AudioIntervals

AudioIntervals[audio,crit]

returns intervals of audio for which the criterion crit is satisfied.

AudioIntervals[audio,crit,mindur]

returns only intervals larger than the given duration mindur.

Details and Options

  • AudioIntervals can be used to detect parts of an audio signal that have specific characteristics.
  • The criteria function crit can take #prop arguments, and uses the local property "prop" for each partition selection.
  • The following properties can be used for interval selections.
  • Basic histogram properties:
  • "MaxAbs"maximum absolute value
    "Max"maximum value
    "StandardDeviation"standard deviation of values
  • Intensity properties:
  • "Power"mean of the squared values
    "RMSAmplitude"root mean square of the values
    "Loudness"the loudness using Steven's power law
    "LoudnessEBU"the loudness according to EBU momentary standard
  • Time domain properties:
  • "CrestFactor"maximum divided by the root mean square
    "Entropy"entropy of values
    "PeakToAveragePowerRatio"maximum power divided by the average power
    "ZeroCrossingRate"rate of zero crossings
    "ZeroCrossings"number of zero crossings
  • Frequency domain properties:
  • "FundamentalFrequency"estimated fundamental frequency
    "ModifiedKullbackLeibler"modified KullbackLeibler distance between spectra of consecutive partitions
    "SpectralCentroid"centroid of the power spectrum
    "SpectralCrest"maximum divided by the mean of the power spectrum
    "SpectralFlatness"geometric mean divided by the mean of the power spectrum
    "SpectralKurtosis"kurtosis of the magnitude spectrum
    "SpectralRollOff"frequency below which most of the energy is concentrated
    "SpectralSkewness"skewness of the magnitude spectrum
    "SpectralSlope"estimated slope of the magnitude spectrum
    "SpectralSpread"measure of the bandwidth of the power spectrum
  • The minimum duration mindur can be a non-negative real number in seconds, a time quantity, or a samples quantity.
  • The following options can be given:
  • AlignmentAutomaticalignment of the time stamps with partitions
    FourierParameters{-1,1}Fourier parameters
    PartitionGranularityAutomaticaudio partitioning specification
  • By default, measurements are returned at the center of each partition. Using the Alignment option, measurements can be returned at the beginning (Left) or end (Right) of each partition.

Examples

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Basic Examples  (1)

Compute silent intervals of audio:

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Find intervals where the RMS amplitude is less than 0.01:

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Visualize silent intervals:

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Find only intervals longer than 0.2 seconds:

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Scope  (1)

Options  (2)

Applications  (2)

See Also

AudioLocalMeasurements  AudioMeasurements  AudioLoudness  AudioDelete  AudioTrim  Duration  AudioSplit

Introduced in 2016
(11.0)
| Updated in 2017
(11.1)