Error Detection and Correction in H.263 coded video over wireless network (original) (raw)

Due to the use of variable length code (VLC), a single bit error in the DCT-based coded bitstream such as H.263 may propagate up to the end of the group of block (GOB) or slice. In this paper, we propose an iterative error detection and correction algorithm for the slice mode of the H.263 bitstreams. The visibly erroneous macroblocks (MB) in the decoded frames are detected by checking a set of error detection conditions derived from the redundant information (such as neighbouring MB and inner DCT block similarity measure) inherent within the frame. An iterative re-decoding based correction algorithm is then applied to the erroneous slices. The proposed technique limits the error into a few MBs only, which can easily be concealed by any error concealment technique. The simulation results demonstrate that our scheme can recover the corrupted frames under the bit error rates up to 0.5% over binary symmetric channel (BSC), and improve the concealed picture quality by up to 8 dB over the conventional methods.