The invention provides an IntMDCT-based lossless audio encoding method and decoding method. The encoding method includes the following steps that: (1) audio
time domain signals x (k) are framed, and a
single frame of
time domain signals x (k) can be obtained, wherein the k=0,..., N-1, wherein the N is frame length; (2) IntMDCT transformation is performed on the
time domain signals, so that
frequency domain signals X (m) can be obtained, wherein the m=0,..., N-1; and (3) Rice encoding is performed on the
frequency domain signals, so that code streams can be obtained. The decoding method is an inverse process of the encoding method and includes the following steps that: firstly, Rice decoding is performed on an inputted code
stream file, so that the
frequency domain signals X (m) can be obtained, wherein the m=0,..., N-1; and secondly, IntMDCT inverse transformation is performed, so that the time domain signals x (k) can be restored, wherein the k=0,..., N-1. With the methods of the invention adopted, encoding parameters can be obtained adaptively, and the value of
compression ratio is lower than that of block adaptive Rice, and the methods of the invention have a wider applicable range.