| 摘要 |
A variable rate vector quantization apparatus (22) and method employs a tree structured codebook. Code vectors are selected from different levels of the codebook according to the value of a threshold. The value of the treshold is periodically adjusted according to the fullness of a buffer that stores vector quantized data to be transmitted. According to the invention, vector quantized data for redundant, or similar vectors is not transmitted. Rather, a "copy last vector" instruction is transmitted for these vectors to achieve further data compression. A method of mean removal from vectors to be vector quantized is also disclosed. |
