]> sigrok.org Git - libsigrok.git/blobdiff - src/analog.c
Doxyfile: Set version to 0.4.0.
[libsigrok.git] / src / analog.c
index db5ac1cf8315476ae3f9c60fc8b1c768897728f3..892cc6ec15fe144229742bf1fc31ec786e7cbe59 100644 (file)
@@ -45,7 +45,7 @@
 
 struct unit_mq_string {
        uint64_t value;
-       char *str;
+       const char *str;
 };
 
 /* Please use the same order as in enum sr_unit (libsigrok.h). */
@@ -117,7 +117,7 @@ static struct unit_mq_string mq_strings[] = {
        ALL_ZERO
 };
 
-SR_PRIV int sr_analog_init(struct sr_datafeed_analog2 *analog,
+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,
@@ -151,14 +151,35 @@ SR_PRIV int sr_analog_init(struct sr_datafeed_analog2 *analog,
        return SR_OK;
 }
 
-SR_API int sr_analog_to_float(const struct sr_datafeed_analog2 *analog,
+/**
+ * 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;
+       unsigned int b, i, count;
        gboolean bigendian;
-       unsigned int count = (analog->num_samples
-                       * g_slist_length(analog->meaning->channels));
+
+       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;
@@ -166,14 +187,86 @@ SR_API int sr_analog_to_float(const struct sr_datafeed_analog2 *analog,
        bigendian = FALSE;
 #endif
        if (!analog->encoding->is_float) {
-               /* TODO */
-               sr_err("Only floating-point encoding supported so far.");
-               return SR_ERR;
+               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 == analog->encoding->scale.q)
+                       && 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));
@@ -187,7 +280,8 @@ SR_API int sr_analog_to_float(const struct sr_datafeed_analog2 *analog,
                                        ((uint8_t *)outbuf)[i + (analog->encoding->unitsize - b)] =
                                                ((uint8_t *)analog->data)[i * analog->encoding->unitsize + b];
                        }
-                       if (analog->encoding->scale.p != analog->encoding->scale.q)
+                       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;
@@ -197,57 +291,31 @@ SR_API int sr_analog_to_float(const struct sr_datafeed_analog2 *analog,
        return SR_OK;
 }
 
-/*
- * Convert a floating point value to a string, limited to the given
- * number of decimal digits.
- *
- * @param value The value to convert.
- * @param digits Number of digits after the decimal point to print.
- * @param result Pointer to store result.
- *
- * The string is allocated by the function and must be freed by the caller
- * after use by calling g_free().
- *
- * @retval SR_OK
- *
- * @since 0.4.0
- */
-SR_API int sr_analog_float_to_string(float value, int digits, char **result)
-{
-       int cnt, i;
-
-       /* This produces at least one too many digits */
-       *result = g_strdup_printf("%.*f", digits, value);
-       for (i = 0, cnt = 0; (*result)[i]; i++) {
-               if (isdigit((*result)[i++]))
-                       cnt++;
-               if (cnt == digits) {
-                       (*result)[i] = 0;
-                       break;
-               }
-       }
-
-       return SR_OK;
-}
-
-/*
+/**
  * Convert the unit/MQ/MQ flags in the analog struct to a string.
  *
- * @param analog Struct containing the unit, MQ and MQ flags.
- * @param result Pointer to store result.
+ * @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
+ * @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_analog2 *analog,
+SR_API int sr_analog_unit_to_string(const struct sr_datafeed_analog *analog,
                char **result)
 {
        int i;
-       GString *buf = g_string_new(NULL);
+       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) {
@@ -267,14 +335,20 @@ SR_API int sr_analog_unit_to_string(const struct sr_datafeed_analog2 *analog,
        return SR_OK;
 }
 
-/*
+/**
  * Set sr_rational r to the given value.
  *
- * @param p Numerator
- * @param q Denominator
+ * @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;
 }