[wxWidgets.git] / contrib / src / mmedia / g711.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
 */

#include "wx/wxprec.h"

/*
 * g711.c
 *
 * u-law, A-law and linear PCM conversions.
 */
#define    SIGN_BIT    (0x80)        /* Sign bit for a A-law byte. */
#define    QUANT_MASK  (0xf)         /* Quantization field mask. */
#define    NSEGS       (8)           /* Number of A-law segments. */
#define    SEG_SHIFT   (4)           /* Left shift for segment number. */
#define    SEG_MASK    (0x70)        /* Segment field mask. */

static short seg_end[8] = {0xFF, 0x1FF, 0x3FF, 0x7FF,
                           0xFFF, 0x1FFF, 0x3FFF, 0x7FFF};

/* copy from CCITT G.711 specifications */
unsigned char _u2a[128] = {            /* u- to A-law conversions */
     1,     1,     2,     2,     3,     3,     4,     4,
     5,     5,     6,     6,     7,     7,     8,     8,
     9,    10,    11,    12,    13,    14,    15,    16,
    17,    18,    19,    20,    21,    22,    23,    24,
    25,    27,    29,    31,    33,    34,    35,    36,
    37,    38,    39,    40,    41,    42,    43,    44,
    46,    48,    49,    50,    51,    52,    53,    54,
    55,    56,    57,    58,    59,    60,    61,    62,
    64,    65,    66,    67,    68,    69,    70,    71,
    72,    73,    74,    75,    76,    77,    78,    79,
    81,    82,    83,    84,    85,    86,    87,    88,
    89,    90,    91,    92,    93,    94,    95,    96,
    97,    98,    99,   100,   101,   102,   103,   104,
   105,   106,   107,   108,   109,   110,   111,   112,
   113,   114,   115,   116,   117,   118,   119,   120,
   121,   122,   123,   124,   125,   126,   127,   128};

unsigned char _a2u[128] = {            /* A- to u-law conversions */
     1,     3,     5,     7,     9,    11,    13,    15,
    16,    17,    18,    19,    20,    21,    22,    23,
    24,    25,    26,    27,    28,    29,    30,    31,
    32,    32,    33,    33,    34,    34,    35,    35,
    36,    37,    38,    39,    40,    41,    42,    43,
    44,    45,    46,    47,    48,    48,    49,    49,
    50,    51,    52,    53,    54,    55,    56,    57,
    58,    59,    60,    61,    62,    63,    64,    64,
    65,    66,    67,    68,    69,    70,    71,    72,
    73,    74,    75,    76,    77,    78,    79,    79,
    80,    81,    82,    83,    84,    85,    86,    87,
    88,    89,    90,    91,    92,    93,    94,    95,
    96,    97,    98,    99,   100,   101,   102,   103,
   104,   105,   106,   107,   108,   109,   110,   111,
   112,   113,   114,   115,   116,   117,   118,   119,
   120,   121,   122,   123,   124,   125,   126,   127};

static int
search(
    int        val,
    short     *table,
    int        size)
{
    int i;

    for (i = 0; i < size; i++) {
        if (val <= *table++)
            return (i);
    }
    return (size);
}

/*
 * linear2alaw() - Convert a 16-bit linear PCM value to 8-bit A-law
 *
 * linear2alaw() accepts an 16-bit integer and encodes it as A-law data.
 *
 *        Linear Input Code       Compressed Code
 *    ------------------------    ---------------
 *    0000000wxyza                    000wxyz
 *    0000001wxyza                    001wxyz
 *    000001wxyzab                    010wxyz
 *    00001wxyzabc                    011wxyz
 *    0001wxyzabcd                    100wxyz
 *    001wxyzabcde                    101wxyz
 *    01wxyzabcdef                    110wxyz
 *    1wxyzabcdefg                    111wxyz
 *
 * For further information see John C. Bellamy's Digital Telephony, 1982,
 * John Wiley & Sons, pps 98-111 and 472-476.
 */
unsigned char
linear2alaw(
    int        pcm_val)    /* 2's complement (16-bit range) */
{
    int              mask;
    int              seg;
    unsigned char    aval;

    if (pcm_val >= 0) {
        mask = 0xD5;        /* sign (7th) bit = 1 */
    } else {
        mask = 0x55;        /* sign bit = 0 */
        pcm_val = -pcm_val - 8;
    }

    /* Convert the scaled magnitude to segment number. */
    seg = search(pcm_val, seg_end, 8);

    /* Combine the sign, segment, and quantization bits. */

    if (seg >= 8)        /* out of range, return maximum value. */
        return (0x7F ^ mask);
    else {
        aval = seg << SEG_SHIFT;
        if (seg < 2)
            aval |= (pcm_val >> 4) & QUANT_MASK;
        else
            aval |= (pcm_val >> (seg + 3)) & QUANT_MASK;
        return (aval ^ mask);
    }
}

/*
 * alaw2linear() - Convert an A-law value to 16-bit linear PCM
 *
 */
int
alaw2linear(
    unsigned char    a_val)
{
    int        t;
    int        seg;

    a_val ^= 0x55;

    t = (a_val & QUANT_MASK) << 4;
    seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT;
    switch (seg) {
    case 0:
        t += 8;
        break;
    case 1:
        t += 0x108;
        break;
    default:
        t += 0x108;
        t <<= seg - 1;
    }
    return ((a_val & SIGN_BIT) ? t : -t);
}

#define    BIAS        (0x84)        /* Bias for linear code. */

/*
 * linear2ulaw() - Convert a linear PCM value to u-law
 *
 * In order to simplify the encoding process, the original linear magnitude
 * is biased by adding 33 which shifts the encoding range from (0 - 8158) to
 * (33 - 8191). The result can be seen in the following encoding table:
 *
 *    Biased Linear Input Code    Compressed Code
 *    ------------------------    ---------------
 *    00000001wxyza                   000wxyz
 *    0000001wxyzab                   001wxyz
 *    000001wxyzabc                   010wxyz
 *    00001wxyzabcd                   011wxyz
 *    0001wxyzabcde                   100wxyz
 *    001wxyzabcdef                   101wxyz
 *    01wxyzabcdefg                   110wxyz
 *    1wxyzabcdefgh                   111wxyz
 *
 * Each biased linear code has a leading 1 which identifies the segment
 * number. The value of the segment number is equal to 7 minus the number
 * of leading 0's. The quantization interval is directly available as the
 * four bits wxyz.  * The trailing bits (a - h) are ignored.
 *
 * Ordinarily the complement of the resulting code word is used for
 * transmission, and so the code word is complemented before it is returned.
 *
 * For further information see John C. Bellamy's Digital Telephony, 1982,
 * John Wiley & Sons, pps 98-111 and 472-476.
 */
unsigned char
linear2ulaw(
    int        pcm_val)    /* 2's complement (16-bit range) */
{
    int              mask;
    int              seg;
    unsigned char    uval;

    /* Get the sign and the magnitude of the value. */
    if (pcm_val < 0) {
        pcm_val = BIAS - pcm_val;
        mask = 0x7F;
    } else {
        pcm_val += BIAS;
        mask = 0xFF;
    }

    /* Convert the scaled magnitude to segment number. */
    seg = search(pcm_val, seg_end, 8);

    /*
     * Combine the sign, segment, quantization bits;
     * and complement the code word.
     */
    if (seg >= 8)        /* out of range, return maximum value. */
        return (0x7F ^ mask);
    else {
        uval = (seg << 4) | ((pcm_val >> (seg + 3)) & 0xF);
        return (uval ^ mask);
    }

}

/*
 * ulaw2linear() - Convert a u-law value to 16-bit linear PCM
 *
 * First, a biased linear code is derived from the code word. An unbiased
 * output can then be obtained by subtracting 33 from the biased code.
 *
 * Note that this function expects to be passed the complement of the
 * original code word. This is in keeping with ISDN conventions.
 */
int
ulaw2linear(
    unsigned char    u_val)
{
    int t;

    /* Complement to obtain normal u-law value. */
    u_val = ~u_val;

    /*
     * Extract and bias the quantization bits. Then
     * shift up by the segment number and subtract out the bias.
     */
    t = ((u_val & QUANT_MASK) << 3) + BIAS;
    t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT;

    return ((u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS));
}

/* A-law to u-law conversion */
unsigned char
alaw2ulaw(
    unsigned char    aval)
{
    aval &= 0xff;
    return ((aval & 0x80) ? (0xFF ^ _a2u[aval ^ 0xD5]) :
        (0x7F ^ _a2u[aval ^ 0x55]));
}

/* u-law to A-law conversion */
unsigned char
ulaw2alaw(
    unsigned char    uval)
{
    uval &= 0xff;
    return ((uval & 0x80) ? (0xD5 ^ (_u2a[0xFF ^ uval] - 1)) :
        (0x55 ^ (_u2a[0x7F ^ uval] - 1)));
}
Commit	Line	Data
e8482f24 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
92a19c2e	27	#include "wx/wxprec.h"
e8482f24 GL	28
	29	/*
	30	* g711.c
	31	*
	32	* u-law, A-law and linear PCM conversions.
	33	*/
dea7e44a WS	34	#define SIGN_BIT (0x80) /* Sign bit for a A-law byte. */
	35	#define QUANT_MASK (0xf) /* Quantization field mask. */
	36	#define NSEGS (8) /* Number of A-law segments. */
	37	#define SEG_SHIFT (4) /* Left shift for segment number. */
	38	#define SEG_MASK (0x70) /* Segment field mask. */
e8482f24 GL	39
e8482f24 GL	40	static short seg_end[8] = {0xFF, 0x1FF, 0x3FF, 0x7FF,
dea7e44a	41	0xFFF, 0x1FFF, 0x3FFF, 0x7FFF};
e8482f24 GL	42
e8482f24 GL	43	/* copy from CCITT G.711 specifications */
dea7e44a WS	44	unsigned char _u2a[128] = { /* u- to A-law conversions */
	45	1, 1, 2, 2, 3, 3, 4, 4,
	46	5, 5, 6, 6, 7, 7, 8, 8,
	47	9, 10, 11, 12, 13, 14, 15, 16,
	48	17, 18, 19, 20, 21, 22, 23, 24,
	49	25, 27, 29, 31, 33, 34, 35, 36,
	50	37, 38, 39, 40, 41, 42, 43, 44,
	51	46, 48, 49, 50, 51, 52, 53, 54,
	52	55, 56, 57, 58, 59, 60, 61, 62,
	53	64, 65, 66, 67, 68, 69, 70, 71,
	54	72, 73, 74, 75, 76, 77, 78, 79,
	55	81, 82, 83, 84, 85, 86, 87, 88,
	56	89, 90, 91, 92, 93, 94, 95, 96,
	57	97, 98, 99, 100, 101, 102, 103, 104,
	58	105, 106, 107, 108, 109, 110, 111, 112,
	59	113, 114, 115, 116, 117, 118, 119, 120,
	60	121, 122, 123, 124, 125, 126, 127, 128};
e8482f24	61
dea7e44a WS	62	unsigned char _a2u[128] = { /* A- to u-law conversions */
	63	1, 3, 5, 7, 9, 11, 13, 15,
	64	16, 17, 18, 19, 20, 21, 22, 23,
	65	24, 25, 26, 27, 28, 29, 30, 31,
	66	32, 32, 33, 33, 34, 34, 35, 35,
	67	36, 37, 38, 39, 40, 41, 42, 43,
	68	44, 45, 46, 47, 48, 48, 49, 49,
	69	50, 51, 52, 53, 54, 55, 56, 57,
	70	58, 59, 60, 61, 62, 63, 64, 64,
	71	65, 66, 67, 68, 69, 70, 71, 72,
	72	73, 74, 75, 76, 77, 78, 79, 79,
	73	80, 81, 82, 83, 84, 85, 86, 87,
	74	88, 89, 90, 91, 92, 93, 94, 95,
	75	96, 97, 98, 99, 100, 101, 102, 103,
	76	104, 105, 106, 107, 108, 109, 110, 111,
	77	112, 113, 114, 115, 116, 117, 118, 119,
	78	120, 121, 122, 123, 124, 125, 126, 127};
e8482f24 GL	79
	80	static int
	81	search(
dea7e44a WS	82	int val,
	83	short *table,
	84	int size)
e8482f24	85	{
dea7e44a	86	int i;
e8482f24	87
dea7e44a WS	88	for (i = 0; i < size; i++) {
	89	if (val <= *table++)
	90	return (i);
	91	}
	92	return (size);
e8482f24 GL	93	}
	94
	95	/*
	96	* linear2alaw() - Convert a 16-bit linear PCM value to 8-bit A-law
	97	*
	98	* linear2alaw() accepts an 16-bit integer and encodes it as A-law data.
	99	*
dea7e44a WS	100	* Linear Input Code Compressed Code
	101	* ------------------------ ---------------
	102	* 0000000wxyza 000wxyz
	103	* 0000001wxyza 001wxyz
	104	* 000001wxyzab 010wxyz
	105	* 00001wxyzabc 011wxyz
	106	* 0001wxyzabcd 100wxyz
	107	* 001wxyzabcde 101wxyz
	108	* 01wxyzabcdef 110wxyz
	109	* 1wxyzabcdefg 111wxyz
e8482f24 GL	110	*
	111	* For further information see John C. Bellamy's Digital Telephony, 1982,
	112	* John Wiley & Sons, pps 98-111 and 472-476.
	113	*/
	114	unsigned char
	115	linear2alaw(
dea7e44a	116	int pcm_val) /* 2's complement (16-bit range) */
e8482f24	117	{
dea7e44a WS	118	int mask;
	119	int seg;
	120	unsigned char aval;
e8482f24	121
dea7e44a WS	122	if (pcm_val >= 0) {
	123	mask = 0xD5; /* sign (7th) bit = 1 */
	124	} else {
	125	mask = 0x55; /* sign bit = 0 */
	126	pcm_val = -pcm_val - 8;
	127	}
e8482f24	128
dea7e44a WS	129	/* Convert the scaled magnitude to segment number. */
dea7e44a WS	130	seg = search(pcm_val, seg_end, 8);
e8482f24	131
dea7e44a	132	/* Combine the sign, segment, and quantization bits. */
e8482f24	133
dea7e44a WS	134	if (seg >= 8) /* out of range, return maximum value. */
	135	return (0x7F ^ mask);
	136	else {
	137	aval = seg << SEG_SHIFT;
	138	if (seg < 2)
	139	aval \|= (pcm_val >> 4) & QUANT_MASK;
	140	else
	141	aval \|= (pcm_val >> (seg + 3)) & QUANT_MASK;
	142	return (aval ^ mask);
	143	}
e8482f24 GL	144	}
	145
	146	/*
	147	* alaw2linear() - Convert an A-law value to 16-bit linear PCM
	148	*
	149	*/
	150	int
	151	alaw2linear(
dea7e44a	152	unsigned char a_val)
e8482f24	153	{
dea7e44a WS	154	int t;
dea7e44a WS	155	int seg;
e8482f24	156
dea7e44a	157	a_val ^= 0x55;
e8482f24	158
dea7e44a WS	159	t = (a_val & QUANT_MASK) << 4;
	160	seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT;
	161	switch (seg) {
	162	case 0:
	163	t += 8;
	164	break;
	165	case 1:
	166	t += 0x108;
	167	break;
	168	default:
	169	t += 0x108;
	170	t <<= seg - 1;
	171	}
	172	return ((a_val & SIGN_BIT) ? t : -t);
e8482f24 GL	173	}
e8482f24 GL	174
dea7e44a	175	#define BIAS (0x84) /* Bias for linear code. */
e8482f24 GL	176
	177	/*
	178	* linear2ulaw() - Convert a linear PCM value to u-law
	179	*
	180	* In order to simplify the encoding process, the original linear magnitude
	181	* is biased by adding 33 which shifts the encoding range from (0 - 8158) to
	182	* (33 - 8191). The result can be seen in the following encoding table:
	183	*
dea7e44a WS	184	* Biased Linear Input Code Compressed Code
	185	* ------------------------ ---------------
	186	* 00000001wxyza 000wxyz
	187	* 0000001wxyzab 001wxyz
	188	* 000001wxyzabc 010wxyz
	189	* 00001wxyzabcd 011wxyz
	190	* 0001wxyzabcde 100wxyz
	191	* 001wxyzabcdef 101wxyz
	192	* 01wxyzabcdefg 110wxyz
	193	* 1wxyzabcdefgh 111wxyz
e8482f24 GL	194	*
	195	* Each biased linear code has a leading 1 which identifies the segment
	196	* number. The value of the segment number is equal to 7 minus the number
	197	* of leading 0's. The quantization interval is directly available as the
	198	* four bits wxyz. * The trailing bits (a - h) are ignored.
	199	*
	200	* Ordinarily the complement of the resulting code word is used for
	201	* transmission, and so the code word is complemented before it is returned.
	202	*
	203	* For further information see John C. Bellamy's Digital Telephony, 1982,
	204	* John Wiley & Sons, pps 98-111 and 472-476.
	205	*/
	206	unsigned char
	207	linear2ulaw(
dea7e44a	208	int pcm_val) /* 2's complement (16-bit range) */
e8482f24	209	{
dea7e44a WS	210	int mask;
	211	int seg;
	212	unsigned char uval;
e8482f24	213
dea7e44a WS	214	/* Get the sign and the magnitude of the value. */
	215	if (pcm_val < 0) {
	216	pcm_val = BIAS - pcm_val;
	217	mask = 0x7F;
	218	} else {
	219	pcm_val += BIAS;
	220	mask = 0xFF;
	221	}
e8482f24	222
dea7e44a WS	223	/* Convert the scaled magnitude to segment number. */
dea7e44a WS	224	seg = search(pcm_val, seg_end, 8);
e8482f24	225
dea7e44a WS	226	/*
	227	* Combine the sign, segment, quantization bits;
	228	* and complement the code word.
	229	*/
	230	if (seg >= 8) /* out of range, return maximum value. */
	231	return (0x7F ^ mask);
	232	else {
	233	uval = (seg << 4) \| ((pcm_val >> (seg + 3)) & 0xF);
	234	return (uval ^ mask);
	235	}
e8482f24 GL	236
	237	}
	238
	239	/*
	240	* ulaw2linear() - Convert a u-law value to 16-bit linear PCM
	241	*
	242	* First, a biased linear code is derived from the code word. An unbiased
	243	* output can then be obtained by subtracting 33 from the biased code.
	244	*
	245	* Note that this function expects to be passed the complement of the
	246	* original code word. This is in keeping with ISDN conventions.
	247	*/
	248	int
	249	ulaw2linear(
dea7e44a	250	unsigned char u_val)
e8482f24	251	{
dea7e44a	252	int t;
e8482f24	253
dea7e44a WS	254	/* Complement to obtain normal u-law value. */
dea7e44a WS	255	u_val = ~u_val;
e8482f24	256
dea7e44a WS	257	/*
	258	* Extract and bias the quantization bits. Then
	259	* shift up by the segment number and subtract out the bias.
	260	*/
	261	t = ((u_val & QUANT_MASK) << 3) + BIAS;
	262	t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT;
e8482f24	263
dea7e44a	264	return ((u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS));
e8482f24 GL	265	}
	266
	267	/* A-law to u-law conversion */
	268	unsigned char
	269	alaw2ulaw(
dea7e44a	270	unsigned char aval)
e8482f24	271	{
dea7e44a WS	272	aval &= 0xff;
	273	return ((aval & 0x80) ? (0xFF ^ _a2u[aval ^ 0xD5]) :
	274	(0x7F ^ _a2u[aval ^ 0x55]));
e8482f24 GL	275	}
	276
	277	/* u-law to A-law conversion */
	278	unsigned char
	279	ulaw2alaw(
dea7e44a	280	unsigned char uval)
e8482f24	281	{
dea7e44a WS	282	uval &= 0xff;
	283	return ((uval & 0x80) ? (0xD5 ^ (_u2a[0xFF ^ uval] - 1)) :
	284	(0x55 ^ (_u2a[0x7F ^ uval] - 1)));
e8482f24	285	}