Backward error concealment of redundantly coded video

Error concealment at the video decoder is to recover erroneous picture region based on correctly decoded region in the same frame or the neighboring frames. However, error concealment cannot give satisfactory result in some cases, e.g. when a whole frame is lost. In this paper, we propose a novel backward error concealment method. While the existing temporal error concealment methods recover an erroneous frame by using its reference frame, the proposed method uses a refreshed future frame to recover the previous corrupted reference frame. This is based on the observation that a future frame can be recovered before its reference frame when some error resilience tools such as intra refresh or redundant picture are used. The advantage of the proposed method is that it can recover most pixels in the corrupted reference frame by inverse motion compensation without any error, since typically the refreshed future frame has both MVs and the residues. In the experiments, the proposed method achieves up to 1.0 dB gain over the state-of-the-art temporal error concealment method.