关键词: P2P流媒体，分层编码，多描述编码，分层多描述编码，像素空间分解

Abstract: Heterogeneity and transmission reliability are two of the major problems in network video communications.For video coding, layered coding is used to solve the problem of network heterogeneity and multi-description coding is an effective way to address the transmission reliability issue,furthermore layered multi description coding is a combination of both. Based on layered coding technology, we proposed a layered multi-description coding method based on pixel space decomposition. We presented corresponding sub-layer combination algorithm and pixel evaluation algorithm which can enhance the video quality for users. Moreover, By analyzing on the relationship between quantitative value and evaluation error of pixels, we established a mathematical model for layered multi-description decoding. Experimental results show that the proposed scheme performs better in heterogeneous P2P networks and gives a better solution to transmission reliability problems.

Key words: P2P stream media, Layered coding, Multi description coding, Layered multi-description coding, Pixel space decomposition