Video encoding method and apparatus and video decoding method and apparatus

Abstract

A video encoding method includes extracting at least one reference macroblock from each of a plurality of reference frames to generate a plurality of reference macroblocks, computing a linear sum of the reference macroblocks using weighting factors to generate a predictive macroblock, generating a motion vector between the video macroblock and the reference macroblock corresponding to the predictive macroblock, generating a prediction error signal between the predictive macroblock and the video macroblock, and encoding the prediction error signal, a first index indicating the plurality of reference frames, a second index indicating the weighting factors and the motion vector.

1 . A video decoding method of performing a motion compensated prediction interframe decoding on a to-be-decoded video block of a video picture, using a plurality of reference pictures and a motion vector between the to-be-decoded video block and at least one reference picture, the method comprising: 
 decoding encoded data including information items indicating a prediction error signal between a prediction block and the to-be-decoded video block, the reference picture, weighting factors, a DC offset value and the motion vector, respectively;    calculating a linear sum of the plurality of reference blocks extracted from the reference picture, using the weighting factor;    adding the DC offset value to the linear sum to generate the prediction block; and    generating a reproduction video signal by means of the prediction error signal and the prediction block,    wherein the weighting factor is expressed by a rational number using a denominator to be a power of 2 set for each encoded video picture, and decoding the encoded data includes decoding the denominator and a numerator of the rational number as the weighting factor.    
   
   
       2 . A video decoding apparatus configured to perform a motion compensated prediction interframe decoding on a to-be-decoded video block of a video picture, using a plurality of reference pictures and a motion vector between the to-be-decoded video block and at least one reference picture, the apparatus comprising: 
 a decoder configured to decode to-be-decoded data including information items indicating a prediction error signal between a prediction block and the to-be-decoded video block, the reference picture, weighting factors, a DC offset value and the motion vector, respectively;    a calculator configured to calculate a linear sum of the plurality of reference blocks extracted from the reference picture, using the weighting factor;    an adder configured to add the DC offset value to the linear sum to generate the prediction block; and    a signal generator configured to generate a reproduction video signal by means of the prediction error signal and the prediction block,    wherein the weighting factor is expressed by a rational number using a denominator to be a power of 2 set for each encoded video picture, and the decoder includes a decoder to decode the denominator and a numerator of the rational number as the weighting factor.