Line data    Source code

       1             : /***********************************************************************
       2             : Copyright (c) 2006-2011, Skype Limited. All rights reserved.
       3             : Redistribution and use in source and binary forms, with or without
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      15             : THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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      22             : INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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      25             : POSSIBILITY OF SUCH DAMAGE.
      26             : ***********************************************************************/
      27             : 
      28             : #ifdef HAVE_CONFIG_H
      29             : #include "config.h"
      30             : #endif
      31             : 
      32             : #include "SigProc_FLP.h"
      33             : 
      34             : /* step up function, converts reflection coefficients to prediction coefficients */
      35           0 : void silk_k2a_FLP(
      36             :     silk_float          *A,                 /* O     prediction coefficients [order]                            */
      37             :     const silk_float    *rc,                /* I     reflection coefficients [order]                            */
      38             :     opus_int32          order               /* I     prediction order                                           */
      39             : )
      40             : {
      41             :     opus_int   k, n;
      42             :     silk_float rck, tmp1, tmp2;
      43             : 
      44           0 :     for( k = 0; k < order; k++ ) {
      45           0 :         rck = rc[ k ];
      46           0 :         for( n = 0; n < (k + 1) >> 1; n++ ) {
      47           0 :             tmp1 = A[ n ];
      48           0 :             tmp2 = A[ k - n - 1 ];
      49           0 :             A[ n ]         = tmp1 + tmp2 * rck;
      50           0 :             A[ k - n - 1 ] = tmp2 + tmp1 * rck;
      51             :         }
      52           0 :         A[ k ] = -rck;
      53             :     }
      54           0 : }