com32/lib/jpeg/bgra32.c

   1 /*
   2  * Small jpeg decoder library
   3  *
   4  * Copyright (c) 2006, Luc Saillard <luc@saillard.org>
   5  * All rights reserved.
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright notice,
  10  *  this list of conditions and the following disclaimer.
  11  *
  12  * - Redistributions in binary form must reproduce the above copyright notice,
  13  *  this list of conditions and the following disclaimer in the documentation
  14  *  and/or other materials provided with the distribution.
  15  *
  16  * - Neither the name of the author nor the names of its contributors may be
  17  *  used to endorse or promote products derived from this software without
  18  *  specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  21  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  24  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  30  * POSSIBILITY OF SUCH DAMAGE.
  31  *
  32  */
  33
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <stdint.h>
  38
  39 #include "tinyjpeg.h"
  40 #include "tinyjpeg-internal.h"
  41
  42 /*******************************************************************************
  43  *
  44  * Colorspace conversion routine
  45  *
  46  *
  47  * Note:
  48  * YCbCr is defined per CCIR 601-1, except that Cb and Cr are
  49  * normalized to the range 0..MAXJSAMPLE rather than -0.5 .. 0.5.
  50  * The conversion equations to be implemented are therefore
  51  *      R = Y                + 1.40200 * Cr
  52  *      G = Y - 0.34414 * Cb - 0.71414 * Cr
  53  *      B = Y + 1.77200 * Cb
  54  *
  55  ******************************************************************************/
  56 static unsigned char clamp(int i)
  57 {
  58   if (i<0)
  59     return 0;
  60   else if (i>255)
  61     return 255;
  62   else
  63     return i;
  64 }
  65
  66 /**
  67  *  YCrCb -> BGRA32 (1x1)
  68  *  .---.
  69  *  | 1 |
  70  *  `---'
  71  */
  72 static void YCrCB_to_BGRA32_1x1(struct jdec_private *priv)
  73 {
  74   const unsigned char *Y, *Cb, *Cr;
  75   unsigned char *p;
  76   int i,j;
  77   int offset_to_next_row;
  78
  79 #define SCALEBITS       10
  80 #define ONE_HALF        (1UL << (SCALEBITS-1))
  81 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
  82
  83   p = priv->plane[0];
  84   Y = priv->Y;
  85   Cb = priv->Cb;
  86   Cr = priv->Cr;
  87   offset_to_next_row = priv->bytes_per_row[0] - 8*4;
  88   for (i=0; i<8; i++) {
  89
  90     for (j=0;j<8;j++) {
  91
  92        int y, cb, cr;
  93        int add_r, add_g, add_b;
  94        int r, g , b, a;
  95
  96        y  = (*Y++) << SCALEBITS;
  97        cb = *Cb++ - 128;
  98        cr = *Cr++ - 128;
  99        add_r = FIX(1.40200) * cr + ONE_HALF;
 100        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 101        add_b = FIX(1.77200) * cb + ONE_HALF;
 102
 103        b = (y + add_b) >> SCALEBITS;
 104        *p++ = clamp(b);
 105        g = (y + add_g) >> SCALEBITS;
 106        *p++ = clamp(g);
 107        r = (y + add_r) >> SCALEBITS;
 108        *p++ = clamp(r);
 109        a = 255;
 110        *p++ = a;
 111
 112     }
 113
 114     p += offset_to_next_row;
 115   }
 116
 117 #undef SCALEBITS
 118 #undef ONE_HALF
 119 #undef FIX
 120
 121 }
 122
 123
 124 /*
 125  *  YCrCb -> BGRA32 (2x1)
 126  *  .-------.
 127  *  | 1 | 2 |
 128  *  `-------'
 129  */
 130 static void YCrCB_to_BGRA32_2x1(struct jdec_private *priv)
 131 {
 132   const unsigned char *Y, *Cb, *Cr;
 133   unsigned char *p;
 134   int i,j;
 135   int offset_to_next_row;
 136
 137 #define SCALEBITS       10
 138 #define ONE_HALF        (1UL << (SCALEBITS-1))
 139 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
 140
 141   p = priv->plane[0];
 142   Y = priv->Y;
 143   Cb = priv->Cb;
 144   Cr = priv->Cr;
 145   offset_to_next_row = priv->bytes_per_row[0] - 16*4;
 146   for (i=0; i<8; i++) {
 147
 148     for (j=0; j<8; j++) {
 149
 150        int y, cb, cr;
 151        int add_r, add_g, add_b;
 152        int r, g , b, a;
 153
 154        cb = *Cb++ - 128;
 155        cr = *Cr++ - 128;
 156        add_r = FIX(1.40200) * cr + ONE_HALF;
 157        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 158        add_b = FIX(1.77200) * cb + ONE_HALF;
 159
 160        y  = (*Y++) << SCALEBITS;
 161        b = (y + add_b) >> SCALEBITS;
 162        *p++ = clamp(b);
 163        g = (y + add_g) >> SCALEBITS;
 164        *p++ = clamp(g);
 165        r = (y + add_r) >> SCALEBITS;
 166        *p++ = clamp(r);
 167        a = 255;
 168        *p++ = a;
 169
 170        y  = (*Y++) << SCALEBITS;
 171        b = (y + add_b) >> SCALEBITS;
 172        *p++ = clamp(b);
 173        g = (y + add_g) >> SCALEBITS;
 174        *p++ = clamp(g);
 175        r = (y + add_r) >> SCALEBITS;
 176        *p++ = clamp(r);
 177        a = 255;
 178        *p++ = a;
 179
 180     }
 181
 182     p += offset_to_next_row;
 183   }
 184
 185 #undef SCALEBITS
 186 #undef ONE_HALF
 187 #undef FIX
 188
 189 }
 190
 191 /*
 192  *  YCrCb -> BGRA32 (1x2)
 193  *  .---.
 194  *  | 1 |
 195  *  |---|
 196  *  | 2 |
 197  *  `---'
 198  */
 199 static void YCrCB_to_BGRA32_1x2(struct jdec_private *priv)
 200 {
 201   const unsigned char *Y, *Cb, *Cr;
 202   unsigned char *p, *p2;
 203   int i,j;
 204   int offset_to_next_row;
 205
 206 #define SCALEBITS       10
 207 #define ONE_HALF        (1UL << (SCALEBITS-1))
 208 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
 209
 210   p = priv->plane[0];
 211   p2 = priv->plane[0] + priv->bytes_per_row[0];
 212   Y = priv->Y;
 213   Cb = priv->Cb;
 214   Cr = priv->Cr;
 215   offset_to_next_row = 2*priv->bytes_per_row[0] - 8*4;
 216   for (i=0; i<8; i++) {
 217
 218     for (j=0; j<8; j++) {
 219
 220        int y, cb, cr;
 221        int add_r, add_g, add_b;
 222        int r, g , b, a;
 223
 224        cb = *Cb++ - 128;
 225        cr = *Cr++ - 128;
 226        add_r = FIX(1.40200) * cr + ONE_HALF;
 227        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 228        add_b = FIX(1.77200) * cb + ONE_HALF;
 229
 230        y  = (*Y++) << SCALEBITS;
 231        b = (y + add_b) >> SCALEBITS;
 232        *p++ = clamp(b);
 233        g = (y + add_g) >> SCALEBITS;
 234        *p++ = clamp(g);
 235        r = (y + add_r) >> SCALEBITS;
 236        *p++ = clamp(r);
 237        a = 255;
 238        *p++ = a;
 239
 240        y  = (Y[8-1]) << SCALEBITS;
 241        b = (y + add_b) >> SCALEBITS;
 242        *p2++ = clamp(b);
 243        g = (y + add_g) >> SCALEBITS;
 244        *p2++ = clamp(g);
 245        r = (y + add_r) >> SCALEBITS;
 246        *p2++ = clamp(r);
 247        a = 255;
 248        *p2++ = a;
 249
 250     }
 251     Y += 8;
 252     p += offset_to_next_row;
 253     p2 += offset_to_next_row;
 254   }
 255
 256 #undef SCALEBITS
 257 #undef ONE_HALF
 258 #undef FIX
 259
 260 }
 261
 262
 263 /*
 264  *  YCrCb -> BGRA32 (2x2)
 265  *  .-------.
 266  *  | 1 | 2 |
 267  *  |---+---|
 268  *  | 3 | 4 |
 269  *  `-------'
 270  */
 271 static void YCrCB_to_BGRA32_2x2(struct jdec_private *priv)
 272 {
 273   const unsigned char *Y, *Cb, *Cr;
 274   unsigned char *p, *p2;
 275   int i,j;
 276   int offset_to_next_row;
 277
 278 #define SCALEBITS       10
 279 #define ONE_HALF        (1UL << (SCALEBITS-1))
 280 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
 281
 282   p = priv->plane[0];
 283   p2 = priv->plane[0] + priv->bytes_per_row[0];
 284   Y = priv->Y;
 285   Cb = priv->Cb;
 286   Cr = priv->Cr;
 287   offset_to_next_row = 2*priv->bytes_per_row[0] - 16*4;
 288   for (i=0; i<8; i++) {
 289
 290     for (j=0;j<8;j++) {
 291
 292        int y, cb, cr;
 293        int add_r, add_g, add_b;
 294        int r, g , b, a;
 295
 296        cb = *Cb++ - 128;
 297        cr = *Cr++ - 128;
 298        add_r = FIX(1.40200) * cr + ONE_HALF;
 299        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 300        add_b = FIX(1.77200) * cb + ONE_HALF;
 301
 302        y  = (*Y++) << SCALEBITS;
 303        b = (y + add_b) >> SCALEBITS;
 304        *p++ = clamp(b);
 305        g = (y + add_g) >> SCALEBITS;
 306        *p++ = clamp(g);
 307        r = (y + add_r) >> SCALEBITS;
 308        *p++ = clamp(r);
 309        a = 255;
 310        *p++ = a;
 311
 312        y  = (*Y++) << SCALEBITS;
 313        b = (y + add_b) >> SCALEBITS;
 314        *p++ = clamp(b);
 315        g = (y + add_g) >> SCALEBITS;
 316        *p++ = clamp(g);
 317        r = (y + add_r) >> SCALEBITS;
 318        *p++ = clamp(r);
 319        a = 255;
 320        *p++ = a;
 321
 322        y  = (Y[16-2]) << SCALEBITS;
 323        b = (y + add_b) >> SCALEBITS;
 324        *p2++ = clamp(b);
 325        g = (y + add_g) >> SCALEBITS;
 326        *p2++ = clamp(g);
 327        r = (y + add_r) >> SCALEBITS;
 328        *p2++ = clamp(r);
 329        a = 255;
 330        *p2++ = a;
 331
 332        y  = (Y[16-1]) << SCALEBITS;
 333        b = (y + add_b) >> SCALEBITS;
 334        *p2++ = clamp(b);
 335        g = (y + add_g) >> SCALEBITS;
 336        *p2++ = clamp(g);
 337        r = (y + add_r) >> SCALEBITS;
 338        *p2++ = clamp(r);
 339        a = 255;
 340        *p2++ = a;
 341     }
 342     Y  += 16;
 343     p  += offset_to_next_row;
 344     p2 += offset_to_next_row;
 345   }
 346
 347 #undef SCALEBITS
 348 #undef ONE_HALF
 349 #undef FIX
 350
 351 }
 352
 353 static int initialize_bgra32(struct jdec_private *priv,
 354                              unsigned int *bytes_per_blocklines,
 355                              unsigned int *bytes_per_mcu)
 356 {
 357   if (priv->components[0] == NULL)
 358     priv->components[0] = (uint8_t *)malloc(priv->width * priv->height * 4);
 359   if (!priv->bytes_per_row[0])
 360     priv->bytes_per_row[0] = priv->width * 4;
 361
 362   bytes_per_blocklines[0] = priv->bytes_per_row[0];
 363   bytes_per_mcu[0] = 4*8;
 364
 365   return !priv->components[0];
 366 }
 367
 368 static const struct tinyjpeg_colorspace format_bgra32 =
 369   {
 370     {
 371       YCrCB_to_BGRA32_1x1,
 372       YCrCB_to_BGRA32_1x2,
 373       YCrCB_to_BGRA32_2x1,
 374       YCrCB_to_BGRA32_2x2,
 375     },
 376     tinyjpeg_decode_mcu_3comp_table,
 377     initialize_bgra32
 378   };
 379
 380 const tinyjpeg_colorspace_t TINYJPEG_FMT_BGRA32 = &format_bgra32;