jedi-academy/codemp/mp3code/csbt.c
2013-04-23 15:21:39 +10:00

355 lines
10 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 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: csbt.c,v 1.2 1999/10/19 07:13:08 elrod Exp $
____________________________________________________________________________*/
/**** csbt.c ***************************************************
MPEG audio decoder, dct and window
portable C
1/7/96 mod for Layer III
******************************************************************/
#include <stdlib.h>
#include <stdio.h>
#include <float.h>
#include <math.h>
void fdct32(float *, float *);
void fdct32_dual(float *, float *);
void fdct32_dual_mono(float *, float *);
void fdct16(float *, float *);
void fdct16_dual(float *, float *);
void fdct16_dual_mono(float *, float *);
void fdct8(float *, float *);
void fdct8_dual(float *, float *);
void fdct8_dual_mono(float *, float *);
void window(float *vbuf, int vb_ptr, short *pcm);
void window_dual(float *vbuf, int vb_ptr, short *pcm);
void window16(float *vbuf, int vb_ptr, short *pcm);
void window16_dual(float *vbuf, int vb_ptr, short *pcm);
void window8(float *vbuf, int vb_ptr, short *pcm);
void window8_dual(float *vbuf, int vb_ptr, short *pcm);
/*-------------------------------------------------------------------------*/
/* circular window buffers */
#include "mp3struct.h"
////static signed int vb_ptr; // !!!!!!!!!!!!!
////static signed int vb2_ptr; // !!!!!!!!!!!!!
////static float pMP3Stream->vbuf[512]; // !!!!!!!!!!!!!
////static float vbuf2[512]; // !!!!!!!!!!!!!
float *dct_coef_addr();
/*======================================================================*/
static void gencoef() /* gen coef for N=32 (31 coefs) */
{
static int iOnceOnly = 0;
int p, n, i, k;
double t, pi;
float *coef32;
if (!iOnceOnly++)
{
coef32 = dct_coef_addr();
pi = 4.0 * atan(1.0);
n = 16;
k = 0;
for (i = 0; i < 5; i++, n = n / 2)
{
for (p = 0; p < n; p++, k++)
{
t = (pi / (4 * n)) * (2 * p + 1);
coef32[k] = (float) (0.50 / cos(t));
}
}
}
}
/*------------------------------------------------------------*/
void sbt_init()
{
int i;
static int first_pass = 1;
if (first_pass)
{
gencoef();
first_pass = 0;
}
/* clear window pMP3Stream->vbuf */
for (i = 0; i < 512; i++)
{
pMP3Stream->vbuf[i] = 0.0F;
pMP3Stream->vbuf2[i] = 0.0F;
}
pMP3Stream->vb2_ptr = pMP3Stream->vb_ptr = 0;
}
/*============================================================*/
/*============================================================*/
/*============================================================*/
void sbt_mono(float *sample, short *pcm, int n)
{
int i;
for (i = 0; i < n; i++)
{
fdct32(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
window(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
sample += 64;
pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 32) & 511;
pcm += 32;
}
}
/*------------------------------------------------------------*/
void sbt_dual(float *sample, short *pcm, int n)
{
int i;
for (i = 0; i < n; i++)
{
fdct32_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
fdct32_dual(sample + 1, pMP3Stream->vbuf2 + pMP3Stream->vb_ptr);
window_dual(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
window_dual(pMP3Stream->vbuf2, pMP3Stream->vb_ptr, pcm + 1);
sample += 64;
pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 32) & 511;
pcm += 64;
}
}
/*------------------------------------------------------------*/
/* convert dual to mono */
void sbt_dual_mono(float *sample, short *pcm, int n)
{
int i;
for (i = 0; i < n; i++)
{
fdct32_dual_mono(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
window(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
sample += 64;
pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 32) & 511;
pcm += 32;
}
}
/*------------------------------------------------------------*/
/* convert dual to left */
void sbt_dual_left(float *sample, short *pcm, int n)
{
int i;
for (i = 0; i < n; i++)
{
fdct32_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
window(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
sample += 64;
pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 32) & 511;
pcm += 32;
}
}
/*------------------------------------------------------------*/
/* convert dual to right */
void sbt_dual_right(float *sample, short *pcm, int n)
{
int i;
sample++; /* point to right chan */
for (i = 0; i < n; i++)
{
fdct32_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
window(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
sample += 64;
pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 32) & 511;
pcm += 32;
}
}
/*------------------------------------------------------------*/
/*---------------- 16 pt sbt's -------------------------------*/
/*------------------------------------------------------------*/
void sbt16_mono(float *sample, short *pcm, int n)
{
int i;
for (i = 0; i < n; i++)
{
fdct16(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
window16(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
sample += 64;
pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 16) & 255;
pcm += 16;
}
}
/*------------------------------------------------------------*/
void sbt16_dual(float *sample, short *pcm, int n)
{
int i;
for (i = 0; i < n; i++)
{
fdct16_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
fdct16_dual(sample + 1, pMP3Stream->vbuf2 + pMP3Stream->vb_ptr);
window16_dual(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
window16_dual(pMP3Stream->vbuf2, pMP3Stream->vb_ptr, pcm + 1);
sample += 64;
pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 16) & 255;
pcm += 32;
}
}
/*------------------------------------------------------------*/
void sbt16_dual_mono(float *sample, short *pcm, int n)
{
int i;
for (i = 0; i < n; i++)
{
fdct16_dual_mono(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
window16(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
sample += 64;
pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 16) & 255;
pcm += 16;
}
}
/*------------------------------------------------------------*/
void sbt16_dual_left(float *sample, short *pcm, int n)
{
int i;
for (i = 0; i < n; i++)
{
fdct16_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
window16(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
sample += 64;
pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 16) & 255;
pcm += 16;
}
}
/*------------------------------------------------------------*/
void sbt16_dual_right(float *sample, short *pcm, int n)
{
int i;
sample++;
for (i = 0; i < n; i++)
{
fdct16_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
window16(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
sample += 64;
pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 16) & 255;
pcm += 16;
}
}
/*------------------------------------------------------------*/
/*---------------- 8 pt sbt's -------------------------------*/
/*------------------------------------------------------------*/
void sbt8_mono(float *sample, short *pcm, int n)
{
int i;
for (i = 0; i < n; i++)
{
fdct8(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
window8(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
sample += 64;
pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 8) & 127;
pcm += 8;
}
}
/*------------------------------------------------------------*/
void sbt8_dual(float *sample, short *pcm, int n)
{
int i;
for (i = 0; i < n; i++)
{
fdct8_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
fdct8_dual(sample + 1, pMP3Stream->vbuf2 + pMP3Stream->vb_ptr);
window8_dual(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
window8_dual(pMP3Stream->vbuf2, pMP3Stream->vb_ptr, pcm + 1);
sample += 64;
pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 8) & 127;
pcm += 16;
}
}
/*------------------------------------------------------------*/
void sbt8_dual_mono(float *sample, short *pcm, int n)
{
int i;
for (i = 0; i < n; i++)
{
fdct8_dual_mono(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
window8(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
sample += 64;
pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 8) & 127;
pcm += 8;
}
}
/*------------------------------------------------------------*/
void sbt8_dual_left(float *sample, short *pcm, int n)
{
int i;
for (i = 0; i < n; i++)
{
fdct8_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
window8(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
sample += 64;
pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 8) & 127;
pcm += 8;
}
}
/*------------------------------------------------------------*/
void sbt8_dual_right(float *sample, short *pcm, int n)
{
int i;
sample++;
for (i = 0; i < n; i++)
{
fdct8_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
window8(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
sample += 64;
pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 8) & 127;
pcm += 8;
}
}
/*------------------------------------------------------------*/
/*------------------------------------------------------------*/
#define COMPILE_ME
#include "csbtb.c" /* 8 bit output */
#include "csbtL3.c" /* Layer III */
/*------------------------------------------------------------*/