revoice/dep/silk/src/SKP_Silk_process_NLSFs_FLP.c

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#include <stdlib.h>
#include "SKP_Silk_main_FLP.h"

/* Limit, stabilize, convert and quantize NLSFs */
void SKP_Silk_process_NLSFs_FLP(
    SKP_Silk_encoder_state_FLP      *psEnc,             /* I/O  Encoder state FLP                       */
    SKP_Silk_encoder_control_FLP    *psEncCtrl,         /* I/O  Encoder control FLP                     */
    SKP_float                       *pNLSF              /* I/O  NLSFs (quantized output)                */
)
{
    SKP_int     doInterpolate;
    SKP_float   pNLSFW[ MAX_LPC_ORDER ];
    SKP_float   NLSF_mu, NLSF_mu_fluc_red, i_sqr, NLSF_interpolation_factor = 0.0f;
    const SKP_Silk_NLSF_CB_FLP *psNLSF_CB_FLP;

    /* Used only for NLSF interpolation */
    SKP_float   pNLSF0_temp[  MAX_LPC_ORDER ];
    SKP_float   pNLSFW0_temp[ MAX_LPC_ORDER ];
    SKP_int     i;

    SKP_assert( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED || psEncCtrl->sCmn.sigtype == SIG_TYPE_UNVOICED );

    /***********************/
    /* Calculate mu values */
    /***********************/
    if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) {
        NLSF_mu          = 0.002f - 0.001f * psEnc->speech_activity;
        NLSF_mu_fluc_red = 0.1f   - 0.05f  * psEnc->speech_activity;
    } else { 
        NLSF_mu          = 0.005f - 0.004f * psEnc->speech_activity;
        NLSF_mu_fluc_red = 0.2f   - 0.1f   * ( psEnc->speech_activity + psEncCtrl->sparseness );
    }

    /* Calculate NLSF weights */
    SKP_Silk_NLSF_VQ_weights_laroia_FLP( pNLSFW, pNLSF, psEnc->sCmn.predictLPCOrder );

    /* Update NLSF weights for interpolated NLSFs */
    doInterpolate = ( psEnc->sCmn.useInterpolatedNLSFs == 1 ) && ( psEncCtrl->sCmn.NLSFInterpCoef_Q2 < ( 1 << 2 ) );
    if( doInterpolate ) {

        /* Calculate the interpolated NLSF vector for the first half */
        NLSF_interpolation_factor = 0.25f * psEncCtrl->sCmn.NLSFInterpCoef_Q2;
        SKP_Silk_interpolate_wrapper_FLP( pNLSF0_temp, psEnc->sPred.prev_NLSFq, pNLSF, 
            NLSF_interpolation_factor, psEnc->sCmn.predictLPCOrder );

        /* Calculate first half NLSF weights for the interpolated NLSFs */
        SKP_Silk_NLSF_VQ_weights_laroia_FLP( pNLSFW0_temp, pNLSF0_temp, psEnc->sCmn.predictLPCOrder );

        /* Update NLSF weights with contribution from first half */
        i_sqr = NLSF_interpolation_factor * NLSF_interpolation_factor;
        for( i = 0; i < psEnc->sCmn.predictLPCOrder; i++ ) {
            pNLSFW[ i ] = 0.5f * ( pNLSFW[ i ] + i_sqr * pNLSFW0_temp[ i ] );
        }
    }

    /* Set pointer to the NLSF codebook for the current signal type and LPC order */
    psNLSF_CB_FLP = psEnc->psNLSF_CB_FLP[ psEncCtrl->sCmn.sigtype ];

    /* Quantize NLSF parameters given the trained NLSF codebooks */
    SKP_Silk_NLSF_MSVQ_encode_FLP( psEncCtrl->sCmn.NLSFIndices, pNLSF, psNLSF_CB_FLP, psEnc->sPred.prev_NLSFq, pNLSFW, NLSF_mu, 
        NLSF_mu_fluc_red, psEnc->sCmn.NLSF_MSVQ_Survivors, psEnc->sCmn.predictLPCOrder, psEnc->sCmn.first_frame_after_reset );

    /* Convert quantized NLSFs back to LPC coefficients */
    SKP_Silk_NLSF2A_stable_FLP( psEncCtrl->PredCoef[ 1 ], pNLSF, psEnc->sCmn.predictLPCOrder );

    if( doInterpolate ) {
        /* Calculate the interpolated, quantized NLSF vector for the first half */
        SKP_Silk_interpolate_wrapper_FLP( pNLSF0_temp, psEnc->sPred.prev_NLSFq, pNLSF, 
            NLSF_interpolation_factor, psEnc->sCmn.predictLPCOrder );

        /* Convert back to LPC coefficients */
        SKP_Silk_NLSF2A_stable_FLP( psEncCtrl->PredCoef[ 0 ], pNLSF0_temp, psEnc->sCmn.predictLPCOrder );

    } else {
        /* Copy LPC coefficients for first half from second half */
        SKP_memcpy( psEncCtrl->PredCoef[ 0 ], psEncCtrl->PredCoef[ 1 ], psEnc->sCmn.predictLPCOrder * sizeof( SKP_float ) );
    }
}