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27 
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31 
32 #include "main.h"
33 #include "stack_alloc.h"
34 
35 /***********************/
36 /* NLSF vector encoder */
37 /***********************/
silk_NLSF_encode(opus_int8 * NLSFIndices,opus_int16 * pNLSF_Q15,const silk_NLSF_CB_struct * psNLSF_CB,const opus_int16 * pW_QW,const opus_int NLSF_mu_Q20,const opus_int nSurvivors,const opus_int signalType)38 opus_int32 silk_NLSF_encode(                                    /* O    Returns RD value in Q25                     */
39           opus_int8             *NLSFIndices,                   /* I    Codebook path vector [ LPC_ORDER + 1 ]      */
40           opus_int16            *pNLSF_Q15,                     /* I/O  Quantized NLSF vector [ LPC_ORDER ]         */
41     const silk_NLSF_CB_struct   *psNLSF_CB,                     /* I    Codebook object                             */
42     const opus_int16            *pW_QW,                         /* I    NLSF weight vector [ LPC_ORDER ]            */
43     const opus_int              NLSF_mu_Q20,                    /* I    Rate weight for the RD optimization         */
44     const opus_int              nSurvivors,                     /* I    Max survivors after first stage             */
45     const opus_int              signalType                      /* I    Signal type: 0/1/2                          */
46 )
47 {
48     opus_int         i, s, ind1, bestIndex, prob_Q8, bits_q7;
49     opus_int32       W_tmp_Q9;
50     VARDECL( opus_int32, err_Q26 );
51     VARDECL( opus_int32, RD_Q25 );
52     VARDECL( opus_int, tempIndices1 );
53     VARDECL( opus_int8, tempIndices2 );
54     opus_int16       res_Q15[      MAX_LPC_ORDER ];
55     opus_int16       res_Q10[      MAX_LPC_ORDER ];
56     opus_int16       NLSF_tmp_Q15[ MAX_LPC_ORDER ];
57     opus_int16       W_tmp_QW[     MAX_LPC_ORDER ];
58     opus_int16       W_adj_Q5[     MAX_LPC_ORDER ];
59     opus_uint8       pred_Q8[      MAX_LPC_ORDER ];
60     opus_int16       ec_ix[        MAX_LPC_ORDER ];
61     const opus_uint8 *pCB_element, *iCDF_ptr;
62     SAVE_STACK;
63 
64     silk_assert( nSurvivors <= NLSF_VQ_MAX_SURVIVORS );
65     silk_assert( signalType >= 0 && signalType <= 2 );
66     silk_assert( NLSF_mu_Q20 <= 32767 && NLSF_mu_Q20 >= 0 );
67 
68     /* NLSF stabilization */
69     silk_NLSF_stabilize( pNLSF_Q15, psNLSF_CB->deltaMin_Q15, psNLSF_CB->order );
70 
71     /* First stage: VQ */
72     ALLOC( err_Q26, psNLSF_CB->nVectors, opus_int32 );
73     silk_NLSF_VQ( err_Q26, pNLSF_Q15, psNLSF_CB->CB1_NLSF_Q8, psNLSF_CB->nVectors, psNLSF_CB->order );
74 
75     /* Sort the quantization errors */
76     ALLOC( tempIndices1, nSurvivors, opus_int );
77     silk_insertion_sort_increasing( err_Q26, tempIndices1, psNLSF_CB->nVectors, nSurvivors );
78 
79     ALLOC( RD_Q25, nSurvivors, opus_int32 );
80     ALLOC( tempIndices2, nSurvivors * MAX_LPC_ORDER, opus_int8 );
81 
82     /* Loop over survivors */
83     for( s = 0; s < nSurvivors; s++ ) {
84         ind1 = tempIndices1[ s ];
85 
86         /* Residual after first stage */
87         pCB_element = &psNLSF_CB->CB1_NLSF_Q8[ ind1 * psNLSF_CB->order ];
88         for( i = 0; i < psNLSF_CB->order; i++ ) {
89             NLSF_tmp_Q15[ i ] = silk_LSHIFT16( (opus_int16)pCB_element[ i ], 7 );
90             res_Q15[ i ] = pNLSF_Q15[ i ] - NLSF_tmp_Q15[ i ];
91         }
92 
93         /* Weights from codebook vector */
94         silk_NLSF_VQ_weights_laroia( W_tmp_QW, NLSF_tmp_Q15, psNLSF_CB->order );
95 
96         /* Apply square-rooted weights */
97         for( i = 0; i < psNLSF_CB->order; i++ ) {
98             W_tmp_Q9 = silk_SQRT_APPROX( silk_LSHIFT( (opus_int32)W_tmp_QW[ i ], 18 - NLSF_W_Q ) );
99             res_Q10[ i ] = (opus_int16)silk_RSHIFT( silk_SMULBB( res_Q15[ i ], W_tmp_Q9 ), 14 );
100         }
101 
102         /* Modify input weights accordingly */
103         for( i = 0; i < psNLSF_CB->order; i++ ) {
104             W_adj_Q5[ i ] = silk_DIV32_16( silk_LSHIFT( (opus_int32)pW_QW[ i ], 5 ), W_tmp_QW[ i ] );
105         }
106 
107         /* Unpack entropy table indices and predictor for current CB1 index */
108         silk_NLSF_unpack( ec_ix, pred_Q8, psNLSF_CB, ind1 );
109 
110         /* Trellis quantizer */
111         RD_Q25[ s ] = silk_NLSF_del_dec_quant( &tempIndices2[ s * MAX_LPC_ORDER ], res_Q10, W_adj_Q5, pred_Q8, ec_ix,
112             psNLSF_CB->ec_Rates_Q5, psNLSF_CB->quantStepSize_Q16, psNLSF_CB->invQuantStepSize_Q6, NLSF_mu_Q20, psNLSF_CB->order );
113 
114         /* Add rate for first stage */
115         iCDF_ptr = &psNLSF_CB->CB1_iCDF[ ( signalType >> 1 ) * psNLSF_CB->nVectors ];
116         if( ind1 == 0 ) {
117             prob_Q8 = 256 - iCDF_ptr[ ind1 ];
118         } else {
119             prob_Q8 = iCDF_ptr[ ind1 - 1 ] - iCDF_ptr[ ind1 ];
120         }
121         bits_q7 = ( 8 << 7 ) - silk_lin2log( prob_Q8 );
122         RD_Q25[ s ] = silk_SMLABB( RD_Q25[ s ], bits_q7, silk_RSHIFT( NLSF_mu_Q20, 2 ) );
123     }
124 
125     /* Find the lowest rate-distortion error */
126     silk_insertion_sort_increasing( RD_Q25, &bestIndex, nSurvivors, 1 );
127 
128     NLSFIndices[ 0 ] = (opus_int8)tempIndices1[ bestIndex ];
129     silk_memcpy( &NLSFIndices[ 1 ], &tempIndices2[ bestIndex * MAX_LPC_ORDER ], psNLSF_CB->order * sizeof( opus_int8 ) );
130 
131     /* Decode */
132     silk_NLSF_decode( pNLSF_Q15, NLSFIndices, psNLSF_CB );
133 
134     RESTORE_STACK;
135     return RD_Q25[ 0 ];
136 }
137