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27 
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31 
32 #include "main.h"
33 
34 /* Limit, stabilize, convert and quantize NLSFs */
silk_process_NLSFs(silk_encoder_state * psEncC,opus_int16 PredCoef_Q12[2][MAX_LPC_ORDER],opus_int16 pNLSF_Q15[MAX_LPC_ORDER],const opus_int16 prev_NLSFq_Q15[MAX_LPC_ORDER])35 void silk_process_NLSFs(
36     silk_encoder_state          *psEncC,                            /* I/O  Encoder state                               */
37     opus_int16                  PredCoef_Q12[ 2 ][ MAX_LPC_ORDER ], /* O    Prediction coefficients                     */
38     opus_int16                  pNLSF_Q15[         MAX_LPC_ORDER ], /* I/O  Normalized LSFs (quant out) (0 - (2^15-1))  */
39     const opus_int16            prev_NLSFq_Q15[    MAX_LPC_ORDER ]  /* I    Previous Normalized LSFs (0 - (2^15-1))     */
40 )
41 {
42     opus_int     i, doInterpolate;
43     opus_int     NLSF_mu_Q20;
44     opus_int16   i_sqr_Q15;
45     opus_int16   pNLSF0_temp_Q15[ MAX_LPC_ORDER ];
46     opus_int16   pNLSFW_QW[ MAX_LPC_ORDER ];
47     opus_int16   pNLSFW0_temp_QW[ MAX_LPC_ORDER ];
48 
49     silk_assert( psEncC->speech_activity_Q8 >=   0 );
50     silk_assert( psEncC->speech_activity_Q8 <= SILK_FIX_CONST( 1.0, 8 ) );
51     silk_assert( psEncC->useInterpolatedNLSFs == 1 || psEncC->indices.NLSFInterpCoef_Q2 == ( 1 << 2 ) );
52 
53     /***********************/
54     /* Calculate mu values */
55     /***********************/
56     /* NLSF_mu  = 0.003 - 0.0015 * psEnc->speech_activity; */
57     NLSF_mu_Q20 = silk_SMLAWB( SILK_FIX_CONST( 0.003, 20 ), SILK_FIX_CONST( -0.001, 28 ), psEncC->speech_activity_Q8 );
58     if( psEncC->nb_subfr == 2 ) {
59         /* Multiply by 1.5 for 10 ms packets */
60         NLSF_mu_Q20 = silk_ADD_RSHIFT( NLSF_mu_Q20, NLSF_mu_Q20, 1 );
61     }
62 
63     silk_assert( NLSF_mu_Q20 >  0 );
64     silk_assert( NLSF_mu_Q20 <= SILK_FIX_CONST( 0.005, 20 ) );
65 
66     /* Calculate NLSF weights */
67     silk_NLSF_VQ_weights_laroia( pNLSFW_QW, pNLSF_Q15, psEncC->predictLPCOrder );
68 
69     /* Update NLSF weights for interpolated NLSFs */
70     doInterpolate = ( psEncC->useInterpolatedNLSFs == 1 ) && ( psEncC->indices.NLSFInterpCoef_Q2 < 4 );
71     if( doInterpolate ) {
72         /* Calculate the interpolated NLSF vector for the first half */
73         silk_interpolate( pNLSF0_temp_Q15, prev_NLSFq_Q15, pNLSF_Q15,
74             psEncC->indices.NLSFInterpCoef_Q2, psEncC->predictLPCOrder );
75 
76         /* Calculate first half NLSF weights for the interpolated NLSFs */
77         silk_NLSF_VQ_weights_laroia( pNLSFW0_temp_QW, pNLSF0_temp_Q15, psEncC->predictLPCOrder );
78 
79         /* Update NLSF weights with contribution from first half */
80         i_sqr_Q15 = silk_LSHIFT( silk_SMULBB( psEncC->indices.NLSFInterpCoef_Q2, psEncC->indices.NLSFInterpCoef_Q2 ), 11 );
81         for( i = 0; i < psEncC->predictLPCOrder; i++ ) {
82             pNLSFW_QW[ i ] = silk_ADD16( silk_RSHIFT( pNLSFW_QW[ i ], 1 ), silk_RSHIFT(
83                   silk_SMULBB( pNLSFW0_temp_QW[ i ], i_sqr_Q15 ), 16) );
84             silk_assert( pNLSFW_QW[ i ] >= 1 );
85         }
86     }
87 
88     silk_NLSF_encode( psEncC->indices.NLSFIndices, pNLSF_Q15, psEncC->psNLSF_CB, pNLSFW_QW,
89         NLSF_mu_Q20, psEncC->NLSF_MSVQ_Survivors, psEncC->indices.signalType );
90 
91     /* Convert quantized NLSFs back to LPC coefficients */
92     silk_NLSF2A( PredCoef_Q12[ 1 ], pNLSF_Q15, psEncC->predictLPCOrder, psEncC->arch );
93 
94     if( doInterpolate ) {
95         /* Calculate the interpolated, quantized LSF vector for the first half */
96         silk_interpolate( pNLSF0_temp_Q15, prev_NLSFq_Q15, pNLSF_Q15,
97             psEncC->indices.NLSFInterpCoef_Q2, psEncC->predictLPCOrder );
98 
99         /* Convert back to LPC coefficients */
100         silk_NLSF2A( PredCoef_Q12[ 0 ], pNLSF0_temp_Q15, psEncC->predictLPCOrder, psEncC->arch );
101 
102     } else {
103         /* Copy LPC coefficients for first half from second half */
104         silk_assert( psEncC->predictLPCOrder <= MAX_LPC_ORDER );
105         silk_memcpy( PredCoef_Q12[ 0 ], PredCoef_Q12[ 1 ], psEncC->predictLPCOrder * sizeof( opus_int16 ) );
106     }
107 }
108