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15 BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
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26 ***********************************************************************/
27
28 #include "SKP_Silk_main_FIX.h"
29
30 /* Find pitch lags */
SKP_Silk_find_pitch_lags_FIX(SKP_Silk_encoder_state_FIX * psEnc,SKP_Silk_encoder_control_FIX * psEncCtrl,SKP_int16 res[],const SKP_int16 x[])31 void SKP_Silk_find_pitch_lags_FIX(
32 SKP_Silk_encoder_state_FIX *psEnc, /* I/O encoder state */
33 SKP_Silk_encoder_control_FIX *psEncCtrl, /* I/O encoder control */
34 SKP_int16 res[], /* O residual */
35 const SKP_int16 x[] /* I Speech signal */
36 )
37 {
38 SKP_Silk_predict_state_FIX *psPredSt = &psEnc->sPred;
39 SKP_int buf_len, i, scale;
40 SKP_int32 thrhld_Q15;
41 const SKP_int16 *x_buf, *x_buf_ptr;
42 SKP_int16 Wsig[ FIND_PITCH_LPC_WIN_MAX ], *Wsig_ptr;
43 SKP_int32 auto_corr[ FIND_PITCH_LPC_ORDER_MAX + 1 ];
44 SKP_int16 rc_Q15[ FIND_PITCH_LPC_ORDER_MAX ];
45 SKP_int32 A_Q24[ FIND_PITCH_LPC_ORDER_MAX ];
46 SKP_int32 FiltState[ FIND_PITCH_LPC_ORDER_MAX ];
47 SKP_int16 A_Q12[ FIND_PITCH_LPC_ORDER_MAX ];
48
49 /******************************************/
50 /* Setup buffer lengths etc based of Fs. */
51 /******************************************/
52 buf_len = SKP_ADD_LSHIFT( psEnc->sCmn.la_pitch, psEnc->sCmn.frame_length, 1 );
53
54 /* Safty check */
55 SKP_assert( buf_len >= psPredSt->pitch_LPC_win_length );
56
57 x_buf = x - psEnc->sCmn.frame_length;
58
59 /*************************************/
60 /* Estimate LPC AR coeficients */
61 /*************************************/
62
63 /* Calculate windowed signal */
64
65 /* First LA_LTP samples */
66 x_buf_ptr = x_buf + buf_len - psPredSt->pitch_LPC_win_length;
67 Wsig_ptr = Wsig;
68 SKP_Silk_apply_sine_window( Wsig_ptr, x_buf_ptr, 1, psEnc->sCmn.la_pitch );
69
70 /* Middle un - windowed samples */
71 Wsig_ptr += psEnc->sCmn.la_pitch;
72 x_buf_ptr += psEnc->sCmn.la_pitch;
73 SKP_memcpy( Wsig_ptr, x_buf_ptr, ( psPredSt->pitch_LPC_win_length - SKP_LSHIFT( psEnc->sCmn.la_pitch, 1 ) ) * sizeof( SKP_int16 ) );
74
75 /* Last LA_LTP samples */
76 Wsig_ptr += psPredSt->pitch_LPC_win_length - SKP_LSHIFT( psEnc->sCmn.la_pitch, 1 );
77 x_buf_ptr += psPredSt->pitch_LPC_win_length - SKP_LSHIFT( psEnc->sCmn.la_pitch, 1 );
78 SKP_Silk_apply_sine_window( Wsig_ptr, x_buf_ptr, 2, psEnc->sCmn.la_pitch );
79
80 /* Calculate autocorrelation sequence */
81 SKP_Silk_autocorr( auto_corr, &scale, Wsig, psPredSt->pitch_LPC_win_length, psEnc->sCmn.pitchEstimationLPCOrder + 1 );
82
83 /* add white noise, as fraction of energy */
84 auto_corr[ 0 ] = SKP_SMLAWB( auto_corr[ 0 ], auto_corr[ 0 ], FIND_PITCH_WHITE_NOISE_FRACTION_Q16 );
85
86 /* calculate the reflection coefficients using schur */
87 SKP_Silk_schur( rc_Q15, auto_corr, psEnc->sCmn.pitchEstimationLPCOrder );
88
89 /* convert reflection coefficients to prediction coefficients */
90 SKP_Silk_k2a( A_Q24, rc_Q15, psEnc->sCmn.pitchEstimationLPCOrder );
91
92 /* Convert From 32 bit Q24 to 16 bit Q12 coefs */
93 for( i = 0; i < psEnc->sCmn.pitchEstimationLPCOrder; i++ ) {
94 A_Q12[ i ] = ( SKP_int16 )SKP_SAT16( SKP_RSHIFT( A_Q24[ i ], 12 ) );
95 }
96
97 /* Do BWE */
98 SKP_Silk_bwexpander( A_Q12, psEnc->sCmn.pitchEstimationLPCOrder, FIND_PITCH_BANDWITH_EXPANSION_Q16 );
99
100 /*****************************************/
101 /* LPC analysis filtering */
102 /*****************************************/
103 SKP_memset( FiltState, 0, psEnc->sCmn.pitchEstimationLPCOrder * sizeof(SKP_int32) ); /* Not really nessacary, but Valgrind will complain otherwise */
104 SKP_Silk_MA_Prediction( x_buf, A_Q12, FiltState, res, buf_len, psEnc->sCmn.pitchEstimationLPCOrder );
105 SKP_memset( res, 0, psEnc->sCmn.pitchEstimationLPCOrder * sizeof( SKP_int16 ) );
106
107 /* Threshold for pitch estimator */
108 thrhld_Q15 = ( 1 << 14 ); // 0.5f in Q15
109 thrhld_Q15 = SKP_SMLABB( thrhld_Q15, -131, psEnc->sCmn.pitchEstimationLPCOrder );
110 thrhld_Q15 = SKP_SMLABB( thrhld_Q15, -13, ( SKP_int16 )SKP_Silk_SQRT_APPROX( SKP_LSHIFT( ( SKP_int32 )psEnc->speech_activity_Q8, 8 ) ) );
111 thrhld_Q15 = SKP_SMLABB( thrhld_Q15, 4587, psEnc->sCmn.prev_sigtype );
112 thrhld_Q15 = SKP_MLA( thrhld_Q15, -31, SKP_RSHIFT( psEncCtrl->input_tilt_Q15, 8 ) );
113 thrhld_Q15 = SKP_SAT16( thrhld_Q15 );
114
115 /*****************************************/
116 /* Call Pitch estimator */
117 /*****************************************/
118 psEncCtrl->sCmn.sigtype = SKP_Silk_pitch_analysis_core( res, psEncCtrl->sCmn.pitchL, &psEncCtrl->sCmn.lagIndex,
119 &psEncCtrl->sCmn.contourIndex, &psEnc->LTPCorr_Q15, psEnc->sCmn.prevLag, psEnc->pitchEstimationThreshold_Q16,
120 ( SKP_int16 )thrhld_Q15, psEnc->sCmn.fs_kHz, psEnc->sCmn.pitchEstimationComplexity );
121 }
122