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  * $Id: transforms_yuv.h,v 1.2 2001/03/21 13:42:34 sam Exp $
   6  *
   7  * Authors: Samuel Hocevar <sam@zoy.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public
  20  * License along with this program; if not, write to the
  21  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  22  * Boston, MA 02111-1307, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * CONVERT_4YUV_PIXELS: dither 4 pixels in 8 bpp
  27  *****************************************************************************
  28  * These macros dither 4 pixels in 8 bpp
  29  *****************************************************************************/
  30 #define CONVERT_4YUV_PIXELS( CHROMA )                                         \
  31     *p_pic++ = p_lookup[                                                      \
  32         (((*p_y++ + dither10[i_real_y]) >> 4) << 7)                           \
  33       + ((*p_u + dither20[i_real_y]) >> 5) * 9                                \
  34       + ((*p_v + dither20[i_real_y]) >> 5) ];                                 \
  35     *p_pic++ = p_lookup[                                                      \
  36         (((*p_y++ + dither11[i_real_y]) >> 4) << 7)                           \
  37       + ((*p_u++ + dither21[i_real_y]) >> 5) * 9                              \
  38       + ((*p_v++ + dither21[i_real_y]) >> 5) ];                               \
  39     *p_pic++ = p_lookup[                                                      \
  40         (((*p_y++ + dither12[i_real_y]) >> 4) << 7)                           \
  41       + ((*p_u + dither22[i_real_y]) >> 5) * 9                                \
  42       + ((*p_v + dither22[i_real_y]) >> 5) ];                                 \
  43     *p_pic++ = p_lookup[                                                      \
  44         (((*p_y++ + dither13[i_real_y]) >> 4) << 7)                           \
  45       + ((*p_u++ + dither23[i_real_y]) >> 5) * 9                              \
  46       + ((*p_v++ + dither23[i_real_y]) >> 5) ];                               \
  47
  48 /*****************************************************************************
  49  * CONVERT_4YUV_PIXELS_SCALE: dither and scale 4 pixels in 8 bpp
  50  *****************************************************************************
  51  * These macros dither 4 pixels in 8 bpp, with horizontal scaling
  52  *****************************************************************************/
  53 #define CONVERT_4YUV_PIXELS_SCALE( CHROMA )                                   \
  54     *p_pic++ = p_lookup[                                                      \
  55         ( ((*p_y + dither10[i_real_y]) >> 4) << 7)                            \
  56         + ((*p_u + dither20[i_real_y]) >> 5) * 9                              \
  57         + ((*p_v + dither20[i_real_y]) >> 5) ];                               \
  58     p_y += *p_offset++;                                                       \
  59     p_u += *p_offset;                                                         \
  60     p_v += *p_offset++;                                                       \
  61     *p_pic++ = p_lookup[                                                      \
  62         ( ((*p_y + dither11[i_real_y]) >> 4) << 7)                            \
  63         + ((*p_u + dither21[i_real_y]) >> 5) * 9                              \
  64         + ((*p_v + dither21[i_real_y]) >> 5) ];                               \
  65     p_y += *p_offset++;                                                       \
  66     p_u += *p_offset;                                                         \
  67     p_v += *p_offset++;                                                       \
  68     *p_pic++ = p_lookup[                                                      \
  69         ( ((*p_y + dither12[i_real_y]) >> 4) << 7)                            \
  70         + ((*p_u + dither22[i_real_y]) >> 5) * 9                              \
  71         + ((*p_v + dither22[i_real_y]) >> 5) ];                               \
  72     p_y += *p_offset++;                                                       \
  73     p_u += *p_offset;                                                         \
  74     p_v += *p_offset++;                                                       \
  75     *p_pic++ = p_lookup[                                                      \
  76         ( ((*p_y + dither13[i_real_y]) >> 4) << 7)                            \
  77         + ((*p_u + dither23[i_real_y]) >> 5) * 9                              \
  78         + ((*p_v + dither23[i_real_y]) >> 5) ];                               \
  79     p_y += *p_offset++;                                                       \
  80     p_u += *p_offset;                                                         \
  81     p_v += *p_offset++;                                                       \
  82
  83 /*****************************************************************************
  84  * SCALE_WIDTH_DITHER: scale a line horizontally for dithered 8 bpp
  85  *****************************************************************************
  86  * This macro scales a line using an offset array.
  87  *****************************************************************************/
  88 #define SCALE_WIDTH_DITHER( CHROMA )                                          \
  89     if( b_horizontal_scaling )                                                \
  90     {                                                                         \
  91         /* Horizontal scaling - we can't use a buffer due to dithering */     \
  92         p_offset = p_offset_start;                                            \
  93         for( i_x = i_pic_width / 16; i_x--; )                                 \
  94         {                                                                     \
  95             CONVERT_4YUV_PIXELS_SCALE( CHROMA )                               \
  96             CONVERT_4YUV_PIXELS_SCALE( CHROMA )                               \
  97             CONVERT_4YUV_PIXELS_SCALE( CHROMA )                               \
  98             CONVERT_4YUV_PIXELS_SCALE( CHROMA )                               \
  99         }                                                                     \
 100     }                                                                         \
 101     else                                                                      \
 102     {                                                                         \
 103         for( i_x = i_width / 16; i_x--;  )                                    \
 104         {                                                                     \
 105             CONVERT_4YUV_PIXELS( CHROMA )                                     \
 106             CONVERT_4YUV_PIXELS( CHROMA )                                     \
 107             CONVERT_4YUV_PIXELS( CHROMA )                                     \
 108             CONVERT_4YUV_PIXELS( CHROMA )                                     \
 109         }                                                                     \
 110     }                                                                         \
 111     /* Increment of picture pointer to end of line is still needed */         \
 112     p_pic += i_pic_line_width;                                                \
 113                                                                               \
 114     /* Increment the Y coordinate in the matrix, modulo 4 */                  \
 115     i_real_y = (i_real_y + 1) & 0x3;                                          \
 116
 117 /*****************************************************************************
 118  * SCALE_HEIGHT_DITHER: handle vertical scaling for dithered 8 bpp
 119  *****************************************************************************
 120  * This macro handles vertical scaling for a picture. CHROMA may be 420,
 121  * 422 or 444 for RGB conversion, or 400 for gray conversion.
 122  *****************************************************************************/
 123 #define SCALE_HEIGHT_DITHER( CHROMA )                                         \
 124                                                                               \
 125     /* If line is odd, rewind 4:2:0 U and V samples */                        \
 126     if( ((CHROMA == 420) || (CHROMA == 422)) && !(i_y & 0x1) )                \
 127     {                                                                         \
 128         p_u -= i_chroma_width;                                                \
 129         p_v -= i_chroma_width;                                                \
 130     }                                                                         \
 131                                                                               \
 132     /*                                                                        \
 133      * Handle vertical scaling. The current line can be copied or next one    \
 134      * can be ignored.                                                        \
 135      */                                                                       \
 136                                                                               \
 137     switch( i_vertical_scaling )                                              \
 138     {                                                                         \
 139     case -1:                             /* vertical scaling factor is < 1 */ \
 140         while( (i_scale_count -= i_pic_height) > 0 )                          \
 141         {                                                                     \
 142             /* Height reduction: skip next source line */                     \
 143             p_y += i_width;                                                   \
 144             i_y++;                                                            \
 145             if( (CHROMA == 420) || (CHROMA == 422) )                          \
 146             {                                                                 \
 147                 if( i_y & 0x1 )                                               \
 148                 {                                                             \
 149                     p_u += i_chroma_width;                                    \
 150                     p_v += i_chroma_width;                                    \
 151                 }                                                             \
 152             }                                                                 \
 153             else if( CHROMA == 444 )                                          \
 154             {                                                                 \
 155                 p_u += i_width;                                               \
 156                 p_v += i_width;                                               \
 157             }                                                                 \
 158         }                                                                     \
 159         i_scale_count += i_height;                                            \
 160         break;                                                                \
 161     case 1:                              /* vertical scaling factor is > 1 */ \
 162         while( (i_scale_count -= i_height) > 0 )                              \
 163         {                                                                     \
 164             p_y -= i_width;                                                   \
 165             p_u -= i_chroma_width;                                            \
 166             p_v -= i_chroma_width;                                            \
 167             SCALE_WIDTH_DITHER( CHROMA );                                     \
 168         }                                                                     \
 169         i_scale_count += i_pic_height;                                        \
 170         break;                                                                \
 171     }                                                                         \
 172