libavcodec/faandct.c

   1 /*
   2  * Floating point AAN DCT
   3  * this implementation is based upon the IJG integer AAN DCT (see jfdctfst.c)
   4  *
   5  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
   6  * Copyright (c) 2003 Roman Shaposhnik
   7  *
   8  * Permission to use, copy, modify, and/or distribute this software for any
   9  * purpose with or without fee is hereby granted, provided that the above
  10  * copyright notice and this permission notice appear in all copies.
  11  *
  12  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  13  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  14  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  15  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  16  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  17  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  18  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  19  */
  20
  21 /**
  22  * @file libavcodec/faandct.c
  23  * @brief
  24  *     Floating point AAN DCT
  25  * @author Michael Niedermayer <michaelni@gmx.at>
  26  */
  27
  28 #include "dsputil.h"
  29 #include "faandct.h"
  30
  31 #define FLOAT float
  32 #ifdef FAAN_POSTSCALE
  33 #    define SCALE(x) postscale[x]
  34 #else
  35 #    define SCALE(x) 1
  36 #endif
  37
  38 //numbers generated by simple c code (not as accurate as they could be)
  39 /*
  40 for(i=0; i<8; i++){
  41     printf("#define B%d %1.20llf\n", i, (long double)1.0/(cosl(i*acosl(-1.0)/(long double)16.0)*sqrtl(2)));
  42 }
  43 */
  44 #define B0 1.00000000000000000000
  45 #define B1 0.72095982200694791383 // (cos(pi*1/16)sqrt(2))^-1
  46 #define B2 0.76536686473017954350 // (cos(pi*2/16)sqrt(2))^-1
  47 #define B3 0.85043009476725644878 // (cos(pi*3/16)sqrt(2))^-1
  48 #define B4 1.00000000000000000000 // (cos(pi*4/16)sqrt(2))^-1
  49 #define B5 1.27275858057283393842 // (cos(pi*5/16)sqrt(2))^-1
  50 #define B6 1.84775906502257351242 // (cos(pi*6/16)sqrt(2))^-1
  51 #define B7 3.62450978541155137218 // (cos(pi*7/16)sqrt(2))^-1
  52
  53
  54 #define A1 0.70710678118654752438 // cos(pi*4/16)
  55 #define A2 0.54119610014619698435 // cos(pi*6/16)sqrt(2)
  56 #define A5 0.38268343236508977170 // cos(pi*6/16)
  57 #define A4 1.30656296487637652774 // cos(pi*2/16)sqrt(2)
  58
  59 static const FLOAT postscale[64]={
  60 B0*B0, B0*B1, B0*B2, B0*B3, B0*B4, B0*B5, B0*B6, B0*B7,
  61 B1*B0, B1*B1, B1*B2, B1*B3, B1*B4, B1*B5, B1*B6, B1*B7,
  62 B2*B0, B2*B1, B2*B2, B2*B3, B2*B4, B2*B5, B2*B6, B2*B7,
  63 B3*B0, B3*B1, B3*B2, B3*B3, B3*B4, B3*B5, B3*B6, B3*B7,
  64 B4*B0, B4*B1, B4*B2, B4*B3, B4*B4, B4*B5, B4*B6, B4*B7,
  65 B5*B0, B5*B1, B5*B2, B5*B3, B5*B4, B5*B5, B5*B6, B5*B7,
  66 B6*B0, B6*B1, B6*B2, B6*B3, B6*B4, B6*B5, B6*B6, B6*B7,
  67 B7*B0, B7*B1, B7*B2, B7*B3, B7*B4, B7*B5, B7*B6, B7*B7,
  68 };
  69
  70 static av_always_inline void row_fdct(FLOAT temp[64], DCTELEM * data)
  71 {
  72     FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
  73     FLOAT tmp10, tmp11, tmp12, tmp13;
  74     FLOAT z2, z4, z11, z13;
  75     FLOAT av_unused z5;
  76     int i;
  77
  78     for (i=0; i<8*8; i+=8) {
  79         tmp0= data[0 + i] + data[7 + i];
  80         tmp7= data[0 + i] - data[7 + i];
  81         tmp1= data[1 + i] + data[6 + i];
  82         tmp6= data[1 + i] - data[6 + i];
  83         tmp2= data[2 + i] + data[5 + i];
  84         tmp5= data[2 + i] - data[5 + i];
  85         tmp3= data[3 + i] + data[4 + i];
  86         tmp4= data[3 + i] - data[4 + i];
  87
  88         tmp10= tmp0 + tmp3;
  89         tmp13= tmp0 - tmp3;
  90         tmp11= tmp1 + tmp2;
  91         tmp12= tmp1 - tmp2;
  92
  93         temp[0 + i]= tmp10 + tmp11;
  94         temp[4 + i]= tmp10 - tmp11;
  95
  96         tmp12 += tmp13;
  97         tmp12 *= A1;
  98         temp[2 + i]= tmp13 + tmp12;
  99         temp[6 + i]= tmp13 - tmp12;
 100
 101         tmp4 += tmp5;
 102         tmp5 += tmp6;
 103         tmp6 += tmp7;
 104
 105 #if 0
 106         z5= (tmp4 - tmp6) * A5;
 107         z2= tmp4*A2 + z5;
 108         z4= tmp6*A4 + z5;
 109 #else
 110         z2= tmp4*(A2+A5) - tmp6*A5;
 111         z4= tmp6*(A4-A5) + tmp4*A5;
 112 #endif
 113         tmp5*=A1;
 114
 115         z11= tmp7 + tmp5;
 116         z13= tmp7 - tmp5;
 117
 118         temp[5 + i]= z13 + z2;
 119         temp[3 + i]= z13 - z2;
 120         temp[1 + i]= z11 + z4;
 121         temp[7 + i]= z11 - z4;
 122     }
 123 }
 124
 125 void ff_faandct(DCTELEM * data)
 126 {
 127     FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
 128     FLOAT tmp10, tmp11, tmp12, tmp13;
 129     FLOAT z2, z4, z11, z13;
 130     FLOAT av_unused z5;
 131     FLOAT temp[64];
 132     int i;
 133
 134     emms_c();
 135
 136     row_fdct(temp, data);
 137
 138     for (i=0; i<8; i++) {
 139         tmp0= temp[8*0 + i] + temp[8*7 + i];
 140         tmp7= temp[8*0 + i] - temp[8*7 + i];
 141         tmp1= temp[8*1 + i] + temp[8*6 + i];
 142         tmp6= temp[8*1 + i] - temp[8*6 + i];
 143         tmp2= temp[8*2 + i] + temp[8*5 + i];
 144         tmp5= temp[8*2 + i] - temp[8*5 + i];
 145         tmp3= temp[8*3 + i] + temp[8*4 + i];
 146         tmp4= temp[8*3 + i] - temp[8*4 + i];
 147
 148         tmp10= tmp0 + tmp3;
 149         tmp13= tmp0 - tmp3;
 150         tmp11= tmp1 + tmp2;
 151         tmp12= tmp1 - tmp2;
 152
 153         data[8*0 + i]= lrintf(SCALE(8*0 + i) * (tmp10 + tmp11));
 154         data[8*4 + i]= lrintf(SCALE(8*4 + i) * (tmp10 - tmp11));
 155
 156         tmp12 += tmp13;
 157         tmp12 *= A1;
 158         data[8*2 + i]= lrintf(SCALE(8*2 + i) * (tmp13 + tmp12));
 159         data[8*6 + i]= lrintf(SCALE(8*6 + i) * (tmp13 - tmp12));
 160
 161         tmp4 += tmp5;
 162         tmp5 += tmp6;
 163         tmp6 += tmp7;
 164
 165 #if 0
 166         z5= (tmp4 - tmp6) * A5;
 167         z2= tmp4*A2 + z5;
 168         z4= tmp6*A4 + z5;
 169 #else
 170         z2= tmp4*(A2+A5) - tmp6*A5;
 171         z4= tmp6*(A4-A5) + tmp4*A5;
 172 #endif
 173         tmp5*=A1;
 174
 175         z11= tmp7 + tmp5;
 176         z13= tmp7 - tmp5;
 177
 178         data[8*5 + i]= lrintf(SCALE(8*5 + i) * (z13 + z2));
 179         data[8*3 + i]= lrintf(SCALE(8*3 + i) * (z13 - z2));
 180         data[8*1 + i]= lrintf(SCALE(8*1 + i) * (z11 + z4));
 181         data[8*7 + i]= lrintf(SCALE(8*7 + i) * (z11 - z4));
 182     }
 183 }
 184
 185 void ff_faandct248(DCTELEM * data)
 186 {
 187     FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
 188     FLOAT tmp10, tmp11, tmp12, tmp13;
 189     FLOAT temp[64];
 190     int i;
 191
 192     emms_c();
 193
 194     row_fdct(temp, data);
 195
 196     for (i=0; i<8; i++) {
 197         tmp0 = temp[8*0 + i] + temp[8*1 + i];
 198         tmp1 = temp[8*2 + i] + temp[8*3 + i];
 199         tmp2 = temp[8*4 + i] + temp[8*5 + i];
 200         tmp3 = temp[8*6 + i] + temp[8*7 + i];
 201         tmp4 = temp[8*0 + i] - temp[8*1 + i];
 202         tmp5 = temp[8*2 + i] - temp[8*3 + i];
 203         tmp6 = temp[8*4 + i] - temp[8*5 + i];
 204         tmp7 = temp[8*6 + i] - temp[8*7 + i];
 205
 206         tmp10 = tmp0 + tmp3;
 207         tmp11 = tmp1 + tmp2;
 208         tmp12 = tmp1 - tmp2;
 209         tmp13 = tmp0 - tmp3;
 210
 211         data[8*0 + i] = lrintf(SCALE(8*0 + i) * (tmp10 + tmp11));
 212         data[8*4 + i] = lrintf(SCALE(8*4 + i) * (tmp10 - tmp11));
 213
 214         tmp12 += tmp13;
 215         tmp12 *= A1;
 216         data[8*2 + i] = lrintf(SCALE(8*2 + i) * (tmp13 + tmp12));
 217         data[8*6 + i] = lrintf(SCALE(8*6 + i) * (tmp13 - tmp12));
 218
 219         tmp10 = tmp4 + tmp7;
 220         tmp11 = tmp5 + tmp6;
 221         tmp12 = tmp5 - tmp6;
 222         tmp13 = tmp4 - tmp7;
 223
 224         data[8*1 + i] = lrintf(SCALE(8*0 + i) * (tmp10 + tmp11));
 225         data[8*5 + i] = lrintf(SCALE(8*4 + i) * (tmp10 - tmp11));
 226
 227         tmp12 += tmp13;
 228         tmp12 *= A1;
 229         data[8*3 + i] = lrintf(SCALE(8*2 + i) * (tmp13 + tmp12));
 230         data[8*7 + i] = lrintf(SCALE(8*6 + i) * (tmp13 - tmp12));
 231     }
 232 }