Add copy of opus library in deps/third_party.

opus/silk/float/find_LTP_FLP.c

+/***********************************************************************
+Copyright (c) 2006-2011, Skype Limited. All rights reserved.
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+- Redistributions of source code must retain the above copyright notice,
+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 
+names of specific contributors, may be used to endorse or promote
+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
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+***********************************************************************/
+
+#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;
+    }
+}