Example #1
0
/* Glues concealed frames with new good recieved frames             */
void SKP_Silk_PLC_glue_frames(
    SKP_Silk_decoder_state      *psDec,             /* I/O decoder state    */
    SKP_Silk_decoder_control    *psDecCtrl,         /* I/O Decoder control  */
    SKP_int16                   signal[],           /* I/O signal           */
    SKP_int                     length              /* I length of residual */
)
{
    SKP_int   i, energy_shift;
    SKP_int32 energy;
    SKP_Silk_PLC_struct *psPLC;
    psPLC = &psDec->sPLC;

    if( psDec->lossCnt ) {
        /* Calculate energy in concealed residual */
        SKP_Silk_sum_sqr_shift( &psPLC->conc_energy, &psPLC->conc_energy_shift, signal, length );

        psPLC->last_frame_lost = 1;
    } else {
        if( psDec->sPLC.last_frame_lost ) {
            /* Calculate residual in decoded signal if last frame was lost */
            SKP_Silk_sum_sqr_shift( &energy, &energy_shift, signal, length );

            /* Normalize energies */
            if( energy_shift > psPLC->conc_energy_shift ) {
                psPLC->conc_energy = SKP_RSHIFT( psPLC->conc_energy, energy_shift - psPLC->conc_energy_shift );
            } else if( energy_shift < psPLC->conc_energy_shift ) {
                energy = SKP_RSHIFT( energy, psPLC->conc_energy_shift - energy_shift );
            }

            /* Fade in the energy difference */
            if( energy > psPLC->conc_energy ) {
                SKP_int32 frac_Q24, LZ;
                SKP_int32 gain_Q12, slope_Q12;

                LZ = SKP_Silk_CLZ32( psPLC->conc_energy );
                LZ = LZ - 1;
                psPLC->conc_energy = SKP_LSHIFT( psPLC->conc_energy, LZ );
                energy = SKP_RSHIFT( energy, SKP_max_32( 24 - LZ, 0 ) );

                frac_Q24 = SKP_DIV32( psPLC->conc_energy, SKP_max( energy, 1 ) );

                gain_Q12 = SKP_Silk_SQRT_APPROX( frac_Q24 );
                slope_Q12 = SKP_DIV32_16( ( 1 << 12 ) - gain_Q12, length );

                for( i = 0; i < length; i++ ) {
                    signal[ i ] = SKP_RSHIFT( SKP_MUL( gain_Q12, signal[ i ] ), 12 );
                    gain_Q12 += slope_Q12;
                    gain_Q12 = SKP_min( gain_Q12, ( 1 << 12 ) );
                }
            }
        }
        psPLC->last_frame_lost = 0;

    }
}
/* Laroia low complexity NLSF weights */
void SKP_Silk_NLSF_VQ_weights_laroia(
    SKP_int             *pNLSFW_Q6,         /* O: Pointer to input vector weights           [D x 1]     */
    const SKP_int       *pNLSF_Q15,         /* I: Pointer to input vector                   [D x 1]     */
    const SKP_int       D                   /* I: Input vector dimension (even)                         */
)
{
    SKP_int   k;
    SKP_int32 tmp1_int, tmp2_int;

    /* Check that we are guaranteed to end up within the required range */
    SKP_assert( D > 0 );
    SKP_assert( ( D & 1 ) == 0 );

    /* First value */
    tmp1_int = SKP_max_int( pNLSF_Q15[ 0 ], MIN_NDELTA );
    tmp1_int = SKP_DIV32_16( 1 << ( 15 + Q_OUT ), tmp1_int );
    tmp2_int = SKP_max_int( pNLSF_Q15[ 1 ] - pNLSF_Q15[ 0 ], MIN_NDELTA );
    tmp2_int = SKP_DIV32_16( 1 << ( 15 + Q_OUT ), tmp2_int );
    pNLSFW_Q6[ 0 ] = (SKP_int)SKP_min_int( tmp1_int + tmp2_int, SKP_int16_MAX );
    SKP_assert( pNLSFW_Q6[ 0 ] > 0 );

    /* Main loop */
    for( k = 1; k < D - 1; k += 2 ) {
        tmp1_int = SKP_max_int( pNLSF_Q15[ k + 1 ] - pNLSF_Q15[ k ], MIN_NDELTA );
        tmp1_int = SKP_DIV32_16( 1 << ( 15 + Q_OUT ), tmp1_int );
        pNLSFW_Q6[ k ] = (SKP_int)SKP_min_int( tmp1_int + tmp2_int, SKP_int16_MAX );
        SKP_assert( pNLSFW_Q6[ k ] > 0 );

        tmp2_int = SKP_max_int( pNLSF_Q15[ k + 2 ] - pNLSF_Q15[ k + 1 ], MIN_NDELTA );
        tmp2_int = SKP_DIV32_16( 1 << ( 15 + Q_OUT ), tmp2_int );
        pNLSFW_Q6[ k + 1 ] = (SKP_int)SKP_min_int( tmp1_int + tmp2_int, SKP_int16_MAX );
        SKP_assert( pNLSFW_Q6[ k + 1 ] > 0 );
    }

    /* Last value */
    tmp1_int = SKP_max_int( ( 1 << 15 ) - pNLSF_Q15[ D - 1 ], MIN_NDELTA );
    tmp1_int = SKP_DIV32_16( 1 << ( 15 + Q_OUT ), tmp1_int );
    pNLSFW_Q6[ D - 1 ] = (SKP_int)SKP_min_int( tmp1_int + tmp2_int, SKP_int16_MAX );
    SKP_assert( pNLSFW_Q6[ D - 1 ] > 0 );
}
Example #3
0
/* uses SMLAWB(), requiring armv5E and higher.                          */ 
void SKP_Silk_schur(
    SKP_int16            *rc_Q15,                /* O:    reflection coefficients [order] Q15         */
    const SKP_int32      *c,                     /* I:    correlations [order+1]                      */
    const SKP_int32      order                   /* I:    prediction order                            */
)
{
    SKP_int        k, n, lz;
    SKP_int32    C[ SKP_Silk_MAX_ORDER_LPC + 1 ][ 2 ];
    SKP_int32    Ctmp1, Ctmp2, rc_tmp_Q15;

    /* Get number of leading zeros */
    lz = SKP_Silk_CLZ32( c[ 0 ] );

    /* Copy correlations and adjust level to Q30 */
    if( lz < 2 ) {
        /* lz must be 1, so shift one to the right */
        for( k = 0; k < order + 1; k++ ) {
            C[ k ][ 0 ] = C[ k ][ 1 ] = SKP_RSHIFT( c[ k ], 1 );
        }
    } else if( lz > 2 ) {
        /* Shift to the left */
        lz -= 2; 
        for( k = 0; k < order + 1; k++ ) {
            C[ k ][ 0 ] = C[ k ][ 1 ] = SKP_LSHIFT( c[k], lz );
        }
    } else {
        /* No need to shift */
        for( k = 0; k < order + 1; k++ ) {
            C[ k ][ 0 ] = C[ k ][ 1 ] = c[ k ];
        }
    }

    for( k = 0; k < order; k++ ) {
        
        /* Get reflection coefficient */
        rc_tmp_Q15 = -SKP_DIV32_16( C[ k + 1 ][ 0 ], SKP_max_32( SKP_RSHIFT( C[ 0 ][ 1 ], 15 ), 1 ) );

        /* Clip (shouldn't happen for properly conditioned inputs) */
        rc_tmp_Q15 = SKP_SAT16( rc_tmp_Q15 );

        /* Store */
        rc_Q15[ k ] = (SKP_int16)rc_tmp_Q15;

        /* Update correlations */
        for( n = 0; n < order - k; n++ ) {
            Ctmp1 = C[ n + k + 1 ][ 0 ];
            Ctmp2 = C[ n ][ 1 ];
            C[ n + k + 1 ][ 0 ] = SKP_SMLAWB( Ctmp1, SKP_LSHIFT( Ctmp2, 1 ), rc_tmp_Q15 );
            C[ n ][ 1 ]         = SKP_SMLAWB( Ctmp2, SKP_LSHIFT( Ctmp1, 1 ), rc_tmp_Q15 );
        }
    }
}
/* Laroia low complexity NLSF weights */
void SKP_Silk_NLSF_VQ_weights_laroia(
    SKP_int16           *pNLSFW_Q5,         /* O: Pointer to input vector weights           [D x 1]     */
    const SKP_int16     *pNLSF_Q15,         /* I: Pointer to input vector                   [D x 1]     */ 
    const SKP_int       D                   /* I: Input vector dimension (even)                         */
)
{
    SKP_int   k;
    SKP_int32 tmp1_int, tmp2_int;
    
    SKP_assert( D > 0 );
    SKP_assert( ( D & 1 ) == 0 );
    
    /* First value */
    tmp1_int = SKP_max_int( pNLSF_Q15[ 0 ], 1 );
    tmp1_int = SKP_DIV32_16( 1 << ( 15 + Q_OUT ), tmp1_int );
    tmp2_int = SKP_max_int( pNLSF_Q15[ 1 ] - pNLSF_Q15[ 0 ], 1 );
    tmp2_int = SKP_DIV32_16( 1 << ( 15 + Q_OUT ), tmp2_int );
    pNLSFW_Q5[ 0 ] = (SKP_int16)SKP_min_int( tmp1_int + tmp2_int, SKP_int16_MAX );
    SKP_assert( pNLSFW_Q5[ 0 ] > 0 );
    
    /* Main loop */
    for( k = 1; k < D - 1; k += 2 ) {
        tmp1_int = SKP_max_int( pNLSF_Q15[ k + 1 ] - pNLSF_Q15[ k ], 1 );
        tmp1_int = SKP_DIV32_16( 1 << ( 15 + Q_OUT ), tmp1_int );
        pNLSFW_Q5[ k ] = (SKP_int16)SKP_min_int( tmp1_int + tmp2_int, SKP_int16_MAX );
        SKP_assert( pNLSFW_Q5[ k ] > 0 );

        tmp2_int = SKP_max_int( pNLSF_Q15[ k + 2 ] - pNLSF_Q15[ k + 1 ], 1 );
        tmp2_int = SKP_DIV32_16( 1 << ( 15 + Q_OUT ), tmp2_int );
        pNLSFW_Q5[ k + 1 ] = (SKP_int16)SKP_min_int( tmp1_int + tmp2_int, SKP_int16_MAX );
        SKP_assert( pNLSFW_Q5[ k + 1 ] > 0 );
    }
    
    /* Last value */
    tmp1_int = SKP_max_int( ( 1 << 15 ) - pNLSF_Q15[ D - 1 ], 1 );
    tmp1_int = SKP_DIV32_16( 1 << ( 15 + Q_OUT ), tmp1_int );
    pNLSFW_Q5[ D - 1 ] = (SKP_int16)SKP_min_int( tmp1_int + tmp2_int, SKP_int16_MAX );
    SKP_assert( pNLSFW_Q5[ D - 1 ] > 0 );
}
/* Convert adaptive Mid/Side representation to Left/Right stereo signal */
void silk_stereo_MS_to_LR( 
    stereo_dec_state    *state,                         /* I/O  State                                       */
    opus_int16           x1[],                           /* I/O  Left input signal, becomes mid signal       */
    opus_int16           x2[],                           /* I/O  Right input signal, becomes side signal     */
    const opus_int32     pred_Q13[],                     /* I    Predictors                                  */
    opus_int             fs_kHz,                         /* I    Samples rate (kHz)                          */
    opus_int             frame_length                    /* I    Number of samples                           */
)
{
    opus_int   n, denom_Q16, delta0_Q13, delta1_Q13;
    opus_int32 sum, diff, pred0_Q13, pred1_Q13;

    /* Buffering */
    SKP_memcpy( x1, state->sMid,  2 * sizeof( opus_int16 ) );
    SKP_memcpy( x2, state->sSide, 2 * sizeof( opus_int16 ) );
    SKP_memcpy( state->sMid,  &x1[ frame_length ], 2 * sizeof( opus_int16 ) );
    SKP_memcpy( state->sSide, &x2[ frame_length ], 2 * sizeof( opus_int16 ) );

    /* Interpolate predictors and add prediction to side channel */
    pred0_Q13  = state->pred_prev_Q13[ 0 ];
    pred1_Q13  = state->pred_prev_Q13[ 1 ];
    denom_Q16  = SKP_DIV32_16( 1 << 16, STEREO_INTERP_LEN_MS * fs_kHz );
    delta0_Q13 = SKP_RSHIFT_ROUND( SKP_SMULBB( pred_Q13[ 0 ] - state->pred_prev_Q13[ 0 ], denom_Q16 ), 16 );
    delta1_Q13 = SKP_RSHIFT_ROUND( SKP_SMULBB( pred_Q13[ 1 ] - state->pred_prev_Q13[ 1 ], denom_Q16 ), 16 );
    for( n = 0; n < STEREO_INTERP_LEN_MS * fs_kHz; n++ ) {
        pred0_Q13 += delta0_Q13;
        pred1_Q13 += delta1_Q13;
        sum = SKP_LSHIFT( SKP_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 );         /* Q11 */ 
        sum = SKP_SMLAWB( SKP_LSHIFT( ( opus_int32 )x2[ n + 1 ], 8 ), sum, pred0_Q13 );          /* Q8  */
        sum = SKP_SMLAWB( sum, SKP_LSHIFT( ( opus_int32 )x1[ n + 1 ], 11 ), pred1_Q13 );         /* Q8  */
        x2[ n + 1 ] = (opus_int16)SKP_SAT16( SKP_RSHIFT_ROUND( sum, 8 ) );
    }
    pred0_Q13 = pred_Q13[ 0 ];
    pred1_Q13 = pred_Q13[ 1 ];
    for( n = STEREO_INTERP_LEN_MS * fs_kHz; n < frame_length; n++ ) {
        sum = SKP_LSHIFT( SKP_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 );         /* Q11 */ 
        sum = SKP_SMLAWB( SKP_LSHIFT( ( opus_int32 )x2[ n + 1 ], 8 ), sum, pred0_Q13 );          /* Q8  */
        sum = SKP_SMLAWB( sum, SKP_LSHIFT( ( opus_int32 )x1[ n + 1 ], 11 ), pred1_Q13 );         /* Q8  */
        x2[ n + 1 ] = (opus_int16)SKP_SAT16( SKP_RSHIFT_ROUND( sum, 8 ) );
    }
    state->pred_prev_Q13[ 0 ] = pred_Q13[ 0 ];
    state->pred_prev_Q13[ 1 ] = pred_Q13[ 1 ];

    /* Convert to left/right signals */
    for( n = 0; n < frame_length; n++ ) {
        sum  = x1[ n + 1 ] + (opus_int32)x2[ n + 1 ];
        diff = x1[ n + 1 ] - (opus_int32)x2[ n + 1 ];
        x1[ n + 1 ] = (opus_int16)SKP_SAT16( sum );
        x2[ n + 1 ] = (opus_int16)SKP_SAT16( diff );
    }
}
Example #6
0
void SKP_Silk_CNG_Reset(SKP_Silk_decoder_state * psDec	/* I/O  Decoder state                               */
    )
{
	int i, NLSF_step_Q15, NLSF_acc_Q15;

	NLSF_step_Q15 = SKP_DIV32_16(int16_t_MAX, psDec->LPC_order + 1);
	NLSF_acc_Q15 = 0;
	for (i = 0; i < psDec->LPC_order; i++) {
		NLSF_acc_Q15 += NLSF_step_Q15;
		psDec->sCNG.CNG_smth_NLSF_Q15[i] = NLSF_acc_Q15;
	}
	psDec->sCNG.CNG_smth_Gain_Q16 = 0;
	psDec->sCNG.rand_seed = 3176576;
}
/* Processing of gains */
void silk_process_gains_FIX(
    silk_encoder_state_FIX      *psEnc,         /* I/O  Encoder state_FIX                           */
    silk_encoder_control_FIX    *psEncCtrl      /* I/O  Encoder control_FIX                         */
)
{
    silk_shape_state_FIX    *psShapeSt = &psEnc->sShape;
    opus_int     k;
    opus_int32   s_Q16, InvMaxSqrVal_Q16, gain, gain_squared, ResNrg, ResNrgPart, quant_offset_Q10;

    /* Gain reduction when LTP coding gain is high */
    if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
        /*s = -0.5f * SKP_sigmoid( 0.25f * ( psEncCtrl->LTPredCodGain - 12.0f ) ); */
        s_Q16 = -silk_sigm_Q15( SKP_RSHIFT_ROUND( psEncCtrl->LTPredCodGain_Q7 - SILK_FIX_CONST( 12.0, 7 ), 4 ) );
        for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
            psEncCtrl->Gains_Q16[ k ] = SKP_SMLAWB( psEncCtrl->Gains_Q16[ k ], psEncCtrl->Gains_Q16[ k ], s_Q16 );
        }
    }

    /* Limit the quantized signal */
    /* InvMaxSqrVal = pow( 2.0f, 0.33f * ( 21.0f - SNR_dB ) ) / subfr_length; */
    InvMaxSqrVal_Q16 = SKP_DIV32_16( silk_log2lin(
                                         SKP_SMULWB( SILK_FIX_CONST( 21 + 16 / 0.33, 7 ) - psEnc->sCmn.SNR_dB_Q7, SILK_FIX_CONST( 0.33, 16 ) ) ), psEnc->sCmn.subfr_length );

    for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
        /* Soft limit on ratio residual energy and squared gains */
        ResNrg     = psEncCtrl->ResNrg[ k ];
        ResNrgPart = SKP_SMULWW( ResNrg, InvMaxSqrVal_Q16 );
        if( psEncCtrl->ResNrgQ[ k ] > 0 ) {
            ResNrgPart = SKP_RSHIFT_ROUND( ResNrgPart, psEncCtrl->ResNrgQ[ k ] );
        } else {
            if( ResNrgPart >= SKP_RSHIFT( SKP_int32_MAX, -psEncCtrl->ResNrgQ[ k ] ) ) {
                ResNrgPart = SKP_int32_MAX;
            } else {
                ResNrgPart = SKP_LSHIFT( ResNrgPart, -psEncCtrl->ResNrgQ[ k ] );
            }
        }
        gain = psEncCtrl->Gains_Q16[ k ];
        gain_squared = SKP_ADD_SAT32( ResNrgPart, SKP_SMMUL( gain, gain ) );
        if( gain_squared < SKP_int16_MAX ) {
            /* recalculate with higher precision */
            gain_squared = SKP_SMLAWW( SKP_LSHIFT( ResNrgPart, 16 ), gain, gain );
            SKP_assert( gain_squared > 0 );
            gain = silk_SQRT_APPROX( gain_squared );                    /* Q8   */
            gain = SKP_min( gain, SKP_int32_MAX >> 8 );
            psEncCtrl->Gains_Q16[ k ] = SKP_LSHIFT_SAT32( gain, 8 );        /* Q16  */
        } else {
void SKP_Silk_LTP_scale_ctrl_FIX(
    SKP_Silk_encoder_state_FIX      *psEnc,     /* I/O  encoder state FIX                           */
    SKP_Silk_encoder_control_FIX    *psEncCtrl  /* I/O  encoder control FIX                         */
)
{
    SKP_int round_loss, frames_per_packet;
    SKP_int g_out_Q5, g_limit_Q15, thrld1_Q15, thrld2_Q15;

    /* 1st order high-pass filter */
    psEnc->HPLTPredCodGain_Q7 = SKP_max_int( psEncCtrl->LTPredCodGain_Q7 - psEnc->prevLTPredCodGain_Q7, 0 ) 
        + SKP_RSHIFT_ROUND( psEnc->HPLTPredCodGain_Q7, 1 );
    
    psEnc->prevLTPredCodGain_Q7 = psEncCtrl->LTPredCodGain_Q7;

    /* combine input and filtered input */
    g_out_Q5    = SKP_RSHIFT_ROUND( SKP_RSHIFT( psEncCtrl->LTPredCodGain_Q7, 1 ) + SKP_RSHIFT( psEnc->HPLTPredCodGain_Q7, 1 ), 3 );
    g_limit_Q15 = SKP_Silk_sigm_Q15( g_out_Q5 - ( 3 << 5 ) );
            
    /* Default is minimum scaling */
    psEncCtrl->sCmn.LTP_scaleIndex = 0;

    /* Round the loss measure to whole pct */
    round_loss = ( SKP_int )psEnc->sCmn.PacketLoss_perc;

    /* Only scale if first frame in packet 0% */
    if( psEnc->sCmn.nFramesInPayloadBuf == 0 ) {
        
        frames_per_packet = SKP_DIV32_16( psEnc->sCmn.PacketSize_ms, FRAME_LENGTH_MS );

        round_loss += frames_per_packet - 1;
        thrld1_Q15 = LTPScaleThresholds_Q15[ SKP_min_int( round_loss,     NB_THRESHOLDS - 1 ) ];
        thrld2_Q15 = LTPScaleThresholds_Q15[ SKP_min_int( round_loss + 1, NB_THRESHOLDS - 1 ) ];
    
        if( g_limit_Q15 > thrld1_Q15 ) {
            /* Maximum scaling */
            psEncCtrl->sCmn.LTP_scaleIndex = 2;
        } else if( g_limit_Q15 > thrld2_Q15 ) {
            /* Medium scaling */
            psEncCtrl->sCmn.LTP_scaleIndex = 1;
        }
    }
    psEncCtrl->LTP_scale_Q14 = SKP_Silk_LTPScales_table_Q14[ psEncCtrl->sCmn.LTP_scaleIndex ];
}
Example #9
0
void silk_NLSF_decode(
          opus_int16             *pNLSF_Q15,             /* O    Quantized NLSF vector [ LPC_ORDER ]     */
          opus_int8              *NLSFIndices,           /* I    Codebook path vector [ LPC_ORDER + 1 ]  */
    const silk_NLSF_CB_struct   *psNLSF_CB              /* I    Codebook object                         */
)
{
    opus_int         i;
    opus_uint8       pred_Q8[  MAX_LPC_ORDER ];
    opus_int16       ec_ix[    MAX_LPC_ORDER ];
    opus_int16       res_Q10[  MAX_LPC_ORDER ];
    opus_int16       W_tmp_QW[ MAX_LPC_ORDER ];
    opus_int32       W_tmp_Q9, NLSF_Q15_tmp;
    const opus_uint8 *pCB_element;

    /* Decode first stage */
    pCB_element = &psNLSF_CB->CB1_NLSF_Q8[ NLSFIndices[ 0 ] * psNLSF_CB->order ];
    for( i = 0; i < psNLSF_CB->order; i++ ) {
        pNLSF_Q15[ i ] = SKP_LSHIFT( ( opus_int16 )pCB_element[ i ], 7 );
    }

    /* Unpack entropy table indices and predictor for current CB1 index */
    silk_NLSF_unpack( ec_ix, pred_Q8, psNLSF_CB, NLSFIndices[ 0 ] );

    /* Trellis dequantizer */
    silk_NLSF_residual_dequant( res_Q10, &NLSFIndices[ 1 ], pred_Q8, psNLSF_CB->quantStepSize_Q16, psNLSF_CB->order );

    /* Weights from codebook vector */
    silk_NLSF_VQ_weights_laroia( W_tmp_QW, pNLSF_Q15, psNLSF_CB->order );

    /* Apply inverse square-rooted weights and add to output */
    for( i = 0; i < psNLSF_CB->order; i++ ) {
        W_tmp_Q9 = silk_SQRT_APPROX( SKP_LSHIFT( ( opus_int32 )W_tmp_QW[ i ], 18 - NLSF_W_Q ) );
        NLSF_Q15_tmp = SKP_ADD32( pNLSF_Q15[ i ], SKP_DIV32_16( SKP_LSHIFT( ( opus_int32 )res_Q10[ i ], 14 ), W_tmp_Q9 ) );
        pNLSF_Q15[ i ] = (opus_int16)SKP_LIMIT( NLSF_Q15_tmp, 0, 32767 );
    }

    /* NLSF stabilization */
    silk_NLSF_stabilize( pNLSF_Q15, psNLSF_CB->deltaMin_Q15, psNLSF_CB->order );
}
Example #10
0
/* Deactivate by setting psEncC->mode = 0;                  */
void silk_LP_variable_cutoff(
    silk_LP_state           *psLP,              /* I/O  LP filter state                             */
    SKP_int16                   *signal,            /* I/O  Low-pass filtered output signal             */
    const SKP_int               frame_length        /* I    Frame length                                */
)
{
    SKP_int32   B_Q28[ TRANSITION_NB ], A_Q28[ TRANSITION_NA ], fac_Q16 = 0;
    SKP_int     ind = 0;

    SKP_assert( psLP->transition_frame_no >= 0 && psLP->transition_frame_no <= TRANSITION_FRAMES );

    /* Run filter if needed */
    if( psLP->mode != 0 ) {
        /* Calculate index and interpolation factor for interpolation */
#if( TRANSITION_INT_STEPS == 64 )
        fac_Q16 = SKP_LSHIFT( TRANSITION_FRAMES - psLP->transition_frame_no, 16 - 6 );
#else
        fac_Q16 = SKP_DIV32_16( SKP_LSHIFT( TRANSITION_FRAMES - psLP->transition_frame_no, 16 ), TRANSITION_FRAMES );
#endif
        ind      = SKP_RSHIFT( fac_Q16, 16 );
        fac_Q16 -= SKP_LSHIFT( ind, 16 );

        SKP_assert( ind >= 0 );
        SKP_assert( ind < TRANSITION_INT_NUM );

        /* Interpolate filter coefficients */
        silk_LP_interpolate_filter_taps( B_Q28, A_Q28, ind, fac_Q16 );

        /* Update transition frame number for next frame */
        psLP->transition_frame_no = SKP_LIMIT( psLP->transition_frame_no + psLP->mode, 0, TRANSITION_FRAMES );

        /* ARMA low-pass filtering */
        SKP_assert( TRANSITION_NB == 3 && TRANSITION_NA == 2 );
        silk_biquad_alt( signal, B_Q28, A_Q28, psLP->In_LP_State, signal, frame_length );
    }
}
Example #11
0
SKP_int SKP_Silk_VAD_GetSA_Q8(                      /* O    Return value, 0 if success                  */
    SKP_Silk_encoder_state      *psEncC,            /* I/O  Encoder state                               */
    const SKP_int16             pIn[]               /* I    PCM input                                   */
)
{
    SKP_int   SA_Q15, pSNR_dB_Q7, input_tilt;
    SKP_int   decimated_framelength, dec_subframe_length, dec_subframe_offset, SNR_Q7, i, b, s;
    SKP_int32 sumSquared, smooth_coef_Q16;
    SKP_int16 HPstateTmp;
    SKP_int16 X[ VAD_N_BANDS ][ MAX_FRAME_LENGTH / 2 ];
    SKP_int32 Xnrg[ VAD_N_BANDS ];
    SKP_int32 NrgToNoiseRatio_Q8[ VAD_N_BANDS ];
    SKP_int32 speech_nrg, x_tmp;
    SKP_int   ret = 0;
    SKP_Silk_VAD_state *psSilk_VAD = &psEncC->sVAD;

    /* Safety checks */
    SKP_assert( VAD_N_BANDS == 4 );
    SKP_assert( MAX_FRAME_LENGTH >= psEncC->frame_length );
    SKP_assert( psEncC->frame_length <= 512 );
    SKP_assert( psEncC->frame_length == 8 * SKP_RSHIFT( psEncC->frame_length, 3 ) );

    /***********************/
    /* Filter and Decimate */
    /***********************/
    /* 0-8 kHz to 0-4 kHz and 4-8 kHz */
    SKP_Silk_ana_filt_bank_1( pIn,          &psSilk_VAD->AnaState[  0 ], &X[ 0 ][ 0 ], &X[ 3 ][ 0 ], psEncC->frame_length );        
    
    /* 0-4 kHz to 0-2 kHz and 2-4 kHz */
    SKP_Silk_ana_filt_bank_1( &X[ 0 ][ 0 ], &psSilk_VAD->AnaState1[ 0 ], &X[ 0 ][ 0 ], &X[ 2 ][ 0 ], SKP_RSHIFT( psEncC->frame_length, 1 ) );
    
    /* 0-2 kHz to 0-1 kHz and 1-2 kHz */
    SKP_Silk_ana_filt_bank_1( &X[ 0 ][ 0 ], &psSilk_VAD->AnaState2[ 0 ], &X[ 0 ][ 0 ], &X[ 1 ][ 0 ], SKP_RSHIFT( psEncC->frame_length, 2 ) );

    /*********************************************/
    /* HP filter on lowest band (differentiator) */
    /*********************************************/
    decimated_framelength = SKP_RSHIFT( psEncC->frame_length, 3 );
    X[ 0 ][ decimated_framelength - 1 ] = SKP_RSHIFT( X[ 0 ][ decimated_framelength - 1 ], 1 );
    HPstateTmp = X[ 0 ][ decimated_framelength - 1 ];
    for( i = decimated_framelength - 1; i > 0; i-- ) {
        X[ 0 ][ i - 1 ]  = SKP_RSHIFT( X[ 0 ][ i - 1 ], 1 );
        X[ 0 ][ i ]     -= X[ 0 ][ i - 1 ];
    }
    X[ 0 ][ 0 ] -= psSilk_VAD->HPstate;
    psSilk_VAD->HPstate = HPstateTmp;

    /*************************************/
    /* Calculate the energy in each band */
    /*************************************/
    for( b = 0; b < VAD_N_BANDS; b++ ) {        
        /* Find the decimated framelength in the non-uniformly divided bands */
        decimated_framelength = SKP_RSHIFT( psEncC->frame_length, SKP_min_int( VAD_N_BANDS - b, VAD_N_BANDS - 1 ) );

        /* Split length into subframe lengths */
        dec_subframe_length = SKP_RSHIFT( decimated_framelength, VAD_INTERNAL_SUBFRAMES_LOG2 );
        dec_subframe_offset = 0;

        /* Compute energy per sub-frame */
        /* initialize with summed energy of last subframe */
        Xnrg[ b ] = psSilk_VAD->XnrgSubfr[ b ];
        for( s = 0; s < VAD_INTERNAL_SUBFRAMES; s++ ) {
            sumSquared = 0;
            for( i = 0; i < dec_subframe_length; i++ ) {
                /* The energy will be less than dec_subframe_length * ( SKP_int16_MIN / 8 ) ^ 2.            */
                /* Therefore we can accumulate with no risk of overflow (unless dec_subframe_length > 128)  */
                x_tmp = SKP_RSHIFT( X[ b ][ i + dec_subframe_offset ], 3 );
                sumSquared = SKP_SMLABB( sumSquared, x_tmp, x_tmp );

                /* Safety check */
                SKP_assert( sumSquared >= 0 );
            }

            /* Add/saturate summed energy of current subframe */
            if( s < VAD_INTERNAL_SUBFRAMES - 1 ) {
                Xnrg[ b ] = SKP_ADD_POS_SAT32( Xnrg[ b ], sumSquared );
            } else {
                /* Look-ahead subframe */
                Xnrg[ b ] = SKP_ADD_POS_SAT32( Xnrg[ b ], SKP_RSHIFT( sumSquared, 1 ) );
            }

            dec_subframe_offset += dec_subframe_length;
        }
        psSilk_VAD->XnrgSubfr[ b ] = sumSquared; 
    }

    /********************/
    /* Noise estimation */
    /********************/
    SKP_Silk_VAD_GetNoiseLevels( &Xnrg[ 0 ], psSilk_VAD );

    /***********************************************/
    /* Signal-plus-noise to noise ratio estimation */
    /***********************************************/
    sumSquared = 0;
    input_tilt = 0;
    for( b = 0; b < VAD_N_BANDS; b++ ) {
        speech_nrg = Xnrg[ b ] - psSilk_VAD->NL[ b ];
        if( speech_nrg > 0 ) {
            /* Divide, with sufficient resolution */
            if( ( Xnrg[ b ] & 0xFF800000 ) == 0 ) {
                NrgToNoiseRatio_Q8[ b ] = SKP_DIV32( SKP_LSHIFT( Xnrg[ b ], 8 ), psSilk_VAD->NL[ b ] + 1 );
            } else {
                NrgToNoiseRatio_Q8[ b ] = SKP_DIV32( Xnrg[ b ], SKP_RSHIFT( psSilk_VAD->NL[ b ], 8 ) + 1 );
            }

            /* Convert to log domain */
            SNR_Q7 = SKP_Silk_lin2log( NrgToNoiseRatio_Q8[ b ] ) - 8 * 128;

            /* Sum-of-squares */
            sumSquared = SKP_SMLABB( sumSquared, SNR_Q7, SNR_Q7 );          /* Q14 */

            /* Tilt measure */
            if( speech_nrg < ( 1 << 20 ) ) {
                /* Scale down SNR value for small subband speech energies */
                SNR_Q7 = SKP_SMULWB( SKP_LSHIFT( SKP_Silk_SQRT_APPROX( speech_nrg ), 6 ), SNR_Q7 );
            }
            input_tilt = SKP_SMLAWB( input_tilt, tiltWeights[ b ], SNR_Q7 );
        } else {
            NrgToNoiseRatio_Q8[ b ] = 256;
        }
    }

    /* Mean-of-squares */
    sumSquared = SKP_DIV32_16( sumSquared, VAD_N_BANDS ); /* Q14 */

    /* Root-mean-square approximation, scale to dBs, and write to output pointer */
    pSNR_dB_Q7 = ( SKP_int16 )( 3 * SKP_Silk_SQRT_APPROX( sumSquared ) ); /* Q7 */

    /*********************************/
    /* Speech Probability Estimation */
    /*********************************/
    SA_Q15 = SKP_Silk_sigm_Q15( SKP_SMULWB( VAD_SNR_FACTOR_Q16, pSNR_dB_Q7 ) - VAD_NEGATIVE_OFFSET_Q5 );

    /**************************/
    /* Frequency Tilt Measure */
    /**************************/
    psEncC->input_tilt_Q15 = SKP_LSHIFT( SKP_Silk_sigm_Q15( input_tilt ) - 16384, 1 );

    /**************************************************/
    /* Scale the sigmoid output based on power levels */
    /**************************************************/
    speech_nrg = 0;
    for( b = 0; b < VAD_N_BANDS; b++ ) {
        /* Accumulate signal-without-noise energies, higher frequency bands have more weight */
        speech_nrg += ( b + 1 ) * SKP_RSHIFT( Xnrg[ b ] - psSilk_VAD->NL[ b ], 4 );
    }

    /* Power scaling */
    if( speech_nrg <= 0 ) {
        SA_Q15 = SKP_RSHIFT( SA_Q15, 1 ); 
    } else if( speech_nrg < 32768 ) {
        if( psEncC->frame_length == 10 * psEncC->fs_kHz ) {
            speech_nrg = SKP_LSHIFT_SAT32( speech_nrg, 16 );
        } else {
            speech_nrg = SKP_LSHIFT_SAT32( speech_nrg, 15 );
        }

        /* square-root */
        speech_nrg = SKP_Silk_SQRT_APPROX( speech_nrg );
        SA_Q15 = SKP_SMULWB( 32768 + speech_nrg, SA_Q15 ); 
    }

    /* Copy the resulting speech activity in Q8 */
    psEncC->speech_activity_Q8 = SKP_min_int( SKP_RSHIFT( SA_Q15, 7 ), SKP_uint8_MAX );

    /***********************************/
    /* Energy Level and SNR estimation */
    /***********************************/
    /* Smoothing coefficient */
    smooth_coef_Q16 = SKP_SMULWB( VAD_SNR_SMOOTH_COEF_Q18, SKP_SMULWB( SA_Q15, SA_Q15 ) );
    
    if( psEncC->frame_length == 10 * psEncC->fs_kHz ) {
        smooth_coef_Q16 >>= 1;
    }
opus_int silk_setup_resamplers(
    silk_encoder_state_Fxx          *psEnc,             /* I/O                      */
    opus_int                         fs_kHz              /* I                        */
)
{
    opus_int   ret = SILK_NO_ERROR;
    opus_int32 nSamples_temp;
    
    if( psEnc->sCmn.fs_kHz != fs_kHz || psEnc->sCmn.prev_API_fs_Hz != psEnc->sCmn.API_fs_Hz ) 
    {
        if( psEnc->sCmn.fs_kHz == 0 ) {
            /* Initialize the resampler for enc_API.c preparing resampling from API_fs_Hz to fs_kHz */
            ret += silk_resampler_init( &psEnc->sCmn.resampler_state, psEnc->sCmn.API_fs_Hz, fs_kHz * 1000 );
        } else {
            /* Allocate worst case space for temporary upsampling, 8 to 48 kHz, so a factor 6 */
            opus_int16 x_buf_API_fs_Hz[ ( 2 * MAX_FRAME_LENGTH_MS + LA_SHAPE_MS ) * MAX_API_FS_KHZ ];
#ifdef FIXED_POINT
            opus_int16 *x_bufFIX = psEnc->x_buf;
#else
            opus_int16 x_bufFIX[ 2 * MAX_FRAME_LENGTH + LA_SHAPE_MAX ]; 
#endif

            nSamples_temp = SKP_LSHIFT( psEnc->sCmn.frame_length, 1 ) + LA_SHAPE_MS * psEnc->sCmn.fs_kHz;

#ifndef FIXED_POINT
            SKP_float2short_array( x_bufFIX, psEnc->x_buf, nSamples_temp );
#endif

            if( SKP_SMULBB( fs_kHz, 1000 ) < psEnc->sCmn.API_fs_Hz && psEnc->sCmn.fs_kHz != 0 ) {
                /* Resample buffered data in x_buf to API_fs_Hz */

                silk_resampler_state_struct  temp_resampler_state;

                /* Initialize resampler for temporary resampling of x_buf data to API_fs_Hz */
                ret += silk_resampler_init( &temp_resampler_state, SKP_SMULBB( psEnc->sCmn.fs_kHz, 1000 ), psEnc->sCmn.API_fs_Hz );

                /* Temporary resampling of x_buf data to API_fs_Hz */
                ret += silk_resampler( &temp_resampler_state, x_buf_API_fs_Hz, x_bufFIX, nSamples_temp );

                /* Calculate number of samples that has been temporarily upsampled */
                nSamples_temp = SKP_DIV32_16( nSamples_temp * psEnc->sCmn.API_fs_Hz, SKP_SMULBB( psEnc->sCmn.fs_kHz, 1000 ) );

                /* Initialize the resampler for enc_API.c preparing resampling from API_fs_Hz to fs_kHz */
                ret += silk_resampler_init( &psEnc->sCmn.resampler_state, psEnc->sCmn.API_fs_Hz, SKP_SMULBB( fs_kHz, 1000 ) );

            } else {
                /* Copy data */
                SKP_memcpy( x_buf_API_fs_Hz, x_bufFIX, nSamples_temp * sizeof( opus_int16 ) );
            }

            if( 1000 * fs_kHz != psEnc->sCmn.API_fs_Hz ) {
                /* Correct resampler state (unless resampling by a factor 1) by resampling buffered data from API_fs_Hz to fs_kHz */
                ret += silk_resampler( &psEnc->sCmn.resampler_state, x_bufFIX, x_buf_API_fs_Hz, nSamples_temp );
            }
#ifndef FIXED_POINT
            SKP_short2float_array( psEnc->x_buf, x_bufFIX, ( 2 * MAX_FRAME_LENGTH_MS + LA_SHAPE_MS ) * fs_kHz );
#endif
        }
    }

    psEnc->sCmn.prev_API_fs_Hz = psEnc->sCmn.API_fs_Hz;

    return ret;
}
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;

    SKP_int32   sqrt_nrg[ NB_SUBFR ], Qnrg_vec[ NB_SUBFR ];

    /* 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_new( 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_new( 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

        sqrt_nrg[ k ] = tmp32;
        Qnrg_vec[ k ] = Qnrg;

        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 ) );
        }
    }
/* Downsamples by a factor 3 */
void SKP_Silk_resample_1_3(
    SKP_int16            *out,       /* O:   Fs_low signal  [inLen/3]                */
    SKP_int32            *S,         /* I/O: State vector   [7]                      */
    const SKP_int16      *in,        /* I:   Fs_high signal [inLen]                  */
    const SKP_int32      inLen       /* I:   Input length, must be a multiple of 3   */
)
{
    SKP_int      k, outLen, LSubFrameIn, LSubFrameOut;
    SKP_int32    out_tmp, limit = 102258000; // (102258000 + 1560) * 21 * 2^(-16) = 32767.5
    SKP_int32    scratch0[ 3 * OUT_SUBFR_LEN ];
    SKP_int32    scratch10[ OUT_SUBFR_LEN ], scratch11[ OUT_SUBFR_LEN ], scratch12[ OUT_SUBFR_LEN ];
    /* coefficients for 3-fold resampling */
    const SKP_int16 A30[ 2 ] = {  1773, 17818 };
    const SKP_int16 A31[ 2 ] = {  4942, 25677 };
    const SKP_int16 A32[ 2 ] = { 11786, 29304 };

    /* Check that input is multiple of 3 */
    SKP_assert( inLen % 3 == 0 );

    outLen = SKP_DIV32_16( inLen, 3 );
    while( outLen > 0 ) {
        LSubFrameOut = SKP_min_int( OUT_SUBFR_LEN, outLen );
        LSubFrameIn  = SKP_SMULBB( 3, LSubFrameOut );

        /* Low-pass filter, Q15 -> Q25 */
        SKP_Silk_lowpass_short( in, S, scratch0, LSubFrameIn );

        /* De-interleave three allpass inputs */
        for( k = 0; k < LSubFrameOut; k++ ) {
            scratch10[ k ] = scratch0[ 3 * k     ];
            scratch11[ k ] = scratch0[ 3 * k + 1 ];
            scratch12[ k ] = scratch0[ 3 * k + 2 ];
        }

        /* Allpass filters */
        SKP_Silk_allpass_int( scratch10, S + 1, A32[ 0 ], scratch0,  LSubFrameOut );
        SKP_Silk_allpass_int( scratch0,  S + 2, A32[ 1 ], scratch10, LSubFrameOut );

        SKP_Silk_allpass_int( scratch11, S + 3, A31[ 0 ], scratch0,  LSubFrameOut );
        SKP_Silk_allpass_int( scratch0,  S + 4, A31[ 1 ], scratch11, LSubFrameOut );

        SKP_Silk_allpass_int( scratch12, S + 5, A30[ 0 ], scratch0,  LSubFrameOut );
        SKP_Silk_allpass_int( scratch0,  S + 6, A30[ 1 ], scratch12, LSubFrameOut );

        /* Add three allpass outputs */
        for( k = 0; k < LSubFrameOut; k++ ) {
            out_tmp = scratch10[ k ] + scratch11[ k ] + scratch12[ k ];
            if( out_tmp - limit > 0 ) {
                out[ k ] = SKP_int16_MAX;
            } else if( out_tmp + limit < 0 ) {
                out[ k ] = SKP_int16_MIN;
            } else {
                out[ k ] = (SKP_int16) SKP_SMULWB( out_tmp + 1560, 21 );
            }
        }

        in     += LSubFrameIn;
        out    += LSubFrameOut;
        outLen -= LSubFrameOut;
    }
}
/* Control internal sampling rate */
SKP_int SKP_Silk_control_audio_bandwidth(
    SKP_Silk_encoder_state      *psEncC,            /* I/O  Pointer to Silk encoder state               */
    const SKP_int32             TargetRate_bps      /* I    Target max bitrate (bps)                    */
)
{
    SKP_int fs_kHz;

    fs_kHz = psEncC->fs_kHz;
    if( fs_kHz == 0 ) {
        /* Encoder has just been initialized */
        if( TargetRate_bps >= SWB2WB_BITRATE_BPS ) {
            fs_kHz = 24;
        } else if( TargetRate_bps >= WB2MB_BITRATE_BPS ) {
            fs_kHz = 16;
        } else if( TargetRate_bps >= MB2NB_BITRATE_BPS ) {
            fs_kHz = 12;
        } else {
            fs_kHz = 8;
        }
        /* Make sure internal rate is not higher than external rate or maximum allowed, or lower than minimum allowed */
        fs_kHz = SKP_min( fs_kHz, SKP_DIV32_16( psEncC->API_fs_Hz, 1000 ) );
        fs_kHz = SKP_min( fs_kHz, psEncC->maxInternal_fs_kHz );
    } else if( SKP_SMULBB( fs_kHz, 1000 ) > psEncC->API_fs_Hz || fs_kHz > psEncC->maxInternal_fs_kHz ) {
        /* Make sure internal rate is not higher than external rate or maximum allowed */
        fs_kHz = SKP_DIV32_16( psEncC->API_fs_Hz, 1000 );
        fs_kHz = SKP_min( fs_kHz, psEncC->maxInternal_fs_kHz );
    } else {
        /* State machine for the internal sampling rate switching */
        if( psEncC->API_fs_Hz > 8000 ) {
            /* Accumulate the difference between the target rate and limit for switching down */
            psEncC->bitrateDiff += SKP_MUL( psEncC->PacketSize_ms, psEncC->TargetRate_bps - psEncC->bitrate_threshold_down );
            psEncC->bitrateDiff  = SKP_min( psEncC->bitrateDiff, 0 );

            if( psEncC->vadFlag == NO_VOICE_ACTIVITY ) { /* Low speech activity */
                /* Check if we should switch down */
#if SWITCH_TRANSITION_FILTERING 
                if( ( psEncC->sLP.transition_frame_no == 0 ) &&                         /* Transition phase not active */
                    ( psEncC->bitrateDiff <= -ACCUM_BITS_DIFF_THRESHOLD ||              /* Bitrate threshold is met */
                    ( psEncC->sSWBdetect.WB_detected * psEncC->fs_kHz == 24 ) ) ) {     /* Forced down-switching due to WB input */
                        psEncC->sLP.transition_frame_no = 1;                            /* Begin transition phase */
                        psEncC->sLP.mode                = 0;                            /* Switch down */
                } else if( 
                    ( psEncC->sLP.transition_frame_no >= TRANSITION_FRAMES_DOWN ) &&    /* Transition phase complete */
                    ( psEncC->sLP.mode == 0 ) ) {                                       /* Ready to switch down */
                        psEncC->sLP.transition_frame_no = 0;                            /* Ready for new transition phase */
#else
                if( psEncC->bitrateDiff <= -ACCUM_BITS_DIFF_THRESHOLD ) {               /* Bitrate threshold is met */ 
#endif            
                    psEncC->bitrateDiff = 0;

                    /* Switch to a lower sample frequency */
                    if( psEncC->fs_kHz == 24 ) {
                        fs_kHz = 16;
                    } else if( psEncC->fs_kHz == 16 ) {
                        fs_kHz = 12;
                    } else {
                        SKP_assert( psEncC->fs_kHz == 12 );
                        fs_kHz = 8;
                    }
                }

                /* Check if we should switch up */
                if( ( ( psEncC->fs_kHz * 1000 < psEncC->API_fs_Hz ) &&
                    ( psEncC->TargetRate_bps >= psEncC->bitrate_threshold_up ) && 
                    ( psEncC->sSWBdetect.WB_detected * psEncC->fs_kHz < 16 ) ) && 
                    ( ( ( psEncC->fs_kHz == 16 ) && ( psEncC->maxInternal_fs_kHz >= 24 ) ) || 
                    (   ( psEncC->fs_kHz == 12 ) && ( psEncC->maxInternal_fs_kHz >= 16 ) ) ||
                    (   ( psEncC->fs_kHz ==  8 ) && ( psEncC->maxInternal_fs_kHz >= 12 ) ) ) 
#if SWITCH_TRANSITION_FILTERING
                    && ( psEncC->sLP.transition_frame_no == 0 ) ) { /* No transition phase running, ready to switch */
                        psEncC->sLP.mode = 1; /* Switch up */
#else
                    ) {
#endif
                    psEncC->bitrateDiff = 0;

                    /* Switch to a higher sample frequency */
                    if( psEncC->fs_kHz == 8 ) {
                        fs_kHz = 12;
                    } else if( psEncC->fs_kHz == 12 ) {
                        fs_kHz = 16;
                    } else {
                        SKP_assert( psEncC->fs_kHz == 16 );
                        fs_kHz = 24;
                    }
                }
            }
        }
/* Resamples input data with a factor 2/3 */
void SKP_Silk_resample_2_3_coarse(int16_t * out,	/* O:   Output signal                                                                   */
				  int16_t * S,	/* I/O: Resampler state [ SigProc_Resample_2_3_coarse_NUM_FIR_COEFS - 1 ]               */
				  const int16_t * in,	/* I:   Input signal                                                                    */
				  const int frameLenIn,	/* I:   Number of input samples                                                         */
				  int16_t * scratch	/* I:   Scratch memory [ frameLenIn + SigProc_Resample_2_3_coarse_NUM_FIR_COEFS - 1 ]   */
    )
{
	int32_t n, ind, interpol_ind, tmp, index_Q16;
	int16_t *in_ptr;
	int frameLenOut;
	const int16_t *interpol_ptr;

	/* Copy buffered samples to start of scratch */
	SKP_memcpy(scratch, S,
		   (SigProc_Resample_2_3_coarse_NUM_FIR_COEFS -
		    1) * sizeof(int16_t));

	/* Then append by the input signal */
	SKP_memcpy(&scratch[SigProc_Resample_2_3_coarse_NUM_FIR_COEFS - 1], in,
		   frameLenIn * sizeof(int16_t));

	frameLenOut = SKP_DIV32_16(SKP_MUL(2, frameLenIn), 3);
	index_Q16 = 0;

	assert(frameLenIn == ((frameLenOut * 3) / 2));

	/* Interpolate */
	for (n = frameLenOut; n > 0; n--) {

		/* Integer part */
		ind = SKP_RSHIFT(index_Q16, 16);

		/* Pointer to buffered input */
		in_ptr = scratch + ind;

		/* Fractional part */
		interpol_ind =
		    (SKP_SMULWB
		     (index_Q16,
		      SigProc_Resample_2_3_coarse_NUM_INTERPOLATORS) &
		     (SigProc_Resample_2_3_coarse_NUM_INTERPOLATORS - 1));

		/* Pointer to FIR taps */
		interpol_ptr =
		    SigProc_Resample_2_3_coarse_INTERPOL[interpol_ind];

		/* Interpolate */
		/* Hardcoded for 32 FIR taps */
		assert(SigProc_Resample_2_3_coarse_NUM_FIR_COEFS == 32);
		tmp =
		    (int32_t) interpol_ptr[0] * in_ptr[0] +
		    (int32_t) interpol_ptr[1] * in_ptr[1] +
		    (int32_t) interpol_ptr[2] * in_ptr[2] +
		    (int32_t) interpol_ptr[3] * in_ptr[3] +
		    (int32_t) interpol_ptr[4] * in_ptr[4] +
		    (int32_t) interpol_ptr[5] * in_ptr[5] +
		    (int32_t) interpol_ptr[6] * in_ptr[6] +
		    (int32_t) interpol_ptr[7] * in_ptr[7] +
		    (int32_t) interpol_ptr[8] * in_ptr[8] +
		    (int32_t) interpol_ptr[9] * in_ptr[9] +
		    (int32_t) interpol_ptr[10] * in_ptr[10] +
		    (int32_t) interpol_ptr[11] * in_ptr[11] +
		    (int32_t) interpol_ptr[12] * in_ptr[12] +
		    (int32_t) interpol_ptr[13] * in_ptr[13] +
		    (int32_t) interpol_ptr[14] * in_ptr[14] +
		    (int32_t) interpol_ptr[15] * in_ptr[15] +
		    (int32_t) interpol_ptr[16] * in_ptr[16] +
		    (int32_t) interpol_ptr[17] * in_ptr[17] +
		    (int32_t) interpol_ptr[18] * in_ptr[18] +
		    (int32_t) interpol_ptr[19] * in_ptr[19] +
		    (int32_t) interpol_ptr[20] * in_ptr[20] +
		    (int32_t) interpol_ptr[21] * in_ptr[21] +
		    (int32_t) interpol_ptr[22] * in_ptr[22] +
		    (int32_t) interpol_ptr[23] * in_ptr[23] +
		    (int32_t) interpol_ptr[24] * in_ptr[24] +
		    (int32_t) interpol_ptr[25] * in_ptr[25] +
		    (int32_t) interpol_ptr[26] * in_ptr[26] +
		    (int32_t) interpol_ptr[27] * in_ptr[27] +
		    (int32_t) interpol_ptr[28] * in_ptr[28] +
		    (int32_t) interpol_ptr[29] * in_ptr[29];

		/* Round, saturate and store to output array */
		*out++ = (int16_t) SKP_SAT16(SKP_RSHIFT_ROUND(tmp, 15));

		/* Update index */
		index_Q16 += ((1 << 16) + (1 << 15));	// (3/2)_Q0;
	}

	/* Move last part of input signal to the sample buffer to prepare for the next call */
	SKP_memcpy(S,
		   &in[frameLenIn -
		       (SigProc_Resample_2_3_coarse_NUM_FIR_COEFS - 1)],
		   (SigProc_Resample_2_3_coarse_NUM_FIR_COEFS -
		    1) * sizeof(int16_t));
}
opus_int silk_setup_fs(
    silk_encoder_state_Fxx          *psEnc,             /* I/O                      */
    opus_int                         fs_kHz,             /* I                        */
    opus_int                         PacketSize_ms       /* I                        */
)
{
    opus_int ret = SILK_NO_ERROR;

    /* Set packet size */
    if( PacketSize_ms != psEnc->sCmn.PacketSize_ms ) {
        if( ( PacketSize_ms !=  10 ) &&
            ( PacketSize_ms !=  20 ) &&
            ( PacketSize_ms !=  40 ) && 
            ( PacketSize_ms !=  60 ) ) {
            ret = SILK_ENC_PACKET_SIZE_NOT_SUPPORTED;
        }
        if( PacketSize_ms <= 10 ) {
            psEnc->sCmn.nFramesPerPacket = 1;
            psEnc->sCmn.nb_subfr = PacketSize_ms == 10 ? 2 : 1;
            psEnc->sCmn.frame_length = SKP_SMULBB( PacketSize_ms, fs_kHz );
            psEnc->sCmn.pitch_LPC_win_length = SKP_SMULBB( FIND_PITCH_LPC_WIN_MS_2_SF, fs_kHz );
            if( psEnc->sCmn.fs_kHz == 8 ) {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_NB_iCDF;
            } else {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_iCDF;
            }
        } else {
            psEnc->sCmn.nFramesPerPacket = SKP_DIV32_16( PacketSize_ms, MAX_FRAME_LENGTH_MS );
            psEnc->sCmn.nb_subfr = MAX_NB_SUBFR;
            psEnc->sCmn.frame_length = SKP_SMULBB( 20, fs_kHz );
            psEnc->sCmn.pitch_LPC_win_length = SKP_SMULBB( FIND_PITCH_LPC_WIN_MS, fs_kHz );
            if( psEnc->sCmn.fs_kHz == 8 ) {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_NB_iCDF;
            } else {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_iCDF; 
            }
        }
        psEnc->sCmn.PacketSize_ms  = PacketSize_ms;
        psEnc->sCmn.TargetRate_bps = 0;         /* trigger new SNR computation */
    }

    /* Set internal sampling frequency */
    SKP_assert( fs_kHz == 8 || fs_kHz == 12 || fs_kHz == 16 );
    SKP_assert( psEnc->sCmn.nb_subfr == 2 || psEnc->sCmn.nb_subfr == 4 );
    if( psEnc->sCmn.fs_kHz != fs_kHz ) {
        /* reset part of the state */
#ifdef FIXED_POINT
        SKP_memset( &psEnc->sShape,               0, sizeof( silk_shape_state_FIX ) );
        SKP_memset( &psEnc->sPrefilt,             0, sizeof( silk_prefilter_state_FIX ) );
#else
        SKP_memset( &psEnc->sShape,               0, sizeof( silk_shape_state_FLP ) );
        SKP_memset( &psEnc->sPrefilt,             0, sizeof( silk_prefilter_state_FLP ) );
#endif
        SKP_memset( &psEnc->sCmn.sNSQ,            0, sizeof( silk_nsq_state ) );
        SKP_memset( psEnc->sCmn.prev_NLSFq_Q15,   0, sizeof( psEnc->sCmn.prev_NLSFq_Q15 ) );
        SKP_memset( &psEnc->sCmn.sLP.In_LP_State, 0, sizeof( psEnc->sCmn.sLP.In_LP_State ) );
        psEnc->sCmn.inputBufIx                  = 0;
        psEnc->sCmn.nFramesEncoded              = 0;
        psEnc->sCmn.TargetRate_bps              = 0;     /* trigger new SNR computation */

        /* Initialize non-zero parameters */
        psEnc->sCmn.prevLag                     = 100;
        psEnc->sCmn.first_frame_after_reset     = 1;
        psEnc->sPrefilt.lagPrev                 = 100;
        psEnc->sShape.LastGainIndex             = 10;
        psEnc->sCmn.sNSQ.lagPrev                = 100;
        psEnc->sCmn.sNSQ.prev_inv_gain_Q16      = 65536;

        psEnc->sCmn.fs_kHz = fs_kHz;
        if( psEnc->sCmn.fs_kHz == 8 ) {
            if( psEnc->sCmn.nb_subfr == MAX_NB_SUBFR ) {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_NB_iCDF; 
            } else {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_NB_iCDF;
            }
        } else {
            if( psEnc->sCmn.nb_subfr == MAX_NB_SUBFR ) {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_iCDF; 
            } else {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_iCDF;
            }
        }
        if( psEnc->sCmn.fs_kHz == 8 || psEnc->sCmn.fs_kHz == 12 ) {
            psEnc->sCmn.predictLPCOrder = MIN_LPC_ORDER;
            psEnc->sCmn.psNLSF_CB  = &silk_NLSF_CB_NB_MB;
        } else {
            psEnc->sCmn.predictLPCOrder = MAX_LPC_ORDER;
            psEnc->sCmn.psNLSF_CB  = &silk_NLSF_CB_WB;
        }
        psEnc->sCmn.subfr_length   = SUB_FRAME_LENGTH_MS * fs_kHz;
        psEnc->sCmn.frame_length   = SKP_SMULBB( psEnc->sCmn.subfr_length, psEnc->sCmn.nb_subfr );
        psEnc->sCmn.ltp_mem_length = SKP_SMULBB( LTP_MEM_LENGTH_MS, fs_kHz ); 
        psEnc->sCmn.la_pitch       = SKP_SMULBB( LA_PITCH_MS, fs_kHz );
        psEnc->sCmn.max_pitch_lag  = SKP_SMULBB( 18, fs_kHz );
        if( psEnc->sCmn.nb_subfr == MAX_NB_SUBFR ) {
            psEnc->sCmn.pitch_LPC_win_length = SKP_SMULBB( FIND_PITCH_LPC_WIN_MS, fs_kHz );
        } else {
            psEnc->sCmn.pitch_LPC_win_length = SKP_SMULBB( FIND_PITCH_LPC_WIN_MS_2_SF, fs_kHz );
        }
        if( psEnc->sCmn.fs_kHz == 16 ) {
            psEnc->sCmn.mu_LTP_Q9 = SILK_FIX_CONST( MU_LTP_QUANT_WB, 9 );
            psEnc->sCmn.pitch_lag_low_bits_iCDF = silk_uniform8_iCDF;
        } else if( psEnc->sCmn.fs_kHz == 12 ) {
            psEnc->sCmn.mu_LTP_Q9 = SILK_FIX_CONST( MU_LTP_QUANT_MB, 9 );
            psEnc->sCmn.pitch_lag_low_bits_iCDF = silk_uniform6_iCDF;
        } else {
            psEnc->sCmn.mu_LTP_Q9 = SILK_FIX_CONST( MU_LTP_QUANT_NB, 9 );
            psEnc->sCmn.pitch_lag_low_bits_iCDF = silk_uniform4_iCDF;
        }
    }

    /* Check that settings are valid */
    SKP_assert( ( psEnc->sCmn.subfr_length * psEnc->sCmn.nb_subfr ) == psEnc->sCmn.frame_length );
 
    return ret;
}
/* Processing of gains */
void SKP_Silk_process_gains_FIX(
    SKP_Silk_encoder_state_FIX      *psEnc,         /* I/O  Encoder state_FIX                           */
    SKP_Silk_encoder_control_FIX    *psEncCtrl      /* I/O  Encoder control_FIX                         */
)
{
    SKP_Silk_shape_state_FIX    *psShapeSt = &psEnc->sShape;
    SKP_int     k;
    SKP_int32   s_Q16, InvMaxSqrVal_Q16, gain, gain_squared, ResNrg, ResNrgPart;

    /* Gain reduction when LTP coding gain is high */
    if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) {
        /*s = -0.5f * SKP_sigmoid( 0.25f * ( psEncCtrl->LTPredCodGain - 12.0f ) ); */
        s_Q16 = -SKP_Silk_sigm_Q15( SKP_RSHIFT_ROUND( psEncCtrl->LTPredCodGain_Q7 - (12 << 7), 4 ) );
        for( k = 0; k < NB_SUBFR; k++ ) {
            psEncCtrl->Gains_Q16[ k ] = SKP_SMLAWB( psEncCtrl->Gains_Q16[ k ], psEncCtrl->Gains_Q16[ k ], s_Q16 );
        }
    }

    /* Limit the quantized signal */
    /*  69 = 21.0f + 16/0.33    */
    InvMaxSqrVal_Q16 = SKP_DIV32_16( SKP_Silk_log2lin( 
        SKP_SMULWB( (69 << 7) - psEncCtrl->current_SNR_dB_Q7, SKP_FIX_CONST( 0.33, 16 )) ), psEnc->sCmn.subfr_length );

    for( k = 0; k < NB_SUBFR; k++ ) {
        /* Soft limit on ratio residual energy and squared gains */
        ResNrg     = psEncCtrl->ResNrg[ k ];
        ResNrgPart = SKP_SMULWW( ResNrg, InvMaxSqrVal_Q16 );
        if( psEncCtrl->ResNrgQ[ k ] > 0 ) {
            if( psEncCtrl->ResNrgQ[ k ] < 32 ) {
                ResNrgPart = SKP_RSHIFT_ROUND( ResNrgPart, psEncCtrl->ResNrgQ[ k ] );
            } else {
                ResNrgPart = 0;
            }
        } else if( psEncCtrl->ResNrgQ[k] != 0 ) {
            if( ResNrgPart > SKP_RSHIFT( SKP_int32_MAX, -psEncCtrl->ResNrgQ[ k ] ) ) {
                ResNrgPart = SKP_int32_MAX;
            } else {
                ResNrgPart = SKP_LSHIFT( ResNrgPart, -psEncCtrl->ResNrgQ[ k ] );
            }
        }
        gain = psEncCtrl->Gains_Q16[ k ];
        gain_squared = SKP_ADD_SAT32( ResNrgPart, SKP_SMMUL( gain, gain ) );
        if( gain_squared < SKP_int16_MAX ) {
            /* recalculate with higher precision */
            gain_squared = SKP_SMLAWW( SKP_LSHIFT( ResNrgPart, 16 ), gain, gain );
            SKP_assert( gain_squared > 0 );
            gain = SKP_Silk_SQRT_APPROX( gain_squared );                  /* Q8   */
            psEncCtrl->Gains_Q16[ k ] = SKP_LSHIFT_SAT32( gain, 8 );        /* Q16  */
        } else {
            gain = SKP_Silk_SQRT_APPROX( gain_squared );                  /* Q0   */
            psEncCtrl->Gains_Q16[ k ] = SKP_LSHIFT_SAT32( gain, 16 );       /* Q16  */
        }
    }

    /* Noise shaping quantization */
    SKP_Silk_gains_quant( psEncCtrl->sCmn.GainsIndices, psEncCtrl->Gains_Q16, 
        &psShapeSt->LastGainIndex, psEnc->sCmn.nFramesInPayloadBuf );
    /* Set quantizer offset for voiced signals. Larger offset when LTP coding gain is low or tilt is high (ie low-pass) */
    if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) {
        if( psEncCtrl->LTPredCodGain_Q7 + SKP_RSHIFT( psEncCtrl->input_tilt_Q15, 8 ) > ( 1 << 7 ) ) {
            psEncCtrl->sCmn.QuantOffsetType = 0;
        } else {
            psEncCtrl->sCmn.QuantOffsetType = 1;
        }
    }

    /* Quantizer boundary adjustment */
    if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) {
        psEncCtrl->Lambda_Q10 = SKP_FIX_CONST( 1.3, 10 )
                  - SKP_SMULWB( SKP_FIX_CONST( 0.5, 18 ), psEnc->speech_activity_Q8       )
                  - SKP_SMULWB( SKP_FIX_CONST( 0.3, 12 ), psEncCtrl->input_quality_Q14    )
                  + SKP_SMULBB( SKP_FIX_CONST( 0.2, 10 ), psEncCtrl->sCmn.QuantOffsetType )
                  - SKP_SMULWB( SKP_FIX_CONST( 0.1, 12 ), psEncCtrl->coding_quality_Q14   );
    } else {
        psEncCtrl->Lambda_Q10 = SKP_FIX_CONST( 1.3, 10 )
                  - SKP_SMULWB( SKP_FIX_CONST( 0.5, 18 ), psEnc->speech_activity_Q8       )
                  - SKP_SMULWB( SKP_FIX_CONST( 0.4, 12 ), psEncCtrl->input_quality_Q14    )
                  + SKP_SMULBB( SKP_FIX_CONST( 0.4, 10 ), psEncCtrl->sCmn.QuantOffsetType )
                  - SKP_SMULWB( SKP_FIX_CONST( 0.1, 12 ), psEncCtrl->coding_quality_Q14   );
    }
    SKP_assert( psEncCtrl->Lambda_Q10 >= 0 );
    SKP_assert( psEncCtrl->Lambda_Q10 < SKP_FIX_CONST( 2, 10 ) );
    
}
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 [ 2 * frame_length + la_shape ]*/
)
{
    SKP_Silk_shape_state_FIX *psShapeSt = &psEnc->sShape;
    SKP_int     k, nSamples, lz, Qnrg, b_Q14, scale = 0, sz;
    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[     SHAPE_LPC_ORDER_MAX + 1 ];
    SKP_int32   refl_coef_Q16[ SHAPE_LPC_ORDER_MAX ];
    SKP_int32   AR_Q24[        SHAPE_LPC_ORDER_MAX ];
    SKP_int16   x_windowed[    SHAPE_LPC_WIN_MAX ];
    const SKP_int16 *x_ptr, *pitch_res_ptr;

    SKP_int32   sqrt_nrg[ NB_SUBFR ], Qnrg_vec[ NB_SUBFR ];

    /* Point to start of first LPC analysis block */
    x_ptr = x + psEnc->sCmn.la_shape - SKP_SMULBB( SHAPE_LPC_WIN_MS, psEnc->sCmn.fs_kHz ) + psEnc->sCmn.frame_length / NB_SUBFR;

    /****************/
    /* 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 ), 3277 );

    /* Reduce SNR_dB if inband FEC used */
    if( psEnc->speech_activity_Q8 > LBRR_SPEECH_ACTIVITY_THRES_Q8 ) {
        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 - ( 18 << 7 ), 4 ) ), 1 );

    /* Reduce coding SNR during low speech activity */
    b_Q8 = ( 1 << 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( -BG_SNR_DECR_dB_Q7 >> ( 4 + 1 ), b_Q8 ),                                            // Q11
        SKP_SMULWB( ( 1 << 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, HARM_SNR_INCR_dB_Q7 << 1, 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( 6 << ( 7 + 2 ), -104856, psEncCtrl->current_SNR_dB_Q7 ),    //-104856_Q18 = -0.4_Q0, Q9
            ( 1 << 14 ) - psEncCtrl->input_quality_Q14 );                           // 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 - ( 5 << 7 ), 6554 ) ), 7 );    // 6554_Q16 = 0.1_Q0

        /* Set quantization offset depending on sparseness measure */
        if( psEncCtrl->sparseness_Q8 > SPARSENESS_THRESHOLD_QNT_OFFSET_Q8 ) {
            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, SPARSE_SNR_INCR_dB_Q7 << 8, psEncCtrl->sparseness_Q8 - ( 1 << 7 ) );
    }

    /*******************************/
    /* Control bandwidth expansion */
    /*******************************/
    delta_Q16  = SKP_SMULWB( ( 1 << 16 ) - SKP_SMULBB( 3, psEncCtrl->coding_quality_Q14 ), LOW_RATE_BANDWIDTH_EXPANSION_DELTA_Q16 );
    BWExp1_Q16 = BANDWIDTH_EXPANSION_Q16 - delta_Q16;
    BWExp2_Q16 = BANDWIDTH_EXPANSION_Q16 + delta_Q16;
    if( psEnc->sCmn.fs_kHz == 24 ) {
        /* Less bandwidth expansion for super wideband */
        BWExp1_Q16 = ( 1 << 16 ) - SKP_SMULWB( SWB_BANDWIDTH_EXPANSION_REDUCTION_Q16, ( 1 << 16 ) - BWExp1_Q16 );
        BWExp2_Q16 = ( 1 << 16 ) - SKP_SMULWB( SWB_BANDWIDTH_EXPANSION_REDUCTION_Q16, ( 1 << 16 ) - BWExp2_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 ) );

    /********************************************/
    /* Compute noise shaping AR coefs and gains */
    /********************************************/
    sz = ( SKP_int )SKP_SMULBB( SHAPE_LPC_WIN_MS, psEnc->sCmn.fs_kHz );
    for( k = 0; k < NB_SUBFR; k++ ) {
        /* Apply window */
        SKP_Silk_apply_sine_window( x_windowed, x_ptr, 0, SHAPE_LPC_WIN_MS * psEnc->sCmn.fs_kHz );

        /* Update pointer: next LPC analysis block */
        x_ptr += psEnc->sCmn.frame_length / NB_SUBFR;

        /* Calculate auto correlation */
        SKP_Silk_autocorr( auto_corr, &scale, x_windowed, sz, 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 ), SHAPE_WHITE_NOISE_FRACTION_Q20 ), 1 ) ); 

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

        /* Convert reflection coefficients to prediction coefficients */
        SKP_Silk_k2a_Q16( AR_Q24, refl_coef_Q16, psEnc->sCmn.shapingLPCOrder );

        /* Bandwidth expansion for synthesis filter shaping */
        SKP_Silk_bwexpander_32( AR_Q24, psEnc->sCmn.shapingLPCOrder, BWExp2_Q16 );

        /* Make sure to fit in Q13 SKP_int16 */
        SKP_Silk_LPC_fit( &psEncCtrl->AR2_Q13[ k * SHAPE_LPC_ORDER_MAX ], AR_Q24, 13, psEnc->sCmn.shapingLPCOrder );

        /* Compute noise shaping filter coefficients */
        SKP_memcpy(
            &psEncCtrl->AR1_Q13[ k * SHAPE_LPC_ORDER_MAX ], 
            &psEncCtrl->AR2_Q13[ k * SHAPE_LPC_ORDER_MAX ], 
            psEnc->sCmn.shapingLPCOrder * sizeof( SKP_int16 ) );

        /* Bandwidth expansion for analysis filter shaping */
        SKP_assert( BWExp1_Q16 <= ( 1 << 16 ) ); // If ever breaking, use LPC_stabilize() in these cases to stay within range
        SKP_Silk_bwexpander( &psEncCtrl->AR1_Q13[ k * SHAPE_LPC_ORDER_MAX ], psEnc->sCmn.shapingLPCOrder, BWExp1_Q16 );

        /* Increase residual energy */
        nrg = SKP_SMLAWB( nrg, SKP_RSHIFT( auto_corr[ 0 ], 8 ), SHAPE_MIN_ENERGY_RATIO_Q24 );

        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

        sqrt_nrg[ k ] = tmp32;
        Qnrg_vec[ k ] = Qnrg;

        psEncCtrl->Gains_Q16[ k ] = SKP_LSHIFT_SAT32( tmp32, 16 - Qnrg );
        /* Ratio of prediction gains, in energy domain */
        SKP_Silk_LPC_inverse_pred_gain_Q13( &pre_nrg_Q30, &psEncCtrl->AR2_Q13[ k * SHAPE_LPC_ORDER_MAX ], psEnc->sCmn.shapingLPCOrder );
        SKP_Silk_LPC_inverse_pred_gain_Q13( &nrg,         &psEncCtrl->AR1_Q13[ k * SHAPE_LPC_ORDER_MAX ], psEnc->sCmn.shapingLPCOrder );

        lz = SKP_min_32( SKP_Silk_CLZ32( pre_nrg_Q30 ) - 1, 19 );
        pre_nrg_Q30 = SKP_DIV32( SKP_LSHIFT( pre_nrg_Q30, lz ), SKP_RSHIFT( nrg, 20 - lz ) + 1 ); // Q20
        pre_nrg_Q30 = SKP_RSHIFT( SKP_LSHIFT_SAT32( pre_nrg_Q30, 9 ), 1 );  /* Q28 */
        psEncCtrl->GainsPre_Q14[ k ] = ( SKP_int )SKP_Silk_SQRT_APPROX( pre_nrg_Q30 );
    }
/* Control encoder SNR */
SKP_int SKP_Silk_control_encoder_FIX( 
    SKP_Silk_encoder_state_FIX  *psEnc,             /* I/O  Pointer to Silk encoder state                   */
    const SKP_int32             API_fs_Hz,          /* I    External (API) sampling rate (Hz)               */
    const SKP_int               max_internal_fs_kHz,/* I    Maximum internal sampling rate (kHz)            */
    const SKP_int               PacketSize_ms,      /* I    Packet length (ms)                              */
    SKP_int32                   TargetRate_bps,     /* I    Target max bitrate (bps) (used if SNR_dB == 0)  */
    const SKP_int               PacketLoss_perc,    /* I    Packet loss rate (in percent)                   */
    const SKP_int               INBandFEC_enabled,  /* I    Enable (1) / disable (0) inband FEC             */
    const SKP_int               DTX_enabled,        /* I    Enable / disable DTX                            */
    const SKP_int               InputFramesize_ms,  /* I    Inputframe in ms                                */
    const SKP_int               Complexity          /* I    Complexity (0->low; 1->medium; 2->high)         */
)
{
    SKP_int32 LBRRRate_thres_bps;
    SKP_int   k, fs_kHz, ret = 0;
    SKP_int32 frac_Q6;
    const SKP_int32 *rateTable;

    /* State machine for the SWB/WB switching */
    fs_kHz = psEnc->sCmn.fs_kHz;
    
    /* Only switch during low speech activity, when no frames are sitting in the payload buffer */
    if( API_fs_Hz == 8000 || fs_kHz == 0 || API_fs_Hz < SKP_SMULBB( fs_kHz, 1000 ) || fs_kHz > max_internal_fs_kHz ) {
        /* Switching is not possible, encoder just initialized, internal mode higher than external, */
        /* or internal mode higher than maximum allowed internal mode                               */
        fs_kHz = SKP_min( SKP_DIV32_16( API_fs_Hz, 1000 ), max_internal_fs_kHz );
    } else {
        /* Accumulate the difference between the target rate and limit for switching down */
        psEnc->sCmn.bitrateDiff += SKP_MUL( InputFramesize_ms, TargetRate_bps - psEnc->sCmn.bitrate_threshold_down );
        psEnc->sCmn.bitrateDiff  = SKP_min( psEnc->sCmn.bitrateDiff, 0 );

        if( psEnc->speech_activity_Q8 < 128 && psEnc->sCmn.nFramesInPayloadBuf == 0 ) { /* Low speech activity and payload buffer empty */
            /* Check if we should switch down */
#if SWITCH_TRANSITION_FILTERING 
            if( ( psEnc->sCmn.sLP.transition_frame_no == 0 ) &&                         /* Transition phase not active */
                ( psEnc->sCmn.bitrateDiff <= -ACCUM_BITS_DIFF_THRESHOLD ||              /* Bitrate threshold is met */
                ( psEnc->sCmn.sSWBdetect.WB_detected * psEnc->sCmn.fs_kHz == 24 ) ) ) { /* Forced down-switching due to WB input */
                psEnc->sCmn.sLP.transition_frame_no = 1;                                /* Begin transition phase */
                psEnc->sCmn.sLP.mode                = 0;                                /* Switch down */
            } else if( 
                ( psEnc->sCmn.sLP.transition_frame_no >= TRANSITION_FRAMES_DOWN ) &&    /* Transition phase complete */
                ( psEnc->sCmn.sLP.mode == 0 ) ) {                                       /* Ready to switch down */
                psEnc->sCmn.sLP.transition_frame_no = 0;                                /* Ready for new transition phase */
#else
            if( psEnc->sCmn.bitrateDiff <= -ACCUM_BITS_DIFF_THRESHOLD ) {               /* Bitrate threshold is met */ 
#endif            
                psEnc->sCmn.bitrateDiff = 0;

                /* Switch to a lower sample frequency */
                if( psEnc->sCmn.fs_kHz == 24 ) {
                    fs_kHz = 16;
                } else if( psEnc->sCmn.fs_kHz == 16 ) {
                    fs_kHz = 12;
                } else {
                    SKP_assert( psEnc->sCmn.fs_kHz == 12 );
                    fs_kHz = 8;
                }
            }

            /* Check if we should switch up */
            if( ( ( SKP_SMULBB( psEnc->sCmn.fs_kHz, 1000 ) < API_fs_Hz ) &&
                ( TargetRate_bps >= psEnc->sCmn.bitrate_threshold_up ) && 
                ( psEnc->sCmn.sSWBdetect.WB_detected * psEnc->sCmn.fs_kHz != 16 ) ) && 
                ( ( psEnc->sCmn.fs_kHz == 16 ) && ( max_internal_fs_kHz >= 24 ) || 
                  ( psEnc->sCmn.fs_kHz == 12 ) && ( max_internal_fs_kHz >= 16 ) ||
                  ( psEnc->sCmn.fs_kHz ==  8 ) && ( max_internal_fs_kHz >= 12 ) ) 
#if SWITCH_TRANSITION_FILTERING
                  && ( psEnc->sCmn.sLP.transition_frame_no == 0 ) ) { /* No transition phase running, ready to switch */
                    psEnc->sCmn.sLP.mode = 1; /* Switch up */
#else
                ) {
#endif
                psEnc->sCmn.bitrateDiff = 0;

                /* Switch to a higher sample frequency */
                if( psEnc->sCmn.fs_kHz == 8 ) {
                    fs_kHz = 12;
                } else if( psEnc->sCmn.fs_kHz == 12 ) {
                    fs_kHz = 16;
                } else {
                    SKP_assert( psEnc->sCmn.fs_kHz == 16 );
                    fs_kHz = 24;
                } 
            }
        }
    }
/* Encode side-information parameters to payload */
void silk_encode_indices(
    silk_encoder_state          *psEncC,            /* I/O  Encoder state                               */
    ec_enc                      *psRangeEnc,        /* I/O  Compressor data structure                   */
    opus_int                     FrameIndex,         /* I    Frame number                                */
    opus_int                     encode_LBRR         /* I    Flag indicating LBRR data is being encoded  */
)
{
    opus_int   i, k, condCoding, typeOffset;
    opus_int   encode_absolute_lagIndex, delta_lagIndex;
    opus_int16 ec_ix[ MAX_LPC_ORDER ];
    opus_uint8 pred_Q8[ MAX_LPC_ORDER ];
    const SideInfoIndices *psIndices;
#if SAVE_ALL_INTERNAL_DATA
    opus_int nBytes_lagIndex, nBytes_contourIndex, nBytes_LTP;
    opus_int nBytes_after, nBytes_before;
#endif

    /* Use conditional coding if previous frame available */
    if( FrameIndex > 0 && ( encode_LBRR == 0 || psEncC->LBRR_flags[ FrameIndex - 1 ] == 1 ) ) {
        condCoding = 1;
    } else {
        condCoding = 0;
    }

    if( encode_LBRR ) {
         psIndices = &psEncC->indices_LBRR[ FrameIndex ];
    } else {
         psIndices = &psEncC->indices;
    }

    /*******************************************/
    /* Encode signal type and quantizer offset */
    /*******************************************/
    typeOffset = 2 * psIndices->signalType + psIndices->quantOffsetType;
    SKP_assert( typeOffset >= 0 && typeOffset < 6 );
    SKP_assert( encode_LBRR == 0 || typeOffset >= 2 );
    if( encode_LBRR || typeOffset >= 2 ) {
        ec_enc_icdf( psRangeEnc, typeOffset - 2, silk_type_offset_VAD_iCDF, 8 );
    } else {
        ec_enc_icdf( psRangeEnc, typeOffset, silk_type_offset_no_VAD_iCDF, 8 );
    }

    /****************/
    /* Encode gains */
    /****************/
#ifdef SAVE_ALL_INTERNAL_DATA
    nBytes_before = SKP_RSHIFT( ec_tell( psRangeEnc ) + 7, 3 );
#endif
    /* first subframe */
    if( condCoding ) {
        /* conditional coding */
        SKP_assert( psIndices->GainsIndices[ 0 ] >= 0 && psIndices->GainsIndices[ 0 ] < MAX_DELTA_GAIN_QUANT - MIN_DELTA_GAIN_QUANT + 1 );
        ec_enc_icdf( psRangeEnc, psIndices->GainsIndices[ 0 ], silk_delta_gain_iCDF, 8 );
    } else {
        /* independent coding, in two stages: MSB bits followed by 3 LSBs */
        SKP_assert( psIndices->GainsIndices[ 0 ] >= 0 && psIndices->GainsIndices[ 0 ] < N_LEVELS_QGAIN );
        ec_enc_icdf( psRangeEnc, SKP_RSHIFT( psIndices->GainsIndices[ 0 ], 3 ), silk_gain_iCDF[ psIndices->signalType ], 8 );
        ec_enc_icdf( psRangeEnc, psIndices->GainsIndices[ 0 ] & 7, silk_uniform8_iCDF, 8 );
    }

    /* remaining subframes */
    for( i = 1; i < psEncC->nb_subfr; i++ ) {
        SKP_assert( psIndices->GainsIndices[ i ] >= 0 && psIndices->GainsIndices[ i ] < MAX_DELTA_GAIN_QUANT - MIN_DELTA_GAIN_QUANT + 1 );
        ec_enc_icdf( psRangeEnc, psIndices->GainsIndices[ i ], silk_delta_gain_iCDF, 8 );
    }

#ifdef SAVE_ALL_INTERNAL_DATA
    nBytes_after = SKP_RSHIFT( ec_tell( psRangeEnc ) + 7, 3 );
    nBytes_after -= nBytes_before; // bytes just added
    DEBUG_STORE_DATA( nBytes_gains.dat, &nBytes_after, sizeof( opus_int ) );
#endif

    /****************/
    /* Encode NLSFs */
    /****************/
#ifdef SAVE_ALL_INTERNAL_DATA
    nBytes_before = SKP_RSHIFT( ec_tell( psRangeEnc ) + 7, 3 );
#endif
    ec_enc_icdf( psRangeEnc, psIndices->NLSFIndices[ 0 ], &psEncC->psNLSF_CB->CB1_iCDF[ ( psIndices->signalType >> 1 ) * psEncC->psNLSF_CB->nVectors ], 8 );
    silk_NLSF_unpack( ec_ix, pred_Q8, psEncC->psNLSF_CB, psIndices->NLSFIndices[ 0 ] );
    SKP_assert( psEncC->psNLSF_CB->order == psEncC->predictLPCOrder );
    for( i = 0; i < psEncC->psNLSF_CB->order; i++ ) {
        if( psIndices->NLSFIndices[ i+1 ] >= NLSF_QUANT_MAX_AMPLITUDE ) {
            ec_enc_icdf( psRangeEnc, 2 * NLSF_QUANT_MAX_AMPLITUDE, &psEncC->psNLSF_CB->ec_iCDF[ ec_ix[ i ] ], 8 );
            ec_enc_icdf( psRangeEnc, psIndices->NLSFIndices[ i+1 ] - NLSF_QUANT_MAX_AMPLITUDE, silk_NLSF_EXT_iCDF, 8 );
        } else if( psIndices->NLSFIndices[ i+1 ] <= -NLSF_QUANT_MAX_AMPLITUDE ) {
            ec_enc_icdf( psRangeEnc, 0, &psEncC->psNLSF_CB->ec_iCDF[ ec_ix[ i ] ], 8 );
            ec_enc_icdf( psRangeEnc, -psIndices->NLSFIndices[ i+1 ] - NLSF_QUANT_MAX_AMPLITUDE, silk_NLSF_EXT_iCDF, 8 );
        } else {
            ec_enc_icdf( psRangeEnc, psIndices->NLSFIndices[ i+1 ] + NLSF_QUANT_MAX_AMPLITUDE, &psEncC->psNLSF_CB->ec_iCDF[ ec_ix[ i ] ], 8 );
        }
    }

    /* Encode NLSF interpolation factor */
    if( psEncC->nb_subfr == MAX_NB_SUBFR ) {
        SKP_assert( psEncC->useInterpolatedNLSFs == 1 || psIndices->NLSFInterpCoef_Q2 == ( 1 << 2 ) );
        SKP_assert( psIndices->NLSFInterpCoef_Q2 >= 0 && psIndices->NLSFInterpCoef_Q2 < 5 );
        ec_enc_icdf( psRangeEnc, psIndices->NLSFInterpCoef_Q2, silk_NLSF_interpolation_factor_iCDF, 8 );
    }

#ifdef SAVE_ALL_INTERNAL_DATA
    DEBUG_STORE_DATA( lsf_interpol.dat, &psIndices->NLSFInterpCoef_Q2, sizeof(int) );
    nBytes_after = SKP_RSHIFT( ec_tell( psRangeEnc ) + 7, 3 );
    nBytes_after -= nBytes_before; // bytes just added
    DEBUG_STORE_DATA( nBytes_LSF.dat, &nBytes_after, sizeof( opus_int ) );
#endif

    if( psIndices->signalType == TYPE_VOICED ) 
    {
        /*********************/
        /* Encode pitch lags */
        /*********************/
#ifdef SAVE_ALL_INTERNAL_DATA
        nBytes_before = SKP_RSHIFT( ec_tell( psRangeEnc ) + 7, 3 );
#endif
        /* lag index */
        encode_absolute_lagIndex = 1;
        if( condCoding && psEncC->ec_prevSignalType == TYPE_VOICED ) {
            /* Delta Encoding */
            delta_lagIndex = psIndices->lagIndex - psEncC->ec_prevLagIndex;
            if( delta_lagIndex < -8 || delta_lagIndex > 11 ) {
                delta_lagIndex = 0;
            } else {
                delta_lagIndex = delta_lagIndex + 9;
                encode_absolute_lagIndex = 0; /* Only use delta */
            }
            SKP_assert( delta_lagIndex >= 0 && delta_lagIndex < 21 );
            ec_enc_icdf( psRangeEnc, delta_lagIndex, silk_pitch_delta_iCDF, 8 );
        }
        if( encode_absolute_lagIndex ) {
            /* Absolute encoding */
            opus_int32 pitch_high_bits, pitch_low_bits;
            pitch_high_bits = SKP_DIV32_16( psIndices->lagIndex, SKP_RSHIFT( psEncC->fs_kHz, 1 ) );
            pitch_low_bits = psIndices->lagIndex - SKP_SMULBB( pitch_high_bits, SKP_RSHIFT( psEncC->fs_kHz, 1 ) );
            SKP_assert( pitch_low_bits < psEncC->fs_kHz / 2 );
            SKP_assert( pitch_high_bits < 32 );
            ec_enc_icdf( psRangeEnc, pitch_high_bits, silk_pitch_lag_iCDF, 8 );
            ec_enc_icdf( psRangeEnc, pitch_low_bits, psEncC->pitch_lag_low_bits_iCDF, 8 );
        }
        psEncC->ec_prevLagIndex = psIndices->lagIndex;

#ifdef SAVE_ALL_INTERNAL_DATA
        nBytes_after = SKP_RSHIFT( ec_tell( psRangeEnc ) + 7, 3 );
        nBytes_lagIndex = nBytes_after - nBytes_before; // bytes just added
#endif

#ifdef SAVE_ALL_INTERNAL_DATA
        nBytes_before = SKP_RSHIFT( ec_tell( psRangeEnc ) + 7, 3 );
#endif
        /* Countour index */
        SKP_assert(   psIndices->contourIndex  >= 0 );
        SKP_assert( ( psIndices->contourIndex < 34 && psEncC->fs_kHz  > 8 && psEncC->nb_subfr == 4 ) ||
                    ( psIndices->contourIndex < 11 && psEncC->fs_kHz == 8 && psEncC->nb_subfr == 4 ) ||
                    ( psIndices->contourIndex < 12 && psEncC->fs_kHz  > 8 && psEncC->nb_subfr == 2 ) ||
                    ( psIndices->contourIndex <  3 && psEncC->fs_kHz == 8 && psEncC->nb_subfr == 2 ) );
        ec_enc_icdf( psRangeEnc, psIndices->contourIndex, psEncC->pitch_contour_iCDF, 8 );
#ifdef SAVE_ALL_INTERNAL_DATA
        nBytes_after = SKP_RSHIFT( ec_tell( psRangeEnc ) + 7, 3 );
        nBytes_contourIndex = nBytes_after - nBytes_before; // bytes just added
#endif

        /********************/
        /* Encode LTP gains */
        /********************/
#ifdef SAVE_ALL_INTERNAL_DATA
        nBytes_before = SKP_RSHIFT( ec_tell( psRangeEnc ) + 7, 3 );
#endif

        /* PERIndex value */
        SKP_assert( psIndices->PERIndex >= 0 && psIndices->PERIndex < 3 );
        ec_enc_icdf( psRangeEnc, psIndices->PERIndex, silk_LTP_per_index_iCDF, 8 );

        /* Codebook Indices */
        for( k = 0; k < psEncC->nb_subfr; k++ ) {
            SKP_assert( psIndices->LTPIndex[ k ] >= 0 && psIndices->LTPIndex[ k ] < ( 8 << psIndices->PERIndex ) );
            ec_enc_icdf( psRangeEnc, psIndices->LTPIndex[ k ], silk_LTP_gain_iCDF_ptrs[ psIndices->PERIndex ], 8 );
        }

        /**********************/
        /* Encode LTP scaling */
        /**********************/
        if( !condCoding ) {
            SKP_assert( psIndices->LTP_scaleIndex >= 0 && psIndices->LTP_scaleIndex < 3 );
            ec_enc_icdf( psRangeEnc, psIndices->LTP_scaleIndex, silk_LTPscale_iCDF, 8 );
        }
        SKP_assert( !condCoding || psIndices->LTP_scaleIndex == 0 );

#ifdef SAVE_ALL_INTERNAL_DATA
        nBytes_after = SKP_RSHIFT( ec_tell( psRangeEnc ) + 7, 3 );
        nBytes_LTP = nBytes_after - nBytes_before; // bytes just added
#endif
    }
#ifdef SAVE_ALL_INTERNAL_DATA
    else { 
        // Unvoiced speech
        nBytes_lagIndex     = 0;
        nBytes_contourIndex = 0;
        nBytes_LTP          = 0;
    }
    DEBUG_STORE_DATA( nBytes_lagIndex.dat,      &nBytes_lagIndex,       sizeof( opus_int ) );
    DEBUG_STORE_DATA( nBytes_contourIndex.dat,  &nBytes_contourIndex,   sizeof( opus_int ) );
    DEBUG_STORE_DATA( nBytes_LTP.dat,           &nBytes_LTP,            sizeof( opus_int ) );
#endif

    psEncC->ec_prevSignalType = psIndices->signalType;

#ifdef SAVE_ALL_INTERNAL_DATA
    nBytes_before = SKP_RSHIFT( ec_tell( psRangeEnc ) + 7, 3 );
#endif

    /***************/
    /* Encode seed */
    /***************/
    SKP_assert( psIndices->Seed >= 0 && psIndices->Seed < 4 );
    ec_enc_icdf( psRangeEnc, psIndices->Seed, silk_uniform4_iCDF, 8 );
}
/* Control internal sampling rate */
SKP_int SKP_Silk_control_audio_bandwidth(
    SKP_Silk_encoder_state      *psEncC,            /* I/O  Pointer to Silk encoder state               */
    SKP_int32                   TargetRate_bps      /* I    Target max bitrate (bps)                    */
)
{
    SKP_int fs_kHz;

    fs_kHz = psEncC->fs_kHz;

    /* Reduce bitrate for 10 ms modes in these calculations */
    if( psEncC->nb_subfr == 2 ) {
        TargetRate_bps -= REDUCE_BITRATE_10_MS_BPS;
    }

    if( fs_kHz == 0 ) {
        /* Encoder has just been initialized */
        if( TargetRate_bps >= WB2MB_BITRATE_BPS ) {
            fs_kHz = 16;
        } else if( TargetRate_bps >= MB2NB_BITRATE_BPS ) {
            fs_kHz = 12;
        } else {
            fs_kHz = 8;
        }
        /* Make sure internal rate is not higher than external rate or maximum allowed, or lower than minimum allowed */
        fs_kHz = SKP_min( fs_kHz, SKP_DIV32_16( psEncC->API_fs_Hz, 1000 ) );
        fs_kHz = SKP_min( fs_kHz, psEncC->maxInternal_fs_kHz );
        fs_kHz = SKP_max( fs_kHz, psEncC->minInternal_fs_kHz );
    } else if( SKP_SMULBB( fs_kHz, 1000 ) > psEncC->API_fs_Hz || fs_kHz > psEncC->maxInternal_fs_kHz || fs_kHz < psEncC->minInternal_fs_kHz ) {
        /* Make sure internal rate is not higher than external rate or maximum allowed, or lower than minimum allowed */
        fs_kHz = SKP_DIV32_16( psEncC->API_fs_Hz, 1000 );
        fs_kHz = SKP_min( fs_kHz, psEncC->maxInternal_fs_kHz );
        fs_kHz = SKP_max( fs_kHz, psEncC->minInternal_fs_kHz );
    } else {
        /* State machine for the internal sampling rate switching */
        if( psEncC->API_fs_Hz > 8000 && psEncC->prevSignalType == TYPE_NO_VOICE_ACTIVITY ) { /* Low speech activity */
            /* Check if we should switch down */
            if( ( psEncC->fs_kHz == 12 && TargetRate_bps < MB2NB_BITRATE_BPS && psEncC->minInternal_fs_kHz <=  8 ) ||
                ( psEncC->fs_kHz == 16 && TargetRate_bps < WB2MB_BITRATE_BPS && psEncC->minInternal_fs_kHz <= 12 ) ) 
            {
                /* Switch down */
                if( SWITCH_TRANSITION_FILTERING && psEncC->sLP.mode == 0 ) {
                    /* New transition */
                    psEncC->sLP.transition_frame_no = TRANSITION_FRAMES;

                    /* Reset transition filter state */
                    SKP_memset( psEncC->sLP.In_LP_State, 0, sizeof( psEncC->sLP.In_LP_State ) );
                } 
                if( psEncC->sLP.transition_frame_no <= 0 ) {
                    /* Stop transition phase */
                    psEncC->sLP.mode = 0;

                    /* Switch to a lower sample frequency */
                    fs_kHz = psEncC->fs_kHz == 16 ? 12 : 8;
                } else {
                    /* Direction: down (at double speed) */
                    psEncC->sLP.mode = -2;
                } 
            } 
            else
            if( ( psEncC->fs_kHz ==  8 && TargetRate_bps > NB2MB_BITRATE_BPS && psEncC->maxInternal_fs_kHz >= 12 && psEncC->API_fs_Hz >= 12000 ) ||
                ( psEncC->fs_kHz == 12 && TargetRate_bps > MB2WB_BITRATE_BPS && psEncC->maxInternal_fs_kHz >= 16 && psEncC->API_fs_Hz >= 16000 ) ) 
            {
                /* Switch up */
                if( SWITCH_TRANSITION_FILTERING && psEncC->sLP.mode == 0 ) {
                    /* Switch to a higher sample frequency */
                    fs_kHz = psEncC->fs_kHz == 8 ? 12 : 16;

                    /* New transition */
                    psEncC->sLP.transition_frame_no = 0;
                } 
                if( psEncC->sLP.transition_frame_no >= TRANSITION_FRAMES ) {
                    /* Stop transition phase */
                    psEncC->sLP.mode = 0;
                } else {
                    /* Direction: up */
                    psEncC->sLP.mode = 1;
                }
            }
        }
    }

#ifdef FORCE_INTERNAL_FS_KHZ
    fs_kHz = FORCE_INTERNAL_FS_KHZ;
#endif

    return fs_kHz;
}
void SKP_Silk_NLSF_MSVQ_encode_FIX(
    SKP_int                   *NLSFIndices,           /* O    Codebook path vector [ CB_STAGES ]      */
    SKP_int                   *pNLSF_Q15,             /* I/O  Quantized NLSF vector [ LPC_ORDER ]     */
    const SKP_Silk_NLSF_CB_struct   *psNLSF_CB,             /* I    Codebook object                         */
    const SKP_int                   *pNLSF_q_Q15_prev,      /* I    Prev. quantized NLSF vector [LPC_ORDER] */
    const SKP_int                   *pW_Q6,                 /* I    NLSF weight vector [ LPC_ORDER ]        */
    const SKP_int                   NLSF_mu_Q15,            /* I    Rate weight for the RD optimization     */
    const SKP_int                   NLSF_mu_fluc_red_Q16,   /* I    Fluctuation reduction error weight      */
    const SKP_int                   NLSF_MSVQ_Survivors,    /* I    Max survivors from each stage           */
    const SKP_int                   LPC_order,              /* I    LPC order                               */
    const SKP_int                   deactivate_fluc_red     /* I    Deactivate fluctuation reduction        */
)
{
    SKP_int     i, s, k, cur_survivors = 0, prev_survivors, input_index, cb_index, bestIndex;
    SKP_int32   rateDistThreshold_Q18;
    SKP_int     pNLSF_in_Q15[ MAX_LPC_ORDER ];
#if( NLSF_MSVQ_FLUCTUATION_REDUCTION == 1 )
    SKP_int32   se_Q15, wsse_Q20, bestRateDist_Q20;
#endif

#if( LOW_COMPLEXITY_ONLY == 1 )
    SKP_int32   pRateDist_Q18[  NLSF_MSVQ_TREE_SEARCH_MAX_VECTORS_EVALUATED_LC_MODE ];
    SKP_int32   pRate_Q5[       MAX_NLSF_MSVQ_SURVIVORS_LC_MODE ];
    SKP_int32   pRate_new_Q5[   MAX_NLSF_MSVQ_SURVIVORS_LC_MODE ];
    SKP_int     pTempIndices[   MAX_NLSF_MSVQ_SURVIVORS_LC_MODE ];
    SKP_int     pPath[          MAX_NLSF_MSVQ_SURVIVORS_LC_MODE * NLSF_MSVQ_MAX_CB_STAGES ];
    SKP_int     pPath_new[      MAX_NLSF_MSVQ_SURVIVORS_LC_MODE * NLSF_MSVQ_MAX_CB_STAGES ];
    SKP_int     pRes_Q15[       MAX_NLSF_MSVQ_SURVIVORS_LC_MODE * MAX_LPC_ORDER ];
    SKP_int     pRes_new_Q15[   MAX_NLSF_MSVQ_SURVIVORS_LC_MODE * MAX_LPC_ORDER ];
#else
    SKP_int32   pRateDist_Q18[  NLSF_MSVQ_TREE_SEARCH_MAX_VECTORS_EVALUATED ];
    SKP_int32   pRate_Q5[       MAX_NLSF_MSVQ_SURVIVORS ];
    SKP_int32   pRate_new_Q5[   MAX_NLSF_MSVQ_SURVIVORS ];
    SKP_int     pTempIndices[   MAX_NLSF_MSVQ_SURVIVORS ];
    SKP_int     pPath[          MAX_NLSF_MSVQ_SURVIVORS * NLSF_MSVQ_MAX_CB_STAGES ];
    SKP_int     pPath_new[      MAX_NLSF_MSVQ_SURVIVORS * NLSF_MSVQ_MAX_CB_STAGES ];
    SKP_int     pRes_Q15[       MAX_NLSF_MSVQ_SURVIVORS * MAX_LPC_ORDER ];
    SKP_int     pRes_new_Q15[   MAX_NLSF_MSVQ_SURVIVORS * MAX_LPC_ORDER ];
#endif

    const SKP_int   *pConstInt;
    SKP_int   *pInt;
    const SKP_int16 *pCB_element;
    const SKP_Silk_NLSF_CBS *pCurrentCBStage;

    SKP_assert( NLSF_MSVQ_Survivors <= MAX_NLSF_MSVQ_SURVIVORS );
    SKP_assert( ( LOW_COMPLEXITY_ONLY == 0 ) || ( NLSF_MSVQ_Survivors <= MAX_NLSF_MSVQ_SURVIVORS_LC_MODE ) );



    /* Copy the input vector */
    SKP_memcpy( pNLSF_in_Q15, pNLSF_Q15, LPC_order * sizeof( SKP_int ) );

    /****************************************************/
    /* Tree search for the multi-stage vector quantizer */
    /****************************************************/

    /* Clear accumulated rates */
    SKP_memset( pRate_Q5, 0, NLSF_MSVQ_Survivors * sizeof( SKP_int32 ) );

    /* Copy NLSFs into residual signal vector */
    for( i = 0; i < LPC_order; i++ ) {
        pRes_Q15[ i ] = pNLSF_Q15[ i ];
    }

    /* Set first stage values */
    prev_survivors = 1;

    /* Loop over all stages */
    for( s = 0; s < psNLSF_CB->nStages; s++ ) {

        /* Set a pointer to the current stage codebook */
        pCurrentCBStage = &psNLSF_CB->CBStages[ s ];

        /* Calculate the number of survivors in the current stage */
        cur_survivors = SKP_min_32( NLSF_MSVQ_Survivors, SKP_SMULBB( prev_survivors, pCurrentCBStage->nVectors ) );

#if( NLSF_MSVQ_FLUCTUATION_REDUCTION == 0 )
        /* Find a single best survivor in the last stage, if we */
        /* do not need candidates for fluctuation reduction     */
        if( s == psNLSF_CB->nStages - 1 ) {
            cur_survivors = 1;
        }
#endif

        /* Nearest neighbor clustering for multiple input data vectors */
        SKP_Silk_NLSF_VQ_rate_distortion_FIX( pRateDist_Q18, pCurrentCBStage, pRes_Q15, pW_Q6,
                                              pRate_Q5, NLSF_mu_Q15, prev_survivors, LPC_order );

        /* Sort the rate-distortion errors */
        SKP_Silk_insertion_sort_increasing( pRateDist_Q18, pTempIndices,
                                            prev_survivors * pCurrentCBStage->nVectors, cur_survivors );

        /* Discard survivors with rate-distortion values too far above the best one */
        if( pRateDist_Q18[ 0 ] < SKP_int32_MAX / NLSF_MSVQ_SURV_MAX_REL_RD ) {
            rateDistThreshold_Q18 = SKP_MUL( NLSF_MSVQ_SURV_MAX_REL_RD, pRateDist_Q18[ 0 ] );
            while( pRateDist_Q18[ cur_survivors - 1 ] > rateDistThreshold_Q18 && cur_survivors > 1 ) {
                cur_survivors--;
            }
        }
        /* Update accumulated codebook contributions for the 'cur_survivors' best codebook indices */
        for( k = 0; k < cur_survivors; k++ ) {
            if( s > 0 ) {
                /* Find the indices of the input and the codebook vector */
                if( pCurrentCBStage->nVectors == 8 ) {
                    input_index = SKP_RSHIFT( pTempIndices[ k ], 3 );
                    cb_index    = pTempIndices[ k ] & 7;
                } else {
                    input_index = SKP_DIV32_16( pTempIndices[ k ], pCurrentCBStage->nVectors );
                    cb_index    = pTempIndices[ k ] - SKP_SMULBB( input_index, pCurrentCBStage->nVectors );
                }
            } else {
                /* Find the indices of the input and the codebook vector */
                input_index = 0;
                cb_index    = pTempIndices[ k ];
            }

            /* Subtract new contribution from the previous residual vector for each of 'cur_survivors' */
            pConstInt   = &pRes_Q15[ SKP_SMULBB( input_index, LPC_order ) ];
            pCB_element = &pCurrentCBStage->CB_NLSF_Q15[ SKP_SMULBB( cb_index, LPC_order ) ];
            pInt        = &pRes_new_Q15[ SKP_SMULBB( k, LPC_order ) ];
            for( i = 0; i < LPC_order; i++ ) {
                pInt[ i ] = pConstInt[ i ] - ( SKP_int )pCB_element[ i ];
            }

            /* Update accumulated rate for stage 1 to the current */
            pRate_new_Q5[ k ] = pRate_Q5[ input_index ] + pCurrentCBStage->Rates_Q5[ cb_index ];

            /* Copy paths from previous matrix, starting with the best path */
            pConstInt = &pPath[ SKP_SMULBB( input_index, psNLSF_CB->nStages ) ];
            pInt      = &pPath_new[ SKP_SMULBB( k, psNLSF_CB->nStages ) ];
            for( i = 0; i < s; i++ ) {
                pInt[ i ] = pConstInt[ i ];
            }
            /* Write the current stage indices for the 'cur_survivors' to the best path matrix */
            pInt[ s ] = cb_index;
        }

        if( s < psNLSF_CB->nStages - 1 ) {
            /* Copy NLSF residual matrix for next stage */
            SKP_memcpy( pRes_Q15, pRes_new_Q15, SKP_SMULBB( cur_survivors, LPC_order ) * sizeof( SKP_int ) );

            /* Copy rate vector for next stage */
            SKP_memcpy( pRate_Q5, pRate_new_Q5, cur_survivors * sizeof( SKP_int32 ) );

            /* Copy best path matrix for next stage */
            SKP_memcpy( pPath, pPath_new, SKP_SMULBB( cur_survivors, psNLSF_CB->nStages ) * sizeof( SKP_int ) );
        }

        prev_survivors = cur_survivors;
    }

    /* (Preliminary) index of the best survivor, later to be decoded */
    bestIndex = 0;

#if( NLSF_MSVQ_FLUCTUATION_REDUCTION == 1 )
    /******************************/
    /* NLSF fluctuation reduction */
    /******************************/
    if( deactivate_fluc_red != 1 ) {

        /* Search among all survivors, now taking also weighted fluctuation errors into account */
        bestRateDist_Q20 = SKP_int32_MAX;
        for( s = 0; s < cur_survivors; s++ ) {
            /* Decode survivor to compare with previous quantized NLSF vector */
            SKP_Silk_NLSF_MSVQ_decode( pNLSF_Q15, psNLSF_CB, &pPath_new[ SKP_SMULBB( s, psNLSF_CB->nStages ) ], LPC_order );

            /* Compare decoded NLSF vector with the previously quantized vector */
            wsse_Q20 = 0;
            for( i = 0; i < LPC_order; i += 2 ) {
                /* Compute weighted squared quantization error for index i */
                se_Q15 = pNLSF_Q15[ i ] - pNLSF_q_Q15_prev[ i ]; // range: [ -32767 : 32767 ]
                wsse_Q20 = SKP_SMLAWB( wsse_Q20, SKP_SMULBB( se_Q15, se_Q15 ), pW_Q6[ i ] );

                /* Compute weighted squared quantization error for index i + 1 */
                se_Q15 = pNLSF_Q15[ i + 1 ] - pNLSF_q_Q15_prev[ i + 1 ]; // range: [ -32767 : 32767 ]
                wsse_Q20 = SKP_SMLAWB( wsse_Q20, SKP_SMULBB( se_Q15, se_Q15 ), pW_Q6[ i + 1 ] );
            }
            SKP_assert( wsse_Q20 >= 0 );

            /* Add the fluctuation reduction penalty to the rate distortion error */
            wsse_Q20 = SKP_ADD_POS_SAT32( pRateDist_Q18[ s ], SKP_SMULWB( wsse_Q20, NLSF_mu_fluc_red_Q16 ) );

            /* Keep index of best survivor */
            if( wsse_Q20 < bestRateDist_Q20 ) {
                bestRateDist_Q20 = wsse_Q20;
                bestIndex = s;
            }
        }
    }
#endif

    /* Copy best path to output argument */
    SKP_memcpy( NLSFIndices, &pPath_new[ SKP_SMULBB( bestIndex, psNLSF_CB->nStages ) ], psNLSF_CB->nStages * sizeof( SKP_int ) );

    /* Decode and stabilize the best survivor */
    SKP_Silk_NLSF_MSVQ_decode( pNLSF_Q15, psNLSF_CB, NLSFIndices, LPC_order );

}
Example #24
0
SKP_int SKP_Silk_SDK_Encode( 
    void                                *encState,      /* I/O: State                                           */
    SKP_Silk_EncodeControlStruct        *encControl,    /* I:   Control structure                               */
    const SKP_int16                     *samplesIn,     /* I:   Speech sample input vector                      */
    SKP_int                             nSamplesIn,     /* I:   Number of samples in input vector               */
    ec_enc                              *psRangeEnc,    /* I/O  Compressor data structure                       */
    SKP_int32                           *nBytesOut,     /* I/O: Number of bytes in payload (input: Max bytes)   */
    const SKP_int                       prefillFlag     /* I:   Flag to indicate prefilling buffers no coding   */
)
{
    SKP_int   tmp_payloadSize_ms, tmp_complexity, ret = 0;
    SKP_int   nSamplesToBuffer, nBlocksOf10ms, nSamplesFromInput = 0;
    SKP_Silk_encoder_state_Fxx *psEnc = ( SKP_Silk_encoder_state_Fxx* )encState;

    ret = process_enc_control_struct( psEnc, encControl );

    nBlocksOf10ms = SKP_DIV32( 100 * nSamplesIn, psEnc->sCmn.API_fs_Hz );
    if( prefillFlag ) {
        /* Only accept input length of 10 ms */
        if( nBlocksOf10ms != 1 ) {
            ret = SKP_SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES;
            SKP_assert( 0 );
            return( ret );
        }
        /* Reset Encoder */
        if( ret = SKP_Silk_init_encoder_Fxx( psEnc ) ) {
            SKP_assert( 0 );
        }
        tmp_payloadSize_ms = encControl->payloadSize_ms;
        encControl->payloadSize_ms = 10;
        tmp_complexity = encControl->complexity;
        encControl->complexity = 0;
        ret = process_enc_control_struct( psEnc, encControl );
        psEnc->sCmn.prefillFlag = 1;
    } else {
        /* Only accept input lengths that are a multiple of 10 ms */
        if( nBlocksOf10ms * psEnc->sCmn.API_fs_Hz != 100 * nSamplesIn || nSamplesIn < 0 ) {
            ret = SKP_SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES;
            SKP_assert( 0 );
            return( ret );
        }
        /* Make sure no more than one packet can be produced */
        if( 1000 * (SKP_int32)nSamplesIn > psEnc->sCmn.PacketSize_ms * psEnc->sCmn.API_fs_Hz ) {
            ret = SKP_SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES;
            SKP_assert( 0 );
            return( ret );
        }
    }

    /* Input buffering/resampling and encoding */
    while( 1 ) {
        nSamplesToBuffer = psEnc->sCmn.frame_length - psEnc->sCmn.inputBufIx;
        if( psEnc->sCmn.API_fs_Hz == SKP_SMULBB( 1000, psEnc->sCmn.fs_kHz ) ) { 
            nSamplesToBuffer  = SKP_min_int( nSamplesToBuffer, nSamplesIn );
            nSamplesFromInput = nSamplesToBuffer;
            /* Copy to buffer */
            SKP_memcpy( &psEnc->sCmn.inputBuf[ psEnc->sCmn.inputBufIx ], samplesIn, nSamplesFromInput * sizeof( SKP_int16 ) );
        } else {  
            nSamplesToBuffer  = SKP_min( nSamplesToBuffer, 10 * nBlocksOf10ms * psEnc->sCmn.fs_kHz );
            nSamplesFromInput = SKP_DIV32_16( nSamplesToBuffer * psEnc->sCmn.API_fs_Hz, psEnc->sCmn.fs_kHz * 1000 );
            /* Resample and write to buffer */
            ret += SKP_Silk_resampler( &psEnc->sCmn.resampler_state, &psEnc->sCmn.inputBuf[ psEnc->sCmn.inputBufIx ], samplesIn, nSamplesFromInput );
        } 
        samplesIn              += nSamplesFromInput;
        nSamplesIn             -= nSamplesFromInput;
        psEnc->sCmn.inputBufIx += nSamplesToBuffer;

        /* Silk encoder */
        if( psEnc->sCmn.inputBufIx >= psEnc->sCmn.frame_length ) {
            SKP_assert( psEnc->sCmn.inputBufIx == psEnc->sCmn.frame_length );

            /* Enough data in input buffer, so encode */
            if( ( ret = SKP_Silk_encode_frame_Fxx( psEnc, nBytesOut, psRangeEnc ) ) != 0 ) {
                SKP_assert( 0 );
            }
            psEnc->sCmn.inputBufIx = 0;
            psEnc->sCmn.controlled_since_last_payload = 0;

            if( nSamplesIn == 0 ) {
                break;
            }
        } else {
            break;
        }
    }

    if( prefillFlag ) {
        encControl->payloadSize_ms = tmp_payloadSize_ms;
        encControl->complexity = tmp_complexity;
        ret = process_enc_control_struct( psEnc, encControl );
        psEnc->sCmn.prefillFlag = 0;
    }

    return ret;
}
Example #25
0
/* Deactivate by setting psEncC->transition_frame_no = 0;   */
void SKP_Silk_LP_variable_cutoff(
    SKP_Silk_LP_state               *psLP,          /* I/O  LP filter state                     */
    SKP_int16                       *out,           /* O    Low-pass filtered output signal     */
    const SKP_int16                 *in,            /* I    Input signal                        */
    const SKP_int                   frame_length    /* I    Frame length                        */
)
{
    SKP_int32   B_Q28[ TRANSITION_NB ], A_Q28[ TRANSITION_NA ], fac_Q16 = 0;
    SKP_int     ind = 0;

    SKP_assert( psLP->transition_frame_no >= 0 );
    SKP_assert( ( ( ( psLP->transition_frame_no <= TRANSITION_FRAMES_DOWN ) && ( psLP->mode == 0 ) ) || 
                  ( ( psLP->transition_frame_no <= TRANSITION_FRAMES_UP   ) && ( psLP->mode == 1 ) ) ) );

    /* Interpolate filter coefficients if needed */
    if( psLP->transition_frame_no > 0 ) {
        if( psLP->mode == 0 ) {
            if( psLP->transition_frame_no < TRANSITION_FRAMES_DOWN ) {
                /* Calculate index and interpolation factor for interpolation */
#if( TRANSITION_INT_STEPS_DOWN == 32 )
                fac_Q16 = SKP_LSHIFT( psLP->transition_frame_no, 16 - 5 );
#else
                fac_Q16 = SKP_DIV32_16( SKP_LSHIFT( psLP->transition_frame_no, 16 ), TRANSITION_INT_STEPS_DOWN );
#endif
                ind      = SKP_RSHIFT( fac_Q16, 16 );
                fac_Q16 -= SKP_LSHIFT( ind, 16 );

                SKP_assert( ind >= 0 );
                SKP_assert( ind < TRANSITION_INT_NUM );

                /* Interpolate filter coefficients */
                SKP_Silk_LP_interpolate_filter_taps( B_Q28, A_Q28, ind, fac_Q16 );

                /* Increment transition frame number for next frame */
                psLP->transition_frame_no++;

            } else if( psLP->transition_frame_no == TRANSITION_FRAMES_DOWN ) {
                /* End of transition phase */
                SKP_Silk_LP_interpolate_filter_taps( B_Q28, A_Q28, TRANSITION_INT_NUM - 1, 0 );
            }
        } else if( psLP->mode == 1 ) {
            if( psLP->transition_frame_no < TRANSITION_FRAMES_UP ) {
                /* Calculate index and interpolation factor for interpolation */
#if( TRANSITION_INT_STEPS_UP == 64 )
                fac_Q16 = SKP_LSHIFT( TRANSITION_FRAMES_UP - psLP->transition_frame_no, 16 - 6 );
#else
                fac_Q16 = SKP_DIV32_16( SKP_LSHIFT( TRANSITION_FRAMES_UP - psLP->transition_frame_no, 16 ), TRANSITION_INT_STEPS_UP );
#endif
                ind      = SKP_RSHIFT( fac_Q16, 16 );
                fac_Q16 -= SKP_LSHIFT( ind, 16 );

                SKP_assert( ind >= 0 );
                SKP_assert( ind < TRANSITION_INT_NUM );

                /* Interpolate filter coefficients */
                SKP_Silk_LP_interpolate_filter_taps( B_Q28, A_Q28, ind, fac_Q16 );

                /* Increment transition frame number for next frame */
                psLP->transition_frame_no++;
            
            } else if( psLP->transition_frame_no == TRANSITION_FRAMES_UP ) {
                /* End of transition phase */
                SKP_Silk_LP_interpolate_filter_taps( B_Q28, A_Q28, 0, 0 );
            }
        }
    } 
    
    if( psLP->transition_frame_no > 0 ) {
        /* ARMA low-pass filtering */
        SKP_assert( TRANSITION_NB == 3 && TRANSITION_NA == 2 );
        SKP_Silk_biquad_alt( in, B_Q28, A_Q28, psLP->In_LP_State, out, frame_length );
    } else {
        /* Instead of using the filter, copy input directly to output */
        SKP_memcpy( out, in, frame_length * sizeof( SKP_int16 ) );
    }
}
/* High-pass filter with cutoff frequency adaptation based on pitch lag statistics */
void SKP_Silk_HP_variable_cutoff_FIX(
    SKP_Silk_encoder_state_FIX      *psEnc,             /* I/O  Encoder state FIX                           */
    SKP_Silk_encoder_control_FIX    *psEncCtrl,         /* I/O  Encoder control FIX                         */
    SKP_int16                       *out,               /* O    high-pass filtered output signal            */
    const SKP_int16                 *in                 /* I    input signal                                */
)
{
    SKP_int   quality_Q15;
    SKP_int32 B_Q28[ 3 ], A_Q28[ 2 ];
    SKP_int32 Fc_Q19, r_Q28, r_Q22;
    SKP_int32 pitch_freq_Hz_Q16, pitch_freq_log_Q7, delta_freq_Q7;

    /*********************************************/
    /* Estimate Low End of Pitch Frequency Range */
    /*********************************************/
    if( psEnc->sCmn.prev_sigtype == SIG_TYPE_VOICED ) {
        /* difference, in log domain */
        pitch_freq_Hz_Q16 = SKP_DIV32_16( SKP_LSHIFT( SKP_MUL( psEnc->sCmn.fs_kHz, 1000 ), 16 ), psEnc->sCmn.prevLag );
        pitch_freq_log_Q7 = SKP_Silk_lin2log( pitch_freq_Hz_Q16 ) - ( 16 << 7 ); //0x70

        /* adjustment based on quality */
        quality_Q15 = psEncCtrl->input_quality_bands_Q15[ 0 ];
        pitch_freq_log_Q7 = SKP_SUB32( pitch_freq_log_Q7, SKP_SMULWB( SKP_SMULWB( SKP_LSHIFT( quality_Q15, 2 ), quality_Q15 ), 
            pitch_freq_log_Q7 - SKP_LOG2_VARIABLE_HP_MIN_FREQ_Q7 ) );
        pitch_freq_log_Q7 = SKP_ADD32( pitch_freq_log_Q7, SKP_RSHIFT( SKP_FIX_CONST( 0.6, 15 ) - quality_Q15, 9 ) );

        //delta_freq = pitch_freq_log - psEnc->variable_HP_smth1;
        delta_freq_Q7 = pitch_freq_log_Q7 - SKP_RSHIFT( psEnc->variable_HP_smth1_Q15, 8 );
        if( delta_freq_Q7 < 0 ) {
            /* less smoothing for decreasing pitch frequency, to track something close to the minimum */
            delta_freq_Q7 = SKP_MUL( delta_freq_Q7, 3 );
        }

        /* limit delta, to reduce impact of outliers */
        delta_freq_Q7 = SKP_LIMIT_32( delta_freq_Q7, -SKP_FIX_CONST( VARIABLE_HP_MAX_DELTA_FREQ, 7 ), SKP_FIX_CONST( VARIABLE_HP_MAX_DELTA_FREQ, 7 ) );

        /* update smoother */
        psEnc->variable_HP_smth1_Q15 = SKP_SMLAWB( psEnc->variable_HP_smth1_Q15, 
            SKP_MUL( SKP_LSHIFT( psEnc->speech_activity_Q8, 1 ), delta_freq_Q7 ), SKP_FIX_CONST( VARIABLE_HP_SMTH_COEF1, 16 ) );
    }
    /* second smoother */
    psEnc->variable_HP_smth2_Q15 = SKP_SMLAWB( psEnc->variable_HP_smth2_Q15, 
        psEnc->variable_HP_smth1_Q15 - psEnc->variable_HP_smth2_Q15, SKP_FIX_CONST( VARIABLE_HP_SMTH_COEF2, 16 ) );

    /* convert from log scale to Hertz */
    psEncCtrl->pitch_freq_low_Hz = SKP_Silk_log2lin( SKP_RSHIFT( psEnc->variable_HP_smth2_Q15, 8 ) );

    /* limit frequency range */
    psEncCtrl->pitch_freq_low_Hz = SKP_LIMIT_32( psEncCtrl->pitch_freq_low_Hz, 
        SKP_FIX_CONST( VARIABLE_HP_MIN_FREQ, 0 ), SKP_FIX_CONST( VARIABLE_HP_MAX_FREQ, 0 ) );

    /********************************/
    /* Compute Filter Coefficients  */
    /********************************/
    /* compute cut-off frequency, in radians */
    //Fc_num   = (SKP_float)( 0.45f * 2.0f * 3.14159265359 * psEncCtrl->pitch_freq_low_Hz );
    //Fc_denom = (SKP_float)( 1e3f * psEnc->sCmn.fs_kHz );
    SKP_assert( psEncCtrl->pitch_freq_low_Hz <= SKP_int32_MAX / SKP_RADIANS_CONSTANT_Q19 );
    Fc_Q19 = SKP_DIV32_16( SKP_SMULBB( SKP_RADIANS_CONSTANT_Q19, psEncCtrl->pitch_freq_low_Hz ), psEnc->sCmn.fs_kHz ); // range: 3704 - 27787, 11-15 bits
    SKP_assert( Fc_Q19 >=  3704 );
    SKP_assert( Fc_Q19 <= 27787 );

    r_Q28 = SKP_FIX_CONST( 1.0, 28 ) - SKP_MUL( SKP_FIX_CONST( 0.92, 9 ), Fc_Q19 );
    SKP_assert( r_Q28 >= 255347779 );
    SKP_assert( r_Q28 <= 266690872 );

    /* b = r * [ 1; -2; 1 ]; */
    /* a = [ 1; -2 * r * ( 1 - 0.5 * Fc^2 ); r^2 ]; */
    B_Q28[ 0 ] = r_Q28;
    B_Q28[ 1 ] = SKP_LSHIFT( -r_Q28, 1 );
    B_Q28[ 2 ] = r_Q28;
    
    // -r * ( 2 - Fc * Fc );
    r_Q22  = SKP_RSHIFT( r_Q28, 6 );
    A_Q28[ 0 ] = SKP_SMULWW( r_Q22, SKP_SMULWW( Fc_Q19, Fc_Q19 ) - SKP_FIX_CONST( 2.0,  22 ) );
    A_Q28[ 1 ] = SKP_SMULWW( r_Q22, r_Q22 );

    /********************************/
    /* High-Pass Filter             */
    /********************************/
    SKP_Silk_biquad_alt( in, B_Q28, A_Q28, psEnc->sCmn.In_HP_State, out, psEnc->sCmn.frame_length );
}
/* Control internal sampling rate */
SKP_int silk_control_audio_bandwidth(
    silk_encoder_state      *psEncC             /* I/O  Pointer to Silk encoder state               */
)
{
    SKP_int   fs_kHz;
    SKP_int32 fs_Hz;
    
    fs_kHz = psEncC->fs_kHz;
    fs_Hz = SKP_SMULBB( fs_kHz, 1000 );
    if( fs_Hz == 0 ) {
        /* Encoder has just been initialized */
        fs_Hz  = SKP_min( psEncC->desiredInternal_fs_Hz, psEncC->API_fs_Hz );
        fs_kHz = SKP_DIV32_16( fs_Hz, 1000 );
    } else if( fs_Hz > psEncC->API_fs_Hz || fs_Hz > psEncC->maxInternal_fs_Hz || fs_Hz < psEncC->minInternal_fs_Hz ) {
        /* Make sure internal rate is not higher than external rate or maximum allowed, or lower than minimum allowed */
        fs_Hz  = psEncC->API_fs_Hz;
        fs_Hz  = SKP_min( fs_Hz, psEncC->maxInternal_fs_Hz );
        fs_Hz  = SKP_max( fs_Hz, psEncC->minInternal_fs_Hz );
        fs_kHz = SKP_DIV32_16( fs_Hz, 1000 );
    } else {
        /* State machine for the internal sampling rate switching */
        if( psEncC->sLP.transition_frame_no >= TRANSITION_FRAMES ) {
            /* Stop transition phase */
            psEncC->sLP.mode = 0;
        }
        if( psEncC->allow_bandwidth_switch ) {
            /* Check if we should switch down */
            if( SKP_SMULBB( psEncC->fs_kHz, 1000 ) > psEncC->desiredInternal_fs_Hz ) 
            {
                /* Switch down */
                if( psEncC->sLP.mode == 0 ) {
                    /* New transition */
                    psEncC->sLP.transition_frame_no = TRANSITION_FRAMES;

                    /* Reset transition filter state */
                    SKP_memset( psEncC->sLP.In_LP_State, 0, sizeof( psEncC->sLP.In_LP_State ) );
                } 
                if( psEncC->sLP.transition_frame_no <= 0 ) {
                    /* Stop transition phase */
                    psEncC->sLP.mode = 0;

                    /* Switch to a lower sample frequency */
                    fs_kHz = psEncC->fs_kHz == 16 ? 12 : 8;
                } else {
                    /* Direction: down (at double speed) */
                    psEncC->sLP.mode = -2;
                } 
            } 
            else
            /* Check if we should switch up */
            if( SKP_SMULBB( psEncC->fs_kHz, 1000 ) < psEncC->desiredInternal_fs_Hz ) 
            {
                /* Switch up */
                if( psEncC->sLP.mode == 0 ) {
                    /* Switch to a higher sample frequency */
                    fs_kHz = psEncC->fs_kHz == 8 ? 12 : 16;

                    /* New transition */
                    psEncC->sLP.transition_frame_no = 0;

                    /* Reset transition filter state */
                    SKP_memset( psEncC->sLP.In_LP_State, 0, sizeof( psEncC->sLP.In_LP_State ) );
                } 
                /* Direction: up */
                psEncC->sLP.mode = 1;
            }
        }
    }

#ifdef FORCE_INTERNAL_FS_KHZ
    fs_kHz = FORCE_INTERNAL_FS_KHZ;
#endif

    return fs_kHz;
}