/Users/richardeakin/projects/libsms/trunk/src/windows.c File Reference

functions for creating various windows More...

#include "sms.h"

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Functions
void	sms_scaleWindow (int sizeWindow, sfloat *pWindow)
void	IFFTwindow (int sizeWindow, sfloat *pFWindow)
	window to be used in the IFFT synthesis
void	BlackmanHarris62 (int sizeWindow, sfloat *pFWindow)
	BlackmanHarris window with 62dB rolloff.
void	BlackmanHarris70 (int sizeWindow, sfloat *pFWindow)
	BlackmanHarris window with 70dB rolloff.
void	BlackmanHarris74 (int sizeWindow, sfloat *pFWindow)
	BlackmanHarris window with 74dB rolloff.
void	BlackmanHarris92 (int sizeWindow, sfloat *pFWindow)
	BlackmanHarris window with 92dB rolloff.
void	BlackmanHarris (int sizeWindow, sfloat *pFWindow)
	default BlackmanHarris window (70dB rolloff)
void	Hamming (int sizeWindow, sfloat *pWindow)
	Hamming window.
void	Hanning (int sizeWindow, sfloat *pWindow)
	Hanning window.
void	sms_getWindow (int sizeWindow, sfloat *pFWindow, int iWindowType)
	main function for getting various windows
void	sms_windowCentered (int sizeWindow, sfloat *pWaveform, sfloat *pWindow, int sizeFft, sfloat *pFftBuffer)
	apply a window and center around sample 0

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Detailed Description

functions for creating various windows

Use sms_getWindow() for selecting which window will be made

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Function Documentation

void BlackmanHarris	(	int	sizeWindow,
		sfloat *	pFWindow
	)

default BlackmanHarris window (70dB rolloff)

Parameters:

	sizeWindow	the size of the window
	pFWindow	pointer to an array that will hold the window

References BlackmanHarris70().

Referenced by sms_getWindow().

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void BlackmanHarris62	(	int	sizeWindow,
		sfloat *	pFWindow
	)

BlackmanHarris window with 62dB rolloff.

Todo:

where did these come from?

Parameters:

	sizeWindow	the size of the window
	pFWindow	pointer to an array that will hold the window

References sfloat, and TWO_PI.

Referenced by sms_getWindow().

void BlackmanHarris70	(	int	sizeWindow,
		sfloat *	pFWindow
	)

BlackmanHarris window with 70dB rolloff.

Parameters:

	sizeWindow	the size of the window
	pFWindow	pointer to an array that will hold the window

References sfloat, and TWO_PI.

Referenced by BlackmanHarris(), and sms_getWindow().

void BlackmanHarris74	(	int	sizeWindow,
		sfloat *	pFWindow
	)

BlackmanHarris window with 74dB rolloff.

Parameters:

	sizeWindow	the size of the window
	pFWindow	pointer to an array that will hold the window

References sfloat, and TWO_PI.

Referenced by sms_getWindow().

void BlackmanHarris92	(	int	sizeWindow,
		sfloat *	pFWindow
	)

BlackmanHarris window with 92dB rolloff.

Parameters:

	sizeWindow	the size of the window
	pFWindow	pointer to an array that will hold the window

References sfloat, and TWO_PI.

Referenced by sms_getWindow().

void Hamming	(	int	sizeWindow,
		sfloat *	pWindow
	)

Hamming window.

Parameters:

	sizeWindow	window size
	pWindow	window array

References sfloat, and TWO_PI.

Referenced by sms_getWindow().

void Hanning	(	int	sizeWindow,
		sfloat *	pWindow
	)

Hanning window.

Parameters:

	sizeWindow	window size
	pWindow	window array

References PI.

Referenced by sms_getWindow().

void IFFTwindow	(	int	sizeWindow,
		sfloat *	pFWindow
	)

window to be used in the IFFT synthesis

contains both an inverse Blackman-Harris and triangular window.

Todo:

read X. Rodet, Ph. Depalle, "Spectral Envelopes and Inverse FFT Synthesis." Proc. 93rd AES Convention, October 1992

Parameters:

	sizeWindow	the size of the window
	pFWindow	pointer to an array that will hold the window

References sfloat, and TWO_PI.

Referenced by sms_getWindow().

void sms_getWindow	(	int	sizeWindow,
		sfloat *	pFWindow,
		int	iWindowType
	)

main function for getting various windows

Todo:

note on window scales

See also:

SMS_WINDOWS for the different window types available

Parameters:

	sizeWindow	window size
	pFWindow	window array
	iWindowType	the desired window type defined by SMS_WINDOWS

References BlackmanHarris(), BlackmanHarris62(), BlackmanHarris70(), BlackmanHarris74(), BlackmanHarris92(), Hamming(), Hanning(), IFFTwindow(), SMS_WIN_BH_62, SMS_WIN_BH_70, SMS_WIN_BH_74, SMS_WIN_BH_92, SMS_WIN_HAMMING, SMS_WIN_HANNING, and SMS_WIN_IFFT.

Referenced by InitializeHybrid(), sms_analyze(), sms_analyzeFrame(), sms_changeSynthHop(), and sms_initSynth().

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void sms_scaleWindow	(	int	sizeWindow,
		sfloat *	pWindow
	)

References sfloat.

Referenced by sms_analyze(), and sms_analyzeFrame().

void sms_windowCentered	(	int	sizeWindow,
		sfloat *	pWaveform,
		sfloat *	pWindow,
		int	sizeFft,
		sfloat *	pFftBuffer
	)

apply a window and center around sample 0

function to center a waveform around sample 0, also known as 'zero-phase windowing'. Half the samples are at the beginning, half at the end, with the remaining samples (sizeFft-sizeWindow) in the middle (zero-padding for an interpolated spectrum).

Todo:

do I need to garuntee that sizeWindow is odd-lengthed?

Parameters:

	sizeWindow	size of waveform/waveform
	pWaveform	pointer to waveform
	pWindow	pointer to window
	sizeFft	size of FFT
	pFftBuffer	pointer to FFT buffer