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 #elif defined (MODULE_NAME_IS_i420_rgb_mmx)
  88     set_description( N_( "MMX I420,IYUV,YV12 to "
  89                         "RV15,RV16,RV24,RV32 conversions") )
  90     set_capability( "video filter2", 100 )
  91 #elif defined (MODULE_NAME_IS_i420_rgb_sse2)
  92     set_description( N_( "SSE2 I420,IYUV,YV12 to "
  93                         "RV15,RV16,RV24,RV32 conversions") )
  94     set_capability( "video filter2", 120 )
  95     add_requirement( SSE2 )
  96 #endif
  97     set_callbacks( Activate, Deactivate )
  98 vlc_module_end ()
  99
 100 /*****************************************************************************
 101  * Activate: allocate a chroma function
 102  *****************************************************************************
 103  * This function allocates and initializes a chroma function
 104  *****************************************************************************/
 105 static int Activate( vlc_object_t *p_this )
 106 {
 107     filter_t *p_filter = (filter_t *)p_this;
 108 #if defined (MODULE_NAME_IS_i420_rgb)
 109     size_t i_tables_size;
 110 #endif
 111
 112     if( p_filter->fmt_out.video.i_width & 1
 113      || p_filter->fmt_out.video.i_height & 1 )
 114     {
 115         return VLC_EGENERIC;
 116     }
 117
 118     switch( p_filter->fmt_in.video.i_chroma )
 119     {
 120         case VLC_CODEC_YV12:
 121         case VLC_CODEC_I420:
 122             switch( p_filter->fmt_out.video.i_chroma )
 123             {
 124 #if defined (MODULE_NAME_IS_i420_rgb)
 125                 case VLC_CODEC_RGB8:
 126                     p_filter->pf_video_filter = I420_RGB8_Filter;
 127                     break;
 128 #endif
 129                 case VLC_CODEC_RGB15:
 130                 case VLC_CODEC_RGB16:
 131 #if ! defined (MODULE_NAME_IS_i420_rgb)
 132                     /* If we don't have support for the bitmasks, bail out */
 133                     if( ( p_filter->fmt_out.video.i_rmask == 0x7c00
 134                        && p_filter->fmt_out.video.i_gmask == 0x03e0
 135                        && p_filter->fmt_out.video.i_bmask == 0x001f ) )
 136                     {
 137                         /* R5G5B6 pixel format */
 138                         msg_Dbg(p_this, "RGB pixel format is R5G5B5");
 139                         p_filter->pf_video_filter = I420_R5G5B5_Filter;
 140                     }
 141                     else if( ( p_filter->fmt_out.video.i_rmask == 0xf800
 142                             && p_filter->fmt_out.video.i_gmask == 0x07e0
 143                             && p_filter->fmt_out.video.i_bmask == 0x001f ) )
 144                     {
 145                         /* R5G6B5 pixel format */
 146                         msg_Dbg(p_this, "RGB pixel format is R5G6B5");
 147                         p_filter->pf_video_filter = I420_R5G6B5_Filter;
 148                     }
 149                     else
 150                         return VLC_EGENERIC;
 151 #else
 152                     // generic C chroma converter */
 153                     p_filter->pf_video_filter = I420_RGB16_Filter;
 154 #endif
 155                     break;
 156
 157 #if 0
 158                 /* Hmmm, is there only X11 using 32bits per pixel for RV24 ? */
 159                 case VLC_CODEC_RGB24:
 160 #endif
 161
 162                 case VLC_CODEC_RGB32:
 163 #if ! defined (MODULE_NAME_IS_i420_rgb)
 164                     /* If we don't have support for the bitmasks, bail out */
 165                     if( p_filter->fmt_out.video.i_rmask == 0x00ff0000
 166                      && p_filter->fmt_out.video.i_gmask == 0x0000ff00
 167                      && p_filter->fmt_out.video.i_bmask == 0x000000ff )
 168                     {
 169                         /* A8R8G8B8 pixel format */
 170                         msg_Dbg(p_this, "RGB pixel format is A8R8G8B8");
 171                         p_filter->pf_video_filter = I420_A8R8G8B8_Filter;
 172                     }
 173                     else if( p_filter->fmt_out.video.i_rmask == 0xff000000
 174                           && p_filter->fmt_out.video.i_gmask == 0x00ff0000
 175                           && p_filter->fmt_out.video.i_bmask == 0x0000ff00 )
 176                     {
 177                         /* R8G8B8A8 pixel format */
 178                         msg_Dbg(p_this, "RGB pixel format is R8G8B8A8");
 179                         p_filter->pf_video_filter = I420_R8G8B8A8_Filter;
 180                     }
 181                     else if( p_filter->fmt_out.video.i_rmask == 0x0000ff00
 182                           && p_filter->fmt_out.video.i_gmask == 0x00ff0000
 183                           && p_filter->fmt_out.video.i_bmask == 0xff000000 )
 184                     {
 185                         /* B8G8R8A8 pixel format */
 186                         msg_Dbg(p_this, "RGB pixel format is B8G8R8A8");
 187                         p_filter->pf_video_filter = I420_B8G8R8A8_Filter;
 188                     }
 189                     else if( p_filter->fmt_out.video.i_rmask == 0x000000ff
 190                           && p_filter->fmt_out.video.i_gmask == 0x0000ff00
 191                           && p_filter->fmt_out.video.i_bmask == 0x00ff0000 )
 192                     {
 193                         /* A8B8G8R8 pixel format */
 194                         msg_Dbg(p_this, "RGB pixel format is A8B8G8R8");
 195                         p_filter->pf_video_filter = I420_A8B8G8R8_Filter;
 196                     }
 197                     else
 198                         return VLC_EGENERIC;
 199 #else
 200                     /* generic C chroma converter */
 201                     p_filter->pf_video_filter = I420_RGB32_Filter;
 202 #endif
 203                     break;
 204
 205                 default:
 206                     return VLC_EGENERIC;
 207             }
 208             break;
 209
 210         default:
 211             return VLC_EGENERIC;
 212     }
 213
 214     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 215     if( p_filter->p_sys == NULL )
 216     {
 217         return VLC_EGENERIC;
 218     }
 219
 220     switch( p_filter->fmt_out.video.i_chroma )
 221     {
 222 #if defined (MODULE_NAME_IS_i420_rgb)
 223         case VLC_CODEC_RGB8:
 224             p_filter->p_sys->p_buffer = malloc( VOUT_MAX_WIDTH );
 225             break;
 226 #endif
 227
 228         case VLC_CODEC_RGB15:
 229         case VLC_CODEC_RGB16:
 230             p_filter->p_sys->p_buffer = malloc( VOUT_MAX_WIDTH * 2 );
 231             break;
 232
 233         case VLC_CODEC_RGB24:
 234         case VLC_CODEC_RGB32:
 235             p_filter->p_sys->p_buffer = malloc( VOUT_MAX_WIDTH * 4 );
 236             break;
 237
 238         default:
 239             p_filter->p_sys->p_buffer = NULL;
 240             break;
 241     }
 242
 243     if( p_filter->p_sys->p_buffer == NULL )
 244     {
 245         free( p_filter->p_sys );
 246         return VLC_EGENERIC;
 247     }
 248
 249     p_filter->p_sys->p_offset = malloc( p_filter->fmt_out.video.i_width
 250                     * ( ( p_filter->fmt_out.video.i_chroma
 251                            == VLC_CODEC_RGB8 ) ? 2 : 1 )
 252                     * sizeof( int ) );
 253     if( p_filter->p_sys->p_offset == NULL )
 254     {
 255         free( p_filter->p_sys->p_buffer );
 256         free( p_filter->p_sys );
 257         return VLC_EGENERIC;
 258     }
 259
 260 #if defined (MODULE_NAME_IS_i420_rgb)
 261     switch( p_filter->fmt_out.video.i_chroma )
 262     {
 263     case VLC_CODEC_RGB8:
 264         i_tables_size = sizeof( uint8_t ) * PALETTE_TABLE_SIZE;
 265         break;
 266     case VLC_CODEC_RGB15:
 267     case VLC_CODEC_RGB16:
 268         i_tables_size = sizeof( uint16_t ) * RGB_TABLE_SIZE;
 269         break;
 270     default: /* RV24, RV32 */
 271         i_tables_size = sizeof( uint32_t ) * RGB_TABLE_SIZE;
 272         break;
 273     }
 274
 275     p_filter->p_sys->p_base = malloc( i_tables_size );
 276     if( p_filter->p_sys->p_base == NULL )
 277     {
 278         free( p_filter->p_sys->p_offset );
 279         free( p_filter->p_sys->p_buffer );
 280         free( p_filter->p_sys );
 281         return -1;
 282     }
 283
 284     SetYUV( p_filter );
 285 #endif
 286
 287     return 0;
 288 }
 289
 290 /*****************************************************************************
 291  * Deactivate: free the chroma function
 292  *****************************************************************************
 293  * This function frees the previously allocated chroma function
 294  *****************************************************************************/
 295 static void Deactivate( vlc_object_t *p_this )
 296 {
 297     filter_t *p_filter = (filter_t *)p_this;
 298
 299 #if defined (MODULE_NAME_IS_i420_rgb)
 300     free( p_filter->p_sys->p_base );
 301 #endif
 302     free( p_filter->p_sys->p_offset );
 303     free( p_filter->p_sys->p_buffer );
 304     free( p_filter->p_sys );
 305 }
 306
 307 #if defined (MODULE_NAME_IS_i420_rgb)
 308 VIDEO_FILTER_WRAPPER( I420_RGB8 )
 309 VIDEO_FILTER_WRAPPER( I420_RGB16 )
 310 //VIDEO_FILTER_WRAPPER( I420_RGB16_dither )
 311 VIDEO_FILTER_WRAPPER( I420_RGB32 )
 312 #else
 313 VIDEO_FILTER_WRAPPER( I420_R5G5B5 )
 314 VIDEO_FILTER_WRAPPER( I420_R5G6B5 )
 315 VIDEO_FILTER_WRAPPER( I420_A8R8G8B8 )
 316 VIDEO_FILTER_WRAPPER( I420_R8G8B8A8 )
 317 VIDEO_FILTER_WRAPPER( I420_B8G8R8A8 )
 318 VIDEO_FILTER_WRAPPER( I420_A8B8G8R8 )
 319 #endif
 320
 321 #if defined (MODULE_NAME_IS_i420_rgb)
 322 /*****************************************************************************
 323  * SetGammaTable: return intensity table transformed by gamma curve.
 324  *****************************************************************************
 325  * pi_table is a table of 256 entries from 0 to 255.
 326  *****************************************************************************/
 327 static void SetGammaTable( int *pi_table, double f_gamma )
 328 {
 329     int i_y;                                               /* base intensity */
 330
 331     /* Use exp(gamma) instead of gamma */
 332     f_gamma = exp( f_gamma );
 333
 334     /* Build gamma table */
 335     for( i_y = 0; i_y < 256; i_y++ )
 336     {
 337         pi_table[ i_y ] = (int)( pow( (double)i_y / 256, f_gamma ) * 256 );
 338     }
 339 }
 340
 341 /*****************************************************************************
 342  * SetYUV: compute tables and set function pointers
 343  *****************************************************************************/
 344 static void SetYUV( filter_t *p_filter )
 345 {
 346     int          pi_gamma[256];                               /* gamma table */
 347     volatile int i_index;                                 /* index in tables */
 348                    /* We use volatile here to work around a strange gcc-3.3.4
 349                     * optimization bug */
 350
 351     /* Build gamma table */
 352     SetGammaTable( pi_gamma, 0 ); //p_filter/*FIXME wasn't used anywhere anyway*/->f_gamma );
 353
 354     /*
 355      * Set pointers and build YUV tables
 356      */
 357
 358     /* Color: build red, green and blue tables */
 359     switch( p_filter->fmt_out.video.i_chroma )
 360     {
 361     case VLC_CODEC_RGB8:
 362         p_filter->p_sys->p_rgb8 = (uint8_t *)p_filter->p_sys->p_base;
 363         Set8bppPalette( p_filter, p_filter->p_sys->p_rgb8 );
 364         break;
 365
 366     case VLC_CODEC_RGB15:
 367     case VLC_CODEC_RGB16:
 368         p_filter->p_sys->p_rgb16 = (uint16_t *)p_filter->p_sys->p_base;
 369         for( i_index = 0; i_index < RED_MARGIN; i_index++ )
 370         {
 371             p_filter->p_sys->p_rgb16[RED_OFFSET - RED_MARGIN + i_index] = RGB2PIXEL( p_filter, pi_gamma[0], 0, 0 );
 372             p_filter->p_sys->p_rgb16[RED_OFFSET + 256 + i_index] =        RGB2PIXEL( p_filter, pi_gamma[255], 0, 0 );
 373         }
 374         for( i_index = 0; i_index < GREEN_MARGIN; i_index++ )
 375         {
 376             p_filter->p_sys->p_rgb16[GREEN_OFFSET - GREEN_MARGIN + i_index] = RGB2PIXEL( p_filter, 0, pi_gamma[0], 0 );
 377             p_filter->p_sys->p_rgb16[GREEN_OFFSET + 256 + i_index] =          RGB2PIXEL( p_filter, 0, pi_gamma[255], 0 );
 378         }
 379         for( i_index = 0; i_index < BLUE_MARGIN; i_index++ )
 380         {
 381             p_filter->p_sys->p_rgb16[BLUE_OFFSET - BLUE_MARGIN + i_index] = RGB2PIXEL( p_filter, 0, 0, pi_gamma[0] );
 382             p_filter->p_sys->p_rgb16[BLUE_OFFSET + BLUE_MARGIN + i_index] = RGB2PIXEL( p_filter, 0, 0, pi_gamma[255] );
 383         }
 384         for( i_index = 0; i_index < 256; i_index++ )
 385         {
 386             p_filter->p_sys->p_rgb16[RED_OFFSET + i_index] =   RGB2PIXEL( p_filter, pi_gamma[ i_index ], 0, 0 );
 387             p_filter->p_sys->p_rgb16[GREEN_OFFSET + i_index] = RGB2PIXEL( p_filter, 0, pi_gamma[ i_index ], 0 );
 388             p_filter->p_sys->p_rgb16[BLUE_OFFSET + i_index] =  RGB2PIXEL( p_filter, 0, 0, pi_gamma[ i_index ] );
 389         }
 390         break;
 391
 392     case VLC_CODEC_RGB24:
 393     case VLC_CODEC_RGB32:
 394         p_filter->p_sys->p_rgb32 = (uint32_t *)p_filter->p_sys->p_base;
 395         for( i_index = 0; i_index < RED_MARGIN; i_index++ )
 396         {
 397             p_filter->p_sys->p_rgb32[RED_OFFSET - RED_MARGIN + i_index] = RGB2PIXEL( p_filter, pi_gamma[0], 0, 0 );
 398             p_filter->p_sys->p_rgb32[RED_OFFSET + 256 + i_index] =        RGB2PIXEL( p_filter, pi_gamma[255], 0, 0 );
 399         }
 400         for( i_index = 0; i_index < GREEN_MARGIN; i_index++ )
 401         {
 402             p_filter->p_sys->p_rgb32[GREEN_OFFSET - GREEN_MARGIN + i_index] = RGB2PIXEL( p_filter, 0, pi_gamma[0], 0 );
 403             p_filter->p_sys->p_rgb32[GREEN_OFFSET + 256 + i_index] =          RGB2PIXEL( p_filter, 0, pi_gamma[255], 0 );
 404         }
 405         for( i_index = 0; i_index < BLUE_MARGIN; i_index++ )
 406         {
 407             p_filter->p_sys->p_rgb32[BLUE_OFFSET - BLUE_MARGIN + i_index] = RGB2PIXEL( p_filter, 0, 0, pi_gamma[0] );
 408             p_filter->p_sys->p_rgb32[BLUE_OFFSET + BLUE_MARGIN + i_index] = RGB2PIXEL( p_filter, 0, 0, pi_gamma[255] );
 409         }
 410         for( i_index = 0; i_index < 256; i_index++ )
 411         {
 412             p_filter->p_sys->p_rgb32[RED_OFFSET + i_index] =   RGB2PIXEL( p_filter, pi_gamma[ i_index ], 0, 0 );
 413             p_filter->p_sys->p_rgb32[GREEN_OFFSET + i_index] = RGB2PIXEL( p_filter, 0, pi_gamma[ i_index ], 0 );
 414             p_filter->p_sys->p_rgb32[BLUE_OFFSET + i_index] =  RGB2PIXEL( p_filter, 0, 0, pi_gamma[ i_index ] );
 415         }
 416         break;
 417     }
 418 }
 419
 420 static void Set8bppPalette( filter_t *p_filter, uint8_t *p_rgb8 )
 421 {
 422     #define CLIP( x ) ( ((x < 0) ? 0 : (x > 255) ? 255 : x) << 8 )
 423
 424     int y,u,v;
 425     int r,g,b;
 426     int i = 0, j = 0;
 427     uint16_t *p_cmap_r = p_filter->p_sys->p_rgb_r;
 428     uint16_t *p_cmap_g = p_filter->p_sys->p_rgb_g;
 429     uint16_t *p_cmap_b = p_filter->p_sys->p_rgb_b;
 430
 431     unsigned char p_lookup[PALETTE_TABLE_SIZE];
 432
 433     /* This loop calculates the intersection of an YUV box and the RGB cube. */
 434     for ( y = 0; y <= 256; y += 16, i += 128 - 81 )
 435     {
 436         for ( u = 0; u <= 256; u += 32 )
 437         {
 438             for ( v = 0; v <= 256; v += 32 )
 439             {
 440                 r = y + ( (V_RED_COEF*(v-128)) >> SHIFT );
 441                 g = y + ( (U_GREEN_COEF*(u-128)
 442                          + V_GREEN_COEF*(v-128)) >> SHIFT );
 443                 b = y + ( (U_BLUE_COEF*(u-128)) >> SHIFT );
 444
 445                 if( r >= 0x00 && g >= 0x00 && b >= 0x00
 446                         && r <= 0xff && g <= 0xff && b <= 0xff )
 447                 {
 448                     /* This one should never happen unless someone
 449                      * fscked up my code */
 450                     if( j == 256 )
 451                     {
 452                         msg_Err( p_filter, "no colors left in palette" );
 453                         break;
 454                     }
 455
 456                     /* Clip the colors */
 457                     p_cmap_r[ j ] = CLIP( r );
 458                     p_cmap_g[ j ] = CLIP( g );
 459                     p_cmap_b[ j ] = CLIP( b );
 460
 461 #if 0
 462             printf("+++Alloc RGB cmap %d (%d, %d, %d)\n", j,
 463                p_cmap_r[ j ] >>8, p_cmap_g[ j ] >>8,
 464                p_cmap_b[ j ] >>8);
 465 #endif
 466
 467                     /* Allocate color */
 468                     p_lookup[ i ] = 1;
 469                     p_rgb8[ i++ ] = j;
 470                     j++;
 471                 }
 472                 else
 473                 {
 474                     p_lookup[ i ] = 0;
 475                     p_rgb8[ i++ ] = 0;
 476                 }
 477             }
 478         }
 479     }
 480
 481     /* The colors have been allocated, we can set the palette */
 482     /* FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME
 483     p_filter->fmt_out.video.pf_setpalette( p_filter, p_cmap_r, p_cmap_g, p_cmap_b );*/
 484
 485 #if 0
 486     /* There will eventually be a way to know which colors
 487      * couldn't be allocated and try to find a replacement */
 488     p_vout->i_white_pixel = 0xff;
 489     p_vout->i_black_pixel = 0x00;
 490     p_vout->i_gray_pixel = 0x44;
 491     p_vout->i_blue_pixel = 0x3b;
 492 #endif
 493
 494     /* This loop allocates colors that got outside the RGB cube */
 495     for ( i = 0, y = 0; y <= 256; y += 16, i += 128 - 81 )
 496     {
 497         for ( u = 0; u <= 256; u += 32 )
 498         {
 499             for ( v = 0; v <= 256; v += 32, i++ )
 500             {
 501                 int u2, v2, dist, mindist = 100000000;
 502
 503                 if( p_lookup[ i ] || y == 0 )
 504                 {
 505                     continue;
 506                 }
 507
 508                 /* Heavy. yeah. */
 509                 for( u2 = 0; u2 <= 256; u2 += 32 )
 510                 {
 511                     for( v2 = 0; v2 <= 256; v2 += 32 )
 512                     {
 513                         j = ((y>>4)<<7) + (u2>>5)*9 + (v2>>5);
 514                         dist = (u-u2)*(u-u2) + (v-v2)*(v-v2);
 515
 516                         /* Find the nearest color */
 517                         if( p_lookup[ j ] && dist < mindist )
 518                         {
 519                             p_rgb8[ i ] = p_rgb8[ j ];
 520                             mindist = dist;
 521                         }
 522
 523                         j -= 128;
 524
 525                         /* Find the nearest color */
 526                         if( p_lookup[ j ] && dist + 128 < mindist )
 527                         {
 528                             p_rgb8[ i ] = p_rgb8[ j ];
 529                             mindist = dist + 128;
 530                         }
 531                     }
 532                 }
 533             }
 534         }
 535     }
 536 }
 537
 538 #endif
 539