split client and server 5

client/src/client/audio/jorbis/Mdct.java

@@ -0,0 +1,250 @@
+/* -*-mode:java; c-basic-offset:2; indent-tabs-mode:nil -*- */
+/* JOrbis
+ * Copyright (C) 2000 ymnk, JCraft,Inc.
+ *  
+ * Written by: 2000 ymnk<ymnk@jcraft.com>
+ *   
+ * Many thanks to 
+ *   Monty <monty@xiph.org> and 
+ *   The XIPHOPHORUS Company http://www.xiph.org/ .
+ * JOrbis has been based on their awesome works, Vorbis codec.
+ *   
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library 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 Library General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Library General Public
+ * License along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+package client.audio.jorbis;
+
+class Mdct{
+
+  int n;
+  int log2n;
+
+  float[] trig;
+  int[] bitrev;
+
+  float scale;
+
+  void init(int n){
+    bitrev=new int[n/4];
+    trig=new float[n+n/4];
+
+    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){
+  }
+
+  float[] _x=new float[1024];
+  float[] _w=new float[1024];
+
+  synchronized void backward(float[] in, float[] out){
+    if(_x.length<n/2){
+      _x=new float[n/2];
+    }
+    if(_w.length<n/2){
+      _w=new float[n/2];
+    }
+    float[] x=_x;
+    float[] w=_w;
+    int n2=n>>>1;
+    int n4=n>>>2;
+    int n8=n>>>3;
+
+    // rotate + step 1
+    {
+      int inO=1;
+      int xO=0;
+      int A=n2;
+
+      int i;
+      for(i=0; i<n8; i++){
+        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++){
+        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=mdct_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++){
+        float temp1=(xxx[xx]*trig[B+1]-xxx[xx+1]*trig[B]);
+        float temp2=-(xxx[xx]*trig[B]+xxx[xx+1]*trig[B+1]);
+
+        out[o1]=-temp1;
+        out[o2]=temp1;
+        out[o3]=temp2;
+        out[o4]=temp2;
+
+        o1++;
+        o2--;
+        o3++;
+        o4--;
+        xx+=2;
+        B+=2;
+      }
+    }
+  }
+
+  private float[] mdct_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++){
+            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)*.5f;
+        x[x2--]=(-wD+wBCO-wACE)*.5f;
+        x[x1++]=(wD+wBCO-wACE)*.5f;
+        x[x2--]=(wC-wACO-wBCE)*.5f;
+      }
+    }
+    return (x);
+  }
+}