Content-Based Video Transmission over Wireless Channels

Abstract

This paper describes new schemes for video transmission over wireless channels. Traditionally data was segmented using headers and data type (e.g. motion vectors, low and high frequency DCT coefficients). However, for wireless applications that have very low bandwidths available, a finer granularity of control may be essential. We propose content based approaches for further video segmentation. In particular, frame type, scene changes, and motion based procedures are used to provide finer level of control for data segmentation. We go on to argue that for transport over wireless channels, different video content requires different form of resources to be allocated to it. Joint source/channel coding techniques (particularly class/content/data dependent FEC/ARQ schemes) are used to do resource allocation after initial segmentation. FEC schemes are used to provide class/template dependent error robustness and ARQ techniques give delay control. An experimental simulation platform is used to test the objective (SNR) and subjective effectiveness of proposed algorithms. Based on our initial results from FEC control we argue that introduction of video content into video modeling allows us to define various classes of importance. We believe that by using such techniques we can get better visual quality under the very low bit rates available.