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| 1 /* | |
| 2 * jdcoefct.c | |
| 3 * | |
| 4 * Copyright (C) 1994-1997, 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 the coefficient buffer controller for decompression. | |
| 9 * This controller is the top level of the JPEG decompressor proper. | |
| 10 * The coefficient buffer lies between entropy decoding and inverse-DCT steps. | |
| 11 * | |
| 12 * In buffered-image mode, this controller is the interface between | |
| 13 * input-oriented processing and output-oriented processing. | |
| 14 * Also, the input side (only) is used when reading a file for transcoding. | |
| 15 */ | |
| 16 | |
| 17 #define JPEG_INTERNALS | |
| 18 #include "jinclude.h" | |
| 19 #include "jpeglib.h" | |
| 20 | |
| 21 /* Block smoothing is only applicable for progressive JPEG, so: */ | |
| 22 #ifndef D_PROGRESSIVE_SUPPORTED | |
| 23 #undef BLOCK_SMOOTHING_SUPPORTED | |
| 24 #endif | |
| 25 | |
| 26 /* Private buffer controller object */ | |
| 27 | |
| 28 typedef struct { | |
| 29 struct jpeg_d_coef_controller pub; /* public fields */ | |
| 30 | |
| 31 /* These variables keep track of the current location of the input side. */ | |
| 32 /* cinfo->input_iMCU_row is also used for this. */ | |
| 33 JDIMENSION MCU_ctr; /* counts MCUs processed in current row */ | |
| 34 int MCU_vert_offset; /* counts MCU rows within iMCU row */ | |
| 35 int MCU_rows_per_iMCU_row; /* number of such rows needed */ | |
| 36 | |
| 37 /* The output side's location is represented by cinfo->output_iMCU_row. */ | |
| 38 | |
| 39 /* In single-pass modes, it's sufficient to buffer just one MCU. | |
| 40 * We allocate a workspace of D_MAX_BLOCKS_IN_MCU coefficient blocks, | |
| 41 * and let the entropy decoder write into that workspace each time. | |
| 42 * (On 80x86, the workspace is FAR even though it's not really very big; | |
| 43 * this is to keep the module interfaces unchanged when a large coefficient | |
| 44 * buffer is necessary.) | |
| 45 * In multi-pass modes, this array points to the current MCU's blocks | |
| 46 * within the virtual arrays; it is used only by the input side. | |
| 47 */ | |
| 48 JBLOCKROW MCU_buffer[D_MAX_BLOCKS_IN_MCU]; | |
| 49 | |
| 50 #ifdef D_MULTISCAN_FILES_SUPPORTED | |
| 51 /* In multi-pass modes, we need a virtual block array for each component. */ | |
| 52 jvirt_barray_ptr whole_image[MAX_COMPONENTS]; | |
| 53 #endif | |
| 54 | |
| 55 #ifdef BLOCK_SMOOTHING_SUPPORTED | |
| 56 /* When doing block smoothing, we latch coefficient Al values here */ | |
| 57 int * coef_bits_latch; | |
| 58 #define SAVED_COEFS 6 /* we save coef_bits[0..5] */ | |
| 59 #endif | |
| 60 } my_coef_controller; | |
| 61 | |
| 62 typedef my_coef_controller * my_coef_ptr; | |
| 63 | |
| 64 /* Forward declarations */ | |
| 65 METHODDEF(int) decompress_onepass | |
| 66 JPP((j_decompress_ptr cinfo, JSAMPIMAGE output_buf)); | |
| 67 #ifdef D_MULTISCAN_FILES_SUPPORTED | |
| 68 METHODDEF(int) decompress_data | |
| 69 JPP((j_decompress_ptr cinfo, JSAMPIMAGE output_buf)); | |
| 70 #endif | |
| 71 #ifdef BLOCK_SMOOTHING_SUPPORTED | |
| 72 LOCAL(boolean) smoothing_ok JPP((j_decompress_ptr cinfo)); | |
| 73 METHODDEF(int) decompress_smooth_data | |
| 74 JPP((j_decompress_ptr cinfo, JSAMPIMAGE output_buf)); | |
| 75 #endif | |
| 76 | |
| 77 | |
| 78 LOCAL(void) | |
| 79 start_iMCU_row (j_decompress_ptr cinfo) | |
| 80 /* Reset within-iMCU-row counters for a new row (input side) */ | |
| 81 { | |
| 82 my_coef_ptr coef = (my_coef_ptr) cinfo->coef; | |
| 83 | |
| 84 /* In an interleaved scan, an MCU row is the same as an iMCU row. | |
| 85 * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows. | |
| 86 * But at the bottom of the image, process only what's left. | |
| 87 */ | |
| 88 if (cinfo->comps_in_scan > 1) { | |
| 89 coef->MCU_rows_per_iMCU_row = 1; | |
| 90 } else { | |
| 91 if (cinfo->input_iMCU_row < (cinfo->total_iMCU_rows-1)) | |
| 92 coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor; | |
| 93 else | |
| 94 coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height; | |
| 95 } | |
| 96 | |
| 97 coef->MCU_ctr = 0; | |
| 98 coef->MCU_vert_offset = 0; | |
| 99 } | |
| 100 | |
| 101 | |
| 102 /* | |
| 103 * Initialize for an input processing pass. | |
| 104 */ | |
| 105 | |
| 106 METHODDEF(void) | |
| 107 start_input_pass (j_decompress_ptr cinfo) | |
| 108 { | |
| 109 cinfo->input_iMCU_row = 0; | |
| 110 start_iMCU_row(cinfo); | |
| 111 } | |
| 112 | |
| 113 | |
| 114 /* | |
| 115 * Initialize for an output processing pass. | |
| 116 */ | |
| 117 | |
| 118 METHODDEF(void) | |
| 119 start_output_pass (j_decompress_ptr cinfo) | |
| 120 { | |
| 121 #ifdef BLOCK_SMOOTHING_SUPPORTED | |
| 122 my_coef_ptr coef = (my_coef_ptr) cinfo->coef; | |
| 123 | |
| 124 /* If multipass, check to see whether to use block smoothing on this pass */ | |
| 125 if (coef->pub.coef_arrays != NULL) { | |
| 126 if (cinfo->do_block_smoothing && smoothing_ok(cinfo)) | |
| 127 coef->pub.decompress_data = decompress_smooth_data; | |
| 128 else | |
| 129 coef->pub.decompress_data = decompress_data; | |
| 130 } | |
| 131 #endif | |
| 132 cinfo->output_iMCU_row = 0; | |
| 133 } | |
| 134 | |
| 135 | |
| 136 /* | |
| 137 * Decompress and return some data in the single-pass case. | |
| 138 * Always attempts to emit one fully interleaved MCU row ("iMCU" row). | |
| 139 * Input and output must run in lockstep since we have only a one-MCU buffer. | |
| 140 * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED. | |
| 141 * | |
| 142 * NB: output_buf contains a plane for each component in image, | |
| 143 * which we index according to the component's SOF position. | |
| 144 */ | |
| 145 | |
| 146 METHODDEF(int) | |
| 147 decompress_onepass (j_decompress_ptr cinfo, JSAMPIMAGE output_buf) | |
| 148 { | |
| 149 my_coef_ptr coef = (my_coef_ptr) cinfo->coef; | |
| 150 JDIMENSION MCU_col_num; /* index of current MCU within row */ | |
| 151 JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1; | |
| 152 JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1; | |
| 153 int blkn, ci, xindex, yindex, yoffset, useful_width; | |
| 154 JSAMPARRAY output_ptr; | |
| 155 JDIMENSION start_col, output_col; | |
| 156 jpeg_component_info *compptr; | |
| 157 inverse_DCT_method_ptr inverse_DCT; | |
| 158 | |
| 159 /* Loop to process as much as one whole iMCU row */ | |
| 160 for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row; | |
| 161 yoffset++) { | |
| 162 for (MCU_col_num = coef->MCU_ctr; MCU_col_num <= last_MCU_col; | |
| 163 MCU_col_num++) { | |
| 164 /* Try to fetch an MCU. Entropy decoder expects buffer to be zeroed. */ | |
| 165 jzero_far((void FAR *) coef->MCU_buffer[0], | |
| 166 (size_t) (cinfo->blocks_in_MCU * SIZEOF(JBLOCK))); | |
| 167 if (! (*cinfo->entropy->decode_mcu) (cinfo, coef->MCU_buffer)) { | |
| 168 /* Suspension forced; update state counters and exit */ | |
| 169 coef->MCU_vert_offset = yoffset; | |
| 170 coef->MCU_ctr = MCU_col_num; | |
| 171 return JPEG_SUSPENDED; | |
| 172 } | |
| 173 /* Determine where data should go in output_buf and do the IDCT thing. | |
| 174 * We skip dummy blocks at the right and bottom edges (but blkn gets | |
| 175 * incremented past them!). Note the inner loop relies on having | |
| 176 * allocated the MCU_buffer[] blocks sequentially. | |
| 177 */ | |
| 178 blkn = 0; /* index of current DCT block within MCU */ | |
| 179 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { | |
| 180 compptr = cinfo->cur_comp_info[ci]; | |
| 181 /* Don't bother to IDCT an uninteresting component. */ | |
| 182 if (! compptr->component_needed) { | |
| 183 blkn += compptr->MCU_blocks; | |
| 184 continue; | |
| 185 } | |
| 186 inverse_DCT = cinfo->idct->inverse_DCT[compptr->component_index]; | |
| 187 useful_width = (MCU_col_num < last_MCU_col) ? compptr->MCU_width | |
| 188 : compptr->last_col_width; | |
| 189 output_ptr = output_buf[compptr->component_index] + | |
| 190 yoffset * compptr->DCT_scaled_size; | |
| 191 start_col = MCU_col_num * compptr->MCU_sample_width; | |
| 192 for (yindex = 0; yindex < compptr->MCU_height; yindex++) { | |
| 193 if (cinfo->input_iMCU_row < last_iMCU_row || | |
| 194 yoffset+yindex < compptr->last_row_height) { | |
| 195 output_col = start_col; | |
| 196 for (xindex = 0; xindex < useful_width; xindex++) { | |
| 197 (*inverse_DCT) (cinfo, compptr, | |
| 198 (JCOEFPTR) coef->MCU_buffer[blkn+xindex], | |
| 199 output_ptr, output_col); | |
| 200 output_col += compptr->DCT_scaled_size; | |
| 201 } | |
| 202 } | |
| 203 blkn += compptr->MCU_width; | |
| 204 output_ptr += compptr->DCT_scaled_size; | |
| 205 } | |
| 206 } | |
| 207 } | |
| 208 /* Completed an MCU row, but perhaps not an iMCU row */ | |
| 209 coef->MCU_ctr = 0; | |
| 210 } | |
| 211 /* Completed the iMCU row, advance counters for next one */ | |
| 212 cinfo->output_iMCU_row++; | |
| 213 if (++(cinfo->input_iMCU_row) < cinfo->total_iMCU_rows) { | |
| 214 start_iMCU_row(cinfo); | |
| 215 return JPEG_ROW_COMPLETED; | |
| 216 } | |
| 217 /* Completed the scan */ | |
| 218 (*cinfo->inputctl->finish_input_pass) (cinfo); | |
| 219 return JPEG_SCAN_COMPLETED; | |
| 220 } | |
| 221 | |
| 222 | |
| 223 /* | |
| 224 * Dummy consume-input routine for single-pass operation. | |
| 225 */ | |
| 226 | |
| 227 METHODDEF(int) | |
| 228 dummy_consume_data (j_decompress_ptr cinfo) | |
| 229 { | |
| 230 return JPEG_SUSPENDED; /* Always indicate nothing was done */ | |
| 231 } | |
| 232 | |
| 233 | |
| 234 #ifdef D_MULTISCAN_FILES_SUPPORTED | |
| 235 | |
| 236 /* | |
| 237 * Consume input data and store it in the full-image coefficient buffer. | |
| 238 * We read as much as one fully interleaved MCU row ("iMCU" row) per call, | |
| 239 * ie, v_samp_factor block rows for each component in the scan. | |
| 240 * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED. | |
| 241 */ | |
| 242 | |
| 243 METHODDEF(int) | |
| 244 consume_data (j_decompress_ptr cinfo) | |
| 245 { | |
| 246 my_coef_ptr coef = (my_coef_ptr) cinfo->coef; | |
| 247 JDIMENSION MCU_col_num; /* index of current MCU within row */ | |
| 248 int blkn, ci, xindex, yindex, yoffset; | |
| 249 JDIMENSION start_col; | |
| 250 JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN]; | |
| 251 JBLOCKROW buffer_ptr; | |
| 252 jpeg_component_info *compptr; | |
| 253 | |
| 254 /* Align the virtual buffers for the components used in this scan. */ | |
| 255 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { | |
| 256 compptr = cinfo->cur_comp_info[ci]; | |
| 257 buffer[ci] = (*cinfo->mem->access_virt_barray) | |
| 258 ((j_common_ptr) cinfo, coef->whole_image[compptr->component_index], | |
| 259 cinfo->input_iMCU_row * compptr->v_samp_factor, | |
| 260 (JDIMENSION) compptr->v_samp_factor, TRUE); | |
| 261 /* Note: entropy decoder expects buffer to be zeroed, | |
| 262 * but this is handled automatically by the memory manager | |
| 263 * because we requested a pre-zeroed array. | |
| 264 */ | |
| 265 } | |
| 266 | |
| 267 /* Loop to process one whole iMCU row */ | |
| 268 for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row; | |
| 269 yoffset++) { | |
| 270 for (MCU_col_num = coef->MCU_ctr; MCU_col_num < cinfo->MCUs_per_row; | |
| 271 MCU_col_num++) { | |
| 272 /* Construct list of pointers to DCT blocks belonging to this MCU */ | |
| 273 blkn = 0; /* index of current DCT block within MCU */ | |
| 274 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { | |
| 275 compptr = cinfo->cur_comp_info[ci]; | |
| 276 start_col = MCU_col_num * compptr->MCU_width; | |
| 277 for (yindex = 0; yindex < compptr->MCU_height; yindex++) { | |
| 278 buffer_ptr = buffer[ci][yindex+yoffset] + start_col; | |
| 279 for (xindex = 0; xindex < compptr->MCU_width; xindex++) { | |
| 280 coef->MCU_buffer[blkn++] = buffer_ptr++; | |
| 281 } | |
| 282 } | |
| 283 } | |
| 284 /* Try to fetch the MCU. */ | |
| 285 if (! (*cinfo->entropy->decode_mcu) (cinfo, coef->MCU_buffer)) { | |
| 286 /* Suspension forced; update state counters and exit */ | |
| 287 coef->MCU_vert_offset = yoffset; | |
| 288 coef->MCU_ctr = MCU_col_num; | |
| 289 return JPEG_SUSPENDED; | |
| 290 } | |
| 291 } | |
| 292 /* Completed an MCU row, but perhaps not an iMCU row */ | |
| 293 coef->MCU_ctr = 0; | |
| 294 } | |
| 295 /* Completed the iMCU row, advance counters for next one */ | |
| 296 if (++(cinfo->input_iMCU_row) < cinfo->total_iMCU_rows) { | |
| 297 start_iMCU_row(cinfo); | |
| 298 return JPEG_ROW_COMPLETED; | |
| 299 } | |
| 300 /* Completed the scan */ | |
| 301 (*cinfo->inputctl->finish_input_pass) (cinfo); | |
| 302 return JPEG_SCAN_COMPLETED; | |
| 303 } | |
| 304 | |
| 305 | |
| 306 /* | |
| 307 * Decompress and return some data in the multi-pass case. | |
| 308 * Always attempts to emit one fully interleaved MCU row ("iMCU" row). | |
| 309 * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED. | |
| 310 * | |
| 311 * NB: output_buf contains a plane for each component in image. | |
| 312 */ | |
| 313 | |
| 314 METHODDEF(int) | |
| 315 decompress_data (j_decompress_ptr cinfo, JSAMPIMAGE output_buf) | |
| 316 { | |
| 317 my_coef_ptr coef = (my_coef_ptr) cinfo->coef; | |
| 318 JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1; | |
| 319 JDIMENSION block_num; | |
| 320 int ci, block_row, block_rows; | |
| 321 JBLOCKARRAY buffer; | |
| 322 JBLOCKROW buffer_ptr; | |
| 323 JSAMPARRAY output_ptr; | |
| 324 JDIMENSION output_col; | |
| 325 jpeg_component_info *compptr; | |
| 326 inverse_DCT_method_ptr inverse_DCT; | |
| 327 | |
| 328 /* Force some input to be done if we are getting ahead of the input. */ | |
| 329 while (cinfo->input_scan_number < cinfo->output_scan_number || | |
| 330 (cinfo->input_scan_number == cinfo->output_scan_number && | |
| 331 cinfo->input_iMCU_row <= cinfo->output_iMCU_row)) { | |
| 332 if ((*cinfo->inputctl->consume_input)(cinfo) == JPEG_SUSPENDED) | |
| 333 return JPEG_SUSPENDED; | |
| 334 } | |
| 335 | |
| 336 /* OK, output from the virtual arrays. */ | |
| 337 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; | |
| 338 ci++, compptr++) { | |
| 339 /* Don't bother to IDCT an uninteresting component. */ | |
| 340 if (! compptr->component_needed) | |
| 341 continue; | |
| 342 /* Align the virtual buffer for this component. */ | |
| 343 buffer = (*cinfo->mem->access_virt_barray) | |
| 344 ((j_common_ptr) cinfo, coef->whole_image[ci], | |
| 345 cinfo->output_iMCU_row * compptr->v_samp_factor, | |
| 346 (JDIMENSION) compptr->v_samp_factor, FALSE); | |
| 347 /* Count non-dummy DCT block rows in this iMCU row. */ | |
| 348 if (cinfo->output_iMCU_row < last_iMCU_row) | |
| 349 block_rows = compptr->v_samp_factor; | |
| 350 else { | |
| 351 /* NB: can't use last_row_height here; it is input-side-dependent! */ | |
| 352 block_rows = (int) (compptr->height_in_blocks % compptr->v_samp_factor); | |
| 353 if (block_rows == 0) block_rows = compptr->v_samp_factor; | |
| 354 } | |
| 355 inverse_DCT = cinfo->idct->inverse_DCT[ci]; | |
| 356 output_ptr = output_buf[ci]; | |
| 357 /* Loop over all DCT blocks to be processed. */ | |
| 358 for (block_row = 0; block_row < block_rows; block_row++) { | |
| 359 buffer_ptr = buffer[block_row]; | |
| 360 output_col = 0; | |
| 361 for (block_num = 0; block_num < compptr->width_in_blocks; block_num++) { | |
| 362 (*inverse_DCT) (cinfo, compptr, (JCOEFPTR) buffer_ptr, | |
| 363 output_ptr, output_col); | |
| 364 buffer_ptr++; | |
| 365 output_col += compptr->DCT_scaled_size; | |
| 366 } | |
| 367 output_ptr += compptr->DCT_scaled_size; | |
| 368 } | |
| 369 } | |
| 370 | |
| 371 if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows) | |
| 372 return JPEG_ROW_COMPLETED; | |
| 373 return JPEG_SCAN_COMPLETED; | |
| 374 } | |
| 375 | |
| 376 #endif /* D_MULTISCAN_FILES_SUPPORTED */ | |
| 377 | |
| 378 | |
| 379 #ifdef BLOCK_SMOOTHING_SUPPORTED | |
| 380 | |
| 381 /* | |
| 382 * This code applies interblock smoothing as described by section K.8 | |
| 383 * of the JPEG standard: the first 5 AC coefficients are estimated from | |
| 384 * the DC values of a DCT block and its 8 neighboring blocks. | |
| 385 * We apply smoothing only for progressive JPEG decoding, and only if | |
| 386 * the coefficients it can estimate are not yet known to full precision. | |
| 387 */ | |
| 388 | |
| 389 /* Natural-order array positions of the first 5 zigzag-order coefficients */ | |
| 390 #define Q01_POS 1 | |
| 391 #define Q10_POS 8 | |
| 392 #define Q20_POS 16 | |
| 393 #define Q11_POS 9 | |
| 394 #define Q02_POS 2 | |
| 395 | |
| 396 /* | |
| 397 * Determine whether block smoothing is applicable and safe. | |
| 398 * We also latch the current states of the coef_bits[] entries for the | |
| 399 * AC coefficients; otherwise, if the input side of the decompressor | |
| 400 * advances into a new scan, we might think the coefficients are known | |
| 401 * more accurately than they really are. | |
| 402 */ | |
| 403 | |
| 404 LOCAL(boolean) | |
| 405 smoothing_ok (j_decompress_ptr cinfo) | |
| 406 { | |
| 407 my_coef_ptr coef = (my_coef_ptr) cinfo->coef; | |
| 408 boolean smoothing_useful = FALSE; | |
| 409 int ci, coefi; | |
| 410 jpeg_component_info *compptr; | |
| 411 JQUANT_TBL * qtable; | |
| 412 int * coef_bits; | |
| 413 int * coef_bits_latch; | |
| 414 | |
| 415 if (! cinfo->progressive_mode || cinfo->coef_bits == NULL) | |
| 416 return FALSE; | |
| 417 | |
| 418 /* Allocate latch area if not already done */ | |
| 419 if (coef->coef_bits_latch == NULL) | |
| 420 coef->coef_bits_latch = (int *) | |
| 421 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 422 cinfo->num_components * | |
| 423 (SAVED_COEFS * SIZEOF(int))); | |
| 424 coef_bits_latch = coef->coef_bits_latch; | |
| 425 | |
| 426 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; | |
| 427 ci++, compptr++) { | |
| 428 /* All components' quantization values must already be latched. */ | |
| 429 if ((qtable = compptr->quant_table) == NULL) | |
| 430 return FALSE; | |
| 431 /* Verify DC & first 5 AC quantizers are nonzero to avoid zero-divide. */ | |
| 432 if (qtable->quantval[0] == 0 || | |
| 433 qtable->quantval[Q01_POS] == 0 || | |
| 434 qtable->quantval[Q10_POS] == 0 || | |
| 435 qtable->quantval[Q20_POS] == 0 || | |
| 436 qtable->quantval[Q11_POS] == 0 || | |
| 437 qtable->quantval[Q02_POS] == 0) | |
| 438 return FALSE; | |
| 439 /* DC values must be at least partly known for all components. */ | |
| 440 coef_bits = cinfo->coef_bits[ci]; | |
| 441 if (coef_bits[0] < 0) | |
| 442 return FALSE; | |
| 443 /* Block smoothing is helpful if some AC coefficients remain inaccurate. */ | |
| 444 for (coefi = 1; coefi <= 5; coefi++) { | |
| 445 coef_bits_latch[coefi] = coef_bits[coefi]; | |
| 446 if (coef_bits[coefi] != 0) | |
| 447 smoothing_useful = TRUE; | |
| 448 } | |
| 449 coef_bits_latch += SAVED_COEFS; | |
| 450 } | |
| 451 | |
| 452 return smoothing_useful; | |
| 453 } | |
| 454 | |
| 455 | |
| 456 /* | |
| 457 * Variant of decompress_data for use when doing block smoothing. | |
| 458 */ | |
| 459 | |
| 460 METHODDEF(int) | |
| 461 decompress_smooth_data (j_decompress_ptr cinfo, JSAMPIMAGE output_buf) | |
| 462 { | |
| 463 my_coef_ptr coef = (my_coef_ptr) cinfo->coef; | |
| 464 JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1; | |
| 465 JDIMENSION block_num, last_block_column; | |
| 466 int ci, block_row, block_rows, access_rows; | |
| 467 JBLOCKARRAY buffer; | |
| 468 JBLOCKROW buffer_ptr, prev_block_row, next_block_row; | |
| 469 JSAMPARRAY output_ptr; | |
| 470 JDIMENSION output_col; | |
| 471 jpeg_component_info *compptr; | |
| 472 inverse_DCT_method_ptr inverse_DCT; | |
| 473 boolean first_row, last_row; | |
| 474 JBLOCK workspace; | |
| 475 int *coef_bits; | |
| 476 JQUANT_TBL *quanttbl; | |
| 477 INT32 Q00,Q01,Q02,Q10,Q11,Q20, num; | |
| 478 int DC1,DC2,DC3,DC4,DC5,DC6,DC7,DC8,DC9; | |
| 479 int Al, pred; | |
| 480 | |
| 481 /* Force some input to be done if we are getting ahead of the input. */ | |
| 482 while (cinfo->input_scan_number <= cinfo->output_scan_number && | |
| 483 ! cinfo->inputctl->eoi_reached) { | |
| 484 if (cinfo->input_scan_number == cinfo->output_scan_number) { | |
| 485 /* If input is working on current scan, we ordinarily want it to | |
| 486 * have completed the current row. But if input scan is DC, | |
| 487 * we want it to keep one row ahead so that next block row's DC | |
| 488 * values are up to date. | |
| 489 */ | |
| 490 JDIMENSION delta = (cinfo->Ss == 0) ? 1 : 0; | |
| 491 if (cinfo->input_iMCU_row > cinfo->output_iMCU_row+delta) | |
| 492 break; | |
| 493 } | |
| 494 if ((*cinfo->inputctl->consume_input)(cinfo) == JPEG_SUSPENDED) | |
| 495 return JPEG_SUSPENDED; | |
| 496 } | |
| 497 | |
| 498 /* OK, output from the virtual arrays. */ | |
| 499 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; | |
| 500 ci++, compptr++) { | |
| 501 /* Don't bother to IDCT an uninteresting component. */ | |
| 502 if (! compptr->component_needed) | |
| 503 continue; | |
| 504 /* Count non-dummy DCT block rows in this iMCU row. */ | |
| 505 if (cinfo->output_iMCU_row < last_iMCU_row) { | |
| 506 block_rows = compptr->v_samp_factor; | |
| 507 access_rows = block_rows * 2; /* this and next iMCU row */ | |
| 508 last_row = FALSE; | |
| 509 } else { | |
| 510 /* NB: can't use last_row_height here; it is input-side-dependent! */ | |
| 511 block_rows = (int) (compptr->height_in_blocks % compptr->v_samp_factor); | |
| 512 if (block_rows == 0) block_rows = compptr->v_samp_factor; | |
| 513 access_rows = block_rows; /* this iMCU row only */ | |
| 514 last_row = TRUE; | |
| 515 } | |
| 516 /* Align the virtual buffer for this component. */ | |
| 517 if (cinfo->output_iMCU_row > 0) { | |
| 518 access_rows += compptr->v_samp_factor; /* prior iMCU row too */ | |
| 519 buffer = (*cinfo->mem->access_virt_barray) | |
| 520 ((j_common_ptr) cinfo, coef->whole_image[ci], | |
| 521 (cinfo->output_iMCU_row - 1) * compptr->v_samp_factor, | |
| 522 (JDIMENSION) access_rows, FALSE); | |
| 523 buffer += compptr->v_samp_factor; /* point to current iMCU row */ | |
| 524 first_row = FALSE; | |
| 525 } else { | |
| 526 buffer = (*cinfo->mem->access_virt_barray) | |
| 527 ((j_common_ptr) cinfo, coef->whole_image[ci], | |
| 528 (JDIMENSION) 0, (JDIMENSION) access_rows, FALSE); | |
| 529 first_row = TRUE; | |
| 530 } | |
| 531 /* Fetch component-dependent info */ | |
| 532 coef_bits = coef->coef_bits_latch + (ci * SAVED_COEFS); | |
| 533 quanttbl = compptr->quant_table; | |
| 534 Q00 = quanttbl->quantval[0]; | |
| 535 Q01 = quanttbl->quantval[Q01_POS]; | |
| 536 Q10 = quanttbl->quantval[Q10_POS]; | |
| 537 Q20 = quanttbl->quantval[Q20_POS]; | |
| 538 Q11 = quanttbl->quantval[Q11_POS]; | |
| 539 Q02 = quanttbl->quantval[Q02_POS]; | |
| 540 inverse_DCT = cinfo->idct->inverse_DCT[ci]; | |
| 541 output_ptr = output_buf[ci]; | |
| 542 /* Loop over all DCT blocks to be processed. */ | |
| 543 for (block_row = 0; block_row < block_rows; block_row++) { | |
| 544 buffer_ptr = buffer[block_row]; | |
| 545 if (first_row && block_row == 0) | |
| 546 prev_block_row = buffer_ptr; | |
| 547 else | |
| 548 prev_block_row = buffer[block_row-1]; | |
| 549 if (last_row && block_row == block_rows-1) | |
| 550 next_block_row = buffer_ptr; | |
| 551 else | |
| 552 next_block_row = buffer[block_row+1]; | |
| 553 /* We fetch the surrounding DC values using a sliding-register approach. | |
| 554 * Initialize all nine here so as to do the right thing on narrow pics. | |
| 555 */ | |
| 556 DC1 = DC2 = DC3 = (int) prev_block_row[0][0]; | |
| 557 DC4 = DC5 = DC6 = (int) buffer_ptr[0][0]; | |
| 558 DC7 = DC8 = DC9 = (int) next_block_row[0][0]; | |
| 559 output_col = 0; | |
| 560 last_block_column = compptr->width_in_blocks - 1; | |
| 561 for (block_num = 0; block_num <= last_block_column; block_num++) { | |
| 562 /* Fetch current DCT block into workspace so we can modify it. */ | |
| 563 jcopy_block_row(buffer_ptr, (JBLOCKROW) workspace, (JDIMENSION) 1); | |
| 564 /* Update DC values */ | |
| 565 if (block_num < last_block_column) { | |
| 566 DC3 = (int) prev_block_row[1][0]; | |
| 567 DC6 = (int) buffer_ptr[1][0]; | |
| 568 DC9 = (int) next_block_row[1][0]; | |
| 569 } | |
| 570 /* Compute coefficient estimates per K.8. | |
| 571 * An estimate is applied only if coefficient is still zero, | |
| 572 * and is not known to be fully accurate. | |
| 573 */ | |
| 574 /* AC01 */ | |
| 575 if ((Al=coef_bits[1]) != 0 && workspace[1] == 0) { | |
| 576 num = 36 * Q00 * (DC4 - DC6); | |
| 577 if (num >= 0) { | |
| 578 pred = (int) (((Q01<<7) + num) / (Q01<<8)); | |
| 579 if (Al > 0 && pred >= (1<<Al)) | |
| 580 pred = (1<<Al)-1; | |
| 581 } else { | |
| 582 pred = (int) (((Q01<<7) - num) / (Q01<<8)); | |
| 583 if (Al > 0 && pred >= (1<<Al)) | |
| 584 pred = (1<<Al)-1; | |
| 585 pred = -pred; | |
| 586 } | |
| 587 workspace[1] = (JCOEF) pred; | |
| 588 } | |
| 589 /* AC10 */ | |
| 590 if ((Al=coef_bits[2]) != 0 && workspace[8] == 0) { | |
| 591 num = 36 * Q00 * (DC2 - DC8); | |
| 592 if (num >= 0) { | |
| 593 pred = (int) (((Q10<<7) + num) / (Q10<<8)); | |
| 594 if (Al > 0 && pred >= (1<<Al)) | |
| 595 pred = (1<<Al)-1; | |
| 596 } else { | |
| 597 pred = (int) (((Q10<<7) - num) / (Q10<<8)); | |
| 598 if (Al > 0 && pred >= (1<<Al)) | |
| 599 pred = (1<<Al)-1; | |
| 600 pred = -pred; | |
| 601 } | |
| 602 workspace[8] = (JCOEF) pred; | |
| 603 } | |
| 604 /* AC20 */ | |
| 605 if ((Al=coef_bits[3]) != 0 && workspace[16] == 0) { | |
| 606 num = 9 * Q00 * (DC2 + DC8 - 2*DC5); | |
| 607 if (num >= 0) { | |
| 608 pred = (int) (((Q20<<7) + num) / (Q20<<8)); | |
| 609 if (Al > 0 && pred >= (1<<Al)) | |
| 610 pred = (1<<Al)-1; | |
| 611 } else { | |
| 612 pred = (int) (((Q20<<7) - num) / (Q20<<8)); | |
| 613 if (Al > 0 && pred >= (1<<Al)) | |
| 614 pred = (1<<Al)-1; | |
| 615 pred = -pred; | |
| 616 } | |
| 617 workspace[16] = (JCOEF) pred; | |
| 618 } | |
| 619 /* AC11 */ | |
| 620 if ((Al=coef_bits[4]) != 0 && workspace[9] == 0) { | |
| 621 num = 5 * Q00 * (DC1 - DC3 - DC7 + DC9); | |
| 622 if (num >= 0) { | |
| 623 pred = (int) (((Q11<<7) + num) / (Q11<<8)); | |
| 624 if (Al > 0 && pred >= (1<<Al)) | |
| 625 pred = (1<<Al)-1; | |
| 626 } else { | |
| 627 pred = (int) (((Q11<<7) - num) / (Q11<<8)); | |
| 628 if (Al > 0 && pred >= (1<<Al)) | |
| 629 pred = (1<<Al)-1; | |
| 630 pred = -pred; | |
| 631 } | |
| 632 workspace[9] = (JCOEF) pred; | |
| 633 } | |
| 634 /* AC02 */ | |
| 635 if ((Al=coef_bits[5]) != 0 && workspace[2] == 0) { | |
| 636 num = 9 * Q00 * (DC4 + DC6 - 2*DC5); | |
| 637 if (num >= 0) { | |
| 638 pred = (int) (((Q02<<7) + num) / (Q02<<8)); | |
| 639 if (Al > 0 && pred >= (1<<Al)) | |
| 640 pred = (1<<Al)-1; | |
| 641 } else { | |
| 642 pred = (int) (((Q02<<7) - num) / (Q02<<8)); | |
| 643 if (Al > 0 && pred >= (1<<Al)) | |
| 644 pred = (1<<Al)-1; | |
| 645 pred = -pred; | |
| 646 } | |
| 647 workspace[2] = (JCOEF) pred; | |
| 648 } | |
| 649 /* OK, do the IDCT */ | |
| 650 (*inverse_DCT) (cinfo, compptr, (JCOEFPTR) workspace, | |
| 651 output_ptr, output_col); | |
| 652 /* Advance for next column */ | |
| 653 DC1 = DC2; DC2 = DC3; | |
| 654 DC4 = DC5; DC5 = DC6; | |
| 655 DC7 = DC8; DC8 = DC9; | |
| 656 buffer_ptr++, prev_block_row++, next_block_row++; | |
| 657 output_col += compptr->DCT_scaled_size; | |
| 658 } | |
| 659 output_ptr += compptr->DCT_scaled_size; | |
| 660 } | |
| 661 } | |
| 662 | |
| 663 if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows) | |
| 664 return JPEG_ROW_COMPLETED; | |
| 665 return JPEG_SCAN_COMPLETED; | |
| 666 } | |
| 667 | |
| 668 #endif /* BLOCK_SMOOTHING_SUPPORTED */ | |
| 669 | |
| 670 | |
| 671 /* | |
| 672 * Initialize coefficient buffer controller. | |
| 673 */ | |
| 674 | |
| 675 GLOBAL(void) | |
| 676 jinit_d_coef_controller (j_decompress_ptr cinfo, boolean need_full_buffer) | |
| 677 { | |
| 678 my_coef_ptr coef; | |
| 679 | |
| 680 coef = (my_coef_ptr) | |
| 681 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 682 SIZEOF(my_coef_controller)); | |
| 683 cinfo->coef = (struct jpeg_d_coef_controller *) coef; | |
| 684 coef->pub.start_input_pass = start_input_pass; | |
| 685 coef->pub.start_output_pass = start_output_pass; | |
| 686 #ifdef BLOCK_SMOOTHING_SUPPORTED | |
| 687 coef->coef_bits_latch = NULL; | |
| 688 #endif | |
| 689 | |
| 690 /* Create the coefficient buffer. */ | |
| 691 if (need_full_buffer) { | |
| 692 #ifdef D_MULTISCAN_FILES_SUPPORTED | |
| 693 /* Allocate a full-image virtual array for each component, */ | |
| 694 /* padded to a multiple of samp_factor DCT blocks in each direction. */ | |
| 695 /* Note we ask for a pre-zeroed array. */ | |
| 696 int ci, access_rows; | |
| 697 jpeg_component_info *compptr; | |
| 698 | |
| 699 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; | |
| 700 ci++, compptr++) { | |
| 701 access_rows = compptr->v_samp_factor; | |
| 702 #ifdef BLOCK_SMOOTHING_SUPPORTED | |
| 703 /* If block smoothing could be used, need a bigger window */ | |
| 704 if (cinfo->progressive_mode) | |
| 705 access_rows *= 3; | |
| 706 #endif | |
| 707 coef->whole_image[ci] = (*cinfo->mem->request_virt_barray) | |
| 708 ((j_common_ptr) cinfo, JPOOL_IMAGE, TRUE, | |
| 709 (JDIMENSION) jround_up((long) compptr->width_in_blocks, | |
| 710 (long) compptr->h_samp_factor), | |
| 711 (JDIMENSION) jround_up((long) compptr->height_in_blocks, | |
| 712 (long) compptr->v_samp_factor), | |
| 713 (JDIMENSION) access_rows); | |
| 714 } | |
| 715 coef->pub.consume_data = consume_data; | |
| 716 coef->pub.decompress_data = decompress_data; | |
| 717 coef->pub.coef_arrays = coef->whole_image; /* link to virtual arrays */ | |
| 718 #else | |
| 719 ERREXIT(cinfo, JERR_NOT_COMPILED); | |
| 720 #endif | |
| 721 } else { | |
| 722 /* We only need a single-MCU buffer. */ | |
| 723 JBLOCKROW buffer; | |
| 724 int i; | |
| 725 | |
| 726 buffer = (JBLOCKROW) | |
| 727 (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 728 D_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK)); | |
| 729 for (i = 0; i < D_MAX_BLOCKS_IN_MCU; i++) { | |
| 730 coef->MCU_buffer[i] = buffer + i; | |
| 731 } | |
| 732 coef->pub.consume_data = dummy_consume_data; | |
| 733 coef->pub.decompress_data = decompress_onepass; | |
| 734 coef->pub.coef_arrays = NULL; /* flag for no virtual arrays */ | |
| 735 } | |
| 736 } | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 1705523002:
Remove libjpeg and libjpeg_turbo. (Closed)
Base URL: https://github.com/domokit/mojo.git@master