git.sesse.net Git - vlc/blob - plugins/yuv/transforms_yuv.h

   1 /*****************************************************************************
   2  * transforms_yuv.h: C specific YUV transformation macros
   3  *****************************************************************************
   4  * Copyright (C) 1999, 2000 VideoLAN
   5  *
   6  * Authors:
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public
  19  * License along with this program; if not, write to the
  20  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  21  * Boston, MA 02111-1307, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * CONVERT_4YUV_PIXELS: dither 4 pixels in 8 bpp
  26  *****************************************************************************
  27  * These macros dither 4 pixels in 8 bpp
  28  *****************************************************************************/
  29 #define CONVERT_4YUV_PIXELS( CHROMA )                                         \
  30     *p_pic++ = p_lookup[                                                      \
  31         (((*p_y++ + dither10[i_real_y]) >> 4) << 7)                           \
  32       + ((*p_u + dither20[i_real_y]) >> 5) * 9                                \
  33       + ((*p_v + dither20[i_real_y]) >> 5) ];                                 \
  34     *p_pic++ = p_lookup[                                                      \
  35         (((*p_y++ + dither11[i_real_y]) >> 4) << 7)                           \
  36       + ((*p_u++ + dither21[i_real_y]) >> 5) * 9                              \
  37       + ((*p_v++ + dither21[i_real_y]) >> 5) ];                               \
  38     *p_pic++ = p_lookup[                                                      \
  39         (((*p_y++ + dither12[i_real_y]) >> 4) << 7)                           \
  40       + ((*p_u + dither22[i_real_y]) >> 5) * 9                                \
  41       + ((*p_v + dither22[i_real_y]) >> 5) ];                                 \
  42     *p_pic++ = p_lookup[                                                      \
  43         (((*p_y++ + dither13[i_real_y]) >> 4) << 7)                           \
  44       + ((*p_u++ + dither23[i_real_y]) >> 5) * 9                              \
  45       + ((*p_v++ + dither23[i_real_y]) >> 5) ];                               \
  46
  47 /*****************************************************************************
  48  * CONVERT_4YUV_PIXELS_SCALE: dither and scale 4 pixels in 8 bpp
  49  *****************************************************************************
  50  * These macros dither 4 pixels in 8 bpp, with horizontal scaling
  51  *****************************************************************************/
  52 #define CONVERT_4YUV_PIXELS_SCALE( CHROMA )                                   \
  53     *p_pic++ = p_lookup[                                                      \
  54         ( ((*p_y + dither10[i_real_y]) >> 4) << 7)                            \
  55         + ((*p_u + dither20[i_real_y]) >> 5) * 9                              \
  56         + ((*p_v + dither20[i_real_y]) >> 5) ];                               \
  57     p_y += *p_offset++;                                                       \
  58     p_u += *p_offset;                                                         \
  59     p_v += *p_offset++;                                                       \
  60     *p_pic++ = p_lookup[                                                      \
  61         ( ((*p_y + dither11[i_real_y]) >> 4) << 7)                            \
  62         + ((*p_u + dither21[i_real_y]) >> 5) * 9                              \
  63         + ((*p_v + dither21[i_real_y]) >> 5) ];                               \
  64     p_y += *p_offset++;                                                       \
  65     p_u += *p_offset;                                                         \
  66     p_v += *p_offset++;                                                       \
  67     *p_pic++ = p_lookup[                                                      \
  68         ( ((*p_y + dither12[i_real_y]) >> 4) << 7)                            \
  69         + ((*p_u + dither22[i_real_y]) >> 5) * 9                              \
  70         + ((*p_v + dither22[i_real_y]) >> 5) ];                               \
  71     p_y += *p_offset++;                                                       \
  72     p_u += *p_offset;                                                         \
  73     p_v += *p_offset++;                                                       \
  74     *p_pic++ = p_lookup[                                                      \
  75         ( ((*p_y + dither13[i_real_y]) >> 4) << 7)                            \
  76         + ((*p_u + dither23[i_real_y]) >> 5) * 9                              \
  77         + ((*p_v + dither23[i_real_y]) >> 5) ];                               \
  78     p_y += *p_offset++;                                                       \
  79     p_u += *p_offset;                                                         \
  80     p_v += *p_offset++;                                                       \
  81
  82 /*****************************************************************************
  83  * SCALE_WIDTH_DITHER: scale a line horizontally for dithered 8 bpp
  84  *****************************************************************************
  85  * This macro scales a line using an offset array.
  86  *****************************************************************************/
  87 #define SCALE_WIDTH_DITHER( CHROMA )                                          \
  88     if( b_horizontal_scaling )                                                \
  89     {                                                                         \
  90         /* Horizontal scaling - we can't use a buffer due to dithering */     \
  91         p_offset = p_offset_start;                                            \
  92         for( i_x = i_pic_width / 16; i_x--; )                                 \
  93         {                                                                     \
  94             CONVERT_4YUV_PIXELS_SCALE( CHROMA )                               \
  95             CONVERT_4YUV_PIXELS_SCALE( CHROMA )                               \
  96             CONVERT_4YUV_PIXELS_SCALE( CHROMA )                               \
  97             CONVERT_4YUV_PIXELS_SCALE( CHROMA )                               \
  98         }                                                                     \
  99     }                                                                         \
 100     else                                                                      \
 101     {                                                                         \
 102         for( i_x = i_width / 16; i_x--;  )                                    \
 103         {                                                                     \
 104             CONVERT_4YUV_PIXELS( CHROMA )                                     \
 105             CONVERT_4YUV_PIXELS( CHROMA )                                     \
 106             CONVERT_4YUV_PIXELS( CHROMA )                                     \
 107             CONVERT_4YUV_PIXELS( CHROMA )                                     \
 108         }                                                                     \
 109     }                                                                         \
 110     /* Increment of picture pointer to end of line is still needed */         \
 111     p_pic += i_pic_line_width;                                                \
 112                                                                               \
 113     /* Increment the Y coordinate in the matrix, modulo 4 */                  \
 114     i_real_y = (i_real_y + 1) & 0x3;                                          \
 115
 116 /*****************************************************************************
 117  * SCALE_HEIGHT_DITHER: handle vertical scaling for dithered 8 bpp
 118  *****************************************************************************
 119  * This macro handles vertical scaling for a picture. CHROMA may be 420,
 120  * 422 or 444 for RGB conversion, or 400 for gray conversion.
 121  *****************************************************************************/
 122 #define SCALE_HEIGHT_DITHER( CHROMA )                                         \
 123                                                                               \
 124     /* If line is odd, rewind 4:2:0 U and V samples */                        \
 125     if( ((CHROMA == 420) || (CHROMA == 422)) && !(i_y & 0x1) )                \
 126     {                                                                         \
 127         p_u -= i_chroma_width;                                                \
 128         p_v -= i_chroma_width;                                                \
 129     }                                                                         \
 130                                                                               \
 131     /*                                                                        \
 132      * Handle vertical scaling. The current line can be copied or next one    \
 133      * can be ignored.                                                        \
 134      */                                                                       \
 135                                                                               \
 136     switch( i_vertical_scaling )                                              \
 137     {                                                                         \
 138     case -1:                             /* vertical scaling factor is < 1 */ \
 139         while( (i_scale_count -= i_pic_height) > 0 )                          \
 140         {                                                                     \
 141             /* Height reduction: skip next source line */                     \
 142             p_y += i_width;                                                   \
 143             i_y++;                                                            \
 144             if( (CHROMA == 420) || (CHROMA == 422) )                          \
 145             {                                                                 \
 146                 if( i_y & 0x1 )                                               \
 147                 {                                                             \
 148                     p_u += i_chroma_width;                                    \
 149                     p_v += i_chroma_width;                                    \
 150                 }                                                             \
 151             }                                                                 \
 152             else if( CHROMA == 444 )                                          \
 153             {                                                                 \
 154                 p_u += i_width;                                               \
 155                 p_v += i_width;                                               \
 156             }                                                                 \
 157         }                                                                     \
 158         i_scale_count += i_height;                                            \
 159         break;                                                                \
 160     case 1:                              /* vertical scaling factor is > 1 */ \
 161         while( (i_scale_count -= i_height) > 0 )                              \
 162         {                                                                     \
 163             p_y -= i_width;                                                   \
 164             p_u -= i_chroma_width;                                            \
 165             p_v -= i_chroma_width;                                            \
 166             SCALE_WIDTH_DITHER( CHROMA );                                     \
 167         }                                                                     \
 168         i_scale_count += i_pic_height;                                        \
 169         break;                                                                \
 170     }                                                                         \
 171