WebRTC OfferToReceiveAudio error in Firefox

Question

I\'m developing a simple example to test WebRTC, and I\'ve found the following strange behaviour.

When using Chrome, the media constraints are specified as:

Answer 1

In the specs here:

https://developer.mozilla.org/en-US/docs/Web/Guide/API/WebRTC/WebRTC_basics

I see that the constraints should be in the following format:

var constraints = {
    mandatory: {
        OfferToReceiveAudio: true,
        OfferToReceiveVideo: true
    }
};

Chrome only supports that format.

you can refer to this discussion for same issue:

WebRTC - getting 'malformed constraints object' from Chrome but not Firefox