Rate-distortion optimized bit allocation for error resilient video transcoding
A key issue in video transcoding for transmission in an error-prone environment is to balance the rate used for the video source with bits allocated for error resilience such that the end-to-end distortion is minimized under the given rate constraint and channel condition. The approach presented in this paper differs from previous works by accounting for the inter-frame dependence in both video source requantization and error propagation of motion compensated video. Based on the rate-distortion models developed in this paper, an optimal group-of-picture based bit allocation scheme is proposed. We also propose a sub-optimal scheme that is suitable for a real-time implementation. Both the optimal and sub-optimal scheme achieves better PSNR performances than the fixed heuristic bit allocation scheme.