apps/plugins/mpegplayer/idct.c

   1 /*
   2  * idct.c
   3  * Copyright (C) 2000-2003 Michel Lespinasse <walken@zoy.org>
   4  * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
   5  *
   6  * This file is part of mpeg2dec, a free MPEG-2 video stream decoder.
   7  * See http://libmpeg2.sourceforge.net/ for updates.
   8  *
   9  * mpeg2dec 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  * mpeg2dec 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
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  *
  23  * $Id$
  24  * libmpeg2 sync history:
  25  * 2008-07-01 - CVS revision 1.36
  26  */
  27
  28 #include "plugin.h"
  29
  30 #include "mpeg2dec_config.h"
  31
  32 #include "mpeg2.h"
  33 #include "attributes.h"
  34 #include "mpeg2_internal.h"
  35
  36 #if defined(CPU_COLDFIRE) || defined (CPU_ARM)
  37 #define IDCT_ASM
  38 #endif
  39
  40 #ifndef IDCT_ASM
  41
  42 #define W1 2841 /* 2048 * sqrt (2) * cos (1 * pi / 16) */
  43 #define W2 2676 /* 2048 * sqrt (2) * cos (2 * pi / 16) */
  44 #define W3 2408 /* 2048 * sqrt (2) * cos (3 * pi / 16) */
  45 #define W5 1609 /* 2048 * sqrt (2) * cos (5 * pi / 16) */
  46 #define W6 1108 /* 2048 * sqrt (2) * cos (6 * pi / 16) */
  47 #define W7 565  /* 2048 * sqrt (2) * cos (7 * pi / 16) */
  48
  49 /*
  50  * In legal streams, the IDCT output should be between -384 and +384.
  51  * In corrupted streams, it is possible to force the IDCT output to go
  52  * to +-3826 - this is the worst case for a column IDCT where the
  53  * column inputs are 16-bit values.
  54  */
  55 #define CLIP(i) \
  56     ({ typeof (i) _i = (i); \
  57        if ((_i & 0xff) != _i) \
  58            _i = ~(_i >> (8*sizeof(_i) - 1)); \
  59        _i; })
  60
  61 #if 0
  62 #define BUTTERFLY(t0,t1,W0,W1,d0,d1) \
  63     do {                             \
  64         t0 = W0 * d0 + W1 * d1;      \
  65         t1 = W0 * d1 - W1 * d0;      \
  66     } while (0)
  67 #else
  68 #define BUTTERFLY(t0,t1,W0,W1,d0,d1) \
  69     do {                             \
  70         int tmp = W0 * (d0 + d1);    \
  71         t0 = tmp + (W1 - W0) * d1;   \
  72         t1 = tmp - (W1 + W0) * d0;   \
  73     } while (0)
  74 #endif
  75
  76 static inline void idct_row (int16_t * const block)
  77 {
  78     int d0, d1, d2, d3;
  79     int a0, a1, a2, a3, b0, b1, b2, b3;
  80     int t0, t1, t2, t3;
  81
  82     /* shortcut */
  83     if (likely (!(block[1] | ((int32_t *)block)[1] | ((int32_t *)block)[2] |
  84                  ((int32_t *)block)[3])))
  85     {
  86         uint32_t tmp = (uint16_t) (block[0] >> 1);
  87         tmp |= tmp << 16;
  88         ((int32_t *)block)[0] = tmp;
  89         ((int32_t *)block)[1] = tmp;
  90         ((int32_t *)block)[2] = tmp;
  91         ((int32_t *)block)[3] = tmp;
  92         return;
  93     }
  94
  95     d0 = (block[0] << 11) + 2048;
  96     d1 = block[1];
  97     d2 = block[2] << 11;
  98     d3 = block[3];
  99     t0 = d0 + d2;
 100     t1 = d0 - d2;
 101     BUTTERFLY (t2, t3, W6, W2, d3, d1);
 102     a0 = t0 + t2;
 103     a1 = t1 + t3;
 104     a2 = t1 - t3;
 105     a3 = t0 - t2;
 106
 107     d0 = block[4];
 108     d1 = block[5];
 109     d2 = block[6];
 110     d3 = block[7];
 111     BUTTERFLY (t0, t1, W7, W1, d3, d0);
 112     BUTTERFLY (t2, t3, W3, W5, d1, d2);
 113     b0 = t0 + t2;
 114     b3 = t1 + t3;
 115     t0 -= t2;
 116     t1 -= t3;
 117     b1 = ((t0 + t1) >> 8) * 181;
 118     b2 = ((t0 - t1) >> 8) * 181;
 119
 120     block[0] = (a0 + b0) >> 12;
 121     block[1] = (a1 + b1) >> 12;
 122     block[2] = (a2 + b2) >> 12;
 123     block[3] = (a3 + b3) >> 12;
 124     block[4] = (a3 - b3) >> 12;
 125     block[5] = (a2 - b2) >> 12;
 126     block[6] = (a1 - b1) >> 12;
 127     block[7] = (a0 - b0) >> 12;
 128 }
 129
 130 static inline void idct_col (int16_t * const block)
 131 {
 132     int d0, d1, d2, d3;
 133     int a0, a1, a2, a3, b0, b1, b2, b3;
 134     int t0, t1, t2, t3;
 135
 136     d0 = (block[8*0] << 11) + 65536;
 137     d1 = block[8*1];
 138     d2 = block[8*2] << 11;
 139     d3 = block[8*3];
 140     t0 = d0 + d2;
 141     t1 = d0 - d2;
 142     BUTTERFLY (t2, t3, W6, W2, d3, d1);
 143     a0 = t0 + t2;
 144     a1 = t1 + t3;
 145     a2 = t1 - t3;
 146     a3 = t0 - t2;
 147
 148     d0 = block[8*4];
 149     d1 = block[8*5];
 150     d2 = block[8*6];
 151     d3 = block[8*7];
 152     BUTTERFLY (t0, t1, W7, W1, d3, d0);
 153     BUTTERFLY (t2, t3, W3, W5, d1, d2);
 154     b0 = t0 + t2;
 155     b3 = t1 + t3;
 156     t0 -= t2;
 157     t1 -= t3;
 158     b1 = ((t0 + t1) >> 8) * 181;
 159     b2 = ((t0 - t1) >> 8) * 181;
 160
 161     block[8*0] = (a0 + b0) >> 17;
 162     block[8*1] = (a1 + b1) >> 17;
 163     block[8*2] = (a2 + b2) >> 17;
 164     block[8*3] = (a3 + b3) >> 17;
 165     block[8*4] = (a3 - b3) >> 17;
 166     block[8*5] = (a2 - b2) >> 17;
 167     block[8*6] = (a1 - b1) >> 17;
 168     block[8*7] = (a0 - b0) >> 17;
 169 }
 170
 171 void mpeg2_idct_copy (int16_t * block, uint8_t * dest,
 172                       const int stride)
 173 {
 174     int i;
 175
 176     for (i = 0; i < 8; i++)
 177         idct_row (block + 8 * i);
 178
 179     for (i = 0; i < 8; i++)
 180         idct_col (block + i);
 181
 182     do
 183     {
 184         dest[0] = CLIP (block[0]);
 185         dest[1] = CLIP (block[1]);
 186         dest[2] = CLIP (block[2]);
 187         dest[3] = CLIP (block[3]);
 188         dest[4] = CLIP (block[4]);
 189         dest[5] = CLIP (block[5]);
 190         dest[6] = CLIP (block[6]);
 191         dest[7] = CLIP (block[7]);
 192
 193         ((int32_t *)block)[0] = 0;
 194         ((int32_t *)block)[1] = 0;
 195         ((int32_t *)block)[2] = 0;
 196         ((int32_t *)block)[3] = 0;
 197
 198         dest += stride;
 199         block += 8;
 200     }
 201     while (--i);
 202 }
 203
 204 void mpeg2_idct_add (const int last, int16_t * block,
 205                      uint8_t * dest, const int stride)
 206 {
 207     int i;
 208
 209     if (last != 129 || (block[0] & (7 << 4)) == (4 << 4))
 210     {
 211         for (i = 0; i < 8; i++)
 212             idct_row (block + 8 * i);
 213
 214         for (i = 0; i < 8; i++)
 215             idct_col (block + i);
 216
 217         do
 218         {
 219             dest[0] = CLIP (block[0] + dest[0]);
 220             dest[1] = CLIP (block[1] + dest[1]);
 221             dest[2] = CLIP (block[2] + dest[2]);
 222             dest[3] = CLIP (block[3] + dest[3]);
 223             dest[4] = CLIP (block[4] + dest[4]);
 224             dest[5] = CLIP (block[5] + dest[5]);
 225             dest[6] = CLIP (block[6] + dest[6]);
 226             dest[7] = CLIP (block[7] + dest[7]);
 227
 228             ((int32_t *)block)[0] = 0;
 229             ((int32_t *)block)[1] = 0;
 230             ((int32_t *)block)[2] = 0;
 231             ((int32_t *)block)[3] = 0;
 232
 233             dest += stride;
 234             block += 8;
 235         }
 236         while (--i);
 237     }
 238     else
 239     {
 240         int DC = (block[0] + 64) >> 7;
 241         block[0] = block[63] = 0;
 242         i = 8;
 243
 244         do
 245         {
 246             dest[0] = CLIP (DC + dest[0]);
 247             dest[1] = CLIP (DC + dest[1]);
 248             dest[2] = CLIP (DC + dest[2]);
 249             dest[3] = CLIP (DC + dest[3]);
 250             dest[4] = CLIP (DC + dest[4]);
 251             dest[5] = CLIP (DC + dest[5]);
 252             dest[6] = CLIP (DC + dest[6]);
 253             dest[7] = CLIP (DC + dest[7]);
 254             dest += stride;
 255         }
 256         while (--i);
 257     }
 258 }
 259
 260 #endif /* IDCT_ASM */
 261
 262 void mpeg2_idct_init (void)
 263 {
 264     int i, j;
 265
 266     for (i = 0; i < 64; i++)
 267     {
 268         j = default_mpeg2_scan_norm[i];
 269         mpeg2_scan_norm[i] = ((j & 0x36) >> 1) | ((j & 0x09) << 2);
 270
 271         j = default_mpeg2_scan_alt[i];
 272         mpeg2_scan_alt[i] = ((j & 0x36) >> 1) | ((j & 0x09) << 2);
 273     }
 274 }