SpectrumExtr Class Reference

Retrives the spectrum using FFT. More...

#include <spectrum.h>

Inheritance diagram for SpectrumExtr:

List of all members.

Public Types
enum	FTWindow { WINDOW_RECTANGULAR, WINDOW_TRIANGULAR, WINDOW_HAMMING, WINDOW_BH }
typedef enum FTWindow	FTWindow

Public Member Functions
	SpectrumExtr (int chunkSize=0)
	Memory management.
void	reallocate ()
	Reallocate buffers based on the new size (plus butterfly computation)
	~SpectrumExtr ()
	Cleans everything up.
bool	extract (std::deque< uint16_t > data, int size)
	Algorithm.
void	normalize (int bound)
	Normalize the values (so that the values go from 0 to bound)
float	value (int index)
	Accessors.
uint16_t *	spectrum ()
	Retrieve the entire array.
int	size ()
	Get the number of available values.
float	min ()
	Lower bound on outputted values.
float	max ()
	Upper bound on outputted values.
void	setFloat (string key, float value)
	Set a double parameter (available : none)
void	setInt (string key, int value)
	Set a int parameter (available : "bound")
float	getFloat (string key)
	Get a double parameter (available : none)
int	getInt (string key)
	Get a int parameter (available : "bound")
void	setWindow (FTWindow win)
	Change the window (the default is WINDOW_RECTANGULAR)
void	watch ()
	Watching thread.
Public Member Functions inherited from FeatureExtractor
	FeatureExtractor (int chunkSize=0)
	Constructor. Can set the typical chunk size.
virtual	~FeatureExtractor ()
	Virtual destructor : enables each extractor to delete arrays.
bool	extract (std::deque< uint16_t > data, int size, size_t start)
	Idem, but the buffer starts at index start instead (circular buffer)
virtual float	safeValue (int index=0)
	Retrieve the results, with the bounds respected (we apply a min / max)
virtual float	value (int index, float low, float high)
	Retrieve the results, with other bounds.
virtual void	setString (string key, string value)
	Set a string parameter.
virtual string	getString (string key)
	Get a string parameter.
virtual void	clear ()
	Clear the memory of the extractor (so that the previously computed results don't infer to the next ones)

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Detailed Description

Retrives the spectrum using FFT.

Todo:

Implement overlapping : the results would be better if the frames were overlapping a bit (2/3) See http://oxygene.sk/lukas/2011/01/how-does-chromaprint-work/

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Constructor & Destructor Documentation

SpectrumExtr::SpectrumExtr

(

int

chunkSize = 0

)

Memory management.

Inits the FFT algorithm

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Member Function Documentation

bool SpectrumExtr::extract ( std::deque< uint16_t >  data, int  size  )

virtual

Algorithm.

Run the algorithm

Implements FeatureExtractor.

void SpectrumExtr::reallocate

(

)

Reallocate buffers based on the new size (plus butterfly computation)

Create a new window cache

float SpectrumExtr::value ( int  index )

virtual

Accessors.

Retrieve the results (from the index).

Implements FeatureExtractor.

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The documentation for this class was generated from the following files:

• include/features/spectrum.h
• src/features/spectrum.cpp