Title :
Enhanced wavelet based audio coder
Author :
Tewfik, Ahmed H. ; Ali, Murtaza
Author_Institution :
Dept. of Electr. Eng., Minnesota Univ., Minneapolis, MN, USA
Abstract :
Several enhancements on the wavelet based audio coder proposed by Sinha and Tewfik (see. Proceedings of the Int. Conf. of Acoust., Speech and Signal Proc. Society (ICASSP), vol.1, p.197-200, 1993) are discussed. These enhancements include use of temporal information in masking for audio segments with sudden change of amplitudes in them, efficient quantization of the variances and run-length coding for the zeros. Experiments suggest that these enhancements give almost transparent compression of monophonic CD quality audio signals (sampled at 44.1 kHz) at bit rates of 55-63 kbits/sec. We also discuss a real time implementation of a simplified version of the wavelet based audio coder at somewhat higher bit rates (64-78 kbits/sec)
Keywords :
analogue-digital conversion; audio equipment; audio signals; audio systems; data compression; encoding; wavelet transforms; 44.1 kHz; 55 to 63 kbit/s; 64 to 78 kbit/s; amplitudes; audio segments masking; monophonic CD quality audio signals; quantization; real time implementation; run-length coding; temporal information; transparent compression; variances; wavelet based audio coder; Bandwidth; Bit rate; CD recording; Discrete wavelet transforms; Frequency; Masking threshold; Phase change materials; Quantization; Sampling methods; Speech; Wavelet transforms;
Conference_Titel :
Signals, Systems and Computers, 1993. 1993 Conference Record of The Twenty-Seventh Asilomar Conference on
Conference_Location :
Pacific Grove, CA
Print_ISBN :
0-8186-4120-7
DOI :
10.1109/ACSSC.1993.342440
