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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 "main_FLP.h"
33 
34 #define MAX_ITERATIONS_RESIDUAL_NRG         10
35 #define REGULARIZATION_FACTOR               1e-8f
36 
37 /* Residual energy: nrg = wxx - 2 * wXx * c + c' * wXX * c */
silk_residual_energy_covar_FLP(const silk_float * c,silk_float * wXX,const silk_float * wXx,const silk_float wxx,const opus_int D)38 silk_float silk_residual_energy_covar_FLP(                              /* O    Weighted residual energy                    */
39     const silk_float                *c,                                 /* I    Filter coefficients                         */
40     silk_float                      *wXX,                               /* I/O  Weighted correlation matrix, reg. out       */
41     const silk_float                *wXx,                               /* I    Weighted correlation vector                 */
42     const silk_float                wxx,                                /* I    Weighted correlation value                  */
43     const opus_int                  D                                   /* I    Dimension                                   */
44 )
45 {
46     opus_int   i, j, k;
47     silk_float tmp, nrg = 0.0f, regularization;
48 
49     /* Safety checks */
50     celt_assert( D >= 0 );
51 
52     regularization = REGULARIZATION_FACTOR * ( wXX[ 0 ] + wXX[ D * D - 1 ] );
53     for( k = 0; k < MAX_ITERATIONS_RESIDUAL_NRG; k++ ) {
54         nrg = wxx;
55 
56         tmp = 0.0f;
57         for( i = 0; i < D; i++ ) {
58             tmp += wXx[ i ] * c[ i ];
59         }
60         nrg -= 2.0f * tmp;
61 
62         /* compute c' * wXX * c, assuming wXX is symmetric */
63         for( i = 0; i < D; i++ ) {
64             tmp = 0.0f;
65             for( j = i + 1; j < D; j++ ) {
66                 tmp += matrix_c_ptr( wXX, i, j, D ) * c[ j ];
67             }
68             nrg += c[ i ] * ( 2.0f * tmp + matrix_c_ptr( wXX, i, i, D ) * c[ i ] );
69         }
70         if( nrg > 0 ) {
71             break;
72         } else {
73             /* Add white noise */
74             for( i = 0; i < D; i++ ) {
75                 matrix_c_ptr( wXX, i, i, D ) +=  regularization;
76             }
77             /* Increase noise for next run */
78             regularization *= 2.0f;
79         }
80     }
81     if( k == MAX_ITERATIONS_RESIDUAL_NRG ) {
82         silk_assert( nrg == 0 );
83         nrg = 1.0f;
84     }
85 
86     return nrg;
87 }
88 
89 /* Calculates residual energies of input subframes where all subframes have LPC_order   */
90 /* of preceding samples                                                                 */
silk_residual_energy_FLP(silk_float nrgs[MAX_NB_SUBFR],const silk_float x[],silk_float a[2][MAX_LPC_ORDER],const silk_float gains[],const opus_int subfr_length,const opus_int nb_subfr,const opus_int LPC_order)91 void silk_residual_energy_FLP(
92     silk_float                      nrgs[ MAX_NB_SUBFR ],               /* O    Residual energy per subframe                */
93     const silk_float                x[],                                /* I    Input signal                                */
94     silk_float                      a[ 2 ][ MAX_LPC_ORDER ],            /* I    AR coefs for each frame half                */
95     const silk_float                gains[],                            /* I    Quantization gains                          */
96     const opus_int                  subfr_length,                       /* I    Subframe length                             */
97     const opus_int                  nb_subfr,                           /* I    number of subframes                         */
98     const opus_int                  LPC_order                           /* I    LPC order                                   */
99 )
100 {
101     opus_int     shift;
102     silk_float   *LPC_res_ptr, LPC_res[ ( MAX_FRAME_LENGTH + MAX_NB_SUBFR * MAX_LPC_ORDER ) / 2 ];
103 
104     LPC_res_ptr = LPC_res + LPC_order;
105     shift = LPC_order + subfr_length;
106 
107     /* Filter input to create the LPC residual for each frame half, and measure subframe energies */
108     silk_LPC_analysis_filter_FLP( LPC_res, a[ 0 ], x + 0 * shift, 2 * shift, LPC_order );
109     nrgs[ 0 ] = ( silk_float )( gains[ 0 ] * gains[ 0 ] * silk_energy_FLP( LPC_res_ptr + 0 * shift, subfr_length ) );
110     nrgs[ 1 ] = ( silk_float )( gains[ 1 ] * gains[ 1 ] * silk_energy_FLP( LPC_res_ptr + 1 * shift, subfr_length ) );
111 
112     if( nb_subfr == MAX_NB_SUBFR ) {
113         silk_LPC_analysis_filter_FLP( LPC_res, a[ 1 ], x + 2 * shift, 2 * shift, LPC_order );
114         nrgs[ 2 ] = ( silk_float )( gains[ 2 ] * gains[ 2 ] * silk_energy_FLP( LPC_res_ptr + 0 * shift, subfr_length ) );
115         nrgs[ 3 ] = ( silk_float )( gains[ 3 ] * gains[ 3 ] * silk_energy_FLP( LPC_res_ptr + 1 * shift, subfr_length ) );
116     }
117 }
118