Predictive LSF computation

This paper presents a new method for computing the line spectral frequencies (LSF). The new features of the method consist in: (1) the use of predictions of the LSFs as starting points for the search of the current LSFs, (2) the fast bracketing of the LSFs working on a grid of points and (3) the refinement of LSFs by a variable number of bisections. The method provides an easy control of the trade off between necessary accuracy and worst case computational time and is easily tunable to different orders of prediction polynomials. The experimental results show an improvement of the average performance with more than 30% with respect to a frequently used method (Kabal-Ramachandran).