IHOLL
/
squeezelite-esp32
mirror of https://github.com/sle118/squeezelite-esp32


			
				
					
						
						
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							/***********************************************************************
Copyright (c) 2006-2011, Skype Limited. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
- Redistributions of source code must retain the above copyright notice,
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documentation and/or other materials provided with the distribution.
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names of specific contributors, may be used to endorse or promote
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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***********************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "SigProc_FIX.h"
#include "resampler_private.h"

/* Second order AR filter with single delay elements */
void silk_resampler_private_AR2(
    opus_int32                      S[],            /* I/O  State vector [ 2 ]          */
    opus_int32                      out_Q8[],       /* O    Output signal               */
    const opus_int16                in[],           /* I    Input signal                */
    const opus_int16                A_Q14[],        /* I    AR coefficients, Q14        */
    opus_int32                      len             /* I    Signal length               */
)
{
    opus_int32    k;
    opus_int32    out32;

    for( k = 0; k < len; k++ ) {
        out32       = silk_ADD_LSHIFT32( S[ 0 ], (opus_int32)in[ k ], 8 );
        out_Q8[ k ] = out32;
        out32       = silk_LSHIFT( out32, 2 );
        S[ 0 ]      = silk_SMLAWB( S[ 1 ], out32, A_Q14[ 0 ] );
        S[ 1 ]      = silk_SMULWB( out32, A_Q14[ 1 ] );
    }
}