media/libjpeg/jccolor.c

   1 /*
   2  * jccolor.c
   3  *
   4  * This file was part of the Independent JPEG Group's software:
   5  * Copyright (C) 1991-1996, Thomas G. Lane.
   6  * libjpeg-turbo Modifications:
   7  * Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
   8  * Copyright (C) 2009-2012, 2015, 2022, D. R. Commander.
   9  * Copyright (C) 2014, MIPS Technologies, Inc., California.
  10  * For conditions of distribution and use, see the accompanying README.ijg
  11  * file.
  12  *
  13  * This file contains input colorspace conversion routines.
  14  */
  15
  16 #define JPEG_INTERNALS
  17 #include "jinclude.h"
  18 #include "jpeglib.h"
  19 #include "jsimd.h"
  20 #include "jsamplecomp.h"
  21
  22
  23 #if BITS_IN_JSAMPLE != 16 || defined(C_LOSSLESS_SUPPORTED)
  24
  25 /* Private subobject */
  26
  27 typedef struct {
  28   struct jpeg_color_converter pub; /* public fields */
  29
  30 #if BITS_IN_JSAMPLE != 16
  31   /* Private state for RGB->YCC conversion */
  32   JLONG *rgb_ycc_tab;           /* => table for RGB to YCbCr conversion */
  33 #endif
  34 } my_color_converter;
  35
  36 typedef my_color_converter *my_cconvert_ptr;
  37
  38
  39 /**************** RGB -> YCbCr conversion: most common case **************/
  40
  41 /*
  42  * YCbCr is defined per CCIR 601-1, except that Cb and Cr are
  43  * normalized to the range 0.._MAXJSAMPLE rather than -0.5 .. 0.5.
  44  * The conversion equations to be implemented are therefore
  45  *      Y  =  0.29900 * R + 0.58700 * G + 0.11400 * B
  46  *      Cb = -0.16874 * R - 0.33126 * G + 0.50000 * B  + _CENTERJSAMPLE
  47  *      Cr =  0.50000 * R - 0.41869 * G - 0.08131 * B  + _CENTERJSAMPLE
  48  * (These numbers are derived from TIFF 6.0 section 21, dated 3-June-92.)
  49  * Note: older versions of the IJG code used a zero offset of _MAXJSAMPLE/2,
  50  * rather than _CENTERJSAMPLE, for Cb and Cr.  This gave equal positive and
  51  * negative swings for Cb/Cr, but meant that grayscale values (Cb=Cr=0)
  52  * were not represented exactly.  Now we sacrifice exact representation of
  53  * maximum red and maximum blue in order to get exact grayscales.
  54  *
  55  * To avoid floating-point arithmetic, we represent the fractional constants
  56  * as integers scaled up by 2^16 (about 4 digits precision); we have to divide
  57  * the products by 2^16, with appropriate rounding, to get the correct answer.
  58  *
  59  * For even more speed, we avoid doing any multiplications in the inner loop
  60  * by precalculating the constants times R,G,B for all possible values.
  61  * For 8-bit samples this is very reasonable (only 256 entries per table);
  62  * for 12-bit samples it is still acceptable.  It's not very reasonable for
  63  * 16-bit samples, but if you want lossless storage you shouldn't be changing
  64  * colorspace anyway.
  65  * The _CENTERJSAMPLE offsets and the rounding fudge-factor of 0.5 are included
  66  * in the tables to save adding them separately in the inner loop.
  67  */
  68
  69 #define SCALEBITS       16      /* speediest right-shift on some machines */
  70 #define CBCR_OFFSET     ((JLONG)_CENTERJSAMPLE << SCALEBITS)
  71 #define ONE_HALF        ((JLONG)1 << (SCALEBITS - 1))
  72 #define FIX(x)          ((JLONG)((x) * (1L << SCALEBITS) + 0.5))
  73
  74 /* We allocate one big table and divide it up into eight parts, instead of
  75  * doing eight alloc_small requests.  This lets us use a single table base
  76  * address, which can be held in a register in the inner loops on many
  77  * machines (more than can hold all eight addresses, anyway).
  78  */
  79
  80 #define R_Y_OFF         0                       /* offset to R => Y section */
  81 #define G_Y_OFF         (1 * (_MAXJSAMPLE + 1)) /* offset to G => Y section */
  82 #define B_Y_OFF         (2 * (_MAXJSAMPLE + 1)) /* etc. */
  83 #define R_CB_OFF        (3 * (_MAXJSAMPLE + 1))
  84 #define G_CB_OFF        (4 * (_MAXJSAMPLE + 1))
  85 #define B_CB_OFF        (5 * (_MAXJSAMPLE + 1))
  86 #define R_CR_OFF        B_CB_OFF                /* B=>Cb, R=>Cr are the same */
  87 #define G_CR_OFF        (6 * (_MAXJSAMPLE + 1))
  88 #define B_CR_OFF        (7 * (_MAXJSAMPLE + 1))
  89 #define TABLE_SIZE      (8 * (_MAXJSAMPLE + 1))
  90
  91 /* 12-bit samples use a 16-bit data type, so it is possible to pass
  92  * out-of-range sample values (< 0 or > 4095) to jpeg_write_scanlines().
  93  * Thus, we mask the incoming 12-bit samples to guard against overrunning
  94  * or underrunning the conversion tables.
  95  */
  96
  97 #if BITS_IN_JSAMPLE == 12
  98 #define RANGE_LIMIT(value)  ((value) & 0xFFF)
  99 #else
 100 #define RANGE_LIMIT(value)  (value)
 101 #endif
 102
 103
 104 /* Include inline routines for colorspace extensions */
 105
 106 #include "jccolext.c"
 107 #undef RGB_RED
 108 #undef RGB_GREEN
 109 #undef RGB_BLUE
 110 #undef RGB_PIXELSIZE
 111
 112 #define RGB_RED  EXT_RGB_RED
 113 #define RGB_GREEN  EXT_RGB_GREEN
 114 #define RGB_BLUE  EXT_RGB_BLUE
 115 #define RGB_PIXELSIZE  EXT_RGB_PIXELSIZE
 116 #define rgb_ycc_convert_internal  extrgb_ycc_convert_internal
 117 #define rgb_gray_convert_internal  extrgb_gray_convert_internal
 118 #define rgb_rgb_convert_internal  extrgb_rgb_convert_internal
 119 #include "jccolext.c"
 120 #undef RGB_RED
 121 #undef RGB_GREEN
 122 #undef RGB_BLUE
 123 #undef RGB_PIXELSIZE
 124 #undef rgb_ycc_convert_internal
 125 #undef rgb_gray_convert_internal
 126 #undef rgb_rgb_convert_internal
 127
 128 #define RGB_RED  EXT_RGBX_RED
 129 #define RGB_GREEN  EXT_RGBX_GREEN
 130 #define RGB_BLUE  EXT_RGBX_BLUE
 131 #define RGB_PIXELSIZE  EXT_RGBX_PIXELSIZE
 132 #define rgb_ycc_convert_internal  extrgbx_ycc_convert_internal
 133 #define rgb_gray_convert_internal  extrgbx_gray_convert_internal
 134 #define rgb_rgb_convert_internal  extrgbx_rgb_convert_internal
 135 #include "jccolext.c"
 136 #undef RGB_RED
 137 #undef RGB_GREEN
 138 #undef RGB_BLUE
 139 #undef RGB_PIXELSIZE
 140 #undef rgb_ycc_convert_internal
 141 #undef rgb_gray_convert_internal
 142 #undef rgb_rgb_convert_internal
 143
 144 #define RGB_RED  EXT_BGR_RED
 145 #define RGB_GREEN  EXT_BGR_GREEN
 146 #define RGB_BLUE  EXT_BGR_BLUE
 147 #define RGB_PIXELSIZE  EXT_BGR_PIXELSIZE
 148 #define rgb_ycc_convert_internal  extbgr_ycc_convert_internal
 149 #define rgb_gray_convert_internal  extbgr_gray_convert_internal
 150 #define rgb_rgb_convert_internal  extbgr_rgb_convert_internal
 151 #include "jccolext.c"
 152 #undef RGB_RED
 153 #undef RGB_GREEN
 154 #undef RGB_BLUE
 155 #undef RGB_PIXELSIZE
 156 #undef rgb_ycc_convert_internal
 157 #undef rgb_gray_convert_internal
 158 #undef rgb_rgb_convert_internal
 159
 160 #define RGB_RED  EXT_BGRX_RED
 161 #define RGB_GREEN  EXT_BGRX_GREEN
 162 #define RGB_BLUE  EXT_BGRX_BLUE
 163 #define RGB_PIXELSIZE  EXT_BGRX_PIXELSIZE
 164 #define rgb_ycc_convert_internal  extbgrx_ycc_convert_internal
 165 #define rgb_gray_convert_internal  extbgrx_gray_convert_internal
 166 #define rgb_rgb_convert_internal  extbgrx_rgb_convert_internal
 167 #include "jccolext.c"
 168 #undef RGB_RED
 169 #undef RGB_GREEN
 170 #undef RGB_BLUE
 171 #undef RGB_PIXELSIZE
 172 #undef rgb_ycc_convert_internal
 173 #undef rgb_gray_convert_internal
 174 #undef rgb_rgb_convert_internal
 175
 176 #define RGB_RED  EXT_XBGR_RED
 177 #define RGB_GREEN  EXT_XBGR_GREEN
 178 #define RGB_BLUE  EXT_XBGR_BLUE
 179 #define RGB_PIXELSIZE  EXT_XBGR_PIXELSIZE
 180 #define rgb_ycc_convert_internal  extxbgr_ycc_convert_internal
 181 #define rgb_gray_convert_internal  extxbgr_gray_convert_internal
 182 #define rgb_rgb_convert_internal  extxbgr_rgb_convert_internal
 183 #include "jccolext.c"
 184 #undef RGB_RED
 185 #undef RGB_GREEN
 186 #undef RGB_BLUE
 187 #undef RGB_PIXELSIZE
 188 #undef rgb_ycc_convert_internal
 189 #undef rgb_gray_convert_internal
 190 #undef rgb_rgb_convert_internal
 191
 192 #define RGB_RED  EXT_XRGB_RED
 193 #define RGB_GREEN  EXT_XRGB_GREEN
 194 #define RGB_BLUE  EXT_XRGB_BLUE
 195 #define RGB_PIXELSIZE  EXT_XRGB_PIXELSIZE
 196 #define rgb_ycc_convert_internal  extxrgb_ycc_convert_internal
 197 #define rgb_gray_convert_internal  extxrgb_gray_convert_internal
 198 #define rgb_rgb_convert_internal  extxrgb_rgb_convert_internal
 199 #include "jccolext.c"
 200 #undef RGB_RED
 201 #undef RGB_GREEN
 202 #undef RGB_BLUE
 203 #undef RGB_PIXELSIZE
 204 #undef rgb_ycc_convert_internal
 205 #undef rgb_gray_convert_internal
 206 #undef rgb_rgb_convert_internal
 207
 208
 209 /*
 210  * Initialize for RGB->YCC colorspace conversion.
 211  */
 212
 213 METHODDEF(void)
 214 rgb_ycc_start(j_compress_ptr cinfo)
 215 {
 216 #if BITS_IN_JSAMPLE != 16
 217   my_cconvert_ptr cconvert = (my_cconvert_ptr)cinfo->cconvert;
 218   JLONG *rgb_ycc_tab;
 219   JLONG i;
 220
 221   /* Allocate and fill in the conversion tables. */
 222   cconvert->rgb_ycc_tab = rgb_ycc_tab = (JLONG *)
 223     (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
 224                                 (TABLE_SIZE * sizeof(JLONG)));
 225
 226   for (i = 0; i <= _MAXJSAMPLE; i++) {
 227     rgb_ycc_tab[i + R_Y_OFF] = FIX(0.29900) * i;
 228     rgb_ycc_tab[i + G_Y_OFF] = FIX(0.58700) * i;
 229     rgb_ycc_tab[i + B_Y_OFF] = FIX(0.11400) * i   + ONE_HALF;
 230     rgb_ycc_tab[i + R_CB_OFF] = (-FIX(0.16874)) * i;
 231     rgb_ycc_tab[i + G_CB_OFF] = (-FIX(0.33126)) * i;
 232     /* We use a rounding fudge-factor of 0.5-epsilon for Cb and Cr.
 233      * This ensures that the maximum output will round to _MAXJSAMPLE
 234      * not _MAXJSAMPLE+1, and thus that we don't have to range-limit.
 235      */
 236     rgb_ycc_tab[i + B_CB_OFF] = FIX(0.50000) * i  + CBCR_OFFSET + ONE_HALF - 1;
 237 /*  B=>Cb and R=>Cr tables are the same
 238     rgb_ycc_tab[i + R_CR_OFF] = FIX(0.50000) * i  + CBCR_OFFSET + ONE_HALF - 1;
 239 */
 240     rgb_ycc_tab[i + G_CR_OFF] = (-FIX(0.41869)) * i;
 241     rgb_ycc_tab[i + B_CR_OFF] = (-FIX(0.08131)) * i;
 242   }
 243 #else
 244   ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
 245 #endif
 246 }
 247
 248
 249 /*
 250  * Convert some rows of samples to the JPEG colorspace.
 251  */
 252
 253 METHODDEF(void)
 254 rgb_ycc_convert(j_compress_ptr cinfo, _JSAMPARRAY input_buf,
 255                 _JSAMPIMAGE output_buf, JDIMENSION output_row, int num_rows)
 256 {
 257   switch (cinfo->in_color_space) {
 258   case JCS_EXT_RGB:
 259     extrgb_ycc_convert_internal(cinfo, input_buf, output_buf, output_row,
 260                                 num_rows);
 261     break;
 262   case JCS_EXT_RGBX:
 263   case JCS_EXT_RGBA:
 264     extrgbx_ycc_convert_internal(cinfo, input_buf, output_buf, output_row,
 265                                  num_rows);
 266     break;
 267   case JCS_EXT_BGR:
 268     extbgr_ycc_convert_internal(cinfo, input_buf, output_buf, output_row,
 269                                 num_rows);
 270     break;
 271   case JCS_EXT_BGRX:
 272   case JCS_EXT_BGRA:
 273     extbgrx_ycc_convert_internal(cinfo, input_buf, output_buf, output_row,
 274                                  num_rows);
 275     break;
 276   case JCS_EXT_XBGR:
 277   case JCS_EXT_ABGR:
 278     extxbgr_ycc_convert_internal(cinfo, input_buf, output_buf, output_row,
 279                                  num_rows);
 280     break;
 281   case JCS_EXT_XRGB:
 282   case JCS_EXT_ARGB:
 283     extxrgb_ycc_convert_internal(cinfo, input_buf, output_buf, output_row,
 284                                  num_rows);
 285     break;
 286   default:
 287     rgb_ycc_convert_internal(cinfo, input_buf, output_buf, output_row,
 288                              num_rows);
 289     break;
 290   }
 291 }
 292
 293
 294 /**************** Cases other than RGB -> YCbCr **************/
 295
 296
 297 /*
 298  * Convert some rows of samples to the JPEG colorspace.
 299  */
 300
 301 METHODDEF(void)
 302 rgb_gray_convert(j_compress_ptr cinfo, _JSAMPARRAY input_buf,
 303                  _JSAMPIMAGE output_buf, JDIMENSION output_row, int num_rows)
 304 {
 305   switch (cinfo->in_color_space) {
 306   case JCS_EXT_RGB:
 307     extrgb_gray_convert_internal(cinfo, input_buf, output_buf, output_row,
 308                                  num_rows);
 309     break;
 310   case JCS_EXT_RGBX:
 311   case JCS_EXT_RGBA:
 312     extrgbx_gray_convert_internal(cinfo, input_buf, output_buf, output_row,
 313                                   num_rows);
 314     break;
 315   case JCS_EXT_BGR:
 316     extbgr_gray_convert_internal(cinfo, input_buf, output_buf, output_row,
 317                                  num_rows);
 318     break;
 319   case JCS_EXT_BGRX:
 320   case JCS_EXT_BGRA:
 321     extbgrx_gray_convert_internal(cinfo, input_buf, output_buf, output_row,
 322                                   num_rows);
 323     break;
 324   case JCS_EXT_XBGR:
 325   case JCS_EXT_ABGR:
 326     extxbgr_gray_convert_internal(cinfo, input_buf, output_buf, output_row,
 327                                   num_rows);
 328     break;
 329   case JCS_EXT_XRGB:
 330   case JCS_EXT_ARGB:
 331     extxrgb_gray_convert_internal(cinfo, input_buf, output_buf, output_row,
 332                                   num_rows);
 333     break;
 334   default:
 335     rgb_gray_convert_internal(cinfo, input_buf, output_buf, output_row,
 336                               num_rows);
 337     break;
 338   }
 339 }
 340
 341
 342 /*
 343  * Extended RGB to plain RGB conversion
 344  */
 345
 346 METHODDEF(void)
 347 rgb_rgb_convert(j_compress_ptr cinfo, _JSAMPARRAY input_buf,
 348                 _JSAMPIMAGE output_buf, JDIMENSION output_row, int num_rows)
 349 {
 350   switch (cinfo->in_color_space) {
 351   case JCS_EXT_RGB:
 352     extrgb_rgb_convert_internal(cinfo, input_buf, output_buf, output_row,
 353                                 num_rows);
 354     break;
 355   case JCS_EXT_RGBX:
 356   case JCS_EXT_RGBA:
 357     extrgbx_rgb_convert_internal(cinfo, input_buf, output_buf, output_row,
 358                                  num_rows);
 359     break;
 360   case JCS_EXT_BGR:
 361     extbgr_rgb_convert_internal(cinfo, input_buf, output_buf, output_row,
 362                                 num_rows);
 363     break;
 364   case JCS_EXT_BGRX:
 365   case JCS_EXT_BGRA:
 366     extbgrx_rgb_convert_internal(cinfo, input_buf, output_buf, output_row,
 367                                  num_rows);
 368     break;
 369   case JCS_EXT_XBGR:
 370   case JCS_EXT_ABGR:
 371     extxbgr_rgb_convert_internal(cinfo, input_buf, output_buf, output_row,
 372                                  num_rows);
 373     break;
 374   case JCS_EXT_XRGB:
 375   case JCS_EXT_ARGB:
 376     extxrgb_rgb_convert_internal(cinfo, input_buf, output_buf, output_row,
 377                                  num_rows);
 378     break;
 379   default:
 380     rgb_rgb_convert_internal(cinfo, input_buf, output_buf, output_row,
 381                              num_rows);
 382     break;
 383   }
 384 }
 385
 386
 387 /*
 388  * Convert some rows of samples to the JPEG colorspace.
 389  * This version handles Adobe-style CMYK->YCCK conversion,
 390  * where we convert R=1-C, G=1-M, and B=1-Y to YCbCr using the same
 391  * conversion as above, while passing K (black) unchanged.
 392  * We assume rgb_ycc_start has been called.
 393  */
 394
 395 METHODDEF(void)
 396 cmyk_ycck_convert(j_compress_ptr cinfo, _JSAMPARRAY input_buf,
 397                   _JSAMPIMAGE output_buf, JDIMENSION output_row, int num_rows)
 398 {
 399 #if BITS_IN_JSAMPLE != 16
 400   my_cconvert_ptr cconvert = (my_cconvert_ptr)cinfo->cconvert;
 401   register int r, g, b;
 402   register JLONG *ctab = cconvert->rgb_ycc_tab;
 403   register _JSAMPROW inptr;
 404   register _JSAMPROW outptr0, outptr1, outptr2, outptr3;
 405   register JDIMENSION col;
 406   JDIMENSION num_cols = cinfo->image_width;
 407
 408   while (--num_rows >= 0) {
 409     inptr = *input_buf++;
 410     outptr0 = output_buf[0][output_row];
 411     outptr1 = output_buf[1][output_row];
 412     outptr2 = output_buf[2][output_row];
 413     outptr3 = output_buf[3][output_row];
 414     output_row++;
 415     for (col = 0; col < num_cols; col++) {
 416       r = _MAXJSAMPLE - RANGE_LIMIT(inptr[0]);
 417       g = _MAXJSAMPLE - RANGE_LIMIT(inptr[1]);
 418       b = _MAXJSAMPLE - RANGE_LIMIT(inptr[2]);
 419       /* K passes through as-is */
 420       outptr3[col] = inptr[3];
 421       inptr += 4;
 422       /* If the inputs are 0.._MAXJSAMPLE, the outputs of these equations
 423        * must be too; we do not need an explicit range-limiting operation.
 424        * Hence the value being shifted is never negative, and we don't
 425        * need the general RIGHT_SHIFT macro.
 426        */
 427       /* Y */
 428       outptr0[col] = (_JSAMPLE)((ctab[r + R_Y_OFF] + ctab[g + G_Y_OFF] +
 429                                  ctab[b + B_Y_OFF]) >> SCALEBITS);
 430       /* Cb */
 431       outptr1[col] = (_JSAMPLE)((ctab[r + R_CB_OFF] + ctab[g + G_CB_OFF] +
 432                                  ctab[b + B_CB_OFF]) >> SCALEBITS);
 433       /* Cr */
 434       outptr2[col] = (_JSAMPLE)((ctab[r + R_CR_OFF] + ctab[g + G_CR_OFF] +
 435                                  ctab[b + B_CR_OFF]) >> SCALEBITS);
 436     }
 437   }
 438 #else
 439   ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
 440 #endif
 441 }
 442
 443
 444 /*
 445  * Convert some rows of samples to the JPEG colorspace.
 446  * This version handles grayscale output with no conversion.
 447  * The source can be either plain grayscale or YCbCr (since Y == gray).
 448  */
 449
 450 METHODDEF(void)
 451 grayscale_convert(j_compress_ptr cinfo, _JSAMPARRAY input_buf,
 452                   _JSAMPIMAGE output_buf, JDIMENSION output_row, int num_rows)
 453 {
 454   register _JSAMPROW inptr;
 455   register _JSAMPROW outptr;
 456   register JDIMENSION col;
 457   JDIMENSION num_cols = cinfo->image_width;
 458   int instride = cinfo->input_components;
 459
 460   while (--num_rows >= 0) {
 461     inptr = *input_buf++;
 462     outptr = output_buf[0][output_row];
 463     output_row++;
 464     for (col = 0; col < num_cols; col++) {
 465       outptr[col] = inptr[0];
 466       inptr += instride;
 467     }
 468   }
 469 }
 470
 471
 472 /*
 473  * Convert some rows of samples to the JPEG colorspace.
 474  * This version handles multi-component colorspaces without conversion.
 475  * We assume input_components == num_components.
 476  */
 477
 478 METHODDEF(void)
 479 null_convert(j_compress_ptr cinfo, _JSAMPARRAY input_buf,
 480              _JSAMPIMAGE output_buf, JDIMENSION output_row, int num_rows)
 481 {
 482   register _JSAMPROW inptr;
 483   register _JSAMPROW outptr, outptr0, outptr1, outptr2, outptr3;
 484   register JDIMENSION col;
 485   register int ci;
 486   int nc = cinfo->num_components;
 487   JDIMENSION num_cols = cinfo->image_width;
 488
 489   if (nc == 3) {
 490     while (--num_rows >= 0) {
 491       inptr = *input_buf++;
 492       outptr0 = output_buf[0][output_row];
 493       outptr1 = output_buf[1][output_row];
 494       outptr2 = output_buf[2][output_row];
 495       output_row++;
 496       for (col = 0; col < num_cols; col++) {
 497         outptr0[col] = *inptr++;
 498         outptr1[col] = *inptr++;
 499         outptr2[col] = *inptr++;
 500       }
 501     }
 502   } else if (nc == 4) {
 503     while (--num_rows >= 0) {
 504       inptr = *input_buf++;
 505       outptr0 = output_buf[0][output_row];
 506       outptr1 = output_buf[1][output_row];
 507       outptr2 = output_buf[2][output_row];
 508       outptr3 = output_buf[3][output_row];
 509       output_row++;
 510       for (col = 0; col < num_cols; col++) {
 511         outptr0[col] = *inptr++;
 512         outptr1[col] = *inptr++;
 513         outptr2[col] = *inptr++;
 514         outptr3[col] = *inptr++;
 515       }
 516     }
 517   } else {
 518     while (--num_rows >= 0) {
 519       /* It seems fastest to make a separate pass for each component. */
 520       for (ci = 0; ci < nc; ci++) {
 521         inptr = *input_buf;
 522         outptr = output_buf[ci][output_row];
 523         for (col = 0; col < num_cols; col++) {
 524           outptr[col] = inptr[ci];
 525           inptr += nc;
 526         }
 527       }
 528       input_buf++;
 529       output_row++;
 530     }
 531   }
 532 }
 533
 534
 535 /*
 536  * Empty method for start_pass.
 537  */
 538
 539 METHODDEF(void)
 540 null_method(j_compress_ptr cinfo)
 541 {
 542   /* no work needed */
 543 }
 544
 545
 546 /*
 547  * Module initialization routine for input colorspace conversion.
 548  */
 549
 550 GLOBAL(void)
 551 _jinit_color_converter(j_compress_ptr cinfo)
 552 {
 553   my_cconvert_ptr cconvert;
 554
 555   if (cinfo->data_precision != BITS_IN_JSAMPLE)
 556     ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
 557
 558   cconvert = (my_cconvert_ptr)
 559     (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
 560                                 sizeof(my_color_converter));
 561   cinfo->cconvert = (struct jpeg_color_converter *)cconvert;
 562   /* set start_pass to null method until we find out differently */
 563   cconvert->pub.start_pass = null_method;
 564
 565   /* Make sure input_components agrees with in_color_space */
 566   switch (cinfo->in_color_space) {
 567   case JCS_GRAYSCALE:
 568     if (cinfo->input_components != 1)
 569       ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
 570     break;
 571
 572   case JCS_RGB:
 573   case JCS_EXT_RGB:
 574   case JCS_EXT_RGBX:
 575   case JCS_EXT_BGR:
 576   case JCS_EXT_BGRX:
 577   case JCS_EXT_XBGR:
 578   case JCS_EXT_XRGB:
 579   case JCS_EXT_RGBA:
 580   case JCS_EXT_BGRA:
 581   case JCS_EXT_ABGR:
 582   case JCS_EXT_ARGB:
 583     if (cinfo->input_components != rgb_pixelsize[cinfo->in_color_space])
 584       ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
 585     break;
 586
 587   case JCS_YCbCr:
 588     if (cinfo->input_components != 3)
 589       ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
 590     break;
 591
 592   case JCS_CMYK:
 593   case JCS_YCCK:
 594     if (cinfo->input_components != 4)
 595       ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
 596     break;
 597
 598   default:                      /* JCS_UNKNOWN can be anything */
 599     if (cinfo->input_components < 1)
 600       ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
 601     break;
 602   }
 603
 604   /* Check num_components, set conversion method based on requested space.
 605    * NOTE: We do not allow any lossy color conversion algorithms in lossless
 606    * mode.
 607    */
 608   switch (cinfo->jpeg_color_space) {
 609   case JCS_GRAYSCALE:
 610     if (cinfo->master->lossless &&
 611         cinfo->in_color_space != cinfo->jpeg_color_space)
 612       ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
 613     if (cinfo->num_components != 1)
 614       ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
 615     if (cinfo->in_color_space == JCS_GRAYSCALE)
 616       cconvert->pub._color_convert = grayscale_convert;
 617     else if (IsExtRGB(cinfo->in_color_space)) {
 618 #ifdef WITH_SIMD
 619       if (jsimd_can_rgb_gray())
 620         cconvert->pub._color_convert = jsimd_rgb_gray_convert;
 621       else
 622 #endif
 623       {
 624         cconvert->pub.start_pass = rgb_ycc_start;
 625         cconvert->pub._color_convert = rgb_gray_convert;
 626       }
 627     } else if (cinfo->in_color_space == JCS_YCbCr)
 628       cconvert->pub._color_convert = grayscale_convert;
 629     else
 630       ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
 631     break;
 632
 633   case JCS_RGB:
 634     if (cinfo->master->lossless && !IsExtRGB(cinfo->in_color_space))
 635       ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
 636     if (cinfo->num_components != 3)
 637       ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
 638     if (rgb_red[cinfo->in_color_space] == 0 &&
 639         rgb_green[cinfo->in_color_space] == 1 &&
 640         rgb_blue[cinfo->in_color_space] == 2 &&
 641         rgb_pixelsize[cinfo->in_color_space] == 3) {
 642 #if defined(WITH_SIMD) && defined(__mips__)
 643       if (jsimd_c_can_null_convert())
 644         cconvert->pub._color_convert = jsimd_c_null_convert;
 645       else
 646 #endif
 647         cconvert->pub._color_convert = null_convert;
 648     } else if (IsExtRGB(cinfo->in_color_space))
 649       cconvert->pub._color_convert = rgb_rgb_convert;
 650     else
 651       ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
 652     break;
 653
 654   case JCS_YCbCr:
 655     if (cinfo->master->lossless &&
 656         cinfo->in_color_space != cinfo->jpeg_color_space)
 657       ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
 658     if (cinfo->num_components != 3)
 659       ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
 660     if (IsExtRGB(cinfo->in_color_space)) {
 661 #ifdef WITH_SIMD
 662       if (jsimd_can_rgb_ycc())
 663         cconvert->pub._color_convert = jsimd_rgb_ycc_convert;
 664       else
 665 #endif
 666       {
 667         cconvert->pub.start_pass = rgb_ycc_start;
 668         cconvert->pub._color_convert = rgb_ycc_convert;
 669       }
 670     } else if (cinfo->in_color_space == JCS_YCbCr) {
 671 #if defined(WITH_SIMD) && defined(__mips__)
 672       if (jsimd_c_can_null_convert())
 673         cconvert->pub._color_convert = jsimd_c_null_convert;
 674       else
 675 #endif
 676         cconvert->pub._color_convert = null_convert;
 677     } else
 678       ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
 679     break;
 680
 681   case JCS_CMYK:
 682     if (cinfo->master->lossless &&
 683         cinfo->in_color_space != cinfo->jpeg_color_space)
 684       ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
 685     if (cinfo->num_components != 4)
 686       ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
 687     if (cinfo->in_color_space == JCS_CMYK) {
 688 #if defined(WITH_SIMD) && defined(__mips__)
 689       if (jsimd_c_can_null_convert())
 690         cconvert->pub._color_convert = jsimd_c_null_convert;
 691       else
 692 #endif
 693         cconvert->pub._color_convert = null_convert;
 694     } else
 695       ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
 696     break;
 697
 698   case JCS_YCCK:
 699     if (cinfo->master->lossless &&
 700         cinfo->in_color_space != cinfo->jpeg_color_space)
 701       ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
 702     if (cinfo->num_components != 4)
 703       ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
 704     if (cinfo->in_color_space == JCS_CMYK) {
 705       cconvert->pub.start_pass = rgb_ycc_start;
 706       cconvert->pub._color_convert = cmyk_ycck_convert;
 707     } else if (cinfo->in_color_space == JCS_YCCK) {
 708 #if defined(WITH_SIMD) && defined(__mips__)
 709       if (jsimd_c_can_null_convert())
 710         cconvert->pub._color_convert = jsimd_c_null_convert;
 711       else
 712 #endif
 713         cconvert->pub._color_convert = null_convert;
 714     } else
 715       ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
 716     break;
 717
 718   default:                      /* allow null conversion of JCS_UNKNOWN */
 719     if (cinfo->jpeg_color_space != cinfo->in_color_space ||
 720         cinfo->num_components != cinfo->input_components)
 721       ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
 722 #if defined(WITH_SIMD) && defined(__mips__)
 723     if (jsimd_c_can_null_convert())
 724       cconvert->pub._color_convert = jsimd_c_null_convert;
 725     else
 726 #endif
 727       cconvert->pub._color_convert = null_convert;
 728     break;
 729   }
 730 }
 731
 732 #endif /* BITS_IN_JSAMPLE != 16 || defined(C_LOSSLESS_SUPPORTED) */