/***********************************************************************

Copyright (c) 2006-2011, Skype Limited. All rights reserved.

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modification, are permitted provided that the following conditions

are met:

- Redistributions of source code must retain the above copyright notice,

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- Redistributions in binary form must reproduce the above copyright

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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

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***********************************************************************/

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "main_FIX.h"

#include "tuning_parameters.h"

/* Compute gain to make warped filter coefficients have a zero mean log frequency response on a */

/* non-warped frequency scale. (So that it can be implemented with a minimum-phase monic filter.) */

/* Note: A monic filter is one with the first coefficient equal to 1.0. In Silk we omit the first */

/* coefficient in an array of coefficients, for monic filters. */

const opus_int32 *coefs_Q24,

opus_int lambda_Q16,

opus_int order

) {

opus_int i;

opus_int32 gain_Q24;

lambda_Q16 = -lambda_Q16;

gain_Q24 = coefs_Q24[ order - 1 ];

for( i = order - 2; i >= 0; i-- ) {

gain_Q24 = silk_SMLAWB( coefs_Q24[ i ], gain_Q24, lambda_Q16 );

}

gain_Q24 = silk_SMLAWB( SILK_FIX_CONST( 1.0, 24 ), gain_Q24, -lambda_Q16 );

return silk_INVERSE32_varQ( gain_Q24, 40 );

}

/* Convert warped filter coefficients to monic pseudo-warped coefficients and limit maximum */

/* amplitude of monic warped coefficients by using bandwidth expansion on the true coefficients */

static OPUS_INLINE void limit_warped_coefs(

opus_int32 *coefs_Q24,

opus_int lambda_Q16,

opus_int32 limit_Q24,

opus_int order

) {

opus_int i, iter, ind = 0;

/* Convert to monic coefficients */

lambda_Q16 = -lambda_Q16;

for( i = order - 1; i > 0; i-- ) {

}

lambda_Q16 = -lambda_Q16;

nom_Q16 = silk_SMLAWB( SILK_FIX_CONST( 1.0, 16 ), -(opus_int32)lambda_Q16, lambda_Q16 );

den_Q24 = silk_SMLAWB( SILK_FIX_CONST( 1.0, 24 ), coefs_Q24[ 0 ], lambda_Q16 );

gain_Q16 = silk_DIV32_varQ( nom_Q16, den_Q24, 24 );

for( iter = 0; iter < 10; iter++ ) {

/* Find maximum absolute value */

maxabs_Q24 = -1;

for( i = 0; i < order; i++ ) {

if( tmp > maxabs_Q24 ) {

maxabs_Q24 = tmp;

ind = i;

}

}

/* Use Q20 to avoid any overflow when multiplying by (ind + 1) later. */

maxabs_Q20 = silk_RSHIFT(maxabs_Q24, 4);

if( maxabs_Q20 <= limit_Q20 ) {

/* Coefficients are within range - done */

return;

}

/* Convert back to true warped coefficients */

for( i = 1; i < order; i++ ) {

}

/* Apply bandwidth expansion */

chirp_Q16 = SILK_FIX_CONST( 0.99, 16 ) - silk_DIV32_varQ(

silk_SMULWB( maxabs_Q20 - limit_Q20, silk_SMLABB( SILK_FIX_CONST( 0.8, 10 ), SILK_FIX_CONST( 0.1, 10 ), iter ) ),

silk_MUL( maxabs_Q20, ind + 1 ), 22 );

silk_bwexpander_32( coefs_Q24, order, chirp_Q16 );

/* Convert to monic warped coefficients */

lambda_Q16 = -lambda_Q16;

for( i = order - 1; i > 0; i-- ) {

}

lambda_Q16 = -lambda_Q16;

nom_Q16 = silk_SMLAWB( SILK_FIX_CONST( 1.0, 16 ), -(opus_int32)lambda_Q16, lambda_Q16 );

den_Q24 = silk_SMLAWB( SILK_FIX_CONST( 1.0, 24 ), coefs_Q24[ 0 ], lambda_Q16 );

gain_Q16 = silk_DIV32_varQ( nom_Q16, den_Q24, 24 );

}

}

silk_assert( 0 );

}

/* Disable MIPS version until it's updated. */

#if 0 && defined(MIPSr1_ASM)

#include "mips/noise_shape_analysis_FIX_mipsr1.h"

#endif

/**************************************************************/

/* Compute noise shaping coefficients and initial gain values */

/**************************************************************/

void silk_noise_shape_analysis_FIX(

silk_encoder_state_FIX *psEnc, /* I/O Encoder state FIX */

silk_encoder_control_FIX *psEncCtrl, /* I/O Encoder control FIX */

const opus_int16 *pitch_res, /* I LPC residual from pitch analysis */

const opus_int16 *x, /* I Input signal [ frame_length + la_shape ] */

int arch /* I Run-time architecture */

)

{

silk_shape_state_FIX *psShapeSt = &psEnc->sShape;

opus_int k, i, nSamples, nSegs, Qnrg, b_Q14, warping_Q16, scale = 0;

opus_int32 SNR_adj_dB_Q7, HarmShapeGain_Q16, Tilt_Q16, tmp32;

opus_int32 nrg, log_energy_Q7, log_energy_prev_Q7, energy_variation_Q7;

opus_int32 BWExp_Q16, gain_mult_Q16, gain_add_Q16, strength_Q16, b_Q8;

opus_int32 auto_corr[ MAX_SHAPE_LPC_ORDER + 1 ];

opus_int32 refl_coef_Q16[ MAX_SHAPE_LPC_ORDER ];

opus_int32 AR_Q24[ MAX_SHAPE_LPC_ORDER ];

VARDECL( opus_int16, x_windowed );

/* Point to start of first LPC analysis block */

x_ptr = x - psEnc->sCmn.la_shape;

/****************/

/* GAIN CONTROL */

/****************/

SNR_adj_dB_Q7 = psEnc->sCmn.SNR_dB_Q7;

/* Input quality is the average of the quality in the lowest two VAD bands */

psEncCtrl->input_quality_Q14 = ( opus_int )silk_RSHIFT( (opus_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 = silk_RSHIFT( silk_sigm_Q15( silk_RSHIFT_ROUND( SNR_adj_dB_Q7 -

SILK_FIX_CONST( 20.0, 7 ), 4 ) ), 1 );

/* Reduce coding SNR during low speech activity */

if( psEnc->sCmn.useCBR == 0 ) {

b_Q8 = SILK_FIX_CONST( 1.0, 8 ) - psEnc->sCmn.speech_activity_Q8;

b_Q8 = silk_SMULWB( silk_LSHIFT( b_Q8, 8 ), b_Q8 );

SNR_adj_dB_Q7 = silk_SMLAWB( SNR_adj_dB_Q7,

silk_SMULBB( SILK_FIX_CONST( -BG_SNR_DECR_dB, 7 ) >> ( 4 + 1 ), b_Q8 ), /* Q11*/

silk_SMULWB( SILK_FIX_CONST( 1.0, 14 ) + psEncCtrl->input_quality_Q14, psEncCtrl->coding_quality_Q14 ) ); /* Q12*/

}

if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {

/* Reduce gains for periodic signals */

SNR_adj_dB_Q7 = silk_SMLAWB( SNR_adj_dB_Q7, SILK_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 = silk_SMLAWB( SNR_adj_dB_Q7,

silk_SMLAWB( SILK_FIX_CONST( 6.0, 9 ), -SILK_FIX_CONST( 0.4, 18 ), psEnc->sCmn.SNR_dB_Q7 ),

SILK_FIX_CONST( 1.0, 14 ) - psEncCtrl->input_quality_Q14 );

}

/*************************/

/* SPARSENESS PROCESSING */

/*************************/

/* Set quantizer offset */

if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {

/* Initially set to 0; may be overruled in process_gains(..) */

psEnc->sCmn.indices.quantOffsetType = 0;

} else {

/* Sparseness measure, based on relative fluctuations of energy per 2 milliseconds */

nSamples = silk_LSHIFT( psEnc->sCmn.fs_kHz, 1 );

energy_variation_Q7 = 0;

log_energy_prev_Q7 = 0;

pitch_res_ptr = pitch_res;

nSegs = silk_SMULBB( SUB_FRAME_LENGTH_MS, psEnc->sCmn.nb_subfr ) / 2;

for( k = 0; k < nSegs; k++ ) {

silk_sum_sqr_shift( &nrg, &scale, pitch_res_ptr, nSamples );

nrg += silk_RSHIFT( nSamples, scale ); /* Q(-scale)*/

log_energy_Q7 = silk_lin2log( nrg );

if( k > 0 ) {

energy_variation_Q7 += silk_abs( log_energy_Q7 - log_energy_prev_Q7 );

}

log_energy_prev_Q7 = log_energy_Q7;

pitch_res_ptr += nSamples;

}

/* Set quantization offset depending on sparseness measure */

psEnc->sCmn.indices.quantOffsetType = 0;

} else {

psEnc->sCmn.indices.quantOffsetType = 1;

}

}

/*******************************/

/* Control bandwidth expansion */

/*******************************/

/* More BWE for signals with high prediction gain */

strength_Q16 = silk_SMULWB( psEncCtrl->predGain_Q16, SILK_FIX_CONST( FIND_PITCH_WHITE_NOISE_FRACTION, 16 ) );

silk_SMLAWW( SILK_FIX_CONST( 1.0, 16 ), strength_Q16, strength_Q16 ), 16 );

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 = silk_SMLAWB( psEnc->sCmn.warping_Q16, (opus_int32)psEncCtrl->coding_quality_Q14, SILK_FIX_CONST( 0.01, 18 ) );

} else {

warping_Q16 = 0;

}

/********************************************/

/* Compute noise shaping AR coefs and gains */

/********************************************/

for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {

/* Apply window: sine slope followed by flat part followed by cosine slope */

opus_int shift, slope_part, flat_part;

flat_part = psEnc->sCmn.fs_kHz * 3;

slope_part = silk_RSHIFT( psEnc->sCmn.shapeWinLength - flat_part, 1 );

silk_apply_sine_window( x_windowed, x_ptr, 1, slope_part );

shift = slope_part;

silk_memcpy( x_windowed + shift, x_ptr + shift, flat_part * sizeof(opus_int16) );

shift += flat_part;

silk_apply_sine_window( 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 */

} else {

/* Calculate regular auto correlation */

}

/* Add white noise, as a fraction of energy */

auto_corr[0] = silk_ADD32( auto_corr[0], silk_max_32( silk_SMULWB( silk_RSHIFT( auto_corr[ 0 ], 4 ),

SILK_FIX_CONST( SHAPE_WHITE_NOISE_FRACTION, 20 ) ), 1 ) );

/* Calculate the reflection coefficients using schur */

nrg = silk_schur64( refl_coef_Q16, auto_corr, psEnc->sCmn.shapingLPCOrder );

silk_assert( nrg >= 0 );

/* Convert reflection coefficients to prediction coefficients */

Qnrg = -scale; /* range: -12...30*/

silk_assert( Qnrg >= -12 );

silk_assert( Qnrg <= 30 );

/* Make sure that Qnrg is an even number */

if( Qnrg & 1 ) {

Qnrg -= 1;

nrg >>= 1;

}

tmp32 = silk_SQRT_APPROX( nrg );

Qnrg >>= 1; /* range: -6...15*/

psEncCtrl->Gains_Q16[ k ] = silk_LSHIFT_SAT32( tmp32, 16 - Qnrg );

if( psEnc->sCmn.warping_Q16 > 0 ) {

/* Adjust gain for warping */

gain_mult_Q16 = warped_gain( AR_Q24, warping_Q16, psEnc->sCmn.shapingLPCOrder );

silk_assert( psEncCtrl->Gains_Q16[ k ] > 0 );

if( psEncCtrl->Gains_Q16[ k ] < SILK_FIX_CONST( 0.25, 16 ) ) {

psEncCtrl->Gains_Q16[ k ] = silk_SMULWW( psEncCtrl->Gains_Q16[ k ], gain_mult_Q16 );

psEncCtrl->Gains_Q16[ k ] = silk_SMULWW( silk_RSHIFT_ROUND( psEncCtrl->Gains_Q16[ k ], 1 ), gain_mult_Q16 );

if ( psEncCtrl->Gains_Q16[ k ] >= ( silk_int32_MAX >> 1 ) ) {

psEncCtrl->Gains_Q16[ k ] = silk_int32_MAX;

} else {

psEncCtrl->Gains_Q16[ k ] = silk_LSHIFT32( psEncCtrl->Gains_Q16[ k ], 1 );

}

}

/* Bandwidth expansion */

silk_bwexpander_32( AR_Q24, psEnc->sCmn.shapingLPCOrder, BWExp_Q16 );

if( psEnc->sCmn.warping_Q16 > 0 ) {

/* Convert to monic warped prediction coefficients and limit absolute values */

limit_warped_coefs( AR_Q24, warping_Q16, SILK_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->AR_Q13[ k * MAX_SHAPE_LPC_ORDER + i ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( AR_Q24[ i ], 11 ) );

}

} else {

silk_LPC_fit( &psEncCtrl->AR_Q13[ k * MAX_SHAPE_LPC_ORDER ], AR_Q24, 13, 24, psEnc->sCmn.shapingLPCOrder );

}

}

/*****************/

/* Gain tweaking */

/*****************/

/* Increase gains during low speech activity and put lower limit on gains */

gain_mult_Q16 = silk_log2lin( -silk_SMLAWB( -SILK_FIX_CONST( 16.0, 7 ), SNR_adj_dB_Q7, SILK_FIX_CONST( 0.16, 16 ) ) );

gain_add_Q16 = silk_log2lin( silk_SMLAWB( SILK_FIX_CONST( 16.0, 7 ), SILK_FIX_CONST( MIN_QGAIN_DB, 7 ), SILK_FIX_CONST( 0.16, 16 ) ) );

silk_assert( gain_mult_Q16 > 0 );

for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {

psEncCtrl->Gains_Q16[ k ] = silk_SMULWW( psEncCtrl->Gains_Q16[ k ], gain_mult_Q16 );

silk_assert( psEncCtrl->Gains_Q16[ k ] >= 0 );

psEncCtrl->Gains_Q16[ k ] = silk_ADD_POS_SAT32( psEncCtrl->Gains_Q16[ k ], gain_add_Q16 );

}

/************************************************/

/* Control low-frequency shaping and noise tilt */

/************************************************/

/* Less low frequency shaping for noisy inputs */

strength_Q16 = silk_MUL( SILK_FIX_CONST( LOW_FREQ_SHAPING, 4 ), silk_SMLAWB( SILK_FIX_CONST( 1.0, 12 ),

SILK_FIX_CONST( LOW_QUALITY_LOW_FREQ_SHAPING_DECR, 13 ), psEnc->sCmn.input_quality_bands_Q15[ 0 ] - SILK_FIX_CONST( 1.0, 15 ) ) );

strength_Q16 = silk_RSHIFT( silk_MUL( strength_Q16, psEnc->sCmn.speech_activity_Q8 ), 8 );

if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {

/* Reduce low frequencies quantization noise for periodic signals, depending on pitch lag */

/*f = 400; freqz([1, -0.98 + 2e-4 * f], [1, -0.97 + 7e-4 * f], 2^12, Fs); axis([0, 1000, -10, 1])*/

opus_int fs_kHz_inv = silk_DIV32_16( SILK_FIX_CONST( 0.2, 14 ), psEnc->sCmn.fs_kHz );

for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {

b_Q14 = fs_kHz_inv + silk_DIV32_16( SILK_FIX_CONST( 3.0, 14 ), psEncCtrl->pitchL[ k ] );

/* Pack two coefficients in one int32 */

psEncCtrl->LF_shp_Q14[ k ] = silk_LSHIFT( SILK_FIX_CONST( 1.0, 14 ) - b_Q14 - silk_SMULWB( strength_Q16, b_Q14 ), 16 );

psEncCtrl->LF_shp_Q14[ k ] |= (opus_uint16)( b_Q14 - SILK_FIX_CONST( 1.0, 14 ) );

}

silk_assert( SILK_FIX_CONST( HARM_HP_NOISE_COEF, 24 ) < SILK_FIX_CONST( 0.5, 24 ) ); /* Guarantees that second argument to SMULWB() is within range of an opus_int16*/

Tilt_Q16 = - SILK_FIX_CONST( HP_NOISE_COEF, 16 ) -

silk_SMULWB( SILK_FIX_CONST( 1.0, 16 ) - SILK_FIX_CONST( HP_NOISE_COEF, 16 ),

silk_SMULWB( SILK_FIX_CONST( HARM_HP_NOISE_COEF, 24 ), psEnc->sCmn.speech_activity_Q8 ) );

} else {

b_Q14 = silk_DIV32_16( 21299, psEnc->sCmn.fs_kHz ); /* 1.3_Q0 = 21299_Q14*/

/* Pack two coefficients in one int32 */

psEncCtrl->LF_shp_Q14[ 0 ] = silk_LSHIFT( SILK_FIX_CONST( 1.0, 14 ) - b_Q14 -

silk_SMULWB( strength_Q16, silk_SMULWB( SILK_FIX_CONST( 0.6, 16 ), b_Q14 ) ), 16 );

psEncCtrl->LF_shp_Q14[ 0 ] |= (opus_uint16)( b_Q14 - SILK_FIX_CONST( 1.0, 14 ) );

for( k = 1; k < psEnc->sCmn.nb_subfr; k++ ) {

psEncCtrl->LF_shp_Q14[ k ] = psEncCtrl->LF_shp_Q14[ 0 ];

}

Tilt_Q16 = -SILK_FIX_CONST( HP_NOISE_COEF, 16 );

}

/****************************/

/* HARMONIC SHAPING CONTROL */

/****************************/

if( USE_HARM_SHAPING && psEnc->sCmn.indices.signalType == TYPE_VOICED ) {

/* More harmonic noise shaping for high bitrates or noisy input */

HarmShapeGain_Q16 = silk_SMLAWB( SILK_FIX_CONST( HARMONIC_SHAPING, 16 ),

SILK_FIX_CONST( 1.0, 16 ) - silk_SMULWB( SILK_FIX_CONST( 1.0, 18 ) - silk_LSHIFT( psEncCtrl->coding_quality_Q14, 4 ),

psEncCtrl->input_quality_Q14 ), SILK_FIX_CONST( HIGH_RATE_OR_LOW_QUALITY_HARMONIC_SHAPING, 16 ) );

/* Less harmonic noise shaping for less periodic signals */

HarmShapeGain_Q16 = silk_SMULWB( silk_LSHIFT( HarmShapeGain_Q16, 1 ),

silk_SQRT_APPROX( silk_LSHIFT( psEnc->LTPCorr_Q15, 15 ) ) );

} else {

HarmShapeGain_Q16 = 0;

}

/*************************/

/* Smooth over subframes */

/*************************/

for( k = 0; k < MAX_NB_SUBFR; k++ ) {

psShapeSt->HarmShapeGain_smth_Q16 =

silk_SMLAWB( psShapeSt->HarmShapeGain_smth_Q16, HarmShapeGain_Q16 - psShapeSt->HarmShapeGain_smth_Q16, SILK_FIX_CONST( SUBFR_SMTH_COEF, 16 ) );

psShapeSt->Tilt_smth_Q16 =

silk_SMLAWB( psShapeSt->Tilt_smth_Q16, Tilt_Q16 - psShapeSt->Tilt_smth_Q16, SILK_FIX_CONST( SUBFR_SMTH_COEF, 16 ) );

psEncCtrl->HarmShapeGain_Q14[ k ] = ( opus_int )silk_RSHIFT_ROUND( psShapeSt->HarmShapeGain_smth_Q16, 2 );

psEncCtrl->Tilt_Q14[ k ] = ( opus_int )silk_RSHIFT_ROUND( psShapeSt->Tilt_smth_Q16, 2 );

}