SVC

SVC stands for Scalable Video Coding.

SVC is a technique that allows encoding a video stream once in multiple layers. The layers in SVC are akin to the layers in an onion – they can be “pealed off” while maintaining the video, reducing its quality with the reduction of each layer.

This mechanism is useful when:

1. Wanting to employ FEC to video, as we can protect the stream by adding redundant data to some of the layers only
2. Wanting to send the video data to multiple participants, where we can send different layers to different participants based on their capabilities. This assists when using routing mechanisms for conferencing

SVC is added as part of the VP9 codec implementation in WebRTC.

Make sure you also read about simulcast.