mirror of
https://github.com/ioquake/ioq3.git
synced 2024-11-10 07:11:46 +00:00
70 lines
3 KiB
C
70 lines
3 KiB
C
/***********************************************************************
|
|
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,
|
|
this list of conditions and the following disclaimer.
|
|
- Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in the
|
|
documentation and/or other materials provided with the distribution.
|
|
- Neither the name of Internet Society, IETF or IETF Trust, nor the
|
|
names of specific contributors, may be used to endorse or promote
|
|
products derived from this software without specific prior written
|
|
permission.
|
|
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
|
|
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
POSSIBILITY OF SUCH DAMAGE.
|
|
***********************************************************************/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
#include "config.h"
|
|
#endif
|
|
|
|
#include "SigProc_FLP.h"
|
|
|
|
silk_float silk_schur_FLP( /* O returns residual energy */
|
|
silk_float refl_coef[], /* O reflection coefficients (length order) */
|
|
const silk_float auto_corr[], /* I autocorrelation sequence (length order+1) */
|
|
opus_int order /* I order */
|
|
)
|
|
{
|
|
opus_int k, n;
|
|
double C[ SILK_MAX_ORDER_LPC + 1 ][ 2 ];
|
|
double Ctmp1, Ctmp2, rc_tmp;
|
|
|
|
silk_assert( order >= 0 && order <= SILK_MAX_ORDER_LPC );
|
|
|
|
/* Copy correlations */
|
|
k = 0;
|
|
do {
|
|
C[ k ][ 0 ] = C[ k ][ 1 ] = auto_corr[ k ];
|
|
} while( ++k <= order );
|
|
|
|
for( k = 0; k < order; k++ ) {
|
|
/* Get reflection coefficient */
|
|
rc_tmp = -C[ k + 1 ][ 0 ] / silk_max_float( C[ 0 ][ 1 ], 1e-9f );
|
|
|
|
/* Save the output */
|
|
refl_coef[ k ] = (silk_float)rc_tmp;
|
|
|
|
/* Update correlations */
|
|
for( n = 0; n < order - k; n++ ) {
|
|
Ctmp1 = C[ n + k + 1 ][ 0 ];
|
|
Ctmp2 = C[ n ][ 1 ];
|
|
C[ n + k + 1 ][ 0 ] = Ctmp1 + Ctmp2 * rc_tmp;
|
|
C[ n ][ 1 ] = Ctmp2 + Ctmp1 * rc_tmp;
|
|
}
|
|
}
|
|
|
|
/* Return residual energy */
|
|
return (silk_float)C[ 0 ][ 1 ];
|
|
}
|