Band Expansion Technology Based on MDFT
Pan Xingd · Audio Engineering · 2015
A band extension technology based on discrete Fourier transform( MDFT) domain is proposed,which can effectively improve the audio coding efficiency. Relative to the existing method,the frequency band can be extended in MDFT domain and coordinated with the MDCT transform in low frequency coding. The existing data are effectively used during the low frequency encoding,and the efficiency of high frequency parameter coding is improved by a flexible way of block switching. MDFT is avoided since MDFT domain spectrum is converted directly through MDCT domain spectrum,thus the computational complexity of the decoder is effectively reduced with maintaining the quality of the audio signal coding.