Xash3D FWGS engine.
 
 
 
 

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4.4 KiB

/*
dct64.c: DCT64, the plain C version
copyright ?-2006 by the mpg123 project - free software under the terms of the LGPL 2.1
see COPYING and AUTHORS files in distribution or http://mpg123.org
initially written by Michael Hipp
*/
/*
* Discrete Cosine Transform (DCT) for subband synthesis
*
* -funroll-loops (for gcc) will remove the loops for better performance
* using loops in the source-code enhances readabillity
*
*/
#include "mpg123.h"
void dct64( float *out0, float *out1, float *samples )
{
float bufs[64];
{
register float *b1, *b2, *bs;
register float *costab;
register int i, j;
b1 = samples;
bs = bufs;
costab = pnts[0]+16;
b2 = b1 + 32;
for( i = 15; i >= 0; i-- )
*bs++ = (*b1++ + *--b2);
for( i = 15; i >= 0; i-- )
*bs++ = REAL_MUL((*--b2 - *b1++), *--costab);
b1 = bufs;
costab = pnts[1] + 8;
b2 = b1 + 16;
{
for( i = 7; i >= 0; i-- )
*bs++ = (*b1++ + *--b2);
for( i = 7; i >= 0; i-- )
*bs++ = REAL_MUL((*--b2 - *b1++), *--costab);
b2 += 32;
costab += 8;
for( i = 7; i >= 0; i-- )
*bs++ = (*b1++ + *--b2);
for( i = 7; i >= 0; i-- )
*bs++ = REAL_MUL((*b1++ - *--b2), *--costab);
b2 += 32;
}
bs = bufs;
costab = pnts[2];
b2 = b1 + 8;
for( j = 2; j; j-- )
{
for( i = 3; i >= 0; i-- )
*bs++ = (*b1++ + *--b2);
for( i = 3;i >= 0; i-- )
*bs++ = REAL_MUL((*--b2 - *b1++), costab[i]);
b2 += 16;
for( i = 3; i >= 0; i-- )
*bs++ = (*b1++ + *--b2);
for( i = 3;i >= 0; i-- )
*bs++ = REAL_MUL((*b1++ - *--b2), costab[i]);
b2 += 16;
}
b1 = bufs;
costab = pnts[3];
b2 = b1 + 4;
for( j = 4; j; j-- )
{
*bs++ = (*b1++ + *--b2);
*bs++ = (*b1++ + *--b2);
*bs++ = REAL_MUL((*--b2 - *b1++), costab[1]);
*bs++ = REAL_MUL((*--b2 - *b1++), costab[0]);
b2 += 8;
*bs++ = (*b1++ + *--b2);
*bs++ = (*b1++ + *--b2);
*bs++ = REAL_MUL((*b1++ - *--b2), costab[1]);
*bs++ = REAL_MUL((*b1++ - *--b2), costab[0]);
b2 += 8;
}
bs = bufs;
costab = pnts[4];
for( j = 8; j; j-- )
{
float v0, v1;
v0 = *b1++;
v1 = *b1++;
*bs++ = (v0 + v1);
*bs++ = REAL_MUL((v0 - v1), (*costab));
v0 = *b1++;
v1 = *b1++;
*bs++ = (v0 + v1);
*bs++ = REAL_MUL((v1 - v0), (*costab));
}
}
{
register float *b1;
register int i;
for( b1 =bufs, i = 8; i; i--, b1 += 4 )
b1[2] += b1[3];
for( b1 = bufs, i = 4; i; i--, b1 += 8 )
{
b1[4] += b1[6];
b1[6] += b1[5];
b1[5] += b1[7];
}
for( b1 = bufs, i = 2; i; i--, b1 += 16 )
{
b1[8] += b1[12];
b1[12] += b1[10];
b1[10] += b1[14];
b1[14] += b1[9];
b1[9] += b1[13];
b1[13] += b1[11];
b1[11] += b1[15];
}
}
out0[0x10*16] = REAL_SCALE_DCT64( bufs[0] );
out0[0x10*15] = REAL_SCALE_DCT64( bufs[16+0] + bufs[16+8] );
out0[0x10*14] = REAL_SCALE_DCT64( bufs[8] );
out0[0x10*13] = REAL_SCALE_DCT64( bufs[16+8] + bufs[16+4] );
out0[0x10*12] = REAL_SCALE_DCT64( bufs[4] );
out0[0x10*11] = REAL_SCALE_DCT64( bufs[16+4] + bufs[16+12] );
out0[0x10*10] = REAL_SCALE_DCT64( bufs[12] );
out0[0x10* 9] = REAL_SCALE_DCT64( bufs[16+12] + bufs[16+2] );
out0[0x10* 8] = REAL_SCALE_DCT64( bufs[2] );
out0[0x10* 7] = REAL_SCALE_DCT64( bufs[16+2] + bufs[16+10] );
out0[0x10* 6] = REAL_SCALE_DCT64( bufs[10] );
out0[0x10* 5] = REAL_SCALE_DCT64( bufs[16+10] + bufs[16+6] );
out0[0x10* 4] = REAL_SCALE_DCT64( bufs[6] );
out0[0x10* 3] = REAL_SCALE_DCT64( bufs[16+6] + bufs[16+14] );
out0[0x10* 2] = REAL_SCALE_DCT64( bufs[14] );
out0[0x10* 1] = REAL_SCALE_DCT64( bufs[16+14] + bufs[16+1] );
out0[0x10* 0] = REAL_SCALE_DCT64( bufs[1] );
out1[0x10* 0] = REAL_SCALE_DCT64( bufs[1] );
out1[0x10* 1] = REAL_SCALE_DCT64( bufs[16+1] + bufs[16+9] );
out1[0x10* 2] = REAL_SCALE_DCT64( bufs[9] );
out1[0x10* 3] = REAL_SCALE_DCT64( bufs[16+9] + bufs[16+5] );
out1[0x10* 4] = REAL_SCALE_DCT64( bufs[5] );
out1[0x10* 5] = REAL_SCALE_DCT64( bufs[16+5] + bufs[16+13] );
out1[0x10* 6] = REAL_SCALE_DCT64( bufs[13] );
out1[0x10* 7] = REAL_SCALE_DCT64( bufs[16+13] + bufs[16+3] );
out1[0x10* 8] = REAL_SCALE_DCT64( bufs[3] );
out1[0x10* 9] = REAL_SCALE_DCT64( bufs[16+3] + bufs[16+11] );
out1[0x10*10] = REAL_SCALE_DCT64( bufs[11] );
out1[0x10*11] = REAL_SCALE_DCT64( bufs[16+11] + bufs[16+7] );
out1[0x10*12] = REAL_SCALE_DCT64( bufs[7] );
out1[0x10*13] = REAL_SCALE_DCT64( bufs[16+7] + bufs[16+15] );
out1[0x10*14] = REAL_SCALE_DCT64( bufs[15] );
out1[0x10*15] = REAL_SCALE_DCT64( bufs[16+15] );
}