| /*********************************************************************** |
| 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 |
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| 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_FIX.h" |
| #include "stack_alloc.h" |
| #include "tuning_parameters.h" |
| |
| /* Finds LPC vector from correlations, and converts to NLSF */ |
| void silk_find_LPC_FIX( |
| silk_encoder_state *psEncC, /* I/O Encoder state */ |
| opus_int16 NLSF_Q15[], /* O NLSFs */ |
| const opus_int16 x[], /* I Input signal */ |
| const opus_int32 minInvGain_Q30 /* I Inverse of max prediction gain */ |
| ) |
| { |
| opus_int k, subfr_length; |
| opus_int32 a_Q16[ MAX_LPC_ORDER ]; |
| opus_int isInterpLower, shift; |
| opus_int32 res_nrg0, res_nrg1; |
| opus_int rshift0, rshift1; |
| |
| /* Used only for LSF interpolation */ |
| opus_int32 a_tmp_Q16[ MAX_LPC_ORDER ], res_nrg_interp, res_nrg, res_tmp_nrg; |
| opus_int res_nrg_interp_Q, res_nrg_Q, res_tmp_nrg_Q; |
| opus_int16 a_tmp_Q12[ MAX_LPC_ORDER ]; |
| opus_int16 NLSF0_Q15[ MAX_LPC_ORDER ]; |
| SAVE_STACK; |
| |
| subfr_length = psEncC->subfr_length + psEncC->predictLPCOrder; |
| |
| /* Default: no interpolation */ |
| psEncC->indices.NLSFInterpCoef_Q2 = 4; |
| |
| /* Burg AR analysis for the full frame */ |
| silk_burg_modified( &res_nrg, &res_nrg_Q, a_Q16, x, minInvGain_Q30, subfr_length, psEncC->nb_subfr, psEncC->predictLPCOrder, psEncC->arch ); |
| |
| if( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) { |
| VARDECL( opus_int16, LPC_res ); |
| |
| /* Optimal solution for last 10 ms */ |
| 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 ); |
| |
| /* 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 */ |
| shift = res_tmp_nrg_Q - res_nrg_Q; |
| if( shift >= 0 ) { |
| if( shift < 32 ) { |
| res_nrg = res_nrg - silk_RSHIFT( res_tmp_nrg, shift ); |
| } |
| } else { |
| silk_assert( shift > -32 ); |
| res_nrg = silk_RSHIFT( res_nrg, -shift ) - res_tmp_nrg; |
| res_nrg_Q = res_tmp_nrg_Q; |
| } |
| |
| /* Convert to NLSFs */ |
| silk_A2NLSF( NLSF_Q15, a_tmp_Q16, psEncC->predictLPCOrder ); |
| |
| ALLOC( LPC_res, 2 * subfr_length, opus_int16 ); |
| |
| /* Search over interpolation indices to find the one with lowest residual energy */ |
| 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( a_tmp_Q12, NLSF0_Q15, psEncC->predictLPCOrder, psEncC->arch ); |
| |
| /* Calculate residual energy with NLSF interpolation */ |
| silk_LPC_analysis_filter( LPC_res, x, a_tmp_Q12, 2 * subfr_length, psEncC->predictLPCOrder, psEncC->arch ); |
| |
| silk_sum_sqr_shift( &res_nrg0, &rshift0, LPC_res + psEncC->predictLPCOrder, subfr_length - psEncC->predictLPCOrder ); |
| silk_sum_sqr_shift( &res_nrg1, &rshift1, LPC_res + psEncC->predictLPCOrder + subfr_length, subfr_length - psEncC->predictLPCOrder ); |
| |
| /* Add subframe energies from first half frame */ |
| shift = rshift0 - rshift1; |
| if( shift >= 0 ) { |
| res_nrg1 = silk_RSHIFT( res_nrg1, shift ); |
| res_nrg_interp_Q = -rshift0; |
| } else { |
| res_nrg0 = silk_RSHIFT( res_nrg0, -shift ); |
| res_nrg_interp_Q = -rshift1; |
| } |
| res_nrg_interp = silk_ADD32( res_nrg0, res_nrg1 ); |
| |
| /* Compare with first half energy without NLSF interpolation, or best interpolated value so far */ |
| shift = res_nrg_interp_Q - res_nrg_Q; |
| if( shift >= 0 ) { |
| if( silk_RSHIFT( res_nrg_interp, shift ) < res_nrg ) { |
| isInterpLower = silk_TRUE; |
| } else { |
| isInterpLower = silk_FALSE; |
| } |
| } else { |
| if( -shift < 32 ) { |
| if( res_nrg_interp < silk_RSHIFT( res_nrg, -shift ) ) { |
| isInterpLower = silk_TRUE; |
| } else { |
| isInterpLower = silk_FALSE; |
| } |
| } else { |
| isInterpLower = silk_FALSE; |
| } |
| } |
| |
| /* Determine whether current interpolated NLSFs are best so far */ |
| if( isInterpLower == silk_TRUE ) { |
| /* Interpolation has lower residual energy */ |
| res_nrg = res_nrg_interp; |
| res_nrg_Q = res_nrg_interp_Q; |
| psEncC->indices.NLSFInterpCoef_Q2 = (opus_int8)k; |
| } |
| } |
| } |
| |
| if( psEncC->indices.NLSFInterpCoef_Q2 == 4 ) { |
| /* NLSF interpolation is currently inactive, calculate NLSFs from full frame AR coefficients */ |
| silk_A2NLSF( NLSF_Q15, a_Q16, psEncC->predictLPCOrder ); |
| } |
| |
| celt_assert( psEncC->indices.NLSFInterpCoef_Q2 == 4 || ( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) ); |
| RESTORE_STACK; |
| } |
