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26 ***********************************************************************/
27
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31
32 #include "main.h"
33
34 /* Predictive dequantizer for NLSF residuals */
silk_NLSF_residual_dequant(opus_int16 x_Q10[],const opus_int8 indices[],const opus_uint8 pred_coef_Q8[],const opus_int quant_step_size_Q16,const opus_int16 order)35 static OPUS_INLINE void silk_NLSF_residual_dequant( /* O Returns RD value in Q30 */
36 opus_int16 x_Q10[], /* O Output [ order ] */
37 const opus_int8 indices[], /* I Quantization indices [ order ] */
38 const opus_uint8 pred_coef_Q8[], /* I Backward predictor coefs [ order ] */
39 const opus_int quant_step_size_Q16, /* I Quantization step size */
40 const opus_int16 order /* I Number of input values */
41 )
42 {
43 opus_int i, out_Q10, pred_Q10;
44
45 out_Q10 = 0;
46 for( i = order-1; i >= 0; i-- ) {
47 pred_Q10 = silk_RSHIFT( silk_SMULBB( out_Q10, (opus_int16)pred_coef_Q8[ i ] ), 8 );
48 out_Q10 = silk_LSHIFT( indices[ i ], 10 );
49 if( out_Q10 > 0 ) {
50 out_Q10 = silk_SUB16( out_Q10, SILK_FIX_CONST( NLSF_QUANT_LEVEL_ADJ, 10 ) );
51 } else if( out_Q10 < 0 ) {
52 out_Q10 = silk_ADD16( out_Q10, SILK_FIX_CONST( NLSF_QUANT_LEVEL_ADJ, 10 ) );
53 }
54 out_Q10 = silk_SMLAWB( pred_Q10, (opus_int32)out_Q10, quant_step_size_Q16 );
55 x_Q10[ i ] = out_Q10;
56 }
57 }
58
59
60 /***********************/
61 /* NLSF vector decoder */
62 /***********************/
silk_NLSF_decode(opus_int16 * pNLSF_Q15,opus_int8 * NLSFIndices,const silk_NLSF_CB_struct * psNLSF_CB)63 void silk_NLSF_decode(
64 opus_int16 *pNLSF_Q15, /* O Quantized NLSF vector [ LPC_ORDER ] */
65 opus_int8 *NLSFIndices, /* I Codebook path vector [ LPC_ORDER + 1 ] */
66 const silk_NLSF_CB_struct *psNLSF_CB /* I Codebook object */
67 )
68 {
69 opus_int i;
70 opus_uint8 pred_Q8[ MAX_LPC_ORDER ];
71 opus_int16 ec_ix[ MAX_LPC_ORDER ];
72 opus_int16 res_Q10[ MAX_LPC_ORDER ];
73 opus_int16 W_tmp_QW[ MAX_LPC_ORDER ];
74 opus_int32 W_tmp_Q9, NLSF_Q15_tmp;
75 const opus_uint8 *pCB_element;
76
77 /* Decode first stage */
78 pCB_element = &psNLSF_CB->CB1_NLSF_Q8[ NLSFIndices[ 0 ] * psNLSF_CB->order ];
79 for( i = 0; i < psNLSF_CB->order; i++ ) {
80 pNLSF_Q15[ i ] = silk_LSHIFT( (opus_int16)pCB_element[ i ], 7 );
81 }
82
83 /* Unpack entropy table indices and predictor for current CB1 index */
84 silk_NLSF_unpack( ec_ix, pred_Q8, psNLSF_CB, NLSFIndices[ 0 ] );
85
86 /* Predictive residual dequantizer */
87 silk_NLSF_residual_dequant( res_Q10, &NLSFIndices[ 1 ], pred_Q8, psNLSF_CB->quantStepSize_Q16, psNLSF_CB->order );
88
89 /* Weights from codebook vector */
90 silk_NLSF_VQ_weights_laroia( W_tmp_QW, pNLSF_Q15, psNLSF_CB->order );
91
92 /* Apply inverse square-rooted weights and add to output */
93 for( i = 0; i < psNLSF_CB->order; i++ ) {
94 W_tmp_Q9 = silk_SQRT_APPROX( silk_LSHIFT( (opus_int32)W_tmp_QW[ i ], 18 - NLSF_W_Q ) );
95 NLSF_Q15_tmp = silk_ADD32( pNLSF_Q15[ i ], silk_DIV32_16( silk_LSHIFT( (opus_int32)res_Q10[ i ], 14 ), W_tmp_Q9 ) );
96 pNLSF_Q15[ i ] = (opus_int16)silk_LIMIT( NLSF_Q15_tmp, 0, 32767 );
97 }
98
99 /* NLSF stabilization */
100 silk_NLSF_stabilize( pNLSF_Q15, psNLSF_CB->deltaMin_Q15, psNLSF_CB->order );
101 }
102