Robust Video Transmission Using Adaptive Bit Allocation

摘要

A jointly designed source-channel coding technique that protects video signals against transmission errors is proposed in this work. We develop a low-complexity source model which can estimate the bitrate and the quantization error for each packet. Also, the channel distortion is estimated based on the packet importance and the packet loss rate. The packet importance is measured as the mean square error between the error-free reconstruction and the concealed reconstruction, and the packet loss rate is determined by channel conditions. According to the informed channel condition, the encoder adaptively assigns the quantization parameter and the channel code rate to each packet so that the expected mean square error due to source and channel distortions is minimized subject to a constraint on the overall bitrate. Simulation results show that the proposed adaptive system provides acceptable image quality even in a high bit error rate environment.