MHAFilter::smoothspec_t Class Reference

Smooth spectral gains, create a windowed impulse response. More...

Public Member Functions
	smoothspec_t (unsigned int fftlen, unsigned int nchannels, const MHAWindow::base_t &window, bool minphase, bool linphase_asym=false)
	Constructor. More...
void	smoothspec (const mha_spec_t &s_in, mha_spec_t &s_out)
	Create a smoothed spectrum. More...
void	smoothspec (mha_spec_t &spec)
	Create a smoothed spectrum (in place) More...
void	spec2fir (const mha_spec_t &spec, mha_wave_t &fir)
	Return FIR coefficients. More...
	~smoothspec_t ()

Private Member Functions
void	internal_fir (const mha_spec_t &)

Private Attributes
unsigned int	fftlen
unsigned int	nchannels
MHAWindow::base_t	window
MHASignal::waveform_t	tmp_wave
MHASignal::spectrum_t	tmp_spec
MHASignal::minphase_t *	minphase
bool	_linphase_asym
mha_fft_t	fft

Detailed Description

Smooth spectral gains, create a windowed impulse response.

Spectral gains are smoothed by multiplying the impulse response with a window function.

If a minimal phase is used, then the original phase is discarded and replaced by the minimal phase function. In this case, the window is applied to the beginning of the inverse Fourier transform of the input spectrum, and the remaining signal set to zero. If the original phase is kept, the window is applied symmetrically arround zero, i.e. to the first and last samples of the inverse Fourier transform of the input spectrum. The spec2fir() function creates a causal impulse response by circularly shifting the impulse response by half of the window length.

The signal dimensions of the arguments of smoothspec() must correspond to the FFT length and number of channels provided in the constructor. The function spec2fir() can fill signal structures with more than window length frames.

Constructor & Destructor Documentation

smoothspec_t()

MHAFilter::smoothspec_t::smoothspec_t	(	unsigned int	fftlen,
		unsigned int	nchannels,
		const MHAWindow::base_t &	window,
		bool	minphase,
		bool	linphase_asym = false
	)

Constructor.

Parameters

fftlen	FFT length of input spectrum (fftlen/2+1 bins)
nchannels	Number of channels in input spectrum
window	Window used for smoothing
minphase	Use minimal phase (true) or original phase (false)
linphase_asym	Keep phase, but apply full window at beginning of IRS

~smoothspec_t()

MHAFilter::smoothspec_t::~smoothspec_t

(

)

Member Function Documentation

smoothspec() [1/2]

void MHAFilter::smoothspec_t::smoothspec	(	const mha_spec_t &	s_in,
		mha_spec_t &	s_out
	)

Create a smoothed spectrum.

Parameters

s_in	Input spectrum

Return values

s_out

Output spectrum

smoothspec() [2/2]

void MHAFilter::smoothspec_t::smoothspec ( mha_spec_t &  spec )

inline

Create a smoothed spectrum (in place)

Parameters

spec	Spectrum to be smoothed.

spec2fir()

void MHAFilter::smoothspec_t::spec2fir	(	const mha_spec_t &	spec,
		mha_wave_t &	fir
	)

Return FIR coefficients.

Parameters

spec	Input spectrum

Return values

fir	FIR coefficients, minimum length is window length

internal_fir()

void MHAFilter::smoothspec_t::internal_fir ( const mha_spec_t &  s_in )

private

Member Data Documentation

fftlen

unsigned int MHAFilter::smoothspec_t::fftlen

private

nchannels

unsigned int MHAFilter::smoothspec_t::nchannels

private

window

MHAWindow::base_t MHAFilter::smoothspec_t::window

private

tmp_wave

MHASignal::waveform_t MHAFilter::smoothspec_t::tmp_wave

private

tmp_spec

MHASignal::spectrum_t MHAFilter::smoothspec_t::tmp_spec

private

minphase

MHASignal::minphase_t* MHAFilter::smoothspec_t::minphase

private

_linphase_asym

bool MHAFilter::smoothspec_t::_linphase_asym

private

fft

mha_fft_t MHAFilter::smoothspec_t::fft

private

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

• mha_filter.hh
• mha_filter.cpp