1 /* 2 * jdmaster.c 3 * 4 * This file was part of the Independent JPEG Group's software: 5 * Copyright (C) 1991-1997, Thomas G. Lane. 6 * Modified 2002-2009 by Guido Vollbeding. 7 * libjpeg-turbo Modifications: 8 * Copyright (C) 2009-2011, 2016, D. R. Commander. 9 * Copyright (C) 2013, Linaro Limited. 10 * Copyright (C) 2015, Google, Inc. 11 * For conditions of distribution and use, see the accompanying README.ijg 12 * file. 13 * 14 * This file contains master control logic for the JPEG decompressor. 15 * These routines are concerned with selecting the modules to be executed 16 * and with determining the number of passes and the work to be done in each 17 * pass. 18 */ 19 20 #define JPEG_INTERNALS 21 #include "jinclude.h" 22 #include "jpeglib.h" 23 #include "jpegcomp.h" 24 #include "jdmaster.h" 25 #include "jsimd.h" 26 27 28 /* 29 * Determine whether merged upsample/color conversion should be used. 30 * CRUCIAL: this must match the actual capabilities of jdmerge.c! 31 */ 32 33 LOCAL(boolean) 34 use_merged_upsample (j_decompress_ptr cinfo) 35 { 36 #ifdef UPSAMPLE_MERGING_SUPPORTED 37 /* Merging is the equivalent of plain box-filter upsampling */ 38 if (cinfo->do_fancy_upsampling || cinfo->CCIR601_sampling) 39 return FALSE; 40 /* jdmerge.c only supports YCC=>RGB and YCC=>RGB565 color conversion */ 41 if (cinfo->jpeg_color_space != JCS_YCbCr || cinfo->num_components != 3 || 42 (cinfo->out_color_space != JCS_RGB && 43 cinfo->out_color_space != JCS_RGB565 && 44 cinfo->out_color_space != JCS_EXT_RGB && 45 cinfo->out_color_space != JCS_EXT_RGBX && 46 cinfo->out_color_space != JCS_EXT_BGR && 47 cinfo->out_color_space != JCS_EXT_BGRX && 48 cinfo->out_color_space != JCS_EXT_XBGR && 49 cinfo->out_color_space != JCS_EXT_XRGB && 50 cinfo->out_color_space != JCS_EXT_RGBA && 51 cinfo->out_color_space != JCS_EXT_BGRA && 52 cinfo->out_color_space != JCS_EXT_ABGR && 53 cinfo->out_color_space != JCS_EXT_ARGB)) 54 return FALSE; 55 if ((cinfo->out_color_space == JCS_RGB565 && 56 cinfo->out_color_components != 3) || 57 (cinfo->out_color_space != JCS_RGB565 && 58 cinfo->out_color_components != rgb_pixelsize[cinfo->out_color_space])) 59 return FALSE; 60 /* and it only handles 2h1v or 2h2v sampling ratios */ 61 if (cinfo->comp_info[0].h_samp_factor != 2 || 62 cinfo->comp_info[1].h_samp_factor != 1 || 63 cinfo->comp_info[2].h_samp_factor != 1 || 64 cinfo->comp_info[0].v_samp_factor > 2 || 65 cinfo->comp_info[1].v_samp_factor != 1 || 66 cinfo->comp_info[2].v_samp_factor != 1) 67 return FALSE; 68 /* furthermore, it doesn't work if we've scaled the IDCTs differently */ 69 if (cinfo->comp_info[0]._DCT_scaled_size != cinfo->_min_DCT_scaled_size || 70 cinfo->comp_info[1]._DCT_scaled_size != cinfo->_min_DCT_scaled_size || 71 cinfo->comp_info[2]._DCT_scaled_size != cinfo->_min_DCT_scaled_size) 72 return FALSE; 73 #ifdef WITH_SIMD 74 /* If YCbCr-to-RGB color conversion is SIMD-accelerated but merged upsampling 75 isn't, then disabling merged upsampling is likely to be faster when 76 decompressing YCbCr JPEG images. */ 77 if (!jsimd_can_h2v2_merged_upsample() && !jsimd_can_h2v1_merged_upsample() && 78 jsimd_can_ycc_rgb() && cinfo->jpeg_color_space == JCS_YCbCr && 79 (cinfo->out_color_space == JCS_RGB || 80 (cinfo->out_color_space >= JCS_EXT_RGB && 81 cinfo->out_color_space <= JCS_EXT_ARGB))) 82 return FALSE; 83 #endif 84 /* ??? also need to test for upsample-time rescaling, when & if supported */ 85 return TRUE; /* by golly, it'll work... */ 86 #else 87 return FALSE; 88 #endif 89 } 90 91 92 /* 93 * Compute output image dimensions and related values. 94 * NOTE: this is exported for possible use by application. 95 * Hence it mustn't do anything that can't be done twice. 96 */ 97 98 #if JPEG_LIB_VERSION >= 80 99 GLOBAL(void) 100 #else 101 LOCAL(void) 102 #endif 103 jpeg_core_output_dimensions (j_decompress_ptr cinfo) 104 /* Do computations that are needed before master selection phase. 105 * This function is used for transcoding and full decompression. 106 */ 107 { 108 #ifdef IDCT_SCALING_SUPPORTED 109 int ci; 110 jpeg_component_info *compptr; 111 112 /* Compute actual output image dimensions and DCT scaling choices. */ 113 if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom) { 114 /* Provide 1/block_size scaling */ 115 cinfo->output_width = (JDIMENSION) 116 jdiv_round_up((long) cinfo->image_width, (long) DCTSIZE); 117 cinfo->output_height = (JDIMENSION) 118 jdiv_round_up((long) cinfo->image_height, (long) DCTSIZE); 119 cinfo->_min_DCT_h_scaled_size = 1; 120 cinfo->_min_DCT_v_scaled_size = 1; 121 } else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 2) { 122 /* Provide 2/block_size scaling */ 123 cinfo->output_width = (JDIMENSION) 124 jdiv_round_up((long) cinfo->image_width * 2L, (long) DCTSIZE); 125 cinfo->output_height = (JDIMENSION) 126 jdiv_round_up((long) cinfo->image_height * 2L, (long) DCTSIZE); 127 cinfo->_min_DCT_h_scaled_size = 2; 128 cinfo->_min_DCT_v_scaled_size = 2; 129 } else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 3) { 130 /* Provide 3/block_size scaling */ 131 cinfo->output_width = (JDIMENSION) 132 jdiv_round_up((long) cinfo->image_width * 3L, (long) DCTSIZE); 133 cinfo->output_height = (JDIMENSION) 134 jdiv_round_up((long) cinfo->image_height * 3L, (long) DCTSIZE); 135 cinfo->_min_DCT_h_scaled_size = 3; 136 cinfo->_min_DCT_v_scaled_size = 3; 137 } else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 4) { 138 /* Provide 4/block_size scaling */ 139 cinfo->output_width = (JDIMENSION) 140 jdiv_round_up((long) cinfo->image_width * 4L, (long) DCTSIZE); 141 cinfo->output_height = (JDIMENSION) 142 jdiv_round_up((long) cinfo->image_height * 4L, (long) DCTSIZE); 143 cinfo->_min_DCT_h_scaled_size = 4; 144 cinfo->_min_DCT_v_scaled_size = 4; 145 } else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 5) { 146 /* Provide 5/block_size scaling */ 147 cinfo->output_width = (JDIMENSION) 148 jdiv_round_up((long) cinfo->image_width * 5L, (long) DCTSIZE); 149 cinfo->output_height = (JDIMENSION) 150 jdiv_round_up((long) cinfo->image_height * 5L, (long) DCTSIZE); 151 cinfo->_min_DCT_h_scaled_size = 5; 152 cinfo->_min_DCT_v_scaled_size = 5; 153 } else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 6) { 154 /* Provide 6/block_size scaling */ 155 cinfo->output_width = (JDIMENSION) 156 jdiv_round_up((long) cinfo->image_width * 6L, (long) DCTSIZE); 157 cinfo->output_height = (JDIMENSION) 158 jdiv_round_up((long) cinfo->image_height * 6L, (long) DCTSIZE); 159 cinfo->_min_DCT_h_scaled_size = 6; 160 cinfo->_min_DCT_v_scaled_size = 6; 161 } else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 7) { 162 /* Provide 7/block_size scaling */ 163 cinfo->output_width = (JDIMENSION) 164 jdiv_round_up((long) cinfo->image_width * 7L, (long) DCTSIZE); 165 cinfo->output_height = (JDIMENSION) 166 jdiv_round_up((long) cinfo->image_height * 7L, (long) DCTSIZE); 167 cinfo->_min_DCT_h_scaled_size = 7; 168 cinfo->_min_DCT_v_scaled_size = 7; 169 } else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 8) { 170 /* Provide 8/block_size scaling */ 171 cinfo->output_width = (JDIMENSION) 172 jdiv_round_up((long) cinfo->image_width * 8L, (long) DCTSIZE); 173 cinfo->output_height = (JDIMENSION) 174 jdiv_round_up((long) cinfo->image_height * 8L, (long) DCTSIZE); 175 cinfo->_min_DCT_h_scaled_size = 8; 176 cinfo->_min_DCT_v_scaled_size = 8; 177 } else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 9) { 178 /* Provide 9/block_size scaling */ 179 cinfo->output_width = (JDIMENSION) 180 jdiv_round_up((long) cinfo->image_width * 9L, (long) DCTSIZE); 181 cinfo->output_height = (JDIMENSION) 182 jdiv_round_up((long) cinfo->image_height * 9L, (long) DCTSIZE); 183 cinfo->_min_DCT_h_scaled_size = 9; 184 cinfo->_min_DCT_v_scaled_size = 9; 185 } else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 10) { 186 /* Provide 10/block_size scaling */ 187 cinfo->output_width = (JDIMENSION) 188 jdiv_round_up((long) cinfo->image_width * 10L, (long) DCTSIZE); 189 cinfo->output_height = (JDIMENSION) 190 jdiv_round_up((long) cinfo->image_height * 10L, (long) DCTSIZE); 191 cinfo->_min_DCT_h_scaled_size = 10; 192 cinfo->_min_DCT_v_scaled_size = 10; 193 } else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 11) { 194 /* Provide 11/block_size scaling */ 195 cinfo->output_width = (JDIMENSION) 196 jdiv_round_up((long) cinfo->image_width * 11L, (long) DCTSIZE); 197 cinfo->output_height = (JDIMENSION) 198 jdiv_round_up((long) cinfo->image_height * 11L, (long) DCTSIZE); 199 cinfo->_min_DCT_h_scaled_size = 11; 200 cinfo->_min_DCT_v_scaled_size = 11; 201 } else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 12) { 202 /* Provide 12/block_size scaling */ 203 cinfo->output_width = (JDIMENSION) 204 jdiv_round_up((long) cinfo->image_width * 12L, (long) DCTSIZE); 205 cinfo->output_height = (JDIMENSION) 206 jdiv_round_up((long) cinfo->image_height * 12L, (long) DCTSIZE); 207 cinfo->_min_DCT_h_scaled_size = 12; 208 cinfo->_min_DCT_v_scaled_size = 12; 209 } else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 13) { 210 /* Provide 13/block_size scaling */ 211 cinfo->output_width = (JDIMENSION) 212 jdiv_round_up((long) cinfo->image_width * 13L, (long) DCTSIZE); 213 cinfo->output_height = (JDIMENSION) 214 jdiv_round_up((long) cinfo->image_height * 13L, (long) DCTSIZE); 215 cinfo->_min_DCT_h_scaled_size = 13; 216 cinfo->_min_DCT_v_scaled_size = 13; 217 } else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 14) { 218 /* Provide 14/block_size scaling */ 219 cinfo->output_width = (JDIMENSION) 220 jdiv_round_up((long) cinfo->image_width * 14L, (long) DCTSIZE); 221 cinfo->output_height = (JDIMENSION) 222 jdiv_round_up((long) cinfo->image_height * 14L, (long) DCTSIZE); 223 cinfo->_min_DCT_h_scaled_size = 14; 224 cinfo->_min_DCT_v_scaled_size = 14; 225 } else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 15) { 226 /* Provide 15/block_size scaling */ 227 cinfo->output_width = (JDIMENSION) 228 jdiv_round_up((long) cinfo->image_width * 15L, (long) DCTSIZE); 229 cinfo->output_height = (JDIMENSION) 230 jdiv_round_up((long) cinfo->image_height * 15L, (long) DCTSIZE); 231 cinfo->_min_DCT_h_scaled_size = 15; 232 cinfo->_min_DCT_v_scaled_size = 15; 233 } else { 234 /* Provide 16/block_size scaling */ 235 cinfo->output_width = (JDIMENSION) 236 jdiv_round_up((long) cinfo->image_width * 16L, (long) DCTSIZE); 237 cinfo->output_height = (JDIMENSION) 238 jdiv_round_up((long) cinfo->image_height * 16L, (long) DCTSIZE); 239 cinfo->_min_DCT_h_scaled_size = 16; 240 cinfo->_min_DCT_v_scaled_size = 16; 241 } 242 243 /* Recompute dimensions of components */ 244 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 245 ci++, compptr++) { 246 compptr->_DCT_h_scaled_size = cinfo->_min_DCT_h_scaled_size; 247 compptr->_DCT_v_scaled_size = cinfo->_min_DCT_v_scaled_size; 248 } 249 250 #else /* !IDCT_SCALING_SUPPORTED */ 251 252 /* Hardwire it to "no scaling" */ 253 cinfo->output_width = cinfo->image_width; 254 cinfo->output_height = cinfo->image_height; 255 /* jdinput.c has already initialized DCT_scaled_size, 256 * and has computed unscaled downsampled_width and downsampled_height. 257 */ 258 259 #endif /* IDCT_SCALING_SUPPORTED */ 260 } 261 262 263 /* 264 * Compute output image dimensions and related values. 265 * NOTE: this is exported for possible use by application. 266 * Hence it mustn't do anything that can't be done twice. 267 * Also note that it may be called before the master module is initialized! 268 */ 269 270 GLOBAL(void) 271 jpeg_calc_output_dimensions (j_decompress_ptr cinfo) 272 /* Do computations that are needed before master selection phase */ 273 { 274 #ifdef IDCT_SCALING_SUPPORTED 275 int ci; 276 jpeg_component_info *compptr; 277 #endif 278 279 /* Prevent application from calling me at wrong times */ 280 if (cinfo->global_state != DSTATE_READY) 281 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); 282 283 /* Compute core output image dimensions and DCT scaling choices. */ 284 jpeg_core_output_dimensions(cinfo); 285 286 #ifdef IDCT_SCALING_SUPPORTED 287 288 /* In selecting the actual DCT scaling for each component, we try to 289 * scale up the chroma components via IDCT scaling rather than upsampling. 290 * This saves time if the upsampler gets to use 1:1 scaling. 291 * Note this code adapts subsampling ratios which are powers of 2. 292 */ 293 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 294 ci++, compptr++) { 295 int ssize = cinfo->_min_DCT_scaled_size; 296 while (ssize < DCTSIZE && 297 ((cinfo->max_h_samp_factor * cinfo->_min_DCT_scaled_size) % 298 (compptr->h_samp_factor * ssize * 2) == 0) && 299 ((cinfo->max_v_samp_factor * cinfo->_min_DCT_scaled_size) % 300 (compptr->v_samp_factor * ssize * 2) == 0)) { 301 ssize = ssize * 2; 302 } 303 #if JPEG_LIB_VERSION >= 70 304 compptr->DCT_h_scaled_size = compptr->DCT_v_scaled_size = ssize; 305 #else 306 compptr->DCT_scaled_size = ssize; 307 #endif 308 } 309 310 /* Recompute downsampled dimensions of components; 311 * application needs to know these if using raw downsampled data. 312 */ 313 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 314 ci++, compptr++) { 315 /* Size in samples, after IDCT scaling */ 316 compptr->downsampled_width = (JDIMENSION) 317 jdiv_round_up((long) cinfo->image_width * 318 (long) (compptr->h_samp_factor * compptr->_DCT_scaled_size), 319 (long) (cinfo->max_h_samp_factor * DCTSIZE)); 320 compptr->downsampled_height = (JDIMENSION) 321 jdiv_round_up((long) cinfo->image_height * 322 (long) (compptr->v_samp_factor * compptr->_DCT_scaled_size), 323 (long) (cinfo->max_v_samp_factor * DCTSIZE)); 324 } 325 326 #else /* !IDCT_SCALING_SUPPORTED */ 327 328 /* Hardwire it to "no scaling" */ 329 cinfo->output_width = cinfo->image_width; 330 cinfo->output_height = cinfo->image_height; 331 /* jdinput.c has already initialized DCT_scaled_size to DCTSIZE, 332 * and has computed unscaled downsampled_width and downsampled_height. 333 */ 334 335 #endif /* IDCT_SCALING_SUPPORTED */ 336 337 /* Report number of components in selected colorspace. */ 338 /* Probably this should be in the color conversion module... */ 339 switch (cinfo->out_color_space) { 340 case JCS_GRAYSCALE: 341 cinfo->out_color_components = 1; 342 break; 343 case JCS_RGB: 344 case JCS_EXT_RGB: 345 case JCS_EXT_RGBX: 346 case JCS_EXT_BGR: 347 case JCS_EXT_BGRX: 348 case JCS_EXT_XBGR: 349 case JCS_EXT_XRGB: 350 case JCS_EXT_RGBA: 351 case JCS_EXT_BGRA: 352 case JCS_EXT_ABGR: 353 case JCS_EXT_ARGB: 354 cinfo->out_color_components = rgb_pixelsize[cinfo->out_color_space]; 355 break; 356 case JCS_YCbCr: 357 case JCS_RGB565: 358 cinfo->out_color_components = 3; 359 break; 360 case JCS_CMYK: 361 case JCS_YCCK: 362 cinfo->out_color_components = 4; 363 break; 364 default: /* else must be same colorspace as in file */ 365 cinfo->out_color_components = cinfo->num_components; 366 break; 367 } 368 cinfo->output_components = (cinfo->quantize_colors ? 1 : 369 cinfo->out_color_components); 370 371 /* See if upsampler will want to emit more than one row at a time */ 372 if (use_merged_upsample(cinfo)) 373 cinfo->rec_outbuf_height = cinfo->max_v_samp_factor; 374 else 375 cinfo->rec_outbuf_height = 1; 376 } 377 378 379 /* 380 * Several decompression processes need to range-limit values to the range 381 * 0..MAXJSAMPLE; the input value may fall somewhat outside this range 382 * due to noise introduced by quantization, roundoff error, etc. These 383 * processes are inner loops and need to be as fast as possible. On most 384 * machines, particularly CPUs with pipelines or instruction prefetch, 385 * a (subscript-check-less) C table lookup 386 * x = sample_range_limit[x]; 387 * is faster than explicit tests 388 * if (x < 0) x = 0; 389 * else if (x > MAXJSAMPLE) x = MAXJSAMPLE; 390 * These processes all use a common table prepared by the routine below. 391 * 392 * For most steps we can mathematically guarantee that the initial value 393 * of x is within MAXJSAMPLE+1 of the legal range, so a table running from 394 * -(MAXJSAMPLE+1) to 2*MAXJSAMPLE+1 is sufficient. But for the initial 395 * limiting step (just after the IDCT), a wildly out-of-range value is 396 * possible if the input data is corrupt. To avoid any chance of indexing 397 * off the end of memory and getting a bad-pointer trap, we perform the 398 * post-IDCT limiting thus: 399 * x = range_limit[x & MASK]; 400 * where MASK is 2 bits wider than legal sample data, ie 10 bits for 8-bit 401 * samples. Under normal circumstances this is more than enough range and 402 * a correct output will be generated; with bogus input data the mask will 403 * cause wraparound, and we will safely generate a bogus-but-in-range output. 404 * For the post-IDCT step, we want to convert the data from signed to unsigned 405 * representation by adding CENTERJSAMPLE at the same time that we limit it. 406 * So the post-IDCT limiting table ends up looking like this: 407 * CENTERJSAMPLE,CENTERJSAMPLE+1,...,MAXJSAMPLE, 408 * MAXJSAMPLE (repeat 2*(MAXJSAMPLE+1)-CENTERJSAMPLE times), 409 * 0 (repeat 2*(MAXJSAMPLE+1)-CENTERJSAMPLE times), 410 * 0,1,...,CENTERJSAMPLE-1 411 * Negative inputs select values from the upper half of the table after 412 * masking. 413 * 414 * We can save some space by overlapping the start of the post-IDCT table 415 * with the simpler range limiting table. The post-IDCT table begins at 416 * sample_range_limit + CENTERJSAMPLE. 417 */ 418 419 LOCAL(void) 420 prepare_range_limit_table (j_decompress_ptr cinfo) 421 /* Allocate and fill in the sample_range_limit table */ 422 { 423 JSAMPLE *table; 424 int i; 425 426 table = (JSAMPLE *) 427 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 428 (5 * (MAXJSAMPLE+1) + CENTERJSAMPLE) * sizeof(JSAMPLE)); 429 table += (MAXJSAMPLE+1); /* allow negative subscripts of simple table */ 430 cinfo->sample_range_limit = table; 431 /* First segment of "simple" table: limit[x] = 0 for x < 0 */ 432 MEMZERO(table - (MAXJSAMPLE+1), (MAXJSAMPLE+1) * sizeof(JSAMPLE)); 433 /* Main part of "simple" table: limit[x] = x */ 434 for (i = 0; i <= MAXJSAMPLE; i++) 435 table[i] = (JSAMPLE) i; 436 table += CENTERJSAMPLE; /* Point to where post-IDCT table starts */ 437 /* End of simple table, rest of first half of post-IDCT table */ 438 for (i = CENTERJSAMPLE; i < 2*(MAXJSAMPLE+1); i++) 439 table[i] = MAXJSAMPLE; 440 /* Second half of post-IDCT table */ 441 MEMZERO(table + (2 * (MAXJSAMPLE+1)), 442 (2 * (MAXJSAMPLE+1) - CENTERJSAMPLE) * sizeof(JSAMPLE)); 443 MEMCOPY(table + (4 * (MAXJSAMPLE+1) - CENTERJSAMPLE), 444 cinfo->sample_range_limit, CENTERJSAMPLE * sizeof(JSAMPLE)); 445 } 446 447 448 /* 449 * Master selection of decompression modules. 450 * This is done once at jpeg_start_decompress time. We determine 451 * which modules will be used and give them appropriate initialization calls. 452 * We also initialize the decompressor input side to begin consuming data. 453 * 454 * Since jpeg_read_header has finished, we know what is in the SOF 455 * and (first) SOS markers. We also have all the application parameter 456 * settings. 457 */ 458 459 LOCAL(void) 460 master_selection (j_decompress_ptr cinfo) 461 { 462 my_master_ptr master = (my_master_ptr) cinfo->master; 463 boolean use_c_buffer; 464 long samplesperrow; 465 JDIMENSION jd_samplesperrow; 466 467 /* Initialize dimensions and other stuff */ 468 jpeg_calc_output_dimensions(cinfo); 469 prepare_range_limit_table(cinfo); 470 471 /* Width of an output scanline must be representable as JDIMENSION. */ 472 samplesperrow = (long) cinfo->output_width * (long) cinfo->out_color_components; 473 jd_samplesperrow = (JDIMENSION) samplesperrow; 474 if ((long) jd_samplesperrow != samplesperrow) 475 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); 476 477 /* Initialize my private state */ 478 master->pass_number = 0; 479 master->using_merged_upsample = use_merged_upsample(cinfo); 480 481 /* Color quantizer selection */ 482 master->quantizer_1pass = NULL; 483 master->quantizer_2pass = NULL; 484 /* No mode changes if not using buffered-image mode. */ 485 if (! cinfo->quantize_colors || ! cinfo->buffered_image) { 486 cinfo->enable_1pass_quant = FALSE; 487 cinfo->enable_external_quant = FALSE; 488 cinfo->enable_2pass_quant = FALSE; 489 } 490 if (cinfo->quantize_colors) { 491 if (cinfo->raw_data_out) 492 ERREXIT(cinfo, JERR_NOTIMPL); 493 /* 2-pass quantizer only works in 3-component color space. */ 494 if (cinfo->out_color_components != 3) { 495 cinfo->enable_1pass_quant = TRUE; 496 cinfo->enable_external_quant = FALSE; 497 cinfo->enable_2pass_quant = FALSE; 498 cinfo->colormap = NULL; 499 } else if (cinfo->colormap != NULL) { 500 cinfo->enable_external_quant = TRUE; 501 } else if (cinfo->two_pass_quantize) { 502 cinfo->enable_2pass_quant = TRUE; 503 } else { 504 cinfo->enable_1pass_quant = TRUE; 505 } 506 507 if (cinfo->enable_1pass_quant) { 508 #ifdef QUANT_1PASS_SUPPORTED 509 jinit_1pass_quantizer(cinfo); 510 master->quantizer_1pass = cinfo->cquantize; 511 #else 512 ERREXIT(cinfo, JERR_NOT_COMPILED); 513 #endif 514 } 515 516 /* We use the 2-pass code to map to external colormaps. */ 517 if (cinfo->enable_2pass_quant || cinfo->enable_external_quant) { 518 #ifdef QUANT_2PASS_SUPPORTED 519 jinit_2pass_quantizer(cinfo); 520 master->quantizer_2pass = cinfo->cquantize; 521 #else 522 ERREXIT(cinfo, JERR_NOT_COMPILED); 523 #endif 524 } 525 /* If both quantizers are initialized, the 2-pass one is left active; 526 * this is necessary for starting with quantization to an external map. 527 */ 528 } 529 530 /* Post-processing: in particular, color conversion first */ 531 if (! cinfo->raw_data_out) { 532 if (master->using_merged_upsample) { 533 #ifdef UPSAMPLE_MERGING_SUPPORTED 534 jinit_merged_upsampler(cinfo); /* does color conversion too */ 535 #else 536 ERREXIT(cinfo, JERR_NOT_COMPILED); 537 #endif 538 } else { 539 jinit_color_deconverter(cinfo); 540 jinit_upsampler(cinfo); 541 } 542 jinit_d_post_controller(cinfo, cinfo->enable_2pass_quant); 543 } 544 /* Inverse DCT */ 545 jinit_inverse_dct(cinfo); 546 /* Entropy decoding: either Huffman or arithmetic coding. */ 547 if (cinfo->arith_code) { 548 #ifdef D_ARITH_CODING_SUPPORTED 549 jinit_arith_decoder(cinfo); 550 #else 551 ERREXIT(cinfo, JERR_ARITH_NOTIMPL); 552 #endif 553 } else { 554 if (cinfo->progressive_mode) { 555 #ifdef D_PROGRESSIVE_SUPPORTED 556 jinit_phuff_decoder(cinfo); 557 #else 558 ERREXIT(cinfo, JERR_NOT_COMPILED); 559 #endif 560 } else 561 jinit_huff_decoder(cinfo); 562 } 563 564 /* Initialize principal buffer controllers. */ 565 use_c_buffer = cinfo->inputctl->has_multiple_scans || cinfo->buffered_image; 566 jinit_d_coef_controller(cinfo, use_c_buffer); 567 568 if (! cinfo->raw_data_out) 569 jinit_d_main_controller(cinfo, FALSE /* never need full buffer here */); 570 571 /* We can now tell the memory manager to allocate virtual arrays. */ 572 (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo); 573 574 /* Initialize input side of decompressor to consume first scan. */ 575 (*cinfo->inputctl->start_input_pass) (cinfo); 576 577 /* Set the first and last iMCU columns to decompress from single-scan images. 578 * By default, decompress all of the iMCU columns. 579 */ 580 cinfo->master->first_iMCU_col = 0; 581 cinfo->master->last_iMCU_col = cinfo->MCUs_per_row - 1; 582 583 #ifdef D_MULTISCAN_FILES_SUPPORTED 584 /* If jpeg_start_decompress will read the whole file, initialize 585 * progress monitoring appropriately. The input step is counted 586 * as one pass. 587 */ 588 if (cinfo->progress != NULL && ! cinfo->buffered_image && 589 cinfo->inputctl->has_multiple_scans) { 590 int nscans; 591 /* Estimate number of scans to set pass_limit. */ 592 if (cinfo->progressive_mode) { 593 /* Arbitrarily estimate 2 interleaved DC scans + 3 AC scans/component. */ 594 nscans = 2 + 3 * cinfo->num_components; 595 } else { 596 /* For a nonprogressive multiscan file, estimate 1 scan per component. */ 597 nscans = cinfo->num_components; 598 } 599 cinfo->progress->pass_counter = 0L; 600 cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows * nscans; 601 cinfo->progress->completed_passes = 0; 602 cinfo->progress->total_passes = (cinfo->enable_2pass_quant ? 3 : 2); 603 /* Count the input pass as done */ 604 master->pass_number++; 605 } 606 #endif /* D_MULTISCAN_FILES_SUPPORTED */ 607 } 608 609 610 /* 611 * Per-pass setup. 612 * This is called at the beginning of each output pass. We determine which 613 * modules will be active during this pass and give them appropriate 614 * start_pass calls. We also set is_dummy_pass to indicate whether this 615 * is a "real" output pass or a dummy pass for color quantization. 616 * (In the latter case, jdapistd.c will crank the pass to completion.) 617 */ 618 619 METHODDEF(void) 620 prepare_for_output_pass (j_decompress_ptr cinfo) 621 { 622 my_master_ptr master = (my_master_ptr) cinfo->master; 623 624 if (master->pub.is_dummy_pass) { 625 #ifdef QUANT_2PASS_SUPPORTED 626 /* Final pass of 2-pass quantization */ 627 master->pub.is_dummy_pass = FALSE; 628 (*cinfo->cquantize->start_pass) (cinfo, FALSE); 629 (*cinfo->post->start_pass) (cinfo, JBUF_CRANK_DEST); 630 (*cinfo->main->start_pass) (cinfo, JBUF_CRANK_DEST); 631 #else 632 ERREXIT(cinfo, JERR_NOT_COMPILED); 633 #endif /* QUANT_2PASS_SUPPORTED */ 634 } else { 635 if (cinfo->quantize_colors && cinfo->colormap == NULL) { 636 /* Select new quantization method */ 637 if (cinfo->two_pass_quantize && cinfo->enable_2pass_quant) { 638 cinfo->cquantize = master->quantizer_2pass; 639 master->pub.is_dummy_pass = TRUE; 640 } else if (cinfo->enable_1pass_quant) { 641 cinfo->cquantize = master->quantizer_1pass; 642 } else { 643 ERREXIT(cinfo, JERR_MODE_CHANGE); 644 } 645 } 646 (*cinfo->idct->start_pass) (cinfo); 647 (*cinfo->coef->start_output_pass) (cinfo); 648 if (! cinfo->raw_data_out) { 649 if (! master->using_merged_upsample) 650 (*cinfo->cconvert->start_pass) (cinfo); 651 (*cinfo->upsample->start_pass) (cinfo); 652 if (cinfo->quantize_colors) 653 (*cinfo->cquantize->start_pass) (cinfo, master->pub.is_dummy_pass); 654 (*cinfo->post->start_pass) (cinfo, 655 (master->pub.is_dummy_pass ? JBUF_SAVE_AND_PASS : JBUF_PASS_THRU)); 656 (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU); 657 } 658 } 659 660 /* Set up progress monitor's pass info if present */ 661 if (cinfo->progress != NULL) { 662 cinfo->progress->completed_passes = master->pass_number; 663 cinfo->progress->total_passes = master->pass_number + 664 (master->pub.is_dummy_pass ? 2 : 1); 665 /* In buffered-image mode, we assume one more output pass if EOI not 666 * yet reached, but no more passes if EOI has been reached. 667 */ 668 if (cinfo->buffered_image && ! cinfo->inputctl->eoi_reached) { 669 cinfo->progress->total_passes += (cinfo->enable_2pass_quant ? 2 : 1); 670 } 671 } 672 } 673 674 675 /* 676 * Finish up at end of an output pass. 677 */ 678 679 METHODDEF(void) 680 finish_output_pass (j_decompress_ptr cinfo) 681 { 682 my_master_ptr master = (my_master_ptr) cinfo->master; 683 684 if (cinfo->quantize_colors) 685 (*cinfo->cquantize->finish_pass) (cinfo); 686 master->pass_number++; 687 } 688 689 690 #ifdef D_MULTISCAN_FILES_SUPPORTED 691 692 /* 693 * Switch to a new external colormap between output passes. 694 */ 695 696 GLOBAL(void) 697 jpeg_new_colormap (j_decompress_ptr cinfo) 698 { 699 my_master_ptr master = (my_master_ptr) cinfo->master; 700 701 /* Prevent application from calling me at wrong times */ 702 if (cinfo->global_state != DSTATE_BUFIMAGE) 703 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); 704 705 if (cinfo->quantize_colors && cinfo->enable_external_quant && 706 cinfo->colormap != NULL) { 707 /* Select 2-pass quantizer for external colormap use */ 708 cinfo->cquantize = master->quantizer_2pass; 709 /* Notify quantizer of colormap change */ 710 (*cinfo->cquantize->new_color_map) (cinfo); 711 master->pub.is_dummy_pass = FALSE; /* just in case */ 712 } else 713 ERREXIT(cinfo, JERR_MODE_CHANGE); 714 } 715 716 #endif /* D_MULTISCAN_FILES_SUPPORTED */ 717 718 719 /* 720 * Initialize master decompression control and select active modules. 721 * This is performed at the start of jpeg_start_decompress. 722 */ 723 724 GLOBAL(void) 725 jinit_master_decompress (j_decompress_ptr cinfo) 726 { 727 my_master_ptr master = (my_master_ptr) cinfo->master; 728 729 master->pub.prepare_for_output_pass = prepare_for_output_pass; 730 master->pub.finish_output_pass = finish_output_pass; 731 732 master->pub.is_dummy_pass = FALSE; 733 master->pub.jinit_upsampler_no_alloc = FALSE; 734 735 master_selection(cinfo); 736 } 737
