Significant Macroblock-based Error Resilient Video Coding

With the rapid development of video coding techniques, especially after the occurrence of MPEG-4 and H.264/AVC, video compression rate has been improved a lot. On the other hand, the underlying networks (e.g. Internet, wireless, and etc.) have also been improved to support video transmitting. So more and more video applications over network come into use, e.g. Video on Demand, video conferencing, and video surveillance.However, the extremely high demand of video data still exceeds the ability of underlying Internet/wireless networks. Since most of the video applications don't allow too much delay, packets that carry video data often suffer from loss. The compressed video data are very sensitive to errors due to residues reduction. With no error control schemes, the decoded video often suffers from large quality degradation and causes visual artifacts. To reduce the effect of errors, a large number of error control schemes are introduced both in video encoder and decoder.Based on the study of current error control schemes, we devise a novel error resilient video coding scheme. This scheme is called significant macroblock (SMB) protection-based error resilient video coding. It is a UEP-like method for inter macroblock protection. Statistical methods are used to establish an offline Inter-block mode, MVD and SAD-based SMB determination model. Error concealment (EC) function at decoder side is taken into consideration in advance and several parameters for further significant degree (SD) evaluation for an MB are generated. During encoding, we build an SD table for each frame based on the parameters and pick up those MBs with the largest SD values as SMBs. Few additional computations are induced in SMB determination, thus make our scheme practical in real time scenarios. Simulations show that this scheme has an acceptable SMB determination accuracy and the corresponding protections can prevent errors effectively.