A Hybrid Encoder/Decoder Rate Control for Wyner-Ziv Video Coding with a Feedback Channel

This paper describes a hybrid coder/decoder rate control for a Wyner-Ziv video coding scheme with a feedback channel. The approach is first based on a method to estimate at the encoder the minimum rate required for the Slepian-Wolf (SW) encoded data. This estimation makes use only of the Lapacian correlation model. The decoder then estimates the bit error rate (BER) for each decoded bit plane from likelihood ratios computed at the output of the SW decoder. The robustness of the BER estimation is further improved by the use of an error detection mechanism based on a cyclic redundancy checksum. Experimental results show that rate-distortion performances are comparable to those which would be obtained by computing the Hamming distance between the original and the decoded data. In addition the hybrid coder/decoder rate control reduces the decoding complexity as well as the usage of the return channel.