diff options
Diffstat (limited to 'lib/rbcodec/codecs/libopus/silk/float/schur_FLP.c')
-rw-r--r-- | lib/rbcodec/codecs/libopus/silk/float/schur_FLP.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/libopus/silk/float/schur_FLP.c b/lib/rbcodec/codecs/libopus/silk/float/schur_FLP.c new file mode 100644 index 0000000000..8526c748d3 --- /dev/null +++ b/lib/rbcodec/codecs/libopus/silk/float/schur_FLP.c | |||
@@ -0,0 +1,70 @@ | |||
1 | /*********************************************************************** | ||
2 | Copyright (c) 2006-2011, Skype Limited. All rights reserved. | ||
3 | Redistribution and use in source and binary forms, with or without | ||
4 | modification, are permitted provided that the following conditions | ||
5 | are met: | ||
6 | - Redistributions of source code must retain the above copyright notice, | ||
7 | this list of conditions and the following disclaimer. | ||
8 | - Redistributions in binary form must reproduce the above copyright | ||
9 | notice, this list of conditions and the following disclaimer in the | ||
10 | documentation and/or other materials provided with the distribution. | ||
11 | - Neither the name of Internet Society, IETF or IETF Trust, nor the | ||
12 | names of specific contributors, may be used to endorse or promote | ||
13 | products derived from this software without specific prior written | ||
14 | permission. | ||
15 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | ||
16 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
17 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | ||
18 | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE | ||
19 | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | ||
20 | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | ||
21 | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | ||
22 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | ||
23 | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | ||
24 | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | ||
25 | POSSIBILITY OF SUCH DAMAGE. | ||
26 | ***********************************************************************/ | ||
27 | |||
28 | #ifdef HAVE_CONFIG_H | ||
29 | #include "config.h" | ||
30 | #endif | ||
31 | |||
32 | #include "SigProc_FLP.h" | ||
33 | |||
34 | silk_float silk_schur_FLP( /* O returns residual energy */ | ||
35 | silk_float refl_coef[], /* O reflection coefficients (length order) */ | ||
36 | const silk_float auto_corr[], /* I autocorrelation sequence (length order+1) */ | ||
37 | opus_int order /* I order */ | ||
38 | ) | ||
39 | { | ||
40 | opus_int k, n; | ||
41 | double C[ SILK_MAX_ORDER_LPC + 1 ][ 2 ]; | ||
42 | double Ctmp1, Ctmp2, rc_tmp; | ||
43 | |||
44 | celt_assert( order >= 0 && order <= SILK_MAX_ORDER_LPC ); | ||
45 | |||
46 | /* Copy correlations */ | ||
47 | k = 0; | ||
48 | do { | ||
49 | C[ k ][ 0 ] = C[ k ][ 1 ] = auto_corr[ k ]; | ||
50 | } while( ++k <= order ); | ||
51 | |||
52 | for( k = 0; k < order; k++ ) { | ||
53 | /* Get reflection coefficient */ | ||
54 | rc_tmp = -C[ k + 1 ][ 0 ] / silk_max_float( C[ 0 ][ 1 ], 1e-9f ); | ||
55 | |||
56 | /* Save the output */ | ||
57 | refl_coef[ k ] = (silk_float)rc_tmp; | ||
58 | |||
59 | /* Update correlations */ | ||
60 | for( n = 0; n < order - k; n++ ) { | ||
61 | Ctmp1 = C[ n + k + 1 ][ 0 ]; | ||
62 | Ctmp2 = C[ n ][ 1 ]; | ||
63 | C[ n + k + 1 ][ 0 ] = Ctmp1 + Ctmp2 * rc_tmp; | ||
64 | C[ n ][ 1 ] = Ctmp2 + Ctmp1 * rc_tmp; | ||
65 | } | ||
66 | } | ||
67 | |||
68 | /* Return residual energy */ | ||
69 | return (silk_float)C[ 0 ][ 1 ]; | ||
70 | } | ||