1/***********************************************************************
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15THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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26***********************************************************************/
27
28#ifdef HAVE_CONFIG_H
29#include "config.h"
30#endif
31
32#include <stdlib.h>
33#include "main_FLP.h"
34#include "tuning_parameters.h"
35
36void silk_find_pitch_lags_FLP(
37    silk_encoder_state_FLP          *psEnc,                             /* I/O  Encoder state FLP                           */
38    silk_encoder_control_FLP        *psEncCtrl,                         /* I/O  Encoder control FLP                         */
39    silk_float                      res[],                              /* O    Residual                                    */
40    const silk_float                x[],                                /* I    Speech signal                               */
41    int                             arch                                /* I    Run-time architecture                       */
42)
43{
44    opus_int   buf_len;
45    silk_float thrhld, res_nrg;
46    const silk_float *x_buf_ptr, *x_buf;
47    silk_float auto_corr[ MAX_FIND_PITCH_LPC_ORDER + 1 ];
48    silk_float A[         MAX_FIND_PITCH_LPC_ORDER ];
49    silk_float refl_coef[ MAX_FIND_PITCH_LPC_ORDER ];
50    silk_float Wsig[      FIND_PITCH_LPC_WIN_MAX ];
51    silk_float *Wsig_ptr;
52
53    /******************************************/
54    /* Set up buffer lengths etc based on Fs  */
55    /******************************************/
56    buf_len = psEnc->sCmn.la_pitch + psEnc->sCmn.frame_length + psEnc->sCmn.ltp_mem_length;
57
58    /* Safety check */
59    silk_assert( buf_len >= psEnc->sCmn.pitch_LPC_win_length );
60
61    x_buf = x - psEnc->sCmn.ltp_mem_length;
62
63    /******************************************/
64    /* Estimate LPC AR coeficients            */
65    /******************************************/
66
67    /* Calculate windowed signal */
68
69    /* First LA_LTP samples */
70    x_buf_ptr = x_buf + buf_len - psEnc->sCmn.pitch_LPC_win_length;
71    Wsig_ptr  = Wsig;
72    silk_apply_sine_window_FLP( Wsig_ptr, x_buf_ptr, 1, psEnc->sCmn.la_pitch );
73
74    /* Middle non-windowed samples */
75    Wsig_ptr  += psEnc->sCmn.la_pitch;
76    x_buf_ptr += psEnc->sCmn.la_pitch;
77    silk_memcpy( Wsig_ptr, x_buf_ptr, ( psEnc->sCmn.pitch_LPC_win_length - ( psEnc->sCmn.la_pitch << 1 ) ) * sizeof( silk_float ) );
78
79    /* Last LA_LTP samples */
80    Wsig_ptr  += psEnc->sCmn.pitch_LPC_win_length - ( psEnc->sCmn.la_pitch << 1 );
81    x_buf_ptr += psEnc->sCmn.pitch_LPC_win_length - ( psEnc->sCmn.la_pitch << 1 );
82    silk_apply_sine_window_FLP( Wsig_ptr, x_buf_ptr, 2, psEnc->sCmn.la_pitch );
83
84    /* Calculate autocorrelation sequence */
85    silk_autocorrelation_FLP( auto_corr, Wsig, psEnc->sCmn.pitch_LPC_win_length, psEnc->sCmn.pitchEstimationLPCOrder + 1 );
86
87    /* Add white noise, as a fraction of the energy */
88    auto_corr[ 0 ] += auto_corr[ 0 ] * FIND_PITCH_WHITE_NOISE_FRACTION + 1;
89
90    /* Calculate the reflection coefficients using Schur */
91    res_nrg = silk_schur_FLP( refl_coef, auto_corr, psEnc->sCmn.pitchEstimationLPCOrder );
92
93    /* Prediction gain */
94    psEncCtrl->predGain = auto_corr[ 0 ] / silk_max_float( res_nrg, 1.0f );
95
96    /* Convert reflection coefficients to prediction coefficients */
97    silk_k2a_FLP( A, refl_coef, psEnc->sCmn.pitchEstimationLPCOrder );
98
99    /* Bandwidth expansion */
100    silk_bwexpander_FLP( A, psEnc->sCmn.pitchEstimationLPCOrder, FIND_PITCH_BANDWIDTH_EXPANSION );
101
102    /*****************************************/
103    /* LPC analysis filtering                */
104    /*****************************************/
105    silk_LPC_analysis_filter_FLP( res, A, x_buf, buf_len, psEnc->sCmn.pitchEstimationLPCOrder );
106
107    if( psEnc->sCmn.indices.signalType != TYPE_NO_VOICE_ACTIVITY && psEnc->sCmn.first_frame_after_reset == 0 ) {
108        /* Threshold for pitch estimator */
109        thrhld  = 0.6f;
110        thrhld -= 0.004f * psEnc->sCmn.pitchEstimationLPCOrder;
111        thrhld -= 0.1f   * psEnc->sCmn.speech_activity_Q8 * ( 1.0f /  256.0f );
112        thrhld -= 0.15f  * (psEnc->sCmn.prevSignalType >> 1);
113        thrhld -= 0.1f   * psEnc->sCmn.input_tilt_Q15 * ( 1.0f / 32768.0f );
114
115        /*****************************************/
116        /* Call Pitch estimator                  */
117        /*****************************************/
118        if( silk_pitch_analysis_core_FLP( res, psEncCtrl->pitchL, &psEnc->sCmn.indices.lagIndex,
119            &psEnc->sCmn.indices.contourIndex, &psEnc->LTPCorr, psEnc->sCmn.prevLag, psEnc->sCmn.pitchEstimationThreshold_Q16 / 65536.0f,
120            thrhld, psEnc->sCmn.fs_kHz, psEnc->sCmn.pitchEstimationComplexity, psEnc->sCmn.nb_subfr, arch ) == 0 )
121        {
122            psEnc->sCmn.indices.signalType = TYPE_VOICED;
123        } else {
124            psEnc->sCmn.indices.signalType = TYPE_UNVOICED;
125        }
126    } else {
127        silk_memset( psEncCtrl->pitchL, 0, sizeof( psEncCtrl->pitchL ) );
128        psEnc->sCmn.indices.lagIndex = 0;
129        psEnc->sCmn.indices.contourIndex = 0;
130        psEnc->LTPCorr = 0;
131    }
132}
133