1388525 - Once a call to audioParam.setTargetAtTime is called, then all changes to the audioParam's value must be made with a call to setValueAtTime() or another automation method. All direct assignments to audioParam.value will fail silently.

Status: RESOLVED DUPLICATE of bug 1308435

(Core :: Web Audio, defect, P1)

Description

[Rich Caloggero]

Attachment: webaudio-bug.md

User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:55.0) Gecko/20100101 Firefox/55.0
Build ID: 20170803103124

Steps to reproduce:


let audio = new AudioContext ();
test (audio);

function test (c) {
let o = c.createOscillator();

o.frequency.value = 220;

o.connect(c.destination);

o.start();
o.frequency.setTargetAtTime (440, c.currentTime, .5);
setTimeout (() => {
// this fails with no errir
o.frequency.value = 100.0;

// this succeeds
//o.frequency.setValueAtTime( 100.0, c.currentTime); 
}, 1000 * 1.5);
o.stop (c.currentTime+2.0);



Actual results:

// observed behavior: ramps smoothly from 220 to 440, but fails to drop to 100




Expected results:

// should ramp frequency from 220 to 440, then suddenly drop to 100 hz.

Comment 1

[Back Aug 24 [:jib]]

Paul, can you confirm?

Comment 2

[Paul Adenot (:padenot)]

Yes, this is what the spec used to say. We've changed it. I have written half the patch to implement the new behavior and a couple other goodies, like optimizations, but haven't had time to work on it.