gsmdecoder.java

java处理声音文件

//    $Id: GSMDecoder.java,v 1.1 2000/08/10 17:47:08 pfisterer Exp $	

//    This file is part of the GSM 6.10 audio decoder library for Java
//    Copyright (C) 1998 Steven Pickles ([e-mail])

//    This library 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 library 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 library; if not, write to the Free
//    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.



//  This software is a port of the GSM Library provided by
//  Jutta Degener ([e-mail]) and 
//  Carsten Bormann ([e-mail]), 
//  Technische Universitaet Berlin

package	org.tritonus.lowlevel.gsm;



public final class GSMDecoder
{
	private static final byte	GSM_MAGIC = 0x0d;

	private static final int[]	FAC = { 18431, 20479, 22527, 24575, 
						26623, 28671, 30719, 32767 };

	private static final int[]	QLB = { 3277, 11469, 21299, 32767 };

	// TODO: can be replaced by Short.MIN_VALUE and Short.MAX_VALUE ?
	private static final int	MIN_WORD = -32767 - 1;
	private static final int	MAX_WORD = 32767;


	private int	dp0[] = new int[280];

	private int	u[] = new int[8];
	private int	LARpp[][] = new int[2][8];
	private int	j;

	private int	nrp;
	private int	v[] = new int[9];
	private int	msr;



	public void GSM()
	{
		nrp = 40;
	}



	public final int[] decode(byte c[])
		throws InvalidGSMFrameException
	{
		if (c.length != 33)
		{
			throw new InvalidGSMFrameException();
		}

		int i=0;
    
		if (((c[i]>>4) & 0xf) != GSM_MAGIC)
		{
			throw new InvalidGSMFrameException();
		}
 
		int	LARc[] = new int[8];
		int	Nc[] = new int[4];
		int	Mc[] = new int[4];
		int	bc[] = new int[4];
		int	xmaxc[] = new int[4];
		int	xmc[] = new int[13 * 4];

		LARc[0]  = ((c[i++] & 0xF) << 2);           /* 1 */
		LARc[0] |= ((c[i] >> 6) & 0x3);
		LARc[1]  = (c[i++] & 0x3F);
		LARc[2]  = ((c[i] >> 3) & 0x1F);
		LARc[3]  = ((c[i++] & 0x7) << 2);
		LARc[3] |= ((c[i] >> 6) & 0x3);
		LARc[4]  = ((c[i] >> 2) & 0xF);
		LARc[5]  = ((c[i++] & 0x3) << 2);
		LARc[5] |= ((c[i] >> 6) & 0x3);
		LARc[6]  = ((c[i] >> 3) & 0x7);
		LARc[7]  = (c[i++] & 0x7);
		Nc[0]  = ((c[i] >> 1) & 0x7F);
		bc[0]  = ((c[i++] & 0x1) << 1);
		bc[0] |= ((c[i] >> 7) & 0x1);
		Mc[0]  = ((c[i] >> 5) & 0x3);
		xmaxc[0]  = ((c[i++] & 0x1F) << 1);
		xmaxc[0] |= ((c[i] >> 7) & 0x1);
		xmc[0]  = ((c[i] >> 4) & 0x7);
		xmc[1]  = ((c[i] >> 1) & 0x7);
		xmc[2]  = ((c[i++] & 0x1) << 2);
		xmc[2] |= ((c[i] >> 6) & 0x3);
		xmc[3]  = ((c[i] >> 3) & 0x7);
		xmc[4]  = (c[i++] & 0x7);
		xmc[5]  = ((c[i] >> 5) & 0x7);
		xmc[6]  = ((c[i] >> 2) & 0x7);
		xmc[7]  = ((c[i++] & 0x3) << 1);            /* 10 */
		xmc[7] |= ((c[i] >> 7) & 0x1);
		xmc[8]  = ((c[i] >> 4) & 0x7);
		xmc[9]  = ((c[i] >> 1) & 0x7);
		xmc[10]  = ((c[i++] & 0x1) << 2);
		xmc[10] |= ((c[i] >> 6) & 0x3);
		xmc[11]  = ((c[i] >> 3) & 0x7);
		xmc[12]  = (c[i++] & 0x7);
		Nc[1]  = ((c[i] >> 1) & 0x7F);
		bc[1]  = ((c[i++] & 0x1) << 1);
		bc[1] |= ((c[i] >> 7) & 0x1);
		Mc[1]  = ((c[i] >> 5) & 0x3);
		xmaxc[1]  = ((c[i++] & 0x1F) << 1);
		xmaxc[1] |= ((c[i] >> 7) & 0x1);
		xmc[13]  = ((c[i] >> 4) & 0x7);
		xmc[14]  = ((c[i] >> 1) & 0x7);
		xmc[15]  = ((c[i++] & 0x1) << 2);
		xmc[15] |= ((c[i] >> 6) & 0x3);
		xmc[16]  = ((c[i] >> 3) & 0x7);
		xmc[17]  = (c[i++] & 0x7);
		xmc[18]  = ((c[i] >> 5) & 0x7);
		xmc[19]  = ((c[i] >> 2) & 0x7);
		xmc[20]  = ((c[i++] & 0x3) << 1);
		xmc[20] |= ((c[i] >> 7) & 0x1);
		xmc[21]  = ((c[i] >> 4) & 0x7);
		xmc[22]  = ((c[i] >> 1) & 0x7);
		xmc[23]  = ((c[i++] & 0x1) << 2);
		xmc[23] |= ((c[i] >> 6) & 0x3);
		xmc[24]  = ((c[i] >> 3) & 0x7);
		xmc[25]  = (c[i++] & 0x7);
		Nc[2]  = ((c[i] >> 1) & 0x7F);
		bc[2]  = ((c[i++] & 0x1) << 1);             /* 20 */
		bc[2] |= ((c[i] >> 7) & 0x1);
		Mc[2]  = ((c[i] >> 5) & 0x3);
		xmaxc[2]  = ((c[i++] & 0x1F) << 1);
		xmaxc[2] |= ((c[i] >> 7) & 0x1);
		xmc[26]  = ((c[i] >> 4) & 0x7);
		xmc[27]  = ((c[i] >> 1) & 0x7);
		xmc[28]  = ((c[i++] & 0x1) << 2);
		xmc[28] |= ((c[i] >> 6) & 0x3);
		xmc[29]  = ((c[i] >> 3) & 0x7);
		xmc[30]  = (c[i++] & 0x7);
		xmc[31]  = ((c[i] >> 5) & 0x7);
		xmc[32]  = ((c[i] >> 2) & 0x7);
		xmc[33]  = ((c[i++] & 0x3) << 1);
		xmc[33] |= ((c[i] >> 7) & 0x1);
		xmc[34]  = ((c[i] >> 4) & 0x7);
		xmc[35]  = ((c[i] >> 1) & 0x7);
		xmc[36]  = ((c[i++] & 0x1) << 2);
		xmc[36] |= ((c[i] >> 6) & 0x3);
		xmc[37]  = ((c[i] >> 3) & 0x7);
		xmc[38]  = (c[i++] & 0x7);
		Nc[3]  = ((c[i] >> 1) & 0x7F);
		bc[3]  = ((c[i++] & 0x1) << 1);
		bc[3] |= ((c[i] >> 7) & 0x1);
		Mc[3]  = ((c[i] >> 5) & 0x3);
		xmaxc[3]  = ((c[i++] & 0x1F) << 1);
		xmaxc[3] |= ((c[i] >> 7) & 0x1);
		xmc[39]  = ((c[i] >> 4) & 0x7);
		xmc[40]  = ((c[i] >> 1) & 0x7);
		xmc[41]  = ((c[i++] & 0x1) << 2);
		xmc[41] |= ((c[i] >> 6) & 0x3);
		xmc[42]  = ((c[i] >> 3) & 0x7);
		xmc[43]  = (c[i++] & 0x7);                  /* 30  */
		xmc[44]  = ((c[i] >> 5) & 0x7);
		xmc[45]  = ((c[i] >> 2) & 0x7);
		xmc[46]  = ((c[i++] & 0x3) << 1);
		xmc[46] |= ((c[i] >> 7) & 0x1);
		xmc[47]  = ((c[i] >> 4) & 0x7);
		xmc[48]  = ((c[i] >> 1) & 0x7);
		xmc[49]  = ((c[i++] & 0x1) << 2);
		xmc[49] |= ((c[i] >> 6) & 0x3);
		xmc[50]  = ((c[i] >> 3) & 0x7);
		xmc[51]  = (c[i] & 0x7);                    /* 33 */
   
		return decoder(LARc, Nc, bc, Mc, xmaxc, xmc);
	}



	public final static void print(String name, int data[])
	{
		System.out.print("["+name+":");
		for(int i=0;i<data.length;i++)
		{
			System.out.print(""+data[i]);
			if (i<data.length-1)
			{
				System.out.print(",");
			}
			else
			{
				System.out.println("]");
			}
		}
	}



	public final static void print(String name, int data)
	{
		System.out.println("["+name+":"+data+"]");
	}



	private final int[] decoder(int LARcr[], 
				    int Ncr[], 
				    int bcr[], 
				    int Mcr[], 
				    int xmaxcr[], 
				    int xMcr[])
	{
		int	j, k;
		int	erp[] = new int[40];
		int	wt[] = new int[160];
		// drp is just dp0+120

		//print("LARcr",LARcr);
		//print("Ncr",Ncr);
		//print("bcr",bcr);
		//print("Mcr",Mcr);
		//print("xmaxcr",xmaxcr);
		//print("xMcr",xMcr);

		for (j=0;j<4;j++)
		{
			// find out what is done with xMcr
			RPEDecoding(xmaxcr[j],Mcr[j],xMcr,j*13,erp);

			//print("erp",erp);

			longTermSynthesisFiltering(Ncr[j],bcr[j],erp,dp0);
      
			for (k=0;k<40;k++)
			{
				wt[j*40+k] = dp0[120+k];
			}

		}

		//print("LARcr",LARcr);
    
		//print("wt",wt);
    
		int s[] = shortTermSynthesisFilter(LARcr,wt);

		//print("s",s);
    
		postprocessing(s);

		return s;
    
	}



	private final void RPEDecoding(int xmaxcr,
				       int Mcr,
				       int xMcr[],
				       int xMcrOffset,
				       int erp[])
	{
		int expAndMant[];
		int xMp[] = new int[13];

		expAndMant = xmaxcToExpAndMant(xmaxcr);

		//System.out.println("[e&m:"+expAndMant[0]+","+expAndMant[1]+"]");

		APCMInverseQuantization(xMcr,xMcrOffset,expAndMant[0],expAndMant[1],xMp);

		//print("xMp",xMp);

		RPE_grid_positioning( Mcr, xMp, erp);

	}



	private final int[] xmaxcToExpAndMant(int xmaxc)
	{
		int exp, mant;

		exp = 0;
		if (xmaxc>15)
		{
			exp = ((xmaxc>>3)-1);
		}
		mant=(xmaxc-(exp<<3));

		if (mant==0)
		{
			exp = -4;
			mant = 7;
		}
		else
		{
			while (mant <= 7)
			{
				mant = (mant << 1 | 1);
				exp--;
			}
			mant -= 8;
		}

		//assert(exp>=-4 && exp <= 6);
		//assert(mant>=0 && mant<=7);

		int result[] = new int[2];
		result[0] = exp;
		result[1] = mant;

		return result;

	}


	//private void assert(boolean test) {
	//  if (!test) {
	//    System.out.println("assertion error");
	//  }
	//}



	private final void APCMInverseQuantization(int xMc[], 
						   int xMcOffset,
						   int exp,
						   int mant,
						   int xMp[])
	{
		int i,p;
		int temp, temp1, temp2, temp3;
		int ltmp;

		//assert(mant >0 && mant <= 7 );

		temp1 = FAC[mant];
		temp2 = sub(6,exp);
		temp3 = asl(1,sub(temp2,1));

		//System.out.println("temp1="+temp1);
		//System.out.println("temp2="+temp2);
		//System.out.println("temp3="+temp3);

		p = 0;

		for (i=13;i-->0;)
		{
			//assert(xMc[xMcOffset] <= 7 && xMc[xMcOffset] >= 0);

			temp = ((xMc[xMcOffset++] << 1) - 7);

			//System.out.println("s1:temp="+temp);      

			//assert(temp<=7 && temp >= -7);

			temp = (temp<<12);//&0xffff;

			//System.out.println("s2:temp="+temp);      

			temp = mult_r(temp1, temp);

			//System.out.println("s3:temp="+temp);      

			temp = add(temp, temp3);

			//System.out.println("s4:temp="+temp);      

			xMp[p++] = asr(temp, temp2);
		}
	}



	private final static int saturate(int x)