/* * This source code is a product of Sun Microsystems, Inc. and is provided * for unrestricted use.  Users may copy or modify this source code without * charge. * * SUN SOURCE CODE IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING * THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE. * * Sun source code is provided with no support and without any obligation on * the part of Sun Microsystems, Inc. to assist in its use, correction, * modification or enhancement. * * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS SOFTWARE * OR ANY PART THEREOF. * * In no event will Sun Microsystems, Inc. be liable for any lost revenue * or profits or other special, indirect and consequential damages, even if * Sun has been advised of the possibility of such damages. * * Sun Microsystems, Inc. * 2550 Garcia Avenue * Mountain View, California  94043 *//* * g72x.c * * Common routines for G.721 and G.723 conversions. */#include "g72x.h"static short power2[15] = {1, 2, 4, 8, 0x10, 0x20, 0x40, 0x80,			0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000};/* * quan() * * quantizes the input val against the table of size short integers. * It returns i if table[i - 1] <= val < table[i]. * * Using linear search for simple coding. */static intquan(	int		val,	short		*table,	int		size){	int		i;	for (i = 0; i < size; i++)		if (val < *table++)			break;	return (i);}/* * fmult() * * returns the integer product of the 14-bit integer "an" and * "floating point" representation (4-bit exponent, 6-bit mantessa) "srn". */static intfmult(	int		an,	int		srn){	short		anmag, anexp, anmant;	short		wanexp, wanmag, wanmant;	short		retval;	anmag = (an > 0) ? an : ((-an) & 0x1FFF);	anexp = quan(anmag, power2, 15) - 6;	anmant = (anmag == 0) ? 32 :	    (anexp >= 0) ? anmag >> anexp : anmag << -anexp;	wanexp = anexp + ((srn >> 6) & 0xF) - 13;	wanmant = (anmant * (srn & 077) + 0x30) >> 4;	retval = (wanexp >= 0) ? ((wanmant << wanexp) & 0x7FFF) :	    (wanmant >> -wanexp);	return (((an ^ srn) < 0) ? -retval : retval);}/* * g72x_init_state() * * This routine initializes and/or resets the g72x_state structure * pointed to by 'state_ptr'. * All the initial state values are specified in the CCITT G.721 document. */voidg72x_init_state(	struct g72x_state *state_ptr){	int		cnta;	state_ptr->yl = 34816;	state_ptr->yu = 544;	state_ptr->dms = 0;	state_ptr->dml = 0;	state_ptr->ap = 0;	for (cnta = 0; cnta < 2; cnta++) {		state_ptr->a[cnta] = 0;		state_ptr->pk[cnta] = 0;		state_ptr->sr[cnta] = 32;	}	for (cnta = 0; cnta < 6; cnta++) {		state_ptr->b[cnta] = 0;		state_ptr->dq[cnta] = 32;	}	state_ptr->td = 0;}/* * predictor_zero() * * computes the estimated signal from 6-zero predictor. * */intpredictor_zero(	struct g72x_state *state_ptr){	int		i;	int		sezi;	sezi = fmult(state_ptr->b[0] >> 2, state_ptr->dq[0]);	for (i = 1; i < 6; i++)			/* ACCUM */		sezi += fmult(state_ptr->b[i] >> 2, state_ptr->dq[i]);	return (sezi);}/* * predictor_pole() * * computes the estimated signal from 2-pole predictor. * */intpredictor_pole(	struct g72x_state *state_ptr){	return (fmult(state_ptr->a[1] >> 2, state_ptr->sr[1]) +	    fmult(state_ptr->a[0] >> 2, state_ptr->sr[0]));}/* * step_size() * * computes the quantization step size of the adaptive quantizer. * */intstep_size(	struct g72x_state *state_ptr){	int		y;	int		dif;	int		al;	if (state_ptr->ap >= 256)		return (state_ptr->yu);	else {		y = state_ptr->yl >> 6;		dif = state_ptr->yu - y;		al = state_ptr->ap >> 2;		if (dif > 0)			y += (dif * al) >> 6;		else if (dif < 0)			y += (dif * al + 0x3F) >> 6;		return (y);	}}/* * quantize() * * Given a raw sample, 'd', of the difference signal and a * quantization step size scale factor, 'y', this routine returns the * ADPCM codeword to which that sample gets quantized.  The step * size scale factor division operation is done in the log base 2 domain * as a subtraction. */intquantize(	int		d,	/* Raw difference signal sample */	int		y,	/* Step size multiplier */	short		*table,	/* quantization table */	int		size)	/* table size of short integers */{	short		dqm;	/* Magnitude of 'd'   差值輸出信號絕對值*/	short		exp;	/* Integer part of base 2 log of 'd' 差值輸出信號2對數整數部分*/	short		mant;	/* Fractional part of base 2 log 差值輸出信號2對數小數部分*/	short		dl;	/* Log of magnitude of 'd' */	short		dln;	/* Step size scale factor normalized log */	int		i;	/*	 * LOG	 *	 * Compute base 2 log of 'd', and store in 'dl'.	 */	dqm = abs(d);	exp = quan(dqm >> 1, power2, 15);//計算以2為低的整數部分	mant = ((dqm << 7) >> exp) & 0x7F;	/* Fractional portion.計算以2為低小數部分 */	dl = (exp << 7) + mant;	/*	 * SUBTB	 *	 * "Divide" by step size multiplier.	 */	dln = dl - (y >> 2);	/*	 * QUAN	 *	 * Obtain codword i for 'd'.	 */	i = quan(dln, table, size);	if (d < 0)			/* take 1's complement of i */		return ((size << 1) + 1 - i);	else if (i == 0)		/* take 1's complement of 0 */		return ((size << 1) + 1); /* new in 1988 */	else		return (i);}/* * reconstruct() * * Returns reconstructed difference signal 'dq' obtained from * codeword 'i' and quantization step size scale factor 'y'. * Multiplication is performed in log base 2 domain as addition. */intreconstruct(	int		sign,	/* 0 for non-negative value */	int		dqln,	/* G.72x codeword */	int		y)	/* Step size multiplier */{	short		dql;	/* Log of 'dq' magnitude */	short		dex;	/* Integer part of log */	short		dqt;	short		dq;	/* Reconstructed difference signal sample */	dql = dqln + (y >> 2);	/* ADDA */	if (dql < 0) {		return ((sign) ? -0x8000 : 0);	} else {		/* ANTILOG */		dex = (dql >> 7) & 15;		dqt = 128 + (dql & 127);		dq = (dqt << 7) >> (14 - dex);		return ((sign) ? (dq - 0x8000) : dq);	}}/* * update() * * updates the state variables for each output code */voidupdate(	int		code_size,	/* distinguish 723_40 with others */	int		y,		/* quantizer step size 量化步長*/	int		wi,		/* scale factor multiplier 定標因子*/	int		fi,		/* for long/short term energies */	int		dq,		/* quantized prediction difference 自適應逆量化差*/	int		sr,		/* reconstructed signal 重建信號計算*/	int		dqsez,		/* difference from 2-pole predictor極點預測誤差 */	struct g72x_state *state_ptr)	/* coder state pointer */{	int		cnt;	short		mag, exp, mant;	/* Adaptive predictor, FLOAT A */	short		a2p;		/* LIMC */	short		a1ul;		/* UPA1 */	short		ua2, pks1;	/* UPA2 */	short		uga2a, fa1;	short		uga2b;	char		tr;		/* tone/transition detector */	short		ylint, thr2, dqthr;	short  		ylfrac, thr1;	short		pk0;	pk0 = (dqsez < 0) ? 1 : 0;	/* needed in updating predictor poles */	mag = dq & 0x7FFF;		/* prediction difference magnitude */	/* TRANS */	ylint = state_ptr->yl >> 15;	/* exponent part of yl */	ylfrac = (state_ptr->yl >> 10) & 0x1F;	/* fractional part of yl */	thr1 = (32 + ylfrac) << ylint;		/* threshold */	thr2 = (ylint > 9) ? 31 << 10 : thr1;	/* limit thr2 to 31 << 10 */	dqthr = (thr2 + (thr2 >> 1)) >> 1;	/* dqthr = 0.75 * thr2 */	if (state_ptr->td == 0)		/* signal supposed voice */		tr = 0;	else if (mag <= dqthr)		/* supposed data, but small mag */		tr = 0;			/* treated as voice */	else				/* signal is data (modem) */		tr = 1;	/*	 * Quantizer scale factor adaptation.	 */	/* FUNCTW & FILTD & DELAY */	/* update non-steady state step size multiplier */	state_ptr->yu = y + ((wi - y) >> 5);	/* LIMB */	if (state_ptr->yu < 544)	/* 544 <= yu <= 5120 */		state_ptr->yu = 544;	else if (state_ptr->yu > 5120)		state_ptr->yu = 5120;	/* FILTE & DELAY */	/* update steady state step size multiplier */	state_ptr->yl += state_ptr->yu + ((-state_ptr->yl) >> 6);	/*	 * Adaptive predictor coefficients.	 */	if (tr == 1) {			/* reset a's and b's for modem signal */		state_ptr->a[0] = 0;		state_ptr->a[1] = 0;		state_ptr->b[0] = 0;		state_ptr->b[1] = 0;		state_ptr->b[2] = 0;		state_ptr->b[3] = 0;		state_ptr->b[4] = 0;		state_ptr->b[5] = 0;	} else {			/* update a's and b's */		pks1 = pk0 ^ state_ptr->pk[0];		/* UPA2 */		/* update predictor pole a[1] */		a2p = state_ptr->a[1] - (state_ptr->a[1] >> 7);		if (dqsez != 0) {			fa1 = (pks1) ? state_ptr->a[0] : -state_ptr->a[0];			if (fa1 < -8191)	/* a2p = function of fa1 */				a2p -= 0x100;			else if (fa1 > 8191)				a2p += 0xFF;			else				a2p += fa1 >> 5;			if (pk0 ^ state_ptr->pk[1])				/* LIMC */				if (a2p <= -12160)					a2p = -12288;				else if (a2p >= 12416)					a2p = 12288;				else					a2p -= 0x80;			else if (a2p <= -12416)				a2p = -12288;			else if (a2p >= 12160)				a2p = 12288;			else				a2p += 0x80;		}		/* TRIGB & DELAY */		state_ptr->a[1] = a2p;		/* UPA1 */		/* update predictor pole a[0] */		state_ptr->a[0] -= state_ptr->a[0] >> 8;		if (dqsez != 0)			if (pks1 == 0)				state_ptr->a[0] += 192;			else				state_ptr->a[0] -= 192;		/* LIMD */		a1ul = 15360 - a2p;		if (state_ptr->a[0] < -a1ul)			state_ptr->a[0] = -a1ul;		else if (state_ptr->a[0] > a1ul)			state_ptr->a[0] = a1ul;		/* UPB : update predictor zeros b[6] */		for (cnt = 0; cnt < 6; cnt++) 
		{			if (code_size == 5)		/* for 40Kbps G.723 */				state_ptr->b[cnt] -= state_ptr->b[cnt] >> 9;			else			/* for G.721 and 24Kbps G.723 */				state_ptr->b[cnt] -= state_ptr->b[cnt] >> 8;			if (dq & 0x7FFF) 
			{			/* XOR */				if ((dq ^ state_ptr->dq[cnt]) >= 0)					state_ptr->b[cnt] += 128;				else					state_ptr->b[cnt] -= 128;			}		}	}	for (cnt = 5; cnt > 0; cnt--)		state_ptr->dq[cnt] = state_ptr->dq[cnt-1];	/* FLOAT A : convert dq[0] to 4-bit exp, 6-bit mantissa f.p. */	if (mag == 0) {		state_ptr->dq[0] = (dq >= 0) ? 0x20 : 0xFC20;	} else {		exp = quan(mag, power2, 15);		state_ptr->dq[0] = (dq >= 0) ?		    (exp << 6) + ((mag << 6) >> exp) :		    (exp << 6) + ((mag << 6) >> exp) - 0x400;	}	state_ptr->sr[1] = state_ptr->sr[0];	/* FLOAT B : convert sr to 4-bit exp., 6-bit mantissa f.p. */	if (sr == 0) {		state_ptr->sr[0] = 0x20;	} else if (sr > 0) {		exp = quan(sr, power2, 15);		state_ptr->sr[0] = (exp << 6) + ((sr << 6) >> exp);	} else if (sr > -32768) {		mag = -sr;		exp = quan(mag, power2, 15);		state_ptr->sr[0] =  (exp << 6) + ((mag << 6) >> exp) - 0x400;	} else		state_ptr->sr[0] = 0xFC20;	/* DELAY A */	state_ptr->pk[1] = state_ptr->pk[0];	state_ptr->pk[0] = pk0;	/* TONE */	if (tr == 1)		/* this sample has been treated as data */		state_ptr->td = 0;	/* next one will be treated as voice */	else if (a2p < -11776)	/* small sample-to-sample correlation */		state_ptr->td = 1;	/* signal may be data */	else				/* signal is voice */		state_ptr->td = 0;	/*	 * Adaptation speed control.	 */	state_ptr->dms += (fi - state_ptr->dms) >> 5;		/* FILTA */	state_ptr->dml += (((fi << 2) - state_ptr->dml) >> 7);	/* FILTB */	if (tr == 1)		state_ptr->ap = 256;	else if (y < 1536)					/* SUBTC */		state_ptr->ap += (0x200 - state_ptr->ap) >> 4;	else if (state_ptr->td == 1)		state_ptr->ap += (0x200 - state_ptr->ap) >> 4;	else if (abs((state_ptr->dms << 2) - state_ptr->dml) >=	    (state_ptr->dml >> 3))		state_ptr->ap += (0x200 - state_ptr->ap) >> 4;	else		state_ptr->ap += (-state_ptr->ap) >> 4;}/* * tandem_adjust(sr, se, y, i, sign) * * At the end of ADPCM decoding, it simulates an encoder which may be receiving * the output of this decoder as a tandem process. If the output of the * simulated encoder differs from the input to this decoder, the decoder output * is adjusted by one level of A-law or u-law codes. * * Input: *	sr	decoder output linear PCM sample, *	se	predictor estimate sample, *	y	quantizer step size, *	i	decoder input code, *	sign	sign bit of code i * * Return: *	adjusted A-law or u-law compressed sample. */inttandem_adjust_alaw(	int		sr,	/* decoder output linear PCM sample */	int		se,	/* predictor estimate sample */	int		y,	/* quantizer step size */	int		i,	/* decoder input code */	int		sign,	short		*qtab){	unsigned char	sp;	/* A-law compressed 8-bit code */	short		dx;	/* prediction error */	char		id;	/* quantized prediction error */	int		sd;	/* adjusted A-law decoded sample value */	int		im;	/* biased magnitude of i */	int		imx;	/* biased magnitude of id */	if (sr <= -32768)		sr = -1;	sp = linear2alaw((sr >> 1) << 3);	/* short to A-law compression */	dx = (alaw2linear(sp) >> 2) - se;	/* 16-bit prediction error */	id = quantize(dx, y, qtab, sign - 1);	if (id == i) {			/* no adjustment on sp */		return (sp);	} else {			/* sp adjustment needed */		/* ADPCM codes : 8, 9, ... F, 0, 1, ... , 6, 7 */		im = i ^ sign;		/* 2's complement to biased unsigned */		imx = id ^ sign;		if (imx > im) {		/* sp adjusted to next lower value */			if (sp & 0x80) {				sd = (sp == 0xD5) ? 0x55 :				    ((sp ^ 0x55) - 1) ^ 0x55;			} else {				sd = (sp == 0x2A) ? 0x2A :				    ((sp ^ 0x55) + 1) ^ 0x55;			}		} else {		/* sp adjusted to next higher value */			if (sp & 0x80)				sd = (sp == 0xAA) ? 0xAA :				    ((sp ^ 0x55) + 1) ^ 0x55;			else				sd = (sp == 0x55) ? 0xD5 :				    ((sp ^ 0x55) - 1) ^ 0x55;		}		return (sd);	}}inttandem_adjust_ulaw(	int		sr,	/* decoder output linear PCM sample */	int		se,	/* predictor estimate sample */	int		y,	/* quantizer step size */	int		i,	/* decoder input code */	int		sign,	short		*qtab){	unsigned char	sp;	/* u-law compressed 8-bit code */	short		dx;	/* prediction error */	char		id;	/* quantized prediction error */	int		sd;	/* adjusted u-law decoded sample value */	int		im;	/* biased magnitude of i */	int		imx;	/* biased magnitude of id */	if (sr <= -32768)		sr = 0;	sp = linear2ulaw(sr << 2);	/* short to u-law compression */	dx = (ulaw2linear(sp) >> 2) - se;	/* 16-bit prediction error */	id = quantize(dx, y, qtab, sign - 1);	if (id == i) {		return (sp);	} else {		/* ADPCM codes : 8, 9, ... F, 0, 1, ... , 6, 7 */		im = i ^ sign;		/* 2's complement to biased unsigned */		imx = id ^ sign;		if (imx > im) {		/* sp adjusted to next lower value */			if (sp & 0x80)				sd = (sp == 0xFF) ? 0x7E : sp + 1;			else				sd = (sp == 0) ? 0 : sp - 1;		} else {		/* sp adjusted to next higher value */			if (sp & 0x80)				sd = (sp == 0x80) ? 0x80 : sp - 1;			else				sd = (sp == 0x7F) ? 0xFE : sp + 1;		}		return (sd);	}}