|
Chris@69
|
1 /***********************************************************************
|
|
Chris@69
|
2 Copyright (c) 2006-2011, Skype Limited. All rights reserved.
|
|
Chris@69
|
3 Redistribution and use in source and binary forms, with or without
|
|
Chris@69
|
4 modification, are permitted provided that the following conditions
|
|
Chris@69
|
5 are met:
|
|
Chris@69
|
6 - Redistributions of source code must retain the above copyright notice,
|
|
Chris@69
|
7 this list of conditions and the following disclaimer.
|
|
Chris@69
|
8 - Redistributions in binary form must reproduce the above copyright
|
|
Chris@69
|
9 notice, this list of conditions and the following disclaimer in the
|
|
Chris@69
|
10 documentation and/or other materials provided with the distribution.
|
|
Chris@69
|
11 - Neither the name of Internet Society, IETF or IETF Trust, nor the
|
|
Chris@69
|
12 names of specific contributors, may be used to endorse or promote
|
|
Chris@69
|
13 products derived from this software without specific prior written
|
|
Chris@69
|
14 permission.
|
|
Chris@69
|
15 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
Chris@69
|
16 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
Chris@69
|
17 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
Chris@69
|
18 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
Chris@69
|
19 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
Chris@69
|
20 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
Chris@69
|
21 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
Chris@69
|
22 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
Chris@69
|
23 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
Chris@69
|
24 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
Chris@69
|
25 POSSIBILITY OF SUCH DAMAGE.
|
|
Chris@69
|
26 ***********************************************************************/
|
|
Chris@69
|
27
|
|
Chris@69
|
28 #ifdef HAVE_CONFIG_H
|
|
Chris@69
|
29 #include "config.h"
|
|
Chris@69
|
30 #endif
|
|
Chris@69
|
31
|
|
Chris@69
|
32 #include "SigProc_FLP.h"
|
|
Chris@69
|
33
|
|
Chris@69
|
34 silk_float silk_schur_FLP( /* O returns residual energy */
|
|
Chris@69
|
35 silk_float refl_coef[], /* O reflection coefficients (length order) */
|
|
Chris@69
|
36 const silk_float auto_corr[], /* I autocorrelation sequence (length order+1) */
|
|
Chris@69
|
37 opus_int order /* I order */
|
|
Chris@69
|
38 )
|
|
Chris@69
|
39 {
|
|
Chris@69
|
40 opus_int k, n;
|
|
Chris@69
|
41 double C[ SILK_MAX_ORDER_LPC + 1 ][ 2 ];
|
|
Chris@69
|
42 double Ctmp1, Ctmp2, rc_tmp;
|
|
Chris@69
|
43
|
|
Chris@69
|
44 celt_assert( order >= 0 && order <= SILK_MAX_ORDER_LPC );
|
|
Chris@69
|
45
|
|
Chris@69
|
46 /* Copy correlations */
|
|
Chris@69
|
47 k = 0;
|
|
Chris@69
|
48 do {
|
|
Chris@69
|
49 C[ k ][ 0 ] = C[ k ][ 1 ] = auto_corr[ k ];
|
|
Chris@69
|
50 } while( ++k <= order );
|
|
Chris@69
|
51
|
|
Chris@69
|
52 for( k = 0; k < order; k++ ) {
|
|
Chris@69
|
53 /* Get reflection coefficient */
|
|
Chris@69
|
54 rc_tmp = -C[ k + 1 ][ 0 ] / silk_max_float( C[ 0 ][ 1 ], 1e-9f );
|
|
Chris@69
|
55
|
|
Chris@69
|
56 /* Save the output */
|
|
Chris@69
|
57 refl_coef[ k ] = (silk_float)rc_tmp;
|
|
Chris@69
|
58
|
|
Chris@69
|
59 /* Update correlations */
|
|
Chris@69
|
60 for( n = 0; n < order - k; n++ ) {
|
|
Chris@69
|
61 Ctmp1 = C[ n + k + 1 ][ 0 ];
|
|
Chris@69
|
62 Ctmp2 = C[ n ][ 1 ];
|
|
Chris@69
|
63 C[ n + k + 1 ][ 0 ] = Ctmp1 + Ctmp2 * rc_tmp;
|
|
Chris@69
|
64 C[ n ][ 1 ] = Ctmp2 + Ctmp1 * rc_tmp;
|
|
Chris@69
|
65 }
|
|
Chris@69
|
66 }
|
|
Chris@69
|
67
|
|
Chris@69
|
68 /* Return residual energy */
|
|
Chris@69
|
69 return (silk_float)C[ 0 ][ 1 ];
|
|
Chris@69
|
70 }
|
