Centroid
extends BaseAlgorithm
in package
Centroid
Inputs:
[vector_real] array - the input array
Outputs:
[real] centroid - the centroid of the array
Parameters:
range: real ∈ (0,inf) (default = 1) the range of the input array, used for normalizing the results
Description:
This algorithm computes the centroid of an array. The centroid is normalized to a specified range. This algorithm can be used to compute spectral centroid or temporal centroid.
The spectral centroid is a measure that indicates where the "center of mass" of the spectrum is. Perceptually, it has a robust connection with the impression of "brightness" of a sound, and therefore is used to characterise musical timbre. It is calculated as the weighted mean of the frequencies present in the signal, with their magnitudes as the weights.
The temporal centroid is the point in time in a signal that is a temporal balancing point of the sound event energy. It can be computed from the envelope of the signal across audio samples [3] (see Envelope algorithm) or over the RMS level of signal across frames [4] (see RMS algorithm).
Note:
- For a spectral centroid [hz], frequency range should be equal to samplerate/2
- For a temporal envelope centroid [s], range should be equal to (audio_size_in_samples-1) / samplerate
- Exceptions are thrown when input array contains less than 2 elements.
References: [1] Function Centroid -- from Wolfram MathWorld, http://mathworld.wolfram.com/FunctionCentroid.html [2] Spectral centroid - Wikipedia, the free encyclopedia, https://en.wikipedia.org/wiki/Spectral_centroid [3] G. Peeters, "A large set of audio features for sound description (similarity and classification) in the CUIDADO project," CUIDADO I.S.T. Project Report, 2004. [4] Klapuri, A., & Davy, M. (Eds.). (2007). Signal processing methods for music transcription. Springer Science & Business Media.
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
= 'Centroid'
$category
protected
string
$category
= 'Spectral'
$essentia
protected
EssentiaFFI
$essentia
$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
stringgetCategory()
public
getCategory() : string
Return values
stringgetMode()
public
getMode() : string
Return values
stringgetParameters()
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
selfconfigure()
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
boolvalidateInput()
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
intexecuteAlgorithm()
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
stringgetValidParameters()
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