Video Transcoding to Support Random Access in Scalable Video Coding

In video applications including video broadcasting, interactive TV and IPTV, video streams are transmitted over various networks. In order to fulfill the requirement of video devices to cut-in broadcasting, start playback at a random location and jump to another location, the video service provider has to implement the random access functionality. Furthermore, the random access points can also enable the user devices to refresh the decoding process in error-resilient transmission. In this paper, we propose a novel transocding algorithm to insert random access points in the pre-encoded scalable video streams. Experiments show that the proposed algorithm can get 0.5~2.1dB PSNR gain over full decode and recode (FDR) transcoder and get 0.8~4dB PSNR gain over cascade pixel domain transcoder(CPDT). Simulation results also display that the proposed transcoding algorithm can reduce the computational complexity significant compared with FDR and CPDT method. Key-Words: scalable video coding, transcoding, random access