Class: STFTSpectrogram::Spectrogram

Inherits:
Object
  • Object
show all
Defined in:
lib/stft/spectrogram.rb

Overview

Represents time-frequency spectrogram

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(audio, window_size, window_overlap) ⇒ Spectrogram

Returns a new instance of Spectrogram.



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# File 'lib/stft/spectrogram.rb', line 9

def initialize(audio, window_size, window_overlap)
  if window_size <= window_overlap
    raise ArgumentError, 'Window size cannot be <= window overlap!'
  end

  @windows = []
  @transformed = false
  audio.window_size = window_size
  audio.window_overlap = window_overlap
  split_to_windows(audio)
  audio.reset
end

Instance Attribute Details

#windows ⇒ Object (readonly)

Returns the value of attribute windows.



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# File 'lib/stft/spectrogram.rb', line 7

def windows
  @windows
end

Instance Method Details

#filter(low, high) ⇒ Object

Sets low and high frequency filters



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# File 'lib/stft/spectrogram.rb', line 47

def filter(low, high)
  @windows.each do |w|
    w.low = low
    w.high = high
  end
end

#freqs ⇒ Object

Returns an array with all frequencies



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# File 'lib/stft/spectrogram.rb', line 41

def freqs
  return [] unless transformed?
  @windows[0].freqs
end

#max_freq ⇒ Object

Gets the highest frequency



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# File 'lib/stft/spectrogram.rb', line 35

def max_freq
  return 0 unless transformed?
  @windows[0].max_freq
end

#transform! ⇒ Object

Performs FFT on all timed data windows



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# File 'lib/stft/spectrogram.rb', line 29

def transform!
  @windows.each(&:do_fft!)
  @transformed = true
end

#transformed? ⇒ Boolean

Returns true if FFT was already performed

Returns:

  • (Boolean) 


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# File 'lib/stft/spectrogram.rb', line 55

def transformed?
  @transformed
end