ref: fe741259c1050baa5c828444dd5a968ed658d1fb
dir: /silk/SKP_Silk_process_NLSFs.c/
/***********************************************************************
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***********************************************************************/
#include "SKP_Silk_main.h"
/* Limit, stabilize, convert and quantize NLSFs */
void SKP_Silk_process_NLSFs(
SKP_Silk_encoder_state *psEncC, /* I/O Encoder state */
SKP_int16 PredCoef_Q12[ 2 ][ MAX_LPC_ORDER ], /* O Prediction coefficients */
SKP_int16 pNLSF_Q15[ MAX_LPC_ORDER ], /* I/O Normalized LSFs (quant out) (0 - (2^15-1)) */
const SKP_int16 prev_NLSFq_Q15[ MAX_LPC_ORDER ] /* I Previous Normalized LSFs (0 - (2^15-1)) */
)
{
SKP_int i, doInterpolate;
SKP_int16 pNLSFW_Q5[ MAX_LPC_ORDER ];
SKP_int NLSF_mu_Q20;
SKP_int32 i_sqr_Q15;
SKP_int16 pNLSF0_temp_Q15[ MAX_LPC_ORDER ];
SKP_int16 pNLSFW0_temp_Q5[ MAX_LPC_ORDER ];
SKP_assert( psEncC->speech_activity_Q8 >= 0 );
SKP_assert( psEncC->speech_activity_Q8 <= SKP_FIX_CONST( 1.0, 8 ) );
/***********************/
/* Calculate mu values */
/***********************/
/* NLSF_mu = 0.003 - 0.0015 * psEnc->speech_activity; */
NLSF_mu_Q20 = SKP_SMLAWB( SKP_FIX_CONST( 0.003, 20 ), SKP_FIX_CONST( -0.0015, 28 ), psEncC->speech_activity_Q8 );
if( psEncC->nb_subfr == 2 ) {
/* Multiply by 1.5 for 10 ms packets */
NLSF_mu_Q20 = SKP_ADD_RSHIFT( NLSF_mu_Q20, NLSF_mu_Q20, 1 );
}
SKP_assert( NLSF_mu_Q20 > 0 );
SKP_assert( NLSF_mu_Q20 <= SKP_FIX_CONST( 0.0045, 20 ) );
/* Calculate NLSF weights */
SKP_Silk_NLSF_VQ_weights_laroia( pNLSFW_Q5, pNLSF_Q15, psEncC->predictLPCOrder );
/* Update NLSF weights for interpolated NLSFs */
doInterpolate = ( psEncC->useInterpolatedNLSFs == 1 ) && ( psEncC->indices.NLSFInterpCoef_Q2 < 4 );
if( doInterpolate ) {
/* Calculate the interpolated NLSF vector for the first half */
SKP_Silk_interpolate( pNLSF0_temp_Q15, prev_NLSFq_Q15, pNLSF_Q15,
psEncC->indices.NLSFInterpCoef_Q2, psEncC->predictLPCOrder );
/* Calculate first half NLSF weights for the interpolated NLSFs */
SKP_Silk_NLSF_VQ_weights_laroia( pNLSFW0_temp_Q5, pNLSF0_temp_Q15, psEncC->predictLPCOrder );
/* Update NLSF weights with contribution from first half */
i_sqr_Q15 = SKP_LSHIFT( SKP_SMULBB( psEncC->indices.NLSFInterpCoef_Q2, psEncC->indices.NLSFInterpCoef_Q2 ), 11 );
for( i = 0; i < psEncC->predictLPCOrder; i++ ) {
pNLSFW_Q5[ i ] = SKP_SMLAWB( SKP_RSHIFT( pNLSFW_Q5[ i ], 1 ), pNLSFW0_temp_Q5[ i ], i_sqr_Q15 );
SKP_assert( pNLSFW_Q5[ i ] <= SKP_int16_MAX );
SKP_assert( pNLSFW_Q5[ i ] >= 1 );
}
}
TIC(NLSF_encode)
SKP_Silk_NLSF_encode( psEncC->indices.NLSFIndices, pNLSF_Q15, psEncC->psNLSF_CB, pNLSFW_Q5,
NLSF_mu_Q20, psEncC->NLSF_MSVQ_Survivors, psEncC->indices.signalType );
TOC(NLSF_encode)
/* Convert quantized NLSFs back to LPC coefficients */
SKP_Silk_NLSF2A_stable( PredCoef_Q12[ 1 ], pNLSF_Q15, psEncC->predictLPCOrder );
if( doInterpolate ) {
/* Calculate the interpolated, quantized LSF vector for the first half */
SKP_Silk_interpolate( pNLSF0_temp_Q15, prev_NLSFq_Q15, pNLSF_Q15,
psEncC->indices.NLSFInterpCoef_Q2, psEncC->predictLPCOrder );
/* Convert back to LPC coefficients */
SKP_Silk_NLSF2A_stable( PredCoef_Q12[ 0 ], pNLSF0_temp_Q15, psEncC->predictLPCOrder );
} else {
/* Copy LPC coefficients for first half from second half */
SKP_memcpy( PredCoef_Q12[ 0 ], PredCoef_Q12[ 1 ], psEncC->predictLPCOrder * sizeof( SKP_int16 ) );
}
}