Robust FMO algorithm and adaptive redundant slice allocation for wireless video transmission

Abstract

Visual quality of compressed video may suffer great degradation when transmitted over lossy wireless networks. Flexible macro-block ordering (FMO) is a new error resilient tool adopted by H.264/AVC. It has a good performance of error resilience by changing the coding order of macro-blocks in the frame. redundant slice (RS) is another tool which adds redundant copy of slices into the stream to take precautions against packet loss. However, we shouldn't only care about peak signal to noise ratio (PSNR) of the video; the robustness of video streams to burst packet loss of wireless channel is also worth considering. In applications, such as real-time video transmission services, degradation of video quality may be tolerable, but collapse of decoder due to burst packet loss will greatly lower user's quality of experience. This paper proposes a robust FMO (RFMO) algorithm which takes gradient feature of frames into consideration to enhance robustness of video streams, and the adaptive RS allocation (ARSA) helps to increase the PSNR with only a little increase in bit rate. Experiment results show that the RFMO algorithm can significantly reduce the collapse times of decoder with invisible decrease in visual quality, and the ARSA can still guarantee a high PSNR in the case of high packet loss rate.