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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 
silk_find_pitch_lags_FLP(silk_encoder_state_FLP * psEnc,silk_encoder_control_FLP * psEncCtrl,silk_float res[],const silk_float x[],int arch)36 void 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