Adaptive joint source-channel coding using rate shaping

We present in this paper an adaptive joint source-channel coding scheme using rate shaping on pre-coded video data. Rate shaping selectively drops portions of the video bitstream before transmitting them in order to satisfy the network bandwidth requirement. In wireless multimedia transport over heterogeneous networks, limited bandwidth is not the only issue. The high error rate of the channel should be considered as well, so channel coding is often applied. We propose a rate shaping method that drops not only the source-coding segments of the video bitstream, but also the channel-coding segments of the video bitstream, adaptively according to the network condition, in order to achieve the optimal rate-distortion performance. The proposed method is based on “discrete rate-distortion combination” to accomplish joint source-channel coding. We consider both the simulcast and multicast scenarios and show promising results.