| 摘要 |
PURPOSE:To prevent picture quality from being deteriorated by multiplexing information data with encoded video data during the vertical blanking period of a video signal. CONSTITUTION:An inputted digital signal is divided into blocks each of which consists of 8X8 picture elements to be an encoding processing unit, a luminance signal and a chrominance signal are converted into block data S100 in each processing unit and the block data S100 are sent to a mode judging circuit 110, an arithmetic circuit 120 and a forecasting encoding circuit 130. The circuit 120 calculates respective data power of data S102 obtained by subtracting the forecasting data S101 of the circuit 130 from the data S100 and the data S100 itself and supplies data 103 having smaller data power to a DCT circuit 150. Intra-frame encoding is executed based upon the data S100 and inter-frame encoding is executed based upon the encoding of difference value data 102. Since there is no video data in the vertical blanking period of an image, writing/ reading operation is not executed. Consequently control operation for the generation quantity 1 of encoded video data is not influenced by multiplexing operation and the deterioration of picture quality can be prevented. |
