An embedded stereo speech and audio coding method based on principal component analysis

In this paper a compressive sampling method of MLT coefficients which is used for extracting stereo information is adopted based on principal component analysis (PCA) and Modulated Lapped Transform (MLT). With this method, an embedded variable bit-rates stereo speech and audio coding algorithm is proposed in this paper. In this codec, the stereo signal sampled at 32 kHz and 16 kHz can be coded in terms of scalable bit rates, the structure of bit-stream is embedded and the bit-stream can be divided into several layers. The core codec is ITU-T G.729.1 which can process mono signal with 7 kHz bandwidth. Besides there are four extra bit-rates added include 40, 48, 56, and 64kb/s. The maximum bit-rates of wideband stereo signal and super-wideband stereo signal are 48kb/s and 64kb/s, respectively. The objective and subjective test results show that the quality of the proposed codec is no worse than the reference codec which is requested by ITU-T.