WebRTC OfferToReceiveAudio error in Firefox
Solution 1:
The right format (by now) is:
offerOptions = {'offerToReceiveAudio':true,'offerToReceiveVideo':true};
as this is the new spec format and is supported by both Chrome and Firefox.
Take special care to note the lower-case 'o's, as this did change and threw more than a few people. Hopefully you got it working by now.
Also note that these are no longer "constraints", just "options". Simpler.