ref: 69abbf4662453350324bf2ac989f499d0d0ddabf
dir: /silk/silk_NSQ.c/
/***********************************************************************
Copyright (c) 2006-2011, Skype Limited. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, (subject to the limitations in the disclaimer below)
are permitted provided that the following conditions are met:
- Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
- Neither the name of Skype Limited, nor the names of specific
contributors, may be used to endorse or promote products derived from
this software without specific prior written permission.
NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED
BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
***********************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "silk_main.h"
static inline void silk_nsq_scale_states(
const silk_encoder_state *psEncC, /* I Encoder State */
silk_nsq_state *NSQ, /* I/O NSQ state */
const opus_int16 x[], /* I input in Q0 */
opus_int32 x_sc_Q10[], /* O input scaled with 1/Gain */
const opus_int16 sLTP[], /* I re-whitened LTP state in Q0 */
opus_int32 sLTP_Q16[], /* O LTP state matching scaled input */
opus_int subfr, /* I subframe number */
const opus_int LTP_scale_Q14, /* I */
const opus_int32 Gains_Q16[ MAX_NB_SUBFR ], /* I */
const opus_int pitchL[ MAX_NB_SUBFR ] /* I */
);
static inline void silk_noise_shape_quantizer(
silk_nsq_state *NSQ, /* I/O NSQ state */
opus_int signalType, /* I Signal type */
const opus_int32 x_sc_Q10[], /* I */
opus_int8 pulses[], /* O */
opus_int16 xq[], /* O */
opus_int32 sLTP_Q16[], /* I/O LTP state */
const opus_int16 a_Q12[], /* I Short term prediction coefs */
const opus_int16 b_Q14[], /* I Long term prediction coefs */
const opus_int16 AR_shp_Q13[], /* I Noise shaping AR coefs */
opus_int lag, /* I Pitch lag */
opus_int32 HarmShapeFIRPacked_Q14, /* I */
opus_int Tilt_Q14, /* I Spectral tilt */
opus_int32 LF_shp_Q14, /* I */
opus_int32 Gain_Q16, /* I */
opus_int Lambda_Q10, /* I */
opus_int offset_Q10, /* I */
opus_int length, /* I Input length */
opus_int shapingLPCOrder, /* I Noise shaping AR filter order */
opus_int predictLPCOrder /* I Prediction filter order */
);
void silk_NSQ(
const silk_encoder_state *psEncC, /* I/O Encoder State */
silk_nsq_state *NSQ, /* I/O NSQ state */
SideInfoIndices *psIndices, /* I/O Quantization Indices */
const opus_int16 x[], /* I prefiltered input signal */
opus_int8 pulses[], /* O quantized qulse signal */
const opus_int16 PredCoef_Q12[ 2 * MAX_LPC_ORDER ], /* I Short term prediction coefficients */
const opus_int16 LTPCoef_Q14[ LTP_ORDER * MAX_NB_SUBFR ], /* I Long term prediction coefficients */
const opus_int16 AR2_Q13[ MAX_NB_SUBFR * MAX_SHAPE_LPC_ORDER ], /* I */
const opus_int HarmShapeGain_Q14[ MAX_NB_SUBFR ], /* I */
const opus_int Tilt_Q14[ MAX_NB_SUBFR ], /* I Spectral tilt */
const opus_int32 LF_shp_Q14[ MAX_NB_SUBFR ], /* I */
const opus_int32 Gains_Q16[ MAX_NB_SUBFR ], /* I */
const opus_int pitchL[ MAX_NB_SUBFR ], /* I */
const opus_int Lambda_Q10, /* I */
const opus_int LTP_scale_Q14 /* I LTP state scaling */
)
{
opus_int k, lag, start_idx, LSF_interpolation_flag;
const opus_int16 *A_Q12, *B_Q14, *AR_shp_Q13;
opus_int16 *pxq;
opus_int32 sLTP_Q16[ 2 * MAX_FRAME_LENGTH ];
opus_int16 sLTP[ 2 * MAX_FRAME_LENGTH ];
opus_int32 HarmShapeFIRPacked_Q14;
opus_int offset_Q10;
opus_int32 x_sc_Q10[ MAX_FRAME_LENGTH / MAX_NB_SUBFR ];
NSQ->rand_seed = psIndices->Seed;
/* Set unvoiced lag to the previous one, overwrite later for voiced */
lag = NSQ->lagPrev;
SKP_assert( NSQ->prev_inv_gain_Q16 != 0 );
offset_Q10 = silk_Quantization_Offsets_Q10[ psIndices->signalType >> 1 ][ psIndices->quantOffsetType ];
if( psIndices->NLSFInterpCoef_Q2 == 4 ) {
LSF_interpolation_flag = 0;
} else {
LSF_interpolation_flag = 1;
}
/* Setup pointers to start of sub frame */
NSQ->sLTP_shp_buf_idx = psEncC->ltp_mem_length;
NSQ->sLTP_buf_idx = psEncC->ltp_mem_length;
pxq = &NSQ->xq[ psEncC->ltp_mem_length ];
for( k = 0; k < psEncC->nb_subfr; k++ ) {
A_Q12 = &PredCoef_Q12[ (( k >> 1 ) | ( 1 - LSF_interpolation_flag )) * MAX_LPC_ORDER ];
B_Q14 = <PCoef_Q14[ k * LTP_ORDER ];
AR_shp_Q13 = &AR2_Q13[ k * MAX_SHAPE_LPC_ORDER ];
/* Noise shape parameters */
SKP_assert( HarmShapeGain_Q14[ k ] >= 0 );
HarmShapeFIRPacked_Q14 = SKP_RSHIFT( HarmShapeGain_Q14[ k ], 2 );
HarmShapeFIRPacked_Q14 |= SKP_LSHIFT( ( opus_int32 )SKP_RSHIFT( HarmShapeGain_Q14[ k ], 1 ), 16 );
NSQ->rewhite_flag = 0;
if( psIndices->signalType == TYPE_VOICED ) {
/* Voiced */
lag = pitchL[ k ];
/* Re-whitening */
if( ( k & ( 3 - SKP_LSHIFT( LSF_interpolation_flag, 1 ) ) ) == 0 ) {
/* Rewhiten with new A coefs */
start_idx = psEncC->ltp_mem_length - lag - psEncC->predictLPCOrder - LTP_ORDER / 2;
SKP_assert( start_idx > 0 );
silk_LPC_analysis_filter( &sLTP[ start_idx ], &NSQ->xq[ start_idx + k * psEncC->subfr_length ],
A_Q12, psEncC->ltp_mem_length - start_idx, psEncC->predictLPCOrder );
NSQ->rewhite_flag = 1;
NSQ->sLTP_buf_idx = psEncC->ltp_mem_length;
}
}
silk_nsq_scale_states( psEncC, NSQ, x, x_sc_Q10, sLTP, sLTP_Q16, k, LTP_scale_Q14, Gains_Q16, pitchL );
silk_noise_shape_quantizer( NSQ, psIndices->signalType, x_sc_Q10, pulses, pxq, sLTP_Q16, A_Q12, B_Q14,
AR_shp_Q13, lag, HarmShapeFIRPacked_Q14, Tilt_Q14[ k ], LF_shp_Q14[ k ], Gains_Q16[ k ], Lambda_Q10,
offset_Q10, psEncC->subfr_length, psEncC->shapingLPCOrder, psEncC->predictLPCOrder );
x += psEncC->subfr_length;
pulses += psEncC->subfr_length;
pxq += psEncC->subfr_length;
}
/* Update lagPrev for next frame */
NSQ->lagPrev = pitchL[ psEncC->nb_subfr - 1 ];
/* Save quantized speech and noise shaping signals */
SKP_memmove( NSQ->xq, &NSQ->xq[ psEncC->frame_length ], psEncC->ltp_mem_length * sizeof( opus_int16 ) );
SKP_memmove( NSQ->sLTP_shp_Q10, &NSQ->sLTP_shp_Q10[ psEncC->frame_length ], psEncC->ltp_mem_length * sizeof( opus_int32 ) );
#ifdef SAVE_ALL_INTERNAL_DATA
DEBUG_STORE_DATA( xq.dat, &pxq[ -psEncC->frame_length ], psEncC->frame_length * sizeof( opus_int16 ) );
DEBUG_STORE_DATA( q.dat, &pulses[ -psEncC->frame_length ], psEncC->frame_length * sizeof( opus_int8 ) );
DEBUG_STORE_DATA( sLTP_Q16.dat, &sLTP_Q16[ psEncC->ltp_mem_length ], psEncC->frame_length * sizeof( opus_int32 ) );
#endif
}
/***********************************/
/* silk_noise_shape_quantizer */
/***********************************/
static inline void silk_noise_shape_quantizer(
silk_nsq_state *NSQ, /* I/O NSQ state */
opus_int signalType, /* I Signal type */
const opus_int32 x_sc_Q10[], /* I */
opus_int8 pulses[], /* O */
opus_int16 xq[], /* O */
opus_int32 sLTP_Q16[], /* I/O LTP state */
const opus_int16 a_Q12[], /* I Short term prediction coefs */
const opus_int16 b_Q14[], /* I Long term prediction coefs */
const opus_int16 AR_shp_Q13[], /* I Noise shaping AR coefs */
opus_int lag, /* I Pitch lag */
opus_int32 HarmShapeFIRPacked_Q14, /* I */
opus_int Tilt_Q14, /* I Spectral tilt */
opus_int32 LF_shp_Q14, /* I */
opus_int32 Gain_Q16, /* I */
opus_int Lambda_Q10, /* I */
opus_int offset_Q10, /* I */
opus_int length, /* I Input length */
opus_int shapingLPCOrder, /* I Noise shaping AR filter order */
opus_int predictLPCOrder /* I Prediction filter order */
)
{
opus_int i, j;
opus_int32 LTP_pred_Q14, LPC_pred_Q10, n_AR_Q10, n_LTP_Q14;
opus_int32 n_LF_Q10, r_Q10, rr_Q10, q1_Q10, q2_Q10, rd1_Q10, rd2_Q10;
opus_int32 dither, exc_Q10, LPC_exc_Q10, xq_Q10;
opus_int32 tmp1, tmp2, sLF_AR_shp_Q10;
opus_int32 *psLPC_Q14, *shp_lag_ptr, *pred_lag_ptr;
shp_lag_ptr = &NSQ->sLTP_shp_Q10[ NSQ->sLTP_shp_buf_idx - lag + HARM_SHAPE_FIR_TAPS / 2 ];
pred_lag_ptr = &sLTP_Q16[ NSQ->sLTP_buf_idx - lag + LTP_ORDER / 2 ];
/* Setup short term AR state */
psLPC_Q14 = &NSQ->sLPC_Q14[ NSQ_LPC_BUF_LENGTH - 1 ];
for( i = 0; i < length; i++ ) {
/* Generate dither */
NSQ->rand_seed = SKP_RAND( NSQ->rand_seed );
/* dither = rand_seed < 0 ? 0xFFFFFFFF : 0; */
dither = SKP_RSHIFT( NSQ->rand_seed, 31 );
/* Short-term prediction */
SKP_assert( ( predictLPCOrder & 1 ) == 0 ); /* check that order is even */
SKP_assert( ( (opus_int64)a_Q12 & 3 ) == 0 ); /* check that array starts at 4-byte aligned address */
SKP_assert( predictLPCOrder >= 10 ); /* check that unrolling works */
/* Partially unrolled */
LPC_pred_Q10 = SKP_SMULWB( psLPC_Q14[ 0 ], a_Q12[ 0 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psLPC_Q14[ -1 ], a_Q12[ 1 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psLPC_Q14[ -2 ], a_Q12[ 2 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psLPC_Q14[ -3 ], a_Q12[ 3 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psLPC_Q14[ -4 ], a_Q12[ 4 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psLPC_Q14[ -5 ], a_Q12[ 5 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psLPC_Q14[ -6 ], a_Q12[ 6 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psLPC_Q14[ -7 ], a_Q12[ 7 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psLPC_Q14[ -8 ], a_Q12[ 8 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psLPC_Q14[ -9 ], a_Q12[ 9 ] );
for( j = 10; j < predictLPCOrder; j ++ ) {
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psLPC_Q14[ -j ], a_Q12[ j ] );
}
/* Long-term prediction */
if( signalType == TYPE_VOICED ) {
/* Unrolled loop */
LTP_pred_Q14 = SKP_SMULWB( pred_lag_ptr[ 0 ], b_Q14[ 0 ] );
LTP_pred_Q14 = SKP_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -1 ], b_Q14[ 1 ] );
LTP_pred_Q14 = SKP_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -2 ], b_Q14[ 2 ] );
LTP_pred_Q14 = SKP_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -3 ], b_Q14[ 3 ] );
LTP_pred_Q14 = SKP_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -4 ], b_Q14[ 4 ] );
pred_lag_ptr++;
} else {
LTP_pred_Q14 = 0;
}
/* Noise shape feedback */
SKP_assert( ( shapingLPCOrder & 1 ) == 0 ); /* check that order is even */
tmp2 = psLPC_Q14[ 0 ];
tmp1 = NSQ->sAR2_Q14[ 0 ];
NSQ->sAR2_Q14[ 0 ] = tmp2;
n_AR_Q10 = SKP_SMULWB( tmp2, AR_shp_Q13[ 0 ] );
for( j = 2; j < shapingLPCOrder; j += 2 ) {
tmp2 = NSQ->sAR2_Q14[ j - 1 ];
NSQ->sAR2_Q14[ j - 1 ] = tmp1;
n_AR_Q10 = SKP_SMLAWB( n_AR_Q10, tmp1, AR_shp_Q13[ j - 1 ] );
tmp1 = NSQ->sAR2_Q14[ j + 0 ];
NSQ->sAR2_Q14[ j + 0 ] = tmp2;
n_AR_Q10 = SKP_SMLAWB( n_AR_Q10, tmp2, AR_shp_Q13[ j ] );
}
NSQ->sAR2_Q14[ shapingLPCOrder - 1 ] = tmp1;
n_AR_Q10 = SKP_SMLAWB( n_AR_Q10, tmp1, AR_shp_Q13[ shapingLPCOrder - 1 ] );
n_AR_Q10 = SKP_RSHIFT( n_AR_Q10, 1 ); /* Q11 -> Q10 */
n_AR_Q10 = SKP_SMLAWB( n_AR_Q10, NSQ->sLF_AR_shp_Q12, Tilt_Q14 );
n_LF_Q10 = SKP_LSHIFT( SKP_SMULWB( NSQ->sLTP_shp_Q10[ NSQ->sLTP_shp_buf_idx - 1 ], LF_shp_Q14 ), 2 );
n_LF_Q10 = SKP_SMLAWT( n_LF_Q10, NSQ->sLF_AR_shp_Q12, LF_shp_Q14 );
SKP_assert( lag > 0 || signalType != TYPE_VOICED );
/* Long-term shaping */
if( lag > 0 ) {
/* Symmetric, packed FIR coefficients */
n_LTP_Q14 = SKP_SMULWB( SKP_ADD32( shp_lag_ptr[ 0 ], shp_lag_ptr[ -2 ] ), HarmShapeFIRPacked_Q14 );
n_LTP_Q14 = SKP_SMLAWT( n_LTP_Q14, shp_lag_ptr[ -1 ], HarmShapeFIRPacked_Q14 );
n_LTP_Q14 = SKP_LSHIFT( n_LTP_Q14, 6 );
shp_lag_ptr++;
tmp1 = SKP_SUB32( LTP_pred_Q14, n_LTP_Q14 ); /* Add Q14 stuff */
tmp1 = SKP_RSHIFT( tmp1, 4 ); /* convert to Q10 */
tmp1 = SKP_ADD32( tmp1, LPC_pred_Q10 ); /* add Q10 stuff */
tmp1 = SKP_SUB32( tmp1, n_AR_Q10 ); /* subtract Q10 stuff */
} else {
tmp1 = SKP_SUB32( LPC_pred_Q10, n_AR_Q10 ); /* subtract Q10 stuff */
}
/* Input minus prediction plus noise feedback */
//r = x[ i ] - LTP_pred - LPC_pred + n_AR + n_Tilt + n_LF + n_LTP;
tmp1 = SKP_SUB32( tmp1, n_LF_Q10 ); /* subtract Q10 stuff */
r_Q10 = SKP_SUB32( x_sc_Q10[ i ], tmp1 );
/* Flip sign depending on dither */
r_Q10 = r_Q10 ^ dither;
r_Q10 = SKP_LIMIT_32( r_Q10, -31 << 10, 30 << 10 );
/* Find two quantization level candidates and measure their rate-distortion */
q1_Q10 = SKP_SUB32( r_Q10, offset_Q10 );
q1_Q10 = SKP_RSHIFT( q1_Q10, 10 );
if( q1_Q10 > 0 ) {
q1_Q10 = SKP_SUB32( SKP_LSHIFT( q1_Q10, 10 ), QUANT_LEVEL_ADJUST_Q10 );
q1_Q10 = SKP_ADD32( q1_Q10, offset_Q10 );
q2_Q10 = SKP_ADD32( q1_Q10, 1024 );
rd1_Q10 = SKP_SMULBB( q1_Q10, Lambda_Q10 );
rd2_Q10 = SKP_SMULBB( q2_Q10, Lambda_Q10 );
} else if( q1_Q10 == 0 ) {
q1_Q10 = offset_Q10;
q2_Q10 = SKP_ADD32( q1_Q10, 1024 - QUANT_LEVEL_ADJUST_Q10 );
rd1_Q10 = SKP_SMULBB( q1_Q10, Lambda_Q10 );
rd2_Q10 = SKP_SMULBB( q2_Q10, Lambda_Q10 );
} else if( q1_Q10 == -1 ) {
q2_Q10 = offset_Q10;
q1_Q10 = SKP_SUB32( q2_Q10, 1024 - QUANT_LEVEL_ADJUST_Q10 );
rd1_Q10 = SKP_SMULBB( -q1_Q10, Lambda_Q10 );
rd2_Q10 = SKP_SMULBB( q2_Q10, Lambda_Q10 );
} else { /* Q1_Q10 < -1 */
q1_Q10 = SKP_ADD32( SKP_LSHIFT( q1_Q10, 10 ), QUANT_LEVEL_ADJUST_Q10 );
q1_Q10 = SKP_ADD32( q1_Q10, offset_Q10 );
q2_Q10 = SKP_ADD32( q1_Q10, 1024 );
rd1_Q10 = SKP_SMULBB( -q1_Q10, Lambda_Q10 );
rd2_Q10 = SKP_SMULBB( -q2_Q10, Lambda_Q10 );
}
rr_Q10 = SKP_SUB32( r_Q10, q1_Q10 );
rd1_Q10 = SKP_RSHIFT( SKP_SMLABB( rd1_Q10, rr_Q10, rr_Q10 ), 10 );
rr_Q10 = SKP_SUB32( r_Q10, q2_Q10 );
rd2_Q10 = SKP_RSHIFT( SKP_SMLABB( rd2_Q10, rr_Q10, rr_Q10 ), 10 );
if( rd2_Q10 < rd1_Q10 ) {
q1_Q10 = q2_Q10;
}
pulses[ i ] = ( opus_int8 )SKP_RSHIFT_ROUND( q1_Q10, 10 );
/* Excitation */
exc_Q10 = q1_Q10 ^ dither;
/* Add predictions */
LPC_exc_Q10 = SKP_ADD32( exc_Q10, SKP_RSHIFT_ROUND( LTP_pred_Q14, 4 ) );
xq_Q10 = SKP_ADD32( LPC_exc_Q10, LPC_pred_Q10 );
/* Scale XQ back to normal level before saving */
xq[ i ] = ( opus_int16 )SKP_SAT16( SKP_RSHIFT_ROUND( SKP_SMULWW( xq_Q10, Gain_Q16 ), 10 ) );
/* Update states */
psLPC_Q14++;
*psLPC_Q14 = SKP_LSHIFT( xq_Q10, 4 );
sLF_AR_shp_Q10 = SKP_SUB32( xq_Q10, n_AR_Q10 );
NSQ->sLF_AR_shp_Q12 = SKP_LSHIFT( sLF_AR_shp_Q10, 2 );
NSQ->sLTP_shp_Q10[ NSQ->sLTP_shp_buf_idx ] = SKP_SUB32( sLF_AR_shp_Q10, n_LF_Q10 );
sLTP_Q16[ NSQ->sLTP_buf_idx ] = SKP_LSHIFT( LPC_exc_Q10, 6 );
NSQ->sLTP_shp_buf_idx++;
NSQ->sLTP_buf_idx++;
/* Make dither dependent on quantized signal */
NSQ->rand_seed += pulses[ i ];
}
/* Update LPC synth buffer */
SKP_memcpy( NSQ->sLPC_Q14, &NSQ->sLPC_Q14[ length ], NSQ_LPC_BUF_LENGTH * sizeof( opus_int32 ) );
}
static inline void silk_nsq_scale_states(
const silk_encoder_state *psEncC, /* I Encoder State */
silk_nsq_state *NSQ, /* I/O NSQ state */
const opus_int16 x[], /* I input in Q0 */
opus_int32 x_sc_Q10[], /* O input scaled with 1/Gain */
const opus_int16 sLTP[], /* I re-whitened LTP state in Q0 */
opus_int32 sLTP_Q16[], /* O LTP state matching scaled input */
opus_int subfr, /* I subframe number */
const opus_int LTP_scale_Q14, /* I */
const opus_int32 Gains_Q16[ MAX_NB_SUBFR ], /* I */
const opus_int pitchL[ MAX_NB_SUBFR ] /* I */
)
{
opus_int i, lag;
opus_int32 inv_gain_Q16, gain_adj_Q16, inv_gain_Q32;
inv_gain_Q16 = silk_INVERSE32_varQ( SKP_max( Gains_Q16[ subfr ], 1 ), 32 );
inv_gain_Q16 = SKP_min( inv_gain_Q16, SKP_int16_MAX );
lag = pitchL[ subfr ];
/* After rewhitening the LTP state is un-scaled, so scale with inv_gain_Q16 */
if( NSQ->rewhite_flag ) {
inv_gain_Q32 = SKP_LSHIFT( inv_gain_Q16, 16 );
if( subfr == 0 ) {
/* Do LTP downscaling */
inv_gain_Q32 = SKP_LSHIFT( SKP_SMULWB( inv_gain_Q32, LTP_scale_Q14 ), 2 );
}
for( i = NSQ->sLTP_buf_idx - lag - LTP_ORDER / 2; i < NSQ->sLTP_buf_idx; i++ ) {
SKP_assert( i < MAX_FRAME_LENGTH );
sLTP_Q16[ i ] = SKP_SMULWB( inv_gain_Q32, sLTP[ i ] );
}
}
/* Adjust for changing gain */
if( inv_gain_Q16 != NSQ->prev_inv_gain_Q16 ) {
gain_adj_Q16 = silk_DIV32_varQ( inv_gain_Q16, NSQ->prev_inv_gain_Q16, 16 );
/* Scale long-term shaping state */
for( i = NSQ->sLTP_shp_buf_idx - psEncC->ltp_mem_length; i < NSQ->sLTP_shp_buf_idx; i++ ) {
NSQ->sLTP_shp_Q10[ i ] = SKP_SMULWW( gain_adj_Q16, NSQ->sLTP_shp_Q10[ i ] );
}
/* Scale long-term prediction state */
if( NSQ->rewhite_flag == 0 ) {
for( i = NSQ->sLTP_buf_idx - lag - LTP_ORDER / 2; i < NSQ->sLTP_buf_idx; i++ ) {
sLTP_Q16[ i ] = SKP_SMULWW( gain_adj_Q16, sLTP_Q16[ i ] );
}
}
NSQ->sLF_AR_shp_Q12 = SKP_SMULWW( gain_adj_Q16, NSQ->sLF_AR_shp_Q12 );
/* Scale short-term prediction and shaping states */
for( i = 0; i < NSQ_LPC_BUF_LENGTH; i++ ) {
NSQ->sLPC_Q14[ i ] = SKP_SMULWW( gain_adj_Q16, NSQ->sLPC_Q14[ i ] );
}
for( i = 0; i < MAX_SHAPE_LPC_ORDER; i++ ) {
NSQ->sAR2_Q14[ i ] = SKP_SMULWW( gain_adj_Q16, NSQ->sAR2_Q14[ i ] );
}
}
/* Scale input */
for( i = 0; i < psEncC->subfr_length; i++ ) {
x_sc_Q10[ i ] = SKP_RSHIFT( SKP_SMULBB( x[ i ], ( opus_int16 )inv_gain_Q16 ), 6 );
}
/* save inv_gain */
SKP_assert( inv_gain_Q16 != 0 );
NSQ->prev_inv_gain_Q16 = inv_gain_Q16;
}