Spec doesn’t say what happens on reuse

[jan-ivar]

What should happen if a transform is reused? E.g.

const pc = new RTCPeerConnection();
const senderA = pc.addTransceiver("audio");
const senderB = pc.addTransceiver("video");
const transform = new RTCRtpScriptTransform(worker, {});
senderA.transform = senderB.transform = transform;

The spec says RTCRtpScriptTransform and RTCRtpScriptTransformer are 1←→1, so they can’t be reused without single-filing A and B processing through the single pipe, which seems undesirable.

Offline feedback from @youennf suggests single-use was intended?

That said, it might be useful to switch between transforms on the same sender, or turning transformation on/off e.g.

tickmark.onclick = () => { senderA.transform = tickmark.checked? transform : null; }

I propose we throw if a transform was ever assigned to a different sender or receiver.