ref: 11af283c2493c1b03adcc5d668f4b1a415178883
dir: /transfo.c/
/*
* MDCT transform
*
* Copyright (c) 1999 M. Bakker
*
* 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, 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; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/**************************************************************************
Version Control Information Method: CVS
Identifiers:
$Revision: 1.19 $
$Date: 2000/10/06 14:47:27 $ (check in)
$Author: menno $
*************************************************************************/
#include <math.h>
#include <memory.h>
#include "transfo.h"
#include "shape_win.h"
#define NFLAT_LS 448 // (BLOCK_LEN_LONG - BLOCK_LEN_SHORT) / 2
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif
#ifndef M_PI_2
#define M_PI_2 1.57079632679489661923
#endif
int sizedouble;
double wpi256,wpr256;
double wpi2048,wpr2048;
/*******************************************************************************
Fast MDCT & IMDCT Code
*******************************************************************************/
void MDCT (double *data, int N)
{
double tempr, tempi, c, s, cold, cfreq, sfreq; /* temps for pre and post twiddle */
double freq = 2.0 * M_PI / N;
double fac,cosfreq8,sinfreq8;
int i, n;
int b = N >> 1;
int N4 = N >> 2;
int N2 = N >> 1;
int a = N - b;
int a2 = a >> 1;
int a4 = a >> 2;
int b4 = b >> 2;
int unscambled;
/* Choosing to allocate 2/N factor to Inverse Xform! */
fac = 2.; /* 2 from MDCT inverse to forward */
/* prepare for recurrence relation in pre-twiddle */
cfreq = cos (freq);
sfreq = sin (freq);
cosfreq8 = cos (freq * 0.125);
sinfreq8 = sin (freq * 0.125);
c = cosfreq8;
s = sinfreq8;
for (i = 0; i < N4; i++) {
/* calculate real and imaginary parts of g(n) or G(p) */
n = N / 2 - 1 - 2 * i;
if (i < b4)
tempr = data [a2 + n] + data [N + a2 - 1 - n]; /* use second form of e(n) for n = N / 2 - 1 - 2i */
else
tempr = data [a2 + n] - data [a2 - 1 - n]; /* use first form of e(n) for n = N / 2 - 1 - 2i */
n = 2 * i;
if (i < a4)
tempi = data [a2 + n] - data [a2 - 1 - n]; /* use first form of e(n) for n=2i */
else
tempi = data [a2 + n] + data [N + a2 - 1 - n]; /* use second form of e(n) for n=2i*/
/* calculate pre-twiddled FFT input */
FFTarray [i].re = tempr * c + tempi * s;
FFTarray [i].im = tempi * c - tempr * s;
/* use recurrence to prepare cosine and sine for next value of i */
cold = c;
c = c * cfreq - s * sfreq;
s = s * cfreq + cold * sfreq;
}
/* Perform in-place complex FFT of length N/4 */
switch (N) {
case 256:
pfftw_64(FFTarray);
break;
case 2048:
pfftw_512(FFTarray);
}
/* prepare for recurrence relations in post-twiddle */
c = cosfreq8;
s = sinfreq8;
/* post-twiddle FFT output and then get output data */
for (i = 0; i < N4; i++) {
/* get post-twiddled FFT output */
/* Note: fac allocates 4/N factor from IFFT to forward and inverse */
switch (N) {
case 256:
unscambled = unscambled64[i];
break;
case 2048:
unscambled = unscambled512[i];
}
tempr = fac * (FFTarray [unscambled].re * c + FFTarray [unscambled].im * s);
tempi = fac * (FFTarray [unscambled].im * c - FFTarray [unscambled].re * s);
/* fill in output values */
data [2 * i] = -tempr; /* first half even */
data [N2 - 1 - 2 * i] = tempi; /* first half odd */
data [N2 + 2 * i] = -tempi; /* second half even */
data [N - 1 - 2 * i] = tempr; /* second half odd */
/* use recurrence to prepare cosine and sine for next value of i */
cold = c;
c = c * cfreq - s * sfreq;
s = s * cfreq + cold * sfreq;
}
}
void IMDCT(double *data, int N)
{
double tempr, tempi, c, s, cold, cfreq, sfreq; /* temps for pre and post twiddle */
double freq = 2.0 * M_PI / N;
double fac, cosfreq8, sinfreq8;
int i;
int Nd2 = N >> 1;
int Nd4 = N >> 2;
int Nd8 = N >> 3;
int unscambled;
/* Choosing to allocate 2/N factor to Inverse Xform! */
fac = 2. / N; /* remaining 2/N from 4/N IFFT factor */
/* prepare for recurrence relation in pre-twiddle */
cfreq = cos (freq);
sfreq = sin (freq);
cosfreq8 = cos (freq * 0.125);
sinfreq8 = sin (freq * 0.125);
c = cosfreq8;
s = sinfreq8;
for (i = 0; i < Nd4; i++) {
/* calculate real and imaginary parts of g(n) or G(p) */
tempr = -data [2 * i];
tempi = data [Nd2 - 1 - 2 * i];
/* calculate pre-twiddled FFT input */
switch (N) {
case 256:
unscambled = unscambled64[i];
break;
case 2048:
unscambled = unscambled512[i];
}
FFTarray [unscambled].re = tempr * c - tempi * s;
FFTarray [unscambled].im = tempi * c + tempr * s;
/* use recurrence to prepare cosine and sine for next value of i */
cold = c;
c = c * cfreq - s * sfreq;
s = s * cfreq + cold * sfreq;
}
/* Perform in-place complex IFFT of length N/4 */
switch (N) {
case 256:
pfftwi_64(FFTarray);
break;
case 2048:pfftwi_512(FFTarray);
}
/* prepare for recurrence relations in post-twiddle */
c = cosfreq8;
s = sinfreq8;
/* post-twiddle FFT output and then get output data */
for (i = 0; i < Nd4; i++) {
/* get post-twiddled FFT output */
tempr = fac * (FFTarray[i].re * c - FFTarray[i].im * s);
tempi = fac * (FFTarray[i].im * c + FFTarray[i].re * s);
/* fill in output values */
data [Nd2 + Nd4 - 1 - 2 * i] = tempr;
if (i < Nd8)
data [Nd2 + Nd4 + 2 * i] = tempr;
else
data [2 * i - Nd4] = -tempr;
data [Nd4 + 2 * i] = tempi;
if (i < Nd8)
data [Nd4 - 1 - 2 * i] = -tempi;
else
data [Nd4 + N - 1 - 2*i] = tempi;
/* use recurrence to prepare cosine and sine for next value of i */
cold = c;
c = c * cfreq - s * sfreq;
s = s * cfreq + cold * sfreq;
}
}
void make_MDCT_windows(void)
{
int i;
for( i=0; i<BLOCK_LEN_LONG; i++ )
sin_window_long[i] = sin((M_PI/(2*BLOCK_LEN_LONG)) * (i + 0.5));
for( i=0; i<BLOCK_LEN_SHORT; i++ )
sin_window_short[i] = sin((M_PI/(2*BLOCK_LEN_SHORT)) * (i + 0.5));
sizedouble = sizeof (double);
}
/*******************************************************************************
T/F mapping
*******************************************************************************/
void buffer2freq(double p_in_data[],
double p_out_mdct[],
double p_overlap[],
enum WINDOW_TYPE block_type,
Window_shape wfun_select, /* current window shape */
Window_shape wfun_select_prev, /* previous window shape */
Mdct_in overlap_select
)
{
double transf_buf[ 2*BLOCK_LEN_LONG ];
double *p_o_buf, *first_window, *second_window;
int k,i;
static int firstTime=1;
/* create / shift old values */
/* We use p_overlap here as buffer holding the last frame time signal*/
if(overlap_select != MNON_OVERLAPPED){
if (firstTime){
firstTime=0;
memset(transf_buf,0,BLOCK_LEN_LONG*sizedouble);
}
else
memcpy(transf_buf,p_overlap,BLOCK_LEN_LONG*sizedouble);
memcpy(transf_buf+BLOCK_LEN_LONG,p_in_data,BLOCK_LEN_LONG*sizedouble);
memcpy(p_overlap,p_in_data,BLOCK_LEN_LONG*sizedouble);
}
else {
memcpy(transf_buf,p_in_data,2*BLOCK_LEN_LONG*sizedouble);
}
/* Window shape processing */
switch (wfun_select_prev){
case WS_SIN:
if ( (block_type == ONLY_LONG_WINDOW) || (block_type == LONG_SHORT_WINDOW))
first_window = sin_window_long;
else
first_window = sin_window_short;
break;
case WS_KBD:
if ( (block_type == ONLY_LONG_WINDOW) || (block_type == LONG_SHORT_WINDOW))
first_window = kbd_window_long;
else
first_window = kbd_window_short;
break;
}
switch (wfun_select){
case WS_SIN:
if ( (block_type == ONLY_LONG_WINDOW) || (block_type == SHORT_LONG_WINDOW))
second_window = sin_window_long;
else
second_window = sin_window_short;
break;
case WS_KBD:
if ( (block_type == ONLY_LONG_WINDOW) || (block_type == SHORT_LONG_WINDOW))
second_window = kbd_window_long;
else
second_window = kbd_window_short;
break;
}
/* Set ptr to transf-Buffer */
p_o_buf = transf_buf;
/* Separate action for each Block Type */
switch( block_type ) {
case ONLY_LONG_WINDOW :
for ( i = 0 ; i < BLOCK_LEN_LONG ; i++){
p_out_mdct[i] = p_o_buf[i] * first_window[i];
p_out_mdct[i+BLOCK_LEN_LONG] = p_o_buf[i+BLOCK_LEN_LONG] * second_window[BLOCK_LEN_LONG-i-1];
}
MDCT( p_out_mdct, 2*BLOCK_LEN_LONG );
break;
case LONG_SHORT_WINDOW :
for ( i = 0 ; i < BLOCK_LEN_LONG ; i++)
p_out_mdct[i] = p_o_buf[i] * first_window[i];
memcpy(p_out_mdct+BLOCK_LEN_LONG,p_o_buf+BLOCK_LEN_LONG,NFLAT_LS*sizedouble);
// for ( ; i < NFLAT_LS + BLOCK_LEN_LONG; i++){
// p_out_mdct[i] = 1.0;
// p_out_mdct[i+NFLAT_LS+BLOCK_LEN_SHORT] = 0.0;
// }
for ( i = 0 ; i < BLOCK_LEN_SHORT ; i++)
p_out_mdct[i+BLOCK_LEN_LONG+NFLAT_LS] = p_o_buf[i+BLOCK_LEN_LONG+NFLAT_LS] * second_window[BLOCK_LEN_SHORT-i-1];
memset(p_out_mdct+BLOCK_LEN_LONG+NFLAT_LS+BLOCK_LEN_SHORT,0,NFLAT_LS*sizedouble);
MDCT( p_out_mdct, 2*BLOCK_LEN_LONG );
break;
case SHORT_LONG_WINDOW :
memset(p_out_mdct,0,NFLAT_LS*sizedouble);
// for ( i = 0 ; i < NFLAT_LS ; i++){
// p_out_mdct[i] = 0.0;
// p_out_mdct[i+NFLAT_LS+BLOCK_LEN_SHORT] = 1.0;
// }
for ( i = 0 ; i < BLOCK_LEN_SHORT ; i++)
p_out_mdct[i+NFLAT_LS] = p_o_buf[i+NFLAT_LS] * first_window[i];
memcpy(p_out_mdct+NFLAT_LS+BLOCK_LEN_SHORT,p_o_buf+NFLAT_LS+BLOCK_LEN_SHORT,NFLAT_LS*sizedouble);
for ( i = 0 ; i < BLOCK_LEN_LONG ; i++)
p_out_mdct[i+BLOCK_LEN_LONG] = p_o_buf[i+BLOCK_LEN_LONG] * second_window[BLOCK_LEN_LONG-i-1];
MDCT( p_out_mdct, 2*BLOCK_LEN_LONG );
break;
case ONLY_SHORT_WINDOW :
if(overlap_select != MNON_OVERLAPPED){ /* YT 970615 for sonPP */
p_o_buf += NFLAT_LS;
}
for ( k=0; k < MAX_SHORT_WINDOWS; k++ ) {
for ( i = 0 ; i < BLOCK_LEN_SHORT ; i++ ){
p_out_mdct[i] = p_o_buf[i] * first_window[i];
p_out_mdct[i+BLOCK_LEN_SHORT] = p_o_buf[i+BLOCK_LEN_SHORT] * second_window[BLOCK_LEN_SHORT-i-1];
}
MDCT( p_out_mdct, 2*BLOCK_LEN_SHORT );
p_out_mdct += BLOCK_LEN_SHORT;
if(overlap_select != MNON_OVERLAPPED)
p_o_buf += BLOCK_LEN_SHORT;
else
p_o_buf += 2*BLOCK_LEN_SHORT;
first_window = second_window;
}
break;
}
}
void freq2buffer(double p_in_data[],
double p_out_data[],
double p_overlap[],
enum WINDOW_TYPE block_type,
Window_shape wfun_select, /* current window shape */
Window_shape wfun_select_prev, /* previous window shape */
Mdct_in overlap_select
)
{
double *o_buf, transf_buf[ 2*BLOCK_LEN_LONG ];
double overlap_buf[ 2*BLOCK_LEN_LONG ], *first_window, *second_window;
double *fp;
int k,i;
/* Window shape processing */
switch (wfun_select_prev){
case WS_SIN:
if ( (block_type == ONLY_LONG_WINDOW) || (block_type == LONG_SHORT_WINDOW))
first_window = sin_window_long;
else
first_window = sin_window_short;
break;
case WS_KBD:
if ( (block_type == ONLY_LONG_WINDOW) || (block_type == LONG_SHORT_WINDOW))
first_window = kbd_window_long;
else
first_window = kbd_window_short;
break;
}
switch (wfun_select){
case WS_SIN:
if ( (block_type == ONLY_LONG_WINDOW) || (block_type == SHORT_LONG_WINDOW))
second_window = sin_window_long;
else
second_window = sin_window_short;
break;
case WS_KBD:
if ( (block_type == ONLY_LONG_WINDOW) || (block_type == SHORT_LONG_WINDOW))
second_window = kbd_window_long;
else
second_window = kbd_window_short;
break;
}
/* Assemble overlap buffer */
memcpy(overlap_buf,p_overlap,BLOCK_LEN_LONG*sizedouble);
o_buf = overlap_buf;
/* Separate action for each Block Type */
switch( block_type ) {
case ONLY_LONG_WINDOW :
memcpy(transf_buf, p_in_data,BLOCK_LEN_LONG*sizedouble);
IMDCT( transf_buf, 2*BLOCK_LEN_LONG );
for ( i = 0 ; i < BLOCK_LEN_LONG ; i++)
transf_buf[i] *= first_window[i];
if (overlap_select != MNON_OVERLAPPED) {
for ( i = 0 ; i < BLOCK_LEN_LONG; i++ ){
o_buf[i] += transf_buf[i];
o_buf[i+BLOCK_LEN_LONG] = transf_buf[i+BLOCK_LEN_LONG] * second_window[BLOCK_LEN_LONG-i-1];
}
}
else { /* overlap_select == NON_OVERLAPPED */
for ( i = 0 ; i < BLOCK_LEN_LONG; i++ )
transf_buf[i+BLOCK_LEN_LONG] *= second_window[BLOCK_LEN_LONG-i-1];
}
break;
case LONG_SHORT_WINDOW :
memcpy(transf_buf, p_in_data,BLOCK_LEN_LONG*sizedouble);
IMDCT( transf_buf, 2*BLOCK_LEN_LONG );
for ( i = 0 ; i < BLOCK_LEN_LONG ; i++)
transf_buf[i] *= first_window[i];
if (overlap_select != MNON_OVERLAPPED) {
for ( i = 0 ; i < BLOCK_LEN_LONG; i++ )
o_buf[i] += transf_buf[i];
memcpy(o_buf+BLOCK_LEN_LONG,transf_buf+BLOCK_LEN_LONG,NFLAT_LS*sizedouble);
for ( i = 0 ; i < BLOCK_LEN_SHORT ; i++)
o_buf[i+BLOCK_LEN_LONG+NFLAT_LS] = transf_buf[i+BLOCK_LEN_LONG+NFLAT_LS] * second_window[BLOCK_LEN_SHORT-i-1];
memset(o_buf+BLOCK_LEN_LONG+NFLAT_LS+BLOCK_LEN_SHORT,0,NFLAT_LS*sizedouble);
}
else { /* overlap_select == NON_OVERLAPPED */
for ( i = 0 ; i < BLOCK_LEN_SHORT ; i++)
transf_buf[i+BLOCK_LEN_LONG+NFLAT_LS] *= second_window[BLOCK_LEN_SHORT-i-1];
memset(transf_buf+BLOCK_LEN_LONG+NFLAT_LS+BLOCK_LEN_SHORT,0,NFLAT_LS*sizedouble);
}
break;
case SHORT_LONG_WINDOW :
memcpy(transf_buf, p_in_data,BLOCK_LEN_LONG*sizedouble);
IMDCT( transf_buf, 2*BLOCK_LEN_LONG );
for ( i = 0 ; i < BLOCK_LEN_SHORT ; i++)
transf_buf[i+NFLAT_LS] *= first_window[i];
if (overlap_select != MNON_OVERLAPPED) {
for ( i = 0 ; i < BLOCK_LEN_SHORT; i++ )
o_buf[i+NFLAT_LS] += transf_buf[i+NFLAT_LS];
memcpy(o_buf+BLOCK_LEN_SHORT+NFLAT_LS,transf_buf+BLOCK_LEN_SHORT+NFLAT_LS,NFLAT_LS*sizedouble);
for ( i = 0 ; i < BLOCK_LEN_LONG ; i++)
o_buf[i+BLOCK_LEN_LONG] = transf_buf[i+BLOCK_LEN_LONG] * second_window[BLOCK_LEN_LONG-i-1];
}
else { /* overlap_select == NON_OVERLAPPED */
memset(transf_buf,0,NFLAT_LS*sizedouble);
for ( i = 0 ; i < BLOCK_LEN_LONG ; i++)
transf_buf[i+BLOCK_LEN_LONG] *= second_window[BLOCK_LEN_LONG-i-1];
}
break;
case ONLY_SHORT_WINDOW :
if (overlap_select != MNON_OVERLAPPED) {
fp = o_buf + NFLAT_LS;
}
else { /* overlap_select == NON_OVERLAPPED */
fp = transf_buf;
}
for ( k=0; k < MAX_SHORT_WINDOWS; k++ ) {
memcpy(transf_buf,p_in_data,BLOCK_LEN_SHORT*sizedouble);
IMDCT( transf_buf, 2*BLOCK_LEN_SHORT );
p_in_data += BLOCK_LEN_SHORT;
if (overlap_select != MNON_OVERLAPPED) {
for ( i = 0 ; i < BLOCK_LEN_SHORT ; i++){
transf_buf[i] *= first_window[i];
fp[i] += transf_buf[i];
fp[i+BLOCK_LEN_SHORT] = transf_buf[i+BLOCK_LEN_SHORT] * second_window[BLOCK_LEN_SHORT-i-1];
}
fp += BLOCK_LEN_SHORT;
}
else { /* overlap_select == NON_OVERLAPPED */
for ( i = 0 ; i < BLOCK_LEN_SHORT ; i++){
fp[i] *= first_window[i];
fp[i+BLOCK_LEN_SHORT] *= second_window[BLOCK_LEN_SHORT-i-1];
}
fp += 2*BLOCK_LEN_SHORT;
}
first_window = second_window;
}
memset(o_buf+BLOCK_LEN_LONG+NFLAT_LS+BLOCK_LEN_SHORT,0,NFLAT_LS*sizedouble);
break;
}
if (overlap_select != MNON_OVERLAPPED)
memcpy(p_out_data,o_buf,BLOCK_LEN_LONG*sizedouble);
else /* overlap_select == NON_OVERLAPPED */
memcpy(p_out_data,transf_buf,2*BLOCK_LEN_LONG*sizedouble);
/* save unused output data */
memcpy(p_overlap,o_buf+BLOCK_LEN_LONG,BLOCK_LEN_LONG*sizedouble);
}
/******************************************************************************/
void specFilter (double p_in[],
double p_out[],
int samp_rate,
int lowpass_freq,
int specLen
)
{
int lowpass,xlowpass;
/* calculate the last line which is not zero */
lowpass = (lowpass_freq * specLen) / (samp_rate>>1) + 1;
xlowpass = (lowpass < specLen) ? lowpass : specLen ;
if( p_out != p_in )
memcpy(p_out,p_in,specLen*sizedouble);
memset(p_out+xlowpass,0,(specLen-xlowpass)*sizedouble);
}
void initrft(void)
{
double theta,wtemp;
theta = -M_PI/128.0;
wpi256 = sin(theta);
wtemp = sin(0.5*theta);
wpr256 = -2.0*wtemp*wtemp;
theta = -M_PI/1024.0;
wpi2048 = sin(theta);
wtemp = sin(0.5*theta);
wpr2048 = -2.0*wtemp*wtemp;
}
void realft256(double *data)
{
int i,i1,i2,i3,i4;
double h1r,h1i,h2r,h2i,t1,t2,t3;
double wr,wi,wtemp;
pfftw_128(FFTarray);
for (i = 0; i < 128; i++){
data[(i<<1)] = FFTarray[unscambled128[i]].re;
data[(i<<1)+1]= FFTarray[unscambled128[i]].im;
}
wr=1.0+wpr256;
wi=wpi256;
for (i=1;i<64;i++) {
i4=1+(i3=257-(i2=1+(i1=i+i)));
h1r=0.5*(data[i1]+data[i3]);
h1i=0.5*(data[i2]-data[i4]);
h2r=0.5*(data[i2]+data[i4]);
h2i=-0.5*(data[i1]-data[i3]);
t1=wr*h2r;
t2=wi*h2i;
t3=wr*h2i+wi*h2r;
data[i1]=h1r+t1-t2;
data[i2]=h1i+t3;
data[i3]=h1r-t1+t2;
data[i4]=-h1i+t3;
wtemp=wr;
wr=wtemp*wpr256-wi*wpi256+wr;
wi=wi*wpr256+wtemp*wpi256+wi;
}
data[0] = data[0]+data[1];
data[1] = 0;
data[129] = -data[129]; // hack to emulate complex FFT
}
void realft2048(double *data)
{
int i,i1,i2,i3,i4;
double h1r,h1i,h2r,h2i,t1,t2,t3;
double wr,wi,wtemp;
pfftw_1024(FFTarray);
for (i = 0; i < 1024; i++){
data[(i<<1)] = FFTarray[unscambled1024[i]].re;
data[(i<<1)+1]= FFTarray[unscambled1024[i]].im;
}
wr=1.0+wpr2048;
wi=wpi2048;
for (i=1;i<512;i++) {
i4=1+(i3=2049-(i2=1+(i1=i+i)));
h1r=0.5*(data[i1]+data[i3]);
h1i=0.5*(data[i2]-data[i4]);
h2r=0.5*(data[i2]+data[i4]);
h2i=-0.5*(data[i1]-data[i3]);
t1=wr*h2r;
t2=wi*h2i;
t3=wr*h2i+wi*h2r;
data[i1]=h1r+t1-t2;
data[i2]=h1i+t3;
data[i3]=h1r-t1+t2;
data[i4]=-h1i+t3;
wtemp=wr;
wr=wtemp*wpr2048-wi*wpi2048+wr;
wi=wi*wpr2048+wtemp*wpi2048+wi;
}
data[0] = data[0]+data[1];
data[1] = 0;
data[1025] = -data[1025]; // hack to emulate complex FFT
}