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, int sx, int sy)
  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 = sy; i > 0; i--) {
  89     for (j = sx; j > 0; j--) {
  90
  91        int y, cb, cr;
  92        int add_r, add_g, add_b;
  93        int r, g , b, a;
  94
  95        y  = Y[0] << SCALEBITS;
  96        cb = *Cb++ - 128;
  97        cr = *Cr++ - 128;
  98        add_r = FIX(1.40200) * cr + ONE_HALF;
  99        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 100        add_b = FIX(1.77200) * cb + ONE_HALF;
 101
 102        b = (y + add_b) >> SCALEBITS;
 103        *p++ = clamp(b);
 104        g = (y + add_g) >> SCALEBITS;
 105        *p++ = clamp(g);
 106        r = (y + add_r) >> SCALEBITS;
 107        *p++ = clamp(r);
 108        a = 255;
 109        *p++ = a;
 110
 111        Y++;
 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, int sx, int sy)
 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 = sy; i > 0; i--) {
 147     for (j = sx; j > 0; j -= 2) {
 148        int y, cb, cr;
 149        int add_r, add_g, add_b;
 150        int r, g , b, a;
 151
 152        cb = *Cb++ - 128;
 153        cr = *Cr++ - 128;
 154        add_r = FIX(1.40200) * cr + ONE_HALF;
 155        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 156        add_b = FIX(1.77200) * cb + ONE_HALF;
 157
 158        y  = Y[0] << SCALEBITS;
 159        b = (y + add_b) >> SCALEBITS;
 160        *p++ = clamp(b);
 161        g = (y + add_g) >> SCALEBITS;
 162        *p++ = clamp(g);
 163        r = (y + add_r) >> SCALEBITS;
 164        *p++ = clamp(r);
 165        a = 255;
 166        *p++ = a;
 167
 168        if (j > 1) {
 169            y  = Y[1] << SCALEBITS;
 170            b = (y + add_b) >> SCALEBITS;
 171            *p++ = clamp(b);
 172            g = (y + add_g) >> SCALEBITS;
 173            *p++ = clamp(g);
 174            r = (y + add_r) >> SCALEBITS;
 175            *p++ = clamp(r);
 176            a = 255;
 177            *p++ = a;
 178        }
 179
 180        Y += 2;
 181     }
 182
 183     p += offset_to_next_row;
 184   }
 185
 186 #undef SCALEBITS
 187 #undef ONE_HALF
 188 #undef FIX
 189
 190 }
 191
 192 /*
 193  *  YCrCb -> BGRA32 (1x2)
 194  *  .---.
 195  *  | 1 |
 196  *  |---|
 197  *  | 2 |
 198  *  `---'
 199  */
 200 static void YCrCB_to_BGRA32_1x2(struct jdec_private *priv, int sx, int sy)
 201 {
 202   const unsigned char *Y, *Cb, *Cr;
 203   unsigned char *p, *p2;
 204   int i,j;
 205   int offset_to_next_row;
 206
 207 #define SCALEBITS       10
 208 #define ONE_HALF        (1UL << (SCALEBITS-1))
 209 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
 210
 211   p = priv->plane[0];
 212   p2 = priv->plane[0] + priv->bytes_per_row[0];
 213   Y = priv->Y;
 214   Cb = priv->Cb;
 215   Cr = priv->Cr;
 216   offset_to_next_row = 2*priv->bytes_per_row[0] - 8*4;
 217   for (i = sy; i > 0; i -= 2) {
 218     for (j = sx; j > 0; 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[0] << 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        if (i > 1) {
 241            y  = Y[8] << SCALEBITS;
 242            b = (y + add_b) >> SCALEBITS;
 243            *p2++ = clamp(b);
 244            g = (y + add_g) >> SCALEBITS;
 245            *p2++ = clamp(g);
 246            r = (y + add_r) >> SCALEBITS;
 247            *p2++ = clamp(r);
 248            a = 255;
 249            *p2++ = a;
 250        }
 251
 252        Y++;
 253     }
 254     Y += 8;
 255     p += offset_to_next_row;
 256     p2 += offset_to_next_row;
 257   }
 258
 259 #undef SCALEBITS
 260 #undef ONE_HALF
 261 #undef FIX
 262
 263 }
 264
 265
 266 /*
 267  *  YCrCb -> BGRA32 (2x2)
 268  *  .-------.
 269  *  | 1 | 2 |
 270  *  |---+---|
 271  *  | 3 | 4 |
 272  *  `-------'
 273  */
 274 static void YCrCB_to_BGRA32_2x2(struct jdec_private *priv, int sx, int sy)
 275 {
 276   const unsigned char *Y, *Cb, *Cr;
 277   unsigned char *p, *p2;
 278   int i,j;
 279   int offset_to_next_row;
 280
 281 #define SCALEBITS       10
 282 #define ONE_HALF        (1UL << (SCALEBITS-1))
 283 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
 284
 285   p = priv->plane[0];
 286   p2 = priv->plane[0] + priv->bytes_per_row[0];
 287   Y = priv->Y;
 288   Cb = priv->Cb;
 289   Cr = priv->Cr;
 290   offset_to_next_row = 2*priv->bytes_per_row[0] - 16*4;
 291   for (i = sy; i > 0; i -= 2) {
 292     for (j = sx; j > 0; j -= 2) {
 293
 294        int y, cb, cr;
 295        int add_r, add_g, add_b;
 296        int r, g , b, a;
 297
 298        cb = *Cb++ - 128;
 299        cr = *Cr++ - 128;
 300        add_r = FIX(1.40200) * cr + ONE_HALF;
 301        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 302        add_b = FIX(1.77200) * cb + ONE_HALF;
 303
 304        y  = Y[0] << SCALEBITS;
 305        b = (y + add_b) >> SCALEBITS;
 306        *p++ = clamp(b);
 307        g = (y + add_g) >> SCALEBITS;
 308        *p++ = clamp(g);
 309        r = (y + add_r) >> SCALEBITS;
 310        *p++ = clamp(r);
 311        a = 255;
 312        *p++ = a;
 313
 314        if (j > 1) {
 315            y  = Y[1] << SCALEBITS;
 316            b = (y + add_b) >> SCALEBITS;
 317            *p++ = clamp(b);
 318            g = (y + add_g) >> SCALEBITS;
 319            *p++ = clamp(g);
 320            r = (y + add_r) >> SCALEBITS;
 321            *p++ = clamp(r);
 322            a = 255;
 323            *p++ = a;
 324        }
 325
 326        if (i > 1) {
 327            y  = Y[16+0] << SCALEBITS;
 328            b = (y + add_b) >> SCALEBITS;
 329            *p2++ = clamp(b);
 330            g = (y + add_g) >> SCALEBITS;
 331            *p2++ = clamp(g);
 332            r = (y + add_r) >> SCALEBITS;
 333            *p2++ = clamp(r);
 334            a = 255;
 335            *p2++ = a;
 336
 337            if (j > 1) {
 338                y  = Y[16+1] << SCALEBITS;
 339                b = (y + add_b) >> SCALEBITS;
 340                *p2++ = clamp(b);
 341                g = (y + add_g) >> SCALEBITS;
 342                *p2++ = clamp(g);
 343                r = (y + add_r) >> SCALEBITS;
 344                *p2++ = clamp(r);
 345                a = 255;
 346                *p2++ = a;
 347            }
 348        }
 349
 350        Y += 2;
 351     }
 352     Y  += 16;
 353     p  += offset_to_next_row;
 354     p2 += offset_to_next_row;
 355   }
 356
 357 #undef SCALEBITS
 358 #undef ONE_HALF
 359 #undef FIX
 360
 361 }
 362
 363 static int initialize_bgra32(struct jdec_private *priv,
 364                              unsigned int *bytes_per_blocklines,
 365                              unsigned int *bytes_per_mcu)
 366 {
 367   if (!priv->bytes_per_row[0])
 368     priv->bytes_per_row[0] = priv->width * 4;
 369   if (!priv->components[0])
 370     priv->components[0] = malloc(priv->height * priv->bytes_per_row[0]);
 371
 372   bytes_per_blocklines[0] = priv->bytes_per_row[0] << 3;
 373   bytes_per_mcu[0] = 4*8;
 374
 375   return !priv->components[0];
 376 }
 377
 378 static const struct tinyjpeg_colorspace format_bgra32 =
 379   {
 380     {
 381       YCrCB_to_BGRA32_1x1,
 382       YCrCB_to_BGRA32_1x2,
 383       YCrCB_to_BGRA32_2x1,
 384       YCrCB_to_BGRA32_2x2,
 385     },
 386     tinyjpeg_decode_mcu_3comp_table,
 387     initialize_bgra32
 388   };
 389
 390 const tinyjpeg_colorspace_t TINYJPEG_FMT_BGRA32 = &format_bgra32;