mirror of
https://github.com/UberGames/lilium-voyager.git
synced 2024-12-15 06:30:49 +00:00
104 lines
5.3 KiB
C
104 lines
5.3 KiB
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 "define.h"
|
|
#include "main_FLP.h"
|
|
#include "tuning_parameters.h"
|
|
|
|
/* LPC analysis */
|
|
void silk_find_LPC_FLP(
|
|
silk_encoder_state *psEncC, /* I/O Encoder state */
|
|
opus_int16 NLSF_Q15[], /* O NLSFs */
|
|
const silk_float x[], /* I Input signal */
|
|
const silk_float minInvGain /* I Inverse of max prediction gain */
|
|
)
|
|
{
|
|
opus_int k, subfr_length;
|
|
silk_float a[ MAX_LPC_ORDER ];
|
|
|
|
/* Used only for NLSF interpolation */
|
|
silk_float res_nrg, res_nrg_2nd, res_nrg_interp;
|
|
opus_int16 NLSF0_Q15[ MAX_LPC_ORDER ];
|
|
silk_float a_tmp[ MAX_LPC_ORDER ];
|
|
silk_float LPC_res[ MAX_FRAME_LENGTH + MAX_NB_SUBFR * MAX_LPC_ORDER ];
|
|
|
|
subfr_length = psEncC->subfr_length + psEncC->predictLPCOrder;
|
|
|
|
/* Default: No interpolation */
|
|
psEncC->indices.NLSFInterpCoef_Q2 = 4;
|
|
|
|
/* Burg AR analysis for the full frame */
|
|
res_nrg = silk_burg_modified_FLP( a, x, minInvGain, subfr_length, psEncC->nb_subfr, psEncC->predictLPCOrder );
|
|
|
|
if( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) {
|
|
/* Optimal solution for last 10 ms; subtract residual energy here, as that's easier than */
|
|
/* adding it to the residual energy of the first 10 ms in each iteration of the search below */
|
|
res_nrg -= silk_burg_modified_FLP( a_tmp, x + ( MAX_NB_SUBFR / 2 ) * subfr_length, minInvGain, subfr_length, MAX_NB_SUBFR / 2, psEncC->predictLPCOrder );
|
|
|
|
/* Convert to NLSFs */
|
|
silk_A2NLSF_FLP( NLSF_Q15, a_tmp, psEncC->predictLPCOrder );
|
|
|
|
/* Search over interpolation indices to find the one with lowest residual energy */
|
|
res_nrg_2nd = silk_float_MAX;
|
|
for( k = 3; k >= 0; k-- ) {
|
|
/* Interpolate NLSFs for first half */
|
|
silk_interpolate( NLSF0_Q15, psEncC->prev_NLSFq_Q15, NLSF_Q15, k, psEncC->predictLPCOrder );
|
|
|
|
/* Convert to LPC for residual energy evaluation */
|
|
silk_NLSF2A_FLP( a_tmp, NLSF0_Q15, psEncC->predictLPCOrder, psEncC->arch );
|
|
|
|
/* Calculate residual energy with LSF interpolation */
|
|
silk_LPC_analysis_filter_FLP( LPC_res, a_tmp, x, 2 * subfr_length, psEncC->predictLPCOrder );
|
|
res_nrg_interp = (silk_float)(
|
|
silk_energy_FLP( LPC_res + psEncC->predictLPCOrder, subfr_length - psEncC->predictLPCOrder ) +
|
|
silk_energy_FLP( LPC_res + psEncC->predictLPCOrder + subfr_length, subfr_length - psEncC->predictLPCOrder ) );
|
|
|
|
/* Determine whether current interpolated NLSFs are best so far */
|
|
if( res_nrg_interp < res_nrg ) {
|
|
/* Interpolation has lower residual energy */
|
|
res_nrg = res_nrg_interp;
|
|
psEncC->indices.NLSFInterpCoef_Q2 = (opus_int8)k;
|
|
} else if( res_nrg_interp > res_nrg_2nd ) {
|
|
/* No reason to continue iterating - residual energies will continue to climb */
|
|
break;
|
|
}
|
|
res_nrg_2nd = res_nrg_interp;
|
|
}
|
|
}
|
|
|
|
if( psEncC->indices.NLSFInterpCoef_Q2 == 4 ) {
|
|
/* NLSF interpolation is currently inactive, calculate NLSFs from full frame AR coefficients */
|
|
silk_A2NLSF_FLP( NLSF_Q15, a, psEncC->predictLPCOrder );
|
|
}
|
|
|
|
silk_assert( psEncC->indices.NLSFInterpCoef_Q2 == 4 ||
|
|
( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) );
|
|
}
|