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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 silk_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