A non-transitory computer-readable medium is provided. The non-transitory computer-readable medium having computer instructions stored therein, which when executed by one or more processors, cause the one or more processors to perform operations. The operations comprise: determining a channel combination scheme for a current frame, where the determined channel combination scheme for the current frame is one of a plurality of channel combination schemes; and determining a coding mode of the current frame based on a channel combination scheme for a previous frame and the channel combination scheme for the current frame, where the coding mode of the current frame is one of a plurality of coding modes.