tor-browser

The Tor Browser
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faandct.c (7058B)


      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
     23 * @brief
     24 *     Floating point AAN DCT
     25 * @author Michael Niedermayer <michaelni@gmx.at>
     26 */
     27 
     28 #include "faandct.h"
     29 #include "libavutil/emms.h"
     30 #include "libavutil/internal.h"
     31 #include "libavutil/libm.h"
     32 
     33 typedef float FLOAT;
     34 
     35 /* numbers generated by arbitrary precision arithmetic followed by truncation
     36 to 36 fractional digits (enough for a 128-bit IEEE quad, see /usr/include/math.h
     37 for this approach). Unfortunately, long double is not always available correctly,
     38 e.g ppc has issues.
     39 TODO: add L suffixes when ppc and toolchains sort out their stuff.
     40 */
     41 #define B0 1.000000000000000000000000000000000000
     42 #define B1 0.720959822006947913789091890943021267 // (cos(pi*1/16)sqrt(2))^-1
     43 #define B2 0.765366864730179543456919968060797734 // (cos(pi*2/16)sqrt(2))^-1
     44 #define B3 0.850430094767256448766702844371412325 // (cos(pi*3/16)sqrt(2))^-1
     45 #define B4 1.000000000000000000000000000000000000 // (cos(pi*4/16)sqrt(2))^-1
     46 #define B5 1.272758580572833938461007018281767032 // (cos(pi*5/16)sqrt(2))^-1
     47 #define B6 1.847759065022573512256366378793576574 // (cos(pi*6/16)sqrt(2))^-1
     48 #define B7 3.624509785411551372409941227504289587 // (cos(pi*7/16)sqrt(2))^-1
     49 
     50 #define A1 M_SQRT1_2              // cos(pi*4/16)
     51 #define A2 0.54119610014619698435 // cos(pi*6/16)sqrt(2)
     52 #define A5 0.38268343236508977170 // cos(pi*6/16)
     53 #define A4 1.30656296487637652774 // cos(pi*2/16)sqrt(2)
     54 
     55 static const FLOAT postscale[64]={
     56 B0*B0, B0*B1, B0*B2, B0*B3, B0*B4, B0*B5, B0*B6, B0*B7,
     57 B1*B0, B1*B1, B1*B2, B1*B3, B1*B4, B1*B5, B1*B6, B1*B7,
     58 B2*B0, B2*B1, B2*B2, B2*B3, B2*B4, B2*B5, B2*B6, B2*B7,
     59 B3*B0, B3*B1, B3*B2, B3*B3, B3*B4, B3*B5, B3*B6, B3*B7,
     60 B4*B0, B4*B1, B4*B2, B4*B3, B4*B4, B4*B5, B4*B6, B4*B7,
     61 B5*B0, B5*B1, B5*B2, B5*B3, B5*B4, B5*B5, B5*B6, B5*B7,
     62 B6*B0, B6*B1, B6*B2, B6*B3, B6*B4, B6*B5, B6*B6, B6*B7,
     63 B7*B0, B7*B1, B7*B2, B7*B3, B7*B4, B7*B5, B7*B6, B7*B7,
     64 };
     65 
     66 static av_always_inline void row_fdct(FLOAT temp[64], int16_t *data)
     67 {
     68    FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
     69    FLOAT tmp10, tmp11, tmp12, tmp13;
     70    FLOAT z2, z4, z11, z13;
     71    int i;
     72 
     73    for (i=0; i<8*8; i+=8) {
     74        tmp0= data[0 + i] + data[7 + i];
     75        tmp7= data[0 + i] - data[7 + i];
     76        tmp1= data[1 + i] + data[6 + i];
     77        tmp6= data[1 + i] - data[6 + i];
     78        tmp2= data[2 + i] + data[5 + i];
     79        tmp5= data[2 + i] - data[5 + i];
     80        tmp3= data[3 + i] + data[4 + i];
     81        tmp4= data[3 + i] - data[4 + i];
     82 
     83        tmp10= tmp0 + tmp3;
     84        tmp13= tmp0 - tmp3;
     85        tmp11= tmp1 + tmp2;
     86        tmp12= tmp1 - tmp2;
     87 
     88        temp[0 + i]= tmp10 + tmp11;
     89        temp[4 + i]= tmp10 - tmp11;
     90 
     91        tmp12 += tmp13;
     92        tmp12 *= A1;
     93        temp[2 + i]= tmp13 + tmp12;
     94        temp[6 + i]= tmp13 - tmp12;
     95 
     96        tmp4 += tmp5;
     97        tmp5 += tmp6;
     98        tmp6 += tmp7;
     99 
    100        z2= tmp4*(A2+A5) - tmp6*A5;
    101        z4= tmp6*(A4-A5) + tmp4*A5;
    102 
    103        tmp5*=A1;
    104 
    105        z11= tmp7 + tmp5;
    106        z13= tmp7 - tmp5;
    107 
    108        temp[5 + i]= z13 + z2;
    109        temp[3 + i]= z13 - z2;
    110        temp[1 + i]= z11 + z4;
    111        temp[7 + i]= z11 - z4;
    112    }
    113 }
    114 
    115 void ff_faandct(int16_t *data)
    116 {
    117    FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
    118    FLOAT tmp10, tmp11, tmp12, tmp13;
    119    FLOAT z2, z4, z11, z13;
    120    FLOAT temp[64];
    121    int i;
    122 
    123    emms_c();
    124 
    125    row_fdct(temp, data);
    126 
    127    for (i=0; i<8; i++) {
    128        tmp0= temp[8*0 + i] + temp[8*7 + i];
    129        tmp7= temp[8*0 + i] - temp[8*7 + i];
    130        tmp1= temp[8*1 + i] + temp[8*6 + i];
    131        tmp6= temp[8*1 + i] - temp[8*6 + i];
    132        tmp2= temp[8*2 + i] + temp[8*5 + i];
    133        tmp5= temp[8*2 + i] - temp[8*5 + i];
    134        tmp3= temp[8*3 + i] + temp[8*4 + i];
    135        tmp4= temp[8*3 + i] - temp[8*4 + i];
    136 
    137        tmp10= tmp0 + tmp3;
    138        tmp13= tmp0 - tmp3;
    139        tmp11= tmp1 + tmp2;
    140        tmp12= tmp1 - tmp2;
    141 
    142        data[8*0 + i]= lrintf(postscale[8*0 + i] * (tmp10 + tmp11));
    143        data[8*4 + i]= lrintf(postscale[8*4 + i] * (tmp10 - tmp11));
    144 
    145        tmp12 += tmp13;
    146        tmp12 *= A1;
    147        data[8*2 + i]= lrintf(postscale[8*2 + i] * (tmp13 + tmp12));
    148        data[8*6 + i]= lrintf(postscale[8*6 + i] * (tmp13 - tmp12));
    149 
    150        tmp4 += tmp5;
    151        tmp5 += tmp6;
    152        tmp6 += tmp7;
    153 
    154        z2= tmp4*(A2+A5) - tmp6*A5;
    155        z4= tmp6*(A4-A5) + tmp4*A5;
    156 
    157        tmp5*=A1;
    158 
    159        z11= tmp7 + tmp5;
    160        z13= tmp7 - tmp5;
    161 
    162        data[8*5 + i]= lrintf(postscale[8*5 + i] * (z13 + z2));
    163        data[8*3 + i]= lrintf(postscale[8*3 + i] * (z13 - z2));
    164        data[8*1 + i]= lrintf(postscale[8*1 + i] * (z11 + z4));
    165        data[8*7 + i]= lrintf(postscale[8*7 + i] * (z11 - z4));
    166    }
    167 }
    168 
    169 void ff_faandct248(int16_t *data)
    170 {
    171    FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
    172    FLOAT tmp10, tmp11, tmp12, tmp13;
    173    FLOAT temp[64];
    174    int i;
    175 
    176    emms_c();
    177 
    178    row_fdct(temp, data);
    179 
    180    for (i=0; i<8; i++) {
    181        tmp0 = temp[8*0 + i] + temp[8*1 + i];
    182        tmp1 = temp[8*2 + i] + temp[8*3 + i];
    183        tmp2 = temp[8*4 + i] + temp[8*5 + i];
    184        tmp3 = temp[8*6 + i] + temp[8*7 + i];
    185        tmp4 = temp[8*0 + i] - temp[8*1 + i];
    186        tmp5 = temp[8*2 + i] - temp[8*3 + i];
    187        tmp6 = temp[8*4 + i] - temp[8*5 + i];
    188        tmp7 = temp[8*6 + i] - temp[8*7 + i];
    189 
    190        tmp10 = tmp0 + tmp3;
    191        tmp11 = tmp1 + tmp2;
    192        tmp12 = tmp1 - tmp2;
    193        tmp13 = tmp0 - tmp3;
    194 
    195        data[8*0 + i] = lrintf(postscale[8*0 + i] * (tmp10 + tmp11));
    196        data[8*4 + i] = lrintf(postscale[8*4 + i] * (tmp10 - tmp11));
    197 
    198        tmp12 += tmp13;
    199        tmp12 *= A1;
    200        data[8*2 + i] = lrintf(postscale[8*2 + i] * (tmp13 + tmp12));
    201        data[8*6 + i] = lrintf(postscale[8*6 + i] * (tmp13 - tmp12));
    202 
    203        tmp10 = tmp4 + tmp7;
    204        tmp11 = tmp5 + tmp6;
    205        tmp12 = tmp5 - tmp6;
    206        tmp13 = tmp4 - tmp7;
    207 
    208        data[8*1 + i] = lrintf(postscale[8*0 + i] * (tmp10 + tmp11));
    209        data[8*5 + i] = lrintf(postscale[8*4 + i] * (tmp10 - tmp11));
    210 
    211        tmp12 += tmp13;
    212        tmp12 *= A1;
    213        data[8*3 + i] = lrintf(postscale[8*2 + i] * (tmp13 + tmp12));
    214        data[8*7 + i] = lrintf(postscale[8*6 + i] * (tmp13 - tmp12));
    215    }
    216 }