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 "main_FIX.h" Chris@69: #include "stack_alloc.h" Chris@69: #include "tuning_parameters.h" Chris@69: Chris@69: /* Finds LPC vector from correlations, and converts to NLSF */ Chris@69: void silk_find_LPC_FIX( Chris@69: silk_encoder_state *psEncC, /* I/O Encoder state */ Chris@69: opus_int16 NLSF_Q15[], /* O NLSFs */ Chris@69: const opus_int16 x[], /* I Input signal */ Chris@69: const opus_int32 minInvGain_Q30 /* I Inverse of max prediction gain */ Chris@69: ) Chris@69: { Chris@69: opus_int k, subfr_length; Chris@69: opus_int32 a_Q16[ MAX_LPC_ORDER ]; Chris@69: opus_int isInterpLower, shift; Chris@69: opus_int32 res_nrg0, res_nrg1; Chris@69: opus_int rshift0, rshift1; Chris@69: Chris@69: /* Used only for LSF interpolation */ Chris@69: opus_int32 a_tmp_Q16[ MAX_LPC_ORDER ], res_nrg_interp, res_nrg, res_tmp_nrg; Chris@69: opus_int res_nrg_interp_Q, res_nrg_Q, res_tmp_nrg_Q; Chris@69: opus_int16 a_tmp_Q12[ MAX_LPC_ORDER ]; Chris@69: opus_int16 NLSF0_Q15[ MAX_LPC_ORDER ]; Chris@69: SAVE_STACK; 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: silk_burg_modified( &res_nrg, &res_nrg_Q, a_Q16, x, minInvGain_Q30, subfr_length, psEncC->nb_subfr, psEncC->predictLPCOrder, psEncC->arch ); Chris@69: Chris@69: if( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) { Chris@69: VARDECL( opus_int16, LPC_res ); Chris@69: Chris@69: /* Optimal solution for last 10 ms */ Chris@69: silk_burg_modified( &res_tmp_nrg, &res_tmp_nrg_Q, a_tmp_Q16, x + 2 * subfr_length, minInvGain_Q30, subfr_length, 2, psEncC->predictLPCOrder, psEncC->arch ); Chris@69: Chris@69: /* subtract residual energy here, as that's easier than adding it to the */ Chris@69: /* residual energy of the first 10 ms in each iteration of the search below */ Chris@69: shift = res_tmp_nrg_Q - res_nrg_Q; Chris@69: if( shift >= 0 ) { Chris@69: if( shift < 32 ) { Chris@69: res_nrg = res_nrg - silk_RSHIFT( res_tmp_nrg, shift ); Chris@69: } Chris@69: } else { Chris@69: silk_assert( shift > -32 ); Chris@69: res_nrg = silk_RSHIFT( res_nrg, -shift ) - res_tmp_nrg; Chris@69: res_nrg_Q = res_tmp_nrg_Q; Chris@69: } Chris@69: Chris@69: /* Convert to NLSFs */ Chris@69: silk_A2NLSF( NLSF_Q15, a_tmp_Q16, psEncC->predictLPCOrder ); Chris@69: Chris@69: ALLOC( LPC_res, 2 * subfr_length, opus_int16 ); Chris@69: Chris@69: /* Search over interpolation indices to find the one with lowest residual energy */ 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( a_tmp_Q12, NLSF0_Q15, psEncC->predictLPCOrder, psEncC->arch ); Chris@69: Chris@69: /* Calculate residual energy with NLSF interpolation */ Chris@69: silk_LPC_analysis_filter( LPC_res, x, a_tmp_Q12, 2 * subfr_length, psEncC->predictLPCOrder, psEncC->arch ); Chris@69: Chris@69: silk_sum_sqr_shift( &res_nrg0, &rshift0, LPC_res + psEncC->predictLPCOrder, subfr_length - psEncC->predictLPCOrder ); Chris@69: silk_sum_sqr_shift( &res_nrg1, &rshift1, LPC_res + psEncC->predictLPCOrder + subfr_length, subfr_length - psEncC->predictLPCOrder ); Chris@69: Chris@69: /* Add subframe energies from first half frame */ Chris@69: shift = rshift0 - rshift1; Chris@69: if( shift >= 0 ) { Chris@69: res_nrg1 = silk_RSHIFT( res_nrg1, shift ); Chris@69: res_nrg_interp_Q = -rshift0; Chris@69: } else { Chris@69: res_nrg0 = silk_RSHIFT( res_nrg0, -shift ); Chris@69: res_nrg_interp_Q = -rshift1; Chris@69: } Chris@69: res_nrg_interp = silk_ADD32( res_nrg0, res_nrg1 ); Chris@69: Chris@69: /* Compare with first half energy without NLSF interpolation, or best interpolated value so far */ Chris@69: shift = res_nrg_interp_Q - res_nrg_Q; Chris@69: if( shift >= 0 ) { Chris@69: if( silk_RSHIFT( res_nrg_interp, shift ) < res_nrg ) { Chris@69: isInterpLower = silk_TRUE; Chris@69: } else { Chris@69: isInterpLower = silk_FALSE; Chris@69: } Chris@69: } else { Chris@69: if( -shift < 32 ) { Chris@69: if( res_nrg_interp < silk_RSHIFT( res_nrg, -shift ) ) { Chris@69: isInterpLower = silk_TRUE; Chris@69: } else { Chris@69: isInterpLower = silk_FALSE; Chris@69: } Chris@69: } else { Chris@69: isInterpLower = silk_FALSE; Chris@69: } Chris@69: } Chris@69: Chris@69: /* Determine whether current interpolated NLSFs are best so far */ Chris@69: if( isInterpLower == silk_TRUE ) { Chris@69: /* Interpolation has lower residual energy */ Chris@69: res_nrg = res_nrg_interp; Chris@69: res_nrg_Q = res_nrg_interp_Q; Chris@69: psEncC->indices.NLSFInterpCoef_Q2 = (opus_int8)k; Chris@69: } 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( NLSF_Q15, a_Q16, psEncC->predictLPCOrder ); Chris@69: } Chris@69: Chris@69: celt_assert( psEncC->indices.NLSFInterpCoef_Q2 == 4 || ( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) ); Chris@69: RESTORE_STACK; Chris@69: }