theora-old/lib/dct.c

   1 /********************************************************************
   2  *                                                                  *
   3  * THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE.   *
   4  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
   5  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
   6  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
   7  *                                                                  *
   8  * THE Theora SOURCE CODE IS COPYRIGHT (C) 2002-2003                *
   9  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  10  *                                                                  *
  11  ********************************************************************
  12
  13   function:
  14   last mod: $Id$
  15
  16  ********************************************************************/
  17
  18 #include "codec_internal.h"
  19
  20 static ogg_int32_t xC1S7 = 64277;
  21 static ogg_int32_t xC2S6 = 60547;
  22 static ogg_int32_t xC3S5 = 54491;
  23 static ogg_int32_t xC4S4 = 46341;
  24 static ogg_int32_t xC5S3 = 36410;
  25 static ogg_int32_t xC6S2 = 25080;
  26 static ogg_int32_t xC7S1 = 12785;
  27
  28 #define SIGNBITDUPPED(X) ((signed )(((X) & 0x80000000)) >> 31)
  29 #define DOROUND(X) ( (SIGNBITDUPPED(X) & (0xffff)) + (X) )
  30
  31 static void fdct_short__c ( ogg_int16_t * InputData, ogg_int16_t * OutputData ){
  32   int loop;
  33
  34   ogg_int32_t  is07, is12, is34, is56;
  35   ogg_int32_t  is0734, is1256;
  36   ogg_int32_t  id07, id12, id34, id56;
  37
  38   ogg_int32_t  irot_input_x, irot_input_y;
  39   ogg_int32_t  icommon_product1;   /* Re-used product  (c4s4 * (s12 - s56)). */
  40   ogg_int32_t  icommon_product2;   /* Re-used product  (c4s4 * (d12 + d56)). */
  41
  42   ogg_int32_t  temp1, temp2;         /* intermediate variable for computation */
  43
  44   ogg_int32_t  InterData[64];
  45   ogg_int32_t *ip = InterData;
  46   ogg_int16_t * op = OutputData;
  47   for (loop = 0; loop < 8; loop++){
  48     /* Pre calculate some common sums and differences. */
  49     is07 = InputData[0] + InputData[7];
  50     is12 = InputData[1] + InputData[2];
  51     is34 = InputData[3] + InputData[4];
  52     is56 = InputData[5] + InputData[6];
  53
  54     id07 = InputData[0] - InputData[7];
  55     id12 = InputData[1] - InputData[2];
  56     id34 = InputData[3] - InputData[4];
  57     id56 = InputData[5] - InputData[6];
  58
  59     is0734 = is07 + is34;
  60     is1256 = is12 + is56;
  61
  62     /* Pre-Calculate some common product terms. */
  63     icommon_product1 = xC4S4*(is12 - is56);
  64     icommon_product1 = DOROUND(icommon_product1);
  65     icommon_product1>>=16;
  66
  67     icommon_product2 = xC4S4*(id12 + id56);
  68     icommon_product2 = DOROUND(icommon_product2);
  69     icommon_product2>>=16;
  70
  71
  72     ip[0] = (xC4S4*(is0734 + is1256));
  73     ip[0] = DOROUND(ip[0]);
  74     ip[0] >>= 16;
  75
  76     ip[4] = (xC4S4*(is0734 - is1256));
  77     ip[4] = DOROUND(ip[4]);
  78     ip[4] >>= 16;
  79
  80     /* Define inputs to rotation for outputs 2 and 6 */
  81     irot_input_x = id12 - id56;
  82     irot_input_y = is07 - is34;
  83
  84     /* Apply rotation for outputs 2 and 6.  */
  85     temp1=xC6S2*irot_input_x;
  86     temp1=DOROUND(temp1);
  87     temp1>>=16;
  88     temp2=xC2S6*irot_input_y;
  89     temp2=DOROUND(temp2);
  90     temp2>>=16;
  91     ip[2] = temp1 + temp2;
  92
  93     temp1=xC6S2*irot_input_y;
  94     temp1=DOROUND(temp1);
  95     temp1>>=16;
  96     temp2=xC2S6*irot_input_x ;
  97     temp2=DOROUND(temp2);
  98     temp2>>=16;
  99     ip[6] = temp1 -temp2 ;
 100
 101     /* Define inputs to rotation for outputs 1 and 7  */
 102     irot_input_x = icommon_product1 + id07;
 103     irot_input_y = -( id34 + icommon_product2 );
 104
 105     /* Apply rotation for outputs 1 and 7.  */
 106
 107     temp1=xC1S7*irot_input_x;
 108     temp1=DOROUND(temp1);
 109     temp1>>=16;
 110     temp2=xC7S1*irot_input_y;
 111     temp2=DOROUND(temp2);
 112     temp2>>=16;
 113     ip[1] = temp1 - temp2;
 114
 115     temp1=xC7S1*irot_input_x;
 116     temp1=DOROUND(temp1);
 117     temp1>>=16;
 118     temp2=xC1S7*irot_input_y ;
 119     temp2=DOROUND(temp2);
 120     temp2>>=16;
 121     ip[7] = temp1 + temp2 ;
 122
 123     /* Define inputs to rotation for outputs 3 and 5 */
 124     irot_input_x = id07 - icommon_product1;
 125     irot_input_y = id34 - icommon_product2;
 126
 127     /* Apply rotation for outputs 3 and 5. */
 128     temp1=xC3S5*irot_input_x;
 129     temp1=DOROUND(temp1);
 130     temp1>>=16;
 131     temp2=xC5S3*irot_input_y ;
 132     temp2=DOROUND(temp2);
 133     temp2>>=16;
 134     ip[3] = temp1 - temp2 ;
 135
 136     temp1=xC5S3*irot_input_x;
 137     temp1=DOROUND(temp1);
 138     temp1>>=16;
 139     temp2=xC3S5*irot_input_y;
 140     temp2=DOROUND(temp2);
 141     temp2>>=16;
 142     ip[5] = temp1 + temp2;
 143
 144     /* Increment data pointer for next row. */
 145     InputData += 8 ;
 146     ip += 8; /* advance pointer to next row */
 147
 148   }
 149
 150
 151   /* Performed DCT on rows, now transform the columns */
 152   ip = InterData;
 153   for (loop = 0; loop < 8; loop++){
 154     /* Pre calculate some common sums and differences.  */
 155     is07 = ip[0 * 8] + ip[7 * 8];
 156     is12 = ip[1 * 8] + ip[2 * 8];
 157     is34 = ip[3 * 8] + ip[4 * 8];
 158     is56 = ip[5 * 8] + ip[6 * 8];
 159
 160     id07 = ip[0 * 8] - ip[7 * 8];
 161     id12 = ip[1 * 8] - ip[2 * 8];
 162     id34 = ip[3 * 8] - ip[4 * 8];
 163     id56 = ip[5 * 8] - ip[6 * 8];
 164
 165     is0734 = is07 + is34;
 166     is1256 = is12 + is56;
 167
 168     /* Pre-Calculate some common product terms. */
 169     icommon_product1 = xC4S4*(is12 - is56) ;
 170     icommon_product2 = xC4S4*(id12 + id56) ;
 171     icommon_product1 = DOROUND(icommon_product1);
 172     icommon_product2 = DOROUND(icommon_product2);
 173     icommon_product1>>=16;
 174     icommon_product2>>=16;
 175
 176
 177     temp1 = xC4S4*(is0734 + is1256) ;
 178     temp2 = xC4S4*(is0734 - is1256) ;
 179     temp1 = DOROUND(temp1);
 180     temp2 = DOROUND(temp2);
 181     temp1>>=16;
 182     temp2>>=16;
 183     op[0*8] = (ogg_int16_t) temp1;
 184     op[4*8] = (ogg_int16_t) temp2;
 185
 186     /* Define inputs to rotation for outputs 2 and 6 */
 187     irot_input_x = id12 - id56;
 188     irot_input_y = is07 - is34;
 189
 190     /* Apply rotation for outputs 2 and 6.  */
 191     temp1=xC6S2*irot_input_x;
 192     temp1=DOROUND(temp1);
 193     temp1>>=16;
 194     temp2=xC2S6*irot_input_y;
 195     temp2=DOROUND(temp2);
 196     temp2>>=16;
 197     op[2*8] = (ogg_int16_t) (temp1 + temp2);
 198
 199     temp1=xC6S2*irot_input_y;
 200     temp1=DOROUND(temp1);
 201     temp1>>=16;
 202     temp2=xC2S6*irot_input_x ;
 203     temp2=DOROUND(temp2);
 204     temp2>>=16;
 205     op[6*8] = (ogg_int16_t) (temp1 -temp2) ;
 206
 207     /* Define inputs to rotation for outputs 1 and 7 */
 208     irot_input_x = icommon_product1 + id07;
 209     irot_input_y = -( id34 + icommon_product2 );
 210
 211     /* Apply rotation for outputs 1 and 7. */
 212     temp1=xC1S7*irot_input_x;
 213     temp1=DOROUND(temp1);
 214     temp1>>=16;
 215     temp2=xC7S1*irot_input_y;
 216     temp2=DOROUND(temp2);
 217     temp2>>=16;
 218     op[1*8] = (ogg_int16_t) (temp1 - temp2);
 219
 220     temp1=xC7S1*irot_input_x;
 221     temp1=DOROUND(temp1);
 222     temp1>>=16;
 223     temp2=xC1S7*irot_input_y ;
 224     temp2=DOROUND(temp2);
 225     temp2>>=16;
 226     op[7*8] = (ogg_int16_t) (temp1 + temp2);
 227
 228     /* Define inputs to rotation for outputs 3 and 5 */
 229     irot_input_x = id07 - icommon_product1;
 230     irot_input_y = id34 - icommon_product2;
 231
 232     /* Apply rotation for outputs 3 and 5. */
 233     temp1=xC3S5*irot_input_x;
 234     temp1=DOROUND(temp1);
 235     temp1>>=16;
 236     temp2=xC5S3*irot_input_y ;
 237     temp2=DOROUND(temp2);
 238     temp2>>=16;
 239     op[3*8] = (ogg_int16_t) (temp1 - temp2) ;
 240
 241     temp1=xC5S3*irot_input_x;
 242     temp1=DOROUND(temp1);
 243     temp1>>=16;
 244     temp2=xC3S5*irot_input_y;
 245     temp2=DOROUND(temp2);
 246     temp2>>=16;
 247     op[5*8] = (ogg_int16_t) (temp1 + temp2);
 248
 249     /* Increment data pointer for next column.  */
 250     ip ++;
 251     op ++;
 252   }
 253 }
 254
 255 void dsp_dct_init (DspFunctions *funcs, ogg_uint32_t cpu_flags)
 256 {
 257   funcs->fdct_short = fdct_short__c;
 258   dsp_dct_decode_init(funcs, cpu_flags);
 259   dsp_idct_init(funcs, cpu_flags);
 260 #if defined(USE_ASM)
 261   if (cpu_flags & CPU_X86_MMX) {
 262     dsp_mmx_fdct_init(funcs);
 263   }
 264 #endif
 265 }
 266