A -Domain Based Joint Optimization of Source-Channel Video Coding

Abstract- With the rapid growth of wireless multimedia communications during the last decade, there has been an increasing interest in joint source-channel coding schemes due to the intrinsic unreliability of radio channels. In fact, the high percentage of lost packets, as well as the intensive use of prediction to obtain a high compression ratio, affects the visual quality of the reconstructed sequence. In this pa-per we present a joint optimization algorithm that controls the bit rate produced by a H.264 video encoder and a FEC-based cross-packet channel coder. The number of bits pro-duced by the video coder is associated to the percentage of null quantized DCT coefficients (“zeros”). The same pa-rameter is used to control a RTP-based FEC coding scheme detecting those parts of the bit stream that contain essential information for the decoding process and adaptively varying the amount of redundancy introduced in the bit stream. I