This paper proposes a novel robust framework for scalable video over Internet. The main contribute of our work is that a simplified rate-distortion theory is specially developed for scalable bit-stream over the network and the corresponding bit allocation is presented to determine the sets of the channel rate for each video layer. Compared with the traditional iterative optimal bit allocation with complexity O(nL) time, simulations show that our scheme achieves high quality video transmission with much less complexity O(L x n) time, only no more than 0.2dB under different network conditions (different bandwidth and different packet loss case). Besides, our error control scheme can be naturally combined with congestion control and error resilient techniques to enhance the performance of the overall system.
Selective enhancement mechanism of Fine-Granular-Scalability (FGS) In MPEG-4 is able to enhance specific objects under bandwidth variation. A novel technique for self-adaptive enhancement of interested regions based on Motion Vectors (MVs) of the base layer is proposed, which is suitable for those video sequences having still background and what we are interested in is only the moving objects in the scene, such as news broadcasting, video surveillance, Internet education, etc. Motion vectors generated during base layer encoding are obtained and analyzed. A Gaussian model is introduced to describe non-moving macroblocks which may have non-zero MVs caused by random noise or luminance variation. MVs of these macroblocks are set to zero to prevent them from being enhanced. A segmentation algorithm, region growth, based on MV values is exploited to separate foreground from background. Post-process is needed to reduce the influence of burst noise so that only the interested moving regions are left. Applying the result in selective enhancement during enhancement layer encoding can significantly improves the visual quality of interested regions within an aforementioned video transmitted at different bit-rate in our experiments.