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 #ifdef HAVE_CONFIG_H

 #include "config.h"

 #endif

 #include "main_FIX.h"

 #include "stack_alloc.h"

 void silk_find_pred_coefs_FIX(

     silk_encoder_state_FIX          *psEnc,                                 /* I/O  encoder state                                                               */

     silk_encoder_control_FIX        *psEncCtrl,                             /* I/O  encoder control                                                             */

     const opus_int16                res_pitch[],                            /* I    Residual from pitch analysis                                                */

     const opus_int16                x[],                                    /* I    Speech signal                                                               */

     opus_int                        condCoding                              /* I    The type of conditional coding to use                                       */

 )

 {

     opus_int         i;

     opus_int32       invGains_Q16[ MAX_NB_SUBFR ], local_gains[ MAX_NB_SUBFR ], Wght_Q15[ MAX_NB_SUBFR ];

     opus_int16       NLSF_Q15[ MAX_LPC_ORDER ];

     const opus_int16 *x_ptr;

     opus_int16       *x_pre_ptr;

     VARDECL( opus_int16, LPC_in_pre );

     opus_int32       tmp, min_gain_Q16, minInvGain_Q30;

     opus_int         LTP_corrs_rshift[ MAX_NB_SUBFR ];

     SAVE_STACK;

     /* weighting for weighted least squares */

     min_gain_Q16 = silk_int32_MAX >> 6;

     for( i = 0; i < psEnc->sCmn.nb_subfr; i++ ) {

         min_gain_Q16 = silk_min( min_gain_Q16, psEncCtrl->Gains_Q16[ i ] );

     }

     for( i = 0; i < psEnc->sCmn.nb_subfr; i++ ) {

         /* Divide to Q16 */

         silk_assert( psEncCtrl->Gains_Q16[ i ] > 0 );

         /* Invert and normalize gains, and ensure that maximum invGains_Q16 is within range of a 16 bit int */

         invGains_Q16[ i ] = silk_DIV32_varQ( min_gain_Q16, psEncCtrl->Gains_Q16[ i ], 16 - 2 );

         /* Ensure Wght_Q15 a minimum value 1 */

         invGains_Q16[ i ] = silk_max( invGains_Q16[ i ], 363 );

         /* Square the inverted gains */

         silk_assert( invGains_Q16[ i ] == silk_SAT16( invGains_Q16[ i ] ) );

         tmp = silk_SMULWB( invGains_Q16[ i ], invGains_Q16[ i ] );

         Wght_Q15[ i ] = silk_RSHIFT( tmp, 1 );

         /* Invert the inverted and normalized gains */

         local_gains[ i ] = silk_DIV32( ( (opus_int32)1 << 16 ), invGains_Q16[ i ] );

     }

     ALLOC( LPC_in_pre,

            psEnc->sCmn.nb_subfr * psEnc->sCmn.predictLPCOrder

                + psEnc->sCmn.frame_length, opus_int16 );

     if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {

         VARDECL( opus_int32, WLTP );

         /**********/

         /* VOICED */

         /**********/

         silk_assert( psEnc->sCmn.ltp_mem_length - psEnc->sCmn.predictLPCOrder >= psEncCtrl->pitchL[ 0 ] + LTP_ORDER / 2 );

         ALLOC( WLTP, psEnc->sCmn.nb_subfr * LTP_ORDER * LTP_ORDER, opus_int32 );

         /* LTP analysis */

         silk_find_LTP_FIX( psEncCtrl->LTPCoef_Q14, WLTP, &psEncCtrl->LTPredCodGain_Q7,

             res_pitch, psEncCtrl->pitchL, Wght_Q15, psEnc->sCmn.subfr_length,

             psEnc->sCmn.nb_subfr, psEnc->sCmn.ltp_mem_length, LTP_corrs_rshift );

         /* Quantize LTP gain parameters */

         silk_quant_LTP_gains( psEncCtrl->LTPCoef_Q14, psEnc->sCmn.indices.LTPIndex, &psEnc->sCmn.indices.PERIndex,

             &psEnc->sCmn.sum_log_gain_Q7, WLTP, psEnc->sCmn.mu_LTP_Q9, psEnc->sCmn.LTPQuantLowComplexity, psEnc->sCmn.nb_subfr);

         /* Control LTP scaling */

         silk_LTP_scale_ctrl_FIX( psEnc, psEncCtrl, condCoding );

         /* Create LTP residual */

         silk_LTP_analysis_filter_FIX( LPC_in_pre, x - psEnc->sCmn.predictLPCOrder, psEncCtrl->LTPCoef_Q14,

             psEncCtrl->pitchL, invGains_Q16, psEnc->sCmn.subfr_length, psEnc->sCmn.nb_subfr, psEnc->sCmn.predictLPCOrder );

     } else {

         /************/

         /* UNVOICED */

         /************/

         /* Create signal with prepended subframes, scaled by inverse gains */

         x_ptr     = x - psEnc->sCmn.predictLPCOrder;

         x_pre_ptr = LPC_in_pre;

         for( i = 0; i < psEnc->sCmn.nb_subfr; i++ ) {

             silk_scale_copy_vector16( x_pre_ptr, x_ptr, invGains_Q16[ i ],

                 psEnc->sCmn.subfr_length + psEnc->sCmn.predictLPCOrder );

             x_pre_ptr += psEnc->sCmn.subfr_length + psEnc->sCmn.predictLPCOrder;

             x_ptr     += psEnc->sCmn.subfr_length;

         }

         silk_memset( psEncCtrl->LTPCoef_Q14, 0, psEnc->sCmn.nb_subfr * LTP_ORDER * sizeof( opus_int16 ) );

         psEncCtrl->LTPredCodGain_Q7 = 0;

 		psEnc->sCmn.sum_log_gain_Q7 = 0;

     }

     /* Limit on total predictive coding gain */

     if( psEnc->sCmn.first_frame_after_reset ) {

         minInvGain_Q30 = SILK_FIX_CONST( 1.0f / MAX_PREDICTION_POWER_GAIN_AFTER_RESET, 30 );

     } else {        

         minInvGain_Q30 = silk_log2lin( silk_SMLAWB( 16 << 7, (opus_int32)psEncCtrl->LTPredCodGain_Q7, SILK_FIX_CONST( 1.0 / 3, 16 ) ) );      /* Q16 */

         minInvGain_Q30 = silk_DIV32_varQ( minInvGain_Q30, 

             silk_SMULWW( SILK_FIX_CONST( MAX_PREDICTION_POWER_GAIN, 0 ), 

                 silk_SMLAWB( SILK_FIX_CONST( 0.25, 18 ), SILK_FIX_CONST( 0.75, 18 ), psEncCtrl->coding_quality_Q14 ) ), 14 );

     }

     /* LPC_in_pre contains the LTP-filtered input for voiced, and the unfiltered input for unvoiced */

     silk_find_LPC_FIX( &psEnc->sCmn, NLSF_Q15, LPC_in_pre, minInvGain_Q30 );

     /* Quantize LSFs */

     silk_process_NLSFs( &psEnc->sCmn, psEncCtrl->PredCoef_Q12, NLSF_Q15, psEnc->sCmn.prev_NLSFq_Q15 );

     /* Calculate residual energy using quantized LPC coefficients */

     silk_residual_energy_FIX( psEncCtrl->ResNrg, psEncCtrl->ResNrgQ, LPC_in_pre, psEncCtrl->PredCoef_Q12, local_gains,

         psEnc->sCmn.subfr_length, psEnc->sCmn.nb_subfr, psEnc->sCmn.predictLPCOrder );

     /* Copy to prediction struct for use in next frame for interpolation */

     silk_memcpy( psEnc->sCmn.prev_NLSFq_Q15, NLSF_Q15, sizeof( psEnc->sCmn.prev_NLSFq_Q15 ) );

     RESTORE_STACK;

 }