/* Find pitch lags */ void SKP_Silk_find_pitch_lags_FIX( SKP_Silk_encoder_state_FIX *psEnc, /* I/O encoder state */ SKP_Silk_encoder_control_FIX *psEncCtrl, /* I/O encoder control */ SKP_int16 res[], /* O residual */ const SKP_int16 x[] /* I Speech signal */ ) { SKP_Silk_predict_state_FIX *psPredSt = &psEnc->sPred; SKP_int buf_len, i, scale; SKP_int32 thrhld_Q15, res_nrg; const SKP_int16 *x_buf, *x_buf_ptr; SKP_int16 Wsig[ FIND_PITCH_LPC_WIN_MAX ], *Wsig_ptr; SKP_int32 auto_corr[ MAX_FIND_PITCH_LPC_ORDER + 1 ]; SKP_int16 rc_Q15[ MAX_FIND_PITCH_LPC_ORDER ]; SKP_int32 A_Q24[ MAX_FIND_PITCH_LPC_ORDER ]; SKP_int32 FiltState[ MAX_FIND_PITCH_LPC_ORDER ]; SKP_int16 A_Q12[ MAX_FIND_PITCH_LPC_ORDER ]; /******************************************/ /* Setup buffer lengths etc based on Fs */ /******************************************/ buf_len = SKP_ADD_LSHIFT( psEnc->sCmn.la_pitch, psEnc->sCmn.frame_length, 1 ); /* Safty check */ SKP_assert( buf_len >= psPredSt->pitch_LPC_win_length ); x_buf = x - psEnc->sCmn.frame_length; /*************************************/ /* Estimate LPC AR coefficients */ /*************************************/ /* Calculate windowed signal */ /* First LA_LTP samples */ x_buf_ptr = x_buf + buf_len - psPredSt->pitch_LPC_win_length; Wsig_ptr = Wsig; SKP_Silk_apply_sine_window_new( Wsig_ptr, x_buf_ptr, 1, psEnc->sCmn.la_pitch ); /* Middle un - windowed samples */ Wsig_ptr += psEnc->sCmn.la_pitch; x_buf_ptr += psEnc->sCmn.la_pitch; SKP_memcpy( Wsig_ptr, x_buf_ptr, ( psPredSt->pitch_LPC_win_length - SKP_LSHIFT( psEnc->sCmn.la_pitch, 1 ) ) * sizeof( SKP_int16 ) ); /* Last LA_LTP samples */ Wsig_ptr += psPredSt->pitch_LPC_win_length - SKP_LSHIFT( psEnc->sCmn.la_pitch, 1 ); x_buf_ptr += psPredSt->pitch_LPC_win_length - SKP_LSHIFT( psEnc->sCmn.la_pitch, 1 ); SKP_Silk_apply_sine_window_new( Wsig_ptr, x_buf_ptr, 2, psEnc->sCmn.la_pitch ); /* Calculate autocorrelation sequence */ SKP_Silk_autocorr( auto_corr, &scale, Wsig, psPredSt->pitch_LPC_win_length, psEnc->sCmn.pitchEstimationLPCOrder + 1 ); /* Add white noise, as fraction of energy */ auto_corr[ 0 ] = SKP_SMLAWB( auto_corr[ 0 ], auto_corr[ 0 ], SKP_FIX_CONST( FIND_PITCH_WHITE_NOISE_FRACTION, 16 ) ); /* Calculate the reflection coefficients using schur */ res_nrg = SKP_Silk_schur( rc_Q15, auto_corr, psEnc->sCmn.pitchEstimationLPCOrder ); /* Prediction gain */ psEncCtrl->predGain_Q16 = SKP_DIV32_varQ( auto_corr[ 0 ], SKP_max_int( res_nrg, 1 ), 16 ); /* Convert reflection coefficients to prediction coefficients */ SKP_Silk_k2a( A_Q24, rc_Q15, psEnc->sCmn.pitchEstimationLPCOrder ); /* Convert From 32 bit Q24 to 16 bit Q12 coefs */ for( i = 0; i < psEnc->sCmn.pitchEstimationLPCOrder; i++ ) { A_Q12[ i ] = ( SKP_int16 )SKP_SAT16( SKP_RSHIFT( A_Q24[ i ], 12 ) ); } /* Do BWE */ SKP_Silk_bwexpander( A_Q12, psEnc->sCmn.pitchEstimationLPCOrder, SKP_FIX_CONST( FIND_PITCH_BANDWITH_EXPANSION, 16 ) ); /*****************************************/ /* LPC analysis filtering */ /*****************************************/ SKP_memset( FiltState, 0, psEnc->sCmn.pitchEstimationLPCOrder * sizeof( SKP_int32 ) ); /* Not really necessary, but Valgrind will complain otherwise */ SKP_Silk_MA_Prediction( x_buf, A_Q12, FiltState, res, buf_len, psEnc->sCmn.pitchEstimationLPCOrder ); SKP_memset( res, 0, psEnc->sCmn.pitchEstimationLPCOrder * sizeof( SKP_int16 ) ); /* Threshold for pitch estimator */ thrhld_Q15 = SKP_FIX_CONST( 0.45, 15 ); thrhld_Q15 = SKP_SMLABB( thrhld_Q15, SKP_FIX_CONST( -0.004, 15 ), psEnc->sCmn.pitchEstimationLPCOrder ); thrhld_Q15 = SKP_SMLABB( thrhld_Q15, SKP_FIX_CONST( -0.1, 7 ), psEnc->speech_activity_Q8 ); thrhld_Q15 = SKP_SMLABB( thrhld_Q15, SKP_FIX_CONST( 0.15, 15 ), psEnc->sCmn.prev_sigtype ); thrhld_Q15 = SKP_SMLAWB( thrhld_Q15, SKP_FIX_CONST( -0.1, 16 ), psEncCtrl->input_tilt_Q15 ); thrhld_Q15 = SKP_SAT16( thrhld_Q15 ); /*****************************************/ /* Call pitch estimator */ /*****************************************/ psEncCtrl->sCmn.sigtype = SKP_Silk_pitch_analysis_core( res, psEncCtrl->sCmn.pitchL, &psEncCtrl->sCmn.lagIndex, &psEncCtrl->sCmn.contourIndex, &psEnc->LTPCorr_Q15, psEnc->sCmn.prevLag, psEnc->sCmn.pitchEstimationThreshold_Q16, ( SKP_int16 )thrhld_Q15, psEnc->sCmn.fs_kHz, psEnc->sCmn.pitchEstimationComplexity, SKP_FALSE ); }
/* Find pitch lags */ void SKP_Silk_find_pitch_lags_FIX( SKP_Silk_encoder_state_FIX *psEnc, /* I/O encoder state */ SKP_Silk_encoder_control_FIX *psEncCtrl, /* I/O encoder control */ SKP_int16 res[], /* O residual */ const SKP_int16 x[] /* I Speech signal */ ) { SKP_Silk_predict_state_FIX *psPredSt = &psEnc->sPred; SKP_int buf_len, i; SKP_int32 scale; SKP_int32 thrhld_Q15; const SKP_int16 *x_buf, *x_buf_ptr; SKP_int16 Wsig[ FIND_PITCH_LPC_WIN_MAX ], *Wsig_ptr; SKP_int32 auto_corr[ FIND_PITCH_LPC_ORDER_MAX + 1 ]; SKP_int16 rc_Q15[ FIND_PITCH_LPC_ORDER_MAX ]; SKP_int32 A_Q24[ FIND_PITCH_LPC_ORDER_MAX ]; SKP_int32 FiltState[ FIND_PITCH_LPC_ORDER_MAX ]; SKP_int16 A_Q12[ FIND_PITCH_LPC_ORDER_MAX ]; /******************************************/ /* Setup buffer lengths etc based of Fs. */ /******************************************/ buf_len = SKP_ADD_LSHIFT( psEnc->sCmn.la_pitch, psEnc->sCmn.frame_length, 1 ); /* Safty check */ SKP_assert( buf_len >= psPredSt->pitch_LPC_win_length ); x_buf = x - psEnc->sCmn.frame_length; /*************************************/ /* Estimate LPC AR coeficients */ /*************************************/ /* Calculate windowed signal */ /* First LA_LTP samples */ x_buf_ptr = x_buf + buf_len - psPredSt->pitch_LPC_win_length; Wsig_ptr = Wsig; SKP_Silk_apply_sine_window( Wsig_ptr, x_buf_ptr, 1, psEnc->sCmn.la_pitch ); /* Middle un - windowed samples */ Wsig_ptr += psEnc->sCmn.la_pitch; x_buf_ptr += psEnc->sCmn.la_pitch; SKP_memcpy( Wsig_ptr, x_buf_ptr, ( psPredSt->pitch_LPC_win_length - SKP_LSHIFT( psEnc->sCmn.la_pitch, 1 ) ) * sizeof( SKP_int16 ) ); /* Last LA_LTP samples */ Wsig_ptr += psPredSt->pitch_LPC_win_length - SKP_LSHIFT( psEnc->sCmn.la_pitch, 1 ); x_buf_ptr += psPredSt->pitch_LPC_win_length - SKP_LSHIFT( psEnc->sCmn.la_pitch, 1 ); SKP_Silk_apply_sine_window( Wsig_ptr, x_buf_ptr, 2, psEnc->sCmn.la_pitch ); /* Calculate autocorrelation sequence */ SKP_Silk_autocorr( auto_corr, &scale, Wsig, psPredSt->pitch_LPC_win_length, psEnc->sCmn.pitchEstimationLPCOrder + 1 ); /* add white noise, as fraction of energy */ auto_corr[ 0 ] = SKP_SMLAWB( auto_corr[ 0 ], auto_corr[ 0 ], FIND_PITCH_WHITE_NOISE_FRACTION_Q16 ); /* calculate the reflection coefficients using schur */ SKP_Silk_schur( rc_Q15, auto_corr, psEnc->sCmn.pitchEstimationLPCOrder ); /* convert reflection coefficients to prediction coefficients */ SKP_Silk_k2a( A_Q24, rc_Q15, psEnc->sCmn.pitchEstimationLPCOrder ); /* Convert From 32 bit Q24 to 16 bit Q12 coefs */ for( i = 0; i < psEnc->sCmn.pitchEstimationLPCOrder; i++ ) { A_Q12[ i ] = ( SKP_int16 )SKP_SAT16( SKP_RSHIFT( A_Q24[ i ], 12 ) ); } /* Do BWE */ SKP_Silk_bwexpander( A_Q12, psEnc->sCmn.pitchEstimationLPCOrder, FIND_PITCH_BANDWITH_EXPANSION_Q16 ); /*****************************************/ /* LPC analysis filtering */ /*****************************************/ SKP_memset( FiltState, 0, psEnc->sCmn.pitchEstimationLPCOrder * sizeof( SKP_int16 ) ); SKP_Silk_MA_Prediction( x_buf, A_Q12, FiltState, res, buf_len, psEnc->sCmn.pitchEstimationLPCOrder ); SKP_memset( res, 0, psEnc->sCmn.pitchEstimationLPCOrder * sizeof( SKP_int16 ) ); /* Threshold for pitch estimator */ thrhld_Q15 = ( 1 << 14 ); // 0.5f in Q15 thrhld_Q15 = SKP_SMLABB( thrhld_Q15, -131, psEnc->sCmn.pitchEstimationLPCOrder ); thrhld_Q15 = SKP_SMLABB( thrhld_Q15, -13, ( SKP_int16 )SKP_Silk_SQRT_APPROX( SKP_LSHIFT( ( SKP_int32 )psEnc->speech_activity_Q8, 8 ) ) ); thrhld_Q15 = SKP_SMLABB( thrhld_Q15, 4587, psEnc->sCmn.prev_sigtype ); thrhld_Q15 = SKP_MLA( thrhld_Q15, -31, SKP_RSHIFT( psEncCtrl->input_tilt_Q15, 8 ) ); thrhld_Q15 = SKP_SAT16( thrhld_Q15 ); /*****************************************/ /* Call Pitch estimator */ /*****************************************/ psEncCtrl->sCmn.sigtype = SKP_Silk_pitch_analysis_core( res, psEncCtrl->sCmn.pitchL, &psEncCtrl->sCmn.lagIndex, &psEncCtrl->sCmn.contourIndex, &psEnc->LTPCorr_Q15, psEnc->sCmn.prevLag, psEnc->pitchEstimationThreshold_Q16, ( SKP_int16 )thrhld_Q15, psEnc->sCmn.fs_kHz, psEnc->sCmn.pitchEstimationComplexity ); }