Scalable Audio Coding Based on Integer Transform

The modified discrete cosine transform (MDCT) is widely used in current perceptual audio coding schemes. This paper presents an integer approximation of this lapped transform, called integer MDCT, which is derived from the MDCT using lifting scheme. This reversible integer transform inherits most of the attractive properties of the MDCT, exhibiting a good spectral representation of the audio signal, critical sampling and overlapping, which makes the integer MDCT well suited for both lossless audio coding as well as for combined perceptual and lossless audio coding. A scalable system based on MPEG AAC and integer MDCT is presented providing a lossless enhancement of perceptual audio coding scheme.