|Bit allocation generator for adaptive transform coder
|AT&T Bell Laboratories
|May 7, 1985/ June 30, 1982
|Ching; Yau-Chau, Tomcik; James D.
|Adaptive bit allocation scheme for transform speech encoders. Seems to predate using perceptual distortion criteria.
|Adaptive bit allocation to a set of spectral transform coefficients is optimized by setting a predetermined first (maximum) threshold, then allocating one bit to those coefficients above the threshold, no bits to those below. If the total number of bits has not been allocated, the threshold is lowered an "integer" step to a second threshold, and again one bit allocated to those coefficients above the second threshold. The procedure is iterated until all the total bits are allocated or, if too many bits are allocated after the last integer step, a "fractional" step threshold is used.