It uses WebRTC for the video, but the audio latency of WebRTC is too large and uncontrollable.
As stated in the post, the audio uses a custom C++ UDP solution. As far as I know it's the first video calling app with very low latency audio.
As stated in the post, the audio uses a custom C++ UDP solution. As far as I know it's the first video calling app with very low latency audio.