1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/media/libopus/silk/fixed/find_LPC_FIX.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,151 @@
1.4 +/***********************************************************************
1.5 +Copyright (c) 2006-2011, Skype Limited. All rights reserved.
1.6 +Redistribution and use in source and binary forms, with or without
1.7 +modification, are permitted provided that the following conditions
1.8 +are met:
1.9 +- Redistributions of source code must retain the above copyright notice,
1.10 +this list of conditions and the following disclaimer.
1.11 +- Redistributions in binary form must reproduce the above copyright
1.12 +notice, this list of conditions and the following disclaimer in the
1.13 +documentation and/or other materials provided with the distribution.
1.14 +- Neither the name of Internet Society, IETF or IETF Trust, nor the
1.15 +names of specific contributors, may be used to endorse or promote
1.16 +products derived from this software without specific prior written
1.17 +permission.
1.18 +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
1.19 +AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1.20 +IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1.21 +ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
1.22 +LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
1.23 +CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
1.24 +SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
1.25 +INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
1.26 +CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
1.27 +ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
1.28 +POSSIBILITY OF SUCH DAMAGE.
1.29 +***********************************************************************/
1.30 +
1.31 +#ifdef HAVE_CONFIG_H
1.32 +#include "config.h"
1.33 +#endif
1.34 +
1.35 +#include "main_FIX.h"
1.36 +#include "stack_alloc.h"
1.37 +#include "tuning_parameters.h"
1.38 +
1.39 +/* Finds LPC vector from correlations, and converts to NLSF */
1.40 +void silk_find_LPC_FIX(
1.41 + silk_encoder_state *psEncC, /* I/O Encoder state */
1.42 + opus_int16 NLSF_Q15[], /* O NLSFs */
1.43 + const opus_int16 x[], /* I Input signal */
1.44 + const opus_int32 minInvGain_Q30 /* I Inverse of max prediction gain */
1.45 +)
1.46 +{
1.47 + opus_int k, subfr_length;
1.48 + opus_int32 a_Q16[ MAX_LPC_ORDER ];
1.49 + opus_int isInterpLower, shift;
1.50 + opus_int32 res_nrg0, res_nrg1;
1.51 + opus_int rshift0, rshift1;
1.52 +
1.53 + /* Used only for LSF interpolation */
1.54 + opus_int32 a_tmp_Q16[ MAX_LPC_ORDER ], res_nrg_interp, res_nrg, res_tmp_nrg;
1.55 + opus_int res_nrg_interp_Q, res_nrg_Q, res_tmp_nrg_Q;
1.56 + opus_int16 a_tmp_Q12[ MAX_LPC_ORDER ];
1.57 + opus_int16 NLSF0_Q15[ MAX_LPC_ORDER ];
1.58 + SAVE_STACK;
1.59 +
1.60 + subfr_length = psEncC->subfr_length + psEncC->predictLPCOrder;
1.61 +
1.62 + /* Default: no interpolation */
1.63 + psEncC->indices.NLSFInterpCoef_Q2 = 4;
1.64 +
1.65 + /* Burg AR analysis for the full frame */
1.66 + silk_burg_modified( &res_nrg, &res_nrg_Q, a_Q16, x, minInvGain_Q30, subfr_length, psEncC->nb_subfr, psEncC->predictLPCOrder, psEncC->arch );
1.67 +
1.68 + if( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) {
1.69 + VARDECL( opus_int16, LPC_res );
1.70 +
1.71 + /* Optimal solution for last 10 ms */
1.72 + 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 );
1.73 +
1.74 + /* subtract residual energy here, as that's easier than adding it to the */
1.75 + /* residual energy of the first 10 ms in each iteration of the search below */
1.76 + shift = res_tmp_nrg_Q - res_nrg_Q;
1.77 + if( shift >= 0 ) {
1.78 + if( shift < 32 ) {
1.79 + res_nrg = res_nrg - silk_RSHIFT( res_tmp_nrg, shift );
1.80 + }
1.81 + } else {
1.82 + silk_assert( shift > -32 );
1.83 + res_nrg = silk_RSHIFT( res_nrg, -shift ) - res_tmp_nrg;
1.84 + res_nrg_Q = res_tmp_nrg_Q;
1.85 + }
1.86 +
1.87 + /* Convert to NLSFs */
1.88 + silk_A2NLSF( NLSF_Q15, a_tmp_Q16, psEncC->predictLPCOrder );
1.89 +
1.90 + ALLOC( LPC_res, 2 * subfr_length, opus_int16 );
1.91 +
1.92 + /* Search over interpolation indices to find the one with lowest residual energy */
1.93 + for( k = 3; k >= 0; k-- ) {
1.94 + /* Interpolate NLSFs for first half */
1.95 + silk_interpolate( NLSF0_Q15, psEncC->prev_NLSFq_Q15, NLSF_Q15, k, psEncC->predictLPCOrder );
1.96 +
1.97 + /* Convert to LPC for residual energy evaluation */
1.98 + silk_NLSF2A( a_tmp_Q12, NLSF0_Q15, psEncC->predictLPCOrder );
1.99 +
1.100 + /* Calculate residual energy with NLSF interpolation */
1.101 + silk_LPC_analysis_filter( LPC_res, x, a_tmp_Q12, 2 * subfr_length, psEncC->predictLPCOrder );
1.102 +
1.103 + silk_sum_sqr_shift( &res_nrg0, &rshift0, LPC_res + psEncC->predictLPCOrder, subfr_length - psEncC->predictLPCOrder );
1.104 + silk_sum_sqr_shift( &res_nrg1, &rshift1, LPC_res + psEncC->predictLPCOrder + subfr_length, subfr_length - psEncC->predictLPCOrder );
1.105 +
1.106 + /* Add subframe energies from first half frame */
1.107 + shift = rshift0 - rshift1;
1.108 + if( shift >= 0 ) {
1.109 + res_nrg1 = silk_RSHIFT( res_nrg1, shift );
1.110 + res_nrg_interp_Q = -rshift0;
1.111 + } else {
1.112 + res_nrg0 = silk_RSHIFT( res_nrg0, -shift );
1.113 + res_nrg_interp_Q = -rshift1;
1.114 + }
1.115 + res_nrg_interp = silk_ADD32( res_nrg0, res_nrg1 );
1.116 +
1.117 + /* Compare with first half energy without NLSF interpolation, or best interpolated value so far */
1.118 + shift = res_nrg_interp_Q - res_nrg_Q;
1.119 + if( shift >= 0 ) {
1.120 + if( silk_RSHIFT( res_nrg_interp, shift ) < res_nrg ) {
1.121 + isInterpLower = silk_TRUE;
1.122 + } else {
1.123 + isInterpLower = silk_FALSE;
1.124 + }
1.125 + } else {
1.126 + if( -shift < 32 ) {
1.127 + if( res_nrg_interp < silk_RSHIFT( res_nrg, -shift ) ) {
1.128 + isInterpLower = silk_TRUE;
1.129 + } else {
1.130 + isInterpLower = silk_FALSE;
1.131 + }
1.132 + } else {
1.133 + isInterpLower = silk_FALSE;
1.134 + }
1.135 + }
1.136 +
1.137 + /* Determine whether current interpolated NLSFs are best so far */
1.138 + if( isInterpLower == silk_TRUE ) {
1.139 + /* Interpolation has lower residual energy */
1.140 + res_nrg = res_nrg_interp;
1.141 + res_nrg_Q = res_nrg_interp_Q;
1.142 + psEncC->indices.NLSFInterpCoef_Q2 = (opus_int8)k;
1.143 + }
1.144 + }
1.145 + }
1.146 +
1.147 + if( psEncC->indices.NLSFInterpCoef_Q2 == 4 ) {
1.148 + /* NLSF interpolation is currently inactive, calculate NLSFs from full frame AR coefficients */
1.149 + silk_A2NLSF( NLSF_Q15, a_Q16, psEncC->predictLPCOrder );
1.150 + }
1.151 +
1.152 + silk_assert( psEncC->indices.NLSFInterpCoef_Q2 == 4 || ( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) );
1.153 + RESTORE_STACK;
1.154 +}
