| 摘要 |
PURPOSE:To suppress data quantity of picture data caused by quantization by making a quantization step size used for quantizing the picture data rough when it is judged that the form of the picture data is used for in-frame coding. CONSTITUTION:A quantization control unit 36 judges whether or not a macro block type is of in-frame coding block and whether or not a block not in accordance with a forced fresh block exists. When the macro block type is of in- frame coding type, if a quantization circuit 37 makes quantization in a fine quantization step size, overflow takes place to a buffer memory 32. Thus, the quantization control unit 36 sets the quantization step size QNT to an upper limit QNT to suppress the data quantity of a quantization data S39. As a result, overflow of the transmission buffer memory 32 is prevented in advance. |
