view miscutil/gsm0610.c @ 465:003e48f8ebe1

rvinterf/etmsync/fsnew.c: cast 0 to (char *) for execl sentinel I generally don't use NULL and use plain 0 instead, based on a "NULL considered harmful" discussion on the classiccmp mailing list many aeons ago (I couldn't find it, and I reason that it must have been 2005 or earlier), but a recent complaint by a packager sent me searching, and I found this: https://ewontfix.com/11/ While I don't give a @#$% about "modern" systems and code-nazi tools, I realized that passing a plain 0 as a pointer sentinel in execl is wrong because it will break on systems where pointers are longer than the plain int type. Again, I don't give a @#$% about the abomination of x86_64 and the like, but if anyone ever manages to port my code to something like a PDP-11 (16-bit int, 32-bit long and pointers), then passing a plain 0 as a function argument where a pointer is expected most definitely won't work: if the most natural stack slot and SP alignment unit is 16 bits, fitting an int, with longs and pointers taking up two such slots, then the call stack will be totally wrong with a plain 0 passed for a pointer. Casting the 0 to (char *) ought to be the most kosher solution for the most retro systems possible.
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 11 Feb 2019 00:00:19 +0000
parents 08804864172a
children
line wrap: on
line source

/*
 * This code (lifted from OsmocomBB) facilitates the conversion of 33-byte
 * GSM 06.10 encoded speech frames between the bit order at the 06.10 interface
 * in the de facto standard libgsm implementation and the bit order at the
 * 05.03 channel encoder interface, as realized in TI's Calypso DSP.
 */

#include <sys/types.h>
#include <string.h>
#include <strings.h>

/* GSM FR - subjective importance bit ordering */
	/* This array encodes GSM 05.03 Table 2.
	 * It's also GSM 06.10 Table A.2.1a
	 *
	 * It converts between serial parameter output by the encoder and the
	 * order needed before channel encoding.
	 */
const u_short gsm0610_bitorder[260] = {
	0,	/* LARc0:5 */
	47,	/* Xmaxc0:5 */
	103,	/* Xmaxc1:5 */
	159,	/* Xmaxc2:5 */
	215,	/* Xmaxc3:5 */
	1,	/* LARc0:4 */
	6,	/* LARc1:5 */
	12,	/* LARc2:4 */
	2,	/* LARc0:3 */
	7,	/* LARc1:4 */
	13,	/* LARc2:3 */
	17,	/* LARc3:4 */
	36,	/* Nc0:6 */
	92,	/* Nc1:6 */
	148,	/* Nc2:6 */
	204,	/* Nc3:6 */
	48,	/* Xmaxc0:4 */
	104,	/* Xmaxc1:4 */
	160,	/* Xmaxc2:4 */
	216,	/* Xmaxc3:4 */
	8,	/* LARc1:3 */
	22,	/* LARc4:3 */
	26,	/* LARc5:3 */
	37,	/* Nc0:5 */
	93,	/* Nc1:5 */
	149,	/* Nc2:5 */
	205,	/* Nc3:5 */
	38,	/* Nc0:4 */
	94,	/* Nc1:4 */
	150,	/* Nc2:4 */
	206,	/* Nc3:4 */
	39,	/* Nc0:3 */
	95,	/* Nc1:3 */
	151,	/* Nc2:3 */
	207,	/* Nc3:3 */
	40,	/* Nc0:2 */
	96,	/* Nc1:2 */
	152,	/* Nc2:2 */
	208,	/* Nc3:2 */
	49,	/* Xmaxc0:3 */
	105,	/* Xmaxc1:3 */
	161,	/* Xmaxc2:3 */
	217,	/* Xmaxc3:3 */
	3,	/* LARc0:2 */
	18,	/* LARc3:3 */
	30,	/* LARc6:2 */
	41,	/* Nc0:1 */
	97,	/* Nc1:1 */
	153,	/* Nc2:1 */
	209,	/* Nc3:1 */
	23,	/* LARc4:2 */
	27,	/* LARc5:2 */
	43,	/* bc0:1 */
	99,	/* bc1:1 */
	155,	/* bc2:1 */
	211,	/* bc3:1 */
	42,	/* Nc0:0 */
	98,	/* Nc1:0 */
	154,	/* Nc2:0 */
	210,	/* Nc3:0 */
	45,	/* Mc0:1 */
	101,	/* Mc1:1 */
	157,	/* Mc2:1 */
	213,	/* Mc3:1 */
	4,	/* LARc0:1 */
	9,	/* LARc1:2 */
	14,	/* LARc2:2 */
	33,	/* LARc7:2 */
	19,	/* LARc3:2 */
	24,	/* LARc4:1 */
	31,	/* LARc6:1 */
	44,	/* bc0:0 */
	100,	/* bc1:0 */
	156,	/* bc2:0 */
	212,	/* bc3:0 */
	50,	/* Xmaxc0:2 */
	106,	/* Xmaxc1:2 */
	162,	/* Xmaxc2:2 */
	218,	/* Xmaxc3:2 */
	53,	/* xmc0_0:2 */
	56,	/* xmc0_1:2 */
	59,	/* xmc0_2:2 */
	62,	/* xmc0_3:2 */
	65,	/* xmc0_4:2 */
	68,	/* xmc0_5:2 */
	71,	/* xmc0_6:2 */
	74,	/* xmc0_7:2 */
	77,	/* xmc0_8:2 */
	80,	/* xmc0_9:2 */
	83,	/* xmc0_10:2 */
	86,	/* xmc0_11:2 */
	89,	/* xmc0_12:2 */
	109,	/* xmc1_0:2 */
	112,	/* xmc1_1:2 */
	115,	/* xmc1_2:2 */
	118,	/* xmc1_3:2 */
	121,	/* xmc1_4:2 */
	124,	/* xmc1_5:2 */
	127,	/* xmc1_6:2 */
	130,	/* xmc1_7:2 */
	133,	/* xmc1_8:2 */
	136,	/* xmc1_9:2 */
	139,	/* xmc1_10:2 */
	142,	/* xmc1_11:2 */
	145,	/* xmc1_12:2 */
	165,	/* xmc2_0:2 */
	168,	/* xmc2_1:2 */
	171,	/* xmc2_2:2 */
	174,	/* xmc2_3:2 */
	177,	/* xmc2_4:2 */
	180,	/* xmc2_5:2 */
	183,	/* xmc2_6:2 */
	186,	/* xmc2_7:2 */
	189,	/* xmc2_8:2 */
	192,	/* xmc2_9:2 */
	195,	/* xmc2_10:2 */
	198,	/* xmc2_11:2 */
	201,	/* xmc2_12:2 */
	221,	/* xmc3_0:2 */
	224,	/* xmc3_1:2 */
	227,	/* xmc3_2:2 */
	230,	/* xmc3_3:2 */
	233,	/* xmc3_4:2 */
	236,	/* xmc3_5:2 */
	239,	/* xmc3_6:2 */
	242,	/* xmc3_7:2 */
	245,	/* xmc3_8:2 */
	248,	/* xmc3_9:2 */
	251,	/* xmc3_10:2 */
	254,	/* xmc3_11:2 */
	257,	/* xmc3_12:2 */
	46,	/* Mc0:0 */
	102,	/* Mc1:0 */
	158,	/* Mc2:0 */
	214,	/* Mc3:0 */
	51,	/* Xmaxc0:1 */
	107,	/* Xmaxc1:1 */
	163,	/* Xmaxc2:1 */
	219,	/* Xmaxc3:1 */
	54,	/* xmc0_0:1 */
	57,	/* xmc0_1:1 */
	60,	/* xmc0_2:1 */
	63,	/* xmc0_3:1 */
	66,	/* xmc0_4:1 */
	69,	/* xmc0_5:1 */
	72,	/* xmc0_6:1 */
	75,	/* xmc0_7:1 */
	78,	/* xmc0_8:1 */
	81,	/* xmc0_9:1 */
	84,	/* xmc0_10:1 */
	87,	/* xmc0_11:1 */
	90,	/* xmc0_12:1 */
	110,	/* xmc1_0:1 */
	113,	/* xmc1_1:1 */
	116,	/* xmc1_2:1 */
	119,	/* xmc1_3:1 */
	122,	/* xmc1_4:1 */
	125,	/* xmc1_5:1 */
	128,	/* xmc1_6:1 */
	131,	/* xmc1_7:1 */
	134,	/* xmc1_8:1 */
	137,	/* xmc1_9:1 */
	140,	/* xmc1_10:1 */
	143,	/* xmc1_11:1 */
	146,	/* xmc1_12:1 */
	166,	/* xmc2_0:1 */
	169,	/* xmc2_1:1 */
	172,	/* xmc2_2:1 */
	175,	/* xmc2_3:1 */
	178,	/* xmc2_4:1 */
	181,	/* xmc2_5:1 */
	184,	/* xmc2_6:1 */
	187,	/* xmc2_7:1 */
	190,	/* xmc2_8:1 */
	193,	/* xmc2_9:1 */
	196,	/* xmc2_10:1 */
	199,	/* xmc2_11:1 */
	202,	/* xmc2_12:1 */
	222,	/* xmc3_0:1 */
	225,	/* xmc3_1:1 */
	228,	/* xmc3_2:1 */
	231,	/* xmc3_3:1 */
	234,	/* xmc3_4:1 */
	237,	/* xmc3_5:1 */
	240,	/* xmc3_6:1 */
	243,	/* xmc3_7:1 */
	246,	/* xmc3_8:1 */
	249,	/* xmc3_9:1 */
	252,	/* xmc3_10:1 */
	255,	/* xmc3_11:1 */
	258,	/* xmc3_12:1 */
	5,	/* LARc0:0 */
	10,	/* LARc1:1 */
	15,	/* LARc2:1 */
	28,	/* LARc5:1 */
	32,	/* LARc6:0 */
	34,	/* LARc7:1 */
	35,	/* LARc7:0 */
	16,	/* LARc2:0 */
	20,	/* LARc3:1 */
	21,	/* LARc3:0 */
	25,	/* LARc4:0 */
	52,	/* Xmaxc0:0 */
	108,	/* Xmaxc1:0 */
	164,	/* Xmaxc2:0 */
	220,	/* Xmaxc3:0 */
	55,	/* xmc0_0:0 */
	58,	/* xmc0_1:0 */
	61,	/* xmc0_2:0 */
	64,	/* xmc0_3:0 */
	67,	/* xmc0_4:0 */
	70,	/* xmc0_5:0 */
	73,	/* xmc0_6:0 */
	76,	/* xmc0_7:0 */
	79,	/* xmc0_8:0 */
	82,	/* xmc0_9:0 */
	85,	/* xmc0_10:0 */
	88,	/* xmc0_11:0 */
	91,	/* xmc0_12:0 */
	111,	/* xmc1_0:0 */
	114,	/* xmc1_1:0 */
	117,	/* xmc1_2:0 */
	120,	/* xmc1_3:0 */
	123,	/* xmc1_4:0 */
	126,	/* xmc1_5:0 */
	129,	/* xmc1_6:0 */
	132,	/* xmc1_7:0 */
	135,	/* xmc1_8:0 */
	138,	/* xmc1_9:0 */
	141,	/* xmc1_10:0 */
	144,	/* xmc1_11:0 */
	147,	/* xmc1_12:0 */
	167,	/* xmc2_0:0 */
	170,	/* xmc2_1:0 */
	173,	/* xmc2_2:0 */
	176,	/* xmc2_3:0 */
	179,	/* xmc2_4:0 */
	182,	/* xmc2_5:0 */
	185,	/* xmc2_6:0 */
	188,	/* xmc2_7:0 */
	191,	/* xmc2_8:0 */
	194,	/* xmc2_9:0 */
	197,	/* xmc2_10:0 */
	200,	/* xmc2_11:0 */
	203,	/* xmc2_12:0 */
	223,	/* xmc3_0:0 */
	226,	/* xmc3_1:0 */
	229,	/* xmc3_2:0 */
	232,	/* xmc3_3:0 */
	235,	/* xmc3_4:0 */
	238,	/* xmc3_5:0 */
	241,	/* xmc3_6:0 */
	244,	/* xmc3_7:0 */
	247,	/* xmc3_8:0 */
	250,	/* xmc3_9:0 */
	253,	/* xmc3_10:0 */
	256,	/* xmc3_11:0 */
	259,	/* xmc3_12:0 */
	11,	/* LARc1:0 */
	29,	/* LARc5:0 */
};

static int
msb_get_bit(buf, bn)
	u_char *buf;
{
	int pos_byte = bn >> 3;
	int pos_bit  = 7 - (bn & 7);

	return (buf[pos_byte] >> pos_bit) & 1;
}

static void
msb_set_bit(buf, bn, bit)
	u_char *buf;
{
	int pos_byte = bn >> 3;
	int pos_bit  = 7 - (bn & 7);

	buf[pos_byte] |= (bit << pos_bit);
}

void
gsm0610_tidsp_to_libgsm(inbytes, outbytes)
	u_char *inbytes, *outbytes;
{
	int i, di, si;

	bzero(outbytes, 33);
	outbytes[0] = 0xD0;
	for (i = 0; i < 260; i++) {
		di = gsm0610_bitorder[i];
		si = (i > 181) ? i + 4 : i;
		msb_set_bit(outbytes, 4 + di, msb_get_bit(inbytes, si));
        }
}

void
gsm0610_libgsm_to_tidsp(inbytes, outbytes)
	u_char *inbytes, *outbytes;
{
	int i, di, si;

	bzero(outbytes, 33);
	for (i = 0; i < 260; i++) {
		si = gsm0610_bitorder[i];
		di = (i > 181) ? i + 4 : i;
		msb_set_bit(outbytes, di, msb_get_bit(inbytes, 4 + si));
        }
}