Let’s add FEC and DTx to Opus!

[Luke Escude]

Adding the opus codec was an excellent feature, but now time to take it to the next level, with FEC and DTx.

What is FEC?

Glad you asked! FEC, or Forward Error Correction, allows the RTP (audio) to contain a partial “backup” of previously sent audio. With this, in the event of packet loss on the network, the phone (decoder) is able to reconstruct any lost audio.

With this feature, a phone call could withstand up to 30% packet loss and you’d hear the other person clear as a bell.

DTx saves bandwidth by sending null audio packets during silence.