void SKP_Silk_noise_shape_analysis_FIX( SKP_Silk_encoder_state_FIX *psEnc, /* I/O Encoder state FIX */ SKP_Silk_encoder_control_FIX *psEncCtrl, /* I/O Encoder control FIX */ const SKP_int16 *pitch_res, /* I LPC residual from pitch analysis */ const SKP_int16 *x /* I Input signal [ frame_length + la_shape ] */ ) { SKP_Silk_shape_state_FIX *psShapeSt = &psEnc->sShape; SKP_int k, i, nSamples, Qnrg, b_Q14, warping_Q16, scale = 0; SKP_int32 SNR_adj_dB_Q7, HarmBoost_Q16, HarmShapeGain_Q16, Tilt_Q16, tmp32; SKP_int32 nrg, pre_nrg_Q30, log_energy_Q7, log_energy_prev_Q7, energy_variation_Q7; SKP_int32 delta_Q16, BWExp1_Q16, BWExp2_Q16, gain_mult_Q16, gain_add_Q16, strength_Q16, b_Q8; SKP_int32 auto_corr[ MAX_SHAPE_LPC_ORDER + 1 ]; SKP_int32 refl_coef_Q16[ MAX_SHAPE_LPC_ORDER ]; SKP_int32 AR1_Q24[ MAX_SHAPE_LPC_ORDER ]; SKP_int32 AR2_Q24[ MAX_SHAPE_LPC_ORDER ]; SKP_int16 x_windowed[ SHAPE_LPC_WIN_MAX ]; SKP_int32 sqrt_nrg[ MAX_NB_SUBFR ], Qnrg_vec[ MAX_NB_SUBFR ]; const SKP_int16 *x_ptr, *pitch_res_ptr; /* Point to start of first LPC analysis block */ x_ptr = x - psEnc->sCmn.la_shape; /****************/ /* CONTROL SNR */ /****************/ /* Reduce SNR_dB values if recent bitstream has exceeded TargetRate */ psEncCtrl->current_SNR_dB_Q7 = psEnc->SNR_dB_Q7 - SKP_SMULBB( psEnc->BufferedInChannel_ms, SKP_FIX_CONST( 0.1, 7 ) ); /* Reduce SNR_dB because of any inband FEC used */ psEncCtrl->current_SNR_dB_Q7 -= psEnc->inBandFEC_SNR_comp_Q7; /****************/ /* GAIN CONTROL */ /****************/ /* Input quality is the average of the quality in the lowest two VAD bands */ psEncCtrl->input_quality_Q14 = ( SKP_int )SKP_RSHIFT( ( SKP_int32 )psEnc->sCmn.input_quality_bands_Q15[ 0 ] + psEnc->sCmn.input_quality_bands_Q15[ 1 ], 2 ); /* Coding quality level, between 0.0_Q0 and 1.0_Q0, but in Q14 */ psEncCtrl->coding_quality_Q14 = SKP_RSHIFT( SKP_Silk_sigm_Q15( SKP_RSHIFT_ROUND( psEncCtrl->current_SNR_dB_Q7 - SKP_FIX_CONST( 18.0, 7 ), 4 ) ), 1 ); /* Reduce coding SNR during low speech activity */ SNR_adj_dB_Q7 = psEncCtrl->current_SNR_dB_Q7; if( psEnc->sCmn.useCBR == 0 ) { b_Q8 = SKP_FIX_CONST( 1.0, 8 ) - psEnc->sCmn.speech_activity_Q8; b_Q8 = SKP_SMULWB( SKP_LSHIFT( b_Q8, 8 ), b_Q8 ); SNR_adj_dB_Q7 = SKP_SMLAWB( SNR_adj_dB_Q7, SKP_SMULBB( SKP_FIX_CONST( -BG_SNR_DECR_dB, 7 ) >> ( 4 + 1 ), b_Q8 ), // Q11 SKP_SMULWB( SKP_FIX_CONST( 1.0, 14 ) + psEncCtrl->input_quality_Q14, psEncCtrl->coding_quality_Q14 ) ); // Q12 }
/* non-warped frequency scale. (So that it can be implemented with a minimum-phase monic filter.) */ SKP_INLINE SKP_int32 warped_gain( // gain in Q16 const SKP_int32 *coefs_Q24, SKP_int lambda_Q16, SKP_int order ) { SKP_int i; SKP_int32 gain_Q24; lambda_Q16 = -lambda_Q16; gain_Q24 = coefs_Q24[ order - 1 ]; for( i = order - 2; i >= 0; i-- ) { gain_Q24 = SKP_SMLAWB( coefs_Q24[ i ], gain_Q24, lambda_Q16 ); } gain_Q24 = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 24 ), gain_Q24, -lambda_Q16 ); return SKP_INVERSE32_varQ( gain_Q24, 40 ); }
/* amplitude of monic warped coefficients by using bandwidth expansion on the true coefficients */ SKP_INLINE void limit_warped_coefs( SKP_int32 *coefs_syn_Q24, SKP_int32 *coefs_ana_Q24, SKP_int lambda_Q16, SKP_int32 limit_Q24, SKP_int order ) { SKP_int i, iter, ind = 0; SKP_int32 tmp, maxabs_Q24, chirp_Q16, gain_syn_Q16, gain_ana_Q16; SKP_int32 nom_Q16, den_Q24; /* Convert to monic coefficients */ lambda_Q16 = -lambda_Q16; for( i = order - 1; i > 0; i-- ) { coefs_syn_Q24[ i - 1 ] = SKP_SMLAWB( coefs_syn_Q24[ i - 1 ], coefs_syn_Q24[ i ], lambda_Q16 ); coefs_ana_Q24[ i - 1 ] = SKP_SMLAWB( coefs_ana_Q24[ i - 1 ], coefs_ana_Q24[ i ], lambda_Q16 ); } lambda_Q16 = -lambda_Q16; nom_Q16 = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 16 ), -lambda_Q16, lambda_Q16 ); den_Q24 = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 24 ), coefs_syn_Q24[ 0 ], lambda_Q16 ); gain_syn_Q16 = SKP_DIV32_varQ( nom_Q16, den_Q24, 24 ); den_Q24 = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 24 ), coefs_ana_Q24[ 0 ], lambda_Q16 ); gain_ana_Q16 = SKP_DIV32_varQ( nom_Q16, den_Q24, 24 ); for( i = 0; i < order; i++ ) { coefs_syn_Q24[ i ] = SKP_SMULWW( gain_syn_Q16, coefs_syn_Q24[ i ] ); coefs_ana_Q24[ i ] = SKP_SMULWW( gain_ana_Q16, coefs_ana_Q24[ i ] ); } for( iter = 0; iter < 10; iter++ ) { /* Find maximum absolute value */ maxabs_Q24 = -1; for( i = 0; i < order; i++ ) { tmp = SKP_max( SKP_abs_int32( coefs_syn_Q24[ i ] ), SKP_abs_int32( coefs_ana_Q24[ i ] ) ); if( tmp > maxabs_Q24 ) { maxabs_Q24 = tmp; ind = i; } } if( maxabs_Q24 <= limit_Q24 ) { /* Coefficients are within range - done */ return; } /* Convert back to true warped coefficients */ for( i = 1; i < order; i++ ) { coefs_syn_Q24[ i - 1 ] = SKP_SMLAWB( coefs_syn_Q24[ i - 1 ], coefs_syn_Q24[ i ], lambda_Q16 ); coefs_ana_Q24[ i - 1 ] = SKP_SMLAWB( coefs_ana_Q24[ i - 1 ], coefs_ana_Q24[ i ], lambda_Q16 ); } gain_syn_Q16 = SKP_INVERSE32_varQ( gain_syn_Q16, 32 ); gain_ana_Q16 = SKP_INVERSE32_varQ( gain_ana_Q16, 32 ); for( i = 0; i < order; i++ ) { coefs_syn_Q24[ i ] = SKP_SMULWW( gain_syn_Q16, coefs_syn_Q24[ i ] ); coefs_ana_Q24[ i ] = SKP_SMULWW( gain_ana_Q16, coefs_ana_Q24[ i ] ); } /* Apply bandwidth expansion */ chirp_Q16 = SKP_FIX_CONST( 0.99, 16 ) - SKP_DIV32_varQ( SKP_SMULWB( maxabs_Q24 - limit_Q24, SKP_SMLABB( SKP_FIX_CONST( 0.8, 10 ), SKP_FIX_CONST( 0.1, 10 ), iter ) ), SKP_MUL( maxabs_Q24, ind + 1 ), 22 ); SKP_Silk_bwexpander_32( coefs_syn_Q24, order, chirp_Q16 ); SKP_Silk_bwexpander_32( coefs_ana_Q24, order, chirp_Q16 ); /* Convert to monic warped coefficients */ lambda_Q16 = -lambda_Q16; for( i = order - 1; i > 0; i-- ) { coefs_syn_Q24[ i - 1 ] = SKP_SMLAWB( coefs_syn_Q24[ i - 1 ], coefs_syn_Q24[ i ], lambda_Q16 ); coefs_ana_Q24[ i - 1 ] = SKP_SMLAWB( coefs_ana_Q24[ i - 1 ], coefs_ana_Q24[ i ], lambda_Q16 ); } lambda_Q16 = -lambda_Q16; nom_Q16 = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 16 ), -lambda_Q16, lambda_Q16 ); den_Q24 = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 24 ), coefs_syn_Q24[ 0 ], lambda_Q16 ); gain_syn_Q16 = SKP_DIV32_varQ( nom_Q16, den_Q24, 24 ); den_Q24 = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 24 ), coefs_ana_Q24[ 0 ], lambda_Q16 ); gain_ana_Q16 = SKP_DIV32_varQ( nom_Q16, den_Q24, 24 ); for( i = 0; i < order; i++ ) { coefs_syn_Q24[ i ] = SKP_SMULWW( gain_syn_Q16, coefs_syn_Q24[ i ] ); coefs_ana_Q24[ i ] = SKP_SMULWW( gain_ana_Q16, coefs_ana_Q24[ i ] ); } } SKP_assert( 0 ); }
/* High-pass filter with cutoff frequency adaptation based on pitch lag statistics */ void SKP_Silk_HP_variable_cutoff_FIX( SKP_Silk_encoder_state_FIX *psEnc, /* I/O Encoder state FIX */ SKP_Silk_encoder_control_FIX *psEncCtrl, /* I/O Encoder control FIX */ SKP_int16 *out, /* O high-pass filtered output signal */ const SKP_int16 *in /* I input signal */ ) { SKP_int quality_Q15; SKP_int32 B_Q28[ 3 ], A_Q28[ 2 ]; SKP_int32 Fc_Q19, r_Q28, r_Q22; SKP_int32 pitch_freq_Hz_Q16, pitch_freq_log_Q7, delta_freq_Q7; /*********************************************/ /* Estimate Low End of Pitch Frequency Range */ /*********************************************/ if( psEnc->sCmn.prev_sigtype == SIG_TYPE_VOICED ) { /* difference, in log domain */ pitch_freq_Hz_Q16 = SKP_DIV32_16( SKP_LSHIFT( SKP_MUL( psEnc->sCmn.fs_kHz, 1000 ), 16 ), psEnc->sCmn.prevLag ); pitch_freq_log_Q7 = SKP_Silk_lin2log( pitch_freq_Hz_Q16 ) - ( 16 << 7 ); //0x70 /* adjustment based on quality */ quality_Q15 = psEncCtrl->input_quality_bands_Q15[ 0 ]; pitch_freq_log_Q7 = SKP_SUB32( pitch_freq_log_Q7, SKP_SMULWB( SKP_SMULWB( SKP_LSHIFT( quality_Q15, 2 ), quality_Q15 ), pitch_freq_log_Q7 - SKP_LOG2_VARIABLE_HP_MIN_FREQ_Q7 ) ); pitch_freq_log_Q7 = SKP_ADD32( pitch_freq_log_Q7, SKP_RSHIFT( SKP_FIX_CONST( 0.6, 15 ) - quality_Q15, 9 ) ); //delta_freq = pitch_freq_log - psEnc->variable_HP_smth1; delta_freq_Q7 = pitch_freq_log_Q7 - SKP_RSHIFT( psEnc->variable_HP_smth1_Q15, 8 ); if( delta_freq_Q7 < 0 ) { /* less smoothing for decreasing pitch frequency, to track something close to the minimum */ delta_freq_Q7 = SKP_MUL( delta_freq_Q7, 3 ); } /* limit delta, to reduce impact of outliers */ delta_freq_Q7 = SKP_LIMIT_32( delta_freq_Q7, -SKP_FIX_CONST( VARIABLE_HP_MAX_DELTA_FREQ, 7 ), SKP_FIX_CONST( VARIABLE_HP_MAX_DELTA_FREQ, 7 ) ); /* update smoother */ psEnc->variable_HP_smth1_Q15 = SKP_SMLAWB( psEnc->variable_HP_smth1_Q15, SKP_MUL( SKP_LSHIFT( psEnc->speech_activity_Q8, 1 ), delta_freq_Q7 ), SKP_FIX_CONST( VARIABLE_HP_SMTH_COEF1, 16 ) ); } /* second smoother */ psEnc->variable_HP_smth2_Q15 = SKP_SMLAWB( psEnc->variable_HP_smth2_Q15, psEnc->variable_HP_smth1_Q15 - psEnc->variable_HP_smth2_Q15, SKP_FIX_CONST( VARIABLE_HP_SMTH_COEF2, 16 ) ); /* convert from log scale to Hertz */ psEncCtrl->pitch_freq_low_Hz = SKP_Silk_log2lin( SKP_RSHIFT( psEnc->variable_HP_smth2_Q15, 8 ) ); /* limit frequency range */ psEncCtrl->pitch_freq_low_Hz = SKP_LIMIT_32( psEncCtrl->pitch_freq_low_Hz, SKP_FIX_CONST( VARIABLE_HP_MIN_FREQ, 0 ), SKP_FIX_CONST( VARIABLE_HP_MAX_FREQ, 0 ) ); /********************************/ /* Compute Filter Coefficients */ /********************************/ /* compute cut-off frequency, in radians */ //Fc_num = (SKP_float)( 0.45f * 2.0f * 3.14159265359 * psEncCtrl->pitch_freq_low_Hz ); //Fc_denom = (SKP_float)( 1e3f * psEnc->sCmn.fs_kHz ); SKP_assert( psEncCtrl->pitch_freq_low_Hz <= SKP_int32_MAX / SKP_RADIANS_CONSTANT_Q19 ); Fc_Q19 = SKP_DIV32_16( SKP_SMULBB( SKP_RADIANS_CONSTANT_Q19, psEncCtrl->pitch_freq_low_Hz ), psEnc->sCmn.fs_kHz ); // range: 3704 - 27787, 11-15 bits SKP_assert( Fc_Q19 >= 3704 ); SKP_assert( Fc_Q19 <= 27787 ); r_Q28 = SKP_FIX_CONST( 1.0, 28 ) - SKP_MUL( SKP_FIX_CONST( 0.92, 9 ), Fc_Q19 ); SKP_assert( r_Q28 >= 255347779 ); SKP_assert( r_Q28 <= 266690872 ); /* b = r * [ 1; -2; 1 ]; */ /* a = [ 1; -2 * r * ( 1 - 0.5 * Fc^2 ); r^2 ]; */ B_Q28[ 0 ] = r_Q28; B_Q28[ 1 ] = SKP_LSHIFT( -r_Q28, 1 ); B_Q28[ 2 ] = r_Q28; // -r * ( 2 - Fc * Fc ); r_Q22 = SKP_RSHIFT( r_Q28, 6 ); A_Q28[ 0 ] = SKP_SMULWW( r_Q22, SKP_SMULWW( Fc_Q19, Fc_Q19 ) - SKP_FIX_CONST( 2.0, 22 ) ); A_Q28[ 1 ] = SKP_SMULWW( r_Q22, r_Q22 ); /********************************/ /* High-Pass Filter */ /********************************/ SKP_Silk_biquad_alt( in, B_Q28, A_Q28, psEnc->sCmn.In_HP_State, out, psEnc->sCmn.frame_length ); }
/* 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 ); }
SKP_INLINE void SKP_Silk_LDL_factorize_FIX( SKP_int32 *A, /* I Pointer to Symetric Square Matrix */ SKP_int M, /* I Size of Matrix */ SKP_int32 *L_Q16, /* I/O Pointer to Square Upper triangular Matrix */ inv_D_t *inv_D /* I/O Pointer to vector holding inverted diagonal elements of D */ ) { SKP_int i, j, k, status, loop_count; const SKP_int32 *ptr1, *ptr2; SKP_int32 diag_min_value, tmp_32, err; SKP_int32 v_Q0[ MAX_MATRIX_SIZE ], D_Q0[ MAX_MATRIX_SIZE ]; SKP_int32 one_div_diag_Q36, one_div_diag_Q40, one_div_diag_Q48; SKP_assert( M <= MAX_MATRIX_SIZE ); status = 1; diag_min_value = SKP_max_32( SKP_SMMUL( SKP_ADD_SAT32( A[ 0 ], A[ SKP_SMULBB( M, M ) - 1 ] ), SKP_FIX_CONST( FIND_LTP_COND_FAC, 31 ) ), 1 << 9 ); for( loop_count = 0; loop_count < M && status == 1; loop_count++ ) { status = 0; for( j = 0; j < M; j++ ) { ptr1 = matrix_adr( L_Q16, j, 0, M ); tmp_32 = 0; for( i = 0; i < j; i++ ) { v_Q0[ i ] = SKP_SMULWW( D_Q0[ i ], ptr1[ i ] ); /* Q0 */ tmp_32 = SKP_SMLAWW( tmp_32, v_Q0[ i ], ptr1[ i ] ); /* Q0 */ } tmp_32 = SKP_SUB32( matrix_ptr( A, j, j, M ), tmp_32 ); if( tmp_32 < diag_min_value ) { tmp_32 = SKP_SUB32( SKP_SMULBB( loop_count + 1, diag_min_value ), tmp_32 ); /* Matrix not positive semi-definite, or ill conditioned */ for( i = 0; i < M; i++ ) { matrix_ptr( A, i, i, M ) = SKP_ADD32( matrix_ptr( A, i, i, M ), tmp_32 ); } status = 1; break; } D_Q0[ j ] = tmp_32; /* always < max(Correlation) */ /* two-step division */ one_div_diag_Q36 = SKP_INVERSE32_varQ( tmp_32, 36 ); /* Q36 */ one_div_diag_Q40 = SKP_LSHIFT( one_div_diag_Q36, 4 ); /* Q40 */ err = SKP_SUB32( 1 << 24, SKP_SMULWW( tmp_32, one_div_diag_Q40 ) ); /* Q24 */ one_div_diag_Q48 = SKP_SMULWW( err, one_div_diag_Q40 ); /* Q48 */ /* Save 1/Ds */ inv_D[ j ].Q36_part = one_div_diag_Q36; inv_D[ j ].Q48_part = one_div_diag_Q48; matrix_ptr( L_Q16, j, j, M ) = 65536; /* 1.0 in Q16 */ ptr1 = matrix_adr( A, j, 0, M ); ptr2 = matrix_adr( L_Q16, j + 1, 0, M ); for( i = j + 1; i < M; i++ ) { tmp_32 = 0; for( k = 0; k < j; k++ ) { tmp_32 = SKP_SMLAWW( tmp_32, v_Q0[ k ], ptr2[ k ] ); /* Q0 */ } tmp_32 = SKP_SUB32( ptr1[ i ], tmp_32 ); /* always < max(Correlation) */ /* tmp_32 / D_Q0[j] : Divide to Q16 */ matrix_ptr( L_Q16, i, j, M ) = SKP_ADD32( SKP_SMMUL( tmp_32, one_div_diag_Q48 ), SKP_RSHIFT( SKP_SMULWW( tmp_32, one_div_diag_Q36 ), 4 ) ); /* go to next column */ ptr2 += M; } } } SKP_assert( status == 0 ); }
/* Convert to monic warped prediction coefficients and limit absolute values */ limit_warped_coefs( AR2_Q24, AR1_Q24, warping_Q16, SKP_FIX_CONST( 3.999, 24 ), psEnc->sCmn.shapingLPCOrder ); /* Convert from Q24 to Q13 and store in int16 */ for( i = 0; i < psEnc->sCmn.shapingLPCOrder; i++ ) { psEncCtrl->AR1_Q13[ k * MAX_SHAPE_LPC_ORDER + i ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( AR1_Q24[ i ], 11 ) ); psEncCtrl->AR2_Q13[ k * MAX_SHAPE_LPC_ORDER + i ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( AR2_Q24[ i ], 11 ) ); } } /*****************/ /* Gain tweaking */ /*****************/ /* Increase gains during low speech activity and put lower limit on gains */ gain_mult_Q16 = SKP_Silk_log2lin( -SKP_SMLAWB( -SKP_FIX_CONST( 16.0, 7 ), SNR_adj_dB_Q7, SKP_FIX_CONST( 0.16, 16 ) ) ); gain_add_Q16 = SKP_Silk_log2lin( SKP_SMLAWB( SKP_FIX_CONST( 16.0, 7 ), SKP_FIX_CONST( NOISE_FLOOR_dB, 7 ), SKP_FIX_CONST( 0.16, 16 ) ) ); tmp32 = SKP_Silk_log2lin( SKP_SMLAWB( SKP_FIX_CONST( 16.0, 7 ), SKP_FIX_CONST( RELATIVE_MIN_GAIN_dB, 7 ), SKP_FIX_CONST( 0.16, 16 ) ) ); tmp32 = SKP_SMULWW( psEnc->avgGain_Q16, tmp32 ); gain_add_Q16 = SKP_ADD_SAT32( gain_add_Q16, tmp32 ); SKP_assert( gain_mult_Q16 >= 0 ); for( k = 0; k < NB_SUBFR; k++ ) { psEncCtrl->Gains_Q16[ k ] = SKP_SMULWW( psEncCtrl->Gains_Q16[ k ], gain_mult_Q16 ); if( psEncCtrl->Gains_Q16[ k ] < 0 ) { psEncCtrl->Gains_Q16[ k ] = SKP_int32_MAX; } } for( k = 0; k < NB_SUBFR; k++ ) { psEncCtrl->Gains_Q16[ k ] = SKP_ADD_POS_SAT32( psEncCtrl->Gains_Q16[ k ], gain_add_Q16 );
void SKP_Silk_noise_shape_analysis_FIX( SKP_Silk_encoder_state_FIX *psEnc, /* I/O Encoder state FIX */ SKP_Silk_encoder_control_FIX *psEncCtrl, /* I/O Encoder control FIX */ const SKP_int16 *pitch_res, /* I LPC residual from pitch analysis */ const SKP_int16 *x /* I Input signal [ frame_length + la_shape ] */ ) { SKP_Silk_shape_state_FIX *psShapeSt = &psEnc->sShape; SKP_int k, i, nSamples, Qnrg, b_Q14, warping_Q16, scale = 0; SKP_int32 SNR_adj_dB_Q7, HarmBoost_Q16, HarmShapeGain_Q16, Tilt_Q16, tmp32; SKP_int32 nrg, pre_nrg_Q30, log_energy_Q7, log_energy_prev_Q7, energy_variation_Q7; SKP_int32 delta_Q16, BWExp1_Q16, BWExp2_Q16, gain_mult_Q16, gain_add_Q16, strength_Q16, b_Q8; SKP_int32 auto_corr[ MAX_SHAPE_LPC_ORDER + 1 ]; SKP_int32 refl_coef_Q16[ MAX_SHAPE_LPC_ORDER ]; SKP_int32 AR1_Q24[ MAX_SHAPE_LPC_ORDER ]; SKP_int32 AR2_Q24[ MAX_SHAPE_LPC_ORDER ]; SKP_int16 x_windowed[ SHAPE_LPC_WIN_MAX ]; const SKP_int16 *x_ptr, *pitch_res_ptr; SKP_int32 sqrt_nrg[ NB_SUBFR ], Qnrg_vec[ NB_SUBFR ]; /* Point to start of first LPC analysis block */ x_ptr = x - psEnc->sCmn.la_shape; /****************/ /* CONTROL SNR */ /****************/ /* Reduce SNR_dB values if recent bitstream has exceeded TargetRate */ psEncCtrl->current_SNR_dB_Q7 = psEnc->SNR_dB_Q7 - SKP_SMULWB( SKP_LSHIFT( ( SKP_int32 )psEnc->BufferedInChannel_ms, 7 ), SKP_FIX_CONST( 0.05, 16 ) ); /* Reduce SNR_dB if inband FEC used */ if( psEnc->speech_activity_Q8 > SKP_FIX_CONST( LBRR_SPEECH_ACTIVITY_THRES, 8 ) ) { psEncCtrl->current_SNR_dB_Q7 -= SKP_RSHIFT( psEnc->inBandFEC_SNR_comp_Q8, 1 ); } /****************/ /* GAIN CONTROL */ /****************/ /* Input quality is the average of the quality in the lowest two VAD bands */ psEncCtrl->input_quality_Q14 = ( SKP_int )SKP_RSHIFT( ( SKP_int32 )psEncCtrl->input_quality_bands_Q15[ 0 ] + psEncCtrl->input_quality_bands_Q15[ 1 ], 2 ); /* Coding quality level, between 0.0_Q0 and 1.0_Q0, but in Q14 */ psEncCtrl->coding_quality_Q14 = SKP_RSHIFT( SKP_Silk_sigm_Q15( SKP_RSHIFT_ROUND( psEncCtrl->current_SNR_dB_Q7 - SKP_FIX_CONST( 18.0, 7 ), 4 ) ), 1 ); /* Reduce coding SNR during low speech activity */ b_Q8 = SKP_FIX_CONST( 1.0, 8 ) - psEnc->speech_activity_Q8; b_Q8 = SKP_SMULWB( SKP_LSHIFT( b_Q8, 8 ), b_Q8 ); SNR_adj_dB_Q7 = SKP_SMLAWB( psEncCtrl->current_SNR_dB_Q7, SKP_SMULBB( SKP_FIX_CONST( -BG_SNR_DECR_dB, 7 ) >> ( 4 + 1 ), b_Q8 ), // Q11 SKP_SMULWB( SKP_FIX_CONST( 1.0, 14 ) + psEncCtrl->input_quality_Q14, psEncCtrl->coding_quality_Q14 ) ); // Q12 if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) { /* Reduce gains for periodic signals */ SNR_adj_dB_Q7 = SKP_SMLAWB( SNR_adj_dB_Q7, SKP_FIX_CONST( HARM_SNR_INCR_dB, 8 ), psEnc->LTPCorr_Q15 ); } else { /* For unvoiced signals and low-quality input, adjust the quality slower than SNR_dB setting */ SNR_adj_dB_Q7 = SKP_SMLAWB( SNR_adj_dB_Q7, SKP_SMLAWB( SKP_FIX_CONST( 6.0, 9 ), -SKP_FIX_CONST( 0.4, 18 ), psEncCtrl->current_SNR_dB_Q7 ), SKP_FIX_CONST( 1.0, 14 ) - psEncCtrl->input_quality_Q14 ); } /*************************/ /* SPARSENESS PROCESSING */ /*************************/ /* Set quantizer offset */ if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) { /* Initally set to 0; may be overruled in process_gains(..) */ psEncCtrl->sCmn.QuantOffsetType = 0; psEncCtrl->sparseness_Q8 = 0; } else { /* Sparseness measure, based on relative fluctuations of energy per 2 milliseconds */ nSamples = SKP_LSHIFT( psEnc->sCmn.fs_kHz, 1 ); energy_variation_Q7 = 0; log_energy_prev_Q7 = 0; pitch_res_ptr = pitch_res; for( k = 0; k < FRAME_LENGTH_MS / 2; k++ ) { SKP_Silk_sum_sqr_shift( &nrg, &scale, pitch_res_ptr, nSamples ); nrg += SKP_RSHIFT( nSamples, scale ); // Q(-scale) log_energy_Q7 = SKP_Silk_lin2log( nrg ); if( k > 0 ) { energy_variation_Q7 += SKP_abs( log_energy_Q7 - log_energy_prev_Q7 ); } log_energy_prev_Q7 = log_energy_Q7; pitch_res_ptr += nSamples; } psEncCtrl->sparseness_Q8 = SKP_RSHIFT( SKP_Silk_sigm_Q15( SKP_SMULWB( energy_variation_Q7 - SKP_FIX_CONST( 5.0, 7 ), SKP_FIX_CONST( 0.1, 16 ) ) ), 7 ); /* Set quantization offset depending on sparseness measure */ if( psEncCtrl->sparseness_Q8 > SKP_FIX_CONST( SPARSENESS_THRESHOLD_QNT_OFFSET, 8 ) ) { psEncCtrl->sCmn.QuantOffsetType = 0; } else { psEncCtrl->sCmn.QuantOffsetType = 1; } /* Increase coding SNR for sparse signals */ SNR_adj_dB_Q7 = SKP_SMLAWB( SNR_adj_dB_Q7, SKP_FIX_CONST( SPARSE_SNR_INCR_dB, 15 ), psEncCtrl->sparseness_Q8 - SKP_FIX_CONST( 0.5, 8 ) ); } /*******************************/ /* Control bandwidth expansion */ /*******************************/ /* More BWE for signals with high prediction gain */ strength_Q16 = SKP_SMULWB( psEncCtrl->predGain_Q16, SKP_FIX_CONST( FIND_PITCH_WHITE_NOISE_FRACTION, 16 ) ); BWExp1_Q16 = BWExp2_Q16 = SKP_DIV32_varQ( SKP_FIX_CONST( BANDWIDTH_EXPANSION, 16 ), SKP_SMLAWW( SKP_FIX_CONST( 1.0, 16 ), strength_Q16, strength_Q16 ), 16 ); delta_Q16 = SKP_SMULWB( SKP_FIX_CONST( 1.0, 16 ) - SKP_SMULBB( 3, psEncCtrl->coding_quality_Q14 ), SKP_FIX_CONST( LOW_RATE_BANDWIDTH_EXPANSION_DELTA, 16 ) ); BWExp1_Q16 = SKP_SUB32( BWExp1_Q16, delta_Q16 ); BWExp2_Q16 = SKP_ADD32( BWExp2_Q16, delta_Q16 ); /* BWExp1 will be applied after BWExp2, so make it relative */ BWExp1_Q16 = SKP_DIV32_16( SKP_LSHIFT( BWExp1_Q16, 14 ), SKP_RSHIFT( BWExp2_Q16, 2 ) ); if( psEnc->sCmn.warping_Q16 > 0 ) { /* Slightly more warping in analysis will move quantization noise up in frequency, where it's better masked */ warping_Q16 = SKP_SMLAWB( psEnc->sCmn.warping_Q16, psEncCtrl->coding_quality_Q14, SKP_FIX_CONST( 0.01, 18 ) ); } else { warping_Q16 = 0; } /********************************************/ /* Compute noise shaping AR coefs and gains */ /********************************************/ for( k = 0; k < NB_SUBFR; k++ ) { /* Apply window: sine slope followed by flat part followed by cosine slope */ SKP_int shift, slope_part, flat_part; flat_part = psEnc->sCmn.fs_kHz * 5; slope_part = SKP_RSHIFT( psEnc->sCmn.shapeWinLength - flat_part, 1 ); SKP_Silk_apply_sine_window_new( x_windowed, x_ptr, 1, slope_part ); shift = slope_part; SKP_memcpy( x_windowed + shift, x_ptr + shift, flat_part * sizeof(SKP_int16) ); shift += flat_part; SKP_Silk_apply_sine_window_new( x_windowed + shift, x_ptr + shift, 2, slope_part ); /* Update pointer: next LPC analysis block */ x_ptr += psEnc->sCmn.subfr_length; if( psEnc->sCmn.warping_Q16 > 0 ) { /* Calculate warped auto correlation */ SKP_Silk_warped_autocorrelation_FIX( auto_corr, &scale, x_windowed, warping_Q16, psEnc->sCmn.shapeWinLength, psEnc->sCmn.shapingLPCOrder ); } else { /* Calculate regular auto correlation */ SKP_Silk_autocorr( auto_corr, &scale, x_windowed, psEnc->sCmn.shapeWinLength, psEnc->sCmn.shapingLPCOrder + 1 ); } /* Add white noise, as a fraction of energy */ auto_corr[0] = SKP_ADD32( auto_corr[0], SKP_max_32( SKP_SMULWB( SKP_RSHIFT( auto_corr[ 0 ], 4 ), SKP_FIX_CONST( SHAPE_WHITE_NOISE_FRACTION, 20 ) ), 1 ) ); /* Calculate the reflection coefficients using schur */ nrg = SKP_Silk_schur64( refl_coef_Q16, auto_corr, psEnc->sCmn.shapingLPCOrder ); SKP_assert( nrg >= 0 ); /* Convert reflection coefficients to prediction coefficients */ SKP_Silk_k2a_Q16( AR2_Q24, refl_coef_Q16, psEnc->sCmn.shapingLPCOrder ); Qnrg = -scale; // range: -12...30 SKP_assert( Qnrg >= -12 ); SKP_assert( Qnrg <= 30 ); /* Make sure that Qnrg is an even number */ if( Qnrg & 1 ) { Qnrg -= 1; nrg >>= 1; } tmp32 = SKP_Silk_SQRT_APPROX( nrg ); Qnrg >>= 1; // range: -6...15 sqrt_nrg[ k ] = tmp32; Qnrg_vec[ k ] = Qnrg; psEncCtrl->Gains_Q16[ k ] = SKP_LSHIFT_SAT32( tmp32, 16 - Qnrg ); if( psEnc->sCmn.warping_Q16 > 0 ) { /* Adjust gain for warping */ gain_mult_Q16 = warped_gain( AR2_Q24, warping_Q16, psEnc->sCmn.shapingLPCOrder ); SKP_assert( psEncCtrl->Gains_Q16[ k ] >= 0 ); psEncCtrl->Gains_Q16[ k ] = SKP_SMULWW( psEncCtrl->Gains_Q16[ k ], gain_mult_Q16 ); if( psEncCtrl->Gains_Q16[ k ] < 0 ) { psEncCtrl->Gains_Q16[ k ] = SKP_int32_MAX; } } /* Bandwidth expansion for synthesis filter shaping */ SKP_Silk_bwexpander_32( AR2_Q24, psEnc->sCmn.shapingLPCOrder, BWExp2_Q16 ); /* Compute noise shaping filter coefficients */ SKP_memcpy( AR1_Q24, AR2_Q24, psEnc->sCmn.shapingLPCOrder * sizeof( SKP_int32 ) ); /* Bandwidth expansion for analysis filter shaping */ SKP_assert( BWExp1_Q16 <= SKP_FIX_CONST( 1.0, 16 ) ); SKP_Silk_bwexpander_32( AR1_Q24, psEnc->sCmn.shapingLPCOrder, BWExp1_Q16 ); /* Ratio of prediction gains, in energy domain */ SKP_Silk_LPC_inverse_pred_gain_Q24( &pre_nrg_Q30, AR2_Q24, psEnc->sCmn.shapingLPCOrder ); SKP_Silk_LPC_inverse_pred_gain_Q24( &nrg, AR1_Q24, psEnc->sCmn.shapingLPCOrder ); //psEncCtrl->GainsPre[ k ] = 1.0f - 0.7f * ( 1.0f - pre_nrg / nrg ) = 0.3f + 0.7f * pre_nrg / nrg; pre_nrg_Q30 = SKP_LSHIFT32( SKP_SMULWB( pre_nrg_Q30, SKP_FIX_CONST( 0.7, 15 ) ), 1 ); psEncCtrl->GainsPre_Q14[ k ] = ( SKP_int ) SKP_FIX_CONST( 0.3, 14 ) + SKP_DIV32_varQ( pre_nrg_Q30, nrg, 14 ); /* Convert to monic warped prediction coefficients and limit absolute values */ limit_warped_coefs( AR2_Q24, AR1_Q24, warping_Q16, SKP_FIX_CONST( 3.999, 24 ), psEnc->sCmn.shapingLPCOrder ); /* Convert from Q24 to Q13 and store in int16 */ for( i = 0; i < psEnc->sCmn.shapingLPCOrder; i++ ) { psEncCtrl->AR1_Q13[ k * MAX_SHAPE_LPC_ORDER + i ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( AR1_Q24[ i ], 11 ) ); psEncCtrl->AR2_Q13[ k * MAX_SHAPE_LPC_ORDER + i ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( AR2_Q24[ i ], 11 ) ); } }
void SKP_Silk_prefilter_FIX( SKP_Silk_encoder_state_FIX *psEnc, /* I/O Encoder state FIX */ const SKP_Silk_encoder_control_FIX *psEncCtrl, /* I Encoder control FIX */ SKP_int16 xw[], /* O Weighted signal */ const SKP_int16 x[] /* I Speech signal */ ) { SKP_Silk_prefilter_state_FIX *P = &psEnc->sPrefilt; SKP_int j, k, lag; SKP_int32 tmp_32; const SKP_int16 *AR1_shp_Q13; const SKP_int16 *px; SKP_int16 *pxw; SKP_int HarmShapeGain_Q12, Tilt_Q14; SKP_int32 HarmShapeFIRPacked_Q12, LF_shp_Q14; SKP_int32 x_filt_Q12[ MAX_FRAME_LENGTH / NB_SUBFR ]; SKP_int16 st_res[ ( MAX_FRAME_LENGTH / NB_SUBFR ) + MAX_SHAPE_LPC_ORDER ]; SKP_int16 B_Q12[ 2 ]; /* Setup pointers */ px = x; pxw = xw; lag = P->lagPrev; for( k = 0; k < NB_SUBFR; k++ ) { /* Update Variables that change per sub frame */ if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) { lag = psEncCtrl->sCmn.pitchL[ k ]; } /* Noise shape parameters */ HarmShapeGain_Q12 = SKP_SMULWB( psEncCtrl->HarmShapeGain_Q14[ k ], 16384 - psEncCtrl->HarmBoost_Q14[ k ] ); SKP_assert( HarmShapeGain_Q12 >= 0 ); HarmShapeFIRPacked_Q12 = SKP_RSHIFT( HarmShapeGain_Q12, 2 ); HarmShapeFIRPacked_Q12 |= SKP_LSHIFT( ( SKP_int32 )SKP_RSHIFT( HarmShapeGain_Q12, 1 ), 16 ); Tilt_Q14 = psEncCtrl->Tilt_Q14[ k ]; LF_shp_Q14 = psEncCtrl->LF_shp_Q14[ k ]; AR1_shp_Q13 = &psEncCtrl->AR1_Q13[ k * MAX_SHAPE_LPC_ORDER ]; /* Short term FIR filtering*/ SKP_Silk_warped_LPC_analysis_filter_FIX( P->sAR_shp, st_res, AR1_shp_Q13, px, psEnc->sCmn.warping_Q16, psEnc->sCmn.subfr_length, psEnc->sCmn.shapingLPCOrder ); /* reduce (mainly) low frequencies during harmonic emphasis */ B_Q12[ 0 ] = SKP_RSHIFT_ROUND( psEncCtrl->GainsPre_Q14[ k ], 2 ); tmp_32 = SKP_SMLABB( SKP_FIX_CONST( INPUT_TILT, 26 ), psEncCtrl->HarmBoost_Q14[ k ], HarmShapeGain_Q12 ); /* Q26 */ tmp_32 = SKP_SMLABB( tmp_32, psEncCtrl->coding_quality_Q14, SKP_FIX_CONST( HIGH_RATE_INPUT_TILT, 12 ) ); /* Q26 */ tmp_32 = SKP_SMULWB( tmp_32, -psEncCtrl->GainsPre_Q14[ k ] ); /* Q24 */ tmp_32 = SKP_RSHIFT_ROUND( tmp_32, 12 ); /* Q12 */ B_Q12[ 1 ]= SKP_SAT16( tmp_32 ); x_filt_Q12[ 0 ] = SKP_SMLABB( SKP_SMULBB( st_res[ 0 ], B_Q12[ 0 ] ), P->sHarmHP, B_Q12[ 1 ] ); for( j = 1; j < psEnc->sCmn.subfr_length; j++ ) { x_filt_Q12[ j ] = SKP_SMLABB( SKP_SMULBB( st_res[ j ], B_Q12[ 0 ] ), st_res[ j - 1 ], B_Q12[ 1 ] ); } P->sHarmHP = st_res[ psEnc->sCmn.subfr_length - 1 ]; SKP_Silk_prefilt_FIX( P, x_filt_Q12, pxw, HarmShapeFIRPacked_Q12, Tilt_Q14, LF_shp_Q14, lag, psEnc->sCmn.subfr_length ); px += psEnc->sCmn.subfr_length; pxw += psEnc->sCmn.subfr_length; } P->lagPrev = psEncCtrl->sCmn.pitchL[ NB_SUBFR - 1 ]; }
/* Processing of gains */ void SKP_Silk_process_gains_FIX( SKP_Silk_encoder_state_FIX *psEnc, /* I/O Encoder state_FIX */ SKP_Silk_encoder_control_FIX *psEncCtrl /* I/O Encoder control_FIX */ ) { SKP_Silk_shape_state_FIX *psShapeSt = &psEnc->sShape; SKP_int k; SKP_int32 s_Q16, InvMaxSqrVal_Q16, gain, gain_squared, ResNrg, ResNrgPart; /* Gain reduction when LTP coding gain is high */ if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) { /*s = -0.5f * SKP_sigmoid( 0.25f * ( psEncCtrl->LTPredCodGain - 12.0f ) ); */ s_Q16 = -SKP_Silk_sigm_Q15( SKP_RSHIFT_ROUND( psEncCtrl->LTPredCodGain_Q7 - (12 << 7), 4 ) ); for( k = 0; k < NB_SUBFR; k++ ) { psEncCtrl->Gains_Q16[ k ] = SKP_SMLAWB( psEncCtrl->Gains_Q16[ k ], psEncCtrl->Gains_Q16[ k ], s_Q16 ); } } /* Limit the quantized signal */ /* 69 = 21.0f + 16/0.33 */ InvMaxSqrVal_Q16 = SKP_DIV32_16( SKP_Silk_log2lin( SKP_SMULWB( (69 << 7) - psEncCtrl->current_SNR_dB_Q7, SKP_FIX_CONST( 0.33, 16 )) ), psEnc->sCmn.subfr_length ); for( k = 0; k < NB_SUBFR; k++ ) { /* Soft limit on ratio residual energy and squared gains */ ResNrg = psEncCtrl->ResNrg[ k ]; ResNrgPart = SKP_SMULWW( ResNrg, InvMaxSqrVal_Q16 ); if( psEncCtrl->ResNrgQ[ k ] > 0 ) { if( psEncCtrl->ResNrgQ[ k ] < 32 ) { ResNrgPart = SKP_RSHIFT_ROUND( ResNrgPart, psEncCtrl->ResNrgQ[ k ] ); } else { ResNrgPart = 0; } } else if( psEncCtrl->ResNrgQ[k] != 0 ) { if( ResNrgPart > SKP_RSHIFT( SKP_int32_MAX, -psEncCtrl->ResNrgQ[ k ] ) ) { ResNrgPart = SKP_int32_MAX; } else { ResNrgPart = SKP_LSHIFT( ResNrgPart, -psEncCtrl->ResNrgQ[ k ] ); } } gain = psEncCtrl->Gains_Q16[ k ]; gain_squared = SKP_ADD_SAT32( ResNrgPart, SKP_SMMUL( gain, gain ) ); if( gain_squared < SKP_int16_MAX ) { /* recalculate with higher precision */ gain_squared = SKP_SMLAWW( SKP_LSHIFT( ResNrgPart, 16 ), gain, gain ); SKP_assert( gain_squared > 0 ); gain = SKP_Silk_SQRT_APPROX( gain_squared ); /* Q8 */ psEncCtrl->Gains_Q16[ k ] = SKP_LSHIFT_SAT32( gain, 8 ); /* Q16 */ } else { gain = SKP_Silk_SQRT_APPROX( gain_squared ); /* Q0 */ psEncCtrl->Gains_Q16[ k ] = SKP_LSHIFT_SAT32( gain, 16 ); /* Q16 */ } } /* Noise shaping quantization */ SKP_Silk_gains_quant( psEncCtrl->sCmn.GainsIndices, psEncCtrl->Gains_Q16, &psShapeSt->LastGainIndex, psEnc->sCmn.nFramesInPayloadBuf ); /* Set quantizer offset for voiced signals. Larger offset when LTP coding gain is low or tilt is high (ie low-pass) */ if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) { if( psEncCtrl->LTPredCodGain_Q7 + SKP_RSHIFT( psEncCtrl->input_tilt_Q15, 8 ) > ( 1 << 7 ) ) { psEncCtrl->sCmn.QuantOffsetType = 0; } else { psEncCtrl->sCmn.QuantOffsetType = 1; } } /* Quantizer boundary adjustment */ if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) { psEncCtrl->Lambda_Q10 = SKP_FIX_CONST( 1.3, 10 ) - SKP_SMULWB( SKP_FIX_CONST( 0.5, 18 ), psEnc->speech_activity_Q8 ) - SKP_SMULWB( SKP_FIX_CONST( 0.3, 12 ), psEncCtrl->input_quality_Q14 ) + SKP_SMULBB( SKP_FIX_CONST( 0.2, 10 ), psEncCtrl->sCmn.QuantOffsetType ) - SKP_SMULWB( SKP_FIX_CONST( 0.1, 12 ), psEncCtrl->coding_quality_Q14 ); } else { psEncCtrl->Lambda_Q10 = SKP_FIX_CONST( 1.3, 10 ) - SKP_SMULWB( SKP_FIX_CONST( 0.5, 18 ), psEnc->speech_activity_Q8 ) - SKP_SMULWB( SKP_FIX_CONST( 0.4, 12 ), psEncCtrl->input_quality_Q14 ) + SKP_SMULBB( SKP_FIX_CONST( 0.4, 10 ), psEncCtrl->sCmn.QuantOffsetType ) - SKP_SMULWB( SKP_FIX_CONST( 0.1, 12 ), psEncCtrl->coding_quality_Q14 ); } SKP_assert( psEncCtrl->Lambda_Q10 >= 0 ); SKP_assert( psEncCtrl->Lambda_Q10 < SKP_FIX_CONST( 2, 10 ) ); }
/* Finds LPC vector from correlations, and converts to NLSF */ void SKP_Silk_find_LPC_FIX( SKP_int NLSF_Q15[], /* O NLSFs */ SKP_int *interpIndex, /* O NLSF interpolation index, only used for NLSF interpolation */ const SKP_int prev_NLSFq_Q15[], /* I previous NLSFs, only used for NLSF interpolation */ const SKP_int useInterpolatedNLSFs, /* I Flag */ const SKP_int LPC_order, /* I LPC order */ const SKP_int16 x[], /* I Input signal */ const SKP_int subfr_length /* I Input signal subframe length including preceeding samples */ ) { SKP_int k; SKP_int32 a_Q16[ MAX_LPC_ORDER ]; SKP_int isInterpLower, shift; SKP_int16 S[ MAX_LPC_ORDER ]; SKP_int32 res_nrg0, res_nrg1; SKP_int rshift0, rshift1; /* Used only for LSF interpolation */ SKP_int32 a_tmp_Q16[ MAX_LPC_ORDER ], res_nrg_interp, res_nrg, res_tmp_nrg; SKP_int res_nrg_interp_Q, res_nrg_Q, res_tmp_nrg_Q; SKP_int16 a_tmp_Q12[ MAX_LPC_ORDER ]; SKP_int NLSF0_Q15[ MAX_LPC_ORDER ]; SKP_int16 LPC_res[ ( MAX_FRAME_LENGTH + NB_SUBFR * MAX_LPC_ORDER ) / 2 ]; /* Default: no interpolation */ *interpIndex = 4; /* Burg AR analysis for the full frame */ SKP_Silk_burg_modified( &res_nrg, &res_nrg_Q, a_Q16, x, subfr_length, NB_SUBFR, SKP_FIX_CONST( FIND_LPC_COND_FAC, 32 ), LPC_order ); SKP_Silk_bwexpander_32( a_Q16, LPC_order, SKP_FIX_CONST( FIND_LPC_CHIRP, 16 ) ); if( useInterpolatedNLSFs == 1 ) { /* Optimal solution for last 10 ms */ SKP_Silk_burg_modified( &res_tmp_nrg, &res_tmp_nrg_Q, a_tmp_Q16, x + ( NB_SUBFR >> 1 ) * subfr_length, subfr_length, ( NB_SUBFR >> 1 ), SKP_FIX_CONST( FIND_LPC_COND_FAC, 32 ), LPC_order ); SKP_Silk_bwexpander_32( a_tmp_Q16, LPC_order, SKP_FIX_CONST( FIND_LPC_CHIRP, 16 ) ); /* subtract residual energy here, as that's easier than adding it to the */ /* residual energy of the first 10 ms in each iteration of the search below */ shift = res_tmp_nrg_Q - res_nrg_Q; if( shift >= 0 ) { if( shift < 32 ) { res_nrg = res_nrg - SKP_RSHIFT( res_tmp_nrg, shift ); } } else { SKP_assert( shift > -32 ); res_nrg = SKP_RSHIFT( res_nrg, -shift ) - res_tmp_nrg; res_nrg_Q = res_tmp_nrg_Q; } /* Convert to NLSFs */ SKP_Silk_A2NLSF( NLSF_Q15, a_tmp_Q16, LPC_order ); /* Search over interpolation indices to find the one with lowest residual energy */ for( k = 3; k >= 0; k-- ) { /* Interpolate NLSFs for first half */ SKP_Silk_interpolate( NLSF0_Q15, prev_NLSFq_Q15, NLSF_Q15, k, LPC_order ); /* Convert to LPC for residual energy evaluation */ SKP_Silk_NLSF2A_stable( a_tmp_Q12, NLSF0_Q15, LPC_order ); /* Calculate residual energy with NLSF interpolation */ SKP_memset( S, 0, LPC_order * sizeof( SKP_int16 ) ); SKP_Silk_LPC_analysis_filter( x, a_tmp_Q12, S, LPC_res, 2 * subfr_length, LPC_order ); SKP_Silk_sum_sqr_shift( &res_nrg0, &rshift0, LPC_res + LPC_order, subfr_length - LPC_order ); SKP_Silk_sum_sqr_shift( &res_nrg1, &rshift1, LPC_res + LPC_order + subfr_length, subfr_length - LPC_order ); /* Add subframe energies from first half frame */ shift = rshift0 - rshift1; if( shift >= 0 ) { res_nrg1 = SKP_RSHIFT( res_nrg1, shift ); res_nrg_interp_Q = -rshift0; } else { res_nrg0 = SKP_RSHIFT( res_nrg0, -shift ); res_nrg_interp_Q = -rshift1; } res_nrg_interp = SKP_ADD32( res_nrg0, res_nrg1 ); /* Compare with first half energy without NLSF interpolation, or best interpolated value so far */ shift = res_nrg_interp_Q - res_nrg_Q; if( shift >= 0 ) { if( SKP_RSHIFT( res_nrg_interp, shift ) < res_nrg ) { isInterpLower = SKP_TRUE; } else { isInterpLower = SKP_FALSE; } } else { if( -shift < 32 ) { if( res_nrg_interp < SKP_RSHIFT( res_nrg, -shift ) ) { isInterpLower = SKP_TRUE; } else { isInterpLower = SKP_FALSE; } } else { isInterpLower = SKP_FALSE; } } /* Determine whether current interpolated NLSFs are best so far */ if( isInterpLower == SKP_TRUE ) { /* Interpolation has lower residual energy */ res_nrg = res_nrg_interp; res_nrg_Q = res_nrg_interp_Q; *interpIndex = k; } } }
void SKP_Silk_prefilter_FIX( SKP_Silk_encoder_state_FIX *psEnc, /* I/O Encoder state FIX */ const SKP_Silk_encoder_control_FIX *psEncCtrl, /* I Encoder control FIX */ SKP_int16 xw[], /* O Weighted signal */ const SKP_int16 x[] /* I Speech signal */ ) { SKP_Silk_prefilter_state_FIX *P = &psEnc->sPrefilt; SKP_int j, k, lag; SKP_int32 tmp_32; const SKP_int16 *AR1_shp_Q13; const SKP_int16 *px; SKP_int16 *pxw; SKP_int HarmShapeGain_Q12, Tilt_Q14; SKP_int32 HarmShapeFIRPacked_Q12, LF_shp_Q14; SKP_int32 x_filt_Q12[ MAX_FRAME_LENGTH / NB_SUBFR ]; SKP_int16 st_res[ ( MAX_FRAME_LENGTH / NB_SUBFR ) + MAX_SHAPE_LPC_ORDER ]; #if !defined(_SYSTEM_IS_BIG_ENDIAN) SKP_int32 B_Q12; #else SKP_int16 B_Q12[ 2 ]; #endif /* Setup pointers */ px = x; pxw = xw; lag = P->lagPrev; for( k = 0; k < NB_SUBFR; k++ ) { /* Update Variables that change per sub frame */ if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) { lag = psEncCtrl->sCmn.pitchL[ k ]; } /* Noise shape parameters */ HarmShapeGain_Q12 = SKP_SMULWB( psEncCtrl->HarmShapeGain_Q14[ k ], 16384 - psEncCtrl->HarmBoost_Q14[ k ] ); SKP_assert( HarmShapeGain_Q12 >= 0 ); HarmShapeFIRPacked_Q12 = SKP_RSHIFT( HarmShapeGain_Q12, 2 ); HarmShapeFIRPacked_Q12 |= SKP_LSHIFT( ( SKP_int32 )SKP_RSHIFT( HarmShapeGain_Q12, 1 ), 16 ); Tilt_Q14 = psEncCtrl->Tilt_Q14[ k ]; LF_shp_Q14 = psEncCtrl->LF_shp_Q14[ k ]; AR1_shp_Q13 = &psEncCtrl->AR1_Q13[ k * MAX_SHAPE_LPC_ORDER ]; /* Short term FIR filtering*/ SKP_Silk_warped_LPC_analysis_filter_FIX( P->sAR_shp, st_res, AR1_shp_Q13, px, psEnc->sCmn.warping_Q16, psEnc->sCmn.subfr_length, psEnc->sCmn.shapingLPCOrder ); /* reduce (mainly) low frequencies during harmonic emphasis */ #if !defined(_SYSTEM_IS_BIG_ENDIAN) /* NOTE: the code below loads two int16 values in an int32, and multiplies each using the */ /* SMLABB and SMLABT instructions. On a big-endian CPU the two int16 variables would be */ /* loaded in reverse order and the code will give the wrong result. In that case swapping */ /* the SMLABB and SMLABT instructions should solve the problem. */ B_Q12 = SKP_RSHIFT_ROUND( psEncCtrl->GainsPre_Q14[ k ], 2 ); tmp_32 = SKP_SMLABB( SKP_FIX_CONST( INPUT_TILT, 26 ), psEncCtrl->HarmBoost_Q14[ k ], HarmShapeGain_Q12 ); /* Q26 */ tmp_32 = SKP_SMLABB( tmp_32, psEncCtrl->coding_quality_Q14, SKP_FIX_CONST( HIGH_RATE_INPUT_TILT, 12 ) ); /* Q26 */ tmp_32 = SKP_SMULWB( tmp_32, -psEncCtrl->GainsPre_Q14[ k ] ); /* Q24 */ tmp_32 = SKP_RSHIFT_ROUND( tmp_32, 12 ); /* Q12 */ B_Q12 |= SKP_LSHIFT( SKP_SAT16( tmp_32 ), 16 ); x_filt_Q12[ 0 ] = SKP_SMLABT( SKP_SMULBB( st_res[ 0 ], B_Q12 ), P->sHarmHP, B_Q12 ); for( j = 1; j < psEnc->sCmn.subfr_length; j++ ) { x_filt_Q12[ j ] = SKP_SMLABT( SKP_SMULBB( st_res[ j ], B_Q12 ), st_res[ j - 1 ], B_Q12 ); } #else B_Q12[ 0 ] = SKP_RSHIFT_ROUND( psEncCtrl->GainsPre_Q14[ k ], 2 ); tmp_32 = SKP_SMLABB( SKP_FIX_CONST( INPUT_TILT, 26 ), psEncCtrl->HarmBoost_Q14[ k ], HarmShapeGain_Q12 ); /* Q26 */ tmp_32 = SKP_SMLABB( tmp_32, psEncCtrl->coding_quality_Q14, SKP_FIX_CONST( HIGH_RATE_INPUT_TILT, 12 ) ); /* Q26 */ tmp_32 = SKP_SMULWB( tmp_32, -psEncCtrl->GainsPre_Q14[ k ] ); /* Q24 */ tmp_32 = SKP_RSHIFT_ROUND( tmp_32, 12 ); /* Q12 */ B_Q12[ 1 ]= SKP_SAT16( tmp_32 ); x_filt_Q12[ 0 ] = SKP_SMLABB( SKP_SMULBB( st_res[ 0 ], B_Q12[ 0 ] ), P->sHarmHP, B_Q12[ 1 ] ); for( j = 1; j < psEnc->sCmn.subfr_length; j++ ) { x_filt_Q12[ j ] = SKP_SMLABB( SKP_SMULBB( st_res[ j ], B_Q12[ 0 ] ), st_res[ j - 1 ], B_Q12[ 1 ] ); } #endif P->sHarmHP = st_res[ psEnc->sCmn.subfr_length - 1 ]; SKP_Silk_prefilt_FIX( P, x_filt_Q12, pxw, HarmShapeFIRPacked_Q12, Tilt_Q14, LF_shp_Q14, lag, psEnc->sCmn.subfr_length ); px += psEnc->sCmn.subfr_length; pxw += psEnc->sCmn.subfr_length; } P->lagPrev = psEncCtrl->sCmn.pitchL[ NB_SUBFR - 1 ]; }
void SKP_Silk_NLSF_MSVQ_encode_FIX( SKP_int *NLSFIndices, /* O Codebook path vector [ CB_STAGES ] */ SKP_int *pNLSF_Q15, /* I/O Quantized NLSF vector [ LPC_ORDER ] */ const SKP_Silk_NLSF_CB_struct *psNLSF_CB, /* I Codebook object */ const SKP_int *pNLSF_q_Q15_prev, /* I Prev. quantized NLSF vector [LPC_ORDER] */ const SKP_int *pW_Q6, /* I NLSF weight vector [ LPC_ORDER ] */ const SKP_int NLSF_mu_Q15, /* I Rate weight for the RD optimization */ const SKP_int NLSF_mu_fluc_red_Q16, /* I Fluctuation reduction error weight */ const SKP_int NLSF_MSVQ_Survivors, /* I Max survivors from each stage */ const SKP_int LPC_order, /* I LPC order */ const SKP_int deactivate_fluc_red /* I Deactivate fluctuation reduction */ ) { SKP_int i, s, k, cur_survivors = 0, prev_survivors, min_survivors, input_index, cb_index, bestIndex; SKP_int32 rateDistThreshold_Q18; #if( NLSF_MSVQ_FLUCTUATION_REDUCTION == 1 ) SKP_int32 se_Q15, wsse_Q20, bestRateDist_Q20; #endif #if( LOW_COMPLEXITY_ONLY == 1 ) SKP_int32 pRateDist_Q18[ NLSF_MSVQ_TREE_SEARCH_MAX_VECTORS_EVALUATED_LC_MODE ]; SKP_int32 pRate_Q5[ MAX_NLSF_MSVQ_SURVIVORS_LC_MODE ]; SKP_int32 pRate_new_Q5[ MAX_NLSF_MSVQ_SURVIVORS_LC_MODE ]; SKP_int pTempIndices[ MAX_NLSF_MSVQ_SURVIVORS_LC_MODE ]; SKP_int pPath[ MAX_NLSF_MSVQ_SURVIVORS_LC_MODE * NLSF_MSVQ_MAX_CB_STAGES ]; SKP_int pPath_new[ MAX_NLSF_MSVQ_SURVIVORS_LC_MODE * NLSF_MSVQ_MAX_CB_STAGES ]; SKP_int pRes_Q15[ MAX_NLSF_MSVQ_SURVIVORS_LC_MODE * MAX_LPC_ORDER ]; SKP_int pRes_new_Q15[ MAX_NLSF_MSVQ_SURVIVORS_LC_MODE * MAX_LPC_ORDER ]; #else SKP_int32 pRateDist_Q18[ NLSF_MSVQ_TREE_SEARCH_MAX_VECTORS_EVALUATED ]; SKP_int32 pRate_Q5[ MAX_NLSF_MSVQ_SURVIVORS ]; SKP_int32 pRate_new_Q5[ MAX_NLSF_MSVQ_SURVIVORS ]; SKP_int pTempIndices[ MAX_NLSF_MSVQ_SURVIVORS ]; SKP_int pPath[ MAX_NLSF_MSVQ_SURVIVORS * NLSF_MSVQ_MAX_CB_STAGES ]; SKP_int pPath_new[ MAX_NLSF_MSVQ_SURVIVORS * NLSF_MSVQ_MAX_CB_STAGES ]; SKP_int pRes_Q15[ MAX_NLSF_MSVQ_SURVIVORS * MAX_LPC_ORDER ]; SKP_int pRes_new_Q15[ MAX_NLSF_MSVQ_SURVIVORS * MAX_LPC_ORDER ]; #endif const SKP_int *pConstInt; SKP_int *pInt; const SKP_int16 *pCB_element; const SKP_Silk_NLSF_CBS *pCurrentCBStage; #ifdef USE_UNQUANTIZED_LSFS SKP_int NLSF_orig[ MAX_LPC_ORDER ]; SKP_memcpy( NLSF_orig, pNLSF_Q15, LPC_order * sizeof( SKP_int ) ); #endif SKP_assert( NLSF_MSVQ_Survivors <= MAX_NLSF_MSVQ_SURVIVORS ); SKP_assert( ( LOW_COMPLEXITY_ONLY == 0 ) || ( NLSF_MSVQ_Survivors <= MAX_NLSF_MSVQ_SURVIVORS_LC_MODE ) ); /****************************************************/ /* Tree search for the multi-stage vector quantizer */ /****************************************************/ /* Clear accumulated rates */ SKP_memset( pRate_Q5, 0, NLSF_MSVQ_Survivors * sizeof( SKP_int32 ) ); /* Copy NLSFs into residual signal vector */ for( i = 0; i < LPC_order; i++ ) { pRes_Q15[ i ] = pNLSF_Q15[ i ]; } /* Set first stage values */ prev_survivors = 1; /* Minimum number of survivors */ min_survivors = NLSF_MSVQ_Survivors / 2; /* Loop over all stages */ for( s = 0; s < psNLSF_CB->nStages; s++ ) { /* Set a pointer to the current stage codebook */ pCurrentCBStage = &psNLSF_CB->CBStages[ s ]; /* Calculate the number of survivors in the current stage */ cur_survivors = SKP_min_32( NLSF_MSVQ_Survivors, SKP_SMULBB( prev_survivors, pCurrentCBStage->nVectors ) ); #if( NLSF_MSVQ_FLUCTUATION_REDUCTION == 0 ) /* Find a single best survivor in the last stage, if we */ /* do not need candidates for fluctuation reduction */ if( s == psNLSF_CB->nStages - 1 ) { cur_survivors = 1; } #endif /* Nearest neighbor clustering for multiple input data vectors */ SKP_Silk_NLSF_VQ_rate_distortion_FIX( pRateDist_Q18, pCurrentCBStage, pRes_Q15, pW_Q6, pRate_Q5, NLSF_mu_Q15, prev_survivors, LPC_order ); /* Sort the rate-distortion errors */ SKP_Silk_insertion_sort_increasing( pRateDist_Q18, pTempIndices, prev_survivors * pCurrentCBStage->nVectors, cur_survivors ); /* Discard survivors with rate-distortion values too far above the best one */ if( pRateDist_Q18[ 0 ] < SKP_int32_MAX / MAX_NLSF_MSVQ_SURVIVORS ) { rateDistThreshold_Q18 = SKP_SMLAWB( pRateDist_Q18[ 0 ], SKP_MUL( NLSF_MSVQ_Survivors, pRateDist_Q18[ 0 ] ), SKP_FIX_CONST( NLSF_MSVQ_SURV_MAX_REL_RD, 16 ) ); while( pRateDist_Q18[ cur_survivors - 1 ] > rateDistThreshold_Q18 && cur_survivors > min_survivors ) { cur_survivors--; } } /* Update accumulated codebook contributions for the 'cur_survivors' best codebook indices */ for( k = 0; k < cur_survivors; k++ ) { if( s > 0 ) { /* Find the indices of the input and the codebook vector */ if( pCurrentCBStage->nVectors == 8 ) { input_index = SKP_RSHIFT( pTempIndices[ k ], 3 ); cb_index = pTempIndices[ k ] & 7; } else { input_index = SKP_DIV32_16( pTempIndices[ k ], pCurrentCBStage->nVectors ); cb_index = pTempIndices[ k ] - SKP_SMULBB( input_index, pCurrentCBStage->nVectors ); } } else { /* Find the indices of the input and the codebook vector */ input_index = 0; cb_index = pTempIndices[ k ]; } /* Subtract new contribution from the previous residual vector for each of 'cur_survivors' */ pConstInt = &pRes_Q15[ SKP_SMULBB( input_index, LPC_order ) ]; pCB_element = &pCurrentCBStage->CB_NLSF_Q15[ SKP_SMULBB( cb_index, LPC_order ) ]; pInt = &pRes_new_Q15[ SKP_SMULBB( k, LPC_order ) ]; for( i = 0; i < LPC_order; i++ ) { pInt[ i ] = pConstInt[ i ] - ( SKP_int )pCB_element[ i ]; } /* Update accumulated rate for stage 1 to the current */ pRate_new_Q5[ k ] = pRate_Q5[ input_index ] + pCurrentCBStage->Rates_Q5[ cb_index ]; /* Copy paths from previous matrix, starting with the best path */ pConstInt = &pPath[ SKP_SMULBB( input_index, psNLSF_CB->nStages ) ]; pInt = &pPath_new[ SKP_SMULBB( k, psNLSF_CB->nStages ) ]; for( i = 0; i < s; i++ ) { pInt[ i ] = pConstInt[ i ]; } /* Write the current stage indices for the 'cur_survivors' to the best path matrix */ pInt[ s ] = cb_index; } if( s < psNLSF_CB->nStages - 1 ) { /* Copy NLSF residual matrix for next stage */ SKP_memcpy( pRes_Q15, pRes_new_Q15, SKP_SMULBB( cur_survivors, LPC_order ) * sizeof( SKP_int ) ); /* Copy rate vector for next stage */ SKP_memcpy( pRate_Q5, pRate_new_Q5, cur_survivors * sizeof( SKP_int32 ) ); /* Copy best path matrix for next stage */ SKP_memcpy( pPath, pPath_new, SKP_SMULBB( cur_survivors, psNLSF_CB->nStages ) * sizeof( SKP_int ) ); } prev_survivors = cur_survivors; } /* (Preliminary) index of the best survivor, later to be decoded */ bestIndex = 0; #if( NLSF_MSVQ_FLUCTUATION_REDUCTION == 1 ) /******************************/ /* NLSF fluctuation reduction */ /******************************/ if( deactivate_fluc_red != 1 ) { /* Search among all survivors, now taking also weighted fluctuation errors into account */ bestRateDist_Q20 = SKP_int32_MAX; for( s = 0; s < cur_survivors; s++ ) { /* Decode survivor to compare with previous quantized NLSF vector */ SKP_Silk_NLSF_MSVQ_decode( pNLSF_Q15, psNLSF_CB, &pPath_new[ SKP_SMULBB( s, psNLSF_CB->nStages ) ], LPC_order ); /* Compare decoded NLSF vector with the previously quantized vector */ wsse_Q20 = 0; for( i = 0; i < LPC_order; i += 2 ) { /* Compute weighted squared quantization error for index i */ se_Q15 = pNLSF_Q15[ i ] - pNLSF_q_Q15_prev[ i ]; // range: [ -32767 : 32767 ] wsse_Q20 = SKP_SMLAWB( wsse_Q20, SKP_SMULBB( se_Q15, se_Q15 ), pW_Q6[ i ] ); /* Compute weighted squared quantization error for index i + 1 */ se_Q15 = pNLSF_Q15[ i + 1 ] - pNLSF_q_Q15_prev[ i + 1 ]; // range: [ -32767 : 32767 ] wsse_Q20 = SKP_SMLAWB( wsse_Q20, SKP_SMULBB( se_Q15, se_Q15 ), pW_Q6[ i + 1 ] ); } SKP_assert( wsse_Q20 >= 0 ); /* Add the fluctuation reduction penalty to the rate distortion error */ wsse_Q20 = SKP_ADD_POS_SAT32( pRateDist_Q18[ s ], SKP_SMULWB( wsse_Q20, NLSF_mu_fluc_red_Q16 ) ); /* Keep index of best survivor */ if( wsse_Q20 < bestRateDist_Q20 ) { bestRateDist_Q20 = wsse_Q20; bestIndex = s; } } } #endif /* Copy best path to output argument */ SKP_memcpy( NLSFIndices, &pPath_new[ SKP_SMULBB( bestIndex, psNLSF_CB->nStages ) ], psNLSF_CB->nStages * sizeof( SKP_int ) ); /* Decode and stabilize the best survivor */ SKP_Silk_NLSF_MSVQ_decode( pNLSF_Q15, psNLSF_CB, NLSFIndices, LPC_order ); #ifdef USE_UNQUANTIZED_LSFS SKP_memcpy( pNLSF_Q15, NLSF_orig, LPC_order * sizeof( SKP_int ) ); #endif }