12bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian/***********************************************************************
22bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianCopyright (c) 2006-2011, Skype Limited. All rights reserved.
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152bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianTHIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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182bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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212bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianSUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
222bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianINTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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252bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianPOSSIBILITY OF SUCH DAMAGE.
262bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian***********************************************************************/
272bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian
282bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian#ifdef HAVE_CONFIG_H
292bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian#include "config.h"
302bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian#endif
312bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian
322bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian#include "SigProc_FIX.h"
332bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian#include "resampler_private.h"
342bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian
352bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian/* Second order AR filter with single delay elements */
362bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanianvoid silk_resampler_private_AR2(
372bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    opus_int32                      S[],            /* I/O  State vector [ 2 ]          */
382bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    opus_int32                      out_Q8[],       /* O    Output signal               */
392bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    const opus_int16                in[],           /* I    Input signal                */
402bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    const opus_int16                A_Q14[],        /* I    AR coefficients, Q14        */
412bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    opus_int32                      len             /* I    Signal length               */
422bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian)
432bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian{
442bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    opus_int32    k;
452bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    opus_int32    out32;
462bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian
472bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    for( k = 0; k < len; k++ ) {
482bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        out32       = silk_ADD_LSHIFT32( S[ 0 ], (opus_int32)in[ k ], 8 );
492bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        out_Q8[ k ] = out32;
502bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        out32       = silk_LSHIFT( out32, 2 );
512bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        S[ 0 ]      = silk_SMLAWB( S[ 1 ], out32, A_Q14[ 0 ] );
522bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        S[ 1 ]      = silk_SMULWB( out32, A_Q14[ 1 ] );
532bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    }
542bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian}
552bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian
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