FFmpeg: libavcodec/faandct.c Source File

00001 /*
00002  * Floating point AAN DCT
00003  * this implementation is based upon the IJG integer AAN DCT (see jfdctfst.c)
00004  *
00005  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
00006  * Copyright (c) 2003 Roman Shaposhnik
00007  *
00008  * Permission to use, copy, modify, and/or distribute this software for any
00009  * purpose with or without fee is hereby granted, provided that the above
00010  * copyright notice and this permission notice appear in all copies.
00011  *
00012  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
00013  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
00014  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
00015  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
00016  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
00017  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
00018  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
00019  */
00020 
00028 #include "dsputil.h"
00029 #include "faandct.h"
00030 
00031 #define FLOAT float
00032 #ifdef FAAN_POSTSCALE
00033 #    define SCALE(x) postscale[x]
00034 #else
00035 #    define SCALE(x) 1
00036 #endif
00037 
00038 //numbers generated by simple c code (not as accurate as they could be)
00039 /*
00040 for(i=0; i<8; i++){
00041     printf("#define B%d %1.20llf\n", i, (long double)1.0/(cosl(i*acosl(-1.0)/(long double)16.0)*sqrtl(2)));
00042 }
00043 */
00044 #define B0 1.00000000000000000000
00045 #define B1 0.72095982200694791383 // (cos(pi*1/16)sqrt(2))^-1
00046 #define B2 0.76536686473017954350 // (cos(pi*2/16)sqrt(2))^-1
00047 #define B3 0.85043009476725644878 // (cos(pi*3/16)sqrt(2))^-1
00048 #define B4 1.00000000000000000000 // (cos(pi*4/16)sqrt(2))^-1
00049 #define B5 1.27275858057283393842 // (cos(pi*5/16)sqrt(2))^-1
00050 #define B6 1.84775906502257351242 // (cos(pi*6/16)sqrt(2))^-1
00051 #define B7 3.62450978541155137218 // (cos(pi*7/16)sqrt(2))^-1
00052 
00053 
00054 #define A1 0.70710678118654752438 // cos(pi*4/16)
00055 #define A2 0.54119610014619698435 // cos(pi*6/16)sqrt(2)
00056 #define A5 0.38268343236508977170 // cos(pi*6/16)
00057 #define A4 1.30656296487637652774 // cos(pi*2/16)sqrt(2)
00058 
00059 static const FLOAT postscale[64]={
00060 B0*B0, B0*B1, B0*B2, B0*B3, B0*B4, B0*B5, B0*B6, B0*B7,
00061 B1*B0, B1*B1, B1*B2, B1*B3, B1*B4, B1*B5, B1*B6, B1*B7,
00062 B2*B0, B2*B1, B2*B2, B2*B3, B2*B4, B2*B5, B2*B6, B2*B7,
00063 B3*B0, B3*B1, B3*B2, B3*B3, B3*B4, B3*B5, B3*B6, B3*B7,
00064 B4*B0, B4*B1, B4*B2, B4*B3, B4*B4, B4*B5, B4*B6, B4*B7,
00065 B5*B0, B5*B1, B5*B2, B5*B3, B5*B4, B5*B5, B5*B6, B5*B7,
00066 B6*B0, B6*B1, B6*B2, B6*B3, B6*B4, B6*B5, B6*B6, B6*B7,
00067 B7*B0, B7*B1, B7*B2, B7*B3, B7*B4, B7*B5, B7*B6, B7*B7,
00068 };
00069 
00070 static av_always_inline void row_fdct(FLOAT temp[64], DCTELEM * data)
00071 {
00072     FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
00073     FLOAT tmp10, tmp11, tmp12, tmp13;
00074     FLOAT z2, z4, z11, z13;
00075     FLOAT av_unused z5;
00076     int i;
00077 
00078     for (i=0; i<8*8; i+=8) {
00079         tmp0= data[0 + i] + data[7 + i];
00080         tmp7= data[0 + i] - data[7 + i];
00081         tmp1= data[1 + i] + data[6 + i];
00082         tmp6= data[1 + i] - data[6 + i];
00083         tmp2= data[2 + i] + data[5 + i];
00084         tmp5= data[2 + i] - data[5 + i];
00085         tmp3= data[3 + i] + data[4 + i];
00086         tmp4= data[3 + i] - data[4 + i];
00087 
00088         tmp10= tmp0 + tmp3;
00089         tmp13= tmp0 - tmp3;
00090         tmp11= tmp1 + tmp2;
00091         tmp12= tmp1 - tmp2;
00092 
00093         temp[0 + i]= tmp10 + tmp11;
00094         temp[4 + i]= tmp10 - tmp11;
00095 
00096         tmp12 += tmp13;
00097         tmp12 *= A1;
00098         temp[2 + i]= tmp13 + tmp12;
00099         temp[6 + i]= tmp13 - tmp12;
00100 
00101         tmp4 += tmp5;
00102         tmp5 += tmp6;
00103         tmp6 += tmp7;
00104 
00105 #if 0
00106         z5= (tmp4 - tmp6) * A5;
00107         z2= tmp4*A2 + z5;
00108         z4= tmp6*A4 + z5;
00109 #else
00110         z2= tmp4*(A2+A5) - tmp6*A5;
00111         z4= tmp6*(A4-A5) + tmp4*A5;
00112 #endif
00113         tmp5*=A1;
00114 
00115         z11= tmp7 + tmp5;
00116         z13= tmp7 - tmp5;
00117 
00118         temp[5 + i]= z13 + z2;
00119         temp[3 + i]= z13 - z2;
00120         temp[1 + i]= z11 + z4;
00121         temp[7 + i]= z11 - z4;
00122     }
00123 }
00124 
00125 void ff_faandct(DCTELEM * data)
00126 {
00127     FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
00128     FLOAT tmp10, tmp11, tmp12, tmp13;
00129     FLOAT z2, z4, z11, z13;
00130     FLOAT av_unused z5;
00131     FLOAT temp[64];
00132     int i;
00133 
00134     emms_c();
00135 
00136     row_fdct(temp, data);
00137 
00138     for (i=0; i<8; i++) {
00139         tmp0= temp[8*0 + i] + temp[8*7 + i];
00140         tmp7= temp[8*0 + i] - temp[8*7 + i];
00141         tmp1= temp[8*1 + i] + temp[8*6 + i];
00142         tmp6= temp[8*1 + i] - temp[8*6 + i];
00143         tmp2= temp[8*2 + i] + temp[8*5 + i];
00144         tmp5= temp[8*2 + i] - temp[8*5 + i];
00145         tmp3= temp[8*3 + i] + temp[8*4 + i];
00146         tmp4= temp[8*3 + i] - temp[8*4 + i];
00147 
00148         tmp10= tmp0 + tmp3;
00149         tmp13= tmp0 - tmp3;
00150         tmp11= tmp1 + tmp2;
00151         tmp12= tmp1 - tmp2;
00152 
00153         data[8*0 + i]= lrintf(SCALE(8*0 + i) * (tmp10 + tmp11));
00154         data[8*4 + i]= lrintf(SCALE(8*4 + i) * (tmp10 - tmp11));
00155 
00156         tmp12 += tmp13;
00157         tmp12 *= A1;
00158         data[8*2 + i]= lrintf(SCALE(8*2 + i) * (tmp13 + tmp12));
00159         data[8*6 + i]= lrintf(SCALE(8*6 + i) * (tmp13 - tmp12));
00160 
00161         tmp4 += tmp5;
00162         tmp5 += tmp6;
00163         tmp6 += tmp7;
00164 
00165 #if 0
00166         z5= (tmp4 - tmp6) * A5;
00167         z2= tmp4*A2 + z5;
00168         z4= tmp6*A4 + z5;
00169 #else
00170         z2= tmp4*(A2+A5) - tmp6*A5;
00171         z4= tmp6*(A4-A5) + tmp4*A5;
00172 #endif
00173         tmp5*=A1;
00174 
00175         z11= tmp7 + tmp5;
00176         z13= tmp7 - tmp5;
00177 
00178         data[8*5 + i]= lrintf(SCALE(8*5 + i) * (z13 + z2));
00179         data[8*3 + i]= lrintf(SCALE(8*3 + i) * (z13 - z2));
00180         data[8*1 + i]= lrintf(SCALE(8*1 + i) * (z11 + z4));
00181         data[8*7 + i]= lrintf(SCALE(8*7 + i) * (z11 - z4));
00182     }
00183 }
00184 
00185 void ff_faandct248(DCTELEM * data)
00186 {
00187     FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
00188     FLOAT tmp10, tmp11, tmp12, tmp13;
00189     FLOAT temp[64];
00190     int i;
00191 
00192     emms_c();
00193 
00194     row_fdct(temp, data);
00195 
00196     for (i=0; i<8; i++) {
00197         tmp0 = temp[8*0 + i] + temp[8*1 + i];
00198         tmp1 = temp[8*2 + i] + temp[8*3 + i];
00199         tmp2 = temp[8*4 + i] + temp[8*5 + i];
00200         tmp3 = temp[8*6 + i] + temp[8*7 + i];
00201         tmp4 = temp[8*0 + i] - temp[8*1 + i];
00202         tmp5 = temp[8*2 + i] - temp[8*3 + i];
00203         tmp6 = temp[8*4 + i] - temp[8*5 + i];
00204         tmp7 = temp[8*6 + i] - temp[8*7 + i];
00205 
00206         tmp10 = tmp0 + tmp3;
00207         tmp11 = tmp1 + tmp2;
00208         tmp12 = tmp1 - tmp2;
00209         tmp13 = tmp0 - tmp3;
00210 
00211         data[8*0 + i] = lrintf(SCALE(8*0 + i) * (tmp10 + tmp11));
00212         data[8*4 + i] = lrintf(SCALE(8*4 + i) * (tmp10 - tmp11));
00213 
00214         tmp12 += tmp13;
00215         tmp12 *= A1;
00216         data[8*2 + i] = lrintf(SCALE(8*2 + i) * (tmp13 + tmp12));
00217         data[8*6 + i] = lrintf(SCALE(8*6 + i) * (tmp13 - tmp12));
00218 
00219         tmp10 = tmp4 + tmp7;
00220         tmp11 = tmp5 + tmp6;
00221         tmp12 = tmp5 - tmp6;
00222         tmp13 = tmp4 - tmp7;
00223 
00224         data[8*1 + i] = lrintf(SCALE(8*0 + i) * (tmp10 + tmp11));
00225         data[8*5 + i] = lrintf(SCALE(8*4 + i) * (tmp10 - tmp11));
00226 
00227         tmp12 += tmp13;
00228         tmp12 *= A1;
00229         data[8*3 + i] = lrintf(SCALE(8*2 + i) * (tmp13 + tmp12));
00230         data[8*7 + i] = lrintf(SCALE(8*6 + i) * (tmp13 - tmp12));
00231     }
00232 }