PitchDetector

java.lang.Object
- ptolemy.actor.lib.javasound.test.pitchshift.PitchDetector

```
public class PitchDetector
extends java.lang.Object
```
Perform pitch detection on an input signal using an autocorrelation estimate. The autocorrelation estimate is computed using the DFT (an FFT algorithm is used) for efficiency.

Since:

Ptolemy II 1.0

Version:

$Id$

Author:

Brian K. Vogel

Pt.AcceptedRating:

Red (vogel)

Pt.ProposedRating:

Red (vogel)

- Constructor Summary
  
  Constructors
  Constructor Description
  
  PitchDetector(int vectorSize, int sampleRate)
  Initialize the pitch detector.
- Method Summary
  
  All Methods Instance Methods Concrete Methods
  Modifier and Type Method Description
  
  double[] performPitchDetect(double[] inputArray)
  Perform pitch detection.
  - Methods inherited from class java.lang.Object
    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - PitchDetector
```
public PitchDetector(int vectorSize,
                     int sampleRate)
```
    Initialize the pitch detector. Parameter vectorSize sets the vector size to be used by performPitchDetect(). vectorSize may be any length.
    
    Parameters:
    
    vectorSize - The length of the array parameter to performPitchDetect().
    
    sampleRate - The sample rate to use, in Hz. 22050 or 44100 is recomended.
- Method Detail
  - performPitchDetect
```
public double[] performPitchDetect(double[] inputArray)
```
    Perform pitch detection. The input signal should uniformly partitioned into vectorSize length chunks of data. performPitchDetect() should be called on each consecutive vector of input data. A vectorSize length array of doubles containing the data is passed to performPitchDetect() via inputArray[]. Each element of inputArray[] is assumes to contain a single data sample. The _sampleRate parameter contains that sample rate, in Hz. performPitchDetect() returns a vectorSize length array of doubles containing the pitch estimates.
    Note that there is a 2048 sample delay between an element of inputArray[] and the corresponding element of the returned vector of pitch estimates.
    
    Parameters:
    
    inputArray - The array of audio sample to process.
    
    Returns:
    
    An array of pitch estimates of the same length as the input array parameter.