Low complexity cloud-video-mixing using HEVC

Real-time video applications, such as video conferencing and video surveillance systems, typically involve the simultaneous transport of multiple video sources to interested parties that consume the content. It may be desirable to mix these multiple source videos into a single video stream at intermediary nodes in the network. This has the advantage of reduced application and transport complexity on the client device and also makes it possible for devices with a single hardware decoder to consume the content. A typical approach is to apply transcoding operations to the original videos, i.e. the videos are decoded, merged and encoded into a single video stream. This paper proposes an alternative solution to video transcoding, which uses the new video coding standard HEVC and has a much lower processing complexity. We consider how our approach can be realized in real-world applications such as a cloud video mixer. Such systems typically require some degree of dynamics and personalization and we provide some insight into how transport signaling complexities can be addressed.