Embedded SNR scalable MPEG-2 video encoder and its associated error resilience decoding procedures

摘要

With the rapid development of digital video, noisy channels such as wireless and satellite are able to transmit digital video for many applications. SNR scalable codec systems provide robust error resilience capability for these channels. This paper presents the design issues of an embedded SNR scalable MPEG-2 video encoder and also its associated error resilience decoding procedures. Two existing cascade quantization designs are reviewed before presenting our further analysis on their performance and possible losses. Based on our observations on the losses of cascade quantizations, a codeword divider is proposed to properly split quantization coefficients into two different layers. The proposed encoder provides improvement on the coding efficiency from that obtained by the cascade quantizers. Error resilience procedures are developed at the decoder side, which fully utilize the properties of a scalable system. Simulation results demonstrate that the proposed codec can achieve superior quality in decoded pictures, regardless of bit-rate ratio between the layers or during error bursts. Furthermore, since only one quantization device is needed, this encoder relatively reduces hardware complexity.