1 /* 2 * jcmaster.c 3 * 4 * Copyright (C) 1991-1997, Thomas G. Lane. 5 * Modified 2003-2011 by Guido Vollbeding. 6 * This file is part of the Independent JPEG Group's software. 7 * For conditions of distribution and use, see the accompanying README file. 8 * 9 * This file contains master control logic for the JPEG compressor. 10 * These routines are concerned with parameter validation, initial setup, 11 * and inter-pass control (determining the number of passes and the work 12 * to be done in each pass). 13 */ 14 15 #define JPEG_INTERNALS 16 #include "jinclude.h" 17 #include "jpeglib.h" 18 19 20 /* Private state */ 21 22 typedef enum { 23 main_pass, /* input data, also do first output step */ 24 huff_opt_pass, /* Huffman code optimization pass */ 25 output_pass /* data output pass */ 26 } c_pass_type; 27 28 typedef struct { 29 struct jpeg_comp_master pub; /* public fields */ 30 31 c_pass_type pass_type; /* the type of the current pass */ 32 33 int pass_number; /* # of passes completed */ 34 int total_passes; /* total # of passes needed */ 35 36 int scan_number; /* current index in scan_info[] */ 37 } my_comp_master; 38 39 typedef my_comp_master * my_master_ptr; 40 41 42 /* 43 * Support routines that do various essential calculations. 44 */ 45 46 /* 47 * Compute JPEG image dimensions and related values. 48 * NOTE: this is exported for possible use by application. 49 * Hence it mustn't do anything that can't be done twice. 50 */ 51 52 GLOBAL(void) 53 jpeg_calc_jpeg_dimensions (j_compress_ptr cinfo) 54 /* Do computations that are needed before master selection phase */ 55 { 56 #ifdef DCT_SCALING_SUPPORTED 57 58 /* Sanity check on input image dimensions to prevent overflow in 59 * following calculation. 60 * We do check jpeg_width and jpeg_height in initial_setup below, 61 * but image_width and image_height can come from arbitrary data, 62 * and we need some space for multiplication by block_size. 63 */ 64 if (((long) cinfo->image_width >> 24) || ((long) cinfo->image_height >> 24)) 65 ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION); 66 67 /* Compute actual JPEG image dimensions and DCT scaling choices. */ 68 if (cinfo->scale_num >= cinfo->scale_denom * cinfo->block_size) { 69 /* Provide block_size/1 scaling */ 70 cinfo->jpeg_width = cinfo->image_width * cinfo->block_size; 71 cinfo->jpeg_height = cinfo->image_height * cinfo->block_size; 72 cinfo->min_DCT_h_scaled_size = 1; 73 cinfo->min_DCT_v_scaled_size = 1; 74 } else if (cinfo->scale_num * 2 >= cinfo->scale_denom * cinfo->block_size) { 75 /* Provide block_size/2 scaling */ 76 cinfo->jpeg_width = (JDIMENSION) 77 jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 2L); 78 cinfo->jpeg_height = (JDIMENSION) 79 jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 2L); 80 cinfo->min_DCT_h_scaled_size = 2; 81 cinfo->min_DCT_v_scaled_size = 2; 82 } else if (cinfo->scale_num * 3 >= cinfo->scale_denom * cinfo->block_size) { 83 /* Provide block_size/3 scaling */ 84 cinfo->jpeg_width = (JDIMENSION) 85 jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 3L); 86 cinfo->jpeg_height = (JDIMENSION) 87 jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 3L); 88 cinfo->min_DCT_h_scaled_size = 3; 89 cinfo->min_DCT_v_scaled_size = 3; 90 } else if (cinfo->scale_num * 4 >= cinfo->scale_denom * cinfo->block_size) { 91 /* Provide block_size/4 scaling */ 92 cinfo->jpeg_width = (JDIMENSION) 93 jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 4L); 94 cinfo->jpeg_height = (JDIMENSION) 95 jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 4L); 96 cinfo->min_DCT_h_scaled_size = 4; 97 cinfo->min_DCT_v_scaled_size = 4; 98 } else if (cinfo->scale_num * 5 >= cinfo->scale_denom * cinfo->block_size) { 99 /* Provide block_size/5 scaling */ 100 cinfo->jpeg_width = (JDIMENSION) 101 jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 5L); 102 cinfo->jpeg_height = (JDIMENSION) 103 jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 5L); 104 cinfo->min_DCT_h_scaled_size = 5; 105 cinfo->min_DCT_v_scaled_size = 5; 106 } else if (cinfo->scale_num * 6 >= cinfo->scale_denom * cinfo->block_size) { 107 /* Provide block_size/6 scaling */ 108 cinfo->jpeg_width = (JDIMENSION) 109 jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 6L); 110 cinfo->jpeg_height = (JDIMENSION) 111 jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 6L); 112 cinfo->min_DCT_h_scaled_size = 6; 113 cinfo->min_DCT_v_scaled_size = 6; 114 } else if (cinfo->scale_num * 7 >= cinfo->scale_denom * cinfo->block_size) { 115 /* Provide block_size/7 scaling */ 116 cinfo->jpeg_width = (JDIMENSION) 117 jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 7L); 118 cinfo->jpeg_height = (JDIMENSION) 119 jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 7L); 120 cinfo->min_DCT_h_scaled_size = 7; 121 cinfo->min_DCT_v_scaled_size = 7; 122 } else if (cinfo->scale_num * 8 >= cinfo->scale_denom * cinfo->block_size) { 123 /* Provide block_size/8 scaling */ 124 cinfo->jpeg_width = (JDIMENSION) 125 jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 8L); 126 cinfo->jpeg_height = (JDIMENSION) 127 jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 8L); 128 cinfo->min_DCT_h_scaled_size = 8; 129 cinfo->min_DCT_v_scaled_size = 8; 130 } else if (cinfo->scale_num * 9 >= cinfo->scale_denom * cinfo->block_size) { 131 /* Provide block_size/9 scaling */ 132 cinfo->jpeg_width = (JDIMENSION) 133 jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 9L); 134 cinfo->jpeg_height = (JDIMENSION) 135 jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 9L); 136 cinfo->min_DCT_h_scaled_size = 9; 137 cinfo->min_DCT_v_scaled_size = 9; 138 } else if (cinfo->scale_num * 10 >= cinfo->scale_denom * cinfo->block_size) { 139 /* Provide block_size/10 scaling */ 140 cinfo->jpeg_width = (JDIMENSION) 141 jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 10L); 142 cinfo->jpeg_height = (JDIMENSION) 143 jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 10L); 144 cinfo->min_DCT_h_scaled_size = 10; 145 cinfo->min_DCT_v_scaled_size = 10; 146 } else if (cinfo->scale_num * 11 >= cinfo->scale_denom * cinfo->block_size) { 147 /* Provide block_size/11 scaling */ 148 cinfo->jpeg_width = (JDIMENSION) 149 jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 11L); 150 cinfo->jpeg_height = (JDIMENSION) 151 jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 11L); 152 cinfo->min_DCT_h_scaled_size = 11; 153 cinfo->min_DCT_v_scaled_size = 11; 154 } else if (cinfo->scale_num * 12 >= cinfo->scale_denom * cinfo->block_size) { 155 /* Provide block_size/12 scaling */ 156 cinfo->jpeg_width = (JDIMENSION) 157 jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 12L); 158 cinfo->jpeg_height = (JDIMENSION) 159 jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 12L); 160 cinfo->min_DCT_h_scaled_size = 12; 161 cinfo->min_DCT_v_scaled_size = 12; 162 } else if (cinfo->scale_num * 13 >= cinfo->scale_denom * cinfo->block_size) { 163 /* Provide block_size/13 scaling */ 164 cinfo->jpeg_width = (JDIMENSION) 165 jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 13L); 166 cinfo->jpeg_height = (JDIMENSION) 167 jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 13L); 168 cinfo->min_DCT_h_scaled_size = 13; 169 cinfo->min_DCT_v_scaled_size = 13; 170 } else if (cinfo->scale_num * 14 >= cinfo->scale_denom * cinfo->block_size) { 171 /* Provide block_size/14 scaling */ 172 cinfo->jpeg_width = (JDIMENSION) 173 jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 14L); 174 cinfo->jpeg_height = (JDIMENSION) 175 jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 14L); 176 cinfo->min_DCT_h_scaled_size = 14; 177 cinfo->min_DCT_v_scaled_size = 14; 178 } else if (cinfo->scale_num * 15 >= cinfo->scale_denom * cinfo->block_size) { 179 /* Provide block_size/15 scaling */ 180 cinfo->jpeg_width = (JDIMENSION) 181 jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 15L); 182 cinfo->jpeg_height = (JDIMENSION) 183 jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 15L); 184 cinfo->min_DCT_h_scaled_size = 15; 185 cinfo->min_DCT_v_scaled_size = 15; 186 } else { 187 /* Provide block_size/16 scaling */ 188 cinfo->jpeg_width = (JDIMENSION) 189 jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 16L); 190 cinfo->jpeg_height = (JDIMENSION) 191 jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 16L); 192 cinfo->min_DCT_h_scaled_size = 16; 193 cinfo->min_DCT_v_scaled_size = 16; 194 } 195 196 #else /* !DCT_SCALING_SUPPORTED */ 197 198 /* Hardwire it to "no scaling" */ 199 cinfo->jpeg_width = cinfo->image_width; 200 cinfo->jpeg_height = cinfo->image_height; 201 cinfo->min_DCT_h_scaled_size = DCTSIZE; 202 cinfo->min_DCT_v_scaled_size = DCTSIZE; 203 204 #endif /* DCT_SCALING_SUPPORTED */ 205 } 206 207 208 LOCAL(void) 209 jpeg_calc_trans_dimensions (j_compress_ptr cinfo) 210 { 211 if (cinfo->min_DCT_h_scaled_size != cinfo->min_DCT_v_scaled_size) 212 ERREXIT2(cinfo, JERR_BAD_DCTSIZE, 213 cinfo->min_DCT_h_scaled_size, cinfo->min_DCT_v_scaled_size); 214 215 cinfo->block_size = cinfo->min_DCT_h_scaled_size; 216 } 217 218 219 LOCAL(void) 220 initial_setup (j_compress_ptr cinfo, boolean transcode_only) 221 /* Do computations that are needed before master selection phase */ 222 { 223 int ci, ssize; 224 jpeg_component_info *compptr; 225 long samplesperrow; 226 JDIMENSION jd_samplesperrow; 227 228 if (transcode_only) 229 jpeg_calc_trans_dimensions(cinfo); 230 else 231 jpeg_calc_jpeg_dimensions(cinfo); 232 233 /* Sanity check on block_size */ 234 if (cinfo->block_size < 1 || cinfo->block_size > 16) 235 ERREXIT2(cinfo, JERR_BAD_DCTSIZE, cinfo->block_size, cinfo->block_size); 236 237 /* Derive natural_order from block_size */ 238 switch (cinfo->block_size) { 239 case 2: cinfo->natural_order = jpeg_natural_order2; break; 240 case 3: cinfo->natural_order = jpeg_natural_order3; break; 241 case 4: cinfo->natural_order = jpeg_natural_order4; break; 242 case 5: cinfo->natural_order = jpeg_natural_order5; break; 243 case 6: cinfo->natural_order = jpeg_natural_order6; break; 244 case 7: cinfo->natural_order = jpeg_natural_order7; break; 245 default: cinfo->natural_order = jpeg_natural_order; break; 246 } 247 248 /* Derive lim_Se from block_size */ 249 cinfo->lim_Se = cinfo->block_size < DCTSIZE ? 250 cinfo->block_size * cinfo->block_size - 1 : DCTSIZE2-1; 251 252 /* Sanity check on image dimensions */ 253 if (cinfo->jpeg_height <= 0 || cinfo->jpeg_width <= 0 || 254 cinfo->num_components <= 0 || cinfo->input_components <= 0) 255 ERREXIT(cinfo, JERR_EMPTY_IMAGE); 256 257 /* Make sure image isn't bigger than I can handle */ 258 if ((long) cinfo->jpeg_height > (long) JPEG_MAX_DIMENSION || 259 (long) cinfo->jpeg_width > (long) JPEG_MAX_DIMENSION) 260 ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION); 261 262 /* Width of an input scanline must be representable as JDIMENSION. */ 263 samplesperrow = (long) cinfo->image_width * (long) cinfo->input_components; 264 jd_samplesperrow = (JDIMENSION) samplesperrow; 265 if ((long) jd_samplesperrow != samplesperrow) 266 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); 267 268 /* For now, precision must match compiled-in value... */ 269 if (cinfo->data_precision != BITS_IN_JSAMPLE) 270 ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision); 271 272 /* Check that number of components won't exceed internal array sizes */ 273 if (cinfo->num_components > MAX_COMPONENTS) 274 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components, 275 MAX_COMPONENTS); 276 277 /* Compute maximum sampling factors; check factor validity */ 278 cinfo->max_h_samp_factor = 1; 279 cinfo->max_v_samp_factor = 1; 280 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 281 ci++, compptr++) { 282 if (compptr->h_samp_factor<=0 || compptr->h_samp_factor>MAX_SAMP_FACTOR || 283 compptr->v_samp_factor<=0 || compptr->v_samp_factor>MAX_SAMP_FACTOR) 284 ERREXIT(cinfo, JERR_BAD_SAMPLING); 285 cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor, 286 compptr->h_samp_factor); 287 cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor, 288 compptr->v_samp_factor); 289 } 290 291 /* Compute dimensions of components */ 292 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 293 ci++, compptr++) { 294 /* Fill in the correct component_index value; don't rely on application */ 295 compptr->component_index = ci; 296 /* In selecting the actual DCT scaling for each component, we try to 297 * scale down the chroma components via DCT scaling rather than downsampling. 298 * This saves time if the downsampler gets to use 1:1 scaling. 299 * Note this code adapts subsampling ratios which are powers of 2. 300 */ 301 ssize = 1; 302 #ifdef DCT_SCALING_SUPPORTED 303 while (cinfo->min_DCT_h_scaled_size * ssize <= 304 (cinfo->do_fancy_downsampling ? DCTSIZE : DCTSIZE / 2) && 305 (cinfo->max_h_samp_factor % (compptr->h_samp_factor * ssize * 2)) == 0) { 306 ssize = ssize * 2; 307 } 308 #endif 309 compptr->DCT_h_scaled_size = cinfo->min_DCT_h_scaled_size * ssize; 310 ssize = 1; 311 #ifdef DCT_SCALING_SUPPORTED 312 while (cinfo->min_DCT_v_scaled_size * ssize <= 313 (cinfo->do_fancy_downsampling ? DCTSIZE : DCTSIZE / 2) && 314 (cinfo->max_v_samp_factor % (compptr->v_samp_factor * ssize * 2)) == 0) { 315 ssize = ssize * 2; 316 } 317 #endif 318 compptr->DCT_v_scaled_size = cinfo->min_DCT_v_scaled_size * ssize; 319 320 /* We don't support DCT ratios larger than 2. */ 321 if (compptr->DCT_h_scaled_size > compptr->DCT_v_scaled_size * 2) 322 compptr->DCT_h_scaled_size = compptr->DCT_v_scaled_size * 2; 323 else if (compptr->DCT_v_scaled_size > compptr->DCT_h_scaled_size * 2) 324 compptr->DCT_v_scaled_size = compptr->DCT_h_scaled_size * 2; 325 326 /* Size in DCT blocks */ 327 compptr->width_in_blocks = (JDIMENSION) 328 jdiv_round_up((long) cinfo->jpeg_width * (long) compptr->h_samp_factor, 329 (long) (cinfo->max_h_samp_factor * cinfo->block_size)); 330 compptr->height_in_blocks = (JDIMENSION) 331 jdiv_round_up((long) cinfo->jpeg_height * (long) compptr->v_samp_factor, 332 (long) (cinfo->max_v_samp_factor * cinfo->block_size)); 333 /* Size in samples */ 334 compptr->downsampled_width = (JDIMENSION) 335 jdiv_round_up((long) cinfo->jpeg_width * 336 (long) (compptr->h_samp_factor * compptr->DCT_h_scaled_size), 337 (long) (cinfo->max_h_samp_factor * cinfo->block_size)); 338 compptr->downsampled_height = (JDIMENSION) 339 jdiv_round_up((long) cinfo->jpeg_height * 340 (long) (compptr->v_samp_factor * compptr->DCT_v_scaled_size), 341 (long) (cinfo->max_v_samp_factor * cinfo->block_size)); 342 /* Mark component needed (this flag isn't actually used for compression) */ 343 compptr->component_needed = TRUE; 344 } 345 346 /* Compute number of fully interleaved MCU rows (number of times that 347 * main controller will call coefficient controller). 348 */ 349 cinfo->total_iMCU_rows = (JDIMENSION) 350 jdiv_round_up((long) cinfo->jpeg_height, 351 (long) (cinfo->max_v_samp_factor * cinfo->block_size)); 352 } 353 354 355 #ifdef C_MULTISCAN_FILES_SUPPORTED 356 357 LOCAL(void) 358 validate_script (j_compress_ptr cinfo) 359 /* Verify that the scan script in cinfo->scan_info[] is valid; also 360 * determine whether it uses progressive JPEG, and set cinfo->progressive_mode. 361 */ 362 { 363 const jpeg_scan_info * scanptr; 364 int scanno, ncomps, ci, coefi, thisi; 365 int Ss, Se, Ah, Al; 366 boolean component_sent[MAX_COMPONENTS]; 367 #ifdef C_PROGRESSIVE_SUPPORTED 368 int * last_bitpos_ptr; 369 int last_bitpos[MAX_COMPONENTS][DCTSIZE2]; 370 /* -1 until that coefficient has been seen; then last Al for it */ 371 #endif 372 373 if (cinfo->num_scans <= 0) 374 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, 0); 375 376 /* For sequential JPEG, all scans must have Ss=0, Se=DCTSIZE2-1; 377 * for progressive JPEG, no scan can have this. 378 */ 379 scanptr = cinfo->scan_info; 380 if (scanptr->Ss != 0 || scanptr->Se != DCTSIZE2-1) { 381 #ifdef C_PROGRESSIVE_SUPPORTED 382 cinfo->progressive_mode = TRUE; 383 last_bitpos_ptr = & last_bitpos[0][0]; 384 for (ci = 0; ci < cinfo->num_components; ci++) 385 for (coefi = 0; coefi < DCTSIZE2; coefi++) 386 *last_bitpos_ptr++ = -1; 387 #else 388 ERREXIT(cinfo, JERR_NOT_COMPILED); 389 #endif 390 } else { 391 cinfo->progressive_mode = FALSE; 392 for (ci = 0; ci < cinfo->num_components; ci++) 393 component_sent[ci] = FALSE; 394 } 395 396 for (scanno = 1; scanno <= cinfo->num_scans; scanptr++, scanno++) { 397 /* Validate component indexes */ 398 ncomps = scanptr->comps_in_scan; 399 if (ncomps <= 0 || ncomps > MAX_COMPS_IN_SCAN) 400 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, ncomps, MAX_COMPS_IN_SCAN); 401 for (ci = 0; ci < ncomps; ci++) { 402 thisi = scanptr->component_index[ci]; 403 if (thisi < 0 || thisi >= cinfo->num_components) 404 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno); 405 /* Components must appear in SOF order within each scan */ 406 if (ci > 0 && thisi <= scanptr->component_index[ci-1]) 407 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno); 408 } 409 /* Validate progression parameters */ 410 Ss = scanptr->Ss; 411 Se = scanptr->Se; 412 Ah = scanptr->Ah; 413 Al = scanptr->Al; 414 if (cinfo->progressive_mode) { 415 #ifdef C_PROGRESSIVE_SUPPORTED 416 /* The JPEG spec simply gives the ranges 0..13 for Ah and Al, but that 417 * seems wrong: the upper bound ought to depend on data precision. 418 * Perhaps they really meant 0..N+1 for N-bit precision. 419 * Here we allow 0..10 for 8-bit data; Al larger than 10 results in 420 * out-of-range reconstructed DC values during the first DC scan, 421 * which might cause problems for some decoders. 422 */ 423 #if BITS_IN_JSAMPLE == 8 424 #define MAX_AH_AL 10 425 #else 426 #define MAX_AH_AL 13 427 #endif 428 if (Ss < 0 || Ss >= DCTSIZE2 || Se < Ss || Se >= DCTSIZE2 || 429 Ah < 0 || Ah > MAX_AH_AL || Al < 0 || Al > MAX_AH_AL) 430 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 431 if (Ss == 0) { 432 if (Se != 0) /* DC and AC together not OK */ 433 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 434 } else { 435 if (ncomps != 1) /* AC scans must be for only one component */ 436 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 437 } 438 for (ci = 0; ci < ncomps; ci++) { 439 last_bitpos_ptr = & last_bitpos[scanptr->component_index[ci]][0]; 440 if (Ss != 0 && last_bitpos_ptr[0] < 0) /* AC without prior DC scan */ 441 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 442 for (coefi = Ss; coefi <= Se; coefi++) { 443 if (last_bitpos_ptr[coefi] < 0) { 444 /* first scan of this coefficient */ 445 if (Ah != 0) 446 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 447 } else { 448 /* not first scan */ 449 if (Ah != last_bitpos_ptr[coefi] || Al != Ah-1) 450 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 451 } 452 last_bitpos_ptr[coefi] = Al; 453 } 454 } 455 #endif 456 } else { 457 /* For sequential JPEG, all progression parameters must be these: */ 458 if (Ss != 0 || Se != DCTSIZE2-1 || Ah != 0 || Al != 0) 459 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); 460 /* Make sure components are not sent twice */ 461 for (ci = 0; ci < ncomps; ci++) { 462 thisi = scanptr->component_index[ci]; 463 if (component_sent[thisi]) 464 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno); 465 component_sent[thisi] = TRUE; 466 } 467 } 468 } 469 470 /* Now verify that everything got sent. */ 471 if (cinfo->progressive_mode) { 472 #ifdef C_PROGRESSIVE_SUPPORTED 473 /* For progressive mode, we only check that at least some DC data 474 * got sent for each component; the spec does not require that all bits 475 * of all coefficients be transmitted. Would it be wiser to enforce 476 * transmission of all coefficient bits?? 477 */ 478 for (ci = 0; ci < cinfo->num_components; ci++) { 479 if (last_bitpos[ci][0] < 0) 480 ERREXIT(cinfo, JERR_MISSING_DATA); 481 } 482 #endif 483 } else { 484 for (ci = 0; ci < cinfo->num_components; ci++) { 485 if (! component_sent[ci]) 486 ERREXIT(cinfo, JERR_MISSING_DATA); 487 } 488 } 489 } 490 491 492 LOCAL(void) 493 reduce_script (j_compress_ptr cinfo) 494 /* Adapt scan script for use with reduced block size; 495 * assume that script has been validated before. 496 */ 497 { 498 jpeg_scan_info * scanptr; 499 int idxout, idxin; 500 501 /* Circumvent const declaration for this function */ 502 scanptr = (jpeg_scan_info *) cinfo->scan_info; 503 idxout = 0; 504 505 for (idxin = 0; idxin < cinfo->num_scans; idxin++) { 506 /* After skipping, idxout becomes smaller than idxin */ 507 if (idxin != idxout) 508 /* Copy rest of data; 509 * note we stay in given chunk of allocated memory. 510 */ 511 scanptr[idxout] = scanptr[idxin]; 512 if (scanptr[idxout].Ss > cinfo->lim_Se) 513 /* Entire scan out of range - skip this entry */ 514 continue; 515 if (scanptr[idxout].Se > cinfo->lim_Se) 516 /* Limit scan to end of block */ 517 scanptr[idxout].Se = cinfo->lim_Se; 518 idxout++; 519 } 520 521 cinfo->num_scans = idxout; 522 } 523 524 #endif /* C_MULTISCAN_FILES_SUPPORTED */ 525 526 527 LOCAL(void) 528 select_scan_parameters (j_compress_ptr cinfo) 529 /* Set up the scan parameters for the current scan */ 530 { 531 int ci; 532 533 #ifdef C_MULTISCAN_FILES_SUPPORTED 534 if (cinfo->scan_info != NULL) { 535 /* Prepare for current scan --- the script is already validated */ 536 my_master_ptr master = (my_master_ptr) cinfo->master; 537 const jpeg_scan_info * scanptr = cinfo->scan_info + master->scan_number; 538 539 cinfo->comps_in_scan = scanptr->comps_in_scan; 540 for (ci = 0; ci < scanptr->comps_in_scan; ci++) { 541 cinfo->cur_comp_info[ci] = 542 &cinfo->comp_info[scanptr->component_index[ci]]; 543 } 544 if (cinfo->progressive_mode) { 545 cinfo->Ss = scanptr->Ss; 546 cinfo->Se = scanptr->Se; 547 cinfo->Ah = scanptr->Ah; 548 cinfo->Al = scanptr->Al; 549 return; 550 } 551 } 552 else 553 #endif 554 { 555 /* Prepare for single sequential-JPEG scan containing all components */ 556 if (cinfo->num_components > MAX_COMPS_IN_SCAN) 557 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components, 558 MAX_COMPS_IN_SCAN); 559 cinfo->comps_in_scan = cinfo->num_components; 560 for (ci = 0; ci < cinfo->num_components; ci++) { 561 cinfo->cur_comp_info[ci] = &cinfo->comp_info[ci]; 562 } 563 } 564 cinfo->Ss = 0; 565 cinfo->Se = cinfo->block_size * cinfo->block_size - 1; 566 cinfo->Ah = 0; 567 cinfo->Al = 0; 568 } 569 570 571 LOCAL(void) 572 per_scan_setup (j_compress_ptr cinfo) 573 /* Do computations that are needed before processing a JPEG scan */ 574 /* cinfo->comps_in_scan and cinfo->cur_comp_info[] are already set */ 575 { 576 int ci, mcublks, tmp; 577 jpeg_component_info *compptr; 578 579 if (cinfo->comps_in_scan == 1) { 580 581 /* Noninterleaved (single-component) scan */ 582 compptr = cinfo->cur_comp_info[0]; 583 584 /* Overall image size in MCUs */ 585 cinfo->MCUs_per_row = compptr->width_in_blocks; 586 cinfo->MCU_rows_in_scan = compptr->height_in_blocks; 587 588 /* For noninterleaved scan, always one block per MCU */ 589 compptr->MCU_width = 1; 590 compptr->MCU_height = 1; 591 compptr->MCU_blocks = 1; 592 compptr->MCU_sample_width = compptr->DCT_h_scaled_size; 593 compptr->last_col_width = 1; 594 /* For noninterleaved scans, it is convenient to define last_row_height 595 * as the number of block rows present in the last iMCU row. 596 */ 597 tmp = (int) (compptr->height_in_blocks % compptr->v_samp_factor); 598 if (tmp == 0) tmp = compptr->v_samp_factor; 599 compptr->last_row_height = tmp; 600 601 /* Prepare array describing MCU composition */ 602 cinfo->blocks_in_MCU = 1; 603 cinfo->MCU_membership[0] = 0; 604 605 } else { 606 607 /* Interleaved (multi-component) scan */ 608 if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN) 609 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan, 610 MAX_COMPS_IN_SCAN); 611 612 /* Overall image size in MCUs */ 613 cinfo->MCUs_per_row = (JDIMENSION) 614 jdiv_round_up((long) cinfo->jpeg_width, 615 (long) (cinfo->max_h_samp_factor * cinfo->block_size)); 616 cinfo->MCU_rows_in_scan = (JDIMENSION) 617 jdiv_round_up((long) cinfo->jpeg_height, 618 (long) (cinfo->max_v_samp_factor * cinfo->block_size)); 619 620 cinfo->blocks_in_MCU = 0; 621 622 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 623 compptr = cinfo->cur_comp_info[ci]; 624 /* Sampling factors give # of blocks of component in each MCU */ 625 compptr->MCU_width = compptr->h_samp_factor; 626 compptr->MCU_height = compptr->v_samp_factor; 627 compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height; 628 compptr->MCU_sample_width = compptr->MCU_width * compptr->DCT_h_scaled_size; 629 /* Figure number of non-dummy blocks in last MCU column & row */ 630 tmp = (int) (compptr->width_in_blocks % compptr->MCU_width); 631 if (tmp == 0) tmp = compptr->MCU_width; 632 compptr->last_col_width = tmp; 633 tmp = (int) (compptr->height_in_blocks % compptr->MCU_height); 634 if (tmp == 0) tmp = compptr->MCU_height; 635 compptr->last_row_height = tmp; 636 /* Prepare array describing MCU composition */ 637 mcublks = compptr->MCU_blocks; 638 if (cinfo->blocks_in_MCU + mcublks > C_MAX_BLOCKS_IN_MCU) 639 ERREXIT(cinfo, JERR_BAD_MCU_SIZE); 640 while (mcublks-- > 0) { 641 cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci; 642 } 643 } 644 645 } 646 647 /* Convert restart specified in rows to actual MCU count. */ 648 /* Note that count must fit in 16 bits, so we provide limiting. */ 649 if (cinfo->restart_in_rows > 0) { 650 long nominal = (long) cinfo->restart_in_rows * (long) cinfo->MCUs_per_row; 651 cinfo->restart_interval = (unsigned int) MIN(nominal, 65535L); 652 } 653 } 654 655 656 /* 657 * Per-pass setup. 658 * This is called at the beginning of each pass. We determine which modules 659 * will be active during this pass and give them appropriate start_pass calls. 660 * We also set is_last_pass to indicate whether any more passes will be 661 * required. 662 */ 663 664 METHODDEF(void) 665 prepare_for_pass (j_compress_ptr cinfo) 666 { 667 my_master_ptr master = (my_master_ptr) cinfo->master; 668 669 switch (master->pass_type) { 670 case main_pass: 671 /* Initial pass: will collect input data, and do either Huffman 672 * optimization or data output for the first scan. 673 */ 674 select_scan_parameters(cinfo); 675 per_scan_setup(cinfo); 676 if (! cinfo->raw_data_in) { 677 (*cinfo->cconvert->start_pass) (cinfo); 678 (*cinfo->downsample->start_pass) (cinfo); 679 (*cinfo->prep->start_pass) (cinfo, JBUF_PASS_THRU); 680 } 681 (*cinfo->fdct->start_pass) (cinfo); 682 (*cinfo->entropy->start_pass) (cinfo, cinfo->optimize_coding); 683 (*cinfo->coef->start_pass) (cinfo, 684 (master->total_passes > 1 ? 685 JBUF_SAVE_AND_PASS : JBUF_PASS_THRU)); 686 (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU); 687 if (cinfo->optimize_coding) { 688 /* No immediate data output; postpone writing frame/scan headers */ 689 master->pub.call_pass_startup = FALSE; 690 } else { 691 /* Will write frame/scan headers at first jpeg_write_scanlines call */ 692 master->pub.call_pass_startup = TRUE; 693 } 694 break; 695 #ifdef ENTROPY_OPT_SUPPORTED 696 case huff_opt_pass: 697 /* Do Huffman optimization for a scan after the first one. */ 698 select_scan_parameters(cinfo); 699 per_scan_setup(cinfo); 700 if (cinfo->Ss != 0 || cinfo->Ah == 0) { 701 (*cinfo->entropy->start_pass) (cinfo, TRUE); 702 (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST); 703 master->pub.call_pass_startup = FALSE; 704 break; 705 } 706 /* Special case: Huffman DC refinement scans need no Huffman table 707 * and therefore we can skip the optimization pass for them. 708 */ 709 master->pass_type = output_pass; 710 master->pass_number++; 711 /*FALLTHROUGH*/ 712 #endif 713 case output_pass: 714 /* Do a data-output pass. */ 715 /* We need not repeat per-scan setup if prior optimization pass did it. */ 716 if (! cinfo->optimize_coding) { 717 select_scan_parameters(cinfo); 718 per_scan_setup(cinfo); 719 } 720 (*cinfo->entropy->start_pass) (cinfo, FALSE); 721 (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST); 722 /* We emit frame/scan headers now */ 723 if (master->scan_number == 0) 724 (*cinfo->marker->write_frame_header) (cinfo); 725 (*cinfo->marker->write_scan_header) (cinfo); 726 master->pub.call_pass_startup = FALSE; 727 break; 728 default: 729 ERREXIT(cinfo, JERR_NOT_COMPILED); 730 } 731 732 master->pub.is_last_pass = (master->pass_number == master->total_passes-1); 733 734 /* Set up progress monitor's pass info if present */ 735 if (cinfo->progress != NULL) { 736 cinfo->progress->completed_passes = master->pass_number; 737 cinfo->progress->total_passes = master->total_passes; 738 } 739 } 740 741 742 /* 743 * Special start-of-pass hook. 744 * This is called by jpeg_write_scanlines if call_pass_startup is TRUE. 745 * In single-pass processing, we need this hook because we don't want to 746 * write frame/scan headers during jpeg_start_compress; we want to let the 747 * application write COM markers etc. between jpeg_start_compress and the 748 * jpeg_write_scanlines loop. 749 * In multi-pass processing, this routine is not used. 750 */ 751 752 METHODDEF(void) 753 pass_startup (j_compress_ptr cinfo) 754 { 755 cinfo->master->call_pass_startup = FALSE; /* reset flag so call only once */ 756 757 (*cinfo->marker->write_frame_header) (cinfo); 758 (*cinfo->marker->write_scan_header) (cinfo); 759 } 760 761 762 /* 763 * Finish up at end of pass. 764 */ 765 766 METHODDEF(void) 767 finish_pass_master (j_compress_ptr cinfo) 768 { 769 my_master_ptr master = (my_master_ptr) cinfo->master; 770 771 /* The entropy coder always needs an end-of-pass call, 772 * either to analyze statistics or to flush its output buffer. 773 */ 774 (*cinfo->entropy->finish_pass) (cinfo); 775 776 /* Update state for next pass */ 777 switch (master->pass_type) { 778 case main_pass: 779 /* next pass is either output of scan 0 (after optimization) 780 * or output of scan 1 (if no optimization). 781 */ 782 master->pass_type = output_pass; 783 if (! cinfo->optimize_coding) 784 master->scan_number++; 785 break; 786 case huff_opt_pass: 787 /* next pass is always output of current scan */ 788 master->pass_type = output_pass; 789 break; 790 case output_pass: 791 /* next pass is either optimization or output of next scan */ 792 if (cinfo->optimize_coding) 793 master->pass_type = huff_opt_pass; 794 master->scan_number++; 795 break; 796 } 797 798 master->pass_number++; 799 } 800 801 802 /* 803 * Initialize master compression control. 804 */ 805 806 GLOBAL(void) 807 jinit_c_master_control (j_compress_ptr cinfo, boolean transcode_only) 808 { 809 my_master_ptr master; 810 811 master = (my_master_ptr) 812 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 813 SIZEOF(my_comp_master)); 814 cinfo->master = (struct jpeg_comp_master *) master; 815 master->pub.prepare_for_pass = prepare_for_pass; 816 master->pub.pass_startup = pass_startup; 817 master->pub.finish_pass = finish_pass_master; 818 master->pub.is_last_pass = FALSE; 819 820 /* Validate parameters, determine derived values */ 821 initial_setup(cinfo, transcode_only); 822 823 if (cinfo->scan_info != NULL) { 824 #ifdef C_MULTISCAN_FILES_SUPPORTED 825 validate_script(cinfo); 826 if (cinfo->block_size < DCTSIZE) 827 reduce_script(cinfo); 828 #else 829 ERREXIT(cinfo, JERR_NOT_COMPILED); 830 #endif 831 } else { 832 cinfo->progressive_mode = FALSE; 833 cinfo->num_scans = 1; 834 } 835 836 if ((cinfo->progressive_mode || cinfo->block_size < DCTSIZE) && 837 !cinfo->arith_code) /* TEMPORARY HACK ??? */ 838 /* assume default tables no good for progressive or downscale mode */ 839 cinfo->optimize_coding = TRUE; 840 841 /* Initialize my private state */ 842 if (transcode_only) { 843 /* no main pass in transcoding */ 844 if (cinfo->optimize_coding) 845 master->pass_type = huff_opt_pass; 846 else 847 master->pass_type = output_pass; 848 } else { 849 /* for normal compression, first pass is always this type: */ 850 master->pass_type = main_pass; 851 } 852 master->scan_number = 0; 853 master->pass_number = 0; 854 if (cinfo->optimize_coding) 855 master->total_passes = cinfo->num_scans * 2; 856 else 857 master->total_passes = cinfo->num_scans; 858 } 859
