Minimum Variance Optimal Rate Allocation for Multiplexed H.264/AVC Bitstreams

Consider the problem of transmitting multiple video streams to fulfill a constant bandwidth constraint. The available bit budget needs to be distributed across the sequences in order to meet some optimality criteria. For example, one might want to minimize the average distortion or, alternatively, minimize the distortion variance, in order to keep almost constant quality among the encoded sequences. By working in the -domain, we propose a low-delay rate allocation scheme that, at each time instant, provides a closed form solution for either the aforementioned problems. We show that minimizing the distortion variance instead of the average distortion leads, for each of the multiplexed sequences, to a coding penalty less than 0.5 dB, in terms of average PSNR. In addition, our analysis provides an explicit relationship between model parameters and this loss. In order to smooth the distortion also along time, we accommodate a shared encoder buffer to compensate for rate fluctuations. Altho...

• Type: Journal
• Year: 2008
• Where: TIP
• Authors: Marco Tagliasacchi, Giuseppe Valenzise, Stefano Tubaro
• Keywords: Average Distortion, Distortion, Distortion Variance, TIP 2008