ref: 541a472ff6a74b8320eed2149799bafbac31f25e
dir: /silk/float/find_pitch_lags_FLP.c/
/***********************************************************************
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***********************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdlib.h>
#include "main_FLP.h"
#include "tuning_parameters.h"
void silk_find_pitch_lags_FLP(
silk_encoder_state_FLP *psEnc, /* I/O Encoder state FLP */
silk_encoder_control_FLP *psEncCtrl, /* I/O Encoder control FLP */
silk_float res[], /* O Residual */
const silk_float x[] /* I Speech signal */
)
{
opus_int buf_len;
silk_float thrhld, res_nrg;
const silk_float *x_buf_ptr, *x_buf;
silk_float auto_corr[ MAX_FIND_PITCH_LPC_ORDER + 1 ];
silk_float A[ MAX_FIND_PITCH_LPC_ORDER ];
silk_float refl_coef[ MAX_FIND_PITCH_LPC_ORDER ];
silk_float Wsig[ FIND_PITCH_LPC_WIN_MAX ];
silk_float *Wsig_ptr;
/******************************************/
/* Set up buffer lengths etc based on Fs */
/******************************************/
buf_len = psEnc->sCmn.la_pitch + psEnc->sCmn.frame_length + psEnc->sCmn.ltp_mem_length;
/* Safety check */
silk_assert( buf_len >= psEnc->sCmn.pitch_LPC_win_length );
x_buf = x - psEnc->sCmn.ltp_mem_length;
/******************************************/
/* Estimate LPC AR coeficients */
/******************************************/
/* Calculate windowed signal */
/* First LA_LTP samples */
x_buf_ptr = x_buf + buf_len - psEnc->sCmn.pitch_LPC_win_length;
Wsig_ptr = Wsig;
silk_apply_sine_window_FLP( Wsig_ptr, x_buf_ptr, 1, psEnc->sCmn.la_pitch );
/* Middle non-windowed samples */
Wsig_ptr += psEnc->sCmn.la_pitch;
x_buf_ptr += psEnc->sCmn.la_pitch;
silk_memcpy( Wsig_ptr, x_buf_ptr, ( psEnc->sCmn.pitch_LPC_win_length - ( psEnc->sCmn.la_pitch << 1 ) ) * sizeof( silk_float ) );
/* Last LA_LTP samples */
Wsig_ptr += psEnc->sCmn.pitch_LPC_win_length - ( psEnc->sCmn.la_pitch << 1 );
x_buf_ptr += psEnc->sCmn.pitch_LPC_win_length - ( psEnc->sCmn.la_pitch << 1 );
silk_apply_sine_window_FLP( Wsig_ptr, x_buf_ptr, 2, psEnc->sCmn.la_pitch );
/* Calculate autocorrelation sequence */
silk_autocorrelation_FLP( auto_corr, Wsig, psEnc->sCmn.pitch_LPC_win_length, psEnc->sCmn.pitchEstimationLPCOrder + 1 );
/* Add white noise, as a fraction of the energy */
auto_corr[ 0 ] += auto_corr[ 0 ] * FIND_PITCH_WHITE_NOISE_FRACTION + 1;
/* Calculate the reflection coefficients using Schur */
res_nrg = silk_schur_FLP( refl_coef, auto_corr, psEnc->sCmn.pitchEstimationLPCOrder );
/* Prediction gain */
psEncCtrl->predGain = auto_corr[ 0 ] / silk_max_float( res_nrg, 1.0f );
/* Convert reflection coefficients to prediction coefficients */
silk_k2a_FLP( A, refl_coef, psEnc->sCmn.pitchEstimationLPCOrder );
/* Bandwidth expansion */
silk_bwexpander_FLP( A, psEnc->sCmn.pitchEstimationLPCOrder, FIND_PITCH_BANDWIDTH_EXPANSION );
/*****************************************/
/* LPC analysis filtering */
/*****************************************/
silk_LPC_analysis_filter_FLP( res, A, x_buf, buf_len, psEnc->sCmn.pitchEstimationLPCOrder );
if( psEnc->sCmn.indices.signalType != TYPE_NO_VOICE_ACTIVITY && psEnc->sCmn.first_frame_after_reset == 0 ) {
/* Threshold for pitch estimator */
thrhld = 0.6f;
thrhld -= 0.004f * psEnc->sCmn.pitchEstimationLPCOrder;
thrhld -= 0.1f * psEnc->sCmn.speech_activity_Q8 * ( 1.0f / 256.0f );
thrhld -= 0.15f * (psEnc->sCmn.prevSignalType >> 1);
thrhld -= 0.1f * psEnc->sCmn.input_tilt_Q15 * ( 1.0f / 32768.0f );
/*****************************************/
/* Call Pitch estimator */
/*****************************************/
if( silk_pitch_analysis_core_FLP( res, psEncCtrl->pitchL, &psEnc->sCmn.indices.lagIndex,
&psEnc->sCmn.indices.contourIndex, &psEnc->LTPCorr, psEnc->sCmn.prevLag, psEnc->sCmn.pitchEstimationThreshold_Q16 / 65536.0f,
thrhld, psEnc->sCmn.fs_kHz, psEnc->sCmn.pitchEstimationComplexity, psEnc->sCmn.nb_subfr ) == 0 )
{
psEnc->sCmn.indices.signalType = TYPE_VOICED;
} else {
psEnc->sCmn.indices.signalType = TYPE_UNVOICED;
}
} else {
silk_memset( psEncCtrl->pitchL, 0, sizeof( psEncCtrl->pitchL ) );
psEnc->sCmn.indices.lagIndex = 0;
psEnc->sCmn.indices.contourIndex = 0;
psEnc->LTPCorr = 0;
}
}