Wavelet filter bank based wide-band audio coder
Jan Nováček · The Journal of the Acoustical Society of America · 2008
New system for wide-band audio signals compression is presented. The system is based on a two stage wavelet filter bank principle. Special psychoacoustic model was designed for the system. Data compression is nowadays very topical issue. Due to the development of information technologies more sophisticated compression algorithms may be designed. Most of the present compression systems, e.g. MPEG, ATRAC or Vorbis, use a simple filter bank or DCT transformation. Both methods suffer from the origin of undesirable artefacts which are disturbing for the sound perception. Wavelet filter bank is used to suppress these artefacts and to increase data compression. Frequency dependant windowing function is used for improve of frequency resolution at low frequencies along with faster response at high frequencies. Wavelet transformation based coding algorithm can improve temporal masking effects over conventional perceptual coding algorithms for data compression.