Enhanced quality adaptation strategies for scalable video

Technology today favors tightly compressed, but still extremely high quality video transmitted wireless to mobile devices. Users want to access the video data anytime, anywhere, which sets challenges in the highly-loaded network to provide best possible video quality for the end user. Naturally, in the era of high-definition, users want to experience high quality from their mobile devices even when the channel capacity fluctuates drastically due to congestion. Video adaptation to bandwidth fluctuations plays an important role in modern video transmission in order to maximize the best available video quality, but again to use available bandwidth efficiently. In this paper, we aim to find the best strategy for how the adaptation should be performed, to find sufficient adaptation period and number of layers that maximize the compression efficiency, usage of channel resources and objective quality in video streaming. For the compression, we utilize Scalable Video Coding (SVC), which provides layered video structure and enables video adaptation to bandwidth fluctuations. The results indicate that long adaptation period with complex content encoded for two enhancement layers brings essential channel savings while also maintaining the compression efficiency and objective quality in adequate level.