audio - javascript pitch shift with time stretch

Question

I'm a beginner learning javascript. I've got various projects in mind with an interactive page on my site related to microtonal frequencies and planetary frequencies. I need to be able to play my audio sample .wav file in a loop but have the audio sample timestretched with a corresponding change in pitch.

I tried myAudio.playbackRate = 0.5; which plays the audio 0.5 slower but keeps pitch same. I researched and found something. But how do i set preservesPitch to false or true? And this only works in 'Google Chrome' I think, so other program i found is here :
https://github.com/janesconference/KievII/blob/master/dsp/pitchshift.js

Can't seem to get it working, i don't know how i am supposed to modify it, where do i paste my Audio .wav file URL in the program ? Any other tips related to this would be much appreciated. Thanks in advance for your time and help.

Answer 1

you can set the mozPreservesPitch property to false to change the pitch of an element or soundfile with Firefox. webkitPreservesPitch is supposed to work with webkit browsers but note that "this API is not yet standardized" ...

https://developer.mozilla.org/en-US/docs/Web/API/HTMLMediaElement

This worked for me:

var soundPlayer = new Audio();

function playLowerNote() {
    soundPlayer.src = "piano.mp3";
    soundPlayer.mozPreservesPitch = false;
    soundPlayer.playbackRate = 0.5;
    soundPlayer.play();
}

playLowerNote();

Still looking myself for a better way to loop.