ref: a13347033a4fb16b68b4291587640855746e7412
dir: /TestPlugin/Source/Yin.h/
/*
==============================================================================
Yin.h
Created: 17 Jan 2017 1:20:23pm
Author: Michael R Mulshine
==============================================================================
*/
#ifndef YIN_H_INCLUDED
#define YIN_H_INCLUDED
#include <stdint.h>
#define YIN_SAMPLING_RATE 44100
#define YIN_DEFAULT_THRESHOLD 0.15
/**
* @struct Yin
* @breif Object to encapsulate the parameters for the Yin pitch detection algorithm
*/
typedef struct _Yin {
int16_t bufferSize; /**< Size of the audio buffer to be analysed */
int16_t halfBufferSize; /**< Half the buffer length */
float* yinBuffer; /**< Buffer that stores the results of the intermediate processing steps of the algorithm */
float probability; /**< Probability that the pitch found is correct as a decimal (i.e 0.85 is 85%) */
float threshold; /**< Allowed uncertainty in the result as a decimal (i.e 0.15 is 15%) */
} Yin;
/**
* Initialise the Yin pitch detection object
* @param yin Yin pitch detection object to initialise
* @param bufferSize Length of the audio buffer to analyse
* @param threshold Allowed uncertainty (e.g 0.05 will return a pitch with ~95% probability)
*/
void Yin_init(Yin *yin, int16_t bufferSize, float threshold);
/**
* Runs the Yin pitch detection algortihm
* @param yin Initialised Yin object
* @param buffer Buffer of samples to analyse
* @return Fundamental frequency of the signal in Hz. Returns -1 if pitch can't be found
*/
float Yin_getPitch(Yin *yin, int16_t* buffer);
/**
* Certainty of the pitch found
* @param yin Yin object that has been run over a buffer
* @return Returns the certainty of the note found as a decimal (i.e 0.3 is 30%)
*/
float Yin_getProbability(Yin *yin);
#endif // YIN_H_INCLUDED