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/***********************************************************************
Copyright (c) 2006-2011, Skype Limited. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, (subject to the limitations in the disclaimer below)
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 Skype Limited, nor the names of specific
contributors, may be used to endorse or promote products derived from
this software without specific prior written permission.
NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED
BY THIS LICENSE. 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.
***********************************************************************/
#include "SKP_Silk_main_FLP.h"
#define MAX_ITERATIONS_RESIDUAL_NRG 10
#define REGULARIZATION_FACTOR 1e-8f
/* Residual energy: nrg = wxx - 2 * wXx * c + c' * wXX * c */
SKP_float SKP_Silk_residual_energy_covar_FLP( /* O Weighted residual energy */
const SKP_float *c, /* I Filter coefficients */
SKP_float *wXX, /* I/O Weighted correlation matrix, reg. out */
const SKP_float *wXx, /* I Weighted correlation vector */
const SKP_float wxx, /* I Weighted correlation value */
const SKP_int D /* I Dimension */
)
{
SKP_int i, j, k;
SKP_float tmp, nrg, regularization;
/* Safety checks */
SKP_assert( D >= 0 );
regularization = REGULARIZATION_FACTOR * ( wXX[ 0 ] + wXX[ D * D - 1 ] );
for( k = 0; k < MAX_ITERATIONS_RESIDUAL_NRG; k++ ) {
nrg = wxx;
tmp = 0.0f;
for( i = 0; i < D; i++ ) {
tmp += wXx[ i ] * c[ i ];
}
nrg -= 2.0f * tmp;
/* compute c' * wXX * c, assuming wXX is symmetric */
for( i = 0; i < D; i++ ) {
tmp = 0.0f;
for( j = i + 1; j < D; j++ ) {
tmp += matrix_c_ptr( wXX, i, j, D ) * c[ j ];
}
nrg += c[ i ] * ( 2.0f * tmp + matrix_c_ptr( wXX, i, i, D ) * c[ i ] );
}
if( nrg > 0 ) {
break;
} else {
/* Add white noise */
for( i = 0; i < D; i++ ) {
matrix_c_ptr( wXX, i, i, D ) += regularization;
}
/* Increase noise for next run */
regularization *= 2.0f;
}
}
if( k == MAX_ITERATIONS_RESIDUAL_NRG ) {
SKP_assert( nrg == 0 );
nrg = 1.0f;
}
return nrg;
}
/* Calculates residual energies of input subframes where all subframes have LPC_order */
/* of preceeding samples */
void SKP_Silk_residual_energy_FLP(
SKP_float nrgs[ MAX_NB_SUBFR ], /* O Residual energy per subframe */
const SKP_float x[], /* I Input signal */
const SKP_float a[ 2 ][ MAX_LPC_ORDER ], /* I AR coefs for each frame half */
const SKP_float gains[], /* I Quantization gains */
const SKP_int subfr_length, /* I Subframe length */
const SKP_int nb_subfr, /* I number of subframes */
const SKP_int LPC_order /* I LPC order */
)
{
SKP_int shift;
SKP_float *LPC_res_ptr, LPC_res[ ( MAX_FRAME_LENGTH + MAX_NB_SUBFR * MAX_LPC_ORDER ) / 2 ];
LPC_res_ptr = LPC_res + LPC_order;
shift = LPC_order + subfr_length;
/* Filter input to create the LPC residual for each frame half, and measure subframe energies */
SKP_Silk_LPC_analysis_filter_FLP( LPC_res, a[ 0 ], x + 0 * shift, 2 * shift, LPC_order );
nrgs[ 0 ] = ( SKP_float )( gains[ 0 ] * gains[ 0 ] * SKP_Silk_energy_FLP( LPC_res_ptr + 0 * shift, subfr_length ) );
nrgs[ 1 ] = ( SKP_float )( gains[ 1 ] * gains[ 1 ] * SKP_Silk_energy_FLP( LPC_res_ptr + 1 * shift, subfr_length ) );
if( nb_subfr == MAX_NB_SUBFR ) {
SKP_Silk_LPC_analysis_filter_FLP( LPC_res, a[ 1 ], x + 2 * shift, 2 * shift, LPC_order );
nrgs[ 2 ] = ( SKP_float )( gains[ 2 ] * gains[ 2 ] * SKP_Silk_energy_FLP( LPC_res_ptr + 0 * shift, subfr_length ) );
nrgs[ 3 ] = ( SKP_float )( gains[ 3 ] * gains[ 3 ] * SKP_Silk_energy_FLP( LPC_res_ptr + 1 * shift, subfr_length ) );
}
}
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