Improved AAC performance @ < 64 kb/s using VQ

MPEG-4 Advanced Audio Coder performance can be improved, by reducing the bit load of "side information" and better utilization of the realized bits. Emphasizing the first part, using bitrate independent VQ codebooks for scale factors, it is shown that reconstruction quality can be improved at all bitrates, by a perceptually significant margin. The VQ complexity is also not much because of the sufficiency of smaller number of bits for the SCF vector.