| 摘要 |
There is provided a code amount control device for controlling a code amount in units of second blocks each consisting of a plurality of first blocks each consisting of a plurality of sample value data, including a quantization unit for quantizing the second block data with predetermined quantization parameters, a detection unit for detecting the code amount of the second block data quantized by the quantization unit, and a control unit for controlling the quantization parameters in units of first blocks in accordance with an output from the detection unit. There is also provided an encoding apparatus including a block forming unit for dividing an input signal into blocks each consisting of a plurality of sample values, an orthogonal conversion unit for orthogonally converting the input signal blocks, a detection unit for detecting the characteristic of each block in accordance with orthogonal conversion coefficients obtained by the orthogonal conversion unit, a selection unit for selecting optimal quantization parameters which can realize a constant code amount obtained when the input signal blocks are encoded in a unit consisting of a plurality of input signal blocks, a changing unit for changing the quantization parameters selected by the selection unit in accordance with an output from the detection unit, and an encoding unit for encoding the orthogonal conversion coefficients from the orthogonal conversion unit using the quantization parameters changed by the changing unit. <IMAGE> |
