[wxWidgets.git] / utils / wxMMedia2 / lib / g723_24.cpp

/*
 * 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
 */

/*
 * g723_24.c
 *
 * Description:
 *
 * g723_24_encoder(), g723_24_decoder()
 *
 * These routines comprise an implementation of the CCITT G.723 24 Kbps
 * ADPCM coding algorithm.  Essentially, this implementation is identical to
 * the bit level description except for a few deviations which take advantage
 * of workstation attributes, such as hardware 2's complement arithmetic.
 *
 */
#include "g72x.h"

/*
 * Maps G.723_24 code word to reconstructed scale factor normalized log
 * magnitude values.
 */
static short	_dqlntab[8] = {-2048, 135, 273, 373, 373, 273, 135, -2048};

/* Maps G.723_24 code word to log of scale factor multiplier. */
static short	_witab[8] = {-128, 960, 4384, 18624, 18624, 4384, 960, -128};

/*
 * Maps G.723_24 code words to a set of values whose long and short
 * term averages are computed and then compared to give an indication
 * how stationary (steady state) the signal is.
 */
static short	_fitab[8] = {0, 0x200, 0x400, 0xE00, 0xE00, 0x400, 0x200, 0};

static short qtab_723_24[3] = {8, 218, 331};

/*
 * g723_24_encoder()
 *
 * Encodes a linear PCM, A-law or u-law input sample and returns its 3-bit code.
 * Returns -1 if invalid input coding value.
 */
int
g723_24_encoder(
	int		sl,
	int		in_coding,
	struct g72x_state *state_ptr)
{
	short		sei, sezi, se, sez;	/* ACCUM */
	short		d;			/* SUBTA */
	short		y;			/* MIX */
	short		sr;			/* ADDB */
	short		dqsez;			/* ADDC */
	short		dq, i;

	switch (in_coding) {	/* linearize input sample to 14-bit PCM */
	case AUDIO_ENCODING_ALAW:
		sl = alaw2linear(sl) >> 2;
		break;
	case AUDIO_ENCODING_ULAW:
		sl = ulaw2linear(sl) >> 2;
		break;
	case AUDIO_ENCODING_LINEAR:
		sl = ((short)sl) >> 2;		/* sl of 14-bit dynamic range */
		break;
	default:
		return (-1);
	}

	sezi = predictor_zero(state_ptr);
	sez = sezi >> 1;
	sei = sezi + predictor_pole(state_ptr);
	se = sei >> 1;			/* se = estimated signal */

	d = sl - se;			/* d = estimation diff. */

	/* quantize prediction difference d */
	y = step_size(state_ptr);	/* quantizer step size */
	i = quantize(d, y, qtab_723_24, 3);	/* i = ADPCM code */
	dq = reconstruct(i & 4, _dqlntab[i], y); /* quantized diff. */

	sr = (dq < 0) ? se - (dq & 0x3FFF) : se + dq; /* reconstructed signal */

	dqsez = sr + sez - se;		/* pole prediction diff. */

	update(3, y, _witab[i], _fitab[i], dq, sr, dqsez, state_ptr);

	return (i);
}

/*
 * g723_24_decoder()
 *
 * Decodes a 3-bit CCITT G.723_24 ADPCM code and returns
 * the resulting 16-bit linear PCM, A-law or u-law sample value.
 * -1 is returned if the output coding is unknown.
 */
int
g723_24_decoder(
	int		i,
	int		out_coding,
	struct g72x_state *state_ptr)
{
	short		sezi, sei, sez, se;	/* ACCUM */
	short		y;			/* MIX */
	short		sr;			/* ADDB */
	short		dq;
	short		dqsez;

	i &= 0x07;			/* mask to get proper bits */
	sezi = predictor_zero(state_ptr);
	sez = sezi >> 1;
	sei = sezi + predictor_pole(state_ptr);
	se = sei >> 1;			/* se = estimated signal */

	y = step_size(state_ptr);	/* adaptive quantizer step size */
	dq = reconstruct(i & 0x04, _dqlntab[i], y); /* unquantize pred diff */

	sr = (dq < 0) ? (se - (dq & 0x3FFF)) : (se + dq); /* reconst. signal */

	dqsez = sr - se + sez;			/* pole prediction diff. */

	update(3, y, _witab[i], _fitab[i], dq, sr, dqsez, state_ptr);

	switch (out_coding) {
	case AUDIO_ENCODING_ALAW:
		return (tandem_adjust_alaw(sr, se, y, i, 4, qtab_723_24));
	case AUDIO_ENCODING_ULAW:
		return (tandem_adjust_ulaw(sr, se, y, i, 4, qtab_723_24));
	case AUDIO_ENCODING_LINEAR:
		return (sr << 2);	/* sr was of 14-bit dynamic range */
	default:
		return (-1);
	}
}
Commit	Line	Data
4d6306eb GL	1	/*
	2	* This source code is a product of Sun Microsystems, Inc. and is provided
	3	* for unrestricted use. Users may copy or modify this source code without
	4	* charge.
	5	*
	6	* SUN SOURCE CODE IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING
	7	* THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
	8	* PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
	9	*
	10	* Sun source code is provided with no support and without any obligation on
	11	* the part of Sun Microsystems, Inc. to assist in its use, correction,
	12	* modification or enhancement.
	13	*
	14	* SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
	15	* INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS SOFTWARE
	16	* OR ANY PART THEREOF.
	17	*
	18	* In no event will Sun Microsystems, Inc. be liable for any lost revenue
	19	* or profits or other special, indirect and consequential damages, even if
	20	* Sun has been advised of the possibility of such damages.
	21	*
	22	* Sun Microsystems, Inc.
	23	* 2550 Garcia Avenue
	24	* Mountain View, California 94043
	25	*/
	26
	27	/*
	28	* g723_24.c
	29	*
	30	* Description:
	31	*
	32	* g723_24_encoder(), g723_24_decoder()
	33	*
	34	* These routines comprise an implementation of the CCITT G.723 24 Kbps
	35	* ADPCM coding algorithm. Essentially, this implementation is identical to
	36	* the bit level description except for a few deviations which take advantage
	37	* of workstation attributes, such as hardware 2's complement arithmetic.
	38	*
	39	*/
	40	#include "g72x.h"
	41
	42	/*
	43	* Maps G.723_24 code word to reconstructed scale factor normalized log
	44	* magnitude values.
	45	*/
	46	static short _dqlntab[8] = {-2048, 135, 273, 373, 373, 273, 135, -2048};
	47
	48	/* Maps G.723_24 code word to log of scale factor multiplier. */
	49	static short _witab[8] = {-128, 960, 4384, 18624, 18624, 4384, 960, -128};
	50
	51	/*
	52	* Maps G.723_24 code words to a set of values whose long and short
	53	* term averages are computed and then compared to give an indication
	54	* how stationary (steady state) the signal is.
	55	*/
	56	static short _fitab[8] = {0, 0x200, 0x400, 0xE00, 0xE00, 0x400, 0x200, 0};
	57
	58	static short qtab_723_24[3] = {8, 218, 331};
	59
	60	/*
	61	* g723_24_encoder()
	62	*
	63	* Encodes a linear PCM, A-law or u-law input sample and returns its 3-bit code.
	64	* Returns -1 if invalid input coding value.
65	*/
66	int
67	g723_24_encoder(
68	int sl,
69	int in_coding,
70	struct g72x_state *state_ptr)
71	{
72	short sei, sezi, se, sez; /* ACCUM */
73	short d; /* SUBTA */
74	short y; /* MIX */
75	short sr; /* ADDB */
76	short dqsez; /* ADDC */
77	short dq, i;
78
79	switch (in_coding) { /* linearize input sample to 14-bit PCM */
80	case AUDIO_ENCODING_ALAW:
81	sl = alaw2linear(sl) >> 2;
82	break;
83	case AUDIO_ENCODING_ULAW:
84	sl = ulaw2linear(sl) >> 2;
85	break;
86	case AUDIO_ENCODING_LINEAR:
87	sl = ((short)sl) >> 2; /* sl of 14-bit dynamic range */
88	break;
89	default:
90	return (-1);
91	}
92
93	sezi = predictor_zero(state_ptr);
94	sez = sezi >> 1;
95	sei = sezi + predictor_pole(state_ptr);
96	se = sei >> 1; /* se = estimated signal */
97
98	d = sl - se; /* d = estimation diff. */
99
100	/* quantize prediction difference d */
101	y = step_size(state_ptr); /* quantizer step size */
102	i = quantize(d, y, qtab_723_24, 3); /* i = ADPCM code */
103	dq = reconstruct(i & 4, _dqlntab[i], y); /* quantized diff. */
104
105	sr = (dq < 0) ? se - (dq & 0x3FFF) : se + dq; /* reconstructed signal */
106
107	dqsez = sr + sez - se; /* pole prediction diff. */
108
109	update(3, y, _witab[i], _fitab[i], dq, sr, dqsez, state_ptr);
110
111	return (i);
112	}
113
114	/*
115	* g723_24_decoder()
116	*
117	* Decodes a 3-bit CCITT G.723_24 ADPCM code and returns
118	* the resulting 16-bit linear PCM, A-law or u-law sample value.
119	* -1 is returned if the output coding is unknown.
120	*/
121	int
122	g723_24_decoder(
123	int i,
124	int out_coding,
125	struct g72x_state *state_ptr)
126	{
127	short sezi, sei, sez, se; /* ACCUM */
128	short y; /* MIX */
129	short sr; /* ADDB */
130	short dq;
131	short dqsez;
132
133	i &= 0x07; /* mask to get proper bits */
134	sezi = predictor_zero(state_ptr);
135	sez = sezi >> 1;
136	sei = sezi + predictor_pole(state_ptr);
137	se = sei >> 1; /* se = estimated signal */
138
139	y = step_size(state_ptr); /* adaptive quantizer step size */
140	dq = reconstruct(i & 0x04, _dqlntab[i], y); /* unquantize pred diff */
141
142	sr = (dq < 0) ? (se - (dq & 0x3FFF)) : (se + dq); /* reconst. signal */
143
144	dqsez = sr - se + sez; /* pole prediction diff. */
145
146	update(3, y, _witab[i], _fitab[i], dq, sr, dqsez, state_ptr);
147
148	switch (out_coding) {
149	case AUDIO_ENCODING_ALAW:
150	return (tandem_adjust_alaw(sr, se, y, i, 4, qtab_723_24));
151	case AUDIO_ENCODING_ULAW:
152	return (tandem_adjust_ulaw(sr, se, y, i, 4, qtab_723_24));
153	case AUDIO_ENCODING_LINEAR:
154	return (sr << 2); /* sr was of 14-bit dynamic range */
155	default:
156	return (-1);
157	}
158	}