From 65e4c8c919c63b947b157bdb8f141685b6553fba Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 22 Oct 2003 18:26:38 +0000 Subject: floating point AAN DCT Originally committed as revision 2415 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/faandct.c | 156 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 156 insertions(+) create mode 100644 libavcodec/faandct.c (limited to 'libavcodec/faandct.c') diff --git a/libavcodec/faandct.c b/libavcodec/faandct.c new file mode 100644 index 0000000000..c7388fb4de --- /dev/null +++ b/libavcodec/faandct.c @@ -0,0 +1,156 @@ +/* + * Floating point AAN DCT + * Copyright (c) 2003 Michael Niedermayer + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +/** + * @file faandct.c + * @brief + * Floating point AAN DCT + * @author Michael Niedermayer + */ + +#include + +#include "dsputil.h" +#include "faandct.h" + +#define FLOAT float + +//numbers generated by simple c code (not as accurate as they could be) +/* +for(i=0; i<8; i++){ + printf("#define B%d %1.20llf\n", i, (long double)1.0/(cosl(i*acosl(-1.0)/(long double)16.0)*sqrtl(2))); +} +*/ +#define B0 1.00000000000000000000 +#define B1 0.72095982200694791383 // (cos(pi*1/16)sqrt(2))^-1 +#define B2 0.76536686473017954350 // (cos(pi*2/16)sqrt(2))^-1 +#define B3 0.85043009476725644878 // (cos(pi*3/16)sqrt(2))^-1 +#define B4 1.00000000000000000000 // (cos(pi*4/16)sqrt(2))^-1 +#define B5 1.27275858057283393842 // (cos(pi*5/16)sqrt(2))^-1 +#define B6 1.84775906502257351242 // (cos(pi*6/16)sqrt(2))^-1 +#define B7 3.62450978541155137218 // (cos(pi*7/16)sqrt(2))^-1 + + +#define A1 0.70710678118654752438 // cos(pi*4/16) +#define A2 0.54119610014619698435 // cos(pi*6/16)sqrt(2) +#define A5 0.38268343236508977170 // cos(pi*6/16) +#define A4 1.30656296487637652774 // cos(pi*2/16)sqrt(2) + +static FLOAT postscale[64]={ +B0*B0, B0*B1, B0*B2, B0*B3, B0*B4, B0*B5, B0*B6, B0*B7, +B1*B0, B1*B1, B1*B2, B1*B3, B1*B4, B1*B5, B1*B6, B1*B7, +B2*B0, B2*B1, B2*B2, B2*B3, B2*B4, B2*B5, B2*B6, B2*B7, +B3*B0, B3*B1, B3*B2, B3*B3, B3*B4, B3*B5, B3*B6, B3*B7, +B4*B0, B4*B1, B4*B2, B4*B3, B4*B4, B4*B5, B4*B6, B4*B7, +B5*B0, B5*B1, B5*B2, B5*B3, B5*B4, B5*B5, B5*B6, B5*B7, +B6*B0, B6*B1, B6*B2, B6*B3, B6*B4, B6*B5, B6*B6, B6*B7, +B7*B0, B7*B1, B7*B2, B7*B3, B7*B4, B7*B5, B7*B6, B7*B7, +}; + +void ff_faandct(DCTELEM * data) +{ + FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7; + FLOAT tmp10, tmp11, tmp12, tmp13; + FLOAT z1, z2, z3, z4, z5, z11, z13; + FLOAT temp[64]; + int i; + + emms(); + + for (i=0; i<8*8; i+=8) { + tmp0= data[0 + i] + data[7 + i]; + tmp7= data[0 + i] - data[7 + i]; + tmp1= data[1 + i] + data[6 + i]; + tmp6= data[1 + i] - data[6 + i]; + tmp2= data[2 + i] + data[5 + i]; + tmp5= data[2 + i] - data[5 + i]; + tmp3= data[3 + i] + data[4 + i]; + tmp4= data[3 + i] - data[4 + i]; + + tmp10= tmp0 + tmp3; + tmp13= tmp0 - tmp3; + tmp11= tmp1 + tmp2; + tmp12= tmp1 - tmp2; + + temp[0 + i]= tmp10 + tmp11; + temp[4 + i]= tmp10 - tmp11; + + z1= (tmp12 + tmp13)*A1; + temp[2 + i]= tmp13 + z1; + temp[6 + i]= tmp13 - z1; + + tmp10= tmp4 + tmp5; + tmp11= tmp5 + tmp6; + tmp12= tmp6 + tmp7; + + z5= (tmp10 - tmp12) * A5; + z2= tmp10*A2 + z5; + z4= tmp12*A4 + z5; + z3= tmp11*A1; + + z11= tmp7 + z3; + z13= tmp7 - z3; + + temp[5 + i]= z13 + z2; + temp[3 + i]= z13 - z2; + temp[1 + i]= z11 + z4; + temp[7 + i]= z11 - z4; + } + + for (i=0; i<8; i++) { + tmp0= temp[8*0 + i] + temp[8*7 + i]; + tmp7= temp[8*0 + i] - temp[8*7 + i]; + tmp1= temp[8*1 + i] + temp[8*6 + i]; + tmp6= temp[8*1 + i] - temp[8*6 + i]; + tmp2= temp[8*2 + i] + temp[8*5 + i]; + tmp5= temp[8*2 + i] - temp[8*5 + i]; + tmp3= temp[8*3 + i] + temp[8*4 + i]; + tmp4= temp[8*3 + i] - temp[8*4 + i]; + + tmp10= tmp0 + tmp3; + tmp13= tmp0 - tmp3; + tmp11= tmp1 + tmp2; + tmp12= tmp1 - tmp2; + + data[8*0 + i]= lrint(postscale[8*0 + i] * (tmp10 + tmp11)); + data[8*4 + i]= lrint(postscale[8*4 + i] * (tmp10 - tmp11)); + + z1= (tmp12 + tmp13)* A1; + data[8*2 + i]= lrint(postscale[8*2 + i] * (tmp13 + z1)); + data[8*6 + i]= lrint(postscale[8*6 + i] * (tmp13 - z1)); + + tmp10= tmp4 + tmp5; + tmp11= tmp5 + tmp6; + tmp12= tmp6 + tmp7; + + z5= (tmp10 - tmp12) * A5; + z2= tmp10*A2 + z5; + z4= tmp12*A4 + z5; + z3= tmp11*A1; + + z11= tmp7 + z3; + z13= tmp7 - z3; + + data[8*5 + i]= lrint(postscale[8*5 + i] * (z13 + z2)); + data[8*3 + i]= lrint(postscale[8*3 + i] * (z13 - z2)); + data[8*1 + i]= lrint(postscale[8*1 + i] * (z11 + z4)); + data[8*7 + i]= lrint(postscale[8*7 + i] * (z11 - z4)); + } +} -- cgit v1.2.3