Visual evaluation, scaling and transport of secure videos

Due to the pervasive access to broad band internet at home and on mobile devices Video-onDemand (VoD) and video streaming become more and more popular. Consumers of VoD want to use such systems without locational restrictions, as is embodied in the idea of “ubiquitous computing”, and on any device ranging from cell phones via 3G connection to home cinema system. This requires that VoD providers store videos in various resolutions and qualities, adapted to the screen resolution and connection speed of consumer systems. This in turn leads to an increase in storage and consequently an increased cost for providers. However, there is a solution for this kind of problem, the Universal Multimedia Access (UMA). UMA means a video is encoded in a way which allows the adaptation to consumer requirements from a single source video. This leads not only to a reduction in required storage but also allows to adapt the VoD system to target platforms which were not originally taken into account. The drawback of such a system is the computational cost required to adapt the video. Fortunately, this computational cost can be shifted away from the original server since modern network technologies allow adaptation in the network Just-in-Time (JIT), i.e., at the last possible moment in the network. This can be done by using multimedia aware network elements (MANE), and can theoretically reduce the actual transfer rate at the original server by using multicast and performing the adaptation JIT at the appropriate point in the network. Wavelet based video codecs are inherently scalable and thus fit this application scenario perfectly. Additionally, the performance in terms of quality is the same as for current state of the art, non wavelet based, video codecs. The Motion Compensated Embedded Zero Bit Codec (MCEZBC) is a state of the art wavelet based video codec, and thus meets all the requirements for its use for UMA. To use a wavelet based codec for UMA seems deceptively easy. However, the direct application is prevented by MANEs, network protocols and standards which are designed in regard to the current standardised codec, i.e., H.264. Additionally, providers of VoD want a secure end-to-end communication with their customers to prevent piracy. This is in conflict with the idea to use JIT scaling in the network since full encryption would also prevent MANEs from accessing the video for adaptation. In this cumulative thesis we will thus deal with the following problems: We have to ensure that MC-EZBC based video codecs can be transported via existing technology; We have to develop encryption methods for secure end-to-end connection which allow JIT adaptation in the network; and we have to develop methods to ensure and evaluate these encryption methods.