libmpeg2/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  * Modified for use with MPlayer, see libmpeg-0.4.1.diff for the exact changes.
  24  * detailed changelog at http://svn.mplayerhq.hu/mplayer/trunk/
  25  * $Id$
  26  */
  27
  28 #include "config.h"
  29
  30 #include <stdlib.h>
  31 #include <inttypes.h>
  32
  33 #include "mpeg2.h"
  34 #include "attributes.h"
  35 #include "mpeg2_internal.h"
  36
  37 #define W1 2841 /* 2048 * sqrt (2) * cos (1 * pi / 16) */
  38 #define W2 2676 /* 2048 * sqrt (2) * cos (2 * pi / 16) */
  39 #define W3 2408 /* 2048 * sqrt (2) * cos (3 * pi / 16) */
  40 #define W5 1609 /* 2048 * sqrt (2) * cos (5 * pi / 16) */
  41 #define W6 1108 /* 2048 * sqrt (2) * cos (6 * pi / 16) */
  42 #define W7 565  /* 2048 * sqrt (2) * cos (7 * pi / 16) */
  43
  44 /* idct main entry point  */
  45 void (* mpeg2_idct_copy) (int16_t * block, uint8_t * dest, int stride);
  46 void (* mpeg2_idct_add) (int last, int16_t * block,
  47                          uint8_t * dest, int stride);
  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 uint8_t mpeg2_clip[3840 * 2 + 256];
  56 #define CLIP(i) ((mpeg2_clip + 3840)[i])
  57
  58 #if 0
  59 #define BUTTERFLY(t0,t1,W0,W1,d0,d1)    \
  60 do {                                    \
  61     t0 = W0 * d0 + W1 * d1;             \
  62     t1 = W0 * d1 - W1 * d0;             \
  63 } while (0)
  64 #else
  65 #define BUTTERFLY(t0,t1,W0,W1,d0,d1)    \
  66 do {                                    \
  67     int tmp = W0 * (d0 + d1);           \
  68     t0 = tmp + (W1 - W0) * d1;          \
  69     t1 = tmp - (W1 + W0) * d0;          \
  70 } while (0)
  71 #endif
  72
  73 static inline void idct_row (int16_t * const block)
  74 {
  75     int d0, d1, d2, d3;
  76     int a0, a1, a2, a3, b0, b1, b2, b3;
  77     int t0, t1, t2, t3;
  78
  79     /* shortcut */
  80     if (likely (!(block[1] | ((int32_t *)block)[1] | ((int32_t *)block)[2] |
  81                   ((int32_t *)block)[3]))) {
  82         uint32_t tmp = (uint16_t) (block[0] >> 1);
  83         tmp |= tmp << 16;
  84         ((int32_t *)block)[0] = tmp;
  85         ((int32_t *)block)[1] = tmp;
  86         ((int32_t *)block)[2] = tmp;
  87         ((int32_t *)block)[3] = tmp;
  88         return;
  89     }
  90
  91     d0 = (block[0] << 11) + 2048;
  92     d1 = block[1];
  93     d2 = block[2] << 11;
  94     d3 = block[3];
  95     t0 = d0 + d2;
  96     t1 = d0 - d2;
  97     BUTTERFLY (t2, t3, W6, W2, d3, d1);
  98     a0 = t0 + t2;
  99     a1 = t1 + t3;
 100     a2 = t1 - t3;
 101     a3 = t0 - t2;
 102
 103     d0 = block[4];
 104     d1 = block[5];
 105     d2 = block[6];
 106     d3 = block[7];
 107     BUTTERFLY (t0, t1, W7, W1, d3, d0);
 108     BUTTERFLY (t2, t3, W3, W5, d1, d2);
 109     b0 = t0 + t2;
 110     b3 = t1 + t3;
 111     t0 -= t2;
 112     t1 -= t3;
 113     b1 = ((t0 + t1) >> 8) * 181;
 114     b2 = ((t0 - t1) >> 8) * 181;
 115
 116     block[0] = (a0 + b0) >> 12;
 117     block[1] = (a1 + b1) >> 12;
 118     block[2] = (a2 + b2) >> 12;
 119     block[3] = (a3 + b3) >> 12;
 120     block[4] = (a3 - b3) >> 12;
 121     block[5] = (a2 - b2) >> 12;
 122     block[6] = (a1 - b1) >> 12;
 123     block[7] = (a0 - b0) >> 12;
 124 }
 125
 126 static inline void idct_col (int16_t * const block)
 127 {
 128     int d0, d1, d2, d3;
 129     int a0, a1, a2, a3, b0, b1, b2, b3;
 130     int t0, t1, t2, t3;
 131
 132     d0 = (block[8*0] << 11) + 65536;
 133     d1 = block[8*1];
 134     d2 = block[8*2] << 11;
 135     d3 = block[8*3];
 136     t0 = d0 + d2;
 137     t1 = d0 - d2;
 138     BUTTERFLY (t2, t3, W6, W2, d3, d1);
 139     a0 = t0 + t2;
 140     a1 = t1 + t3;
 141     a2 = t1 - t3;
 142     a3 = t0 - t2;
 143
 144     d0 = block[8*4];
 145     d1 = block[8*5];
 146     d2 = block[8*6];
 147     d3 = block[8*7];
 148     BUTTERFLY (t0, t1, W7, W1, d3, d0);
 149     BUTTERFLY (t2, t3, W3, W5, d1, d2);
 150     b0 = t0 + t2;
 151     b3 = t1 + t3;
 152     t0 -= t2;
 153     t1 -= t3;
 154     b1 = ((t0 + t1) >> 8) * 181;
 155     b2 = ((t0 - t1) >> 8) * 181;
 156
 157     block[8*0] = (a0 + b0) >> 17;
 158     block[8*1] = (a1 + b1) >> 17;
 159     block[8*2] = (a2 + b2) >> 17;
 160     block[8*3] = (a3 + b3) >> 17;
 161     block[8*4] = (a3 - b3) >> 17;
 162     block[8*5] = (a2 - b2) >> 17;
 163     block[8*6] = (a1 - b1) >> 17;
 164     block[8*7] = (a0 - b0) >> 17;
 165 }
 166
 167 static void mpeg2_idct_copy_c (int16_t * block, uint8_t * dest,
 168                                const int stride)
 169 {
 170     int i;
 171
 172     for (i = 0; i < 8; i++)
 173         idct_row (block + 8 * i);
 174     for (i = 0; i < 8; i++)
 175         idct_col (block + i);
 176     do {
 177         dest[0] = CLIP (block[0]);
 178         dest[1] = CLIP (block[1]);
 179         dest[2] = CLIP (block[2]);
 180         dest[3] = CLIP (block[3]);
 181         dest[4] = CLIP (block[4]);
 182         dest[5] = CLIP (block[5]);
 183         dest[6] = CLIP (block[6]);
 184         dest[7] = CLIP (block[7]);
 185
 186         ((int32_t *)block)[0] = 0;      ((int32_t *)block)[1] = 0;
 187         ((int32_t *)block)[2] = 0;      ((int32_t *)block)[3] = 0;
 188
 189         dest += stride;
 190         block += 8;
 191     } while (--i);
 192 }
 193
 194 static void mpeg2_idct_add_c (const int last, int16_t * block,
 195                               uint8_t * dest, const int stride)
 196 {
 197     int i;
 198
 199     if (last != 129 || (block[0] & (7 << 4)) == (4 << 4)) {
 200         for (i = 0; i < 8; i++)
 201             idct_row (block + 8 * i);
 202         for (i = 0; i < 8; i++)
 203             idct_col (block + i);
 204         do {
 205             dest[0] = CLIP (block[0] + dest[0]);
 206             dest[1] = CLIP (block[1] + dest[1]);
 207             dest[2] = CLIP (block[2] + dest[2]);
 208             dest[3] = CLIP (block[3] + dest[3]);
 209             dest[4] = CLIP (block[4] + dest[4]);
 210             dest[5] = CLIP (block[5] + dest[5]);
 211             dest[6] = CLIP (block[6] + dest[6]);
 212             dest[7] = CLIP (block[7] + dest[7]);
 213
 214             ((int32_t *)block)[0] = 0;  ((int32_t *)block)[1] = 0;
 215             ((int32_t *)block)[2] = 0;  ((int32_t *)block)[3] = 0;
 216
 217             dest += stride;
 218             block += 8;
 219         } while (--i);
 220     } else {
 221         int DC;
 222
 223         DC = (block[0] + 64) >> 7;
 224         block[0] = block[63] = 0;
 225         i = 8;
 226         do {
 227             dest[0] = CLIP (DC + dest[0]);
 228             dest[1] = CLIP (DC + dest[1]);
 229             dest[2] = CLIP (DC + dest[2]);
 230             dest[3] = CLIP (DC + dest[3]);
 231             dest[4] = CLIP (DC + dest[4]);
 232             dest[5] = CLIP (DC + dest[5]);
 233             dest[6] = CLIP (DC + dest[6]);
 234             dest[7] = CLIP (DC + dest[7]);
 235             dest += stride;
 236         } while (--i);
 237     }
 238 }
 239
 240 void mpeg2_idct_init (uint32_t accel)
 241 {
 242 #ifdef HAVE_MMX2
 243     if (accel & MPEG2_ACCEL_X86_MMXEXT) {
 244         mpeg2_idct_copy = mpeg2_idct_copy_mmxext;
 245         mpeg2_idct_add = mpeg2_idct_add_mmxext;
 246         mpeg2_idct_mmx_init ();
 247     } else
 248 #endif
 249 #ifdef HAVE_MMX
 250     if (accel & MPEG2_ACCEL_X86_MMX) {
 251         mpeg2_idct_copy = mpeg2_idct_copy_mmx;
 252         mpeg2_idct_add = mpeg2_idct_add_mmx;
 253         mpeg2_idct_mmx_init ();
 254     } else
 255 #endif
 256 #if defined(ARCH_PPC) && defined(HAVE_ALTIVEC)
 257     if (accel & MPEG2_ACCEL_PPC_ALTIVEC) {
 258         mpeg2_idct_copy = mpeg2_idct_copy_altivec;
 259         mpeg2_idct_add = mpeg2_idct_add_altivec;
 260         mpeg2_idct_altivec_init ();
 261     } else
 262 #endif
 263 #ifdef ARCH_ALPHA
 264 #ifdef CAN_COMPILE_ALPHA_MVI
 265     if (accel & MPEG2_ACCEL_ALPHA_MVI) {
 266         mpeg2_idct_copy = mpeg2_idct_copy_mvi;
 267         mpeg2_idct_add = mpeg2_idct_add_mvi;
 268         mpeg2_idct_alpha_init ();
 269     } else
 270 #endif
 271     if (accel & MPEG2_ACCEL_ALPHA) {
 272         int i;
 273
 274         mpeg2_idct_copy = mpeg2_idct_copy_alpha;
 275         mpeg2_idct_add = mpeg2_idct_add_alpha;
 276         mpeg2_idct_alpha_init ();
 277         for (i = -3840; i < 3840 + 256; i++)
 278             CLIP(i) = (i < 0) ? 0 : ((i > 255) ? 255 : i);
 279     } else
 280 #endif
 281     {
 282         extern uint8_t mpeg2_scan_norm[64];
 283         extern uint8_t mpeg2_scan_alt[64];
 284         int i, j;
 285
 286         mpeg2_idct_copy = mpeg2_idct_copy_c;
 287         mpeg2_idct_add = mpeg2_idct_add_c;
 288         for (i = -3840; i < 3840 + 256; i++)
 289             CLIP(i) = (i < 0) ? 0 : ((i > 255) ? 255 : i);
 290         for (i = 0; i < 64; i++) {
 291             j = mpeg2_scan_norm[i];
 292             mpeg2_scan_norm[i] = ((j & 0x36) >> 1) | ((j & 0x09) << 2);
 293             j = mpeg2_scan_alt[i];
 294             mpeg2_scan_alt[i] = ((j & 0x36) >> 1) | ((j & 0x09) << 2);
 295         }
 296     }
 297 }