Examining Memory in Reconstruction Distortion: Dropping Additional Packets to Improve Video Quality

The source coding process and the packet loss process create certain dependencies between encoded video units in terms of the reconstruction distortion of the video signal at the receiver in case of transmission over packet erasure channels. In this paper, we examine the importance of this "distortion memory" via a specific class of memory-based models denoted Distortion Chains that are used for predicting the distortion of the reconstructed video signal in case of missing multiple packets at the receiver. We show that taking into account even the smallest amount of memory that is possible can yield substantial gains in terms of prediction accuracy and packet selection (packet dropping) performance. An additional and rather surprising result of our study is the fact that in certain situations dropping an additional video packet (which could otherwise be delivered) can actually improve the quality of the reconstructed video