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Panning extends BaseAlgorithm
in package

Panning

Inputs:

[vector_real] spectrumLeft - left channel's spectrum [vector_real] spectrumRight - right channel's spectrum

Outputs:

[matrix_real] panningCoeffs - parameters that define the panning curve at each frame

Parameters:

averageFrames: integer ∈ [0,inf) (default = 43) number of frames to take into account for averaging

numBands: integer ∈ [1,inf) (default = 1) number of mel bands

numCoeffs: integer ∈ (0,inf) (default = 20) number of coefficients used to define the panning curve at each frame

panningBins: integer ∈ (1,inf) (default = 512) size of panorama histogram (in bins)

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

warpedPanorama: bool ∈ {false,true} (default = true) if true, warped panorama is applied, having more resolution in the center area

Description:

This algorithm characterizes panorama distribution by comparing spectra from the left and right channels. The panning coefficients are extracted by:

  • determining the spatial location of frequency bins given left and right channel spectra;

  • computing panorama histogram weighted by the energy of frequency bins, averaging it across frames and normalizing;

  • converting the normalized histogram into panning coefficients (IFFT of the log-histogram).

The resulting coefficients will show peaks on the initial bins for left panned audio, and right panning will appear as peaks in the upper bins.

Since panning can vary very rapidly from one frame to the next, the coefficients can be averaged over a time window of several frames by specifying "averageFrames" parameter. If a single vector of panning coefficients for the whole audio input is required, "averageFrames" should correspond to the length of audio input. In standard mode, sequential runs of compute() method on each frame are required for averaging across frames.

Application: music classification, in particular genre classification [2].

Note: At present time, the original algorithm has not been tested in multi-band mode. That is, numBands must remain 1. References: [1] E. Gómez, P. Herrera, P. Cano, J. Janer, J. Serrà, J. Bonada, S. El-Hajj, T. Aussenac, and G. Holmberg, "Music similarity systems and methods using descriptors,” U.S. Patent WO 2009/0012022009.

[2] Guaus, E. (2009). Audio content processing for automatic music genre classification: descriptors, databases, and classifiers. PhD Thesis.

Category: Standard 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 = 'Panning'

$category

protected string $category = 'Standard'

$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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