[libsigrok.git] / src / analog.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2014 Bert Vermeulen <bert@biot.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <config.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <ctype.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"

/** @cond PRIVATE */
#define LOG_PREFIX "analog"
/** @endcond */

/**
 * @file
 *
 * Handling and converting analog data.
 */

/**
 * @defgroup grp_analog Analog data handling
 *
 * Handling and converting analog data.
 *
 * @{
 */

struct unit_mq_string {
	uint64_t value;
	const char *str;
};

/* Please use the same order as in enum sr_unit (libsigrok.h). */
static struct unit_mq_string unit_strings[] = {
	{ SR_UNIT_VOLT, "V" },
	{ SR_UNIT_AMPERE, "A" },
	{ SR_UNIT_OHM, "\xe2\x84\xa6" },
	{ SR_UNIT_FARAD, "F" },
	{ SR_UNIT_KELVIN, "K" },
	{ SR_UNIT_CELSIUS, "\xc2\xb0""C" },
	{ SR_UNIT_FAHRENHEIT, "\xc2\xb0""F" },
	{ SR_UNIT_HERTZ, "Hz" },
	{ SR_UNIT_PERCENTAGE, "%" },
	{ SR_UNIT_BOOLEAN, "" },
	{ SR_UNIT_SECOND, "s" },
	{ SR_UNIT_SIEMENS, "S" },
	{ SR_UNIT_DECIBEL_MW, "dBu" },
	{ SR_UNIT_DECIBEL_VOLT, "dBv" },
	{ SR_UNIT_UNITLESS, "" },
	{ SR_UNIT_DECIBEL_SPL, "dB" },
	{ SR_UNIT_CONCENTRATION, "ppm" },
	{ SR_UNIT_REVOLUTIONS_PER_MINUTE, "RPM" },
	{ SR_UNIT_VOLT_AMPERE, "VA" },
	{ SR_UNIT_WATT, "W" },
	{ SR_UNIT_WATT_HOUR, "Wh" },
	{ SR_UNIT_METER_SECOND, "m/s" },
	{ SR_UNIT_HECTOPASCAL, "hPa" },
	{ SR_UNIT_HUMIDITY_293K, "%rF" },
	{ SR_UNIT_DEGREE, "\xc2\xb0" },
	{ SR_UNIT_HENRY, "H" },
	{ SR_UNIT_GRAM, "g" },
	{ SR_UNIT_CARAT, "ct" },
	{ SR_UNIT_OUNCE, "oz" },
	{ SR_UNIT_TROY_OUNCE, "oz t" },
	{ SR_UNIT_POUND, "lb" },
	{ SR_UNIT_PENNYWEIGHT, "dwt" },
	{ SR_UNIT_GRAIN, "gr" },
	{ SR_UNIT_TAEL, "tael" },
	{ SR_UNIT_MOMME, "momme" },
	{ SR_UNIT_TOLA, "tola" },
	{ SR_UNIT_PIECE, "pcs" },
	ALL_ZERO
};

/* Please use the same order as in enum sr_mqflag (libsigrok.h). */
static struct unit_mq_string mq_strings[] = {
	{ SR_MQFLAG_AC, " AC" },
	{ SR_MQFLAG_DC, " DC" },
	{ SR_MQFLAG_RMS, " RMS" },
	{ SR_MQFLAG_DIODE, " DIODE" },
	{ SR_MQFLAG_HOLD, " HOLD" },
	{ SR_MQFLAG_MAX, " MAX" },
	{ SR_MQFLAG_MIN, " MIN" },
	{ SR_MQFLAG_AUTORANGE, " AUTO" },
	{ SR_MQFLAG_RELATIVE, " REL" },
	{ SR_MQFLAG_SPL_FREQ_WEIGHT_A, "(A)" },
	{ SR_MQFLAG_SPL_FREQ_WEIGHT_C, "(C)" },
	{ SR_MQFLAG_SPL_FREQ_WEIGHT_Z, "(Z)" },
	{ SR_MQFLAG_SPL_FREQ_WEIGHT_FLAT, "(SPL)" },
	{ SR_MQFLAG_SPL_TIME_WEIGHT_S, " S" },
	{ SR_MQFLAG_SPL_TIME_WEIGHT_F, " F" },
	{ SR_MQFLAG_SPL_LAT, " LAT" },
	/* Not a standard function for SLMs, so this is a made-up notation. */
	{ SR_MQFLAG_SPL_PCT_OVER_ALARM, "%oA" },
	{ SR_MQFLAG_DURATION, " DURATION" },
	{ SR_MQFLAG_AVG, " AVG" },
	{ SR_MQFLAG_REFERENCE, " REF" },
	{ SR_MQFLAG_UNSTABLE, " UNSTABLE" },
	{ SR_MQFLAG_FOUR_WIRE, " 4-WIRE" },
	ALL_ZERO
};

SR_PRIV int sr_analog_init(struct sr_datafeed_analog *analog,
		struct sr_analog_encoding *encoding,
		struct sr_analog_meaning *meaning,
		struct sr_analog_spec *spec,
		int digits)
{
	memset(analog, 0, sizeof(*analog));
	memset(encoding, 0, sizeof(*encoding));
	memset(meaning, 0, sizeof(*meaning));
	memset(spec, 0, sizeof(*spec));

	analog->encoding = encoding;
	analog->meaning = meaning;
	analog->spec = spec;

	encoding->unitsize = sizeof(float);
	encoding->is_float = TRUE;
#ifdef WORDS_BIGENDIAN
	encoding->is_bigendian = TRUE;
#else
	encoding->is_bigendian = FALSE;
#endif
	encoding->digits = digits;
	encoding->is_digits_decimal = TRUE;
	encoding->scale.p = 1;
	encoding->scale.q = 1;
	encoding->offset.p = 0;
	encoding->offset.q = 1;

	spec->spec_digits = digits;

	return SR_OK;
}

/**
 * Convert an analog datafeed payload to an array of floats.
 *
 * @param[in] analog The analog payload to convert. Must not be NULL.
 *                   analog->data, analog->meaning, and analog->encoding
 *                   must not be NULL.
 * @param[out] outbuf Memory where to store the result. Must not be NULL.
 *
 * Sufficient memory for outbuf must have been pre-allocated by the caller,
 * who is also responsible for freeing it when no longer needed.
 *
 * @retval SR_OK Success.
 * @retval SR_ERR Unsupported encoding.
 * @retval SR_ERR_ARG Invalid argument.
 *
 * @since 0.4.0
 */
SR_API int sr_analog_to_float(const struct sr_datafeed_analog *analog,
		float *outbuf)
{
	float offset;
	unsigned int b, i, count;
	gboolean bigendian;

	if (!analog || !(analog->data) || !(analog->meaning)
			|| !(analog->encoding) || !outbuf)
		return SR_ERR_ARG;

	count = analog->num_samples * g_slist_length(analog->meaning->channels);

#ifdef WORDS_BIGENDIAN
	bigendian = TRUE;
#else
	bigendian = FALSE;
#endif
	if (!analog->encoding->is_float) {
		float offset = analog->encoding->offset.p / (float)analog->encoding->offset.q;
		float scale = analog->encoding->scale.p / (float)analog->encoding->scale.q;
		gboolean is_signed = analog->encoding->is_signed;
		gboolean is_bigendian = analog->encoding->is_bigendian;
		int8_t *data8 = (int8_t *)(analog->data);
		int16_t *data16 = (int16_t *)(analog->data);
		int32_t *data32 = (int32_t *)(analog->data);

		switch (analog->encoding->unitsize) {
		case 1:
			if (is_signed) {
				for (unsigned int i = 0; i < count; i++) {
					outbuf[i] = scale * data8[i];
					outbuf[i] += offset;
				}
			} else {
				for (unsigned int i = 0; i < count; i++) {
					outbuf[i] = scale * R8(data8 + i);
					outbuf[i] += offset;
				}
			}
			break;
		case 2:
			if (is_signed && is_bigendian) {
				for (unsigned int i = 0; i < count; i++) {
					outbuf[i] = scale * RB16S(&data16[i]);
					outbuf[i] += offset;
				}
			} else if (is_bigendian) {
				for (unsigned int i = 0; i < count; i++) {
					outbuf[i] = scale * RB16(&data16[i]);
					outbuf[i] += offset;
				}
			} else if (is_signed) {
				for (unsigned int i = 0; i < count; i++) {
					outbuf[i] = scale * RL16S(&data16[i]);
					outbuf[i] += offset;
				}
			} else {
				for (unsigned int i = 0; i < count; i++) {
					outbuf[i] = scale * RL16(&data16[i]);
					outbuf[i] += offset;
				}
			}
			break;
		case 4:
			if (is_signed && is_bigendian) {
				for (unsigned int i = 0; i < count; i++) {
					outbuf[i] = scale * RB32S(&data32[i]);
					outbuf[i] += offset;
				}
			} else if (is_bigendian) {
				for (unsigned int i = 0; i < count; i++) {
					outbuf[i] = scale * RB32(&data32[i]);
					outbuf[i] += offset;
				}
			} else if (is_signed) {
				for (unsigned int i = 0; i < count; i++) {
					outbuf[i] = scale * RL32S(&data32[i]);
					outbuf[i] += offset;
				}
			} else {
				for (unsigned int i = 0; i < count; i++) {
					outbuf[i] = scale * RL32(&data32[i]);
					outbuf[i] += offset;
				}
			}
			break;
		default:
			sr_err("Unsupported unit size '%d' for analog-to-float conversion.",
				analog->encoding->unitsize);
			return SR_ERR;
		}
		return SR_OK;
	}

	if (analog->encoding->unitsize == sizeof(float)
			&& analog->encoding->is_bigendian == bigendian
			&& analog->encoding->scale.p == 1
			&& analog->encoding->scale.q == 1
			&& analog->encoding->offset.p / (float)analog->encoding->offset.q == 0) {
		/* The data is already in the right format. */
		memcpy(outbuf, analog->data, count * sizeof(float));
	} else {
		for (i = 0; i < count; i += analog->encoding->unitsize) {
			for (b = 0; b < analog->encoding->unitsize; b++) {
				if (analog->encoding->is_bigendian == bigendian)
					((uint8_t *)outbuf)[i + b] =
						((uint8_t *)analog->data)[i * analog->encoding->unitsize + b];
				else
					((uint8_t *)outbuf)[i + (analog->encoding->unitsize - b)] =
						((uint8_t *)analog->data)[i * analog->encoding->unitsize + b];
			}
			if (analog->encoding->scale.p != 1
					|| analog->encoding->scale.q != 1)
				outbuf[i] = (outbuf[i] * analog->encoding->scale.p) / analog->encoding->scale.q;
			offset = ((float)analog->encoding->offset.p / (float)analog->encoding->offset.q);
			outbuf[i] += offset;
		}
	}

	return SR_OK;
}

/**
 * Convert the unit/MQ/MQ flags in the analog struct to a string.
 *
 * @param[in] analog Struct containing the unit, MQ and MQ flags.
 *                   Must not be NULL. analog->meaning must not be NULL.
 * @param[out] result Pointer to store result. Must not be NULL.
 *
 * The string is allocated by the function and must be freed by the caller
 * after use by calling g_free().
 *
 * @retval SR_OK Success.
 * @retval SR_ERR_ARG Invalid argument.
 *
 * @since 0.4.0
 */
SR_API int sr_analog_unit_to_string(const struct sr_datafeed_analog *analog,
		char **result)
{
	int i;
	GString *buf;

	if (!analog || !(analog->meaning) || !result)
		return SR_ERR_ARG;

	buf = g_string_new(NULL);

	for (i = 0; unit_strings[i].value; i++) {
		if (analog->meaning->unit == unit_strings[i].value) {
			g_string_assign(buf, unit_strings[i].str);
			break;
		}
	}

	/* More than one MQ flag may apply. */
	for (i = 0; mq_strings[i].value; i++)
		if (analog->meaning->mqflags & mq_strings[i].value)
			g_string_append(buf, mq_strings[i].str);

	*result = buf->str;
	g_string_free(buf, FALSE);

	return SR_OK;
}

/**
 * Set sr_rational r to the given value.
 *
 * @param[out] r Rational number struct to set. Must not be NULL.
 * @param[in] p Numerator.
 * @param[in] q Denominator.
 *
 * @since 0.4.0
 */
SR_API void sr_rational_set(struct sr_rational *r, int64_t p, uint64_t q)
{
	if (!r)
		return;

	r->p = p;
	r->q = q;
}

#ifndef HAVE___INT128_T
struct sr_int128_t {
	int64_t high;
	uint64_t low;
};

struct sr_uint128_t {
	uint64_t high;
	uint64_t low;
};

static void mult_int64(struct sr_int128_t *res, const int64_t a,
	const int64_t b)
{
	uint64_t t1, t2, t3, t4;

	t1 = (UINT32_MAX & a) * (UINT32_MAX & b);
	t2 = (UINT32_MAX & a) * (b >> 32);
	t3 = (a >> 32) * (UINT32_MAX & b);
	t4 = (a >> 32) * (b >> 32);

	res->low = t1 + (t2 << 32) + (t3 << 32);
	res->high = (t1 >> 32) + (uint64_t)((uint32_t)(t2)) + (uint64_t)((uint32_t)(t3));
	res->high >>= 32;
	res->high += ((int64_t)t2 >> 32) + ((int64_t)t3 >> 32) + t4;
}

static void mult_uint64(struct sr_uint128_t *res, const uint64_t a,
	const uint64_t b)
{
	uint64_t t1, t2, t3, t4;

	// (x1 + x2) * (y1 + y2) = x1*y1 + x1*y2 + x2*y1 + x2*y2
	t1 = (UINT32_MAX & a) * (UINT32_MAX & b);
	t2 = (UINT32_MAX & a) * (b >> 32);
	t3 = (a >> 32) * (UINT32_MAX & b);
	t4 = (a >> 32) * (b >> 32);

	res->low = t1 + (t2 << 32) + (t3 << 32);
	res->high = (t1 >> 32) + (uint64_t)((uint32_t)(t2)) + (uint64_t)((uint32_t)(t3));
	res->high >>= 32;
	res->high += ((int64_t)t2 >> 32) + ((int64_t)t3 >> 32) + t4;
}
#endif

/**
 * Compare two sr_rational for equality
 *
 * @param[in] a First value
 * @param[in] b Second value
 *
 * The values are compared for numerical equality, i.e. 2/10 == 1/5
 *
 * @retval 1 if both values are equal
 * @retval 0 otherwise
 *
 * @since 0.5.0
 */
SR_API int sr_rational_eq(const struct sr_rational *a, const struct sr_rational *b)
{
#ifdef HAVE___INT128_T
	__int128_t m1, m2;

	/* p1/q1 = p2/q2  <=>  p1*q2 = p2*q1 */
	m1 = ((__int128_t)(b->p)) * ((__uint128_t)a->q);
	m2 = ((__int128_t)(a->p)) * ((__uint128_t)b->q);

	return (m1 == m2);

#else
	struct sr_int128_t m1, m2;

	mult_int64(&m1, a->q, b->p);
	mult_int64(&m2, a->p, b->q);

	return (m1.high == m2.high) && (m1.low == m2.low);
#endif
}

/**
 * Multiply two sr_rational
 *
 * @param[in] a First value
 * @param[in] b Second value
 * @param[out] res Result
 *
 * The resulting nominator/denominator are reduced if the result would not fit
 * otherwise. If the resulting nominator/denominator are relatively prime,
 * this may not be possible.
 *
 * @retval SR_OK Success.
 * @retval SR_ERR_ARG Resulting value to large
 *
 * @since 0.5.0
 */
SR_API int sr_rational_mult(struct sr_rational *res, const struct sr_rational *a,
	const struct sr_rational *b)
{
#ifdef HAVE___INT128_T
	__int128_t p;
	__uint128_t q;

	p = (__int128_t)(a->p) * (__int128_t)(b->p);
	q = (__uint128_t)(a->q) * (__uint128_t)(b->q);

	if ((p > INT64_MAX) || (p < INT64_MIN) || (q > UINT64_MAX)) {
		while (!((p & 1) || (q & 1))) {
			p /= 2;
			q /= 2;
		}
	}

	if ((p > INT64_MAX) || (p < INT64_MIN) || (q > UINT64_MAX)) {
		// TODO: determine gcd to do further reduction
		return SR_ERR_ARG;
	}

	res->p = (int64_t)(p);
	res->q = (uint64_t)(q);

	return SR_OK;

#else
	struct sr_int128_t p;
	struct sr_uint128_t q;

	mult_int64(&p, a->p, b->p);
	mult_uint64(&q, a->q, b->q);

	while (!(p.low & 1) && !(q.low & 1)) {
		p.low /= 2;
		if (p.high & 1) p.low |= (1ll << 63);
		p.high >>= 1;
		q.low /= 2;
		if (q.high & 1) q.low |= (1ll << 63);
		q.high >>= 1;
	}

	if (q.high)
		return SR_ERR_ARG;
	if ((p.high >= 0) && (p.low > INT64_MAX))
		return SR_ERR_ARG;
	if (p.high < -1)
		return SR_ERR_ARG;

	res->p = (int64_t)p.low;
	res->q = q.low;

	return SR_OK;
#endif
}

/** @} */
Commit	Line	Data
fb019a0e BV	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2014 Bert Vermeulen <bert@biot.com>
	5	*
	6	* This program is free software: you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation, either version 3 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	18	*/
	19
6ec6c43b	20	#include <config.h>
c2a25ebb BV	21	#include <stdio.h>
c2a25ebb BV	22	#include <stdint.h>
fb019a0e	23	#include <string.h>
c2a25ebb	24	#include <ctype.h>
c1aae900	25	#include <libsigrok/libsigrok.h>
fb019a0e BV	26	#include "libsigrok-internal.h"
fb019a0e BV	27
e00b3f58	28	/** @cond PRIVATE */
fb019a0e	29	#define LOG_PREFIX "analog"
e00b3f58 UH	30	/** @endcond */
	31
	32	/**
	33	* @file
	34	*
	35	* Handling and converting analog data.
	36	*/
	37
	38	/**
	39	* @defgroup grp_analog Analog data handling
	40	*
	41	* Handling and converting analog data.
	42	*
	43	* @{
	44	*/
fb019a0e	45
a5892391 BV	46	struct unit_mq_string {
a5892391 BV	47	uint64_t value;
2c240774	48	const char *str;
a5892391 BV	49	};
a5892391 BV	50
ca7dbb56	51	/* Please use the same order as in enum sr_unit (libsigrok.h). */
a5892391 BV	52	static struct unit_mq_string unit_strings[] = {
	53	{ SR_UNIT_VOLT, "V" },
	54	{ SR_UNIT_AMPERE, "A" },
	55	{ SR_UNIT_OHM, "\xe2\x84\xa6" },
	56	{ SR_UNIT_FARAD, "F" },
a5892391 BV	57	{ SR_UNIT_KELVIN, "K" },
	58	{ SR_UNIT_CELSIUS, "\xc2\xb0""C" },
	59	{ SR_UNIT_FAHRENHEIT, "\xc2\xb0""F" },
	60	{ SR_UNIT_HERTZ, "Hz" },
	61	{ SR_UNIT_PERCENTAGE, "%" },
f7bcc686	62	{ SR_UNIT_BOOLEAN, "" },
a5892391 BV	63	{ SR_UNIT_SECOND, "s" },
	64	{ SR_UNIT_SIEMENS, "S" },
	65	{ SR_UNIT_DECIBEL_MW, "dBu" },
	66	{ SR_UNIT_DECIBEL_VOLT, "dBv" },
f7bcc686	67	{ SR_UNIT_UNITLESS, "" },
a5892391 BV	68	{ SR_UNIT_DECIBEL_SPL, "dB" },
	69	{ SR_UNIT_CONCENTRATION, "ppm" },
	70	{ SR_UNIT_REVOLUTIONS_PER_MINUTE, "RPM" },
	71	{ SR_UNIT_VOLT_AMPERE, "VA" },
	72	{ SR_UNIT_WATT, "W" },
	73	{ SR_UNIT_WATT_HOUR, "Wh" },
	74	{ SR_UNIT_METER_SECOND, "m/s" },
	75	{ SR_UNIT_HECTOPASCAL, "hPa" },
	76	{ SR_UNIT_HUMIDITY_293K, "%rF" },
	77	{ SR_UNIT_DEGREE, "\xc2\xb0" },
f7bcc686 UH	78	{ SR_UNIT_HENRY, "H" },
	79	{ SR_UNIT_GRAM, "g" },
	80	{ SR_UNIT_CARAT, "ct" },
	81	{ SR_UNIT_OUNCE, "oz" },
	82	{ SR_UNIT_TROY_OUNCE, "oz t" },
	83	{ SR_UNIT_POUND, "lb" },
	84	{ SR_UNIT_PENNYWEIGHT, "dwt" },
	85	{ SR_UNIT_GRAIN, "gr" },
	86	{ SR_UNIT_TAEL, "tael" },
	87	{ SR_UNIT_MOMME, "momme" },
	88	{ SR_UNIT_TOLA, "tola" },
	89	{ SR_UNIT_PIECE, "pcs" },
a5892391 BV	90	ALL_ZERO
	91	};
	92
ca7dbb56	93	/* Please use the same order as in enum sr_mqflag (libsigrok.h). */
a5892391	94	static struct unit_mq_string mq_strings[] = {
a5892391 BV	95	{ SR_MQFLAG_AC, " AC" },
	96	{ SR_MQFLAG_DC, " DC" },
	97	{ SR_MQFLAG_RMS, " RMS" },
	98	{ SR_MQFLAG_DIODE, " DIODE" },
	99	{ SR_MQFLAG_HOLD, " HOLD" },
	100	{ SR_MQFLAG_MAX, " MAX" },
	101	{ SR_MQFLAG_MIN, " MIN" },
	102	{ SR_MQFLAG_AUTORANGE, " AUTO" },
	103	{ SR_MQFLAG_RELATIVE, " REL" },
f7bcc686 UH	104	{ SR_MQFLAG_SPL_FREQ_WEIGHT_A, "(A)" },
	105	{ SR_MQFLAG_SPL_FREQ_WEIGHT_C, "(C)" },
	106	{ SR_MQFLAG_SPL_FREQ_WEIGHT_Z, "(Z)" },
	107	{ SR_MQFLAG_SPL_FREQ_WEIGHT_FLAT, "(SPL)" },
	108	{ SR_MQFLAG_SPL_TIME_WEIGHT_S, " S" },
	109	{ SR_MQFLAG_SPL_TIME_WEIGHT_F, " F" },
	110	{ SR_MQFLAG_SPL_LAT, " LAT" },
	111	/* Not a standard function for SLMs, so this is a made-up notation. */
	112	{ SR_MQFLAG_SPL_PCT_OVER_ALARM, "%oA" },
	113	{ SR_MQFLAG_DURATION, " DURATION" },
a5892391 BV	114	{ SR_MQFLAG_AVG, " AVG" },
a5892391 BV	115	{ SR_MQFLAG_REFERENCE, " REF" },
f7bcc686	116	{ SR_MQFLAG_UNSTABLE, " UNSTABLE" },
6d5cd3bd	117	{ SR_MQFLAG_FOUR_WIRE, " 4-WIRE" },
a5892391 BV	118	ALL_ZERO
	119	};
	120
edb691fc	121	SR_PRIV int sr_analog_init(struct sr_datafeed_analog *analog,
41caa319 AJ	122	struct sr_analog_encoding *encoding,
	123	struct sr_analog_meaning *meaning,
	124	struct sr_analog_spec *spec,
	125	int digits)
	126	{
	127	memset(analog, 0, sizeof(*analog));
	128	memset(encoding, 0, sizeof(*encoding));
	129	memset(meaning, 0, sizeof(*meaning));
	130	memset(spec, 0, sizeof(*spec));
	131
	132	analog->encoding = encoding;
	133	analog->meaning = meaning;
	134	analog->spec = spec;
	135
	136	encoding->unitsize = sizeof(float);
	137	encoding->is_float = TRUE;
	138	#ifdef WORDS_BIGENDIAN
	139	encoding->is_bigendian = TRUE;
	140	#else
	141	encoding->is_bigendian = FALSE;
	142	#endif
	143	encoding->digits = digits;
	144	encoding->is_digits_decimal = TRUE;
	145	encoding->scale.p = 1;
	146	encoding->scale.q = 1;
	147	encoding->offset.p = 0;
	148	encoding->offset.q = 1;
	149
	150	spec->spec_digits = digits;
	151
	152	return SR_OK;
	153	}
	154
22fb1bff UH	155	/**
	156	* Convert an analog datafeed payload to an array of floats.
	157	*
	158	* @param[in] analog The analog payload to convert. Must not be NULL.
	159	* analog->data, analog->meaning, and analog->encoding
	160	* must not be NULL.
	161	* @param[out] outbuf Memory where to store the result. Must not be NULL.
	162	*
	163	* Sufficient memory for outbuf must have been pre-allocated by the caller,
	164	* who is also responsible for freeing it when no longer needed.
	165	*
	166	* @retval SR_OK Success.
	167	* @retval SR_ERR Unsupported encoding.
	168	* @retval SR_ERR_ARG Invalid argument.
	169	*
	170	* @since 0.4.0
	171	*/
edb691fc	172	SR_API int sr_analog_to_float(const struct sr_datafeed_analog *analog,
4b4fdeea	173	float *outbuf)
fb019a0e BV	174	{
fb019a0e BV	175	float offset;
5cee3d08	176	unsigned int b, i, count;
fb019a0e	177	gboolean bigendian;
5cee3d08 UH	178
	179	if (!analog \|\| !(analog->data) \|\| !(analog->meaning)
	180	\|\| !(analog->encoding) \|\| !outbuf)
	181	return SR_ERR_ARG;
	182
	183	count = analog->num_samples * g_slist_length(analog->meaning->channels);
fb019a0e BV	184
	185	#ifdef WORDS_BIGENDIAN
	186	bigendian = TRUE;
	187	#else
	188	bigendian = FALSE;
	189	#endif
	190	if (!analog->encoding->is_float) {
4d376e08 SB	191	float offset = analog->encoding->offset.p / (float)analog->encoding->offset.q;
	192	float scale = analog->encoding->scale.p / (float)analog->encoding->scale.q;
	193	gboolean is_signed = analog->encoding->is_signed;
	194	gboolean is_bigendian = analog->encoding->is_bigendian;
	195	int8_t data8 = (int8_t )(analog->data);
	196	int16_t data16 = (int16_t )(analog->data);
	197	int32_t data32 = (int32_t )(analog->data);
	198
	199	switch (analog->encoding->unitsize) {
	200	case 1:
	201	if (is_signed) {
	202	for (unsigned int i = 0; i < count; i++) {
	203	outbuf[i] = scale * data8[i];
	204	outbuf[i] += offset;
	205	}
	206	} else {
	207	for (unsigned int i = 0; i < count; i++) {
	208	outbuf[i] = scale * R8(data8 + i);
	209	outbuf[i] += offset;
	210	}
	211	}
	212	break;
	213	case 2:
	214	if (is_signed && is_bigendian) {
	215	for (unsigned int i = 0; i < count; i++) {
	216	outbuf[i] = scale * RB16S(&data16[i]);
	217	outbuf[i] += offset;
	218	}
	219	} else if (is_bigendian) {
	220	for (unsigned int i = 0; i < count; i++) {
	221	outbuf[i] = scale * RB16(&data16[i]);
	222	outbuf[i] += offset;
	223	}
	224	} else if (is_signed) {
	225	for (unsigned int i = 0; i < count; i++) {
	226	outbuf[i] = scale * RL16S(&data16[i]);
	227	outbuf[i] += offset;
	228	}
	229	} else {
	230	for (unsigned int i = 0; i < count; i++) {
	231	outbuf[i] = scale * RL16(&data16[i]);
	232	outbuf[i] += offset;
	233	}
	234	}
	235	break;
	236	case 4:
	237	if (is_signed && is_bigendian) {
	238	for (unsigned int i = 0; i < count; i++) {
	239	outbuf[i] = scale * RB32S(&data32[i]);
	240	outbuf[i] += offset;
	241	}
	242	} else if (is_bigendian) {
	243	for (unsigned int i = 0; i < count; i++) {
	244	outbuf[i] = scale * RB32(&data32[i]);
	245	outbuf[i] += offset;
	246	}
	247	} else if (is_signed) {
	248	for (unsigned int i = 0; i < count; i++) {
	249	outbuf[i] = scale * RL32S(&data32[i]);
	250	outbuf[i] += offset;
	251	}
	252	} else {
	253	for (unsigned int i = 0; i < count; i++) {
	254	outbuf[i] = scale * RL32(&data32[i]);
255	outbuf[i] += offset;
256	}
257	}
258	break;
259	default:
260	sr_err("Unsupported unit size '%d' for analog-to-float conversion.",
261	analog->encoding->unitsize);
262	return SR_ERR;
263	}
264	return SR_OK;
fb019a0e BV	265	}
	266
	267	if (analog->encoding->unitsize == sizeof(float)
	268	&& analog->encoding->is_bigendian == bigendian
b07a1b04 ML	269	&& analog->encoding->scale.p == 1
b07a1b04 ML	270	&& analog->encoding->scale.q == 1
4b4fdeea	271	&& analog->encoding->offset.p / (float)analog->encoding->offset.q == 0) {
fb019a0e	272	/* The data is already in the right format. */
7d65dd3a	273	memcpy(outbuf, analog->data, count * sizeof(float));
fb019a0e	274	} else {
7d65dd3a	275	for (i = 0; i < count; i += analog->encoding->unitsize) {
fb019a0e BV	276	for (b = 0; b < analog->encoding->unitsize; b++) {
fb019a0e BV	277	if (analog->encoding->is_bigendian == bigendian)
3e277549 ML	278	((uint8_t *)outbuf)[i + b] =
3e277549 ML	279	((uint8_t )analog->data)[i analog->encoding->unitsize + b];
fb019a0e	280	else
3e277549 ML	281	((uint8_t *)outbuf)[i + (analog->encoding->unitsize - b)] =
3e277549 ML	282	((uint8_t )analog->data)[i analog->encoding->unitsize + b];
fb019a0e	283	}
b07a1b04 ML	284	if (analog->encoding->scale.p != 1
b07a1b04 ML	285	\|\| analog->encoding->scale.q != 1)
4b4fdeea BV	286	outbuf[i] = (outbuf[i] * analog->encoding->scale.p) / analog->encoding->scale.q;
	287	offset = ((float)analog->encoding->offset.p / (float)analog->encoding->offset.q);
	288	outbuf[i] += offset;
fb019a0e BV	289	}
	290	}
	291
	292	return SR_OK;
	293	}
c2a25ebb	294
22fb1bff	295	/**
a5892391 BV	296	* Convert the unit/MQ/MQ flags in the analog struct to a string.
a5892391 BV	297	*
22fb1bff UH	298	* @param[in] analog Struct containing the unit, MQ and MQ flags.
	299	* Must not be NULL. analog->meaning must not be NULL.
	300	* @param[out] result Pointer to store result. Must not be NULL.
a24da9a8 ML	301	*
	302	* The string is allocated by the function and must be freed by the caller
	303	* after use by calling g_free().
a5892391	304	*
22fb1bff UH	305	* @retval SR_OK Success.
22fb1bff UH	306	* @retval SR_ERR_ARG Invalid argument.
a5892391 BV	307	*
	308	* @since 0.4.0
	309	*/
edb691fc	310	SR_API int sr_analog_unit_to_string(const struct sr_datafeed_analog *analog,
a24da9a8	311	char **result)
a5892391	312	{
a24da9a8	313	int i;
5cee3d08 UH	314	GString *buf;
	315
	316	if (!analog \|\| !(analog->meaning) \|\| !result)
	317	return SR_ERR_ARG;
	318
	319	buf = g_string_new(NULL);
a5892391	320
a5892391 BV	321	for (i = 0; unit_strings[i].value; i++) {
a5892391 BV	322	if (analog->meaning->unit == unit_strings[i].value) {
a24da9a8	323	g_string_assign(buf, unit_strings[i].str);
a5892391 BV	324	break;
	325	}
	326	}
	327
	328	/* More than one MQ flag may apply. */
a24da9a8 ML	329	for (i = 0; mq_strings[i].value; i++)
	330	if (analog->meaning->mqflags & mq_strings[i].value)
	331	g_string_append(buf, mq_strings[i].str);
	332
	333	*result = buf->str;
	334	g_string_free(buf, FALSE);
a5892391 BV	335
	336	return SR_OK;
	337	}
	338
22fb1bff	339	/**
90cefe0c BV	340	* Set sr_rational r to the given value.
90cefe0c BV	341	*
22fb1bff UH	342	* @param[out] r Rational number struct to set. Must not be NULL.
	343	* @param[in] p Numerator.
	344	* @param[in] q Denominator.
	345	*
	346	* @since 0.4.0
90cefe0c	347	*/
53e5d3d1	348	SR_API void sr_rational_set(struct sr_rational *r, int64_t p, uint64_t q)
90cefe0c	349	{
5cee3d08 UH	350	if (!r)
	351	return;
	352
90cefe0c BV	353	r->p = p;
	354	r->q = q;
	355	}
	356
bdba3626 SB	357	#ifndef HAVE___INT128_T
	358	struct sr_int128_t {
	359	int64_t high;
	360	uint64_t low;
	361	};
	362
	363	struct sr_uint128_t {
	364	uint64_t high;
	365	uint64_t low;
	366	};
	367
	368	static void mult_int64(struct sr_int128_t *res, const int64_t a,
	369	const int64_t b)
	370	{
	371	uint64_t t1, t2, t3, t4;
	372
	373	t1 = (UINT32_MAX & a) * (UINT32_MAX & b);
	374	t2 = (UINT32_MAX & a) * (b >> 32);
	375	t3 = (a >> 32) * (UINT32_MAX & b);
	376	t4 = (a >> 32) * (b >> 32);
	377
	378	res->low = t1 + (t2 << 32) + (t3 << 32);
	379	res->high = (t1 >> 32) + (uint64_t)((uint32_t)(t2)) + (uint64_t)((uint32_t)(t3));
	380	res->high >>= 32;
	381	res->high += ((int64_t)t2 >> 32) + ((int64_t)t3 >> 32) + t4;
	382	}
	383
	384	static void mult_uint64(struct sr_uint128_t *res, const uint64_t a,
	385	const uint64_t b)
	386	{
	387	uint64_t t1, t2, t3, t4;
	388
	389	// (x1 + x2) * (y1 + y2) = x1y1 + x1y2 + x2y1 + x2y2
	390	t1 = (UINT32_MAX & a) * (UINT32_MAX & b);
	391	t2 = (UINT32_MAX & a) * (b >> 32);
	392	t3 = (a >> 32) * (UINT32_MAX & b);
	393	t4 = (a >> 32) * (b >> 32);
	394
	395	res->low = t1 + (t2 << 32) + (t3 << 32);
	396	res->high = (t1 >> 32) + (uint64_t)((uint32_t)(t2)) + (uint64_t)((uint32_t)(t3));
	397	res->high >>= 32;
	398	res->high += ((int64_t)t2 >> 32) + ((int64_t)t3 >> 32) + t4;
	399	}
	400	#endif
	401
	402	/**
	403	* Compare two sr_rational for equality
	404	*
	405	* @param[in] a First value
	406	* @param[in] b Second value
	407	*
	408	* The values are compared for numerical equality, i.e. 2/10 == 1/5
	409	*
	410	* @retval 1 if both values are equal
	411	* @retval 0 otherwise
	412	*
	413	* @since 0.5.0
	414	*/
	415	SR_API int sr_rational_eq(const struct sr_rational a, const struct sr_rational b)
	416	{
	417	#ifdef HAVE___INT128_T
	418	__int128_t m1, m2;
	419
	420	/* p1/q1 = p2/q2 <=> p1q2 = p2q1 */
421	m1 = ((__int128_t)(b->p)) * ((__uint128_t)a->q);
422	m2 = ((__int128_t)(a->p)) * ((__uint128_t)b->q);
423
424	return (m1 == m2);
425
426	#else
427	struct sr_int128_t m1, m2;
428
429	mult_int64(&m1, a->q, b->p);
430	mult_int64(&m2, a->p, b->q);
431
432	return (m1.high == m2.high) && (m1.low == m2.low);
433	#endif
434	}
435
ee1b6054 SB	436	/**
	437	* Multiply two sr_rational
	438	*
	439	* @param[in] a First value
	440	* @param[in] b Second value
	441	* @param[out] res Result
	442	*
	443	* The resulting nominator/denominator are reduced if the result would not fit
	444	* otherwise. If the resulting nominator/denominator are relatively prime,
	445	* this may not be possible.
	446	*
	447	* @retval SR_OK Success.
	448	* @retval SR_ERR_ARG Resulting value to large
	449	*
	450	* @since 0.5.0
	451	*/
	452	SR_API int sr_rational_mult(struct sr_rational res, const struct sr_rational a,
	453	const struct sr_rational *b)
	454	{
	455	#ifdef HAVE___INT128_T
	456	__int128_t p;
	457	__uint128_t q;
	458
	459	p = (__int128_t)(a->p) * (__int128_t)(b->p);
	460	q = (__uint128_t)(a->q) * (__uint128_t)(b->q);
	461
	462	if ((p > INT64_MAX) \|\| (p < INT64_MIN) \|\| (q > UINT64_MAX)) {
	463	while (!((p & 1) \|\| (q & 1))) {
	464	p /= 2;
	465	q /= 2;
	466	}
	467	}
	468
	469	if ((p > INT64_MAX) \|\| (p < INT64_MIN) \|\| (q > UINT64_MAX)) {
	470	// TODO: determine gcd to do further reduction
	471	return SR_ERR_ARG;
	472	}
	473
	474	res->p = (int64_t)(p);
	475	res->q = (uint64_t)(q);
	476
	477	return SR_OK;
	478
	479	#else
	480	struct sr_int128_t p;
	481	struct sr_uint128_t q;
	482
	483	mult_int64(&p, a->p, b->p);
	484	mult_uint64(&q, a->q, b->q);
	485
	486	while (!(p.low & 1) && !(q.low & 1)) {
	487	p.low /= 2;
	488	if (p.high & 1) p.low \|= (1ll << 63);
	489	p.high >>= 1;
	490	q.low /= 2;
	491	if (q.high & 1) q.low \|= (1ll << 63);
	492	q.high >>= 1;
	493	}
	494
	495	if (q.high)
	496	return SR_ERR_ARG;
	497	if ((p.high >= 0) && (p.low > INT64_MAX))
	498	return SR_ERR_ARG;
	499	if (p.high < -1)
500	return SR_ERR_ARG;
501
502	res->p = (int64_t)p.low;
503	res->q = q.low;
504
505	return SR_OK;
506	#endif
507	}
508
e00b3f58	509	/** @} */