Encoding and decoding methods and apparatuses, coder-side devices and decoder-side devices are provided, the method includes: obtaining a weighted prediction angle and weight configuration parameters of the current block; where the weight configuration parameters include a weight transform rate and a weight transform start position; configuring reference weight values for surrounding positions outside the current block according to the weight configuration parameters; determining a surrounding matching position to which the pixel position points from the surrounding positions outside the current block based on the weighted prediction angle; determining a target weight value of the pixel position based on the reference weight value associated with the surrounding matching position, determining an association weight value of the pixel position based on the target weight value of the pixel position; determining a first prediction value of the pixel position based on a first prediction mode, determining a second prediction value of the pixel position based on a second prediction mode; determining a weighted prediction value of the pixel position based on the first prediction value, the target weight value, the second prediction value and the association weight value.