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onsets​

onsets(
    @alpha 0.1
    @delay 5
    @framerate 86.1328
    @silencethreshold 0.02
) -> llll

Generates an audio descriptor to compute the onset positions in a buffer.

The resulting buffer will be updated with the following keys:

  • onsets
info

onsets is a mirror implementation of the same algorithm in the Essentia library. For more details on the algorithm, please check the Essentia Algorithms reference.

Arguments​

  • @alpha [float]: Proportion of the mean included to reject smaller peaks—filters very short onsets. (default: 0.1).
  • @delay [int]: Number of frames used to compute the threshold—size of short-onset filter. (default: 5).
  • @framerate [float]: Frames per second. (default: 86.1328).
  • @silencethreshold [float]: Threshold for silence. (default: 0.02).

Output​

Onsets descriptor [llll]

Usage​

onsets is meant to be used with the analyze function:

$buffer = importaudio('singing.wav'); ## input buffer
$descr = onsets(); ## generate onsets audio descriptor
$buffer.view('before analysis');
$buffer = $buffer.analyze($descr); ## apply analysis
$buffer.view('after analysis')