/*
* $ProjectName$
* $ProjectRevision$
* -----------------------------------------------------------
* $Id: MdctFloat.java,v 1.3 2003/04/10 19:49:04 jarnbjo Exp $
* -----------------------------------------------------------
*
* $Author: jarnbjo $
*
* Description:
*
* Copyright 2002-2003 Tor-Einar Jarnbjo
* -----------------------------------------------------------
*
* Change History
* -----------------------------------------------------------
* $Log: MdctFloat.java,v $
* Revision 1.3 2003/04/10 19:49:04 jarnbjo
* no message
*
* Revision 1.2 2003/03/16 01:11:12 jarnbjo
* no message
*
*
*/
package sound.jarnbjo.vorbis;
public class MdctFloat {
static private final float cPI3_8=0.38268343236508977175f;
static private final float cPI2_8=0.70710678118654752441f;
static private final float cPI1_8=0.92387953251128675613f;
private int n;
private int log2n;
private float[] trig;
private int[] bitrev;
private float[] equalizer;
private float scale;
private int itmp1, itmp2, itmp3, itmp4, itmp5, itmp6, itmp7, itmp8, itmp9;
private float dtmp1, dtmp2, dtmp3, dtmp4, dtmp5, dtmp6, dtmp7, dtmp8, dtmp9;
protected MdctFloat(int n) {
bitrev=new int[n/4];
trig=new float[n+n/4];
int n2=n>>>1;
log2n=(int)Math.rint(Math.log(n)/Math.log(2));
this.n=n;
int AE=0;
int AO=1;
int BE=AE+n/2;
int BO=BE+1;
int CE=BE+n/2;
int CO=CE+1;
// trig lookups...
for(int i=0;i<n/4;i++){
trig[AE+i*2]=(float)Math.cos((Math.PI/n)*(4*i));
trig[AO+i*2]=(float)-Math.sin((Math.PI/n)*(4*i));
trig[BE+i*2]=(float)Math.cos((Math.PI/(2*n))*(2*i+1));
trig[BO+i*2]=(float)Math.sin((Math.PI/(2*n))*(2*i+1));
}
for(int i=0;i<n/8;i++){
trig[CE+i*2]=(float)Math.cos((Math.PI/n)*(4*i+2));
trig[CO+i*2]=(float)-Math.sin((Math.PI/n)*(4*i+2));
}
{
int mask=(1<<(log2n-1))-1;
int msb=1<<(log2n-2);
for(int i=0;i<n/8;i++){
int acc=0;
for(int j=0;msb>>>j!=0;j++)
if(((msb>>>j)&i)!=0)acc|=1<<j;
bitrev[i*2]=((~acc)&mask);
// bitrev[i*2]=((~acc)&mask)-1;
bitrev[i*2+1]=acc;
}
}
scale=4.f/n;
}
//void clear(){
//}
//void forward(float[] in, float[] out){
//}
private float[] _x=new float[1024];
private float[] _w=new float[1024];
protected void setEqualizer(float[] equalizer) {
this.equalizer=equalizer;
}
protected float[] getEqualizer() {
return equalizer;
}
protected synchronized void imdct(final float[] frq, final float[] window, final int[] pcm) {//, float[] out){
float[] in=frq;//, out=buf;
if(_x.length<n/2){_x=new float[n/2];}
if(_w.length<n/2){_w=new float[n/2];}
final float[] x=_x;
final float[] w=_w;
int n2=n>>1;
int n4=n>>2;
int n8=n>>3;
if(equalizer!=null) {
for(int i=0; i<n; i++) {
frq[i]*=equalizer[i];
}
}
// rotate + step 1
{
int inO=-1;
int xO=0;
int A=n2;
int i;
for(i=0;i<n8;i++) {
dtmp1=in[inO+=2];
dtmp2=in[inO+=2];
dtmp3=trig[--A];
dtmp4=trig[--A];
x[xO++]=-dtmp2*dtmp3 - dtmp1*dtmp4;
x[xO++]= dtmp1*dtmp3 - dtmp2*dtmp4;
//A-=2;
//x[xO++]=-in[inO+2]*trig[A+1] - in[inO]*trig[A];
//x[xO++]= in[inO]*trig[A+1] - in[inO+2]*trig[A];
//inO+=4;
}
inO=n2;//-4;
for(i=0;i<n8;i++) {
dtmp1=in[inO-=2];
dtmp2=in[inO-=2];
dtmp3=trig[--A];
dtmp4=trig[--A];
x[xO++]=dtmp2*dtmp3 + dtmp1*dtmp4;
x[xO++]=dtmp2*dtmp4 - dtmp1*dtmp3;
//A-=2;
//x[xO++]=in[inO]*trig[A+1] + in[inO+2]*trig[A];
//x[xO++]=in[inO]*trig[A] - in[inO+2]*trig[A+1];
//inO-=4;
}
}
float[] xxx=kernel(x,w,n,n2,n4,n8);
int xx=0;
// step 8
{
int B=n2;
int o1=n4,o2=o1-1;
int o3=n4+n2,o4=o3-1;
for(int i=0;i<n4;i++){
dtmp1=xxx[xx++];
dtmp2=xxx[xx++];
dtmp3=trig[B++];
dtmp4=trig[B++];
float temp1= (dtmp1* dtmp4 - dtmp2 * dtmp3);
float temp2=-(dtmp1 * dtmp3 + dtmp2 * dtmp4);
/*
float temp1= (xxx[xx] * trig[B+1] - xxx[xx+1] * trig[B]);//*32767.0f;
float temp2=-(xxx[xx] * trig[B] + xxx[xx+1] * trig[B+1]);//*32767.0f;
*/
//if(temp1>32767.0f) temp1=32767.0f;
//if(temp1<-32768.0f) temp1=-32768.0f;
//if(temp2>32767.0f) temp2=32767.0f;
//if(temp2<-32768.0f) temp2=-32768.0f;
pcm[o1]=(int)(-temp1*window[o1]);
pcm[o2]=(int)( temp1*window[o2]);
pcm[o3]=(int)( temp2*window[o3]);
pcm[o4]=(int)( temp2*window[o4]);
o1++;
o2--;
o3++;
o4--;
//xx+=2;
//B+=2;
}
}
}
private float[] kernel(float[] x, float[] w,
int n, int n2, int n4, int n8){
// step 2
int xA=n4;
int xB=0;
int w2=n4;
int A=n2;
for(int i=0;i<n4;){
float x0=x[xA] - x[xB];
float x1;
w[w2+i]=x[xA++]+x[xB++];
x1=x[xA]-x[xB];
A-=4;
w[i++]= x0 * trig[A] + x1 * trig[A+1];
w[i]= x1 * trig[A] - x0 * trig[A+1];
w[w2+i]=x[xA++]+x[xB++];
i++;
}
// step 3
{
for(int i=0;i<log2n-3;i++){
int k0=n>>>(i+2);
int k1=1<<(i+3);
int wbase=n2-2;
A=0;
float[] temp;
for(int r=0;r<(k0>>>2);r++){
int w1=wbase;
w2=w1-(k0>>1);
float AEv= trig[A],wA;
float AOv= trig[A+1],wB;
wbase-=2;
k0++;
for(int s=0;s<(2<<i);s++){
dtmp1=w[w1];
dtmp2=w[w2];
wB=dtmp1-dtmp2;
x[w1]=dtmp1+dtmp2;
dtmp1=w[++w1];
dtmp2=w[++w2];
wA=dtmp1-dtmp2;
x[w1]=dtmp1+dtmp2;
x[w2] =wA*AEv - wB*AOv;
x[w2-1]=wB*AEv + wA*AOv;
/*
wB =w[w1] -w[w2];
x[w1] =w[w1] +w[w2];
wA =w[++w1] -w[++w2];
x[w1] =w[w1] +w[w2];
x[w2] =wA*AEv - wB*AOv;
x[w2-1]=wB*AEv + wA*AOv;
*/
w1-=k0;
w2-=k0;
}
k0--;
A+=k1;
}
temp=w;
w=x;
x=temp;
}
}
// step 4, 5, 6, 7
{
int C=n;
int bit=0;
int x1=0;
int x2=n2-1;
for(int i=0;i<n8;i++) {
int t1=bitrev[bit++];
int t2=bitrev[bit++];
float wA=w[t1]-w[t2+1];
float wB=w[t1-1]+w[t2];
float wC=w[t1]+w[t2+1];
float wD=w[t1-1]-w[t2];
float wACE=wA* trig[C];
float wBCE=wB* trig[C++];
float wACO=wA* trig[C];
float wBCO=wB* trig[C++];
x[x1++]=( wC+wACO+wBCE)*16383.0f;
x[x2--]=(-wD+wBCO-wACE)*16383.0f;
x[x1++]=( wD+wBCO-wACE)*16383.0f;
x[x2--]=( wC-wACO-wBCE)*16383.0f;
}
}
return x;
}
}