gsmdecoder.java

java处理声音文件

	{
		return (x<MIN_WORD ? MIN_WORD : (x>MAX_WORD?MAX_WORD: x));
	}



	private final static int sub(int a, int b)
	{
		int diff = a - b;
		return saturate(diff);
	}



	private final static int add(int a, int b)
	{
		int sum = a + b;
		return saturate(sum);
	}



	private final static int asl(int a, int n)
	{
		if (n>= 16) return 0;
		if (n<= -16) return (a<0?-1:0);
		if (n<0) return asr(a,-n);
		return (a << n);
	}



	private final static int asr(int a, int n)
	{
		if (n>=16) return (a<0?-1:0);
		if (n<=-16) return 0;
		if (n<0) return (a<<-n);//&0xffff;
		return (a>>n);
	}



	private final static int mult_r(int a, int b)
	{
		if (b == MIN_WORD && a == MIN_WORD) 
			return MAX_WORD;
		else
		{
			int prod = a * b + 16384;
			//prod >>= 15;
			return saturate(prod>>15);//&0xffff;
			//return (prod & 0xffff);
		}
	}



	private final void longTermSynthesisFiltering(int Ncr,
						      int bcr,
						      int erp[],
						      int dp0[])
	{
		int ltmp;
		int k;
		int brp, drpp, Nr;

		Nr = Ncr < 40 || Ncr > 120 ? nrp : Ncr;
		nrp = Nr;

		brp = QLB[bcr];

		for (k=0;k<=39;k++) {
			drpp = mult_r(brp,dp0[120+(k-Nr)]);
			dp0[120+k] = add(erp[k],drpp);
		}

		for (k=0;k<=119;k++) dp0[k]=dp0[40+k];

	}



	private final int[] shortTermSynthesisFilter(int LARcr[],
						     int wt[])
	{


		//print("wt",wt);
    



		int LARpp_j[] = LARpp[j];
		int LARpp_j_1[] = LARpp[j^=1];

		int LARp[] = new int[8];

		int s[] = new int[160];

		decodingOfTheCodedLogAreaRatios(LARcr,LARpp_j);

		//print("LARpp_j",LARpp_j);
    
		Coefficients_0_12(LARpp_j_1,LARpp_j,LARp);
		LARp_to_rp(LARp);
		shortTermSynthesisFiltering(LARp,13,wt,s,0);

		Coefficients_13_26( LARpp_j_1, LARpp_j, LARp);
		LARp_to_rp( LARp );
		shortTermSynthesisFiltering( LARp, 14, wt, s, 13);

		Coefficients_27_39( LARpp_j_1, LARpp_j, LARp);
		LARp_to_rp( LARp );
		shortTermSynthesisFiltering( LARp, 13, wt, s, 27 );

		Coefficients_40_159( LARpp_j, LARp );
		LARp_to_rp( LARp );
		shortTermSynthesisFiltering( LARp, 120, wt, s, 40);

		return s;

	}



	public final static void decodingOfTheCodedLogAreaRatios(int LARc[],
								 int LARpp[])
	{
		int temp1;
		int ltmp;

		// STEP(      0,  -32,  13107 );

		temp1 = (add(LARc[0],-32)<<10);
		//temp1 = (sub(temp1, 0));
		temp1 = (mult_r(13107,temp1));
		LARpp[0] = (add(temp1, temp1));

		//         STEP(      0,  -32,  13107 );

		temp1 = (add(LARc[1],-32)<<10);
		//temp1 = (sub(temp1, 0));
		temp1 = (mult_r(13107,temp1));
		LARpp[1] = (add(temp1, temp1));
    
		//         STEP(   2048,  -16,  13107 );

		temp1 = (add(LARc[2],-16)<<10);
		temp1 = (sub(temp1, 4096));
		temp1 = (mult_r(13107,temp1));
		LARpp[2] = (add(temp1, temp1));

		//         STEP(  -2560,  -16,  13107 );
    
		temp1 = (add(LARc[3],(-16))<<10);
		temp1 = (sub(temp1, -5120));
		temp1 = (mult_r(13107,temp1));
		LARpp[3] = (add(temp1, temp1));

		//         STEP(     94,   -8,  19223 );

		temp1 = (add(LARc[4],-8)<<10);
		temp1 = (sub(temp1, 188));
		temp1 = (mult_r(19223,temp1));
		LARpp[4] = (add(temp1, temp1));

		//         STEP(  -1792,   -8,  17476 );

		temp1 = (add(LARc[5],(-8))<<10);
		temp1 = (sub(temp1, -3584));
		temp1 = (mult_r(17476,temp1));
		LARpp[5] = (add(temp1, temp1));

		//         STEP(   -341,   -4,  31454 );

		temp1 = (add(LARc[6],(-4))<<10);
		temp1 = (sub(temp1, -682));
		temp1 = (mult_r(31454,temp1));
		LARpp[6] = (add(temp1, temp1));

		//         STEP(  -1144,   -4,  29708 );
    
		temp1 = (add(LARc[7],-4)<<10);
		temp1 = (sub(temp1, -2288));
		temp1 = (mult_r(29708,temp1));
		LARpp[7] = (add(temp1, temp1));

	}



	private final static void Coefficients_0_12(int LARpp_j_1[],
						    int LARpp_j[],
						    int LARp[])
	{
		int i;
		int ltmp;
    
		for(i=0;i<8;i++)
		{
			LARp[i] = add((LARpp_j_1[i]>>2),(LARpp_j[i]>>2));
			LARp[i] = add(LARp[i],(LARpp_j_1[i]>>1));
		}
	}



	private final static void Coefficients_13_26(int LARpp_j_1[],
						     int LARpp_j[],
						     int LARp[])
	{
		int i;
		int ltmp;
    
		for(i=0;i<8;i++)
		{
			LARp[i] = add((LARpp_j_1[i]>>1),(LARpp_j[i]>>1));
		}
	}



	private final static void Coefficients_27_39(int LARpp_j_1[],
						     int LARpp_j[],
						     int LARp[])
	{
		int i;
		int ltmp;
    
		for(i=0;i<8;i++)
		{
			LARp[i] = add((LARpp_j_1[i]>>2),(LARpp_j[i]>>2));
			LARp[i] = add(LARp[i],(LARpp_j[i]>>1));
		}
	}


  
	private final static void Coefficients_40_159(int LARpp_j[],
						      int LARp[])
	{
		int i;
		int ltmp;
    
		for(i=0;i<8;i++)
		{
			LARp[i] = LARpp_j[i];
		}
	}



	private final static void LARp_to_rp(int LARp[])
	{

		int i;
		int temp;

		for(i=0;i<8;i++)
		{
			if(LARp[i]<0)
			{
				temp = ((LARp[i]==MIN_WORD)?MAX_WORD:-LARp[i]);
				LARp[i] = (- ((temp < 11059) ? temp << 1
					      : ((temp < 20070) ? temp + 11059
						 : add((temp>>2),26112))));
			}
			else
			{
				temp = LARp[i];
				LARp[i] = ((temp<11059)?temp<<1
					   : ((temp<20070)?temp+11059
					      :add((temp>>2),26112)));
			}
		}
	}



	//      shortTermSynthesisFiltering(LARp,13,wt,s,0);
	private final void shortTermSynthesisFiltering(int rrp[],
						       int k,
						       int wt[],
						       int sr[],
						       int off)
	{
		int i;
		int sri, tmp1, tmp2;
		int woff = off;
		int soff = off;

		while (k-->0)
		{
			sri = wt[woff++];
			for (i=8;i-->0;)
			{
				tmp1 = rrp[i];
				tmp2 = v[i];
				tmp2 = ((tmp1==MIN_WORD && tmp2 == MIN_WORD
					 ? MAX_WORD
					 : saturate((tmp1*tmp2 + 16384)>>15)));
				sri = sub(sri,tmp2);

				tmp1 = ((tmp1 == MIN_WORD && sri == MIN_WORD
					 ? MAX_WORD
					 : saturate( (tmp1 *sri+16384) >>15)));
				v[i+1]=add(v[i],tmp1);
			}
			sr[soff++] = v[0] = sri;
		}
	}



	private final void postprocessing(int s[])
	{
		int k,soff=0;
		int tmp;
		for(k=160;k-->0;soff++)
		{
			tmp = mult_r(msr,(28180));
			msr = add(s[soff],tmp);
			//s[soff]=(add(msr,msr) & 0xfff8);
			s[soff]=saturate(add(msr,msr) & ~0x7);
		}
	}



	private final static void RPE_grid_positioning(int Mc,
						       int xMp[],
						       int ep[])
	{
		int i = 13;
    
		int epo = 0;
		int po = 0;

		switch(Mc)
		{
		case 3: ep[epo++] = 0;
		case 2: ep[epo++] = 0;
		case 1: ep[epo++] = 0;
		case 0: ep[epo++] = xMp[po++];
			i--;
		};
    
		do
		{
			ep[epo++] = 0;
			ep[epo++] = 0;
			ep[epo++] = xMp[po++];
		}
		while (--i>0);

		while (++Mc < 4)
		{
			ep[epo++] = 0;
		}
	}

}



/*** GSMDecoder.java ***/