In the real-time video transmission such as video streaming, the additional channel coding is an effective method to overcome the packet loss problem. For such a joint source-channel coding system, the rate allocation to the source code and channel code is a critical problem in providing best video quality at the receiver. One need to calculate the optimal code rate defined in terms of video quality, packet loss probability, and channel bitrate.
In this paper, we propose an effective method to get the optimal code rate in the case of H.263 for the source coding, and the Reed-Solomon code for the channel coding. To obtain the optimal code rate approximately, we use to linear relationships. One is a linearity in logarithms scale between residual packet loss probability and the channel packet loss probability. The other is a linearity between the decrement in peak SNR and channel packet loss probability. It is shown by simulation that the proposed method can decide the optimal code rate almost precisely without full evaluation of relevant results.
