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26 ***********************************************************************/
27 
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31 
32 #include "main.h"
33 
34 /* Decode parameters from payload */
silk_decode_parameters(silk_decoder_state * psDec,silk_decoder_control * psDecCtrl,opus_int condCoding)35 void silk_decode_parameters(
36     silk_decoder_state          *psDec,                         /* I/O  State                                       */
37     silk_decoder_control        *psDecCtrl,                     /* I/O  Decoder control                             */
38     opus_int                    condCoding                      /* I    The type of conditional coding to use       */
39 )
40 {
41     opus_int   i, k, Ix;
42     opus_int16 pNLSF_Q15[ MAX_LPC_ORDER ], pNLSF0_Q15[ MAX_LPC_ORDER ];
43     const opus_int8 *cbk_ptr_Q7;
44 
45     /* Dequant Gains */
46     silk_gains_dequant( psDecCtrl->Gains_Q16, psDec->indices.GainsIndices,
47         &psDec->LastGainIndex, condCoding == CODE_CONDITIONALLY, psDec->nb_subfr );
48 
49     /****************/
50     /* Decode NLSFs */
51     /****************/
52     silk_NLSF_decode( pNLSF_Q15, psDec->indices.NLSFIndices, psDec->psNLSF_CB );
53 
54     /* Convert NLSF parameters to AR prediction filter coefficients */
55     silk_NLSF2A( psDecCtrl->PredCoef_Q12[ 1 ], pNLSF_Q15, psDec->LPC_order );
56 
57     /* If just reset, e.g., because internal Fs changed, do not allow interpolation */
58     /* improves the case of packet loss in the first frame after a switch           */
59     if( psDec->first_frame_after_reset == 1 ) {
60         psDec->indices.NLSFInterpCoef_Q2 = 4;
61     }
62 
63     if( psDec->indices.NLSFInterpCoef_Q2 < 4 ) {
64         /* Calculation of the interpolated NLSF0 vector from the interpolation factor, */
65         /* the previous NLSF1, and the current NLSF1                                   */
66         for( i = 0; i < psDec->LPC_order; i++ ) {
67             pNLSF0_Q15[ i ] = psDec->prevNLSF_Q15[ i ] + silk_RSHIFT( silk_MUL( psDec->indices.NLSFInterpCoef_Q2,
68                 pNLSF_Q15[ i ] - psDec->prevNLSF_Q15[ i ] ), 2 );
69         }
70 
71         /* Convert NLSF parameters to AR prediction filter coefficients */
72         silk_NLSF2A( psDecCtrl->PredCoef_Q12[ 0 ], pNLSF0_Q15, psDec->LPC_order );
73     } else {
74         /* Copy LPC coefficients for first half from second half */
75         silk_memcpy( psDecCtrl->PredCoef_Q12[ 0 ], psDecCtrl->PredCoef_Q12[ 1 ], psDec->LPC_order * sizeof( opus_int16 ) );
76     }
77 
78     silk_memcpy( psDec->prevNLSF_Q15, pNLSF_Q15, psDec->LPC_order * sizeof( opus_int16 ) );
79 
80     /* After a packet loss do BWE of LPC coefs */
81     if( psDec->lossCnt ) {
82         silk_bwexpander( psDecCtrl->PredCoef_Q12[ 0 ], psDec->LPC_order, BWE_AFTER_LOSS_Q16 );
83         silk_bwexpander( psDecCtrl->PredCoef_Q12[ 1 ], psDec->LPC_order, BWE_AFTER_LOSS_Q16 );
84     }
85 
86     if( psDec->indices.signalType == TYPE_VOICED ) {
87         /*********************/
88         /* Decode pitch lags */
89         /*********************/
90 
91         /* Decode pitch values */
92         silk_decode_pitch( psDec->indices.lagIndex, psDec->indices.contourIndex, psDecCtrl->pitchL, psDec->fs_kHz, psDec->nb_subfr );
93 
94         /* Decode Codebook Index */
95         cbk_ptr_Q7 = silk_LTP_vq_ptrs_Q7[ psDec->indices.PERIndex ]; /* set pointer to start of codebook */
96 
97         for( k = 0; k < psDec->nb_subfr; k++ ) {
98             Ix = psDec->indices.LTPIndex[ k ];
99             for( i = 0; i < LTP_ORDER; i++ ) {
100                 psDecCtrl->LTPCoef_Q14[ k * LTP_ORDER + i ] = silk_LSHIFT( cbk_ptr_Q7[ Ix * LTP_ORDER + i ], 7 );
101             }
102         }
103 
104         /**********************/
105         /* Decode LTP scaling */
106         /**********************/
107         Ix = psDec->indices.LTP_scaleIndex;
108         psDecCtrl->LTP_scale_Q14 = silk_LTPScales_table_Q14[ Ix ];
109     } else {
110         silk_memset( psDecCtrl->pitchL,      0,             psDec->nb_subfr * sizeof( opus_int   ) );
111         silk_memset( psDecCtrl->LTPCoef_Q14, 0, LTP_ORDER * psDec->nb_subfr * sizeof( opus_int16 ) );
112         psDec->indices.PERIndex  = 0;
113         psDecCtrl->LTP_scale_Q14 = 0;
114     }
115 }
116