| 摘要 |
PURPOSE: An adaptive quantization coefficient generator is provided to effectively supply an adaptive quantization step and weight value to smooth the performance of quantization and improves stability and reliability of a system. CONSTITUTION: An adaptive quantization coefficient generator includes a DCT unit(300) for discrete-cosine-transforming a video input signal, a regular variance calculator(310) for extracting a variance from the input signal before the signal passes through DCT unit, and a quantization step calculator(320) for receiving the variance output from the regular variance calculator, a quantization mode and a quantization step code sent from an external buffer controller to calculate a linear quantization step and a nonlinear quantization step. The generator further has a quantization weight value processor(330) for continuously providing an adaptive quantization coefficient required for adaptive quantization, storing a quantization coefficient table received from a controller in a predetermined area, and performing quantization using a stored value. The generator also includes a multiplier(340) for multiplying quantization data output from the quantization step calculator by quantization data output from the quantization weight value processor, and a quantizer(350) for quantizing data output from the DCT unit, quantization step calculator, quantization weight value processor, and multiplier. |
