media/libopus/silk/resampler_private_AR2.c

changeset 0
6474c204b198
     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/media/libopus/silk/resampler_private_AR2.c	Wed Dec 31 06:09:35 2014 +0100
     1.3 @@ -0,0 +1,55 @@
     1.4 +/***********************************************************************
     1.5 +Copyright (c) 2006-2011, Skype Limited. All rights reserved.
     1.6 +Redistribution and use in source and binary forms, with or without
     1.7 +modification, are permitted provided that the following conditions
     1.8 +are met:
     1.9 +- Redistributions of source code must retain the above copyright notice,
    1.10 +this list of conditions and the following disclaimer.
    1.11 +- Redistributions in binary form must reproduce the above copyright
    1.12 +notice, this list of conditions and the following disclaimer in the
    1.13 +documentation and/or other materials provided with the distribution.
    1.14 +- Neither the name of Internet Society, IETF or IETF Trust, nor the
    1.15 +names of specific contributors, may be used to endorse or promote
    1.16 +products derived from this software without specific prior written
    1.17 +permission.
    1.18 +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    1.19 +AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    1.20 +IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    1.21 +ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
    1.22 +LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
    1.23 +CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
    1.24 +SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    1.25 +INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
    1.26 +CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
    1.27 +ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    1.28 +POSSIBILITY OF SUCH DAMAGE.
    1.29 +***********************************************************************/
    1.30 +
    1.31 +#ifdef HAVE_CONFIG_H
    1.32 +#include "config.h"
    1.33 +#endif
    1.34 +
    1.35 +#include "SigProc_FIX.h"
    1.36 +#include "resampler_private.h"
    1.37 +
    1.38 +/* Second order AR filter with single delay elements */
    1.39 +void silk_resampler_private_AR2(
    1.40 +    opus_int32                      S[],            /* I/O  State vector [ 2 ]          */
    1.41 +    opus_int32                      out_Q8[],       /* O    Output signal               */
    1.42 +    const opus_int16                in[],           /* I    Input signal                */
    1.43 +    const opus_int16                A_Q14[],        /* I    AR coefficients, Q14        */
    1.44 +    opus_int32                      len             /* I    Signal length               */
    1.45 +)
    1.46 +{
    1.47 +    opus_int32    k;
    1.48 +    opus_int32    out32;
    1.49 +
    1.50 +    for( k = 0; k < len; k++ ) {
    1.51 +        out32       = silk_ADD_LSHIFT32( S[ 0 ], (opus_int32)in[ k ], 8 );
    1.52 +        out_Q8[ k ] = out32;
    1.53 +        out32       = silk_LSHIFT( out32, 2 );
    1.54 +        S[ 0 ]      = silk_SMLAWB( S[ 1 ], out32, A_Q14[ 0 ] );
    1.55 +        S[ 1 ]      = silk_SMULWB( out32, A_Q14[ 1 ] );
    1.56 +    }
    1.57 +}
    1.58 +

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