Improving the adaptive codebook delay selection for FS-1016 CELP

A limitation of the US federal standard 1016 CELP is the occurrence of adaptive delay estimation errors, particularly in the voiced/unvoiced transition areas. Delayed decision is applied in the analysis by synthesis loop of the analyzer to improve the selection of the adaptive delay, and the corresponding gain, by minimizing the weighted error criterion over the entire analysis frame instead of over the subframe. Full interoperability with the FS-1016 CELP standard is maintained.