We describe a source and channel coding algorithm suitable for video messaging over wireless networks. The research platform is based on ITU-T H.263 video coding, Reed Solomon channel coding, data interleaving and a wireless network provided by Lucent's WaveLAN. We consider the special characteristics of one-way video messaging, and propose rate control, unequal error protection and error concealment algorithms with features for object-oriented quality enhancement. These features consist of: (1) object-oriented bit allocation based on the segmentation of video into objects of interest, (2) unequal channel error protection by object-oriented data partitioning, and (3) object-oriented error concealment using the locations and motion vectors of object. Based on experiments with head and shoulders scenes, the subjective quality and error resilience of decoded video are seen to increase significantly. Simulation results show that the proposed algorithm is effective at high packet loss rates and with clustered packet losses.
['Seong Hwan Jang', 'Nikil Jayant']
Object-oriented source and channel coding for video messaging applications over wireless networks