A variable bit rate layered DCT video coder for packet switched (ATM) networks

A combined inter/intra-frame discrete cosine transform (DCT) with layered transmission of (significant) coefficient sets is proposed. In the scheme, a whole frame is either intraframe or interframe coded based on the amount of motion. In the interframe mode, a vertical strip, which cycles periodically to refresh a section of the frame, is intraframe coded. This refresh feature preserves the synchronization in the event of cell loss. The layered transmission of the coefficients allows delivery of the desired quality video, after low-energy (layered) coefficients are selectively discarded, and immunity to cell loss is achieved by utilizing the correctly received layers to compensate for the effects of lost cells in reconstructing the frame blocks