An adaptation mechanism for robust OTT video transmission

“Over the top” (OTT) has become an increasingly popular form of delivery for voice and video communications. Ubiquitous OTT communications, pioneered by Skype, have, with the recent release of WebRTC, become a commodity readily available for various applications, without a need for extra installations. Still, in spite of such progress, media communications remain challenging as user expectations are keeping ahead of technology progress and portable devices are becoming the norm. In practical terms, this means that media flows must constantly adapt to varying network conditions to try to -reliably!- offer the best experience to the users. We present in this paper a sender-side adaptation algorithm for video flows which trades off redundancy and throughput to maximize quality while minimizing the likelihood of loss, thus preserving service continuity. By exploiting standard FEC mechanisms at different levels of redundancy while controlling the quality of media delivered, we create a discrete parameter space which the algorithm exploits based on quality feedback. We study the performance of this algorithm in a number of reference test cases and discuss how it improves on earlier and related proposals.