SoDa::Spectrogram Class Reference

Spectrogram generates magnitude buffers from input sample stream. More...

#include <Spectrogram.hxx>

Public Member Functions
	Spectrogram (unsigned int fftlen)
	Constructor. More...
void	apply_acc (std::complex< float > *invec, unsigned int inveclen, float *outvec, float accumulation_gain=0.0)
	Calculate the spectrogram from an input vector – add it to an accumulation buffer. More...
void	apply_max (std::complex< float > *invec, unsigned int inveclen, float *outvec, bool first=true)
	Calculate the spectrogram from an input vector – add it to an accumulation buffer. More...

Private Member Functions
float *	initBlackmanHarris ()
	all spectrograms are under a blackman harris window More...
void	apply_common (std::complex< float > *invec, unsigned int inveclen)
	this is the common spectrogram calculation (window + fft + mag) More...

Private Attributes
fftwf_plan	fftplan
float *	window
std::complex< float > *	win_samp
std::complex< float > *	fft_out
float *	result
unsigned int	fft_len

Detailed Description

Spectrogram generates magnitude buffers from input sample stream.

Definition at line 39 of file Spectrogram.hxx.

Constructor & Destructor Documentation

Spectrogram()

SoDa::Spectrogram::Spectrogram

(

unsigned int

fftlen

)

Constructor.

Parameters

fftlen

how many frequency points in the spectrogram buffer

Definition at line 34 of file Spectrogram.cxx.

References fft_len, fft_out, fftplan, initBlackmanHarris(), result, win_samp, and window.

Member Function Documentation

apply_acc()

void SoDa::Spectrogram::apply_acc	(	std::complex< float > *	invec,
		unsigned int	inveclen,
		float *	outvec,
		float	accumulation_gain = 0.0
	)

Calculate the spectrogram from an input vector – add it to an accumulation buffer.

Parameters

invec	the input sample buffer
inveclen	the length of the buffer
outvec	the result buffer
accumulation_gain	(out = result + out * acc_gain)

Definition at line 111 of file Spectrogram.cxx.

References apply_common(), fft_len, and result.

Referenced by SoDa::UI::sendFFT().

apply_common()

void SoDa::Spectrogram::apply_common ( std::complex< float > *  invec, unsigned int  inveclen  )

private

this is the common spectrogram calculation (window + fft + mag)

Parameters

invec	the input sample buffer
inveclen	the length of the buffer

Definition at line 74 of file Spectrogram.cxx.

References fft_len, fft_out, fftplan, result, win_samp, and window.

Referenced by apply_acc(), and apply_max().

apply_max()

void SoDa::Spectrogram::apply_max	(	std::complex< float > *	invec,
		unsigned int	inveclen,
		float *	outvec,
		bool	first = true
	)

Calculate the spectrogram from an input vector – add it to an accumulation buffer.

Parameters

invec	the input sample buffer
inveclen	the length of the buffer
outvec	the result buffer (out = max(result, out))
first	if true, ignore contents of outvec...

Definition at line 142 of file Spectrogram.cxx.

References apply_common(), fft_len, and result.

initBlackmanHarris()

float * SoDa::Spectrogram::initBlackmanHarris ( )

private

all spectrograms are under a blackman harris window

Definition at line 55 of file Spectrogram.cxx.

References fft_len.

Referenced by Spectrogram().

Member Data Documentation

fft_len

unsigned int SoDa::Spectrogram::fft_len

private

Definition at line 94 of file Spectrogram.hxx.

Referenced by apply_acc(), apply_common(), apply_max(), initBlackmanHarris(), and Spectrogram().

fft_out

std::complex<float>* SoDa::Spectrogram::fft_out

private

Definition at line 92 of file Spectrogram.hxx.

Referenced by apply_common(), and Spectrogram().

fftplan

fftwf_plan SoDa::Spectrogram::fftplan

private

Definition at line 89 of file Spectrogram.hxx.

Referenced by apply_common(), and Spectrogram().

result

float* SoDa::Spectrogram::result

private

Definition at line 93 of file Spectrogram.hxx.

Referenced by apply_acc(), apply_common(), apply_max(), and Spectrogram().

win_samp

std::complex<float>* SoDa::Spectrogram::win_samp

private

Definition at line 91 of file Spectrogram.hxx.

Referenced by apply_common(), and Spectrogram().

window

float* SoDa::Spectrogram::window

private

Definition at line 90 of file Spectrogram.hxx.

Referenced by apply_common(), and Spectrogram().

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

• src/Spectrogram.hxx
• src/Spectrogram.cxx