X-Git-Url: https://sigrok.org/gitweb/?p=libsigrok.git;a=blobdiff_plain;f=src%2Fconversion.c;fp=src%2Fconversion.c;h=3d969308c4b4b15a3a00476ee9adbf67c02c4003;hp=0000000000000000000000000000000000000000;hb=8cd15dd4ce2fdbefbcc6e64632c8006e5404f253;hpb=1aba65727015e298f213c851dbc8d2d57d27d37b

diff --git a/src/conversion.c b/src/conversion.c
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+++ b/src/conversion.c
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+/*
+ * This file is part of the libsigrok project.
+ *
+ * Copyright (C) 2017 Soeren Apel <soeren@apelpie.net>
+ *
+ * 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 2 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/>.
+ */
+
+/**
+ * @file
+ *
+ * Conversion helper functions.
+ */
+
+#include <libsigrok/libsigrok.h>
+#include "libsigrok-internal.h"
+
+#define LOG_PREFIX "conv"
+
+/**
+ * Convert analog values to logic values by using a fixed threshold.
+ *
+ * @param[in] analog The analog input values.
+ * @param[in] threshold The threshold to use.
+ * @param[out] output The converted output values; either 0 or 1. Must provide
+ *                    space for count bytes.
+ * @param[in] count The number of samples to process.
+ *
+ * @return SR_OK on success or SR_ERR on failure.
+ */
+SR_API int sr_a2l_threshold(const struct sr_datafeed_analog *analog,
+		float threshold, uint8_t *output, uint64_t count)
+{
+	float *input;
+
+	if (!analog->encoding->is_float) {
+		input = g_try_malloc(sizeof(float) * count);
+		if (!input)
+			return SR_ERR;
+
+		sr_analog_to_float(analog, input);
+	} else
+		input = analog->data;
+
+	for (uint64_t i = 0; i < count; i++)
+		output[i] = (input[i] >= threshold) ? 1 : 0;
+
+	if (!analog->encoding->is_float)
+		g_free(input);
+
+	return SR_OK;
+}
+
+/**
+ * Convert analog values to logic values by using a Schmitt-trigger algorithm.
+ *
+ * @param analog The analog input values.
+ * @param lo_thr The low threshold - result becomes 0 below it.
+ * @param lo_thr The high threshold - result becomes 1 above it.
+ * @param state The internal converter state. Must contain the state of logic
+ *        sample n-1, will contain the state of logic sample n+count upon exit.
+ * @param output The converted output values; either 0 or 1. Must provide
+ *        space for count bytes.
+ * @param count The number of samples to process.
+ *
+ * @return SR_OK on success or SR_ERR on failure.
+ */
+SR_API int sr_a2l_schmitt_trigger(const struct sr_datafeed_analog *analog,
+		float lo_thr, float hi_thr, uint8_t *state, uint8_t *output,
+		uint64_t count)
+{
+	float *input;
+
+	if (!analog->encoding->is_float) {
+		input = g_try_malloc(sizeof(float) * count);
+		if (!input)
+			return SR_ERR;
+
+		sr_analog_to_float(analog, input);
+	} else
+		input = analog->data;
+
+	for (uint64_t i = 0; i < count; i++) {
+		if (input[i] < lo_thr)
+			*state = 0;
+		else if (input[i] > hi_thr)
+			*state = 1;
+
+		output[i] = *state;
+	}
+
+	if (!analog->encoding->is_float)
+		g_free(input);
+
+	return SR_OK;
+}