michael@0: /*********************************************************************** michael@0: Copyright (c) 2006-2011, Skype Limited. All rights reserved. michael@0: Redistribution and use in source and binary forms, with or without michael@0: modification, are permitted provided that the following conditions michael@0: are met: michael@0: - Redistributions of source code must retain the above copyright notice, michael@0: this list of conditions and the following disclaimer. michael@0: - Redistributions in binary form must reproduce the above copyright michael@0: notice, this list of conditions and the following disclaimer in the michael@0: documentation and/or other materials provided with the distribution. michael@0: - Neither the name of Internet Society, IETF or IETF Trust, nor the michael@0: names of specific contributors, may be used to endorse or promote michael@0: products derived from this software without specific prior written michael@0: permission. michael@0: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" michael@0: AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE michael@0: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE michael@0: ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE michael@0: LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR michael@0: CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF michael@0: SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS michael@0: INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN michael@0: CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) michael@0: ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE michael@0: POSSIBILITY OF SUCH DAMAGE. michael@0: ***********************************************************************/ michael@0: michael@0: #ifdef HAVE_CONFIG_H michael@0: #include "config.h" michael@0: #endif michael@0: michael@0: #include "main_FIX.h" michael@0: #include "stack_alloc.h" michael@0: #include "tuning_parameters.h" michael@0: michael@0: /* Finds LPC vector from correlations, and converts to NLSF */ michael@0: void silk_find_LPC_FIX( michael@0: silk_encoder_state *psEncC, /* I/O Encoder state */ michael@0: opus_int16 NLSF_Q15[], /* O NLSFs */ michael@0: const opus_int16 x[], /* I Input signal */ michael@0: const opus_int32 minInvGain_Q30 /* I Inverse of max prediction gain */ michael@0: ) michael@0: { michael@0: opus_int k, subfr_length; michael@0: opus_int32 a_Q16[ MAX_LPC_ORDER ]; michael@0: opus_int isInterpLower, shift; michael@0: opus_int32 res_nrg0, res_nrg1; michael@0: opus_int rshift0, rshift1; michael@0: michael@0: /* Used only for LSF interpolation */ michael@0: opus_int32 a_tmp_Q16[ MAX_LPC_ORDER ], res_nrg_interp, res_nrg, res_tmp_nrg; michael@0: opus_int res_nrg_interp_Q, res_nrg_Q, res_tmp_nrg_Q; michael@0: opus_int16 a_tmp_Q12[ MAX_LPC_ORDER ]; michael@0: opus_int16 NLSF0_Q15[ MAX_LPC_ORDER ]; michael@0: SAVE_STACK; michael@0: michael@0: subfr_length = psEncC->subfr_length + psEncC->predictLPCOrder; michael@0: michael@0: /* Default: no interpolation */ michael@0: psEncC->indices.NLSFInterpCoef_Q2 = 4; michael@0: michael@0: /* Burg AR analysis for the full frame */ michael@0: silk_burg_modified( &res_nrg, &res_nrg_Q, a_Q16, x, minInvGain_Q30, subfr_length, psEncC->nb_subfr, psEncC->predictLPCOrder, psEncC->arch ); michael@0: michael@0: if( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) { michael@0: VARDECL( opus_int16, LPC_res ); michael@0: michael@0: /* Optimal solution for last 10 ms */ michael@0: 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 ); michael@0: michael@0: /* subtract residual energy here, as that's easier than adding it to the */ michael@0: /* residual energy of the first 10 ms in each iteration of the search below */ michael@0: shift = res_tmp_nrg_Q - res_nrg_Q; michael@0: if( shift >= 0 ) { michael@0: if( shift < 32 ) { michael@0: res_nrg = res_nrg - silk_RSHIFT( res_tmp_nrg, shift ); michael@0: } michael@0: } else { michael@0: silk_assert( shift > -32 ); michael@0: res_nrg = silk_RSHIFT( res_nrg, -shift ) - res_tmp_nrg; michael@0: res_nrg_Q = res_tmp_nrg_Q; michael@0: } michael@0: michael@0: /* Convert to NLSFs */ michael@0: silk_A2NLSF( NLSF_Q15, a_tmp_Q16, psEncC->predictLPCOrder ); michael@0: michael@0: ALLOC( LPC_res, 2 * subfr_length, opus_int16 ); michael@0: michael@0: /* Search over interpolation indices to find the one with lowest residual energy */ michael@0: for( k = 3; k >= 0; k-- ) { michael@0: /* Interpolate NLSFs for first half */ michael@0: silk_interpolate( NLSF0_Q15, psEncC->prev_NLSFq_Q15, NLSF_Q15, k, psEncC->predictLPCOrder ); michael@0: michael@0: /* Convert to LPC for residual energy evaluation */ michael@0: silk_NLSF2A( a_tmp_Q12, NLSF0_Q15, psEncC->predictLPCOrder ); michael@0: michael@0: /* Calculate residual energy with NLSF interpolation */ michael@0: silk_LPC_analysis_filter( LPC_res, x, a_tmp_Q12, 2 * subfr_length, psEncC->predictLPCOrder ); michael@0: michael@0: silk_sum_sqr_shift( &res_nrg0, &rshift0, LPC_res + psEncC->predictLPCOrder, subfr_length - psEncC->predictLPCOrder ); michael@0: silk_sum_sqr_shift( &res_nrg1, &rshift1, LPC_res + psEncC->predictLPCOrder + subfr_length, subfr_length - psEncC->predictLPCOrder ); michael@0: michael@0: /* Add subframe energies from first half frame */ michael@0: shift = rshift0 - rshift1; michael@0: if( shift >= 0 ) { michael@0: res_nrg1 = silk_RSHIFT( res_nrg1, shift ); michael@0: res_nrg_interp_Q = -rshift0; michael@0: } else { michael@0: res_nrg0 = silk_RSHIFT( res_nrg0, -shift ); michael@0: res_nrg_interp_Q = -rshift1; michael@0: } michael@0: res_nrg_interp = silk_ADD32( res_nrg0, res_nrg1 ); michael@0: michael@0: /* Compare with first half energy without NLSF interpolation, or best interpolated value so far */ michael@0: shift = res_nrg_interp_Q - res_nrg_Q; michael@0: if( shift >= 0 ) { michael@0: if( silk_RSHIFT( res_nrg_interp, shift ) < res_nrg ) { michael@0: isInterpLower = silk_TRUE; michael@0: } else { michael@0: isInterpLower = silk_FALSE; michael@0: } michael@0: } else { michael@0: if( -shift < 32 ) { michael@0: if( res_nrg_interp < silk_RSHIFT( res_nrg, -shift ) ) { michael@0: isInterpLower = silk_TRUE; michael@0: } else { michael@0: isInterpLower = silk_FALSE; michael@0: } michael@0: } else { michael@0: isInterpLower = silk_FALSE; michael@0: } michael@0: } michael@0: michael@0: /* Determine whether current interpolated NLSFs are best so far */ michael@0: if( isInterpLower == silk_TRUE ) { michael@0: /* Interpolation has lower residual energy */ michael@0: res_nrg = res_nrg_interp; michael@0: res_nrg_Q = res_nrg_interp_Q; michael@0: psEncC->indices.NLSFInterpCoef_Q2 = (opus_int8)k; michael@0: } michael@0: } michael@0: } michael@0: michael@0: if( psEncC->indices.NLSFInterpCoef_Q2 == 4 ) { michael@0: /* NLSF interpolation is currently inactive, calculate NLSFs from full frame AR coefficients */ michael@0: silk_A2NLSF( NLSF_Q15, a_Q16, psEncC->predictLPCOrder ); michael@0: } michael@0: michael@0: silk_assert( psEncC->indices.NLSFInterpCoef_Q2 == 4 || ( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) ); michael@0: RESTORE_STACK; michael@0: }