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#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "SigProc_FIX.h"

/* Chirp (bandwidth expand) LP AR filter.

   This logic is reused in _celt_lpc(). Any bug fixes should also be applied there. */

void silk_bwexpander_32(

    opus_int32                  *ar,                /* I/O  AR filter to be expanded (without leading 1)                */

    const opus_int              d,                  /* I    Length of ar                                                */

    opus_int32                  chirp_Q16           /* I    Chirp factor in Q16                                         */

)

{

    opus_int   i;

    opus_int32 chirp_minus_one_Q16 = chirp_Q16 - 65536;

    for( i = 0; i < d - 1; i++ ) {

        ar[ i ]    = silk_SMULWW( chirp_Q16, ar[ i ] );

        chirp_Q16 += silk_RSHIFT_ROUND( silk_MUL( chirp_Q16, chirp_minus_one_Q16 ), 16 );

    }

    ar[ d - 1 ] = silk_SMULWW( chirp_Q16, ar[ d - 1 ] );

}