Chris@69: /*********************************************************************** Chris@69: Copyright (c) 2006-2011, Skype Limited. All rights reserved. Chris@69: Redistribution and use in source and binary forms, with or without Chris@69: modification, are permitted provided that the following conditions Chris@69: are met: Chris@69: - Redistributions of source code must retain the above copyright notice, Chris@69: this list of conditions and the following disclaimer. Chris@69: - Redistributions in binary form must reproduce the above copyright Chris@69: notice, this list of conditions and the following disclaimer in the Chris@69: documentation and/or other materials provided with the distribution. Chris@69: - Neither the name of Internet Society, IETF or IETF Trust, nor the Chris@69: names of specific contributors, may be used to endorse or promote Chris@69: products derived from this software without specific prior written Chris@69: permission. Chris@69: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" Chris@69: AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE Chris@69: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE Chris@69: ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE Chris@69: LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR Chris@69: CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF Chris@69: SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS Chris@69: INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN Chris@69: CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) Chris@69: ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE Chris@69: POSSIBILITY OF SUCH DAMAGE. Chris@69: ***********************************************************************/ Chris@69: Chris@69: #ifdef HAVE_CONFIG_H Chris@69: #include "config.h" Chris@69: #endif Chris@69: Chris@69: #include "define.h" Chris@69: #include "main_FLP.h" Chris@69: #include "tuning_parameters.h" Chris@69: Chris@69: /* LPC analysis */ Chris@69: void silk_find_LPC_FLP( Chris@69: silk_encoder_state *psEncC, /* I/O Encoder state */ Chris@69: opus_int16 NLSF_Q15[], /* O NLSFs */ Chris@69: const silk_float x[], /* I Input signal */ Chris@69: const silk_float minInvGain /* I Inverse of max prediction gain */ Chris@69: ) Chris@69: { Chris@69: opus_int k, subfr_length; Chris@69: silk_float a[ MAX_LPC_ORDER ]; Chris@69: Chris@69: /* Used only for NLSF interpolation */ Chris@69: silk_float res_nrg, res_nrg_2nd, res_nrg_interp; Chris@69: opus_int16 NLSF0_Q15[ MAX_LPC_ORDER ]; Chris@69: silk_float a_tmp[ MAX_LPC_ORDER ]; Chris@69: silk_float LPC_res[ MAX_FRAME_LENGTH + MAX_NB_SUBFR * MAX_LPC_ORDER ]; Chris@69: Chris@69: subfr_length = psEncC->subfr_length + psEncC->predictLPCOrder; Chris@69: Chris@69: /* Default: No interpolation */ Chris@69: psEncC->indices.NLSFInterpCoef_Q2 = 4; Chris@69: Chris@69: /* Burg AR analysis for the full frame */ Chris@69: res_nrg = silk_burg_modified_FLP( a, x, minInvGain, subfr_length, psEncC->nb_subfr, psEncC->predictLPCOrder ); Chris@69: Chris@69: if( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) { Chris@69: /* Optimal solution for last 10 ms; subtract residual energy here, as that's easier than */ Chris@69: /* adding it to the residual energy of the first 10 ms in each iteration of the search below */ Chris@69: res_nrg -= silk_burg_modified_FLP( a_tmp, x + ( MAX_NB_SUBFR / 2 ) * subfr_length, minInvGain, subfr_length, MAX_NB_SUBFR / 2, psEncC->predictLPCOrder ); Chris@69: Chris@69: /* Convert to NLSFs */ Chris@69: silk_A2NLSF_FLP( NLSF_Q15, a_tmp, psEncC->predictLPCOrder ); Chris@69: Chris@69: /* Search over interpolation indices to find the one with lowest residual energy */ Chris@69: res_nrg_2nd = silk_float_MAX; Chris@69: for( k = 3; k >= 0; k-- ) { Chris@69: /* Interpolate NLSFs for first half */ Chris@69: silk_interpolate( NLSF0_Q15, psEncC->prev_NLSFq_Q15, NLSF_Q15, k, psEncC->predictLPCOrder ); Chris@69: Chris@69: /* Convert to LPC for residual energy evaluation */ Chris@69: silk_NLSF2A_FLP( a_tmp, NLSF0_Q15, psEncC->predictLPCOrder, psEncC->arch ); Chris@69: Chris@69: /* Calculate residual energy with LSF interpolation */ Chris@69: silk_LPC_analysis_filter_FLP( LPC_res, a_tmp, x, 2 * subfr_length, psEncC->predictLPCOrder ); Chris@69: res_nrg_interp = (silk_float)( Chris@69: silk_energy_FLP( LPC_res + psEncC->predictLPCOrder, subfr_length - psEncC->predictLPCOrder ) + Chris@69: silk_energy_FLP( LPC_res + psEncC->predictLPCOrder + subfr_length, subfr_length - psEncC->predictLPCOrder ) ); Chris@69: Chris@69: /* Determine whether current interpolated NLSFs are best so far */ Chris@69: if( res_nrg_interp < res_nrg ) { Chris@69: /* Interpolation has lower residual energy */ Chris@69: res_nrg = res_nrg_interp; Chris@69: psEncC->indices.NLSFInterpCoef_Q2 = (opus_int8)k; Chris@69: } else if( res_nrg_interp > res_nrg_2nd ) { Chris@69: /* No reason to continue iterating - residual energies will continue to climb */ Chris@69: break; Chris@69: } Chris@69: res_nrg_2nd = res_nrg_interp; Chris@69: } Chris@69: } Chris@69: Chris@69: if( psEncC->indices.NLSFInterpCoef_Q2 == 4 ) { Chris@69: /* NLSF interpolation is currently inactive, calculate NLSFs from full frame AR coefficients */ Chris@69: silk_A2NLSF_FLP( NLSF_Q15, a, psEncC->predictLPCOrder ); Chris@69: } Chris@69: Chris@69: celt_assert( psEncC->indices.NLSFInterpCoef_Q2 == 4 || Chris@69: ( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) ); Chris@69: }