Abstract: A blocking effect attenuation apparatus for a high definition television receiver, includes a variable length decoder for receiving encoded video data and extracting therefrom a quantization level, a quantized DCT coefficient and a motion vector, an inverse quantizer for generating a DCT coefficient by convening the quantized DCT coefficient from the variable length decoder into frequency domain data according to the quantization level from the variable length decoder, an inverse DCT unit for restoring the DCT coefficient from the inverse quantizer into spatial domain data, a frame memory for storing video data of a previous frame, an adder for adding data output from the frame memory to data output from the inverse DCT unit to output video data of a present frame, a motion estimator for transferring the motion vector from the variable length decoder to the frame memory, a block analysis circuit for generating a filtering flag in response to the quantization level and the quantized DCT coefficient from the va