| /*********************************************************************** |
| Copyright (c) 2006-2011, Skype Limited. All rights reserved. |
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| modification, are permitted provided that the following conditions |
| are met: |
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| this list of conditions and the following disclaimer. |
| - Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| - Neither the name of Internet Society, IETF or IETF Trust, nor the |
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| products derived from this software without specific prior written |
| permission. |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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| ***********************************************************************/ |
| |
| #ifdef HAVE_CONFIG_H |
| #include "config.h" |
| #endif |
| |
| #include "main_FLP.h" |
| #include "tuning_parameters.h" |
| |
| void silk_find_LTP_FLP( |
| silk_float b[ MAX_NB_SUBFR * LTP_ORDER ], /* O LTP coefs */ |
| silk_float WLTP[ MAX_NB_SUBFR * LTP_ORDER * LTP_ORDER ], /* O Weight for LTP quantization */ |
| silk_float *LTPredCodGain, /* O LTP coding gain */ |
| const silk_float r_lpc[], /* I LPC residual */ |
| const opus_int lag[ MAX_NB_SUBFR ], /* I LTP lags */ |
| const silk_float Wght[ MAX_NB_SUBFR ], /* I Weights */ |
| const opus_int subfr_length, /* I Subframe length */ |
| const opus_int nb_subfr, /* I number of subframes */ |
| const opus_int mem_offset /* I Number of samples in LTP memory */ |
| ) |
| { |
| opus_int i, k; |
| silk_float *b_ptr, temp, *WLTP_ptr; |
| silk_float LPC_res_nrg, LPC_LTP_res_nrg; |
| silk_float d[ MAX_NB_SUBFR ], m, g, delta_b[ LTP_ORDER ]; |
| silk_float w[ MAX_NB_SUBFR ], nrg[ MAX_NB_SUBFR ], regu; |
| silk_float Rr[ LTP_ORDER ], rr[ MAX_NB_SUBFR ]; |
| const silk_float *r_ptr, *lag_ptr; |
| |
| b_ptr = b; |
| WLTP_ptr = WLTP; |
| r_ptr = &r_lpc[ mem_offset ]; |
| for( k = 0; k < nb_subfr; k++ ) { |
| lag_ptr = r_ptr - ( lag[ k ] + LTP_ORDER / 2 ); |
| |
| silk_corrMatrix_FLP( lag_ptr, subfr_length, LTP_ORDER, WLTP_ptr ); |
| silk_corrVector_FLP( lag_ptr, r_ptr, subfr_length, LTP_ORDER, Rr ); |
| |
| rr[ k ] = ( silk_float )silk_energy_FLP( r_ptr, subfr_length ); |
| regu = 1.0f + rr[ k ] + |
| matrix_ptr( WLTP_ptr, 0, 0, LTP_ORDER ) + |
| matrix_ptr( WLTP_ptr, LTP_ORDER-1, LTP_ORDER-1, LTP_ORDER ); |
| regu *= LTP_DAMPING / 3; |
| silk_regularize_correlations_FLP( WLTP_ptr, &rr[ k ], regu, LTP_ORDER ); |
| silk_solve_LDL_FLP( WLTP_ptr, LTP_ORDER, Rr, b_ptr ); |
| |
| /* Calculate residual energy */ |
| nrg[ k ] = silk_residual_energy_covar_FLP( b_ptr, WLTP_ptr, Rr, rr[ k ], LTP_ORDER ); |
| |
| temp = Wght[ k ] / ( nrg[ k ] * Wght[ k ] + 0.01f * subfr_length ); |
| silk_scale_vector_FLP( WLTP_ptr, temp, LTP_ORDER * LTP_ORDER ); |
| w[ k ] = matrix_ptr( WLTP_ptr, LTP_ORDER / 2, LTP_ORDER / 2, LTP_ORDER ); |
| |
| r_ptr += subfr_length; |
| b_ptr += LTP_ORDER; |
| WLTP_ptr += LTP_ORDER * LTP_ORDER; |
| } |
| |
| /* Compute LTP coding gain */ |
| if( LTPredCodGain != NULL ) { |
| LPC_LTP_res_nrg = 1e-6f; |
| LPC_res_nrg = 0.0f; |
| for( k = 0; k < nb_subfr; k++ ) { |
| LPC_res_nrg += rr[ k ] * Wght[ k ]; |
| LPC_LTP_res_nrg += nrg[ k ] * Wght[ k ]; |
| } |
| |
| silk_assert( LPC_LTP_res_nrg > 0 ); |
| *LTPredCodGain = 3.0f * silk_log2( LPC_res_nrg / LPC_LTP_res_nrg ); |
| } |
| |
| /* Smoothing */ |
| /* d = sum( B, 1 ); */ |
| b_ptr = b; |
| for( k = 0; k < nb_subfr; k++ ) { |
| d[ k ] = 0; |
| for( i = 0; i < LTP_ORDER; i++ ) { |
| d[ k ] += b_ptr[ i ]; |
| } |
| b_ptr += LTP_ORDER; |
| } |
| /* m = ( w * d' ) / ( sum( w ) + 1e-3 ); */ |
| temp = 1e-3f; |
| for( k = 0; k < nb_subfr; k++ ) { |
| temp += w[ k ]; |
| } |
| m = 0; |
| for( k = 0; k < nb_subfr; k++ ) { |
| m += d[ k ] * w[ k ]; |
| } |
| m = m / temp; |
| |
| b_ptr = b; |
| for( k = 0; k < nb_subfr; k++ ) { |
| g = LTP_SMOOTHING / ( LTP_SMOOTHING + w[ k ] ) * ( m - d[ k ] ); |
| temp = 0; |
| for( i = 0; i < LTP_ORDER; i++ ) { |
| delta_b[ i ] = silk_max_float( b_ptr[ i ], 0.1f ); |
| temp += delta_b[ i ]; |
| } |
| temp = g / temp; |
| for( i = 0; i < LTP_ORDER; i++ ) { |
| b_ptr[ i ] = b_ptr[ i ] + delta_b[ i ] * temp; |
| } |
| b_ptr += LTP_ORDER; |
| } |
| } |