Convention Paper
High Quality Sound Coding at 2.5 Bit/Sample
AES Convention 84 · Paper 2582 · March 1988
Abstract
The algorithm described in the paper allows a reduction of the bit rate needed for coding CD-quality signals to 2.5 bit/sample and still gain in subjective quality when compared with other known algorithms for high quality sound coding. Coding signals with a very sharp rise in amplitude (e.g. triangle or glockenspiel) induces short (e.g. 10ms) preechoes which are audible in some cases. This problem of all frequency domain coding algorithms can be reduced using a special "post filtering" algorithm together with a few bits of additional side information. Transform-based coding algorithms need overlapping and windowing of the input data blocks. With a new technique called time domain aliasing cancellation (TDAC) full overlapping of input blocks is possible without increasing the data rate needed for transmission.
