基于LDPC的码率自适应分布式视频编码
摘 要
为了在分布式视频编码(DVC)中取得更好的压缩性能,将校验节点的合并和分裂进行有机结合,提出了一种码率自适应LDPC(RALDPC)编码新方法。该方法首先基于PEG算法构造高压缩比LDPC码字;然后由行均匀分裂得到低压缩比码字;最后通过合并或分裂校验矩阵对应的行来适度调整码率。为保证码字性能,还提出了校验节点合并的3个限制条件,并基于RALDPC提出了一种码率自适应DVC编码方案。实验结果表明,与当前基于Turbo码的DVC方案相比,在原信息和边信息高度或中度相关时,编码性能提高了0.1~0.7dB。
关键词
Rate adaptive distributed video coding based on LDPC
Yang Chun Ling1, Xia Hongtao1,2, ZHANG Xingshao1(1.School of Electronic and Information Engineering,South China University of Technology,Guangzhou 510640;2.China Unicom Co.,Ltd.Guangzhou Branch,Guangzhou 510630) Abstract
In order to achieve better rate distortion (RD) performance in distributed video coding (DVC), a new rateadaptive low density parity check (RALDPC) coding algorithm is proposed. Firstly, a high compression ratio code is constructed based on progressive edge-growth (PEG) algorithm. Then low compression ratio codes are obtained using row splitting algorithm. The rate can be well adjusted by merging and splitting the parity-check matrix rows. And three restriction conditions for merging check nodes are proposed in order to obtain good performance codes. Based on the RALDPC, a rate adaptive DVC algorithm is proposed, which can achieve better RD performance about 0.1~0.7dB compared to DVC algorithm based on the popular Turbo codes, when the correlation between the original and side information is medium or high.
Keywords
distributed video coding(DVC) low density parity check (LDPC) rate-adaptive progressive edge-growth(PEG) algorithm syndrome
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