CLAM::SpectralDescriptors Class Reference

#include <SpectralDescriptors.hxx>

Inheritance diagram for CLAM::SpectralDescriptors:

Detailed Description

Definition at line 38 of file SpectralDescriptors.hxx.


Public Member Functions
	DYNAMIC_TYPE_USING_INTERFACE (SpectralDescriptors, 21, Descriptor)
	DYN_ATTRIBUTE (0, public, TData, Mean)
	The spectral power mean value.
	DYN_ATTRIBUTE (1, public, TData, GeometricMean)
	The geometric mean for the spectral power values sequence.
	DYN_ATTRIBUTE (2, public, TData, Energy)
	The squared sum of spectral power distribution values.
	DYN_ATTRIBUTE (3, public, TData, Centroid)
	The frequency where the center of mass of the spectral power distribution lies.
	DYN_ATTRIBUTE (4, public, TData, Moment2)
	DYN_ATTRIBUTE (5, public, TData, Moment3)
	DYN_ATTRIBUTE (6, public, TData, Moment4)
	DYN_ATTRIBUTE (7, public, TData, Moment5)
	DYN_ATTRIBUTE (8, public, TData, Moment6)
	DYN_ATTRIBUTE (9, public, TData, Flatness)
	DYN_ATTRIBUTE (10, public, TData, MagnitudeKurtosis)
	DYN_ATTRIBUTE (11, public, Array< TData >, MFCC)
	DYN_ATTRIBUTE (12, public, TData, MaxMagFreq)
	Frequency of the maximum magnitude of the spectrum normalized by the spectral range.
	DYN_ATTRIBUTE (13, public, TData, LowFreqEnergyRelation)
	The ratio between the energy over 0-100 Hz band and the whole spectrum energy.
	DYN_ATTRIBUTE (14, public, TData, Spread)
	The spectral spread is the variation of the spectrum around its mean value.
	DYN_ATTRIBUTE (15, public, TData, MagnitudeSkewness)
	DYN_ATTRIBUTE (16, public, TData, Rolloff)
	The spectral roll-off point is the frequency value so that the 85% of the spectral energy is contained below it.
	DYN_ATTRIBUTE (17, public, TData, Slope)
	The spectral slope represents the amount of decreasing of the spectral magnitude.
	DYN_ATTRIBUTE (18, public, TData, HighFrequencyContent)
	Sum of the squared spectrum magnitude multiplied by the wave number of the bin.
	DYN_ATTRIBUTE (19, public, Array< SpectralDescriptors >, BandDescriptors)
	DYN_ATTRIBUTE (20, public, Array< TData >, PCP)
	SpectralDescriptors (Spectrum *pSpectrum)
	SpectralDescriptors (TData initVal)
const Spectrum *	GetpSpectrum () const
void	SetpSpectrum (Spectrum *pSpectrum)
void	ConcreteCompute ()
void	DefaultInit ()
	The concrete dynamic type constructor calls DefaultInit().
void	CopyInit (const SpectralDescriptors &copied)
TData	ComputeSpectralFlatness ()
TData	ComputeHighFrequencyContent ()
TData	ComputeMaxMagFreq ()
	It computes the frequency where the spectrum has its maximum value.
TData	ComputeLowFreqEnergyRelation ()
TData	ComputeRolloff ()
TData	ComputeSpread ()
TData	ComputeSlope ()

Constructor & Destructor Documentation

CLAM::SpectralDescriptors::SpectralDescriptors ( Spectrum * pSpectrum )

Definition at line 101 of file SpectralDescriptors.cxx.

References CLAM_ASSERT, and CLAM::EScale::eLinear.

CLAM::SpectralDescriptors::SpectralDescriptors ( TData initVal )

Definition at line 109 of file SpectralDescriptors.cxx.

References CLAM::DynamicType::UpdateData().

Member Function Documentation

CLAM::SpectralDescriptors::DYNAMIC_TYPE_USING_INTERFACE	(	SpectralDescriptors	,
		21	,
		Descriptor
	)

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	0	,
		public	,
		TData	,
		Mean
	)

The spectral power mean value.

The unit of this measure can be dB or none, depending on the scale set for the measured Spectrum object.

See also:

Spectrum::SetScale

EScale

Stats::GetMean

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	1	,
		public	,
		TData	,
		GeometricMean
	)

The geometric mean for the spectral power values sequence.

See this for a definition of this pythagorean mean. Note that computing this measurement over long sequences of small real numbers ( as the ones one usually founds in spectral power distributions derived of audio windowed with a normalized window function ) pose a numerical problem. To avoid this, computation of Geometric mean is restricted to Log scale Spectral Power Distributions since this allows to change the product for a summation.

This measure is expressed in dBs.

See also:: Stats::GetGeometricMean

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	2	,
		public	,
		TData	,
		Energy
	)

The squared sum of spectral power distribution values.

This measure comes in the same units as the distribution values.

See also:: Stats::GetEnergy

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	3	,
		public	,
		TData	,
		Centroid
	)

The frequency where the center of mass of the spectral power distribution lies.

This measure is expressed in Hz.

See also:: Stats::GetCentroid

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	4	,
		public	,
		TData	,
		Moment2
	)

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	5	,
		public	,
		TData	,
		Moment3
	)

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	6	,
		public	,
		TData	,
		Moment4
	)

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	7	,
		public	,
		TData	,
		Moment5
	)

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	8	,
		public	,
		TData	,
		Moment6
	)

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	9	,
		public	,
		TData	,
		Flatness
	)

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	10	,
		public	,
		TData	,
		MagnitudeKurtosis
	)

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	11	,
		public	,
		Array< TData >	,
		MFCC
	)

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	12	,
		public	,
		TData	,
		MaxMagFreq
	)

Frequency of the maximum magnitude of the spectrum normalized by the spectral range.

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	13	,
		public	,
		TData	,
		LowFreqEnergyRelation
	)

The ratio between the energy over 0-100 Hz band and the whole spectrum energy.

To avoid singularities while keeping descriptor continuity, when the whole spectrum energy drops bellow $10^{-4}$, such value is considered as whole spectrum energy.

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	14	,
		public	,
		TData	,
		Spread
	)

The spectral spread is the variation of the spectrum around its mean value.

It's computed from the second order moment.

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	15	,
		public	,
		TData	,
		MagnitudeSkewness
	)

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	16	,
		public	,
		TData	,
		Rolloff
	)

The spectral roll-off point is the frequency value so that the 85% of the spectral energy is contained below it.

For silences this is 0Hz. Measured in Hz.

$Rolloff / \sum_{f=0}^{RollOff} {a_f^2} = 0.85 \times \sum_{f=0}^{SpectralRange} {a_f^2}$

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	17	,
		public	,
		TData	,
		Slope
	)

The spectral slope represents the amount of decreasing of the spectral magnitude.

Measured in ??.

See also:: Stats::Slope

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	18	,
		public	,
		TData	,
		HighFrequencyContent
	)

Sum of the squared spectrum magnitude multiplied by the wave number of the bin.

It could be considered the energy derivative, a high pass filter, which gives higher values for high frequency content.

$HighFrequencyContent = \sum_{i=0}^{nBins} i magnitude_i^2$

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	19	,
		public	,
		Array< SpectralDescriptors >	,
		BandDescriptors
	)

CLAM::SpectralDescriptors::DYN_ATTRIBUTE	(	20	,
		public	,
		Array< TData >	,
		PCP
	)

const Spectrum * CLAM::SpectralDescriptors::GetpSpectrum ( ) const

Definition at line 146 of file SpectralDescriptors.cxx.

void CLAM::SpectralDescriptors::SetpSpectrum ( Spectrum * pSpectrum )

Definition at line 151 of file SpectralDescriptors.cxx.

References CLAM_ASSERT, CLAM::EScale::eLinear, and CLAM::DescriptorTmpl< abs >::InitStats().

void CLAM::SpectralDescriptors::ConcreteCompute ( ) [virtual]

Implements CLAM::DescriptorTmpl< abs >.

Definition at line 165 of file SpectralDescriptors.cxx.

void CLAM::SpectralDescriptors::DefaultInit ( void )

The concrete dynamic type constructor calls DefaultInit().

This allows user to initialize his/her object. But we define DefaultInit() here because we don't want to force writting one DefaultInit() function for each concrete dynamic type. If a dynamic type concrete class defines some (not-default) constructors, this should also call the DefaultInit().