silk-sys 0.1.0

/***********************************************************************
Copyright (c) 2006-2012, Skype Limited. All rights reserved. 
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modification, (subject to the limitations in the disclaimer below) 
are permitted provided that the following conditions are met:
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BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
***********************************************************************/

#include "SKP_Silk_main_FIX.h"
#include "SKP_Silk_tuning_parameters.h"

/* Compute gain to make warped filter coefficients have a zero mean log frequency response on a     */
/* non-warped frequency scale. (So that it can be implemented with a minimum-phase monic filter.)   */
SKP_INLINE SKP_int32 warped_gain( // gain in Q16
    const SKP_int32     *coefs_Q24, 
    SKP_int             lambda_Q16, 
    SKP_int             order 
) {
    SKP_int   i;
    SKP_int32 gain_Q24;

    lambda_Q16 = -lambda_Q16;
    gain_Q24 = coefs_Q24[ order - 1 ];
    for( i = order - 2; i >= 0; i-- ) {
        gain_Q24 = SKP_SMLAWB( coefs_Q24[ i ], gain_Q24, lambda_Q16 );
    }
    gain_Q24  = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 24 ), gain_Q24, -lambda_Q16 );
    return SKP_INVERSE32_varQ( gain_Q24, 40 );
}

/* Convert warped filter coefficients to monic pseudo-warped coefficients and limit maximum     */
/* amplitude of monic warped coefficients by using bandwidth expansion on the true coefficients */
SKP_INLINE void limit_warped_coefs( 
    SKP_int32           *coefs_syn_Q24,
    SKP_int32           *coefs_ana_Q24,
    SKP_int             lambda_Q16,
    SKP_int32           limit_Q24,
    SKP_int             order
) {
    SKP_int   i, iter, ind = 0;
    SKP_int32 tmp, maxabs_Q24, chirp_Q16, gain_syn_Q16, gain_ana_Q16;
    SKP_int32 nom_Q16, den_Q24;

    /* Convert to monic coefficients */
    lambda_Q16 = -lambda_Q16;
    for( i = order - 1; i > 0; i-- ) {
        coefs_syn_Q24[ i - 1 ] = SKP_SMLAWB( coefs_syn_Q24[ i - 1 ], coefs_syn_Q24[ i ], lambda_Q16 );
        coefs_ana_Q24[ i - 1 ] = SKP_SMLAWB( coefs_ana_Q24[ i - 1 ], coefs_ana_Q24[ i ], lambda_Q16 );
    }
    lambda_Q16 = -lambda_Q16;
    nom_Q16  = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 16 ), -lambda_Q16,        lambda_Q16 );
    den_Q24  = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 24 ), coefs_syn_Q24[ 0 ], lambda_Q16 );
    gain_syn_Q16 = SKP_DIV32_varQ( nom_Q16, den_Q24, 24 );
    den_Q24  = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 24 ), coefs_ana_Q24[ 0 ], lambda_Q16 );
    gain_ana_Q16 = SKP_DIV32_varQ( nom_Q16, den_Q24, 24 );
    for( i = 0; i < order; i++ ) {
        coefs_syn_Q24[ i ] = SKP_SMULWW( gain_syn_Q16, coefs_syn_Q24[ i ] );
        coefs_ana_Q24[ i ] = SKP_SMULWW( gain_ana_Q16, coefs_ana_Q24[ i ] );
    }

    for( iter = 0; iter < 10; iter++ ) {
        /* Find maximum absolute value */
        maxabs_Q24 = -1;
        for( i = 0; i < order; i++ ) {
            tmp = SKP_max( SKP_abs_int32( coefs_syn_Q24[ i ] ), SKP_abs_int32( coefs_ana_Q24[ i ] ) );
            if( tmp > maxabs_Q24 ) {
                maxabs_Q24 = tmp;
                ind = i;
            }
        }
        if( maxabs_Q24 <= limit_Q24 ) {
            /* Coefficients are within range - done */
            return;
        }

        /* Convert back to true warped coefficients */
        for( i = 1; i < order; i++ ) {
            coefs_syn_Q24[ i - 1 ] = SKP_SMLAWB( coefs_syn_Q24[ i - 1 ], coefs_syn_Q24[ i ], lambda_Q16 );
            coefs_ana_Q24[ i - 1 ] = SKP_SMLAWB( coefs_ana_Q24[ i - 1 ], coefs_ana_Q24[ i ], lambda_Q16 );
        }
        gain_syn_Q16 = SKP_INVERSE32_varQ( gain_syn_Q16, 32 );
        gain_ana_Q16 = SKP_INVERSE32_varQ( gain_ana_Q16, 32 );
        for( i = 0; i < order; i++ ) {
            coefs_syn_Q24[ i ] = SKP_SMULWW( gain_syn_Q16, coefs_syn_Q24[ i ] );
            coefs_ana_Q24[ i ] = SKP_SMULWW( gain_ana_Q16, coefs_ana_Q24[ i ] );
        }

        /* Apply bandwidth expansion */
        chirp_Q16 = SKP_FIX_CONST( 0.99, 16 ) - SKP_DIV32_varQ(
            SKP_SMULWB( maxabs_Q24 - limit_Q24, SKP_SMLABB( SKP_FIX_CONST( 0.8, 10 ), SKP_FIX_CONST( 0.1, 10 ), iter ) ), 
            SKP_MUL( maxabs_Q24, ind + 1 ), 22 );
        SKP_Silk_bwexpander_32( coefs_syn_Q24, order, chirp_Q16 );
        SKP_Silk_bwexpander_32( coefs_ana_Q24, order, chirp_Q16 );

        /* Convert to monic warped coefficients */
        lambda_Q16 = -lambda_Q16;
        for( i = order - 1; i > 0; i-- ) {
            coefs_syn_Q24[ i - 1 ] = SKP_SMLAWB( coefs_syn_Q24[ i - 1 ], coefs_syn_Q24[ i ], lambda_Q16 );
            coefs_ana_Q24[ i - 1 ] = SKP_SMLAWB( coefs_ana_Q24[ i - 1 ], coefs_ana_Q24[ i ], lambda_Q16 );
        }
        lambda_Q16 = -lambda_Q16;
        nom_Q16  = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 16 ), -lambda_Q16,        lambda_Q16 );
        den_Q24  = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 24 ), coefs_syn_Q24[ 0 ], lambda_Q16 );
        gain_syn_Q16 = SKP_DIV32_varQ( nom_Q16, den_Q24, 24 );
        den_Q24  = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 24 ), coefs_ana_Q24[ 0 ], lambda_Q16 );
        gain_ana_Q16 = SKP_DIV32_varQ( nom_Q16, den_Q24, 24 );
        for( i = 0; i < order; i++ ) {
            coefs_syn_Q24[ i ] = SKP_SMULWW( gain_syn_Q16, coefs_syn_Q24[ i ] );
            coefs_ana_Q24[ i ] = SKP_SMULWW( gain_ana_Q16, coefs_ana_Q24[ i ] );
        }
    }
	SKP_assert( 0 );
}

/**************************************************************/
/* Compute noise shaping coefficients and initial gain values */
/**************************************************************/
void SKP_Silk_noise_shape_analysis_FIX(
    SKP_Silk_encoder_state_FIX      *psEnc,         /* I/O  Encoder state FIX                           */
    SKP_Silk_encoder_control_FIX    *psEncCtrl,     /* I/O  Encoder control FIX                         */
    const SKP_int16                 *pitch_res,     /* I    LPC residual from pitch analysis            */
    const SKP_int16                 *x              /* I    Input signal [ frame_length + la_shape ]    */
)
{
    SKP_Silk_shape_state_FIX *psShapeSt = &psEnc->sShape;
    SKP_int     k, i, nSamples, Qnrg, b_Q14, warping_Q16, scale = 0;
    SKP_int32   SNR_adj_dB_Q7, HarmBoost_Q16, HarmShapeGain_Q16, Tilt_Q16, tmp32;
    SKP_int32   nrg, pre_nrg_Q30, log_energy_Q7, log_energy_prev_Q7, energy_variation_Q7;
    SKP_int32   delta_Q16, BWExp1_Q16, BWExp2_Q16, gain_mult_Q16, gain_add_Q16, strength_Q16, b_Q8;
    SKP_int32   auto_corr[     MAX_SHAPE_LPC_ORDER + 1 ];
    SKP_int32   refl_coef_Q16[ MAX_SHAPE_LPC_ORDER ];
    SKP_int32   AR1_Q24[       MAX_SHAPE_LPC_ORDER ];
    SKP_int32   AR2_Q24[       MAX_SHAPE_LPC_ORDER ];
    SKP_int16   x_windowed[    SHAPE_LPC_WIN_MAX ];
    const SKP_int16 *x_ptr, *pitch_res_ptr;

    /* Point to start of first LPC analysis block */
    x_ptr = x - psEnc->sCmn.la_shape;

    /****************/
    /* CONTROL SNR  */
    /****************/
    /* Reduce SNR_dB values if recent bitstream has exceeded TargetRate */
    psEncCtrl->current_SNR_dB_Q7 = psEnc->SNR_dB_Q7 - SKP_SMULWB( SKP_LSHIFT( ( SKP_int32 )psEnc->BufferedInChannel_ms, 7 ), 
        SKP_FIX_CONST( 0.05, 16 ) );

    /* Reduce SNR_dB if inband FEC used */
    if( psEnc->speech_activity_Q8 > SKP_FIX_CONST( LBRR_SPEECH_ACTIVITY_THRES, 8 ) ) {
        psEncCtrl->current_SNR_dB_Q7 -= SKP_RSHIFT( psEnc->inBandFEC_SNR_comp_Q8, 1 );
    }

    /****************/
    /* GAIN CONTROL */
    /****************/
    /* Input quality is the average of the quality in the lowest two VAD bands */
    psEncCtrl->input_quality_Q14 = ( SKP_int )SKP_RSHIFT( ( SKP_int32 )psEncCtrl->input_quality_bands_Q15[ 0 ] 
        + psEncCtrl->input_quality_bands_Q15[ 1 ], 2 );

    /* Coding quality level, between 0.0_Q0 and 1.0_Q0, but in Q14 */
    psEncCtrl->coding_quality_Q14 = SKP_RSHIFT( SKP_Silk_sigm_Q15( SKP_RSHIFT_ROUND( psEncCtrl->current_SNR_dB_Q7 - 
        SKP_FIX_CONST( 18.0, 7 ), 4 ) ), 1 );

    /* Reduce coding SNR during low speech activity */
    b_Q8 = SKP_FIX_CONST( 1.0, 8 ) - psEnc->speech_activity_Q8;
    b_Q8 = SKP_SMULWB( SKP_LSHIFT( b_Q8, 8 ), b_Q8 );
    SNR_adj_dB_Q7 = SKP_SMLAWB( psEncCtrl->current_SNR_dB_Q7,
        SKP_SMULBB( SKP_FIX_CONST( -BG_SNR_DECR_dB, 7 ) >> ( 4 + 1 ), b_Q8 ),                                       // Q11
        SKP_SMULWB( SKP_FIX_CONST( 1.0, 14 ) + psEncCtrl->input_quality_Q14, psEncCtrl->coding_quality_Q14 ) );     // Q12

    if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) {
        /* Reduce gains for periodic signals */
        SNR_adj_dB_Q7 = SKP_SMLAWB( SNR_adj_dB_Q7, SKP_FIX_CONST( HARM_SNR_INCR_dB, 8 ), psEnc->LTPCorr_Q15 );
    } else { 
        /* For unvoiced signals and low-quality input, adjust the quality slower than SNR_dB setting */
        SNR_adj_dB_Q7 = SKP_SMLAWB( SNR_adj_dB_Q7, 
            SKP_SMLAWB( SKP_FIX_CONST( 6.0, 9 ), -SKP_FIX_CONST( 0.4, 18 ), psEncCtrl->current_SNR_dB_Q7 ),
            SKP_FIX_CONST( 1.0, 14 ) - psEncCtrl->input_quality_Q14 );
    }

    /*************************/
    /* SPARSENESS PROCESSING */
    /*************************/
    /* Set quantizer offset */
    if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) {
        /* Initally set to 0; may be overruled in process_gains(..) */
        psEncCtrl->sCmn.QuantOffsetType = 0;
        psEncCtrl->sparseness_Q8 = 0;
    } else {
        /* Sparseness measure, based on relative fluctuations of energy per 2 milliseconds */
        nSamples = SKP_LSHIFT( psEnc->sCmn.fs_kHz, 1 );
        energy_variation_Q7 = 0;
        log_energy_prev_Q7  = 0;
        pitch_res_ptr = pitch_res;
        for( k = 0; k < FRAME_LENGTH_MS / 2; k++ ) {    
            SKP_Silk_sum_sqr_shift( &nrg, &scale, pitch_res_ptr, nSamples );
            nrg += SKP_RSHIFT( nSamples, scale );           // Q(-scale)
            
            log_energy_Q7 = SKP_Silk_lin2log( nrg );
            if( k > 0 ) {
                energy_variation_Q7 += SKP_abs( log_energy_Q7 - log_energy_prev_Q7 );
            }
            log_energy_prev_Q7 = log_energy_Q7;
            pitch_res_ptr += nSamples;
        }

        psEncCtrl->sparseness_Q8 = SKP_RSHIFT( SKP_Silk_sigm_Q15( SKP_SMULWB( energy_variation_Q7 - 
            SKP_FIX_CONST( 5.0, 7 ), SKP_FIX_CONST( 0.1, 16 ) ) ), 7 );

        /* Set quantization offset depending on sparseness measure */
        if( psEncCtrl->sparseness_Q8 > SKP_FIX_CONST( SPARSENESS_THRESHOLD_QNT_OFFSET, 8 ) ) {
            psEncCtrl->sCmn.QuantOffsetType = 0;
        } else {
            psEncCtrl->sCmn.QuantOffsetType = 1;
        }
        
        /* Increase coding SNR for sparse signals */
        SNR_adj_dB_Q7 = SKP_SMLAWB( SNR_adj_dB_Q7, SKP_FIX_CONST( SPARSE_SNR_INCR_dB, 15 ), psEncCtrl->sparseness_Q8 - SKP_FIX_CONST( 0.5, 8 ) );
    }

    /*******************************/
    /* Control bandwidth expansion */
    /*******************************/
    /* More BWE for signals with high prediction gain */
    strength_Q16 = SKP_SMULWB( psEncCtrl->predGain_Q16, SKP_FIX_CONST( FIND_PITCH_WHITE_NOISE_FRACTION, 16 ) );
    BWExp1_Q16 = BWExp2_Q16 = SKP_DIV32_varQ( SKP_FIX_CONST( BANDWIDTH_EXPANSION, 16 ), 
        SKP_SMLAWW( SKP_FIX_CONST( 1.0, 16 ), strength_Q16, strength_Q16 ), 16 );
    delta_Q16  = SKP_SMULWB( SKP_FIX_CONST( 1.0, 16 ) - SKP_SMULBB( 3, psEncCtrl->coding_quality_Q14 ), 
        SKP_FIX_CONST( LOW_RATE_BANDWIDTH_EXPANSION_DELTA, 16 ) );
    BWExp1_Q16 = SKP_SUB32( BWExp1_Q16, delta_Q16 );
    BWExp2_Q16 = SKP_ADD32( BWExp2_Q16, delta_Q16 );
    /* BWExp1 will be applied after BWExp2, so make it relative */
    BWExp1_Q16 = SKP_DIV32_16( SKP_LSHIFT( BWExp1_Q16, 14 ), SKP_RSHIFT( BWExp2_Q16, 2 ) );

    if( psEnc->sCmn.warping_Q16 > 0 ) {
        /* Slightly more warping in analysis will move quantization noise up in frequency, where it's better masked */
        warping_Q16 = SKP_SMLAWB( psEnc->sCmn.warping_Q16, psEncCtrl->coding_quality_Q14, SKP_FIX_CONST( 0.01, 18 ) );
    } else {
        warping_Q16 = 0;
    }

    /********************************************/
    /* Compute noise shaping AR coefs and gains */
    /********************************************/
    for( k = 0; k < NB_SUBFR; k++ ) {
        /* Apply window: sine slope followed by flat part followed by cosine slope */
        SKP_int shift, slope_part, flat_part;
        flat_part = psEnc->sCmn.fs_kHz * 5;
        slope_part = SKP_RSHIFT( psEnc->sCmn.shapeWinLength - flat_part, 1 );

        SKP_Silk_apply_sine_window( x_windowed, x_ptr, 1, slope_part );
        shift = slope_part;
        SKP_memcpy( x_windowed + shift, x_ptr + shift, flat_part * sizeof(SKP_int16) );
        shift += flat_part;
        SKP_Silk_apply_sine_window( x_windowed + shift, x_ptr + shift, 2, slope_part );
        
        /* Update pointer: next LPC analysis block */
        x_ptr += psEnc->sCmn.subfr_length;

        if( psEnc->sCmn.warping_Q16 > 0 ) {
            /* Calculate warped auto correlation */
            SKP_Silk_warped_autocorrelation_FIX( auto_corr, &scale, x_windowed, warping_Q16, psEnc->sCmn.shapeWinLength, psEnc->sCmn.shapingLPCOrder ); 
        } else {
            /* Calculate regular auto correlation */
            SKP_Silk_autocorr( auto_corr, &scale, x_windowed, psEnc->sCmn.shapeWinLength, psEnc->sCmn.shapingLPCOrder + 1 );
        }

        /* Add white noise, as a fraction of energy */
        auto_corr[0] = SKP_ADD32( auto_corr[0], SKP_max_32( SKP_SMULWB( SKP_RSHIFT( auto_corr[ 0 ], 4 ), 
            SKP_FIX_CONST( SHAPE_WHITE_NOISE_FRACTION, 20 ) ), 1 ) ); 

        /* Calculate the reflection coefficients using schur */
        nrg = SKP_Silk_schur64( refl_coef_Q16, auto_corr, psEnc->sCmn.shapingLPCOrder );
        SKP_assert( nrg >= 0 );

        /* Convert reflection coefficients to prediction coefficients */
        SKP_Silk_k2a_Q16( AR2_Q24, refl_coef_Q16, psEnc->sCmn.shapingLPCOrder );

        Qnrg = -scale;          // range: -12...30
        SKP_assert( Qnrg >= -12 );
        SKP_assert( Qnrg <=  30 );

        /* Make sure that Qnrg is an even number */
        if( Qnrg & 1 ) {
            Qnrg -= 1;
            nrg >>= 1;
        }

        tmp32 = SKP_Silk_SQRT_APPROX( nrg );
        Qnrg >>= 1;             // range: -6...15

        psEncCtrl->Gains_Q16[ k ] = SKP_LSHIFT_SAT32( tmp32, 16 - Qnrg );

        if( psEnc->sCmn.warping_Q16 > 0 ) {
            /* Adjust gain for warping */
            gain_mult_Q16 = warped_gain( AR2_Q24, warping_Q16, psEnc->sCmn.shapingLPCOrder );
            SKP_assert( psEncCtrl->Gains_Q16[ k ] >= 0 );
            psEncCtrl->Gains_Q16[ k ] = SKP_SMULWW( psEncCtrl->Gains_Q16[ k ], gain_mult_Q16 );
            if( psEncCtrl->Gains_Q16[ k ] < 0 ) {
                psEncCtrl->Gains_Q16[ k ] = SKP_int32_MAX;
            }
        }

        /* Bandwidth expansion for synthesis filter shaping */
        SKP_Silk_bwexpander_32( AR2_Q24, psEnc->sCmn.shapingLPCOrder, BWExp2_Q16 );

        /* Compute noise shaping filter coefficients */
        SKP_memcpy( AR1_Q24, AR2_Q24, psEnc->sCmn.shapingLPCOrder * sizeof( SKP_int32 ) );

        /* Bandwidth expansion for analysis filter shaping */
        SKP_assert( BWExp1_Q16 <= SKP_FIX_CONST( 1.0, 16 ) );
        SKP_Silk_bwexpander_32( AR1_Q24, psEnc->sCmn.shapingLPCOrder, BWExp1_Q16 );

        /* Ratio of prediction gains, in energy domain */
        SKP_Silk_LPC_inverse_pred_gain_Q24( &pre_nrg_Q30, AR2_Q24, psEnc->sCmn.shapingLPCOrder );
        SKP_Silk_LPC_inverse_pred_gain_Q24( &nrg,         AR1_Q24, psEnc->sCmn.shapingLPCOrder );

        //psEncCtrl->GainsPre[ k ] = 1.0f - 0.7f * ( 1.0f - pre_nrg / nrg ) = 0.3f + 0.7f * pre_nrg / nrg;
        pre_nrg_Q30 = SKP_LSHIFT32( SKP_SMULWB( pre_nrg_Q30, SKP_FIX_CONST( 0.7, 15 ) ), 1 );
        psEncCtrl->GainsPre_Q14[ k ] = ( SKP_int ) SKP_FIX_CONST( 0.3, 14 ) + SKP_DIV32_varQ( pre_nrg_Q30, nrg, 14 );

        /* Convert to monic warped prediction coefficients and limit absolute values */
        limit_warped_coefs( AR2_Q24, AR1_Q24, warping_Q16, SKP_FIX_CONST( 3.999, 24 ), psEnc->sCmn.shapingLPCOrder );

        /* Convert from Q24 to Q13 and store in int16 */
        for( i = 0; i < psEnc->sCmn.shapingLPCOrder; i++ ) {
            psEncCtrl->AR1_Q13[ k * MAX_SHAPE_LPC_ORDER + i ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( AR1_Q24[ i ], 11 ) );
            psEncCtrl->AR2_Q13[ k * MAX_SHAPE_LPC_ORDER + i ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( AR2_Q24[ i ], 11 ) );
        }
    }

    /*****************/
    /* Gain tweaking */
    /*****************/
    /* Increase gains during low speech activity and put lower limit on gains */
    gain_mult_Q16 = SKP_Silk_log2lin( -SKP_SMLAWB( -SKP_FIX_CONST( 16.0, 7 ), SNR_adj_dB_Q7,                            SKP_FIX_CONST( 0.16, 16 ) ) );
    gain_add_Q16  = SKP_Silk_log2lin(  SKP_SMLAWB(  SKP_FIX_CONST( 16.0, 7 ), SKP_FIX_CONST( NOISE_FLOOR_dB, 7 ),       SKP_FIX_CONST( 0.16, 16 ) ) );
    tmp32         = SKP_Silk_log2lin(  SKP_SMLAWB(  SKP_FIX_CONST( 16.0, 7 ), SKP_FIX_CONST( RELATIVE_MIN_GAIN_dB, 7 ), SKP_FIX_CONST( 0.16, 16 ) ) );
    tmp32 = SKP_SMULWW( psEnc->avgGain_Q16, tmp32 );
    gain_add_Q16 = SKP_ADD_SAT32( gain_add_Q16, tmp32 );
    SKP_assert( gain_mult_Q16 >= 0 );

    for( k = 0; k < NB_SUBFR; k++ ) {
        psEncCtrl->Gains_Q16[ k ] = SKP_SMULWW( psEncCtrl->Gains_Q16[ k ], gain_mult_Q16 );
        if( psEncCtrl->Gains_Q16[ k ] < 0 ) {
            psEncCtrl->Gains_Q16[ k ] = SKP_int32_MAX;
        }
    }

    for( k = 0; k < NB_SUBFR; k++ ) {
        psEncCtrl->Gains_Q16[ k ] = SKP_ADD_POS_SAT32( psEncCtrl->Gains_Q16[ k ], gain_add_Q16 );
        psEnc->avgGain_Q16 = SKP_ADD_SAT32( 
            psEnc->avgGain_Q16, 
            SKP_SMULWB(
                psEncCtrl->Gains_Q16[ k ] - psEnc->avgGain_Q16, 
                SKP_RSHIFT_ROUND( SKP_SMULBB( psEnc->speech_activity_Q8, SKP_FIX_CONST( GAIN_SMOOTHING_COEF, 10 ) ), 2 ) 
            ) );
    }

    /************************************************/
    /* Decrease level during fricatives (de-essing) */
    /************************************************/
    gain_mult_Q16 = SKP_FIX_CONST( 1.0, 16 ) + SKP_RSHIFT_ROUND( SKP_MLA( SKP_FIX_CONST( INPUT_TILT, 26 ), 
        psEncCtrl->coding_quality_Q14, SKP_FIX_CONST( HIGH_RATE_INPUT_TILT, 12 ) ), 10 );

    if( psEncCtrl->input_tilt_Q15 <= 0 && psEncCtrl->sCmn.sigtype == SIG_TYPE_UNVOICED ) {
        if( psEnc->sCmn.fs_kHz == 24 ) {
            SKP_int32 essStrength_Q15 = SKP_SMULWW( -psEncCtrl->input_tilt_Q15, 
                SKP_SMULBB( psEnc->speech_activity_Q8, SKP_FIX_CONST( 1.0, 8 ) - psEncCtrl->sparseness_Q8 ) );
            tmp32 = SKP_Silk_log2lin( SKP_FIX_CONST( 16.0, 7 ) - SKP_SMULWB( essStrength_Q15, 
                SKP_SMULWB( SKP_FIX_CONST( DE_ESSER_COEF_SWB_dB, 7 ), SKP_FIX_CONST( 0.16, 17 ) ) ) );
            gain_mult_Q16 = SKP_SMULWW( gain_mult_Q16, tmp32 );
        } else if( psEnc->sCmn.fs_kHz == 16 ) {
            SKP_int32 essStrength_Q15 = SKP_SMULWW(-psEncCtrl->input_tilt_Q15, 
                SKP_SMULBB( psEnc->speech_activity_Q8, SKP_FIX_CONST( 1.0, 8 ) - psEncCtrl->sparseness_Q8 ));
            tmp32 = SKP_Silk_log2lin( SKP_FIX_CONST( 16.0, 7 ) - SKP_SMULWB( essStrength_Q15, 
                SKP_SMULWB( SKP_FIX_CONST( DE_ESSER_COEF_WB_dB, 7 ), SKP_FIX_CONST( 0.16, 17 ) ) ) );
            gain_mult_Q16 = SKP_SMULWW( gain_mult_Q16, tmp32 );
        } else {
            SKP_assert( psEnc->sCmn.fs_kHz == 12 || psEnc->sCmn.fs_kHz == 8 );
        }
    }

    for( k = 0; k < NB_SUBFR; k++ ) {
        psEncCtrl->GainsPre_Q14[ k ] = SKP_SMULWB( gain_mult_Q16, psEncCtrl->GainsPre_Q14[ k ] );
    }

    /************************************************/
    /* Control low-frequency shaping and noise tilt */
    /************************************************/
    /* Less low frequency shaping for noisy inputs */
    strength_Q16 = SKP_MUL( SKP_FIX_CONST( LOW_FREQ_SHAPING, 0 ), SKP_FIX_CONST( 1.0, 16 ) + 
        SKP_SMULBB( SKP_FIX_CONST( LOW_QUALITY_LOW_FREQ_SHAPING_DECR, 1 ), psEncCtrl->input_quality_bands_Q15[ 0 ] - SKP_FIX_CONST( 1.0, 15 ) ) );
    if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) {
        /* Reduce low frequencies quantization noise for periodic signals, depending on pitch lag */
        /*f = 400; freqz([1, -0.98 + 2e-4 * f], [1, -0.97 + 7e-4 * f], 2^12, Fs); axis([0, 1000, -10, 1])*/
        SKP_int fs_kHz_inv = SKP_DIV32_16( SKP_FIX_CONST( 0.2, 14 ), psEnc->sCmn.fs_kHz );
        for( k = 0; k < NB_SUBFR; k++ ) {
            b_Q14 = fs_kHz_inv + SKP_DIV32_16( SKP_FIX_CONST( 3.0, 14 ), psEncCtrl->sCmn.pitchL[ k ] ); 
            /* Pack two coefficients in one int32 */
            psEncCtrl->LF_shp_Q14[ k ]  = SKP_LSHIFT( SKP_FIX_CONST( 1.0, 14 ) - b_Q14 - SKP_SMULWB( strength_Q16, b_Q14 ), 16 );
            psEncCtrl->LF_shp_Q14[ k ] |= (SKP_uint16)( b_Q14 - SKP_FIX_CONST( 1.0, 14 ) );
        }
        SKP_assert( SKP_FIX_CONST( HARM_HP_NOISE_COEF, 24 ) < SKP_FIX_CONST( 0.5, 24 ) ); // Guarantees that second argument to SMULWB() is within range of an SKP_int16
        Tilt_Q16 = - SKP_FIX_CONST( HP_NOISE_COEF, 16 ) - 
            SKP_SMULWB( SKP_FIX_CONST( 1.0, 16 ) - SKP_FIX_CONST( HP_NOISE_COEF, 16 ), 
                SKP_SMULWB( SKP_FIX_CONST( HARM_HP_NOISE_COEF, 24 ), psEnc->speech_activity_Q8 ) );
    } else {
        b_Q14 = SKP_DIV32_16( 21299, psEnc->sCmn.fs_kHz ); // 1.3_Q0 = 21299_Q14
        /* Pack two coefficients in one int32 */
        psEncCtrl->LF_shp_Q14[ 0 ]  = SKP_LSHIFT( SKP_FIX_CONST( 1.0, 14 ) - b_Q14 - 
            SKP_SMULWB( strength_Q16, SKP_SMULWB( SKP_FIX_CONST( 0.6, 16 ), b_Q14 ) ), 16 );
        psEncCtrl->LF_shp_Q14[ 0 ] |= (SKP_uint16)( b_Q14 - SKP_FIX_CONST( 1.0, 14 ) );
        for( k = 1; k < NB_SUBFR; k++ ) {
            psEncCtrl->LF_shp_Q14[ k ] = psEncCtrl->LF_shp_Q14[ 0 ];
        }
        Tilt_Q16 = -SKP_FIX_CONST( HP_NOISE_COEF, 16 );
    }

    /****************************/
    /* HARMONIC SHAPING CONTROL */
    /****************************/
    /* Control boosting of harmonic frequencies */
    HarmBoost_Q16 = SKP_SMULWB( SKP_SMULWB( SKP_FIX_CONST( 1.0, 17 ) - SKP_LSHIFT( psEncCtrl->coding_quality_Q14, 3 ), 
        psEnc->LTPCorr_Q15 ), SKP_FIX_CONST( LOW_RATE_HARMONIC_BOOST, 16 ) );

    /* More harmonic boost for noisy input signals */
    HarmBoost_Q16 = SKP_SMLAWB( HarmBoost_Q16, 
        SKP_FIX_CONST( 1.0, 16 ) - SKP_LSHIFT( psEncCtrl->input_quality_Q14, 2 ), SKP_FIX_CONST( LOW_INPUT_QUALITY_HARMONIC_BOOST, 16 ) );

    if( USE_HARM_SHAPING && psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) {
        /* More harmonic noise shaping for high bitrates or noisy input */
        HarmShapeGain_Q16 = SKP_SMLAWB( SKP_FIX_CONST( HARMONIC_SHAPING, 16 ), 
                SKP_FIX_CONST( 1.0, 16 ) - SKP_SMULWB( SKP_FIX_CONST( 1.0, 18 ) - SKP_LSHIFT( psEncCtrl->coding_quality_Q14, 4 ),
                psEncCtrl->input_quality_Q14 ), SKP_FIX_CONST( HIGH_RATE_OR_LOW_QUALITY_HARMONIC_SHAPING, 16 ) );

        /* Less harmonic noise shaping for less periodic signals */
        HarmShapeGain_Q16 = SKP_SMULWB( SKP_LSHIFT( HarmShapeGain_Q16, 1 ), 
            SKP_Silk_SQRT_APPROX( SKP_LSHIFT( psEnc->LTPCorr_Q15, 15 ) ) );
    } else {
        HarmShapeGain_Q16 = 0;
    }

    /*************************/
    /* Smooth over subframes */
    /*************************/
    for( k = 0; k < NB_SUBFR; k++ ) {
        psShapeSt->HarmBoost_smth_Q16 =
            SKP_SMLAWB( psShapeSt->HarmBoost_smth_Q16,     HarmBoost_Q16     - psShapeSt->HarmBoost_smth_Q16,     SKP_FIX_CONST( SUBFR_SMTH_COEF, 16 ) );
        psShapeSt->HarmShapeGain_smth_Q16 =
            SKP_SMLAWB( psShapeSt->HarmShapeGain_smth_Q16, HarmShapeGain_Q16 - psShapeSt->HarmShapeGain_smth_Q16, SKP_FIX_CONST( SUBFR_SMTH_COEF, 16 ) );
        psShapeSt->Tilt_smth_Q16 =
            SKP_SMLAWB( psShapeSt->Tilt_smth_Q16,          Tilt_Q16          - psShapeSt->Tilt_smth_Q16,          SKP_FIX_CONST( SUBFR_SMTH_COEF, 16 ) );

        psEncCtrl->HarmBoost_Q14[ k ]     = ( SKP_int )SKP_RSHIFT_ROUND( psShapeSt->HarmBoost_smth_Q16,     2 );
        psEncCtrl->HarmShapeGain_Q14[ k ] = ( SKP_int )SKP_RSHIFT_ROUND( psShapeSt->HarmShapeGain_smth_Q16, 2 );
        psEncCtrl->Tilt_Q14[ k ]          = ( SKP_int )SKP_RSHIFT_ROUND( psShapeSt->Tilt_smth_Q16,          2 );
    }
}