Enabling Temporal Bit Rate Adaptation in Encrypted Video Streams
Matthias Krause, Marek Burza · 2010
In practice, video streaming over wireless network through home gateways requires bandwidth adaptation methods to deal with the fluctuation bandwidth the network. A popular method to compensate for temporary insufficient data throughput is dropping of B-frames. However, this method cannot be applied for encrypted commercial content, because frame types cannot be identified due to encryption of frame headers. Dropping I-frames or P-frames is not an option, because the video quality would drop dramatically. We developed a new approach using a sliding window to estimate the types of frames in an encrypted video stream. We validate the approach with probability calculations and extensive testing to demonstrate feasibility. Based on a large set of video sequences, our proposed algorithm drops the right frames in 99.99% of the cases.