jediacademy/code/mp3code/cwin.c
2013-04-04 17:35:38 -05:00

470 lines
10 KiB
C

#pragma warning(disable:4206) // nonstandard extension used : translation unit is empty
#ifdef COMPILE_ME
/*____________________________________________________________________________
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: cwin.c,v 1.7 1999/10/19 07:13:08 elrod Exp $
____________________________________________________________________________*/
/**** cwin.c ***************************************************
include to cwinm.c
MPEG audio decoder, float window routines
portable C
******************************************************************/
#include "config.h"
/*-------------------------------------------------------------------------*/
void window(float *vbuf, int vb_ptr, short *pcm)
{
int i, j;
int si, bx;
const float *coef;
float sum;
long tmp;
si = vb_ptr + 16;
bx = (si + 32) & 511;
coef = wincoef;
/*-- first 16 --*/
for (i = 0; i < 16; i++)
{
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef++) * vbuf[si];
si = (si + 64) & 511;
sum -= (*coef++) * vbuf[bx];
bx = (bx + 64) & 511;
}
si++;
bx--;
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm++ = tmp;
}
/*-- special case --*/
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef++) * vbuf[bx];
bx = (bx + 64) & 511;
}
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm++ = tmp;
/*-- last 15 --*/
coef = wincoef + 255; /* back pass through coefs */
for (i = 0; i < 15; i++)
{
si--;
bx++;
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef--) * vbuf[si];
si = (si + 64) & 511;
sum += (*coef--) * vbuf[bx];
bx = (bx + 64) & 511;
}
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm++ = tmp;
}
}
/*------------------------------------------------------------*/
void window_dual(float *vbuf, int vb_ptr, short *pcm)
{
int i, j; /* dual window interleaves output */
int si, bx;
const float *coef;
float sum;
long tmp;
si = vb_ptr + 16;
bx = (si + 32) & 511;
coef = wincoef;
/*-- first 16 --*/
for (i = 0; i < 16; i++)
{
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef++) * vbuf[si];
si = (si + 64) & 511;
sum -= (*coef++) * vbuf[bx];
bx = (bx + 64) & 511;
}
si++;
bx--;
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm = tmp;
pcm += 2;
}
/*-- special case --*/
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef++) * vbuf[bx];
bx = (bx + 64) & 511;
}
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm = tmp;
pcm += 2;
/*-- last 15 --*/
coef = wincoef + 255; /* back pass through coefs */
for (i = 0; i < 15; i++)
{
si--;
bx++;
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef--) * vbuf[si];
si = (si + 64) & 511;
sum += (*coef--) * vbuf[bx];
bx = (bx + 64) & 511;
}
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm = tmp;
pcm += 2;
}
}
/*------------------------------------------------------------*/
/*------------------- 16 pt window ------------------------------*/
void window16(float *vbuf, int vb_ptr, short *pcm)
{
int i, j;
unsigned char si, bx;
const float *coef;
float sum;
long tmp;
si = vb_ptr + 8;
bx = si + 16;
coef = wincoef;
/*-- first 8 --*/
for (i = 0; i < 8; i++)
{
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef++) * vbuf[si];
si += 32;
sum -= (*coef++) * vbuf[bx];
bx += 32;
}
si++;
bx--;
coef += 16;
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm++ = tmp;
}
/*-- special case --*/
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef++) * vbuf[bx];
bx += 32;
}
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm++ = tmp;
/*-- last 7 --*/
coef = wincoef + 255; /* back pass through coefs */
for (i = 0; i < 7; i++)
{
coef -= 16;
si--;
bx++;
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef--) * vbuf[si];
si += 32;
sum += (*coef--) * vbuf[bx];
bx += 32;
}
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm++ = tmp;
}
}
/*--------------- 16 pt dual window (interleaved output) -----------------*/
void window16_dual(float *vbuf, int vb_ptr, short *pcm)
{
int i, j;
unsigned char si, bx;
const float *coef;
float sum;
long tmp;
si = vb_ptr + 8;
bx = si + 16;
coef = wincoef;
/*-- first 8 --*/
for (i = 0; i < 8; i++)
{
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef++) * vbuf[si];
si += 32;
sum -= (*coef++) * vbuf[bx];
bx += 32;
}
si++;
bx--;
coef += 16;
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm = tmp;
pcm += 2;
}
/*-- special case --*/
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef++) * vbuf[bx];
bx += 32;
}
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm = tmp;
pcm += 2;
/*-- last 7 --*/
coef = wincoef + 255; /* back pass through coefs */
for (i = 0; i < 7; i++)
{
coef -= 16;
si--;
bx++;
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef--) * vbuf[si];
si += 32;
sum += (*coef--) * vbuf[bx];
bx += 32;
}
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm = tmp;
pcm += 2;
}
}
/*------------------- 8 pt window ------------------------------*/
void window8(float *vbuf, int vb_ptr, short *pcm)
{
int i, j;
int si, bx;
const float *coef;
float sum;
long tmp;
si = vb_ptr + 4;
bx = (si + 8) & 127;
coef = wincoef;
/*-- first 4 --*/
for (i = 0; i < 4; i++)
{
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef++) * vbuf[si];
si = (si + 16) & 127;
sum -= (*coef++) * vbuf[bx];
bx = (bx + 16) & 127;
}
si++;
bx--;
coef += 48;
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm++ = tmp;
}
/*-- special case --*/
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef++) * vbuf[bx];
bx = (bx + 16) & 127;
}
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm++ = tmp;
/*-- last 3 --*/
coef = wincoef + 255; /* back pass through coefs */
for (i = 0; i < 3; i++)
{
coef -= 48;
si--;
bx++;
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef--) * vbuf[si];
si = (si + 16) & 127;
sum += (*coef--) * vbuf[bx];
bx = (bx + 16) & 127;
}
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm++ = tmp;
}
}
/*--------------- 8 pt dual window (interleaved output) -----------------*/
void window8_dual(float *vbuf, int vb_ptr, short *pcm)
{
int i, j;
int si, bx;
const float *coef;
float sum;
long tmp;
si = vb_ptr + 4;
bx = (si + 8) & 127;
coef = wincoef;
/*-- first 4 --*/
for (i = 0; i < 4; i++)
{
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef++) * vbuf[si];
si = (si + 16) & 127;
sum -= (*coef++) * vbuf[bx];
bx = (bx + 16) & 127;
}
si++;
bx--;
coef += 48;
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm = tmp;
pcm += 2;
}
/*-- special case --*/
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef++) * vbuf[bx];
bx = (bx + 16) & 127;
}
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm = tmp;
pcm += 2;
/*-- last 3 --*/
coef = wincoef + 255; /* back pass through coefs */
for (i = 0; i < 3; i++)
{
coef -= 48;
si--;
bx++;
sum = 0.0F;
for (j = 0; j < 8; j++)
{
sum += (*coef--) * vbuf[si];
si = (si + 16) & 127;
sum += (*coef--) * vbuf[bx];
bx = (bx + 16) & 127;
}
tmp = (long) sum;
if (tmp > 32767)
tmp = 32767;
else if (tmp < -32768)
tmp = -32768;
*pcm = tmp;
pcm += 2;
}
}
/*------------------------------------------------------------*/
#endif // #ifdef COMPILE_ME