Beat Estimation On The Beat

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Beat Estimation On The Beat

• Kristoffer Jensen
• And
• Tue Haste Andersen

WSPAA 03
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Outline

• Intruduction
• System
• Audio feature selection
• Beat estimation
• Beat location
• Conclutions

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Intruduction

• This work develops a system to find the time
  between beats and the location of the beat from a
  sampled waveform in real-time
• A feature extracted from the waveform is used to
  identify note onsets. The estimated note onsets
  are used as input to a beat induction algorithm,
  where the most probable beat intervals are found.

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Intruduction

• Some onset positions may correspond to the
  position of a beat while other onsets fall off
  beat. By detecting the onsets in the acoustic
  signal, and using this as input to a beat
  induction model, the beat is estimated.

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System
Couple the beat induction histogram with the beat
location estimation for finding the beat location
and Interval
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Audio Feature Selection

• The basis of the beat estimation is one audio
  feature respond to the transient note onset
• Amplitude, spectral centroid, high frequency
  energy, high frequency content, spectral
  irregularity, spectral flux and running entrpoy

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Audio Feature Selection
To identify a note onset from a given feature a
peak detection algorithm is needed Generally the
missed ratio rises when the spurious ratio fall
and vice-verse So its hard to select the
optimum feature
High frequency content (HFC)
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Beat Estimation

• Beat induction system for
• - cleaning up spurious beats
• - introducing missing beats
• Beat induction histogram is a dynamic model of
  the beat intervals that permits the
  identification of the beat intervals from noisy
  feature

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Beat Estimation
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Beat Location

• Problem still many sputious and systematic peaks
  in the HFC in between the beat
• The beat interval may be known, but the absolute
  position of the beat is unknown

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Beat Location
Some potential problem The off beat peaks are as
strong as the on beat peaks Use of a
multiplication threshold
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Conclusions

• Presents a complete system for the estimation of
  beat interval including the estimation of the
  exact location of the beat