com32/lib/jpeg/rgba32.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 -> RGBA32 (1x1)
  68  *  .---.
  69  *  | 1 |
  70  *  `---'
  71  */
  72 static void YCrCB_to_RGBA32_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        r = (y + add_r) >> SCALEBITS;
 103        *p++ = clamp(r);
 104        g = (y + add_g) >> SCALEBITS;
 105        *p++ = clamp(g);
 106        b = (y + add_b) >> SCALEBITS;
 107        *p++ = clamp(b);
 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  *  YCrCb -> RGBA32 (2x1)
 125  *  .-------.
 126  *  | 1 | 2 |
 127  *  `-------'
 128  */
 129 static void YCrCB_to_RGBA32_2x1(struct jdec_private *priv, int sx, int sy)
 130 {
 131   const unsigned char *Y, *Cb, *Cr;
 132   unsigned char *p;
 133   int i,j;
 134   int offset_to_next_row;
 135
 136 #define SCALEBITS       10
 137 #define ONE_HALF        (1UL << (SCALEBITS-1))
 138 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
 139
 140   p = priv->plane[0];
 141   Y = priv->Y;
 142   Cb = priv->Cb;
 143   Cr = priv->Cr;
 144   offset_to_next_row = priv->bytes_per_row[0] - 16*4;
 145   for (i = sy; i > 0; i--) {
 146     for (j = sx; j > 0; j -= 2) {
 147
 148        int y, cb, cr;
 149        int add_r, add_g, add_b;
 150        int r, g , b, a;
 151
 152        y  = Y[0] << SCALEBITS;
 153        cb = *Cb++ - 128;
 154        cr = *Cr++ - 128;
 155        add_r = FIX(1.40200) * cr + ONE_HALF;
 156        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 157        add_b = FIX(1.77200) * cb + ONE_HALF;
 158
 159        r = (y + add_r) >> SCALEBITS;
 160        *p++ = clamp(r);
 161        g = (y + add_g) >> SCALEBITS;
 162        *p++ = clamp(g);
 163        b = (y + add_b) >> SCALEBITS;
 164        *p++ = clamp(b);
 165        a = 255;
 166        *p++ = a;
 167
 168        if (j > 1) {
 169            y  = Y[1] << SCALEBITS;
 170            r = (y + add_r) >> SCALEBITS;
 171            *p++ = clamp(r);
 172            g = (y + add_g) >> SCALEBITS;
 173            *p++ = clamp(g);
 174            b = (y + add_b) >> SCALEBITS;
 175            *p++ = clamp(b);
 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 /**
 194  *  YCrCb -> RGBA32 (1x2)
 195  *  .---.
 196  *  | 1 |
 197  *  |---|
 198  *  | 2 |
 199  *  `---'
 200  */
 201 static void YCrCB_to_RGBA32_1x2(struct jdec_private *priv, int sx, int sy)
 202 {
 203   const unsigned char *Y, *Cb, *Cr;
 204   unsigned char *p, *p2;
 205   int i,j;
 206   int offset_to_next_row;
 207
 208 #define SCALEBITS       10
 209 #define ONE_HALF        (1UL << (SCALEBITS-1))
 210 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
 211
 212   p = priv->plane[0];
 213   p2 = priv->plane[0] + priv->bytes_per_row[0];
 214   Y = priv->Y;
 215   Cb = priv->Cb;
 216   Cr = priv->Cr;
 217   offset_to_next_row = 2*priv->bytes_per_row[0] - 8*4;
 218   for (i = sy; i > 0; i -= 2) {
 219     for (j = sx; j > 0; j--) {
 220
 221        int y, cb, cr;
 222        int add_r, add_g, add_b;
 223        int r, g , b, a;
 224
 225        cb = *Cb++ - 128;
 226        cr = *Cr++ - 128;
 227        add_r = FIX(1.40200) * cr + ONE_HALF;
 228        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 229        add_b = FIX(1.77200) * cb + ONE_HALF;
 230
 231        y  = Y[0] << SCALEBITS;
 232        r = (y + add_r) >> SCALEBITS;
 233        *p++ = clamp(r);
 234        g = (y + add_g) >> SCALEBITS;
 235        *p++ = clamp(g);
 236        b = (y + add_b) >> SCALEBITS;
 237        *p++ = clamp(b);
 238        a = 255;
 239        *p++ = a;
 240
 241        if (i > 1) {
 242            y  = Y[8] << SCALEBITS;
 243            r = (y + add_r) >> SCALEBITS;
 244            *p2++ = clamp(r);
 245            g = (y + add_g) >> SCALEBITS;
 246            *p2++ = clamp(g);
 247            b = (y + add_b) >> SCALEBITS;
 248            *p2++ = clamp(b);
 249            a = 255;
 250            *p2++ = a;
 251        }
 252
 253        Y++;
 254     }
 255     Y += 8;
 256     p += offset_to_next_row;
 257     p2 += offset_to_next_row;
 258   }
 259
 260 #undef SCALEBITS
 261 #undef ONE_HALF
 262 #undef FIX
 263
 264 }
 265
 266 /**
 267  *  YCrCb -> RGBA32 (2x2)
 268  *  .-------.
 269  *  | 1 | 2 |
 270  *  |---+---|
 271  *  | 3 | 4 |
 272  *  `-------'
 273  */
 274 static void YCrCB_to_RGBA32_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; i > 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        r = (y + add_r) >> SCALEBITS;
 306        *p++ = clamp(r);
 307        g = (y + add_g) >> SCALEBITS;
 308        *p++ = clamp(g);
 309        b = (y + add_b) >> SCALEBITS;
 310        *p++ = clamp(b);
 311        a = 255;
 312        *p++ = a;
 313
 314        if (j > 1) {
 315            y  = Y[1] << SCALEBITS;
 316            r = (y + add_r) >> SCALEBITS;
 317            *p++ = clamp(r);
 318            g = (y + add_g) >> SCALEBITS;
 319            *p++ = clamp(g);
 320            b = (y + add_b) >> SCALEBITS;
 321            *p++ = clamp(b);
 322            a = 255;
 323            *p++ = a;
 324        }
 325
 326        if (i > 1) {
 327            y  = Y[16+0] << SCALEBITS;
 328            r = (y + add_r) >> SCALEBITS;
 329            *p2++ = clamp(r);
 330            g = (y + add_g) >> SCALEBITS;
 331            *p2++ = clamp(g);
 332            b = (y + add_b) >> SCALEBITS;
 333            *p2++ = clamp(b);
 334            a = 255;
 335            *p2++ = a;
 336
 337            if (j > 1) {
 338                y  = Y[16+1] << SCALEBITS;
 339                r = (y + add_r) >> SCALEBITS;
 340                *p2++ = clamp(r);
 341                g = (y + add_g) >> SCALEBITS;
 342                *p2++ = clamp(g);
 343                b = (y + add_b) >> SCALEBITS;
 344                *p2++ = clamp(b);
 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_rgba32(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_rgba32 =
 379   {
 380     {
 381       YCrCB_to_RGBA32_1x1,
 382       YCrCB_to_RGBA32_1x2,
 383       YCrCB_to_RGBA32_2x1,
 384       YCrCB_to_RGBA32_2x2,
 385     },
 386     tinyjpeg_decode_mcu_3comp_table,
 387     initialize_rgba32
 388   };
 389
 390 const tinyjpeg_colorspace_t TINYJPEG_FMT_RGBA32 = &format_rgba32;