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     27 
     28 #ifdef HAVE_CONFIG_H
     29 #include "config.h"
     30 #endif
     31 
     32 #include "SigProc_FIX.h"
     33 /* Approximation of 128 * log2() (very close inverse of silk_log2lin()) */
     34 /* Convert input to a log scale    */
     35 opus_int32 silk_lin2log(
     36     const opus_int32            inLin               /* I  input in linear scale                                         */
     37 )
     38 {
     39     opus_int32 lz, frac_Q7;
     40 
     41     silk_CLZ_FRAC( inLin, &lz, &frac_Q7 );
     42 
     43     /* Piece-wise parabolic approximation */
     44     return silk_LSHIFT( 31 - lz, 7 ) + silk_SMLAWB( frac_Q7, silk_MUL( frac_Q7, 128 - frac_Q7 ), 179 );
     45 }
     46 
     47