Adaptive streaming technologies like Adobe’s Dynamic Streaming, Microsoft’s Smooth Streaming, and Apple’s HTTP Live Streaming, use multiple encoded files to deliver the optimal viewing experience to video consumers watching on a range of devices, from mobile phone to workstation, via a range of connections, from FIOS to cellular. Though there are differences in implementation, all adaptive technologies switch streams based upon heuristics like CPU utilization or buffer size. That is, if the player detects that buffer levels are too low, it may choose a lower data rate stream to avoid running out of data. If CPU utilization gets too high and frames start dropping, it may request a lower resolution file that’s easier to decode.
While most of the technology that enables stream switching is lodged in the player or streaming server, there’s lots to do on the encoding side to produce streams that switch smoothly. In this article, I’ll outline the key differences between producing for single stream delivery and producing for adaptive streaming.
Via Nicolas Weil