1 files changed, 27 insertions, 0 deletions
diff --git a/xtract/xtract_scalar.h b/xtract/xtract_scalar.h
index 4461623..8e24284 100644
--- a/xtract/xtract_scalar.h
+++ b/xtract/xtract_scalar.h
@@ -434,6 +434,19 @@ int xtract_failsafe_f0(const double *data, const int N, const void *argv, double
  */
 int xtract_wavelet_f0(const double *data, const int N, const void *argv, double *result);
 
+    
+/** \brief Convenience function to convert a frequency in Hertz to a "pitch" value in MIDI cents
+ *
+ * \param *data: not used
+ * \param N: not used
+ * \param *argv: a pointer to a double-precision floating point value representing a frequency in Hertz
+ * \param *result: a pointer to a double-precision floating point value representing a "pitch" in MIDI cents
+ * \return if *argv value causes a *result within the range 0..127, XTRACT_SUCCESS will be returned, otherwise XTRACT_ARGUMENT_ERROR
+ *
+ */
+int xtract_midicent(const double *data, const int N, const void *argv, double *result);
+
+    
 /** \brief Extract the number of non-zero elements in an input vector
  * 
  * \param *data: a pointer to the first element in an array of doubles
@@ -444,6 +457,20 @@ int xtract_wavelet_f0(const double *data, const int N, const void *argv, double
  */
 int xtract_nonzero_count(const double *data, const int N, const void *argv, double *result);
 
+/**
+ *  \brief Return XTRACT_SUCCESS if the 'current' value is considered a peak
+ *
+ *  @param data   a pointer to an array containing time series as provided by *result from xtract_last_n() where the Nth value is considered the 'current' value
+ *  @param N      an integer representing the number of elements in the time series
+ *  @param argv   a pointer to a double representing the threshold, whereby the current value will be considered a peak if it is above the average of the last N values (*data) by the threshold
+ *  @param result a pointer to a copy of the current value if the current value is considered a peak
+ *
+ *
+ *  @return XTRACT_SUCCESS if a peak was found or XTRACT_NO_RESULT if not
+ */
+int xtract_peak(const double *data, const int N, const void *argv, double *result);
+
+    
 /** @} */
 
 #ifdef __cplusplus