A unified framework for spectral domain prediction and end-to-end distortion estimation in scalable video coding
A novel scalable coding approach is proposed for video transmission over lossy networks, which builds on two estimation-theoretic (ET) paradigms previously developed by our group: (1) an ET approach to enhancement layer prediction in scalable video coding (ET-SVC) that optimally combines all available information from both the current base layer and prior enhancement layer frames, and (2) the spectral coefficient-wise optimal recursive estimate (SCORE) of end-to-end distortion. SCORE provides the encoder with an estimate of distortion per decoder-reconstructed transform coefficient, accounting for the effects of quantization, concealment, packet loss and error propagation via the prediction loop. The current work significantly extends the scope of SCORE to encompass the setting of ET-SVC, whose prediction involves non-linear operations. This advance enables optimization of ET-SVC systems for transmission over lossy networks, thereby combining optimal prediction with optimal mode decisions at the enhancement layer. Experiments first demonstrate the estimation accuracy of SCORE in the settings of the ET-SVC coder. They then show considerable gains when SCORE is incorporated into ET-SVC to optimize encoding decisions under a wide range of packet loss and bit rates.