HIGH EFFICIENCY ENCODER

摘要

PURPOSE:To provide improved high-speed reproducing pictures by dividing a discrete cosine transformation(DCT) block into low band side data and high band side data by a prescribed ratio and outputting encoded data in a prescribed order. CONSTITUTION:Digital video data inputted to a shuffling circuit 2 are blocked into the DCT blocks of 8 lines X8 picture elements and then, a shuffling processing is performed with the DCT block as a unit. in a DCT transforming unit 3, two-dimensional DCT transformation is executed to the DCT block and the digital data are quantized in a quantizer 4 based on a rate control variable outputted from a rate control circuit 7. The quantized data are variable length encoded in a variable length encoder 5 and outputted to a buffer 6. In the control circuit 7, the amount of the data stored in the buffer 6 is successively measured and a rate control coefficient is outputted to the quantizer 4. An output order switching circuit 9 separates the entire DCT blocks constituting one screen among the encoded data from the buffer 6 into the part of 50% from a low band side and the part of 50% on a high band side.