Basic Processing

These are simple building blocks for processing data. For a list of all processing blocks, see Processing. More...


Data Structures
class	BeatReferee
	Central agency responsible for causally evaluating a pool of active BeatAgents around each beat prediction, and selecting the best one at each time ("frame" - tick), based on a given heuristics (score function) which affers the goodness-of-fit between each agent prediction and local maxima in the observed data (given by the onset detection function calculated by the Spectral Flux). More...
class	CARFAC
	Multiply input realvec with a fixed value. More...
class	Deinterleave
	Deinterleave i.e. Reorder input realvec along observations. More...
class	DeInterleaveSizecontrol
	Deinterleave i.e. Reorder input realvec. More...
class	Delay
	Delay. More...
class	Differentiator
	Calculate the difference of successive input samples. More...
class	DownSampler
	Downsample the input signal by dropping samples. More...
class	Gain
	Multiply input realvec with a fixed value. More...
class	HalfWaveRectifier
	Negative values are trimmed to zero, positive values are kept. More...
class	Memory
	Memory output the past memSize input observations. More...
class	Mono2Stereo
	Convert mono to stereo by copying. More...
class	Negative
	Toggle the sign of the input samples. More...
class	OnsetTimes
	Retrieves M first beat times (phases, in "frames"-ticks), retrieved from peaks from an onset function. More...
class	OrcaSnip
	Multiply input realvec with OrcaSnip. More...
class	OverlapAdd
	OverlapAdd. More...
class	PeakRatio
	Incorporates the ratio of the higest peak to minimal/average peak of each observation samplewise to the output vector. More...
class	Resample
	resamples all observations using a piecewise cubic bezier polynomial for interpolation between samples More...
class	ResampleBezier
	resamples all observations using a piecewise cubic bezier polynomial for interpolation between samples More...
class	ResampleSinc
	resamples all observations using a sum of sinc functions wheareas each point is modeled by a sinc function with the given points amplitude, that is set to zero after the 5th zero crossing More...
class	Reverse
	Reverse the input samples (i.e. first samples become last and vice-versa). More...
class	Shifter
	Shifts the input and outputs the original and shifted version. More...
class	ShiftInput
	Apply sliding window with certain hop size and window size. More...
class	ShiftOuput
	Shift next D samples. More...
class	Signum
	Compute sign of input vector: output vector is 1 for strictly positive observations, 0 for the rest. More...
class	SimulMaskingFft
	Return only the power spectrum components above the masking threshold. More...
class	Square
	Square the input samples. More...
class	Sum
	Sum the input rows of observations into one row. More...
class	Transposer
	switches samples and observations, i.e. transposes the output realvec (inSamples -> onObservations, onSamples -> inObservations) More...
class	Unfold
	Take a two-dimesional realvec and unfold it to make a one-dimensional realvec. More...
class	Windowing
	Apply a windowing function (envelope) to the input signal. More...
Functions
void	windowingFillBartlett (realvec &envelope)
	Bartlett window function (triangle window with zero endpoints).
void	windowingFillBlackman (realvec &envelope, mrs_real alpha=0.16)
	Blackman window function.
void	windowingFillBlackmanHarris (realvec &envelope)
	Blackman-Harris window function.
void	windowingFillCosine (realvec &envelope)
	Cosine (aka sine) window function.
void	windowingFillGaussian (realvec &envelope, mrs_real sigma)
	Gaussian window function.
void	windowingFillHamming (realvec &envelope)
	Hamming window function.
void	windowingFillHanning (realvec &envelope)
	Hanning window function.
void	windowingFillRaisedCosine (realvec &envelope, mrs_real alpha, mrs_real beta)
	Helper function for generating a raised cosine window function.
void	windowingFillTriangle (realvec &envelope)
	Triangle window function (non zero endpoints).

Detailed Description

These are simple building blocks for processing data. For a list of all processing blocks, see Processing.

Function Documentation

void windowingFillBartlett ( realvec & envelope )

Bartlett window function (triangle window with zero endpoints).

$w(n) = \frac{2}{N-1}\cdot\left(\frac{N-1}{2}-\left |n-\frac{N-1}{2}\right |\right)$

See also:

windowingFillRaisedCosine(),

windowingFillTriangle(),

Windowing

Definition at line 281 of file Windowing.cpp.

References realvec::getSize().

void windowingFillBlackman	(	realvec &	envelope,
		mrs_real	alpha
	)

Blackman window function.

$w(n) = a_0 - a_1 \cos \left ( \frac{2 \pi n}{N-1} \right) + a_2 \cos \left ( \frac{4 \pi n}{N-1} \right)$

with $a_0=\frac{1-\alpha}{2}$ , $a_1=\frac{1}{2}$ and $a_2=\frac{\alpha}{2}$

See also:

windowingFillRaisedCosine(),

windowingFillBlackmanHarris(),

Windowing

Definition at line 315 of file Windowing.cpp.

References realvec::getSize().

void windowingFillBlackmanHarris ( realvec & envelope )

Blackman-Harris window function.

$w(n) = a_0 - a_1 \cos \left ( \frac{2 \pi n}{N-1} \right)+ a_2 \cos \left ( \frac{4 \pi n}{N-1} \right)- a_3 \cos \left ( \frac{6 \pi n}{N-1} \right)$

with $ a_0=0.35875 $ , $ a_1=0.48829 $ , $ a_2=0.14128 $ and $ a_3=0.01168 $

See also:

windowingFillRaisedCosine(),

windowingFillBlackman(),

Windowing

Definition at line 335 of file Windowing.cpp.

References realvec::getSize().

void windowingFillCosine ( realvec & envelope )

Cosine (aka sine) window function.

$w(n) = \sin \left( \pi \frac{n}{N-1} \right)$

See also:: windowingFillRaisedCosine(),
Windowing

Definition at line 354 of file Windowing.cpp.

References realvec::getSize().

void windowingFillGaussian	(	realvec &	envelope,
		mrs_real	sigma
	)

Gaussian window function.

$w(n) = \exp \left( -\frac{1}{2} \left( \frac{n-(N-1)/2}{\sigma (N-1)/2} \right)^{2} \right)$

See also:: windowingFillRaisedCosine(),
Windowing

Definition at line 297 of file Windowing.cpp.

References realvec::getSize().

void Marsyas::windowingFillHamming ( realvec & envelope ) [inline]

Hamming window function.

$w(n) = 0.54 - 0.46 \cos \left ( \frac{2\pi n}{N-1} \right)$

See also:: windowingFillRaisedCosine()
Windowing

Definition at line 90 of file Windowing.h.

References Marsyas::windowingFillRaisedCosine().

void Marsyas::windowingFillHanning ( realvec & envelope ) [inline]

Hanning window function.

$w(n) = 0.5 - 0.5 \cos \left ( \frac{2\pi n}{N-1} \right)$

See also:: windowingFillRaisedCosine()
Windowing

Definition at line 105 of file Windowing.h.

References Marsyas::windowingFillRaisedCosine().

void windowingFillRaisedCosine	(	realvec &	envelope,
		mrs_real	alpha,
		mrs_real	beta
	)

Helper function for generating a raised cosine window function.

A raised cosine window $ w(t) $ is of the form

$w(t) = \alpha + \beta \cos \left( \frac{2 \pi t}{N-1} \right)$

windowingFillRaisedCosine() fills a given realvec with the values $ w(t) $ for increasing values of $ t $ (note that the realvec is handled as a one dimensional array). The $ N $ is determined by the size of the realvec.