dsp

Documentation

Overview

Package dsp provides audio analysis

Some notes:

https://dlbeer.co.nz/articles/fftvis.html https://www.cg.tuwien.ac.at/courses/WissArbeiten/WS2010/processing.pdf https://github.com/hvianna/audioMotion-analyzer/blob/master/src/audioMotion-analyzer.js#L1053 https://dsp.stackexchange.com/questions/6499/help-calculating-understanding-the-mfccs-mel-frequency-cepstrum-coefficients https://stackoverflow.com/questions/3694918/how-to-extract-frequency-associated-with-fft-values-in-python

• https://stackoverflow.com/a/27191172

Index

• type Analyzer
  • func NewAnalyzer(cfg AnalyzerConfig) Analyzer
• type AnalyzerConfig
• type BinMethod
  • func AverageSamples() BinMethod
  • func MaxSampleValue() BinMethod
  • func MinNonZeroSampleValue() BinMethod
  • func SumSamples() BinMethod
• type Smoother
  • func NewSmoother(cfg SmootherConfig) Smoother
• type SmootherConfig
• type SmoothingMethod

Types

type Analyzer

type Analyzer interface {
	BinCount() int
	ProcessBin(int, []complex128) float64
	Recalculate(int) int
}

func NewAnalyzer

func NewAnalyzer(cfg AnalyzerConfig) Analyzer

type AnalyzerConfig

type AnalyzerConfig struct {
	SampleRate    float64   // audio sample rate
	SampleSize    int       // number of samples per slice
	SquashLow     bool      // squash the low end the spectrum
	SquashLowOld  bool      // squash the low end using the old method
	DontNormalize bool      // dont run math.Log on output
	BinMethod     BinMethod // method used for calculating bin value
}

type BinMethod

type BinMethod func(int, float64, float64) float64

func AverageSamples

func AverageSamples() BinMethod

Average all the samples together.

func MaxSampleValue

func MaxSampleValue() BinMethod

Return the maximum value of all the samples.

func MinNonZeroSampleValue

func MinNonZeroSampleValue() BinMethod

Return the minimum value of all the samples that is not zero.

func SumSamples

func SumSamples() BinMethod

Sum all the samples together.

type Smoother

type Smoother interface {
	SmoothBuffers([][]float64)
	SmoothBin(int, int, float64) float64
	GetMethod() SmoothingMethod
	SetMethod(SmoothingMethod)
}

func NewSmoother

func NewSmoother(cfg SmootherConfig) Smoother

type SmootherConfig

type SmootherConfig struct {
	AverageSize     int             // size of window for average methods
	ChannelCount    int             // number of channels
	SampleSize      int             // number of samples per slice
	SampleRate      float64         // sample rate
	SmoothingFactor float64         // smoothing factor
	SmoothingMethod SmoothingMethod // smoothing method
}

type SmoothingMethod

type SmoothingMethod int

const (
	SmoothMin           SmoothingMethod = iota // 0
	SmoothSimple                               // 1
	SmoothAverage                              // 2
	SmoothSimpleAverage                        // 3
	SmoothNew                                  // 4
	SmoothNewAverage                           // 5
	SmoothNone                                 // 6
	SmoothMax                                  // 7

	SmoothDefault = SmoothSimpleAverage
)