Support of Opus audio for WebRTC streaming

We have a few Mobotix IP cameras and were looking for a way to stream them to HTML5 tag with minimal latency. So we explored WebRTC options and tested Webcall Server and Unreal Media Server, and found the latency to be stable 0.5 sec, which is good for us.

However, the audio needs to be transcoded from AAC to Opus in software, hence a feature request: support of Opus audio on-board.