A PERCEPTUALLY MOTIVATED TRELLIS BASED RATE CONTROL METHOD AND APPARATUS FOR LOW BIT RATE VIDEO CODING

摘要

A method and apparatus for compressing and transmitting variable amounts of video data in real time over a channel having a fixed bandwidth. A trellis having a plurality of nodes is provided. Each of the plurality of nodes has an associated quantization parameter and bit number. The bit number associated with each node corresponds to a quantity of bits consumed in reaching that node. For each of the plurality of blocks, a minimum path through the trellis is selected. A quantization parameter associated with the selected minimum path is selected. A number of bits is assigned to each of the plurality of blocks in accordance with the selected quantization parameter. A substantially fixed number of bits is distributed among the plurality of blocks which make up each of the plurality of frames in accordance with the selected quantization parameter. The number of bits per frame is substantially constant for each of the plurality of frames, and the distribution of bits within each of the plurality of frames varies in accordance with the content of the frame.