| OLD | NEW |
|---|
| (Empty) |
| 1 /* | |
| 2 * jdmainct.c | |
| 3 * | |
| 4 * Copyright (C) 1994-1996, 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 main buffer controller for decompression. | |
| 9 * The main buffer lies between the JPEG decompressor proper and the | |
| 10 * post-processor; it holds downsampled data in the JPEG colorspace. | |
| 11 * | |
| 12 * Note that this code is bypassed in raw-data mode, since the application | |
| 13 * supplies the equivalent of the main buffer in that case. | |
| 14 */ | |
| 15 | |
| 16 #define JPEG_INTERNALS | |
| 17 #include "jinclude.h" | |
| 18 #include "jpeglib.h" | |
| 19 | |
| 20 | |
| 21 /* | |
| 22 * In the current system design, the main buffer need never be a full-image | |
| 23 * buffer; any full-height buffers will be found inside the coefficient or | |
| 24 * postprocessing controllers. Nonetheless, the main controller is not | |
| 25 * trivial. Its responsibility is to provide context rows for upsampling/ | |
| 26 * rescaling, and doing this in an efficient fashion is a bit tricky. | |
| 27 * | |
| 28 * Postprocessor input data is counted in "row groups". A row group | |
| 29 * is defined to be (v_samp_factor * DCT_scaled_size / min_DCT_scaled_size) | |
| 30 * sample rows of each component. (We require DCT_scaled_size values to be | |
| 31 * chosen such that these numbers are integers. In practice DCT_scaled_size | |
| 32 * values will likely be powers of two, so we actually have the stronger | |
| 33 * condition that DCT_scaled_size / min_DCT_scaled_size is an integer.) | |
| 34 * Upsampling will typically produce max_v_samp_factor pixel rows from each | |
| 35 * row group (times any additional scale factor that the upsampler is | |
| 36 * applying). | |
| 37 * | |
| 38 * The coefficient controller will deliver data to us one iMCU row at a time; | |
| 39 * each iMCU row contains v_samp_factor * DCT_scaled_size sample rows, or | |
| 40 * exactly min_DCT_scaled_size row groups. (This amount of data corresponds | |
| 41 * to one row of MCUs when the image is fully interleaved.) Note that the | |
| 42 * number of sample rows varies across components, but the number of row | |
| 43 * groups does not. Some garbage sample rows may be included in the last iMCU | |
| 44 * row at the bottom of the image. | |
| 45 * | |
| 46 * Depending on the vertical scaling algorithm used, the upsampler may need | |
| 47 * access to the sample row(s) above and below its current input row group. | |
| 48 * The upsampler is required to set need_context_rows TRUE at global selection | |
| 49 * time if so. When need_context_rows is FALSE, this controller can simply | |
| 50 * obtain one iMCU row at a time from the coefficient controller and dole it | |
| 51 * out as row groups to the postprocessor. | |
| 52 * | |
| 53 * When need_context_rows is TRUE, this controller guarantees that the buffer | |
| 54 * passed to postprocessing contains at least one row group's worth of samples | |
| 55 * above and below the row group(s) being processed. Note that the context | |
| 56 * rows "above" the first passed row group appear at negative row offsets in | |
| 57 * the passed buffer. At the top and bottom of the image, the required | |
| 58 * context rows are manufactured by duplicating the first or last real sample | |
| 59 * row; this avoids having special cases in the upsampling inner loops. | |
| 60 * | |
| 61 * The amount of context is fixed at one row group just because that's a | |
| 62 * convenient number for this controller to work with. The existing | |
| 63 * upsamplers really only need one sample row of context. An upsampler | |
| 64 * supporting arbitrary output rescaling might wish for more than one row | |
| 65 * group of context when shrinking the image; tough, we don't handle that. | |
| 66 * (This is justified by the assumption that downsizing will be handled mostly | |
| 67 * by adjusting the DCT_scaled_size values, so that the actual scale factor at | |
| 68 * the upsample step needn't be much less than one.) | |
| 69 * | |
| 70 * To provide the desired context, we have to retain the last two row groups | |
| 71 * of one iMCU row while reading in the next iMCU row. (The last row group | |
| 72 * can't be processed until we have another row group for its below-context, | |
| 73 * and so we have to save the next-to-last group too for its above-context.) | |
| 74 * We could do this most simply by copying data around in our buffer, but | |
| 75 * that'd be very slow. We can avoid copying any data by creating a rather | |
| 76 * strange pointer structure. Here's how it works. We allocate a workspace | |
| 77 * consisting of M+2 row groups (where M = min_DCT_scaled_size is the number | |
| 78 * of row groups per iMCU row). We create two sets of redundant pointers to | |
| 79 * the workspace. Labeling the physical row groups 0 to M+1, the synthesized | |
| 80 * pointer lists look like this: | |
| 81 * M+1 M-1 | |
| 82 * master pointer --> 0 master pointer --> 0 | |
| 83 * 1 1 | |
| 84 * ... ... | |
| 85 * M-3 M-3 | |
| 86 * M-2 M | |
| 87 * M-1 M+1 | |
| 88 * M M-2 | |
| 89 * M+1 M-1 | |
| 90 * 0 0 | |
| 91 * We read alternate iMCU rows using each master pointer; thus the last two | |
| 92 * row groups of the previous iMCU row remain un-overwritten in the workspace. | |
| 93 * The pointer lists are set up so that the required context rows appear to | |
| 94 * be adjacent to the proper places when we pass the pointer lists to the | |
| 95 * upsampler. | |
| 96 * | |
| 97 * The above pictures describe the normal state of the pointer lists. | |
| 98 * At top and bottom of the image, we diddle the pointer lists to duplicate | |
| 99 * the first or last sample row as necessary (this is cheaper than copying | |
| 100 * sample rows around). | |
| 101 * | |
| 102 * This scheme breaks down if M < 2, ie, min_DCT_scaled_size is 1. In that | |
| 103 * situation each iMCU row provides only one row group so the buffering logic | |
| 104 * must be different (eg, we must read two iMCU rows before we can emit the | |
| 105 * first row group). For now, we simply do not support providing context | |
| 106 * rows when min_DCT_scaled_size is 1. That combination seems unlikely to | |
| 107 * be worth providing --- if someone wants a 1/8th-size preview, they probably | |
| 108 * want it quick and dirty, so a context-free upsampler is sufficient. | |
| 109 */ | |
| 110 | |
| 111 | |
| 112 /* Private buffer controller object */ | |
| 113 | |
| 114 typedef struct { | |
| 115 struct jpeg_d_main_controller pub; /* public fields */ | |
| 116 | |
| 117 /* Pointer to allocated workspace (M or M+2 row groups). */ | |
| 118 JSAMPARRAY buffer[MAX_COMPONENTS]; | |
| 119 | |
| 120 boolean buffer_full; /* Have we gotten an iMCU row from decoder? */ | |
| 121 JDIMENSION rowgroup_ctr; /* counts row groups output to postprocessor */ | |
| 122 | |
| 123 /* Remaining fields are only used in the context case. */ | |
| 124 | |
| 125 /* These are the master pointers to the funny-order pointer lists. */ | |
| 126 JSAMPIMAGE xbuffer[2]; /* pointers to weird pointer lists */ | |
| 127 | |
| 128 int whichptr; /* indicates which pointer set is now in use */ | |
| 129 int context_state; /* process_data state machine status */ | |
| 130 JDIMENSION rowgroups_avail; /* row groups available to postprocessor */ | |
| 131 JDIMENSION iMCU_row_ctr; /* counts iMCU rows to detect image top/bot */ | |
| 132 } my_main_controller; | |
| 133 | |
| 134 typedef my_main_controller * my_main_ptr; | |
| 135 | |
| 136 /* context_state values: */ | |
| 137 #define CTX_PREPARE_FOR_IMCU 0 /* need to prepare for MCU row */ | |
| 138 #define CTX_PROCESS_IMCU 1 /* feeding iMCU to postprocessor */ | |
| 139 #define CTX_POSTPONED_ROW 2 /* feeding postponed row group */ | |
| 140 | |
| 141 | |
| 142 /* Forward declarations */ | |
| 143 METHODDEF(void) process_data_simple_main | |
| 144 JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf, | |
| 145 JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail)); | |
| 146 METHODDEF(void) process_data_context_main | |
| 147 JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf, | |
| 148 JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail)); | |
| 149 #ifdef QUANT_2PASS_SUPPORTED | |
| 150 METHODDEF(void) process_data_crank_post | |
| 151 JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf, | |
| 152 JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail)); | |
| 153 #endif | |
| 154 | |
| 155 | |
| 156 LOCAL(void) | |
| 157 alloc_funny_pointers (j_decompress_ptr cinfo) | |
| 158 /* Allocate space for the funny pointer lists. | |
| 159 * This is done only once, not once per pass. | |
| 160 */ | |
| 161 { | |
| 162 my_main_ptr main = (my_main_ptr) cinfo->main; | |
| 163 int ci, rgroup; | |
| 164 int M = cinfo->min_DCT_scaled_size; | |
| 165 jpeg_component_info *compptr; | |
| 166 JSAMPARRAY xbuf; | |
| 167 | |
| 168 /* Get top-level space for component array pointers. | |
| 169 * We alloc both arrays with one call to save a few cycles. | |
| 170 */ | |
| 171 main->xbuffer[0] = (JSAMPIMAGE) | |
| 172 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 173 cinfo->num_components * 2 * SIZEOF(JSAMPARRAY)); | |
| 174 main->xbuffer[1] = main->xbuffer[0] + cinfo->num_components; | |
| 175 | |
| 176 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; | |
| 177 ci++, compptr++) { | |
| 178 rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) / | |
| 179 cinfo->min_DCT_scaled_size; /* height of a row group of component */ | |
| 180 /* Get space for pointer lists --- M+4 row groups in each list. | |
| 181 * We alloc both pointer lists with one call to save a few cycles. | |
| 182 */ | |
| 183 xbuf = (JSAMPARRAY) | |
| 184 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 185 2 * (rgroup * (M + 4)) * SIZEOF(JSAMPROW)); | |
| 186 xbuf += rgroup; /* want one row group at negative offsets */ | |
| 187 main->xbuffer[0][ci] = xbuf; | |
| 188 xbuf += rgroup * (M + 4); | |
| 189 main->xbuffer[1][ci] = xbuf; | |
| 190 } | |
| 191 } | |
| 192 | |
| 193 | |
| 194 LOCAL(void) | |
| 195 make_funny_pointers (j_decompress_ptr cinfo) | |
| 196 /* Create the funny pointer lists discussed in the comments above. | |
| 197 * The actual workspace is already allocated (in main->buffer), | |
| 198 * and the space for the pointer lists is allocated too. | |
| 199 * This routine just fills in the curiously ordered lists. | |
| 200 * This will be repeated at the beginning of each pass. | |
| 201 */ | |
| 202 { | |
| 203 my_main_ptr main = (my_main_ptr) cinfo->main; | |
| 204 int ci, i, rgroup; | |
| 205 int M = cinfo->min_DCT_scaled_size; | |
| 206 jpeg_component_info *compptr; | |
| 207 JSAMPARRAY buf, xbuf0, xbuf1; | |
| 208 | |
| 209 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; | |
| 210 ci++, compptr++) { | |
| 211 rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) / | |
| 212 cinfo->min_DCT_scaled_size; /* height of a row group of component */ | |
| 213 xbuf0 = main->xbuffer[0][ci]; | |
| 214 xbuf1 = main->xbuffer[1][ci]; | |
| 215 /* First copy the workspace pointers as-is */ | |
| 216 buf = main->buffer[ci]; | |
| 217 for (i = 0; i < rgroup * (M + 2); i++) { | |
| 218 xbuf0[i] = xbuf1[i] = buf[i]; | |
| 219 } | |
| 220 /* In the second list, put the last four row groups in swapped order */ | |
| 221 for (i = 0; i < rgroup * 2; i++) { | |
| 222 xbuf1[rgroup*(M-2) + i] = buf[rgroup*M + i]; | |
| 223 xbuf1[rgroup*M + i] = buf[rgroup*(M-2) + i]; | |
| 224 } | |
| 225 /* The wraparound pointers at top and bottom will be filled later | |
| 226 * (see set_wraparound_pointers, below). Initially we want the "above" | |
| 227 * pointers to duplicate the first actual data line. This only needs | |
| 228 * to happen in xbuffer[0]. | |
| 229 */ | |
| 230 for (i = 0; i < rgroup; i++) { | |
| 231 xbuf0[i - rgroup] = xbuf0[0]; | |
| 232 } | |
| 233 } | |
| 234 } | |
| 235 | |
| 236 | |
| 237 LOCAL(void) | |
| 238 set_wraparound_pointers (j_decompress_ptr cinfo) | |
| 239 /* Set up the "wraparound" pointers at top and bottom of the pointer lists. | |
| 240 * This changes the pointer list state from top-of-image to the normal state. | |
| 241 */ | |
| 242 { | |
| 243 my_main_ptr main = (my_main_ptr) cinfo->main; | |
| 244 int ci, i, rgroup; | |
| 245 int M = cinfo->min_DCT_scaled_size; | |
| 246 jpeg_component_info *compptr; | |
| 247 JSAMPARRAY xbuf0, xbuf1; | |
| 248 | |
| 249 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; | |
| 250 ci++, compptr++) { | |
| 251 rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) / | |
| 252 cinfo->min_DCT_scaled_size; /* height of a row group of component */ | |
| 253 xbuf0 = main->xbuffer[0][ci]; | |
| 254 xbuf1 = main->xbuffer[1][ci]; | |
| 255 for (i = 0; i < rgroup; i++) { | |
| 256 xbuf0[i - rgroup] = xbuf0[rgroup*(M+1) + i]; | |
| 257 xbuf1[i - rgroup] = xbuf1[rgroup*(M+1) + i]; | |
| 258 xbuf0[rgroup*(M+2) + i] = xbuf0[i]; | |
| 259 xbuf1[rgroup*(M+2) + i] = xbuf1[i]; | |
| 260 } | |
| 261 } | |
| 262 } | |
| 263 | |
| 264 | |
| 265 LOCAL(void) | |
| 266 set_bottom_pointers (j_decompress_ptr cinfo) | |
| 267 /* Change the pointer lists to duplicate the last sample row at the bottom | |
| 268 * of the image. whichptr indicates which xbuffer holds the final iMCU row. | |
| 269 * Also sets rowgroups_avail to indicate number of nondummy row groups in row. | |
| 270 */ | |
| 271 { | |
| 272 my_main_ptr main = (my_main_ptr) cinfo->main; | |
| 273 int ci, i, rgroup, iMCUheight, rows_left; | |
| 274 jpeg_component_info *compptr; | |
| 275 JSAMPARRAY xbuf; | |
| 276 | |
| 277 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; | |
| 278 ci++, compptr++) { | |
| 279 /* Count sample rows in one iMCU row and in one row group */ | |
| 280 iMCUheight = compptr->v_samp_factor * compptr->DCT_scaled_size; | |
| 281 rgroup = iMCUheight / cinfo->min_DCT_scaled_size; | |
| 282 /* Count nondummy sample rows remaining for this component */ | |
| 283 rows_left = (int) (compptr->downsampled_height % (JDIMENSION) iMCUheight); | |
| 284 if (rows_left == 0) rows_left = iMCUheight; | |
| 285 /* Count nondummy row groups. Should get same answer for each component, | |
| 286 * so we need only do it once. | |
| 287 */ | |
| 288 if (ci == 0) { | |
| 289 main->rowgroups_avail = (JDIMENSION) ((rows_left-1) / rgroup + 1); | |
| 290 } | |
| 291 /* Duplicate the last real sample row rgroup*2 times; this pads out the | |
| 292 * last partial rowgroup and ensures at least one full rowgroup of context. | |
| 293 */ | |
| 294 xbuf = main->xbuffer[main->whichptr][ci]; | |
| 295 for (i = 0; i < rgroup * 2; i++) { | |
| 296 xbuf[rows_left + i] = xbuf[rows_left-1]; | |
| 297 } | |
| 298 } | |
| 299 } | |
| 300 | |
| 301 | |
| 302 /* | |
| 303 * Initialize for a processing pass. | |
| 304 */ | |
| 305 | |
| 306 METHODDEF(void) | |
| 307 start_pass_main (j_decompress_ptr cinfo, J_BUF_MODE pass_mode) | |
| 308 { | |
| 309 my_main_ptr main = (my_main_ptr) cinfo->main; | |
| 310 | |
| 311 switch (pass_mode) { | |
| 312 case JBUF_PASS_THRU: | |
| 313 if (cinfo->upsample->need_context_rows) { | |
| 314 main->pub.process_data = process_data_context_main; | |
| 315 make_funny_pointers(cinfo); /* Create the xbuffer[] lists */ | |
| 316 main->whichptr = 0; /* Read first iMCU row into xbuffer[0] */ | |
| 317 main->context_state = CTX_PREPARE_FOR_IMCU; | |
| 318 main->iMCU_row_ctr = 0; | |
| 319 } else { | |
| 320 /* Simple case with no context needed */ | |
| 321 main->pub.process_data = process_data_simple_main; | |
| 322 } | |
| 323 main->buffer_full = FALSE; /* Mark buffer empty */ | |
| 324 main->rowgroup_ctr = 0; | |
| 325 break; | |
| 326 #ifdef QUANT_2PASS_SUPPORTED | |
| 327 case JBUF_CRANK_DEST: | |
| 328 /* For last pass of 2-pass quantization, just crank the postprocessor */ | |
| 329 main->pub.process_data = process_data_crank_post; | |
| 330 break; | |
| 331 #endif | |
| 332 default: | |
| 333 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); | |
| 334 break; | |
| 335 } | |
| 336 } | |
| 337 | |
| 338 | |
| 339 /* | |
| 340 * Process some data. | |
| 341 * This handles the simple case where no context is required. | |
| 342 */ | |
| 343 | |
| 344 METHODDEF(void) | |
| 345 process_data_simple_main (j_decompress_ptr cinfo, | |
| 346 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
| 347 JDIMENSION out_rows_avail) | |
| 348 { | |
| 349 my_main_ptr main = (my_main_ptr) cinfo->main; | |
| 350 JDIMENSION rowgroups_avail; | |
| 351 | |
| 352 /* Read input data if we haven't filled the main buffer yet */ | |
| 353 if (! main->buffer_full) { | |
| 354 if (! (*cinfo->coef->decompress_data) (cinfo, main->buffer)) | |
| 355 return; /* suspension forced, can do nothing more */ | |
| 356 main->buffer_full = TRUE; /* OK, we have an iMCU row to work with */ | |
| 357 } | |
| 358 | |
| 359 /* There are always min_DCT_scaled_size row groups in an iMCU row. */ | |
| 360 rowgroups_avail = (JDIMENSION) cinfo->min_DCT_scaled_size; | |
| 361 /* Note: at the bottom of the image, we may pass extra garbage row groups | |
| 362 * to the postprocessor. The postprocessor has to check for bottom | |
| 363 * of image anyway (at row resolution), so no point in us doing it too. | |
| 364 */ | |
| 365 | |
| 366 /* Feed the postprocessor */ | |
| 367 (*cinfo->post->post_process_data) (cinfo, main->buffer, | |
| 368 &main->rowgroup_ctr, rowgroups_avail, | |
| 369 output_buf, out_row_ctr, out_rows_avail); | |
| 370 | |
| 371 /* Has postprocessor consumed all the data yet? If so, mark buffer empty */ | |
| 372 if (main->rowgroup_ctr >= rowgroups_avail) { | |
| 373 main->buffer_full = FALSE; | |
| 374 main->rowgroup_ctr = 0; | |
| 375 } | |
| 376 } | |
| 377 | |
| 378 | |
| 379 /* | |
| 380 * Process some data. | |
| 381 * This handles the case where context rows must be provided. | |
| 382 */ | |
| 383 | |
| 384 METHODDEF(void) | |
| 385 process_data_context_main (j_decompress_ptr cinfo, | |
| 386 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
| 387 JDIMENSION out_rows_avail) | |
| 388 { | |
| 389 my_main_ptr main = (my_main_ptr) cinfo->main; | |
| 390 | |
| 391 /* Read input data if we haven't filled the main buffer yet */ | |
| 392 if (! main->buffer_full) { | |
| 393 if (! (*cinfo->coef->decompress_data) (cinfo, | |
| 394 main->xbuffer[main->whichptr])) | |
| 395 return; /* suspension forced, can do nothing more */ | |
| 396 main->buffer_full = TRUE; /* OK, we have an iMCU row to work with */ | |
| 397 main->iMCU_row_ctr++; /* count rows received */ | |
| 398 } | |
| 399 | |
| 400 /* Postprocessor typically will not swallow all the input data it is handed | |
| 401 * in one call (due to filling the output buffer first). Must be prepared | |
| 402 * to exit and restart. This switch lets us keep track of how far we got. | |
| 403 * Note that each case falls through to the next on successful completion. | |
| 404 */ | |
| 405 switch (main->context_state) { | |
| 406 case CTX_POSTPONED_ROW: | |
| 407 /* Call postprocessor using previously set pointers for postponed row */ | |
| 408 (*cinfo->post->post_process_data) (cinfo, main->xbuffer[main->whichptr], | |
| 409 &main->rowgroup_ctr, main->rowgroups_avail, | |
| 410 output_buf, out_row_ctr, out_rows_avail); | |
| 411 if (main->rowgroup_ctr < main->rowgroups_avail) | |
| 412 return; /* Need to suspend */ | |
| 413 main->context_state = CTX_PREPARE_FOR_IMCU; | |
| 414 if (*out_row_ctr >= out_rows_avail) | |
| 415 return; /* Postprocessor exactly filled output buf */ | |
| 416 /*FALLTHROUGH*/ | |
| 417 case CTX_PREPARE_FOR_IMCU: | |
| 418 /* Prepare to process first M-1 row groups of this iMCU row */ | |
| 419 main->rowgroup_ctr = 0; | |
| 420 main->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_scaled_size - 1); | |
| 421 /* Check for bottom of image: if so, tweak pointers to "duplicate" | |
| 422 * the last sample row, and adjust rowgroups_avail to ignore padding rows. | |
| 423 */ | |
| 424 if (main->iMCU_row_ctr == cinfo->total_iMCU_rows) | |
| 425 set_bottom_pointers(cinfo); | |
| 426 main->context_state = CTX_PROCESS_IMCU; | |
| 427 /*FALLTHROUGH*/ | |
| 428 case CTX_PROCESS_IMCU: | |
| 429 /* Call postprocessor using previously set pointers */ | |
| 430 (*cinfo->post->post_process_data) (cinfo, main->xbuffer[main->whichptr], | |
| 431 &main->rowgroup_ctr, main->rowgroups_avail, | |
| 432 output_buf, out_row_ctr, out_rows_avail); | |
| 433 if (main->rowgroup_ctr < main->rowgroups_avail) | |
| 434 return; /* Need to suspend */ | |
| 435 /* After the first iMCU, change wraparound pointers to normal state */ | |
| 436 if (main->iMCU_row_ctr == 1) | |
| 437 set_wraparound_pointers(cinfo); | |
| 438 /* Prepare to load new iMCU row using other xbuffer list */ | |
| 439 main->whichptr ^= 1; /* 0=>1 or 1=>0 */ | |
| 440 main->buffer_full = FALSE; | |
| 441 /* Still need to process last row group of this iMCU row, */ | |
| 442 /* which is saved at index M+1 of the other xbuffer */ | |
| 443 main->rowgroup_ctr = (JDIMENSION) (cinfo->min_DCT_scaled_size + 1); | |
| 444 main->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_scaled_size + 2); | |
| 445 main->context_state = CTX_POSTPONED_ROW; | |
| 446 } | |
| 447 } | |
| 448 | |
| 449 | |
| 450 /* | |
| 451 * Process some data. | |
| 452 * Final pass of two-pass quantization: just call the postprocessor. | |
| 453 * Source data will be the postprocessor controller's internal buffer. | |
| 454 */ | |
| 455 | |
| 456 #ifdef QUANT_2PASS_SUPPORTED | |
| 457 | |
| 458 METHODDEF(void) | |
| 459 process_data_crank_post (j_decompress_ptr cinfo, | |
| 460 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
| 461 JDIMENSION out_rows_avail) | |
| 462 { | |
| 463 (*cinfo->post->post_process_data) (cinfo, (JSAMPIMAGE) NULL, | |
| 464 (JDIMENSION *) NULL, (JDIMENSION) 0, | |
| 465 output_buf, out_row_ctr, out_rows_avail); | |
| 466 } | |
| 467 | |
| 468 #endif /* QUANT_2PASS_SUPPORTED */ | |
| 469 | |
| 470 | |
| 471 /* | |
| 472 * Initialize main buffer controller. | |
| 473 */ | |
| 474 | |
| 475 GLOBAL(void) | |
| 476 jinit_d_main_controller (j_decompress_ptr cinfo, boolean need_full_buffer) | |
| 477 { | |
| 478 my_main_ptr main; | |
| 479 int ci, rgroup, ngroups; | |
| 480 jpeg_component_info *compptr; | |
| 481 | |
| 482 main = (my_main_ptr) | |
| 483 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 484 SIZEOF(my_main_controller)); | |
| 485 cinfo->main = (struct jpeg_d_main_controller *) main; | |
| 486 main->pub.start_pass = start_pass_main; | |
| 487 | |
| 488 if (need_full_buffer) /* shouldn't happen */ | |
| 489 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); | |
| 490 | |
| 491 /* Allocate the workspace. | |
| 492 * ngroups is the number of row groups we need. | |
| 493 */ | |
| 494 if (cinfo->upsample->need_context_rows) { | |
| 495 if (cinfo->min_DCT_scaled_size < 2) /* unsupported, see comments above */ | |
| 496 ERREXIT(cinfo, JERR_NOTIMPL); | |
| 497 alloc_funny_pointers(cinfo); /* Alloc space for xbuffer[] lists */ | |
| 498 ngroups = cinfo->min_DCT_scaled_size + 2; | |
| 499 } else { | |
| 500 ngroups = cinfo->min_DCT_scaled_size; | |
| 501 } | |
| 502 | |
| 503 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; | |
| 504 ci++, compptr++) { | |
| 505 rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) / | |
| 506 cinfo->min_DCT_scaled_size; /* height of a row group of component */ | |
| 507 main->buffer[ci] = (*cinfo->mem->alloc_sarray) | |
| 508 ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 509 compptr->width_in_blocks * compptr->DCT_scaled_size, | |
| 510 (JDIMENSION) (rgroup * ngroups)); | |
| 511 } | |
| 512 } | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 1705523002:
Remove libjpeg and libjpeg_turbo. (Closed)
Base URL: https://github.com/domokit/mojo.git@master