www.pudn.com > AVS_M_ver10.rar > int_lpc.c

/* 
*********************************************************************** 
* COPYRIGHT AND WARRANTY INFORMATION 
* 
* Copyright 2007  Audio Video Coding Standard, Part ¢ú 
* 
* This software module was developed by AVS Audio sub-group 
* 
* DISCLAIMER OF WARRANTY 
* 
* These software programs are available to the users without any 
* license fee or royalty on an "as is" basis. The AVS disclaims 
* any and all warranties, whether express, implied, or statutory, 
* including any implied warranties of merchantability or of fitness 
* for a particular purpose. In no event shall the contributors or  
* the AVS be liable for any incidental, punitive, or consequential 
* damages of any kind whatsoever arising from the use of this program. 
* 
* This disclaimer of warranty extends to the user of this program 
* and user's customers, employees, agents, transferees, successors, 
* and assigns. 
* 
* The AVS does not represent or warrant that the program furnished 
* hereunder are free of infringement of any third-party patents. 
* Commercial implementations of AVS, including shareware, may be 
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* the AVS patent policy is available from the AVS Web site at 
* http://www.avs.org.cn 
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* THIS IS NOT A GRANT OF PATENT RIGHTS - SEE THE AVS PATENT POLICY. 
************************************************************************ 
*/ 
 
/*---------------------------------------------------------------------* 
 * routine int_lpc()                                                   * 
 * ~~~~~~~~~~~~~~~~~                                                   * 
 * Find the interpolated LPC parameters in every subframes.            * 
 *---------------------------------------------------------------------*/ 
#include "../include/amr_plus.h" 
void int_lpc_np1( 
  float isf_old[],  /* input : LSFs from past frame              */ 
  float isf_new[],  /* input : LSFs from present frame           */ 
  float a[],        /* output: LP coefficients in both subframes */ 
  int   nb_subfr,   /* input: number of subframe                 */ 
  int   m           /* input : order of LP filter                */ 
) 
{ 
  float isf[M], inc, fnew, fold, *p_a; 
  int i, k; 
  inc = 1.0f / (float)nb_subfr; 
  p_a = a; 
  fnew = 0.0f; 
  for (k=0; k