| OLD | NEW |
|---|
| (Empty) |
| 1 /* | |
| 2 * jdmerge.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 code for merged upsampling/color conversion. | |
| 9 * | |
| 10 * This file combines functions from jdsample.c and jdcolor.c; | |
| 11 * read those files first to understand what's going on. | |
| 12 * | |
| 13 * When the chroma components are to be upsampled by simple replication | |
| 14 * (ie, box filtering), we can save some work in color conversion by | |
| 15 * calculating all the output pixels corresponding to a pair of chroma | |
| 16 * samples at one time. In the conversion equations | |
| 17 * R = Y + K1 * Cr | |
| 18 * G = Y + K2 * Cb + K3 * Cr | |
| 19 * B = Y + K4 * Cb | |
| 20 * only the Y term varies among the group of pixels corresponding to a pair | |
| 21 * of chroma samples, so the rest of the terms can be calculated just once. | |
| 22 * At typical sampling ratios, this eliminates half or three-quarters of the | |
| 23 * multiplications needed for color conversion. | |
| 24 * | |
| 25 * This file currently provides implementations for the following cases: | |
| 26 * YCbCr => RGB color conversion only. | |
| 27 * Sampling ratios of 2h1v or 2h2v. | |
| 28 * No scaling needed at upsample time. | |
| 29 * Corner-aligned (non-CCIR601) sampling alignment. | |
| 30 * Other special cases could be added, but in most applications these are | |
| 31 * the only common cases. (For uncommon cases we fall back on the more | |
| 32 * general code in jdsample.c and jdcolor.c.) | |
| 33 */ | |
| 34 | |
| 35 #define JPEG_INTERNALS | |
| 36 #include "jinclude.h" | |
| 37 #include "jpeglib.h" | |
| 38 | |
| 39 #ifdef UPSAMPLE_MERGING_SUPPORTED | |
| 40 | |
| 41 | |
| 42 /* Private subobject */ | |
| 43 | |
| 44 typedef struct { | |
| 45 struct jpeg_upsampler pub; /* public fields */ | |
| 46 | |
| 47 /* Pointer to routine to do actual upsampling/conversion of one row group */ | |
| 48 JMETHOD(void, upmethod, (j_decompress_ptr cinfo, | |
| 49 JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr, | |
| 50 JSAMPARRAY output_buf)); | |
| 51 | |
| 52 /* Private state for YCC->RGB conversion */ | |
| 53 int * Cr_r_tab; /* => table for Cr to R conversion */ | |
| 54 int * Cb_b_tab; /* => table for Cb to B conversion */ | |
| 55 INT32 * Cr_g_tab; /* => table for Cr to G conversion */ | |
| 56 INT32 * Cb_g_tab; /* => table for Cb to G conversion */ | |
| 57 | |
| 58 /* For 2:1 vertical sampling, we produce two output rows at a time. | |
| 59 * We need a "spare" row buffer to hold the second output row if the | |
| 60 * application provides just a one-row buffer; we also use the spare | |
| 61 * to discard the dummy last row if the image height is odd. | |
| 62 */ | |
| 63 JSAMPROW spare_row; | |
| 64 boolean spare_full; /* T if spare buffer is occupied */ | |
| 65 | |
| 66 JDIMENSION out_row_width; /* samples per output row */ | |
| 67 JDIMENSION rows_to_go; /* counts rows remaining in image */ | |
| 68 } my_upsampler; | |
| 69 | |
| 70 typedef my_upsampler * my_upsample_ptr; | |
| 71 | |
| 72 #define SCALEBITS 16 /* speediest right-shift on some machines */ | |
| 73 #define ONE_HALF ((INT32) 1 << (SCALEBITS-1)) | |
| 74 #define FIX(x) ((INT32) ((x) * (1L<<SCALEBITS) + 0.5)) | |
| 75 | |
| 76 | |
| 77 /* | |
| 78 * Initialize tables for YCC->RGB colorspace conversion. | |
| 79 * This is taken directly from jdcolor.c; see that file for more info. | |
| 80 */ | |
| 81 | |
| 82 LOCAL(void) | |
| 83 build_ycc_rgb_table (j_decompress_ptr cinfo) | |
| 84 { | |
| 85 my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample; | |
| 86 int i; | |
| 87 INT32 x; | |
| 88 SHIFT_TEMPS | |
| 89 | |
| 90 upsample->Cr_r_tab = (int *) | |
| 91 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 92 (MAXJSAMPLE+1) * SIZEOF(int)); | |
| 93 upsample->Cb_b_tab = (int *) | |
| 94 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 95 (MAXJSAMPLE+1) * SIZEOF(int)); | |
| 96 upsample->Cr_g_tab = (INT32 *) | |
| 97 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 98 (MAXJSAMPLE+1) * SIZEOF(INT32)); | |
| 99 upsample->Cb_g_tab = (INT32 *) | |
| 100 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 101 (MAXJSAMPLE+1) * SIZEOF(INT32)); | |
| 102 | |
| 103 for (i = 0, x = -CENTERJSAMPLE; i <= MAXJSAMPLE; i++, x++) { | |
| 104 /* i is the actual input pixel value, in the range 0..MAXJSAMPLE */ | |
| 105 /* The Cb or Cr value we are thinking of is x = i - CENTERJSAMPLE */ | |
| 106 /* Cr=>R value is nearest int to 1.40200 * x */ | |
| 107 upsample->Cr_r_tab[i] = (int) | |
| 108 RIGHT_SHIFT(FIX(1.40200) * x + ONE_HALF, SCALEBITS); | |
| 109 /* Cb=>B value is nearest int to 1.77200 * x */ | |
| 110 upsample->Cb_b_tab[i] = (int) | |
| 111 RIGHT_SHIFT(FIX(1.77200) * x + ONE_HALF, SCALEBITS); | |
| 112 /* Cr=>G value is scaled-up -0.71414 * x */ | |
| 113 upsample->Cr_g_tab[i] = (- FIX(0.71414)) * x; | |
| 114 /* Cb=>G value is scaled-up -0.34414 * x */ | |
| 115 /* We also add in ONE_HALF so that need not do it in inner loop */ | |
| 116 upsample->Cb_g_tab[i] = (- FIX(0.34414)) * x + ONE_HALF; | |
| 117 } | |
| 118 } | |
| 119 | |
| 120 | |
| 121 /* | |
| 122 * Initialize for an upsampling pass. | |
| 123 */ | |
| 124 | |
| 125 METHODDEF(void) | |
| 126 start_pass_merged_upsample (j_decompress_ptr cinfo) | |
| 127 { | |
| 128 my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample; | |
| 129 | |
| 130 /* Mark the spare buffer empty */ | |
| 131 upsample->spare_full = FALSE; | |
| 132 /* Initialize total-height counter for detecting bottom of image */ | |
| 133 upsample->rows_to_go = cinfo->output_height; | |
| 134 } | |
| 135 | |
| 136 | |
| 137 /* | |
| 138 * Control routine to do upsampling (and color conversion). | |
| 139 * | |
| 140 * The control routine just handles the row buffering considerations. | |
| 141 */ | |
| 142 | |
| 143 METHODDEF(void) | |
| 144 merged_2v_upsample (j_decompress_ptr cinfo, | |
| 145 JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, | |
| 146 JDIMENSION in_row_groups_avail, | |
| 147 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
| 148 JDIMENSION out_rows_avail) | |
| 149 /* 2:1 vertical sampling case: may need a spare row. */ | |
| 150 { | |
| 151 my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample; | |
| 152 JSAMPROW work_ptrs[2]; | |
| 153 JDIMENSION num_rows; /* number of rows returned to caller */ | |
| 154 | |
| 155 if (upsample->spare_full) { | |
| 156 /* If we have a spare row saved from a previous cycle, just return it. */ | |
| 157 jcopy_sample_rows(& upsample->spare_row, 0, output_buf + *out_row_ctr, 0, | |
| 158 1, upsample->out_row_width); | |
| 159 num_rows = 1; | |
| 160 upsample->spare_full = FALSE; | |
| 161 } else { | |
| 162 /* Figure number of rows to return to caller. */ | |
| 163 num_rows = 2; | |
| 164 /* Not more than the distance to the end of the image. */ | |
| 165 if (num_rows > upsample->rows_to_go) | |
| 166 num_rows = upsample->rows_to_go; | |
| 167 /* And not more than what the client can accept: */ | |
| 168 out_rows_avail -= *out_row_ctr; | |
| 169 if (num_rows > out_rows_avail) | |
| 170 num_rows = out_rows_avail; | |
| 171 /* Create output pointer array for upsampler. */ | |
| 172 work_ptrs[0] = output_buf[*out_row_ctr]; | |
| 173 if (num_rows > 1) { | |
| 174 work_ptrs[1] = output_buf[*out_row_ctr + 1]; | |
| 175 } else { | |
| 176 work_ptrs[1] = upsample->spare_row; | |
| 177 upsample->spare_full = TRUE; | |
| 178 } | |
| 179 /* Now do the upsampling. */ | |
| 180 (*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr, work_ptrs); | |
| 181 } | |
| 182 | |
| 183 /* Adjust counts */ | |
| 184 *out_row_ctr += num_rows; | |
| 185 upsample->rows_to_go -= num_rows; | |
| 186 /* When the buffer is emptied, declare this input row group consumed */ | |
| 187 if (! upsample->spare_full) | |
| 188 (*in_row_group_ctr)++; | |
| 189 } | |
| 190 | |
| 191 | |
| 192 METHODDEF(void) | |
| 193 merged_1v_upsample (j_decompress_ptr cinfo, | |
| 194 JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, | |
| 195 JDIMENSION in_row_groups_avail, | |
| 196 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
| 197 JDIMENSION out_rows_avail) | |
| 198 /* 1:1 vertical sampling case: much easier, never need a spare row. */ | |
| 199 { | |
| 200 my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample; | |
| 201 | |
| 202 /* Just do the upsampling. */ | |
| 203 (*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr, | |
| 204 output_buf + *out_row_ctr); | |
| 205 /* Adjust counts */ | |
| 206 (*out_row_ctr)++; | |
| 207 (*in_row_group_ctr)++; | |
| 208 } | |
| 209 | |
| 210 | |
| 211 /* | |
| 212 * These are the routines invoked by the control routines to do | |
| 213 * the actual upsampling/conversion. One row group is processed per call. | |
| 214 * | |
| 215 * Note: since we may be writing directly into application-supplied buffers, | |
| 216 * we have to be honest about the output width; we can't assume the buffer | |
| 217 * has been rounded up to an even width. | |
| 218 */ | |
| 219 | |
| 220 | |
| 221 /* | |
| 222 * Upsample and color convert for the case of 2:1 horizontal and 1:1 vertical. | |
| 223 */ | |
| 224 | |
| 225 METHODDEF(void) | |
| 226 h2v1_merged_upsample (j_decompress_ptr cinfo, | |
| 227 JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr, | |
| 228 JSAMPARRAY output_buf) | |
| 229 { | |
| 230 my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample; | |
| 231 register int y, cred, cgreen, cblue; | |
| 232 int cb, cr; | |
| 233 register JSAMPROW outptr; | |
| 234 JSAMPROW inptr0, inptr1, inptr2; | |
| 235 JDIMENSION col; | |
| 236 /* copy these pointers into registers if possible */ | |
| 237 register JSAMPLE * range_limit = cinfo->sample_range_limit; | |
| 238 int * Crrtab = upsample->Cr_r_tab; | |
| 239 int * Cbbtab = upsample->Cb_b_tab; | |
| 240 INT32 * Crgtab = upsample->Cr_g_tab; | |
| 241 INT32 * Cbgtab = upsample->Cb_g_tab; | |
| 242 SHIFT_TEMPS | |
| 243 | |
| 244 inptr0 = input_buf[0][in_row_group_ctr]; | |
| 245 inptr1 = input_buf[1][in_row_group_ctr]; | |
| 246 inptr2 = input_buf[2][in_row_group_ctr]; | |
| 247 outptr = output_buf[0]; | |
| 248 /* Loop for each pair of output pixels */ | |
| 249 for (col = cinfo->output_width >> 1; col > 0; col--) { | |
| 250 /* Do the chroma part of the calculation */ | |
| 251 cb = GETJSAMPLE(*inptr1++); | |
| 252 cr = GETJSAMPLE(*inptr2++); | |
| 253 cred = Crrtab[cr]; | |
| 254 cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS); | |
| 255 cblue = Cbbtab[cb]; | |
| 256 /* Fetch 2 Y values and emit 2 pixels */ | |
| 257 y = GETJSAMPLE(*inptr0++); | |
| 258 outptr[RGB_RED] = range_limit[y + cred]; | |
| 259 outptr[RGB_GREEN] = range_limit[y + cgreen]; | |
| 260 outptr[RGB_BLUE] = range_limit[y + cblue]; | |
| 261 outptr += RGB_PIXELSIZE; | |
| 262 y = GETJSAMPLE(*inptr0++); | |
| 263 outptr[RGB_RED] = range_limit[y + cred]; | |
| 264 outptr[RGB_GREEN] = range_limit[y + cgreen]; | |
| 265 outptr[RGB_BLUE] = range_limit[y + cblue]; | |
| 266 outptr += RGB_PIXELSIZE; | |
| 267 } | |
| 268 /* If image width is odd, do the last output column separately */ | |
| 269 if (cinfo->output_width & 1) { | |
| 270 cb = GETJSAMPLE(*inptr1); | |
| 271 cr = GETJSAMPLE(*inptr2); | |
| 272 cred = Crrtab[cr]; | |
| 273 cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS); | |
| 274 cblue = Cbbtab[cb]; | |
| 275 y = GETJSAMPLE(*inptr0); | |
| 276 outptr[RGB_RED] = range_limit[y + cred]; | |
| 277 outptr[RGB_GREEN] = range_limit[y + cgreen]; | |
| 278 outptr[RGB_BLUE] = range_limit[y + cblue]; | |
| 279 } | |
| 280 } | |
| 281 | |
| 282 | |
| 283 /* | |
| 284 * Upsample and color convert for the case of 2:1 horizontal and 2:1 vertical. | |
| 285 */ | |
| 286 | |
| 287 METHODDEF(void) | |
| 288 h2v2_merged_upsample (j_decompress_ptr cinfo, | |
| 289 JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr, | |
| 290 JSAMPARRAY output_buf) | |
| 291 { | |
| 292 my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample; | |
| 293 register int y, cred, cgreen, cblue; | |
| 294 int cb, cr; | |
| 295 register JSAMPROW outptr0, outptr1; | |
| 296 JSAMPROW inptr00, inptr01, inptr1, inptr2; | |
| 297 JDIMENSION col; | |
| 298 /* copy these pointers into registers if possible */ | |
| 299 register JSAMPLE * range_limit = cinfo->sample_range_limit; | |
| 300 int * Crrtab = upsample->Cr_r_tab; | |
| 301 int * Cbbtab = upsample->Cb_b_tab; | |
| 302 INT32 * Crgtab = upsample->Cr_g_tab; | |
| 303 INT32 * Cbgtab = upsample->Cb_g_tab; | |
| 304 SHIFT_TEMPS | |
| 305 | |
| 306 inptr00 = input_buf[0][in_row_group_ctr*2]; | |
| 307 inptr01 = input_buf[0][in_row_group_ctr*2 + 1]; | |
| 308 inptr1 = input_buf[1][in_row_group_ctr]; | |
| 309 inptr2 = input_buf[2][in_row_group_ctr]; | |
| 310 outptr0 = output_buf[0]; | |
| 311 outptr1 = output_buf[1]; | |
| 312 /* Loop for each group of output pixels */ | |
| 313 for (col = cinfo->output_width >> 1; col > 0; col--) { | |
| 314 /* Do the chroma part of the calculation */ | |
| 315 cb = GETJSAMPLE(*inptr1++); | |
| 316 cr = GETJSAMPLE(*inptr2++); | |
| 317 cred = Crrtab[cr]; | |
| 318 cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS); | |
| 319 cblue = Cbbtab[cb]; | |
| 320 /* Fetch 4 Y values and emit 4 pixels */ | |
| 321 y = GETJSAMPLE(*inptr00++); | |
| 322 outptr0[RGB_RED] = range_limit[y + cred]; | |
| 323 outptr0[RGB_GREEN] = range_limit[y + cgreen]; | |
| 324 outptr0[RGB_BLUE] = range_limit[y + cblue]; | |
| 325 outptr0 += RGB_PIXELSIZE; | |
| 326 y = GETJSAMPLE(*inptr00++); | |
| 327 outptr0[RGB_RED] = range_limit[y + cred]; | |
| 328 outptr0[RGB_GREEN] = range_limit[y + cgreen]; | |
| 329 outptr0[RGB_BLUE] = range_limit[y + cblue]; | |
| 330 outptr0 += RGB_PIXELSIZE; | |
| 331 y = GETJSAMPLE(*inptr01++); | |
| 332 outptr1[RGB_RED] = range_limit[y + cred]; | |
| 333 outptr1[RGB_GREEN] = range_limit[y + cgreen]; | |
| 334 outptr1[RGB_BLUE] = range_limit[y + cblue]; | |
| 335 outptr1 += RGB_PIXELSIZE; | |
| 336 y = GETJSAMPLE(*inptr01++); | |
| 337 outptr1[RGB_RED] = range_limit[y + cred]; | |
| 338 outptr1[RGB_GREEN] = range_limit[y + cgreen]; | |
| 339 outptr1[RGB_BLUE] = range_limit[y + cblue]; | |
| 340 outptr1 += RGB_PIXELSIZE; | |
| 341 } | |
| 342 /* If image width is odd, do the last output column separately */ | |
| 343 if (cinfo->output_width & 1) { | |
| 344 cb = GETJSAMPLE(*inptr1); | |
| 345 cr = GETJSAMPLE(*inptr2); | |
| 346 cred = Crrtab[cr]; | |
| 347 cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS); | |
| 348 cblue = Cbbtab[cb]; | |
| 349 y = GETJSAMPLE(*inptr00); | |
| 350 outptr0[RGB_RED] = range_limit[y + cred]; | |
| 351 outptr0[RGB_GREEN] = range_limit[y + cgreen]; | |
| 352 outptr0[RGB_BLUE] = range_limit[y + cblue]; | |
| 353 y = GETJSAMPLE(*inptr01); | |
| 354 outptr1[RGB_RED] = range_limit[y + cred]; | |
| 355 outptr1[RGB_GREEN] = range_limit[y + cgreen]; | |
| 356 outptr1[RGB_BLUE] = range_limit[y + cblue]; | |
| 357 } | |
| 358 } | |
| 359 | |
| 360 | |
| 361 /* | |
| 362 * Module initialization routine for merged upsampling/color conversion. | |
| 363 * | |
| 364 * NB: this is called under the conditions determined by use_merged_upsample() | |
| 365 * in jdmaster.c. That routine MUST correspond to the actual capabilities | |
| 366 * of this module; no safety checks are made here. | |
| 367 */ | |
| 368 | |
| 369 GLOBAL(void) | |
| 370 jinit_merged_upsampler (j_decompress_ptr cinfo) | |
| 371 { | |
| 372 my_upsample_ptr upsample; | |
| 373 | |
| 374 upsample = (my_upsample_ptr) | |
| 375 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 376 SIZEOF(my_upsampler)); | |
| 377 cinfo->upsample = (struct jpeg_upsampler *) upsample; | |
| 378 upsample->pub.start_pass = start_pass_merged_upsample; | |
| 379 upsample->pub.need_context_rows = FALSE; | |
| 380 | |
| 381 upsample->out_row_width = cinfo->output_width * cinfo->out_color_components; | |
| 382 | |
| 383 if (cinfo->max_v_samp_factor == 2) { | |
| 384 upsample->pub.upsample = merged_2v_upsample; | |
| 385 upsample->upmethod = h2v2_merged_upsample; | |
| 386 /* Allocate a spare row buffer */ | |
| 387 upsample->spare_row = (JSAMPROW) | |
| 388 (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 389 (size_t) (upsample->out_row_width * SIZEOF(JSAMPLE))); | |
| 390 } else { | |
| 391 upsample->pub.upsample = merged_1v_upsample; | |
| 392 upsample->upmethod = h2v1_merged_upsample; | |
| 393 /* No spare row needed */ | |
| 394 upsample->spare_row = NULL; | |
| 395 } | |
| 396 | |
| 397 build_ycc_rgb_table(cinfo); | |
| 398 } | |
| 399 | |
| 400 #endif /* UPSAMPLE_MERGING_SUPPORTED */ | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 1705523002:
Remove libjpeg and libjpeg_turbo. (Closed)
Base URL: https://github.com/domokit/mojo.git@master