Error concealment for robust arithmetic decoding in mobile radio environments

Arithmetic coding is a technique for achieving maximum compression in video codecs by exploiting any residual correlation exhibited by parameter sets delivered by the source coding algorithm. This inherent characteristic implies poor error resilience, specially in the interesting case of low bit-rate video transmission over mobile networks. In this paper, a modified arithmetic decoding algorithm based on the adaptation of the underlying model probabilities according to reliability information delivered by a soft output channel decoder is presented. Furthermore, additional techniques for enhancement of the concatenated channel-source decoding scheme based on spatial linear prediction in conjunction with reliability estimates of the received video frame are presented. The performance of the addressed error concealment techniques is evaluated and analyzed through simulations in the case of an error protected video transmission over a Gaussian and mobile Rayleigh fading channel.