Estimation of the utilities of the NAL units in H.264/AVC scalable video bitstreams

In our previous work [1, 2], we proposed a framework to provide optimized unequal error protection (UEP) with Reed-Solomon codes to the H.264/AVC scalable video bitstreams to get robust video streaming for uni-/multicast applications. In that framework, we need to measure the real utilities of the network abstraction layer (NAL) units in a separate process before the transmission of the bitstream. This process requires, however, multiple decoding processes of the whole bitstream, which makes the framework not directly applicable to a live streaming system, where the video content is captured and must be transmitted within a constrained delay. In this work, we present a simple but very effective algorithm to estimate the utilities of the NAL units on the enhancement layer. With the estimation algorithm, we don't need additional decoding processes, except those with the complete base layer and enhancement layer, which are integrated in the encoder. We performed intensive tests with the estimation algorithm for different sequences in the UEP framework. Our simulation results show that good UEP performance can be achieved with the estimated utilities. The loss of performance using the estimated utilities against the real utilities is very low, if the estimation period is appropriately selected.