1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/media/libopus/silk/float/schur_FLP.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,70 @@
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_FLP.h"
1.36 +
1.37 +silk_float silk_schur_FLP( /* O returns residual energy */
1.38 + silk_float refl_coef[], /* O reflection coefficients (length order) */
1.39 + const silk_float auto_corr[], /* I autocorrelation sequence (length order+1) */
1.40 + opus_int order /* I order */
1.41 +)
1.42 +{
1.43 + opus_int k, n;
1.44 + silk_float C[ SILK_MAX_ORDER_LPC + 1 ][ 2 ];
1.45 + silk_float Ctmp1, Ctmp2, rc_tmp;
1.46 +
1.47 + silk_assert( order==6||order==8||order==10||order==12||order==14||order==16 );
1.48 +
1.49 + /* Copy correlations */
1.50 + for( k = 0; k < order+1; k++ ) {
1.51 + C[ k ][ 0 ] = C[ k ][ 1 ] = auto_corr[ k ];
1.52 + }
1.53 +
1.54 + for( k = 0; k < order; k++ ) {
1.55 + /* Get reflection coefficient */
1.56 + rc_tmp = -C[ k + 1 ][ 0 ] / silk_max_float( C[ 0 ][ 1 ], 1e-9f );
1.57 +
1.58 + /* Save the output */
1.59 + refl_coef[ k ] = rc_tmp;
1.60 +
1.61 + /* Update correlations */
1.62 + for( n = 0; n < order - k; n++ ) {
1.63 + Ctmp1 = C[ n + k + 1 ][ 0 ];
1.64 + Ctmp2 = C[ n ][ 1 ];
1.65 + C[ n + k + 1 ][ 0 ] = Ctmp1 + Ctmp2 * rc_tmp;
1.66 + C[ n ][ 1 ] = Ctmp2 + Ctmp1 * rc_tmp;
1.67 + }
1.68 + }
1.69 +
1.70 + /* Return residual energy */
1.71 + return C[ 0 ][ 1 ];
1.72 +}
1.73 +
