A lossless coding technique for near-logarithmic companded PCM that achieves high compression performance is provided. In coding, the coding method that produces the smaller code amount is selected between the prediction coding method, which performs linear prediction of samples in a frame and codes the amplitude of the prediction error, and the normalization coding method, which normalizes the amplitude of the samples in the frame and codes the normalized amplitude, and a selection code that indicates the selection result is output. The samples in the frame are coded according to the selected coding method to produce a compression code. In decoding, the compression code is decoded according to a decoding process corresponding to the coding method specified by the selection code.