mirror of
https://github.com/ioquake/jedi-academy.git
synced 2024-11-28 15:02:42 +00:00
320 lines
8.8 KiB
C
320 lines
8.8 KiB
C
/*____________________________________________________________________________
|
|
|
|
FreeAmp - The Free MP3 Player
|
|
|
|
MP3 Decoder originally Copyright (C) 1995-1997 Xing Technology
|
|
Corp. http://www.xingtech.com
|
|
|
|
Portions Copyright (C) 1998-1999 EMusic.com
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program 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 General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
|
|
$Id: cdct.c,v 1.11 1999/10/19 07:13:08 elrod Exp $
|
|
____________________________________________________________________________*/
|
|
|
|
/**** cdct.c ***************************************************
|
|
|
|
mod 5/16/95 first stage in 8 pt dct does not drop last sb mono
|
|
|
|
|
|
MPEG audio decoder, dct
|
|
portable C
|
|
|
|
******************************************************************/
|
|
|
|
#include "config.h"
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <float.h>
|
|
#include <math.h>
|
|
|
|
#pragma warning ( disable : 4711 ) // function 'xxxx' selected for automatic inline expansion
|
|
|
|
float coef32[31]; /* 32 pt dct coefs */ // !!!!!!!!!!!!!!!!!! (only generated once (always to same value)
|
|
|
|
/*------------------------------------------------------------*/
|
|
float *dct_coef_addr()
|
|
{
|
|
return coef32;
|
|
}
|
|
/*------------------------------------------------------------*/
|
|
static void forward_bf(int m, int n, float x[], float f[], float coef[])
|
|
{
|
|
int i, j, n2;
|
|
int p, q, p0, k;
|
|
|
|
p0 = 0;
|
|
n2 = n >> 1;
|
|
for (i = 0; i < m; i++, p0 += n)
|
|
{
|
|
k = 0;
|
|
p = p0;
|
|
q = p + n - 1;
|
|
for (j = 0; j < n2; j++, p++, q--, k++)
|
|
{
|
|
f[p] = x[p] + x[q];
|
|
f[n2 + p] = coef[k] * (x[p] - x[q]);
|
|
}
|
|
}
|
|
}
|
|
/*------------------------------------------------------------*/
|
|
static void back_bf(int m, int n, float x[], float f[])
|
|
{
|
|
int i, j, n2, n21;
|
|
int p, q, p0;
|
|
|
|
p0 = 0;
|
|
n2 = n >> 1;
|
|
n21 = n2 - 1;
|
|
for (i = 0; i < m; i++, p0 += n)
|
|
{
|
|
p = p0;
|
|
q = p0;
|
|
for (j = 0; j < n2; j++, p += 2, q++)
|
|
f[p] = x[q];
|
|
p = p0 + 1;
|
|
for (j = 0; j < n21; j++, p += 2, q++)
|
|
f[p] = x[q] + x[q + 1];
|
|
f[p] = x[q];
|
|
}
|
|
}
|
|
/*------------------------------------------------------------*/
|
|
|
|
|
|
void fdct32(float x[], float c[])
|
|
{
|
|
float a[32]; /* ping pong buffers */
|
|
float b[32];
|
|
int p, q;
|
|
|
|
float *src = x;
|
|
|
|
/* special first stage */
|
|
for (p = 0, q = 31; p < 16; p++, q--)
|
|
{
|
|
a[p] = src[p] + src[q];
|
|
a[16 + p] = coef32[p] * (src[p] - src[q]);
|
|
}
|
|
forward_bf(2, 16, a, b, coef32 + 16);
|
|
forward_bf(4, 8, b, a, coef32 + 16 + 8);
|
|
forward_bf(8, 4, a, b, coef32 + 16 + 8 + 4);
|
|
forward_bf(16, 2, b, a, coef32 + 16 + 8 + 4 + 2);
|
|
back_bf(8, 4, a, b);
|
|
back_bf(4, 8, b, a);
|
|
back_bf(2, 16, a, b);
|
|
back_bf(1, 32, b, c);
|
|
}
|
|
/*------------------------------------------------------------*/
|
|
void fdct32_dual(float x[], float c[])
|
|
{
|
|
float a[32]; /* ping pong buffers */
|
|
float b[32];
|
|
int p, pp, qq;
|
|
|
|
/* special first stage for dual chan (interleaved x) */
|
|
pp = 0;
|
|
qq = 2 * 31;
|
|
for (p = 0; p < 16; p++, pp += 2, qq -= 2)
|
|
{
|
|
a[p] = x[pp] + x[qq];
|
|
a[16 + p] = coef32[p] * (x[pp] - x[qq]);
|
|
}
|
|
forward_bf(2, 16, a, b, coef32 + 16);
|
|
forward_bf(4, 8, b, a, coef32 + 16 + 8);
|
|
forward_bf(8, 4, a, b, coef32 + 16 + 8 + 4);
|
|
forward_bf(16, 2, b, a, coef32 + 16 + 8 + 4 + 2);
|
|
back_bf(8, 4, a, b);
|
|
back_bf(4, 8, b, a);
|
|
back_bf(2, 16, a, b);
|
|
back_bf(1, 32, b, c);
|
|
}
|
|
/*---------------convert dual to mono------------------------------*/
|
|
void fdct32_dual_mono(float x[], float c[])
|
|
{
|
|
float a[32]; /* ping pong buffers */
|
|
float b[32];
|
|
float t1, t2;
|
|
int p, pp, qq;
|
|
|
|
/* special first stage */
|
|
pp = 0;
|
|
qq = 2 * 31;
|
|
for (p = 0; p < 16; p++, pp += 2, qq -= 2)
|
|
{
|
|
t1 = 0.5F * (x[pp] + x[pp + 1]);
|
|
t2 = 0.5F * (x[qq] + x[qq + 1]);
|
|
a[p] = t1 + t2;
|
|
a[16 + p] = coef32[p] * (t1 - t2);
|
|
}
|
|
forward_bf(2, 16, a, b, coef32 + 16);
|
|
forward_bf(4, 8, b, a, coef32 + 16 + 8);
|
|
forward_bf(8, 4, a, b, coef32 + 16 + 8 + 4);
|
|
forward_bf(16, 2, b, a, coef32 + 16 + 8 + 4 + 2);
|
|
back_bf(8, 4, a, b);
|
|
back_bf(4, 8, b, a);
|
|
back_bf(2, 16, a, b);
|
|
back_bf(1, 32, b, c);
|
|
}
|
|
/*------------------------------------------------------------*/
|
|
/*---------------- 16 pt fdct -------------------------------*/
|
|
void fdct16(float x[], float c[])
|
|
{
|
|
float a[16]; /* ping pong buffers */
|
|
float b[16];
|
|
int p, q;
|
|
|
|
/* special first stage (drop highest sb) */
|
|
a[0] = x[0];
|
|
a[8] = coef32[16] * x[0];
|
|
for (p = 1, q = 14; p < 8; p++, q--)
|
|
{
|
|
a[p] = x[p] + x[q];
|
|
a[8 + p] = coef32[16 + p] * (x[p] - x[q]);
|
|
}
|
|
forward_bf(2, 8, a, b, coef32 + 16 + 8);
|
|
forward_bf(4, 4, b, a, coef32 + 16 + 8 + 4);
|
|
forward_bf(8, 2, a, b, coef32 + 16 + 8 + 4 + 2);
|
|
back_bf(4, 4, b, a);
|
|
back_bf(2, 8, a, b);
|
|
back_bf(1, 16, b, c);
|
|
}
|
|
/*------------------------------------------------------------*/
|
|
/*---------------- 16 pt fdct dual chan---------------------*/
|
|
void fdct16_dual(float x[], float c[])
|
|
{
|
|
float a[16]; /* ping pong buffers */
|
|
float b[16];
|
|
int p, pp, qq;
|
|
|
|
/* special first stage for interleaved input */
|
|
a[0] = x[0];
|
|
a[8] = coef32[16] * x[0];
|
|
pp = 2;
|
|
qq = 2 * 14;
|
|
for (p = 1; p < 8; p++, pp += 2, qq -= 2)
|
|
{
|
|
a[p] = x[pp] + x[qq];
|
|
a[8 + p] = coef32[16 + p] * (x[pp] - x[qq]);
|
|
}
|
|
forward_bf(2, 8, a, b, coef32 + 16 + 8);
|
|
forward_bf(4, 4, b, a, coef32 + 16 + 8 + 4);
|
|
forward_bf(8, 2, a, b, coef32 + 16 + 8 + 4 + 2);
|
|
back_bf(4, 4, b, a);
|
|
back_bf(2, 8, a, b);
|
|
back_bf(1, 16, b, c);
|
|
}
|
|
/*------------------------------------------------------------*/
|
|
/*---------------- 16 pt fdct dual to mono-------------------*/
|
|
void fdct16_dual_mono(float x[], float c[])
|
|
{
|
|
float a[16]; /* ping pong buffers */
|
|
float b[16];
|
|
float t1, t2;
|
|
int p, pp, qq;
|
|
|
|
/* special first stage */
|
|
a[0] = 0.5F * (x[0] + x[1]);
|
|
a[8] = coef32[16] * a[0];
|
|
pp = 2;
|
|
qq = 2 * 14;
|
|
for (p = 1; p < 8; p++, pp += 2, qq -= 2)
|
|
{
|
|
t1 = 0.5F * (x[pp] + x[pp + 1]);
|
|
t2 = 0.5F * (x[qq] + x[qq + 1]);
|
|
a[p] = t1 + t2;
|
|
a[8 + p] = coef32[16 + p] * (t1 - t2);
|
|
}
|
|
forward_bf(2, 8, a, b, coef32 + 16 + 8);
|
|
forward_bf(4, 4, b, a, coef32 + 16 + 8 + 4);
|
|
forward_bf(8, 2, a, b, coef32 + 16 + 8 + 4 + 2);
|
|
back_bf(4, 4, b, a);
|
|
back_bf(2, 8, a, b);
|
|
back_bf(1, 16, b, c);
|
|
}
|
|
/*------------------------------------------------------------*/
|
|
/*---------------- 8 pt fdct -------------------------------*/
|
|
void fdct8(float x[], float c[])
|
|
{
|
|
float a[8]; /* ping pong buffers */
|
|
float b[8];
|
|
int p, q;
|
|
|
|
/* special first stage */
|
|
|
|
b[0] = x[0] + x[7];
|
|
b[4] = coef32[16 + 8] * (x[0] - x[7]);
|
|
for (p = 1, q = 6; p < 4; p++, q--)
|
|
{
|
|
b[p] = x[p] + x[q];
|
|
b[4 + p] = coef32[16 + 8 + p] * (x[p] - x[q]);
|
|
}
|
|
|
|
forward_bf(2, 4, b, a, coef32 + 16 + 8 + 4);
|
|
forward_bf(4, 2, a, b, coef32 + 16 + 8 + 4 + 2);
|
|
back_bf(2, 4, b, a);
|
|
back_bf(1, 8, a, c);
|
|
}
|
|
/*------------------------------------------------------------*/
|
|
/*---------------- 8 pt fdct dual chan---------------------*/
|
|
void fdct8_dual(float x[], float c[])
|
|
{
|
|
float a[8]; /* ping pong buffers */
|
|
float b[8];
|
|
int p, pp, qq;
|
|
|
|
/* special first stage for interleaved input */
|
|
b[0] = x[0] + x[14];
|
|
b[4] = coef32[16 + 8] * (x[0] - x[14]);
|
|
pp = 2;
|
|
qq = 2 * 6;
|
|
for (p = 1; p < 4; p++, pp += 2, qq -= 2)
|
|
{
|
|
b[p] = x[pp] + x[qq];
|
|
b[4 + p] = coef32[16 + 8 + p] * (x[pp] - x[qq]);
|
|
}
|
|
forward_bf(2, 4, b, a, coef32 + 16 + 8 + 4);
|
|
forward_bf(4, 2, a, b, coef32 + 16 + 8 + 4 + 2);
|
|
back_bf(2, 4, b, a);
|
|
back_bf(1, 8, a, c);
|
|
}
|
|
/*------------------------------------------------------------*/
|
|
/*---------------- 8 pt fdct dual to mono---------------------*/
|
|
void fdct8_dual_mono(float x[], float c[])
|
|
{
|
|
float a[8]; /* ping pong buffers */
|
|
float b[8];
|
|
float t1, t2;
|
|
int p, pp, qq;
|
|
|
|
/* special first stage */
|
|
t1 = 0.5F * (x[0] + x[1]);
|
|
t2 = 0.5F * (x[14] + x[15]);
|
|
b[0] = t1 + t2;
|
|
b[4] = coef32[16 + 8] * (t1 - t2);
|
|
pp = 2;
|
|
qq = 2 * 6;
|
|
for (p = 1; p < 4; p++, pp += 2, qq -= 2)
|
|
{
|
|
t1 = 0.5F * (x[pp] + x[pp + 1]);
|
|
t2 = 0.5F * (x[qq] + x[qq + 1]);
|
|
b[p] = t1 + t2;
|
|
b[4 + p] = coef32[16 + 8 + p] * (t1 - t2);
|
|
}
|
|
forward_bf(2, 4, b, a, coef32 + 16 + 8 + 4);
|
|
forward_bf(4, 2, a, b, coef32 + 16 + 8 + 4 + 2);
|
|
back_bf(2, 4, b, a);
|
|
back_bf(1, 8, a, c);
|
|
}
|
|
/*------------------------------------------------------------*/
|