Modeling of transmission-loss-induced distortion in decoded video

This paper analyzes the distortion in decoded video caused by random packet losses in the underlying transmission network. A recursion model is derived that relates the average channel-induced distortion in successive P-frames. The model is applicable to all video encoders using the block-based motion-compensated prediction framework (including the H.261/263/264 and MPEG1/2/4 video coding standards) and allows for any motion-compensated temporal concealment method at the decoder. The model explicitly considers the interpolation operation invoked for motion-compensated temporal prediction and concealment with sub-pel motion vectors. The model also takes into account the two new features of the H.264/AVC standard, namely intraprediction and in-loop deblocking filtering. A comparison with simulation data shows that the model is very accurate over a large range of packet loss rates and encoder intrablock rates. The model is further adapted to characterize the channel distortion in subsequent received frames after a single lost frame. This allows one to easily evaluate the impact of a single frame loss.