Module: Muze::Beat

Defined in:
lib/muze/beat/beat_track.rb

Overview

Beat tracking functions.

Class Method Summary collapse

Class Method Details

.beat_track(y: nil, sr: 22_050, onset_envelope: nil, hop_length: 512, start_bpm: 120.0, tightness: 100, min_bpm: 30.0, max_bpm: 240.0, bpm: nil, fill_missing: true, return_metadata: false) ⇒ Array(Float, Array<Integer>)

Returns estimated tempo and beat frames.

Parameters:

  • y (Numo::SFloat, Array<Float>, nil) (defaults to: nil)
  • sr (Integer) (defaults to: 22_050)
  • onset_envelope (Numo::SFloat, Array<Float>, nil) (defaults to: nil)
  • hop_length (Integer) (defaults to: 512)
  • start_bpm (Float) (defaults to: 120.0)
  • tightness (Integer) (defaults to: 100)

Returns:

  • (Array(Float, Array<Integer>)) —

    estimated tempo and beat frames



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# File 'lib/muze/beat/beat_track.rb', line 15

def beat_track(y: nil, sr: 22_050, onset_envelope: nil, hop_length: 512, start_bpm: 120.0, tightness: 100, min_bpm: 30.0, max_bpm: 240.0, bpm: nil, fill_missing: true, return_metadata: false)
  validate_beat_params!(
    sr:,
    hop_length:,
    start_bpm:,
    tightness:,
    min_bpm:,
    max_bpm:,
    bpm:,
    fill_missing:,
    return_metadata:
  )

  envelope = if onset_envelope
               onset_envelope.is_a?(Numo::NArray) ? onset_envelope.to_a : Array(onset_envelope)
             else
               Muze::Onset.onset_strength(y:, sr:, hop_length:).to_a
             end
  validate_finite_array!(envelope, "onset_envelope")

  if envelope.empty? || envelope.max.to_f <= 1.0e-12
    result = { tempo: nil, beats: [], confidence: 0.0 }
    return return_metadata ? result : [nil, []]
  end

  tempo = bpm || estimate_tempo(envelope, sr:, hop_length:, start_bpm:, min_bpm:, max_bpm:, tightness:)
  beats = track_beats(envelope, tempo:, sr:, hop_length:, tightness:, fill_missing:)
  confidence = beat_confidence(envelope, beats)
  return { tempo:, beats:, confidence: } if return_metadata

  [tempo, beats]
end

.tempo_frequencies(sr: 22_050, hop_length: 512, win_length: 384) ⇒ Object

Raises:



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# File 'lib/muze/beat/beat_track.rb', line 60

def tempo_frequencies(sr: 22_050, hop_length: 512, win_length: 384)
  validate_positive_integer!(sr, "sr")
  validate_positive_integer!(hop_length, "hop_length")
  raise Muze::ParameterError, "win_length must be positive" unless win_length.positive?

  Numo::SFloat.cast(Array.new(win_length) do |lag|
    lag.zero? ? 0.0 : 60.0 * sr / (hop_length * lag)
  end)
end

.tempogram(y: nil, onset_envelope: nil, sr: 22_050, hop_length: 512, win_length: 384, normalize: false) ⇒ Numo::SFloat

Parameters:

  • y (Numo::SFloat, Array<Float>, nil) (defaults to: nil)
  • onset_envelope (Numo::SFloat, Array<Float>, nil) (defaults to: nil)
  • sr (Integer) (defaults to: 22_050)
  • hop_length (Integer) (defaults to: 512)
  • win_length (Integer) (defaults to: 384)

Returns:

  • (Numo::SFloat) 


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# File 'lib/muze/beat/beat_track.rb', line 54

def tempogram(y: nil, onset_envelope: nil, sr: 22_050, hop_length: 512, win_length: 384, normalize: false)
  validate_positive_integer!(sr, "sr")
  validate_positive_integer!(hop_length, "hop_length")
  Muze::Feature.tempogram(y:, onset_envelope:, sr:, hop_length:, win_length:, normalize:)
end