In video coding, there are inter-frame dependencies due to motion-compensated prediction. The achievable rate distortion performance of an inter-coded frame depends on the coding decisions made during the encoding of its reference frames. Typically, in the encoding of a reference frame, these dependencies are either not considered at all or only via some rough heuristic.In this thesis, a multi-frame transform coefficient optimization method for H.265/ HEVC is developed and studied. The inter-frame dependencies are described using a linear signal model. Based on this model, the optimization problem is cast in the form of an 1 -regularized least squares problem. For solving this problem, an optimization algorithm is developed, which is applicable to H.265/HEVC without imposing excessive demands in terms of computational complexity and memory requirements. A simple functional relationship between the regularization parameter and the quantization paramter is empirically found. The accuracy of the linear signal model is studied, the bit rate savings due to the proposed method are evaluated, and its complexity is assessed. Finally, an extension of the method for spatially scalable video coding using SVC, the scalable extension of H.264/AVC, is presented.iii
ZusammenfassungBei der Codierung von Videosignalen ergeben sich aufgrund der bewegungskompensierten Prädiktion Abhängigkeiten zwischen den einzelnen Frames. Die erzielbare Rate-Distortion-Performance eines inter-codierten Frames hängt dadurch von den Codierentscheidungen ab, die bei der Codierung seiner Referenzbilder getroffen wurden. Typischerweise werden diese Abhängigkeiten bei der Codierung eines Referenzbildes entweder gar nicht beachtet oder aber nur mittels einer groben Heuristik.