/* * This file is part of the libsigrok project. * * Copyright (C) 2014 Bert Vermeulen * * 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 . */ #include #include #include #include #include #include #include #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, "dBm" }, { 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" }, { SR_UNIT_JOULE, "J" }, { SR_UNIT_COULOMB, "C" }, { SR_UNIT_AMPERE_HOUR, "Ah" }, 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 }; /** @private */ 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. * * The caller must provide the #outbuf space for the conversion result, * and is expected to free allocated space after use. * * @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. * * @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) { size_t count; gboolean host_bigendian; gboolean input_float, input_signed, input_bigendian; size_t input_unitsize; double scale, offset, value; const uint8_t *data8; gboolean input_is_native; char type_text[10]; if (!analog || !analog->data || !analog->meaning || !analog->encoding) return SR_ERR_ARG; if (!outbuf) return SR_ERR_ARG; count = analog->num_samples * g_slist_length(analog->meaning->channels); /* * Determine properties of the input data's and the host's * native formats, to simplify test conditions below. * Error messages for unsupported input property combinations * will only be seen by developers and maintainers of input * formats or acquisition device drivers. Terse output is * acceptable there, users shall never see them. */ #ifdef WORDS_BIGENDIAN host_bigendian = TRUE; #else host_bigendian = FALSE; #endif input_float = analog->encoding->is_float; input_signed = analog->encoding->is_signed; input_bigendian = analog->encoding->is_bigendian; input_unitsize = analog->encoding->unitsize; /* * Prepare the iteration over the sample data: Get the common * scale/offset factors which apply to all individual values. * Position the read pointer on the first byte of input data. */ offset = analog->encoding->offset.p; offset /= analog->encoding->offset.q; scale = analog->encoding->scale.p; scale /= analog->encoding->scale.q; data8 = analog->data; /* * Immediately handle the special case where input data needs * no conversion because it already is in the application's * native format. Do apply scale/offset though when applicable * on our way out. */ input_is_native = input_float && input_unitsize == sizeof(outbuf[0]) && input_bigendian == host_bigendian; if (input_is_native) { memcpy(outbuf, data8, count * sizeof(outbuf[0])); if (scale != 1.0 || offset != 0.0) { while (count--) { *outbuf *= scale; *outbuf += offset; outbuf++; } } return SR_OK; } /* * Accept sample values in different widths and data types and * endianess formats (floating point or signed or unsigned * integer, in either endianess, for a set of supported widths). * Common scale/offset factors apply to all sample values. * * Do most internal calculations on double precision values. * Only trim the result data to single precision, since that's * the routine's result data type in its public API which needs * to be kept for compatibility. It remains an option for later * to add another public routine which returns double precision * result data, call sites could migrate at their own pace. */ if (input_float && input_unitsize == sizeof(float)) { float (*reader)(const uint8_t **p); if (input_bigendian) reader = read_fltbe_inc; else reader = read_fltle_inc; while (count--) { value = reader(&data8); value *= scale; value += offset; *outbuf++ = value; } return SR_OK; } if (input_float && input_unitsize == sizeof(double)) { double (*reader)(const uint8_t **p); if (input_bigendian) reader = read_dblbe_inc; else reader = read_dblle_inc; while (count--) { value = reader(&data8); value *= scale; value += offset; *outbuf++ = value; } return SR_OK; } if (input_float) { snprintf(type_text, sizeof(type_text), "%c%zu%s", 'f', input_unitsize * 8, input_bigendian ? "be" : "le"); sr_err("Unsupported type for analog-to-float conversion: %s.", type_text); return SR_ERR; } if (input_unitsize == sizeof(uint8_t) && input_signed) { int8_t (*reader)(const uint8_t **p); reader = read_i8_inc; while (count--) { value = reader(&data8); value *= scale; value += offset; *outbuf++ = value; } return SR_OK; } if (input_unitsize == sizeof(uint8_t)) { uint8_t (*reader)(const uint8_t **p); reader = read_u8_inc; while (count--) { value = reader(&data8); value *= scale; value += offset; *outbuf++ = value; } return SR_OK; } if (input_unitsize == sizeof(uint16_t) && input_signed) { int16_t (*reader)(const uint8_t **p); if (input_bigendian) reader = read_i16be_inc; else reader = read_i16le_inc; while (count--) { value = reader(&data8); value *= scale; value += offset; *outbuf++ = value; } return SR_OK; } if (input_unitsize == sizeof(uint16_t)) { uint16_t (*reader)(const uint8_t **p); if (input_bigendian) reader = read_u16be_inc; else reader = read_u16le_inc; while (count--) { value = reader(&data8); value *= scale; value += offset; *outbuf++ = value; } return SR_OK; } if (input_unitsize == sizeof(uint32_t) && input_signed) { int32_t (*reader)(const uint8_t **p); if (input_bigendian) reader = read_i32be_inc; else reader = read_i32le_inc; while (count--) { value = reader(&data8); value *= scale; value += offset; *outbuf++ = value; } return SR_OK; } if (input_unitsize == sizeof(uint32_t)) { uint32_t (*reader)(const uint8_t **p); if (input_bigendian) reader = read_u32be_inc; else reader = read_u32le_inc; while (count--) { value = reader(&data8); value *= scale; value += offset; *outbuf++ = value; } return SR_OK; } snprintf(type_text, sizeof(type_text), "%c%zu%s", input_float ? 'f' : input_signed ? 'i' : 'u', input_unitsize * 8, input_bigendian ? "be" : "le"); sr_err("Unsupported type for analog-to-float conversion: %s.", type_text); return SR_ERR; } /** * Scale a float value to the appropriate SI prefix. * * @param[in,out] value The float value to convert to appropriate SI prefix. * @param[in,out] digits The number of significant decimal digits in value. * * @return The SI prefix to which value was scaled, as a printable string. * * @since 0.5.0 */ SR_API const char *sr_analog_si_prefix(float *value, int *digits) { /** @cond PRIVATE */ #define NEG_PREFIX_COUNT 5 /* number of prefixes below unity */ #define POS_PREFIX_COUNT (int)(ARRAY_SIZE(prefixes) - NEG_PREFIX_COUNT - 1) /** @endcond */ static const char *prefixes[] = { "f", "p", "n", "ยต", "m", "", "k", "M", "G", "T" }; if (!value || !digits || isnan(*value)) return prefixes[NEG_PREFIX_COUNT]; float logval = log10f(fabsf(*value)); int prefix = (logval / 3) - (logval < 1); if (prefix < -NEG_PREFIX_COUNT) prefix = -NEG_PREFIX_COUNT; if (3 * prefix < -*digits) prefix = (-*digits + 2 * (*digits < 0)) / 3; if (prefix > POS_PREFIX_COUNT) prefix = POS_PREFIX_COUNT; *value *= powf(10, -3 * prefix); *digits += 3 * prefix; return prefixes[prefix + NEG_PREFIX_COUNT]; } /** * Check if a unit "accepts" an SI prefix. * * E.g. SR_UNIT_VOLT is SI prefix friendly while SR_UNIT_DECIBEL_MW or * SR_UNIT_PERCENTAGE are not. * * @param[in] unit The unit to check for SI prefix "friendliness". * * @return TRUE if the unit "accept" an SI prefix. * * @since 0.5.0 */ SR_API gboolean sr_analog_si_prefix_friendly(enum sr_unit unit) { static const enum sr_unit prefix_friendly_units[] = { SR_UNIT_VOLT, SR_UNIT_AMPERE, SR_UNIT_OHM, SR_UNIT_FARAD, SR_UNIT_KELVIN, SR_UNIT_HERTZ, SR_UNIT_SECOND, SR_UNIT_SIEMENS, SR_UNIT_VOLT_AMPERE, SR_UNIT_WATT, SR_UNIT_WATT_HOUR, SR_UNIT_METER_SECOND, SR_UNIT_HENRY, SR_UNIT_GRAM }; unsigned int i; for (i = 0; i < ARRAY_SIZE(prefix_friendly_units); i++) if (unit == prefix_friendly_units[i]) return TRUE; return FALSE; } /** * Convert the unit/MQ/MQ flags in the analog struct to a string. * * The string is allocated by the function and must be freed by the caller * after use by calling g_free(). * * @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. * * @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. * * The values are compared for numerical equality, i.e. 2/10 == 1/5. * * @param[in] a First value. * @param[in] b Second value. * * @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. * * 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. * * It is safe to use the same variable for result and input values. * * @param[in] a First value. * @param[in] b Second value. * @param[out] res Result. * * @retval SR_OK Success. * @retval SR_ERR_ARG Resulting value too 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 } /** * Divide rational a by rational b. * * 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. * * It is safe to use the same variable for result and input values. * * @param[in] num Numerator. * @param[in] div Divisor. * @param[out] res Result. * * @retval SR_OK Success. * @retval SR_ERR_ARG Division by zero, denominator of divisor too large, * or resulting value too large. * * @since 0.5.0 */ SR_API int sr_rational_div(struct sr_rational *res, const struct sr_rational *num, const struct sr_rational *div) { struct sr_rational t; if (div->q > INT64_MAX) return SR_ERR_ARG; if (div->p == 0) return SR_ERR_ARG; if (div->p > 0) { t.p = div->q; t.q = div->p; } else { t.p = -div->q; t.q = -div->p; } return sr_rational_mult(res, num, &t); } /** @} */