1/***********************************************************************
2Copyright (c) 2006-2011, Skype Limited. All rights reserved.
3Redistribution and use in source and binary forms, with or without
4modification, are permitted provided that the following conditions
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6- Redistributions of source code must retain the above copyright notice,
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8- Redistributions in binary form must reproduce the above copyright
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14permission.
15THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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26***********************************************************************/
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 */
35void 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_int32   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_SMLAWB( silk_RSHIFT( pNLSFW_QW[ i ], 1 ), (opus_int32)pNLSFW0_temp_QW[ i ], i_sqr_Q15 );
83            silk_assert( pNLSFW_QW[ i ] >= 1 );
84        }
85    }
86
87    silk_NLSF_encode( psEncC->indices.NLSFIndices, pNLSF_Q15, psEncC->psNLSF_CB, pNLSFW_QW,
88        NLSF_mu_Q20, psEncC->NLSF_MSVQ_Survivors, psEncC->indices.signalType );
89
90    /* Convert quantized NLSFs back to LPC coefficients */
91    silk_NLSF2A( PredCoef_Q12[ 1 ], pNLSF_Q15, psEncC->predictLPCOrder );
92
93    if( doInterpolate ) {
94        /* Calculate the interpolated, quantized LSF vector for the first half */
95        silk_interpolate( pNLSF0_temp_Q15, prev_NLSFq_Q15, pNLSF_Q15,
96            psEncC->indices.NLSFInterpCoef_Q2, psEncC->predictLPCOrder );
97
98        /* Convert back to LPC coefficients */
99        silk_NLSF2A( PredCoef_Q12[ 0 ], pNLSF0_temp_Q15, psEncC->predictLPCOrder );
100
101    } else {
102        /* Copy LPC coefficients for first half from second half */
103        silk_memcpy( PredCoef_Q12[ 0 ], PredCoef_Q12[ 1 ], psEncC->predictLPCOrder * sizeof( opus_int16 ) );
104    }
105}
106