Soft decoding for robust video transmission

Often compressed video can be separated into high- and low-priority data on the basis of the contribution of the data to the quality of the reconstructed video. There has been significant interest in unequal error protection (UEP) for robust video transmission. Traditional UEP methods protect the high-priority data more highly than the low-priority data, that is, they employ less powerful channel codes on the low-priority data. In this work a method of utilizing soft decoding of variable-length source codes for unequal error protection is presented. No channel coding is used on the high-priority data, instead, soft-decision decoding is employed to recover from channel errors. Results are shown using an MPEG-4 codec. These results are subjectively comparable to those obtained by using a traditional UEP method