1. A decoding device comprising: circuitry configured to receive encoded data, the encoded data including: a first syntax called from a syntax that stores a parameter influencing a whole frame and that is a syntax on an upper level to a slice level, the first syntax being used for a weighted motion-compensated prediction and describing a plurality of parameters that are specified by a reference number and that include weighting factors, and a second syntax that stores a parameter influencing a whole sequence and that is a syntax on an upper level to the slice level, the second syntax describing a syntax element specifying a maximum number of values taken by the reference number, regenerate the syntax element from the second syntax, specify the plurality of parameters from the regenerated syntax element and the first syntax by using the reference number with the maximum number as an upper limit, and specify a reference image from a first reference image list and a second reference image list by using the reference number.