Audio descriptors

Compute descriptors

Before use this feature, you need to import audio or movie file.

  1. Select Compute > Audio Descriptors.
  2. Select a file.
  3. [Optional] Edit title of file.
  4. Mix channels before computing or compute descriptors on each channel in different series.
  5. Change FFT parameters.
  6. Select one or more descriptors and edit parameters.
  7. Select Compute.

You can use descriptor files in temporal visualization or timeline

Types of descriptors

Amplitude RMS

Compute root mean square amplitude of signal (No FFT parameters is needed).

Fundamental frequency estimation

Compute f0 for each frame. This command uses YIN algorithm and is adapted to solo voice or monophonic instrument.

Peak frequency

Compute peak of frequency for each frame.

Spectral centroid

Compute the centre of gravity of FFT.

Spectral crest

Ratio between the maximum value and the arithmetic mean of the FFT.

Spectral decrease

Average spectral slope of the FFT.

Spectral flatness

Ratio between the geometric mean and the arithmetic mean.

Spectral flux

Temporal variation of the logarithmically-scaled rate-map across adjacent frames.

Spectral rolloff

Frequency in below which the threshold of the total spectral energy is concentrated.

Spectral standard deviation

Square root of the spectral variance.

Spectral variance

Measures how much the frequencies can deviate from the centre of gravity (spectral centroid).

Zero crossing rate

Rate at which zero crossings occur (No FFT parameters is needed).