An error detection and recovery algorithm for compressed video signal using source level redundancy

The motion compensation-discrete cosine transform (MC-DCT) coding is an eff icient compression technique for digital video sequence. However, the compr essed video signal is vulnerable to transmission errors over noisy channel. In this paper, we propose a robust video transmission algorithm, which pro tects the compressed video signal by inserting redundant information at the source level. The proposed algorithm encodes every lth frame in the semi-i ntra frame (S-frame) mode, in which the redundant parity-check DC coefficie nts (PDC's) are systematically inserted into the compressed bitstream. Then , the decoder is capable of recovering very severe transmission errors, suc h as loss of an entire frame, in addition to detecting the errors effective ly without requesting any information from external devices. The proposed a lgorithm is implemented based on the H.263 coder, and tested intensively in realistic error prone environment. It is shown that the proposed algorithm provides much better objective and subjective performances than the conven tional H.263 coder in the error prone environment.