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 #include "tuning_parameters.h" 34 35 void silk_find_LTP_FLP( 36 silk_float b[ MAX_NB_SUBFR * LTP_ORDER ], /* O LTP coefs */ 37 silk_float WLTP[ MAX_NB_SUBFR * LTP_ORDER * LTP_ORDER ], /* O Weight for LTP quantization */ 38 silk_float *LTPredCodGain, /* O LTP coding gain */ 39 const silk_float r_lpc[], /* I LPC residual */ 40 const opus_int lag[ MAX_NB_SUBFR ], /* I LTP lags */ 41 const silk_float Wght[ MAX_NB_SUBFR ], /* I Weights */ 42 const opus_int subfr_length, /* I Subframe length */ 43 const opus_int nb_subfr, /* I number of subframes */ 44 const opus_int mem_offset /* I Number of samples in LTP memory */ 45 ) 46 { 47 opus_int i, k; 48 silk_float *b_ptr, temp, *WLTP_ptr; 49 silk_float LPC_res_nrg, LPC_LTP_res_nrg; 50 silk_float d[ MAX_NB_SUBFR ], m, g, delta_b[ LTP_ORDER ]; 51 silk_float w[ MAX_NB_SUBFR ], nrg[ MAX_NB_SUBFR ], regu; 52 silk_float Rr[ LTP_ORDER ], rr[ MAX_NB_SUBFR ]; 53 const silk_float *r_ptr, *lag_ptr; 54 55 b_ptr = b; 56 WLTP_ptr = WLTP; 57 r_ptr = &r_lpc[ mem_offset ]; 58 for( k = 0; k < nb_subfr; k++ ) { 59 lag_ptr = r_ptr - ( lag[ k ] + LTP_ORDER / 2 ); 60 61 silk_corrMatrix_FLP( lag_ptr, subfr_length, LTP_ORDER, WLTP_ptr ); 62 silk_corrVector_FLP( lag_ptr, r_ptr, subfr_length, LTP_ORDER, Rr ); 63 64 rr[ k ] = ( silk_float )silk_energy_FLP( r_ptr, subfr_length ); 65 regu = 1.0f + rr[ k ] + 66 matrix_ptr( WLTP_ptr, 0, 0, LTP_ORDER ) + 67 matrix_ptr( WLTP_ptr, LTP_ORDER-1, LTP_ORDER-1, LTP_ORDER ); 68 regu *= LTP_DAMPING / 3; 69 silk_regularize_correlations_FLP( WLTP_ptr, &rr[ k ], regu, LTP_ORDER ); 70 silk_solve_LDL_FLP( WLTP_ptr, LTP_ORDER, Rr, b_ptr ); 71 72 /* Calculate residual energy */ 73 nrg[ k ] = silk_residual_energy_covar_FLP( b_ptr, WLTP_ptr, Rr, rr[ k ], LTP_ORDER ); 74 75 temp = Wght[ k ] / ( nrg[ k ] * Wght[ k ] + 0.01f * subfr_length ); 76 silk_scale_vector_FLP( WLTP_ptr, temp, LTP_ORDER * LTP_ORDER ); 77 w[ k ] = matrix_ptr( WLTP_ptr, LTP_ORDER / 2, LTP_ORDER / 2, LTP_ORDER ); 78 79 r_ptr += subfr_length; 80 b_ptr += LTP_ORDER; 81 WLTP_ptr += LTP_ORDER * LTP_ORDER; 82 } 83 84 /* Compute LTP coding gain */ 85 if( LTPredCodGain != NULL ) { 86 LPC_LTP_res_nrg = 1e-6f; 87 LPC_res_nrg = 0.0f; 88 for( k = 0; k < nb_subfr; k++ ) { 89 LPC_res_nrg += rr[ k ] * Wght[ k ]; 90 LPC_LTP_res_nrg += nrg[ k ] * Wght[ k ]; 91 } 92 93 silk_assert( LPC_LTP_res_nrg > 0 ); 94 *LTPredCodGain = 3.0f * silk_log2( LPC_res_nrg / LPC_LTP_res_nrg ); 95 } 96 97 /* Smoothing */ 98 /* d = sum( B, 1 ); */ 99 b_ptr = b; 100 for( k = 0; k < nb_subfr; k++ ) { 101 d[ k ] = 0; 102 for( i = 0; i < LTP_ORDER; i++ ) { 103 d[ k ] += b_ptr[ i ]; 104 } 105 b_ptr += LTP_ORDER; 106 } 107 /* m = ( w * d' ) / ( sum( w ) + 1e-3 ); */ 108 temp = 1e-3f; 109 for( k = 0; k < nb_subfr; k++ ) { 110 temp += w[ k ]; 111 } 112 m = 0; 113 for( k = 0; k < nb_subfr; k++ ) { 114 m += d[ k ] * w[ k ]; 115 } 116 m = m / temp; 117 118 b_ptr = b; 119 for( k = 0; k < nb_subfr; k++ ) { 120 g = LTP_SMOOTHING / ( LTP_SMOOTHING + w[ k ] ) * ( m - d[ k ] ); 121 temp = 0; 122 for( i = 0; i < LTP_ORDER; i++ ) { 123 delta_b[ i ] = silk_max_float( b_ptr[ i ], 0.1f ); 124 temp += delta_b[ i ]; 125 } 126 temp = g / temp; 127 for( i = 0; i < LTP_ORDER; i++ ) { 128 b_ptr[ i ] = b_ptr[ i ] + delta_b[ i ] * temp; 129 } 130 b_ptr += LTP_ORDER; 131 } 132 } 133
