Encoding method, decoding method, encoder, and decoder

Abstract

Disclosed is an intraframe prediction method, wherein for an intraframe predicted block in an interframe predicted frame, when an interframe predicted blocks exists on the lower right of the intraframe predicted block, a coding and decoding sequence of intraframe and interframe blocks is adjusted, and intraframe prediction is performed in a lower right intraframe prediction approach, i.e., performing prediction using the lower right reconstructed pixel value as the reference pixel point for the intraframe predicted block; at the coding procedure, each coded unit is first coded, and upon completion of the coding, information of all interframe predicted blocks is written into a code stream; next, two-pass coding is performed to the intraframe predicted block; lower right intraframe coding is performed during the two-pass coding process; after completion of the two-pass coding, the information of the intraframe predicted block is written into the code stream; at the decoding procedure, decoding of all interframe predicted blocks is first completed; then, lower right intraframe decoding is performed to the intraframe predicted blocks. The present disclosure may improve the intraframe prediction accuracy and enhance the coding efficiency of the intraframe predicted block in the interframe predicted frame.