Optimal rate control for video transmission over VBR channels based on a hybrid MMAX/MMSE criterion

In this paper, we consider the problem of rate control for video transmission over variable bit rate (VBR) channels. We focus on finding off-line optimal rate control for VBR transmission with a token bucket policing function. To ensure a maximum minimum quality is obtained over all data units, we introduce a minimum maximum distortion (MMAX) criterion in this channel-constrained problem. We show that, due to the channel constraints, a MMAX solution leads to a relatively low average distortion, because the total rate budget is not completely utilized. Therefore, after finding a MMAX solution, an additional minimization of average distortion (MMAX+) criterion is proposed to increase overall quality of the data sequence by using remaining resources. The proposed algorithms lead to an increase in average quality with respect to the MMAX solution, while providing a much more constant quality than MMSE solutions. Moreover we show how the MMAX+ approach can be implemented with low complexity.