cinfo->num_components; ci++) 204 for (coefi = 0; coefi < DCTSIZE2; coefi++) 205 *last_bitpos_ptr++ = -1; 206#else 207 ERREXIT(cinfo, JERR_NOT_COMPILED); 208#endif 209 } else { 210 cinfo->progressive_mode = FALSE; 211 for (ci = 0; ci < cinfo->num_components; ci++) 212 component_sent[ci] = FALSE; 213 } 214 215 for (scanno = 1; scanno <= cinfo->num_scans; scanptr++, scanno++) { 216 /* Validate component indexes */ 217 ncomps = scanptr->comps_in_scan; 218 if (ncomps <= 0 || ncomps > MAX_COMPS_IN_SCAN) 219 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, ncomps, MAX_COMPS_IN_SCAN); 220 for (ci = 0; ci < ncomps; ci++) { 221 thisi = scanptr->component_index[ci]; 222 if (thisi < 0 || thisi >= cinfo->num_components) 223 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno); 224 /* Components must appear in SOF order within each scan */ 225 if (ci > 0 && thisi <= scanptr->component_index[ci-1]) 226 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno); 227 } 228 /* Validate progression parameters */ 229 Ss = scanptr->Ss; 230 Se = scanptr->Se; 231 Ah = scanptr->Ah; 232 Al = scanptr->Al; 233 if (cinfo->progressive_mode) { 234#ifdef C_PROGRESSIVE_SUPPORTED 235 /* The JPEG spec simply gives the ranges 0..13 for Ah and Al, but that 236 * seems wrong: the upper bound ought to depend on data precision. 237 * Perhaps they really meant 0..N+1 for N-bit precision. 238 * Here we allow 0..10 for 8-bit data; Al larger than 10 results in 239 * out-of-range reconstructed DC values during the first DC scan, 240 * which might cause problems for some decoders. 241 */ 242#if BITS_IN_JSAMPLE == 8 243#define MAX_AH_AL 10 244#else 245#define MAX_AH_AL 13 246#endif 247 if (Ss < 0 || Ss >= DCTSIZE2 || Se < Ss || Se >= DCTSIZE2 || 248 Ah < 0 || Ah > MAX_AH_AL || Al < 0 || Al > MAX_AH_AL) 249 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 250 if (Ss == 0) { 251 if (Se != 0) /* DC and AC together not OK */ 252 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 253 } else { 254 if (ncomps != 1) /* AC scans must be for only one component */ 255 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 256 } 257 for (ci = 0; ci < ncomps; ci++) { 258 last_bitpos_ptr = & last_bitpos[scanptr->component_index[ci]][0]; 259 if (Ss != 0 && last_bitpos_ptr[0] < 0) /* AC without prior DC scan */ 260 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 261 for (coefi = Ss; coefi <= Se; coefi++) { 262 if (last_bitpos_ptr[coefi] < 0) { 263 /* first scan of this coefficient */ 264 if (Ah != 0) 265 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 266 } else { 267 /* not first scan */ 268 if (Ah != last_bitpos_ptr[coefi] || Al != Ah-1) 269 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 270 } 271 last_bitpos_ptr[coefi] = Al; 272 } 273 } 274#endif 275 } else { 276 /* For sequential JPEG, all progression parameters must be these: */ 277 if (Ss != 0 || Se != DCTSIZE2-1 || Ah != 0 || Al != 0) 278 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 279 /* Make sure components are not sent twice */ 280 for (ci = 0; ci < ncomps; ci++) { 281 thisi = scanptr->component_index[ci]; 282 if (component_sent[thisi]) 283 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno); 284 component_sent[thisi] = TRUE; 285 } 286 } 287 } 288 289 /* Now verify that everything got sent. */ 290 if (cinfo->progressive_mode) { 291#ifdef C_PROGRESSIVE_SUPPORTED 292 /* For progressive mode, we only check that at least some DC data 293 * got sent for each component; the spec does not require that all bits 294 * of all coefficients be transmitted. Would it be wiser to enforce 295 * transmission of all coefficient bits?? 296 */ 297 for (ci = 0; ci < cinfo->num_components; ci++) { 298 if (last_bitpos[ci][0] < 0) 299 ERREXIT(cinfo, JERR_MISSING_DATA); 300 } 301#endif 302 } else { 303 for (ci = 0; ci < cinfo->num_components; ci++) { 304 if (! component_sent[ci]) 305 ERREXIT(cinfo, JERR_MISSING_DATA); 306 } 307 } 308} 309 310#endif /* C_MULTISCAN_FILES_SUPPORTED */ 311 312 313LOCAL(void) 314select_scan_parameters (j_compress_ptr cinfo) 315/* Set up the scan parameters for the current scan */ 316{ 317 int ci; 318 319#ifdef C_MULTISCAN_FILES_SUPPORTED 320 if (cinfo->scan_info != NULL) { 321 /* Prepare for current scan --- the script is already validated */ 322 my_master_ptr master = (my_master_ptr) cinfo->master; 323 const jpeg_scan_info *scanptr = cinfo->scan_info + master->scan_number; 324 325 cinfo->comps_in_scan = scanptr->comps_in_scan; 326 for (ci = 0; ci < scanptr->comps_in_scan; ci++) { 327 cinfo->cur_comp_info[ci] = 328 &cinfo->comp_info[scanptr->component_index[ci]]; 329 } 330 cinfo->Ss = scanptr->Ss; 331 cinfo->Se = scanptr->Se; 332 cinfo->Ah = scanptr->Ah; 333 cinfo->Al = scanptr->Al; 334 } 335 else 336#endif 337 { 338 /* Prepare for single sequential-JPEG scan containing all components */ 339 if (cinfo->num_components > MAX_COMPS_IN_SCAN) 340 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components, 341 MAX_COMPS_IN_SCAN); 342 cinfo->comps_in_scan = cinfo->num_components; 343 for (ci = 0; ci < cinfo->num_components; ci++) { 344 cinfo->cur_comp_info[ci] = &cinfo->comp_info[ci]; 345 } 346 cinfo->Ss = 0; 347 cinfo->Se = DCTSIZE2-1; 348 cinfo->Ah = 0; 349 cinfo->Al = 0; 350 } 351} 352 353 354LOCAL(void) 355per_scan_setup (j_compress_ptr cinfo) 356/* Do computations that are needed before processing a JPEG scan */ 357/* cinfo->comps_in_scan and cinfo->cur_comp_info[] are already set */ 358{ 359 int ci, mcublks, tmp; 360 jpeg_component_info *compptr; 361 362 if (cinfo->comps_in_scan == 1) { 363 364 /* Noninterleaved (single-component) scan */ 365 compptr = cinfo->cur_comp_info[0]; 366 367 /* Overall image size in MCUs */ 368 cinfo->MCUs_per_row = compptr->width_in_blocks; 369 cinfo->MCU_rows_in_scan = compptr->height_in_blocks; 370 371 /* For noninterleaved scan, always one block per MCU */ 372 compptr->MCU_width = 1; 373 compptr->MCU_height = 1; 374 compptr->MCU_blocks = 1; 375 compptr->MCU_sample_width = DCTSIZE; 376 compptr->last_col_width = 1; 377 /* For noninterleaved scans, it is convenient to define last_row_height 378 * as the number of block rows present in the last iMCU row. 379 */ 380 tmp = (int) (compptr->height_in_blocks % compptr->v_samp_factor); 381 if (tmp == 0) tmp = compptr->v_samp_factor; 382 compptr->last_row_height = tmp; 383 384 /* Prepare array describing MCU composition */ 385 cinfo->blocks_in_MCU = 1; 386 cinfo->MCU_membership[0] = 0; 387 388 } else { 389 390 /* Interleaved (multi-component) scan */ 391 if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN) 392 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan, 393 MAX_COMPS_IN_SCAN); 394 395 /* Overall image size in MCUs */ 396 cinfo->MCUs_per_row = (JDIMENSION) 397 jdiv_round_up((long) cinfo->_jpeg_width, 398 (long) (cinfo->max_h_samp_factor*DCTSIZE)); 399 cinfo->MCU_rows_in_scan = (JDIMENSION) 400 jdiv_round_up((long) cinfo->_jpeg_height, 401 (long) (cinfo->max_v_samp_factor*DCTSIZE)); 402 403 cinfo->blocks_in_MCU = 0; 404 405 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 406 compptr = cinfo->cur_comp_info[ci]; 407 /* Sampling factors give # of blocks of component in each MCU */ 408 compptr->MCU_width = compptr->h_samp_factor; 409 compptr->MCU_height = compptr->v_samp_factor; 410 compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height; 411 compptr->MCU_sample_width = compptr->MCU_width * DCTSIZE; 412 /* Figure number of non-dummy blocks in last MCU column & row */ 413 tmp = (int) (compptr->width_in_blocks % compptr->MCU_width); 414 if (tmp == 0) tmp = compptr->MCU_width; 415 compptr->last_col_width = tmp; 416 tmp = (int) (compptr->height_in_blocks % compptr->MCU_height); 417 if (tmp == 0) tmp = compptr->MCU_height; 418 compptr->last_row_height = tmp; 419 /* Prepare array describing MCU composition */ 420 mcublks = compptr->MCU_blocks; 421 if (cinfo->blocks_in_MCU + mcublks > C_MAX_BLOCKS_IN_MCU) 422 ERREXIT(cinfo, JERR_BAD_MCU_SIZE); 423 while (mcublks-- > 0) { 424 cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci; 425 } 426 } 427 428 } 429 430 /* Convert restart specified in rows to actual MCU count. */ 431 /* Note that count must fit in 16 bits, so we provide limiting. */ 432 if (cinfo->restart_in_rows > 0) { 433 long nominal = (long) cinfo->restart_in_rows * (long) cinfo->MCUs_per_row; 434 cinfo->restart_interval = (unsigned int) MIN(nominal, 65535L); 435 } 436} 437 438 439/* 440 * Per-pass setup. 441 * This is called at the beginning of each pass. We determine which modules 442 * will be active during this pass and give them appropriate start_pass calls. 443 * We also set is_last_pass to indicate whether any more passes will be 444 * required. 445 */ 446 447METHODDEF(void) 448prepare_for_pass (j_compress_ptr cinfo) 449{ 450 my_master_ptr master = (my_master_ptr) cinfo->master; 451 452 switch (master->pass_type) { 453 case main_pass: 454 /* Initial pass: will collect input data, and do either Huffman 455 * optimization or data output for the first scan. 456 */ 457 select_scan_parameters(cinfo); 458 per_scan_setup(cinfo); 459 if (! cinfo->raw_data_in) { 460 (*cinfo->cconvert->start_pass) (cinfo); 461 (*cinfo->downsample->start_pass) (cinfo); 462 (*cinfo->prep->start_pass) (cinfo, JBUF_PASS_THRU); 463 } 464 (*cinfo->fdct->start_pass) (cinfo); 465 (*cinfo->entropy->start_pass) (cinfo, cinfo->optimize_coding); 466 (*cinfo->coef->start_pass) (cinfo, 467 (master->total_passes > 1 ? 468 JBUF_SAVE_AND_PASS : JBUF_PASS_THRU)); 469 (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU); 470 if (cinfo->optimize_coding) { 471 /* No immediate data output; postpone writing frame/scan headers */ 472 master->pub.call_pass_startup = FALSE; 473 } else { 474 /* Will write frame/scan headers at first jpeg_write_scanlines call */ 475 master->pub.call_pass_startup = TRUE; 476 } 477 break; 478#ifdef ENTROPY_OPT_SUPPORTED 479 case huff_opt_pass: 480 /* Do Huffman optimization for a scan after the first one. */ 481 select_scan_parameters(cinfo); 482 per_scan_setup(cinfo); 483 if (cinfo->Ss != 0 || cinfo->Ah == 0 || cinfo->arith_code) { 484 (*cinfo->entropy->start_pass) (cinfo, TRUE); 485 (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST); 486 master->pub.call_pass_startup = FALSE; 487 break; 488 } 489 /* Special case: Huffman DC refinement scans need no Huffman table 490 * and therefore we can skip the optimization pass for them. 491 */ 492 master->pass_type = output_pass; 493 master->pass_number++; 494 /*FALLTHROUGH*/ 495#endif 496 case output_pass: 497 /* Do a data-output pass. */ 498 /* We need not repeat per-scan setup if prior optimization pass did it. */ 499 if (! cinfo->optimize_coding) { 500 select_scan_parameters(cinfo); 501 per_scan_setup(cinfo); 502 } 503 (*cinfo->entropy->start_pass) (cinfo, FALSE); 504 (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST); 505 /* We emit frame/scan headers now */ 506 if (master->scan_number == 0) 507 (*cinfo->marker->write_frame_header) (cinfo); 508 (*cinfo->marker->write_scan_header) (cinfo); 509 master->pub.call_pass_startup = FALSE; 510 break; 511 default: 512 ERREXIT(cinfo, JERR_NOT_COMPILED); 513 } 514 515 master->pub.is_last_pass = (master->pass_number == master->total_passes-1); 516 517 /* Set up progress monitor's pass info if present */ 518 if (cinfo->progress != NULL) { 519 cinfo->progress->completed_passes = master->pass_number; 520 cinfo->progress->total_passes = master->total_passes; 521 } 522} 523 524 525/* 526 * Special start-of-pass hook. 527 * This is called by jpeg_write_scanlines if call_pass_startup is TRUE. 528 * In single-pass processing, we need this hook because we don't want to 529 * write frame/scan headers during jpeg_start_compress; we want to let the 530 * application write COM markers etc. between jpeg_start_compress and the 531 * jpeg_write_scanlines loop. 532 * In multi-pass processing, this routine is not used. 533 */ 534 535METHODDEF(void) 536pass_startup (j_compress_ptr cinfo) 537{ 538 cinfo->master->call_pass_startup = FALSE; /* reset flag so call only once */ 539 540 (*cinfo->marker->write_frame_header) (cinfo); 541 (*cinfo->marker->write_scan_header) (cinfo); 542} 543 544 545/* 546 * Finish up at end of pass. 547 */ 548 549METHODDEF(void) 550finish_pass_master (j_compress_ptr cinfo) 551{ 552 my_master_ptr master = (my_master_ptr) cinfo->master; 553 554 /* The entropy coder always needs an end-of-pass call, 555 * either to analyze statistics or to flush its output buffer. 556 */ 557 (*cinfo->entropy->finish_pass) (cinfo); 558 559 /* Update state for next pass */ 560 switch (master->pass_type) { 561 case main_pass: 562 /* next pass is either output of scan 0 (after optimization) 563 * or output of scan 1 (if no optimization). 564 */ 565 master->pass_type = output_pass; 566 if (! cinfo->optimize_coding) 567 master->scan_number++; 568 break; 569 case huff_opt_pass: 570 /* next pass is always output of current scan */ 571 master->pass_type = output_pass; 572 break; 573 case output_pass: 574 /* next pass is either optimization or output of next scan */ 575 if (cinfo->optimize_coding) 576 master->pass_type = huff_opt_pass; 577 master->scan_number++; 578 break; 579 } 580 581 master->pass_number++; 582} 583 584 585/* 586 * Initialize master compression control. 587 */ 588 589GLOBAL(void) 590jinit_c_master_control (j_compress_ptr cinfo, boolean transcode_only) 591{ 592 my_master_ptr master; 593 594 master = (my_master_ptr) 595 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 596 sizeof(my_comp_master)); 597 cinfo->master = (struct jpeg_comp_master *) master; 598 master->pub.prepare_for_pass = prepare_for_pass; 599 master->pub.pass_startup = pass_startup; 600 master->pub.finish_pass = finish_pass_master; 601 master->pub.is_last_pass = FALSE; 602 603 /* Validate parameters, determine derived values */ 604 initial_setup(cinfo, transcode_only); 605 606 if (cinfo->scan_info != NULL) { 607#ifdef C_MULTISCAN_FILES_SUPPORTED 608 validate_script(cinfo); 609#else 610 ERREXIT(cinfo, JERR_NOT_COMPILED); 611#endif 612 } else { 613 cinfo->progressive_mode = FALSE; 614 cinfo->num_scans = 1; 615 } 616 617 if (cinfo->progressive_mode && !cinfo->arith_code) /* TEMPORARY HACK ??? */ 618 cinfo->optimize_coding = TRUE; /* assume default tables no good for progressive mode */ 619 620 /* Initialize my private state */ 621 if (transcode_only) { 622 /* no main pass in transcoding */ 623 if (cinfo->optimize_coding) 624 master->pass_type = huff_opt_pass; 625 else 626 master->pass_type = output_pass; 627 } else { 628 /* for normal compression, first pass is always this type: */ 629 master->pass_type = main_pass; 630 } 631 master->scan_number = 0; 632 master->pass_number = 0; 633 if (cinfo->optimize_coding) 634 master->total_passes = cinfo->num_scans * 2; 635 else 636 master->total_passes = cinfo->num_scans; 637 638 master->jpeg_version = PACKAGE_NAME " version " VERSION " (build " BUILD ")"; 639} 640