.\" Copyright (c) 1987-1990 Entropic Speech, Inc..\" Copyright (c) 1991-1997 Entropic Research Laboratory, Inc. All rights reserved..\" @(#)lsftopc.3	1.6 18 Apr 1997 ESI/ERL.ds ]W (c) 1997 Entropic Research Laboratory, Inc..if n .ds - ---.if t .ds - \(em\h'-0.2m'\(em.TH LSF_TO_PC \3-ESPSsp 18 Apr 1997.SH NAMElsf_to_pc \- convert line spectral frequencies to linear prediction coefficients.SH SYNOPSIS.ft Bint lsf_to_pc(lsf, pc, order, bandwidth).brfloat   pc[], lsf[], bandwidth;.brint     order;.SH DESCRIPTIONThis routine takes an input vector.I lsfof line spectral frequencies (see [1]) and computes the correspondinglinear prediction coefficients.I pc,also known as autoregressive filter coefficientsor prediction-error filter coefficients.The convention adopted is that the first such coefficient is \-1,and it does not appear in the output vector.The argument.I orderis the analysis filter order\*-i.e. the number of input.I lsfparameters and the number of output .I pccoefficients\*-and.I bandwidthshould equal one-half the sampling frequency of the original sampled data..SH ASSUMPTIONSThis routine assumes that .I orderis even..SH BUGSNone known..SH REFERENCES[1] G. S. Kang and L. J. Fransen,.I Low-Bit Rate Speech Encoders Based on Line-Spectrum Frequencies (LSFs),NRL Report 8857, Naval Research Laboratory, Washington, D.C., January, 1985..SH AUTHORManual page D. Burton, Code by D. Burton