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 #ifdef HAVE_CONFIG_H

 #include "config.h"

 #endif

 #include "main_FIX.h"

 #include "stack_alloc.h"

 #include "tuning_parameters.h"

 /* Find pitch lags */

 void silk_find_pitch_lags_FIX(

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

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

     opus_int16                      res[],                                  /* O    residual                                                                    */

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

     int                             arch                                    /* I    Run-time architecture                                                       */

 )

 {

     opus_int   buf_len, i, scale;

     opus_int32 thrhld_Q13, res_nrg;

     const opus_int16 *x_buf, *x_buf_ptr;

     VARDECL( opus_int16, Wsig );

     opus_int16 *Wsig_ptr;

     opus_int32 auto_corr[ MAX_FIND_PITCH_LPC_ORDER + 1 ];

     opus_int16 rc_Q15[    MAX_FIND_PITCH_LPC_ORDER ];

     opus_int32 A_Q24[     MAX_FIND_PITCH_LPC_ORDER ];

     opus_int16 A_Q12[     MAX_FIND_PITCH_LPC_ORDER ];

     SAVE_STACK;

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

     /* Set up buffer lengths etc based on Fs  */

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

     buf_len = psEnc->sCmn.la_pitch + psEnc->sCmn.frame_length + psEnc->sCmn.ltp_mem_length;

     /* Safety check */

     silk_assert( buf_len >= psEnc->sCmn.pitch_LPC_win_length );

     x_buf = x - psEnc->sCmn.ltp_mem_length;

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

     /* Estimate LPC AR coefficients      */

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

     /* Calculate windowed signal */

     ALLOC( Wsig, psEnc->sCmn.pitch_LPC_win_length, opus_int16 );

     /* First LA_LTP samples */

     x_buf_ptr = x_buf + buf_len - psEnc->sCmn.pitch_LPC_win_length;

     Wsig_ptr  = Wsig;

     silk_apply_sine_window( Wsig_ptr, x_buf_ptr, 1, psEnc->sCmn.la_pitch );

     /* Middle un - windowed samples */

     Wsig_ptr  += psEnc->sCmn.la_pitch;

     x_buf_ptr += psEnc->sCmn.la_pitch;

     silk_memcpy( Wsig_ptr, x_buf_ptr, ( psEnc->sCmn.pitch_LPC_win_length - silk_LSHIFT( psEnc->sCmn.la_pitch, 1 ) ) * sizeof( opus_int16 ) );

     /* Last LA_LTP samples */

     Wsig_ptr  += psEnc->sCmn.pitch_LPC_win_length - silk_LSHIFT( psEnc->sCmn.la_pitch, 1 );

     x_buf_ptr += psEnc->sCmn.pitch_LPC_win_length - silk_LSHIFT( psEnc->sCmn.la_pitch, 1 );

     silk_apply_sine_window( Wsig_ptr, x_buf_ptr, 2, psEnc->sCmn.la_pitch );

     /* Calculate autocorrelation sequence */

     silk_autocorr( auto_corr, &scale, Wsig, psEnc->sCmn.pitch_LPC_win_length, psEnc->sCmn.pitchEstimationLPCOrder + 1, arch );

     /* Add white noise, as fraction of energy */

     auto_corr[ 0 ] = silk_SMLAWB( auto_corr[ 0 ], auto_corr[ 0 ], SILK_FIX_CONST( FIND_PITCH_WHITE_NOISE_FRACTION, 16 ) ) + 1;

     /* Calculate the reflection coefficients using schur */

     res_nrg = silk_schur( rc_Q15, auto_corr, psEnc->sCmn.pitchEstimationLPCOrder );

     /* Prediction gain */

     psEncCtrl->predGain_Q16 = silk_DIV32_varQ( auto_corr[ 0 ], silk_max_int( res_nrg, 1 ), 16 );

     /* Convert reflection coefficients to prediction coefficients */

     silk_k2a( A_Q24, rc_Q15, psEnc->sCmn.pitchEstimationLPCOrder );

     /* Convert From 32 bit Q24 to 16 bit Q12 coefs */

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

         A_Q12[ i ] = (opus_int16)silk_SAT16( silk_RSHIFT( A_Q24[ i ], 12 ) );

     }

     /* Do BWE */

     silk_bwexpander( A_Q12, psEnc->sCmn.pitchEstimationLPCOrder, SILK_FIX_CONST( FIND_PITCH_BANDWIDTH_EXPANSION, 16 ) );

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

     /* LPC analysis filtering                */

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

     silk_LPC_analysis_filter( res, x_buf, A_Q12, buf_len, psEnc->sCmn.pitchEstimationLPCOrder );

     if( psEnc->sCmn.indices.signalType != TYPE_NO_VOICE_ACTIVITY && psEnc->sCmn.first_frame_after_reset == 0 ) {

         /* Threshold for pitch estimator */

         thrhld_Q13 = SILK_FIX_CONST( 0.6, 13 );

         thrhld_Q13 = silk_SMLABB( thrhld_Q13, SILK_FIX_CONST( -0.004, 13 ), psEnc->sCmn.pitchEstimationLPCOrder );

         thrhld_Q13 = silk_SMLAWB( thrhld_Q13, SILK_FIX_CONST( -0.1,   21  ), psEnc->sCmn.speech_activity_Q8 );

         thrhld_Q13 = silk_SMLABB( thrhld_Q13, SILK_FIX_CONST( -0.15,  13 ), silk_RSHIFT( psEnc->sCmn.prevSignalType, 1 ) );

         thrhld_Q13 = silk_SMLAWB( thrhld_Q13, SILK_FIX_CONST( -0.1,   14 ), psEnc->sCmn.input_tilt_Q15 );

         thrhld_Q13 = silk_SAT16(  thrhld_Q13 );

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

         /* Call pitch estimator                  */

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

         if( silk_pitch_analysis_core( res, psEncCtrl->pitchL, &psEnc->sCmn.indices.lagIndex, &psEnc->sCmn.indices.contourIndex,

                 &psEnc->LTPCorr_Q15, psEnc->sCmn.prevLag, psEnc->sCmn.pitchEstimationThreshold_Q16,

                 (opus_int)thrhld_Q13, psEnc->sCmn.fs_kHz, psEnc->sCmn.pitchEstimationComplexity, psEnc->sCmn.nb_subfr,

                 psEnc->sCmn.arch) == 0 )

         {

             psEnc->sCmn.indices.signalType = TYPE_VOICED;

         } else {

             psEnc->sCmn.indices.signalType = TYPE_UNVOICED;

         }

     } else {

         silk_memset( psEncCtrl->pitchL, 0, sizeof( psEncCtrl->pitchL ) );

         psEnc->sCmn.indices.lagIndex = 0;

         psEnc->sCmn.indices.contourIndex = 0;

         psEnc->LTPCorr_Q15 = 0;

     }

     RESTORE_STACK;

 }