A multiresolution two-layer video codec for networking applications

We propose an improved multiresolution two-layer video codec that can operate at a base layer of 64 kbps and a variable bit rate second layer (VBR). The basic idea is to use a multiresolution technique to reduce the original CIF format video to the QCIF format. The low-resolution video is then encoded with an improved H.261 codec. To reduce the bit rate of the second layer, the residuals are encoded with the discrete cosine transform (DCT) using perceptually weighted quantization step sizes. Simulation results show that the Miss America sequence can be transmitted at 64 kbps in the CIF format with a reasonably good picture quality. For a good picture quality, the second layer would typically require 190 kbps.