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BFCC extends BaseAlgorithm
in package

BFCC

Inputs:

[vector_real] spectrum - the audio spectrum

Outputs:

[vector_real] bands - the energies in bark bands [vector_real] bfcc - the bark frequency cepstrum coefficients

Parameters:

dctType: integer ∈ [2,3] (default = 2) the DCT type

highFrequencyBound: real ∈ (0,inf) (default = 11000) the upper bound of the frequency range [Hz]

inputSize: integer ∈ (1,inf) (default = 1025) the size of input spectrum

liftering: integer ∈ [0,inf) (default = 0) the liftering coefficient. Use '0' to bypass it

logType: string ∈ {natural,dbpow,dbamp,log} (default = "dbamp") logarithmic compression type. Use 'dbpow' if working with power and 'dbamp' if working with magnitudes

lowFrequencyBound: real ∈ [0,inf) (default = 0) the lower bound of the frequency range [Hz]

normalize: string ∈ {unit_sum,unit_max} (default = "unit_sum") 'unit_max' makes the vertex of all the triangles equal to 1, 'unit_sum' makes the area of all the triangles equal to 1

numberBands: integer ∈ [1,inf) (default = 40) the number of bark bands in the filter

numberCoefficients: integer ∈ [1,inf) (default = 13) the number of output cepstrum coefficients

sampleRate: real ∈ (0,inf) (default = 44100) the sampling rate of the audio signal [Hz]

type: string ∈ {magnitude,power} (default = "power") use magnitude or power spectrum

weighting: string ∈ {warping,linear} (default = "warping") type of weighting function for determining triangle area

Description:

This algorithm computes the bark-frequency cepstrum coefficients of a spectrum. Bark bands and their subsequent usage in cepstral analysis have shown to be useful in percussive content [1, 2] This algorithm is implemented using the Bark scaling approach in the Rastamat version of the MFCC algorithm and in a similar manner to the MFCC-FB40 default specs:

http://www.ee.columbia.edu/ln/rosa/matlab/rastamat/

  • filterbank of 40 bands from 0 to 11000Hz
  • take the log value of the spectrum energy in each bark band
  • DCT of the 40 bands down to 13 mel coefficients

The parameters of this algorithm can be configured in order to behave like Rastamat [3] as follows:

  • type = 'power'
  • weighting = 'linear'
  • lowFrequencyBound = 0
  • highFrequencyBound = 8000
  • numberBands = 26
  • numberCoefficients = 13
  • normalize = 'unit_max'
  • dctType = 3
  • logType = 'log'
  • liftering = 22

In order to completely behave like Rastamat the audio signal has to be scaled by 2^15 before the processing and if the Windowing and FrameCutter algorithms are used they should also be configured as follows.

FrameGenerator:

  • frameSize = 1102
  • hopSize = 441
  • startFromZero = True
  • validFrameThresholdRatio = 1

Windowing:

  • type = 'hann'
  • size = 1102
  • zeroPadding = 946
  • normalized = False

This algorithm depends on the algorithms TriangularBarkBands (not the regular BarkBands algo as it is non-configurable) and DCT and therefore inherits their parameter restrictions. An exception is thrown if any of these restrictions are not met. The input "spectrum" is passed to the TriangularBarkBands algorithm and thus imposes TriangularBarkBands' input requirements. Exceptions are inherited by TriangualrBarkBands as well as by DCT.

References: [1] P. Herrera, A. Dehamel, and F. Gouyon, "Automatic labeling of unpitched percussion sounds in Audio Engineering Society 114th Convention, 2003, [2] W. Brent, "Cepstral Analysis Tools for Percussive Timbre Identification in Proceedings of the 3rd International Pure Data Convention, Sao Paulo, Brazil, 2009,

Category: Spectral Mode: standard

Table of Contents

Properties

$algorithmName  : string
$category  : string
$essentia  : EssentiaFFI
$mode  : string
$parameters  : array<string|int, mixed>
$algorithmHandle  : CData|null
$configured  : bool

Methods

__construct()  : mixed
__destruct()  : mixed
compute()  : array<string|int, mixed>
getAlgorithmName()  : string
getCategory()  : string
getMode()  : string
getParameters()  : array<string|int, mixed>
setParameter()  : self
configure()  : void
isValidParameter()  : bool
validateInput()  : void
cleanupAlgorithm()  : void
configureAlgorithmParameters()  : void
estimateOutputSize()  : int
executeAlgorithm()  : array<string|int, mixed>
executeGenericAlgorithm()  : array<string|int, mixed>
executeSpecificAlgorithm()  : array<string|int, mixed>
getAlgorithmCreateFunction()  : string
getValidParameters()  : array<string|int, mixed>
initializeAlgorithm()  : void
prepareInput()  : mixed
processOutput()  : array<string|int, mixed>
processRhythmOutput()  : array<string|int, mixed>
processSpectralOutput()  : array<string|int, mixed>
processStatsOutput()  : array<string|int, mixed>
processTemporalOutput()  : array<string|int, mixed>
processTonalOutput()  : array<string|int, mixed>
setAlgorithmParameter()  : void
setArrayParameter()  : void
validateAlgorithmInput()  : void

Properties

$algorithmName

protected string $algorithmName = 'BFCC'

$category

protected string $category = 'Spectral'

$mode

protected string $mode = 'standard'

$parameters

protected array<string|int, mixed> $parameters = []

$algorithmHandle

private CData|null $algorithmHandle = null

$configured

private bool $configured = false

Methods

__construct()

public __construct([array<string|int, mixed> $parameters = [] ]) : mixed
Parameters
$parameters : array<string|int, mixed> = []

__destruct()

public __destruct() : mixed

compute()

public compute(mixed $input) : array<string|int, mixed>
Parameters
$input : mixed
Return values
array<string|int, mixed>

getAlgorithmName()

public getAlgorithmName() : string
Return values
string

getCategory()

public getCategory() : string
Return values
string

getParameters()

public getParameters() : array<string|int, mixed>
Return values
array<string|int, mixed>

setParameter()

public setParameter(string $key, mixed $value) : self
Parameters
$key : string
$value : mixed
Return values
self

configure()

protected configure(array<string|int, mixed> $parameters) : void
Parameters
$parameters : array<string|int, mixed>

isValidParameter()

protected isValidParameter(string $parameter) : bool
Parameters
$parameter : string
Return values
bool

validateInput()

protected validateInput(mixed $input, string $expectedType) : void
Parameters
$input : mixed
$expectedType : string

cleanupAlgorithm()

private cleanupAlgorithm() : void

configureAlgorithmParameters()

private configureAlgorithmParameters() : void

estimateOutputSize()

private estimateOutputSize(mixed $input) : int
Parameters
$input : mixed
Return values
int

executeAlgorithm()

private executeAlgorithm(mixed $input) : array<string|int, mixed>
Parameters
$input : mixed
Return values
array<string|int, mixed>

executeGenericAlgorithm()

private executeGenericAlgorithm(FFI $ffi, mixed $input) : array<string|int, mixed>
Parameters
$ffi : FFI
$input : mixed
Return values
array<string|int, mixed>

executeSpecificAlgorithm()

private executeSpecificAlgorithm(FFI $ffi, mixed $input) : array<string|int, mixed>
Parameters
$ffi : FFI
$input : mixed
Return values
array<string|int, mixed>

getAlgorithmCreateFunction()

private getAlgorithmCreateFunction() : string
Return values
string

getValidParameters()

private getValidParameters() : array<string|int, mixed>
Return values
array<string|int, mixed>

initializeAlgorithm()

private initializeAlgorithm() : void

prepareInput()

private prepareInput(mixed $input) : mixed
Parameters
$input : mixed

processOutput()

private processOutput(array<string|int, mixed> $result) : array<string|int, mixed>
Parameters
$result : array<string|int, mixed>
Return values
array<string|int, mixed>

processRhythmOutput()

private processRhythmOutput(array<string|int, mixed> $result) : array<string|int, mixed>
Parameters
$result : array<string|int, mixed>
Return values
array<string|int, mixed>

processSpectralOutput()

private processSpectralOutput(array<string|int, mixed> $result) : array<string|int, mixed>
Parameters
$result : array<string|int, mixed>
Return values
array<string|int, mixed>

processStatsOutput()

private processStatsOutput(array<string|int, mixed> $result) : array<string|int, mixed>
Parameters
$result : array<string|int, mixed>
Return values
array<string|int, mixed>

processTemporalOutput()

private processTemporalOutput(array<string|int, mixed> $result) : array<string|int, mixed>
Parameters
$result : array<string|int, mixed>
Return values
array<string|int, mixed>

processTonalOutput()

private processTonalOutput(array<string|int, mixed> $result) : array<string|int, mixed>
Parameters
$result : array<string|int, mixed>
Return values
array<string|int, mixed>

setAlgorithmParameter()

private setAlgorithmParameter(FFI $ffi, string $key, mixed $value) : void
Parameters
$ffi : FFI
$key : string
$value : mixed

setArrayParameter()

private setArrayParameter(FFI $ffi, string $key, array<string|int, mixed> $value) : void
Parameters
$ffi : FFI
$key : string
$value : array<string|int, mixed>

validateAlgorithmInput()

private validateAlgorithmInput(mixed $input) : void
Parameters
$input : mixed 

        

        
    




    

    

                                

                

                                
    

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