git.sesse.net Git - vlc/blob - modules/video_chroma/i420_rgb.c

   1 /*****************************************************************************
   2  * i420_rgb.c : YUV to bitmap RGB conversion module for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2000, 2001, 2004, 2008 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Sam Hocevar <sam@zoy.org>
   8  *          Damien Fouilleul <damienf@videolan.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28
  29 #ifdef HAVE_CONFIG_H
  30 # include "config.h"
  31 #endif
  32
  33 #include <math.h>                                            /* exp(), pow() */
  34
  35 #include <vlc_common.h>
  36 #include <vlc_plugin.h>
  37 #include <vlc_filter.h>
  38 #include <vlc_cpu.h>
  39
  40 #include "i420_rgb.h"
  41 #if defined (MODULE_NAME_IS_i420_rgb)
  42 #   include "i420_rgb_c.h"
  43     static picture_t *I420_RGB8_Filter         ( filter_t *, picture_t * );
  44 //    static picture_t *I420_RGB16_dither_Filter ( filter_t *, picture_t * );
  45     static picture_t *I420_RGB16_Filter        ( filter_t *, picture_t * );
  46     static picture_t *I420_RGB32_Filter        ( filter_t *, picture_t * );
  47 #else
  48     static picture_t *I420_R5G5B5_Filter       ( filter_t *, picture_t * );
  49     static picture_t *I420_R5G6B5_Filter       ( filter_t *, picture_t * );
  50     static picture_t *I420_A8R8G8B8_Filter     ( filter_t *, picture_t * );
  51     static picture_t *I420_R8G8B8A8_Filter     ( filter_t *, picture_t * );
  52     static picture_t *I420_B8G8R8A8_Filter     ( filter_t *, picture_t * );
  53     static picture_t *I420_A8B8G8R8_Filter     ( filter_t *, picture_t * );
  54 #endif
  55
  56 /*****************************************************************************
  57  * RGB2PIXEL: assemble RGB components to a pixel value, returns a uint32_t
  58  *****************************************************************************/
  59 #define RGB2PIXEL( p_filter, i_r, i_g, i_b )                 \
  60     (((((uint32_t)i_r) >> p_filter->fmt_out.video.i_rrshift) \
  61                        << p_filter->fmt_out.video.i_lrshift) \
  62    | ((((uint32_t)i_g) >> p_filter->fmt_out.video.i_rgshift) \
  63                        << p_filter->fmt_out.video.i_lgshift) \
  64    | ((((uint32_t)i_b) >> p_filter->fmt_out.video.i_rbshift) \
  65                        << p_filter->fmt_out.video.i_lbshift))
  66
  67 /*****************************************************************************
  68  * Local and extern prototypes.
  69  *****************************************************************************/
  70 static int  Activate   ( vlc_object_t * );
  71 static void Deactivate ( vlc_object_t * );
  72
  73 #if defined (MODULE_NAME_IS_i420_rgb)
  74 static void SetGammaTable       ( int *pi_table, double f_gamma );
  75 static void SetYUV              ( filter_t * );
  76 static void Set8bppPalette      ( filter_t *, uint8_t * );
  77 #endif
  78
  79 /*****************************************************************************
  80  * Module descriptor.
  81  *****************************************************************************/
  82 vlc_module_begin ()
  83 #if defined (MODULE_NAME_IS_i420_rgb)
  84     set_description( N_("I420,IYUV,YV12 to "
  85                        "RGB2,RV15,RV16,RV24,RV32 conversions") )
  86     set_capability( "video filter2", 80 )
  87 # define CPU_CAPABILITY 0
  88 #elif defined (MODULE_NAME_IS_i420_rgb_mmx)
  89     set_description( N_( "MMX I420,IYUV,YV12 to "
  90                         "RV15,RV16,RV24,RV32 conversions") )
  91     set_capability( "video filter2", 100 )
  92 # define CPU_CAPABILITY CPU_CAPABILITY_MMX
  93 #elif defined (MODULE_NAME_IS_i420_rgb_sse2)
  94     set_description( N_( "SSE2 I420,IYUV,YV12 to "
  95                         "RV15,RV16,RV24,RV32 conversions") )
  96     set_capability( "video filter2", 120 )
  97 # define CPU_CAPABILITY CPU_CAPABILITY_SSE2
  98 #endif
  99     set_callbacks( Activate, Deactivate )
 100 vlc_module_end ()
 101
 102 /*****************************************************************************
 103  * Activate: allocate a chroma function
 104  *****************************************************************************
 105  * This function allocates and initializes a chroma function
 106  *****************************************************************************/
 107 static int Activate( vlc_object_t *p_this )
 108 {
 109     filter_t *p_filter = (filter_t *)p_this;
 110 #if defined (MODULE_NAME_IS_i420_rgb)
 111     size_t i_tables_size;
 112 #endif
 113
 114 #if CPU_CAPABILITY
 115     if( !(vlc_CPU() & CPU_CAPABILITY) )
 116         return VLC_EGENERIC;
 117 #endif
 118     if( p_filter->fmt_out.video.i_width & 1
 119      || p_filter->fmt_out.video.i_height & 1 )
 120     {
 121         return VLC_EGENERIC;
 122     }
 123
 124     switch( p_filter->fmt_in.video.i_chroma )
 125     {
 126         case VLC_CODEC_YV12:
 127         case VLC_CODEC_I420:
 128             switch( p_filter->fmt_out.video.i_chroma )
 129             {
 130 #if defined (MODULE_NAME_IS_i420_rgb)
 131                 case VLC_CODEC_RGB8:
 132                     p_filter->pf_video_filter = I420_RGB8_Filter;
 133                     break;
 134 #endif
 135                 case VLC_CODEC_RGB15:
 136                 case VLC_CODEC_RGB16:
 137 #if ! defined (MODULE_NAME_IS_i420_rgb)
 138                     /* If we don't have support for the bitmasks, bail out */
 139                     if( ( p_filter->fmt_out.video.i_rmask == 0x7c00
 140                        && p_filter->fmt_out.video.i_gmask == 0x03e0
 141                        && p_filter->fmt_out.video.i_bmask == 0x001f ) )
 142                     {
 143                         /* R5G5B6 pixel format */
 144                         msg_Dbg(p_this, "RGB pixel format is R5G5B5");
 145                         p_filter->pf_video_filter = I420_R5G5B5_Filter;
 146                     }
 147                     else if( ( p_filter->fmt_out.video.i_rmask == 0xf800
 148                             && p_filter->fmt_out.video.i_gmask == 0x07e0
 149                             && p_filter->fmt_out.video.i_bmask == 0x001f ) )
 150                     {
 151                         /* R5G6B5 pixel format */
 152                         msg_Dbg(p_this, "RGB pixel format is R5G6B5");
 153                         p_filter->pf_video_filter = I420_R5G6B5_Filter;
 154                     }
 155                     else
 156                         return VLC_EGENERIC;
 157 #else
 158                     // generic C chroma converter */
 159                     p_filter->pf_video_filter = I420_RGB16_Filter;
 160 #endif
 161                     break;
 162
 163 #if 0
 164                 /* Hmmm, is there only X11 using 32bits per pixel for RV24 ? */
 165                 case VLC_CODEC_RGB24:
 166 #endif
 167
 168                 case VLC_CODEC_RGB32:
 169 #if ! defined (MODULE_NAME_IS_i420_rgb)
 170                     /* If we don't have support for the bitmasks, bail out */
 171                     if( p_filter->fmt_out.video.i_rmask == 0x00ff0000
 172                      && p_filter->fmt_out.video.i_gmask == 0x0000ff00
 173                      && p_filter->fmt_out.video.i_bmask == 0x000000ff )
 174                     {
 175                         /* A8R8G8B8 pixel format */
 176                         msg_Dbg(p_this, "RGB pixel format is A8R8G8B8");
 177                         p_filter->pf_video_filter = I420_A8R8G8B8_Filter;
 178                     }
 179                     else if( p_filter->fmt_out.video.i_rmask == 0xff000000
 180                           && p_filter->fmt_out.video.i_gmask == 0x00ff0000
 181                           && p_filter->fmt_out.video.i_bmask == 0x0000ff00 )
 182                     {
 183                         /* R8G8B8A8 pixel format */
 184                         msg_Dbg(p_this, "RGB pixel format is R8G8B8A8");
 185                         p_filter->pf_video_filter = I420_R8G8B8A8_Filter;
 186                     }
 187                     else if( p_filter->fmt_out.video.i_rmask == 0x0000ff00
 188                           && p_filter->fmt_out.video.i_gmask == 0x00ff0000
 189                           && p_filter->fmt_out.video.i_bmask == 0xff000000 )
 190                     {
 191                         /* B8G8R8A8 pixel format */
 192                         msg_Dbg(p_this, "RGB pixel format is B8G8R8A8");
 193                         p_filter->pf_video_filter = I420_B8G8R8A8_Filter;
 194                     }
 195                     else if( p_filter->fmt_out.video.i_rmask == 0x000000ff
 196                           && p_filter->fmt_out.video.i_gmask == 0x0000ff00
 197                           && p_filter->fmt_out.video.i_bmask == 0x00ff0000 )
 198                     {
 199                         /* A8B8G8R8 pixel format */
 200                         msg_Dbg(p_this, "RGB pixel format is A8B8G8R8");
 201                         p_filter->pf_video_filter = I420_A8B8G8R8_Filter;
 202                     }
 203                     else
 204                         return VLC_EGENERIC;
 205 #else
 206                     /* generic C chroma converter */
 207                     p_filter->pf_video_filter = I420_RGB32_Filter;
 208 #endif
 209                     break;
 210
 211                 default:
 212                     return VLC_EGENERIC;
 213             }
 214             break;
 215
 216         default:
 217             return VLC_EGENERIC;
 218     }
 219
 220     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 221     if( p_filter->p_sys == NULL )
 222     {
 223         return VLC_EGENERIC;
 224     }
 225
 226     switch( p_filter->fmt_out.video.i_chroma )
 227     {
 228 #if defined (MODULE_NAME_IS_i420_rgb)
 229         case VLC_CODEC_RGB8:
 230             p_filter->p_sys->p_buffer = malloc( VOUT_MAX_WIDTH );
 231             break;
 232 #endif
 233
 234         case VLC_CODEC_RGB15:
 235         case VLC_CODEC_RGB16:
 236             p_filter->p_sys->p_buffer = malloc( VOUT_MAX_WIDTH * 2 );
 237             break;
 238
 239         case VLC_CODEC_RGB24:
 240         case VLC_CODEC_RGB32:
 241             p_filter->p_sys->p_buffer = malloc( VOUT_MAX_WIDTH * 4 );
 242             break;
 243
 244         default:
 245             p_filter->p_sys->p_buffer = NULL;
 246             break;
 247     }
 248
 249     if( p_filter->p_sys->p_buffer == NULL )
 250     {
 251         free( p_filter->p_sys );
 252         return VLC_EGENERIC;
 253     }
 254
 255     p_filter->p_sys->p_offset = malloc( p_filter->fmt_out.video.i_width
 256                     * ( ( p_filter->fmt_out.video.i_chroma
 257                            == VLC_CODEC_RGB8 ) ? 2 : 1 )
 258                     * sizeof( int ) );
 259     if( p_filter->p_sys->p_offset == NULL )
 260     {
 261         free( p_filter->p_sys->p_buffer );
 262         free( p_filter->p_sys );
 263         return VLC_EGENERIC;
 264     }
 265
 266 #if defined (MODULE_NAME_IS_i420_rgb)
 267     switch( p_filter->fmt_out.video.i_chroma )
 268     {
 269     case VLC_CODEC_RGB8:
 270         i_tables_size = sizeof( uint8_t ) * PALETTE_TABLE_SIZE;
 271         break;
 272     case VLC_CODEC_RGB15:
 273     case VLC_CODEC_RGB16:
 274         i_tables_size = sizeof( uint16_t ) * RGB_TABLE_SIZE;
 275         break;
 276     default: /* RV24, RV32 */
 277         i_tables_size = sizeof( uint32_t ) * RGB_TABLE_SIZE;
 278         break;
 279     }
 280
 281     p_filter->p_sys->p_base = malloc( i_tables_size );
 282     if( p_filter->p_sys->p_base == NULL )
 283     {
 284         free( p_filter->p_sys->p_offset );
 285         free( p_filter->p_sys->p_buffer );
 286         free( p_filter->p_sys );
 287         return -1;
 288     }
 289
 290     SetYUV( p_filter );
 291 #endif
 292
 293     return 0;
 294 }
 295
 296 /*****************************************************************************
 297  * Deactivate: free the chroma function
 298  *****************************************************************************
 299  * This function frees the previously allocated chroma function
 300  *****************************************************************************/
 301 static void Deactivate( vlc_object_t *p_this )
 302 {
 303     filter_t *p_filter = (filter_t *)p_this;
 304
 305 #if defined (MODULE_NAME_IS_i420_rgb)
 306     free( p_filter->p_sys->p_base );
 307 #endif
 308     free( p_filter->p_sys->p_offset );
 309     free( p_filter->p_sys->p_buffer );
 310     free( p_filter->p_sys );
 311 }
 312
 313 #if defined (MODULE_NAME_IS_i420_rgb)
 314 VIDEO_FILTER_WRAPPER( I420_RGB8 )
 315 VIDEO_FILTER_WRAPPER( I420_RGB16 )
 316 //VIDEO_FILTER_WRAPPER( I420_RGB16_dither )
 317 VIDEO_FILTER_WRAPPER( I420_RGB32 )
 318 #else
 319 VIDEO_FILTER_WRAPPER( I420_R5G5B5 )
 320 VIDEO_FILTER_WRAPPER( I420_R5G6B5 )
 321 VIDEO_FILTER_WRAPPER( I420_A8R8G8B8 )
 322 VIDEO_FILTER_WRAPPER( I420_R8G8B8A8 )
 323 VIDEO_FILTER_WRAPPER( I420_B8G8R8A8 )
 324 VIDEO_FILTER_WRAPPER( I420_A8B8G8R8 )
 325 #endif
 326
 327 #if defined (MODULE_NAME_IS_i420_rgb)
 328 /*****************************************************************************
 329  * SetGammaTable: return intensity table transformed by gamma curve.
 330  *****************************************************************************
 331  * pi_table is a table of 256 entries from 0 to 255.
 332  *****************************************************************************/
 333 static void SetGammaTable( int *pi_table, double f_gamma )
 334 {
 335     int i_y;                                               /* base intensity */
 336
 337     /* Use exp(gamma) instead of gamma */
 338     f_gamma = exp( f_gamma );
 339
 340     /* Build gamma table */
 341     for( i_y = 0; i_y < 256; i_y++ )
 342     {
 343         pi_table[ i_y ] = (int)( pow( (double)i_y / 256, f_gamma ) * 256 );
 344     }
 345 }
 346
 347 /*****************************************************************************
 348  * SetYUV: compute tables and set function pointers
 349  *****************************************************************************/
 350 static void SetYUV( filter_t *p_filter )
 351 {
 352     int          pi_gamma[256];                               /* gamma table */
 353     volatile int i_index;                                 /* index in tables */
 354                    /* We use volatile here to work around a strange gcc-3.3.4
 355                     * optimization bug */
 356
 357     /* Build gamma table */
 358     SetGammaTable( pi_gamma, 0 ); //p_filter/*FIXME wasn't used anywhere anyway*/->f_gamma );
 359
 360     /*
 361      * Set pointers and build YUV tables
 362      */
 363
 364     /* Color: build red, green and blue tables */
 365     switch( p_filter->fmt_out.video.i_chroma )
 366     {
 367     case VLC_CODEC_RGB8:
 368         p_filter->p_sys->p_rgb8 = (uint8_t *)p_filter->p_sys->p_base;
 369         Set8bppPalette( p_filter, p_filter->p_sys->p_rgb8 );
 370         break;
 371
 372     case VLC_CODEC_RGB15:
 373     case VLC_CODEC_RGB16:
 374         p_filter->p_sys->p_rgb16 = (uint16_t *)p_filter->p_sys->p_base;
 375         for( i_index = 0; i_index < RED_MARGIN; i_index++ )
 376         {
 377             p_filter->p_sys->p_rgb16[RED_OFFSET - RED_MARGIN + i_index] = RGB2PIXEL( p_filter, pi_gamma[0], 0, 0 );
 378             p_filter->p_sys->p_rgb16[RED_OFFSET + 256 + i_index] =        RGB2PIXEL( p_filter, pi_gamma[255], 0, 0 );
 379         }
 380         for( i_index = 0; i_index < GREEN_MARGIN; i_index++ )
 381         {
 382             p_filter->p_sys->p_rgb16[GREEN_OFFSET - GREEN_MARGIN + i_index] = RGB2PIXEL( p_filter, 0, pi_gamma[0], 0 );
 383             p_filter->p_sys->p_rgb16[GREEN_OFFSET + 256 + i_index] =          RGB2PIXEL( p_filter, 0, pi_gamma[255], 0 );
 384         }
 385         for( i_index = 0; i_index < BLUE_MARGIN; i_index++ )
 386         {
 387             p_filter->p_sys->p_rgb16[BLUE_OFFSET - BLUE_MARGIN + i_index] = RGB2PIXEL( p_filter, 0, 0, pi_gamma[0] );
 388             p_filter->p_sys->p_rgb16[BLUE_OFFSET + BLUE_MARGIN + i_index] = RGB2PIXEL( p_filter, 0, 0, pi_gamma[255] );
 389         }
 390         for( i_index = 0; i_index < 256; i_index++ )
 391         {
 392             p_filter->p_sys->p_rgb16[RED_OFFSET + i_index] =   RGB2PIXEL( p_filter, pi_gamma[ i_index ], 0, 0 );
 393             p_filter->p_sys->p_rgb16[GREEN_OFFSET + i_index] = RGB2PIXEL( p_filter, 0, pi_gamma[ i_index ], 0 );
 394             p_filter->p_sys->p_rgb16[BLUE_OFFSET + i_index] =  RGB2PIXEL( p_filter, 0, 0, pi_gamma[ i_index ] );
 395         }
 396         break;
 397
 398     case VLC_CODEC_RGB24:
 399     case VLC_CODEC_RGB32:
 400         p_filter->p_sys->p_rgb32 = (uint32_t *)p_filter->p_sys->p_base;
 401         for( i_index = 0; i_index < RED_MARGIN; i_index++ )
 402         {
 403             p_filter->p_sys->p_rgb32[RED_OFFSET - RED_MARGIN + i_index] = RGB2PIXEL( p_filter, pi_gamma[0], 0, 0 );
 404             p_filter->p_sys->p_rgb32[RED_OFFSET + 256 + i_index] =        RGB2PIXEL( p_filter, pi_gamma[255], 0, 0 );
 405         }
 406         for( i_index = 0; i_index < GREEN_MARGIN; i_index++ )
 407         {
 408             p_filter->p_sys->p_rgb32[GREEN_OFFSET - GREEN_MARGIN + i_index] = RGB2PIXEL( p_filter, 0, pi_gamma[0], 0 );
 409             p_filter->p_sys->p_rgb32[GREEN_OFFSET + 256 + i_index] =          RGB2PIXEL( p_filter, 0, pi_gamma[255], 0 );
 410         }
 411         for( i_index = 0; i_index < BLUE_MARGIN; i_index++ )
 412         {
 413             p_filter->p_sys->p_rgb32[BLUE_OFFSET - BLUE_MARGIN + i_index] = RGB2PIXEL( p_filter, 0, 0, pi_gamma[0] );
 414             p_filter->p_sys->p_rgb32[BLUE_OFFSET + BLUE_MARGIN + i_index] = RGB2PIXEL( p_filter, 0, 0, pi_gamma[255] );
 415         }
 416         for( i_index = 0; i_index < 256; i_index++ )
 417         {
 418             p_filter->p_sys->p_rgb32[RED_OFFSET + i_index] =   RGB2PIXEL( p_filter, pi_gamma[ i_index ], 0, 0 );
 419             p_filter->p_sys->p_rgb32[GREEN_OFFSET + i_index] = RGB2PIXEL( p_filter, 0, pi_gamma[ i_index ], 0 );
 420             p_filter->p_sys->p_rgb32[BLUE_OFFSET + i_index] =  RGB2PIXEL( p_filter, 0, 0, pi_gamma[ i_index ] );
 421         }
 422         break;
 423     }
 424 }
 425
 426 static void Set8bppPalette( filter_t *p_filter, uint8_t *p_rgb8 )
 427 {
 428     #define CLIP( x ) ( ((x < 0) ? 0 : (x > 255) ? 255 : x) << 8 )
 429
 430     int y,u,v;
 431     int r,g,b;
 432     int i = 0, j = 0;
 433     uint16_t *p_cmap_r = p_filter->p_sys->p_rgb_r;
 434     uint16_t *p_cmap_g = p_filter->p_sys->p_rgb_g;
 435     uint16_t *p_cmap_b = p_filter->p_sys->p_rgb_b;
 436
 437     unsigned char p_lookup[PALETTE_TABLE_SIZE];
 438
 439     /* This loop calculates the intersection of an YUV box and the RGB cube. */
 440     for ( y = 0; y <= 256; y += 16, i += 128 - 81 )
 441     {
 442         for ( u = 0; u <= 256; u += 32 )
 443         {
 444             for ( v = 0; v <= 256; v += 32 )
 445             {
 446                 r = y + ( (V_RED_COEF*(v-128)) >> SHIFT );
 447                 g = y + ( (U_GREEN_COEF*(u-128)
 448                          + V_GREEN_COEF*(v-128)) >> SHIFT );
 449                 b = y + ( (U_BLUE_COEF*(u-128)) >> SHIFT );
 450
 451                 if( r >= 0x00 && g >= 0x00 && b >= 0x00
 452                         && r <= 0xff && g <= 0xff && b <= 0xff )
 453                 {
 454                     /* This one should never happen unless someone
 455                      * fscked up my code */
 456                     if( j == 256 )
 457                     {
 458                         msg_Err( p_filter, "no colors left in palette" );
 459                         break;
 460                     }
 461
 462                     /* Clip the colors */
 463                     p_cmap_r[ j ] = CLIP( r );
 464                     p_cmap_g[ j ] = CLIP( g );
 465                     p_cmap_b[ j ] = CLIP( b );
 466
 467 #if 0
 468             printf("+++Alloc RGB cmap %d (%d, %d, %d)\n", j,
 469                p_cmap_r[ j ] >>8, p_cmap_g[ j ] >>8,
 470                p_cmap_b[ j ] >>8);
 471 #endif
 472
 473                     /* Allocate color */
 474                     p_lookup[ i ] = 1;
 475                     p_rgb8[ i++ ] = j;
 476                     j++;
 477                 }
 478                 else
 479                 {
 480                     p_lookup[ i ] = 0;
 481                     p_rgb8[ i++ ] = 0;
 482                 }
 483             }
 484         }
 485     }
 486
 487     /* The colors have been allocated, we can set the palette */
 488     /* FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME
 489     p_filter->fmt_out.video.pf_setpalette( p_filter, p_cmap_r, p_cmap_g, p_cmap_b );*/
 490
 491 #if 0
 492     /* There will eventually be a way to know which colors
 493      * couldn't be allocated and try to find a replacement */
 494     p_vout->i_white_pixel = 0xff;
 495     p_vout->i_black_pixel = 0x00;
 496     p_vout->i_gray_pixel = 0x44;
 497     p_vout->i_blue_pixel = 0x3b;
 498 #endif
 499
 500     /* This loop allocates colors that got outside the RGB cube */
 501     for ( i = 0, y = 0; y <= 256; y += 16, i += 128 - 81 )
 502     {
 503         for ( u = 0; u <= 256; u += 32 )
 504         {
 505             for ( v = 0; v <= 256; v += 32, i++ )
 506             {
 507                 int u2, v2, dist, mindist = 100000000;
 508
 509                 if( p_lookup[ i ] || y == 0 )
 510                 {
 511                     continue;
 512                 }
 513
 514                 /* Heavy. yeah. */
 515                 for( u2 = 0; u2 <= 256; u2 += 32 )
 516                 {
 517                     for( v2 = 0; v2 <= 256; v2 += 32 )
 518                     {
 519                         j = ((y>>4)<<7) + (u2>>5)*9 + (v2>>5);
 520                         dist = (u-u2)*(u-u2) + (v-v2)*(v-v2);
 521
 522                         /* Find the nearest color */
 523                         if( p_lookup[ j ] && dist < mindist )
 524                         {
 525                             p_rgb8[ i ] = p_rgb8[ j ];
 526                             mindist = dist;
 527                         }
 528
 529                         j -= 128;
 530
 531                         /* Find the nearest color */
 532                         if( p_lookup[ j ] && dist + 128 < mindist )
 533                         {
 534                             p_rgb8[ i ] = p_rgb8[ j ];
 535                             mindist = dist + 128;
 536                         }
 537                     }
 538                 }
 539             }
 540         }
 541     }
 542 }
 543
 544 #endif
 545