Intra-frame coding method and apparatus, frame coder, and frame coding system

An apparatus for determining an intra-frame prediction mode of a current video block, comprising:

• a processor;
• and
• a memory, configured to store computer-executable instructions, the instructions, when executed by the processor, causing the processor to:
• determine, in an image area including a to-be-coded current video block, a plurality of intra-frame prediction modes of a plurality of second video blocks with determined prediction modes as reference modes of the current video block, the image area being in an area defined by an adjacent CU and a father CU corresponding to the current video block in a video frame or slice including the current video block;
• and
• determine an alternative prediction mode set from preset intra-frame prediction modes, the alternative prediction mode set comprising a plurality of alternative prediction modes including the reference modes;
• and determine, in the alternative prediction mode set, a prediction mode having optimal intra-frame prediction coding performance on the current video block as an intra-frame prediction mode of the current video block.

A non-transitory computer-readable storage medium, storing computer-readable instructions, the instructions being executable by one or more processors to implement a method comprising:

• determining, in an image area including a to-be-coded current video block, reference modes of the current video block based on a plurality of intra-frame prediction modes of a plurality of second video blocks of with determined prediction modes, the image area being in an area defined by an adjacent coding unit (CU) and a Father CU corresponding to the current video block in a video frame or slice including the current video block;
• determining an alternative prediction mode set from preset intra-frame prediction modes, the alternative prediction mode set comprising a plurality of alternative prediction modes, including the reference modes;
• and
• determining, in the alternative prediction mode set, a prediction mode having optimal intra-frame prediction coding performance on the current video block as an intra-frame prediction mode of the current video block.