stft

Short time Fourier transform

npm install stft
1 downloads in the last week
11 downloads in the last month

stft

A streaming-ish short time Fourier transform.

Example

var shortTimeFT = require("stft")


function onFreq(re, im) {
  //Frequency stuff.  Process it here
  istft(re, im)
}

function onTime(v) {
  //Got data, emit it here
  console.log("out frame:", v)
}

var stft = shortTimeFT(1, 1024, onFreq)
var istft = shortTimeFT(-1, 1024, onTime)

//Feed stuff into signal
stft(new Float32Array([1, 0, 0, 0, ... ])

Install

npm install stft

require("stft")(direction, frame_size, ondata[, options])

Creates a function for processing a signal with a short time Fourier transform.

  • direction is a flag that determines whether the stft is forward or inverse
  • frame_size is the size of a frame for the stft
  • ondata is a callback that gets fired whenever data is ready to be processed
  • options is an optional object that takes the following parameters

    • options.hop_size the amount of samples between stft hops
    • options.window_func a windowing function, which takes a parameter from [0,1] and returns a weight

Returns A function that can be called with a frame (either real or complex) that adds a chunk of data to the stft queue

require("stft").stft(frame_size, ondata[, options])

Short cut for require("stft")(1, frame_size, ondata, options)

require("stft").istft(frame_size, ondata[, options])

Short cut for require("stft")(-1, frame_size, ondata, options)

Credits

(c) 2013 Mikola Lysenko. MIT License

npm loves you