kolibrios-fun/programs/media/ac97 mp3/trunk/mp3dec/l3msis.c
Sergey Semyonov (Serge) 1634ac97c2 ac97_mp3 source code
git-svn-id: svn://kolibrios.org@165 a494cfbc-eb01-0410-851d-a64ba20cac60
2006-10-06 06:20:41 +00:00

333 lines
7.5 KiB
C

#include "layer3.h"
#include <math.h>
//#include <windows.h>
extern IS_SF_INFO m_is_sf_info;
extern int m_ms_mode, m_is_mode;
extern int m_sfBandIndex[2][22];// [long/short][cb]
extern int m_nBand[2][22];
/* intensity stereo */
/* if ms mode quant pre-scales all values by 1.0/sqrt(2.0) ms_mode in table
compensates */
/* [ms_mode 0/1][sf][left/right] */
static float lr[2][8][2];
/* lr2[intensity_scale][ms_mode][sflen_offset+sf][left/right] */
static float lr2[2][2][64][2];
/*-------*msis_init_addr()
pi = 4.0*atan(1.0);
t = pi/12.0;
for(i=0;i<7;i++) {
s = sin(i*t);
c = cos(i*t);
// ms_mode = 0
lr[0][i][0] = (float)(s/(s+c));
lr[0][i][1] = (float)(c/(s+c));
// ms_mode = 1
lr[1][i][0] = (float)(sqrt(2.0)*(s/(s+c)));
lr[1][i][1] = (float)(sqrt(2.0)*(c/(s+c)));
}
//sf = 7
//ms_mode = 0
lr[0][i][0] = 1.0f;
lr[0][i][1] = 0.0f;
// ms_mode = 1, in is bands is routine does ms processing
lr[1][i][0] = 1.0f;
lr[1][i][1] = 1.0f;
------------*/
/*===============================================================*/
void msis_init1()
{
int i;
double s, c;
double pi;
double t;
pi = 4.0 * atan(1.0);
t = pi / 12.0;
for (i = 0; i < 7; i++)
{
s = sin(i * t);
c = cos(i * t);
/* ms_mode = 0 */
lr[0][i][0] = (float) (s / (s + c));
lr[0][i][1] = (float) (c / (s + c));
/* ms_mode = 1 */
lr[1][i][0] = (float) (sqrt(2.0) * (s / (s + c)));
lr[1][i][1] = (float) (sqrt(2.0) * (c / (s + c)));
}
/* sf = 7 */
/* ms_mode = 0 */
lr[0][i][0] = 1.0f;
lr[0][i][1] = 0.0f;
/* ms_mode = 1, in is bands is routine does ms processing */
lr[1][i][0] = 1.0f;
lr[1][i][1] = 1.0f;
/*-------
for(i=0;i<21;i++) m_nBand[0][i] =
sfBandTable[sr_index].l[i+1] - sfBandTable[sr_index].l[i];
for(i=0;i<12;i++) m_nBand[1][i] =
sfBandTable[sr_index].s[i+1] - sfBandTable[sr_index].s[i];
-------------*/
}
/*===============================================================*/
void msis_init2()
{
int k, n;
double t;
int intensity_scale, ms_mode, sf, sflen;
float ms_factor[2];
ms_factor[0] = 1.0;
ms_factor[1] = (float) sqrt(2.0);
/* intensity stereo MPEG2 */
/* lr2[intensity_scale][ms_mode][sflen_offset+sf][left/right] */
for (intensity_scale = 0; intensity_scale < 2; intensity_scale++)
{
t = pow_test(2.0, -0.25 * (1 + intensity_scale));
for (ms_mode = 0; ms_mode < 2; ms_mode++)
{
n = 1;
k = 0;
for (sflen = 0; sflen < 6; sflen++)
{
for (sf = 0; sf < (n - 1); sf++, k++)
{
if (sf == 0)
{
lr2[intensity_scale][ms_mode][k][0] = ms_factor[ms_mode] * 1.0f;
lr2[intensity_scale][ms_mode][k][1] = ms_factor[ms_mode] * 1.0f;
}
else if ((sf & 1))
{
lr2[intensity_scale][ms_mode][k][0] =
(float) (ms_factor[ms_mode] * pow_test(t, (sf + 1) / 2));
lr2[intensity_scale][ms_mode][k][1] = ms_factor[ms_mode] * 1.0f;
}
else
{
lr2[intensity_scale][ms_mode][k][0] = ms_factor[ms_mode] * 1.0f;
lr2[intensity_scale][ms_mode][k][1] =
(float) (ms_factor[ms_mode] * pow_test(t, sf / 2));
}
}
/* illegal is_pos used to do ms processing */
if (ms_mode == 0)
{ /* ms_mode = 0 */
lr2[intensity_scale][ms_mode][k][0] = 1.0f;
lr2[intensity_scale][ms_mode][k][1] = 0.0f;
}
else
{
/* ms_mode = 1, in is bands is routine does ms processing */
lr2[intensity_scale][ms_mode][k][0] = 1.0f;
lr2[intensity_scale][ms_mode][k][1] = 1.0f;
}
k++;
n = n + n;
}
}
}
}
void msis_init()
{
msis_init1();
msis_init2();
}
/*===============================================================*/
void ms_process(float x[][1152], int n) /* sum-difference stereo */
{
int i;
float xl, xr;
/*-- note: sqrt(2) done scaling by dequant ---*/
for (i = 0; i < n; i++)
{
xl = x[0][i] + x[1][i];
xr = x[0][i] - x[1][i];
x[0][i] = xl;
x[1][i] = xr;
}
return;
}
void is_process1(float x[][1152], /* intensity stereo */
SCALE_FACTOR* sf,
CB_INFO cb_info[2], /* [ch] */
int nsamp)
{
int i, j, n, cb, w;
float fl, fr;
int m;
int isf;
float fls[3], frs[3];
int cb0;
cb0 = cb_info[1].cbmax; /* start at end of right */
i = m_sfBandIndex[cb_info[1].cbtype][cb0];
cb0++;
m = nsamp - i; /* process to len of left */
if (cb_info[1].cbtype)
goto short_blocks;
/*------------------------*/
/* long_blocks: */
for (cb = cb0; cb < 21; cb++)
{
isf = sf->l[cb];
n = m_nBand[0][cb];
fl = lr[m_ms_mode][isf][0];
fr = lr[m_ms_mode][isf][1];
for (j = 0; j < n; j++, i++)
{
if (--m < 0)
goto exit;
x[1][i] = fr * x[0][i];
x[0][i] = fl * x[0][i];
}
}
return;
/*------------------------*/
short_blocks:
for (cb = cb0; cb < 12; cb++)
{
for (w = 0; w < 3; w++)
{
isf = sf->s[w][cb];
fls[w] = lr[m_ms_mode][isf][0];
frs[w] = lr[m_ms_mode][isf][1];
}
n = m_nBand[1][cb];
for (j = 0; j < n; j++)
{
m -= 3;
if (m < 0)
goto exit;
x[1][i] = frs[0] * x[0][i];
x[0][i] = fls[0] * x[0][i];
x[1][1 + i] = frs[1] * x[0][1 + i];
x[0][1 + i] = fls[1] * x[0][1 + i];
x[1][2 + i] = frs[2] * x[0][2 + i];
x[0][2 + i] = fls[2] * x[0][2 + i];
i += 3;
}
}
exit:
return;
}
typedef float ARRAY2[2];
void is_process2(float x[][1152], /* intensity stereo */
SCALE_FACTOR* sf,
CB_INFO cb_info[2], /* [ch] */
int nsamp)
{
int i, j, k, n, cb, w;
float fl, fr;
int m;
int isf;
int il[21];
int tmp;
int r;
ARRAY2 *lr;
int cb0, cb1;
lr = lr2[m_is_sf_info.intensity_scale][m_ms_mode];
if (cb_info[1].cbtype)
goto short_blocks;
/*------------------------*/
/* long_blocks: */
cb0 = cb_info[1].cbmax; /* start at end of right */
i = m_sfBandIndex[0][cb0];
m = nsamp - i; /* process to len of left */
/* gen sf info */
for (k = r = 0; r < 3; r++)
{
tmp = (1 << m_is_sf_info.slen[r]) - 1;
for (j = 0; j < m_is_sf_info.nr[r]; j++, k++)
il[k] = tmp;
}
for (cb = cb0 + 1; cb < 21; cb++)
{
isf = il[cb] + sf->l[cb];
// X-MaD 27-02-02
if (isf < 0) { isf = 0; }
fl = 0;
fr = 0;
//try
//{
fl = lr[isf][0];
fr = lr[isf][1];
n = m_nBand[0][cb];
//}
//catch(...)
//{
// isf = 0;
//}
// X-MaD 27-02-02
for (j = 0; j < n; j++, i++)
{
if (--m < 0)
{
goto exit;
}
x[1][i] = fr * x[0][i];
x[0][i] = fl * x[0][i];
}
}
return;
/*------------------------*/
short_blocks:
for (k = r = 0; r < 3; r++)
{
tmp = (1 << m_is_sf_info.slen[r]) - 1;
for (j = 0; j < m_is_sf_info.nr[r]; j++, k++)
il[k] = tmp;
}
for (w = 0; w < 3; w++)
{
cb0 = cb_info[1].cbmax_s[w]; /* start at end of right */
i = m_sfBandIndex[1][cb0] + w;
cb1 = cb_info[0].cbmax_s[w]; /* process to end of left */
for (cb = cb0 + 1; cb <= cb1; cb++)
{
isf = il[cb] + sf->s[w][cb];
fl = lr[isf][0];
fr = lr[isf][1];
n = m_nBand[1][cb];
for (j = 0; j < n; j++)
{
x[1][i] = fr * x[0][i];
x[0][i] = fl * x[0][i];
i += 3;
}
}
}
exit:
return;
}