| 摘要 |
PURPOSE: A quantizer is provided to reduce quantization error and simplify a circuit configuration, by performing quantization/dequantization functions using one multiplier. CONSTITUTION: A comparison and detection part(20) converts a DCT or IDCT input value(10) into an absolute value and judges a data format of the input value. A ROM table(30) divides a QP value by an inverse number and stores result data. The second multiplexor receives and outputs an output value of the ROM table or the QP value. A multiplier(60) multiplies an output signal of the comparison and detection part(20) and data of the ROM table to quantize and dequantize data. The third multiplexor(70) clamps and encodes an output value of the multiplier when operated as a quantizer. The fourth multiplexor(80) clamps and encodes an output value of the multiplier when operated as a dequantizer. The fifth multiplexor(90) receives and outputs one of output signals of the third and fourth multiplexors. |
