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authorJean-Marc Valin <jmvalin@jmvalin.ca>2011-09-16 01:16:53 -0700
committerJean-Marc Valin <jmvalin@jmvalin.ca>2011-09-16 01:16:53 -0700
commit1c2f5633d101c08b5ef8095a8682d3d52cbd952d (patch)
tree66f80e67f075db5fa5233759a89f475d8bedade2 /silk/PLC.c
parentfb3a437c9dabb4aafe4a3927158161590ed745ab (diff)
downloadopus-1c2f5633d101c08b5ef8095a8682d3d52cbd952d.tar.gz
Removed all the silk_ prefixes in source file names (not symbols)
Diffstat (limited to 'silk/PLC.c')
-rw-r--r--silk/PLC.c395
1 files changed, 395 insertions, 0 deletions
diff --git a/silk/PLC.c b/silk/PLC.c
new file mode 100644
index 00000000..43894c22
--- /dev/null
+++ b/silk/PLC.c
@@ -0,0 +1,395 @@
+/***********************************************************************
+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 "main.h"
+#include "PLC.h"
+
+#define NB_ATT 2
+static const opus_int16 HARM_ATT_Q15[NB_ATT] = { 32440, 31130 }; /* 0.99, 0.95 */
+static const opus_int16 PLC_RAND_ATTENUATE_V_Q15[NB_ATT] = { 31130, 26214 }; /* 0.95, 0.8 */
+static const opus_int16 PLC_RAND_ATTENUATE_UV_Q15[NB_ATT] = { 32440, 29491 }; /* 0.99, 0.9 */
+
+void silk_PLC_Reset(
+ silk_decoder_state *psDec /* I/O Decoder state */
+)
+{
+ psDec->sPLC.pitchL_Q8 = silk_RSHIFT( psDec->frame_length, 1 );
+}
+
+void silk_PLC(
+ silk_decoder_state *psDec, /* I Decoder state */
+ silk_decoder_control *psDecCtrl, /* I Decoder control */
+ opus_int16 frame[], /* O Concealed signal */
+ opus_int length, /* I length of residual */
+ opus_int lost /* I Loss flag */
+)
+{
+ /* PLC control function */
+ if( psDec->fs_kHz != psDec->sPLC.fs_kHz ) {
+ silk_PLC_Reset( psDec );
+ psDec->sPLC.fs_kHz = psDec->fs_kHz;
+ }
+
+ if( lost ) {
+ /****************************/
+ /* Generate Signal */
+ /****************************/
+ silk_PLC_conceal( psDec, psDecCtrl, frame, length );
+
+ psDec->lossCnt++;
+ } else {
+ /****************************/
+ /* Update state */
+ /****************************/
+ silk_PLC_update( psDec, psDecCtrl, frame, length );
+ }
+}
+
+/**************************************************/
+/* Update state of PLC */
+/**************************************************/
+void silk_PLC_update(
+ silk_decoder_state *psDec, /* (I/O) Decoder state */
+ silk_decoder_control *psDecCtrl, /* (I/O) Decoder control */
+ opus_int16 frame[],
+ opus_int length
+)
+{
+ opus_int32 LTP_Gain_Q14, temp_LTP_Gain_Q14;
+ opus_int i, j;
+ silk_PLC_struct *psPLC;
+
+ psPLC = &psDec->sPLC;
+
+ /* Update parameters used in case of packet loss */
+ psDec->prevSignalType = psDec->indices.signalType;
+ LTP_Gain_Q14 = 0;
+ if( psDec->indices.signalType == TYPE_VOICED ) {
+ /* Find the parameters for the last subframe which contains a pitch pulse */
+ for( j = 0; j * psDec->subfr_length < psDecCtrl->pitchL[ psDec->nb_subfr - 1 ]; j++ ) {
+ if( j == psDec->nb_subfr ){
+ break;
+ }
+ temp_LTP_Gain_Q14 = 0;
+ for( i = 0; i < LTP_ORDER; i++ ) {
+ temp_LTP_Gain_Q14 += psDecCtrl->LTPCoef_Q14[ ( psDec->nb_subfr - 1 - j ) * LTP_ORDER + i ];
+ }
+ if( temp_LTP_Gain_Q14 > LTP_Gain_Q14 ) {
+ LTP_Gain_Q14 = temp_LTP_Gain_Q14;
+ silk_memcpy( psPLC->LTPCoef_Q14,
+ &psDecCtrl->LTPCoef_Q14[ silk_SMULBB( psDec->nb_subfr - 1 - j, LTP_ORDER ) ],
+ LTP_ORDER * sizeof( opus_int16 ) );
+
+ psPLC->pitchL_Q8 = silk_LSHIFT( psDecCtrl->pitchL[ psDec->nb_subfr - 1 - j ], 8 );
+ }
+ }
+
+#if USE_SINGLE_TAP
+ silk_memset( psPLC->LTPCoef_Q14, 0, LTP_ORDER * sizeof( opus_int16 ) );
+ psPLC->LTPCoef_Q14[ LTP_ORDER / 2 ] = LTP_Gain_Q14;
+#endif
+
+ /* Limit LT coefs */
+ if( LTP_Gain_Q14 < V_PITCH_GAIN_START_MIN_Q14 ) {
+ opus_int scale_Q10;
+ opus_int32 tmp;
+
+ tmp = silk_LSHIFT( V_PITCH_GAIN_START_MIN_Q14, 10 );
+ scale_Q10 = silk_DIV32( tmp, silk_max( LTP_Gain_Q14, 1 ) );
+ for( i = 0; i < LTP_ORDER; i++ ) {
+ psPLC->LTPCoef_Q14[ i ] = silk_RSHIFT( silk_SMULBB( psPLC->LTPCoef_Q14[ i ], scale_Q10 ), 10 );
+ }
+ } else if( LTP_Gain_Q14 > V_PITCH_GAIN_START_MAX_Q14 ) {
+ opus_int scale_Q14;
+ opus_int32 tmp;
+
+ tmp = silk_LSHIFT( V_PITCH_GAIN_START_MAX_Q14, 14 );
+ scale_Q14 = silk_DIV32( tmp, silk_max( LTP_Gain_Q14, 1 ) );
+ for( i = 0; i < LTP_ORDER; i++ ) {
+ psPLC->LTPCoef_Q14[ i ] = silk_RSHIFT( silk_SMULBB( psPLC->LTPCoef_Q14[ i ], scale_Q14 ), 14 );
+ }
+ }
+ } else {
+ psPLC->pitchL_Q8 = silk_LSHIFT( silk_SMULBB( psDec->fs_kHz, 18 ), 8 );
+ silk_memset( psPLC->LTPCoef_Q14, 0, LTP_ORDER * sizeof( opus_int16 ));
+ }
+
+ /* Save LPC coeficients */
+ silk_memcpy( psPLC->prevLPC_Q12, psDecCtrl->PredCoef_Q12[ 1 ], psDec->LPC_order * sizeof( opus_int16 ) );
+ psPLC->prevLTP_scale_Q14 = psDecCtrl->LTP_scale_Q14;
+
+ /* Save Gains */
+ silk_memcpy( psPLC->prevGain_Q16, psDecCtrl->Gains_Q16, psDec->nb_subfr * sizeof( opus_int32 ) );
+}
+
+void silk_PLC_conceal(
+ silk_decoder_state *psDec, /* I/O Decoder state */
+ silk_decoder_control *psDecCtrl, /* I/O Decoder control */
+ opus_int16 frame[], /* O concealed signal */
+ opus_int length /* I length of residual */
+)
+{
+ opus_int i, j, k;
+ opus_int16 *B_Q14, exc_buf[ MAX_FRAME_LENGTH ], *exc_buf_ptr;
+ opus_int16 rand_scale_Q14, A_Q12_tmp[ MAX_LPC_ORDER ];
+ opus_int32 rand_seed, harm_Gain_Q15, rand_Gain_Q15;
+ opus_int lag, idx, sLTP_buf_idx, shift1, shift2;
+ opus_int32 energy1, energy2, *rand_ptr, *pred_lag_ptr;
+ opus_int32 sig_Q10[ MAX_FRAME_LENGTH ], *sig_Q10_ptr, LPC_exc_Q10, LPC_pred_Q10, LTP_pred_Q14;
+ silk_PLC_struct *psPLC;
+ psPLC = &psDec->sPLC;
+
+ /* Update LTP buffer */
+ silk_memmove( psDec->sLTP_Q16, &psDec->sLTP_Q16[ psDec->frame_length ], psDec->ltp_mem_length * sizeof( opus_int32 ) );
+
+ /* LPC concealment. Apply BWE to previous LPC */
+ silk_bwexpander( psPLC->prevLPC_Q12, psDec->LPC_order, SILK_FIX_CONST( BWE_COEF, 16 ) );
+
+ /* Find random noise component */
+ /* Scale previous excitation signal */
+ exc_buf_ptr = exc_buf;
+ /* FIXME: JMV: Is this the right fix? */
+ for (i=0;i<MAX_FRAME_LENGTH;i++)
+ exc_buf[i] = 0;
+ for( k = ( psDec->nb_subfr >> 1 ); k < psDec->nb_subfr; k++ ) {
+ for( i = 0; i < psDec->subfr_length; i++ ) {
+ exc_buf_ptr[ i ] = ( opus_int16 )silk_RSHIFT(
+ silk_SMULWW( psDec->exc_Q10[ i + k * psDec->subfr_length ], psPLC->prevGain_Q16[ k ] ), 10 );
+ }
+ exc_buf_ptr += psDec->subfr_length;
+ }
+ /* Find the subframe with lowest energy of the last two and use that as random noise generator */
+ silk_sum_sqr_shift( &energy1, &shift1, exc_buf, psDec->subfr_length );
+ silk_sum_sqr_shift( &energy2, &shift2, &exc_buf[ psDec->subfr_length ], psDec->subfr_length );
+
+ if( silk_RSHIFT( energy1, shift2 ) < silk_RSHIFT( energy2, shift1 ) ) {
+ /* First sub-frame has lowest energy */
+ rand_ptr = &psDec->exc_Q10[ silk_max_int( 0, 3 * psDec->subfr_length - RAND_BUF_SIZE ) ];
+ } else {
+ /* Second sub-frame has lowest energy */
+ rand_ptr = &psDec->exc_Q10[ silk_max_int( 0, psDec->frame_length - RAND_BUF_SIZE ) ];
+ }
+
+ /* Setup Gain to random noise component */
+ B_Q14 = psPLC->LTPCoef_Q14;
+ rand_scale_Q14 = psPLC->randScale_Q14;
+
+ /* Setup attenuation gains */
+ harm_Gain_Q15 = HARM_ATT_Q15[ silk_min_int( NB_ATT - 1, psDec->lossCnt ) ];
+ if( psDec->prevSignalType == TYPE_VOICED ) {
+ rand_Gain_Q15 = PLC_RAND_ATTENUATE_V_Q15[ silk_min_int( NB_ATT - 1, psDec->lossCnt ) ];
+ } else {
+ rand_Gain_Q15 = PLC_RAND_ATTENUATE_UV_Q15[ silk_min_int( NB_ATT - 1, psDec->lossCnt ) ];
+ }
+
+ /* First Lost frame */
+ if( psDec->lossCnt == 0 ) {
+ rand_scale_Q14 = 1 << 14;
+
+ /* Reduce random noise Gain for voiced frames */
+ if( psDec->prevSignalType == TYPE_VOICED ) {
+ for( i = 0; i < LTP_ORDER; i++ ) {
+ rand_scale_Q14 -= B_Q14[ i ];
+ }
+ rand_scale_Q14 = silk_max_16( 3277, rand_scale_Q14 ); /* 0.2 */
+ rand_scale_Q14 = ( opus_int16 )silk_RSHIFT( silk_SMULBB( rand_scale_Q14, psPLC->prevLTP_scale_Q14 ), 14 );
+ } else {
+ /* Reduce random noise for unvoiced frames with high LPC gain */
+ opus_int32 invGain_Q30, down_scale_Q30;
+
+ silk_LPC_inverse_pred_gain( &invGain_Q30, psPLC->prevLPC_Q12, psDec->LPC_order );
+
+ down_scale_Q30 = silk_min_32( silk_RSHIFT( 1 << 30, LOG2_INV_LPC_GAIN_HIGH_THRES ), invGain_Q30 );
+ down_scale_Q30 = silk_max_32( silk_RSHIFT( 1 << 30, LOG2_INV_LPC_GAIN_LOW_THRES ), down_scale_Q30 );
+ down_scale_Q30 = silk_LSHIFT( down_scale_Q30, LOG2_INV_LPC_GAIN_HIGH_THRES );
+
+ rand_Gain_Q15 = silk_RSHIFT( silk_SMULWB( down_scale_Q30, rand_Gain_Q15 ), 14 );
+ }
+ }
+
+ rand_seed = psPLC->rand_seed;
+ lag = silk_RSHIFT_ROUND( psPLC->pitchL_Q8, 8 );
+ sLTP_buf_idx = psDec->ltp_mem_length;
+
+ /***************************/
+ /* LTP synthesis filtering */
+ /***************************/
+ sig_Q10_ptr = sig_Q10;
+ for( k = 0; k < psDec->nb_subfr; k++ ) {
+ /* Setup pointer */
+ pred_lag_ptr = &psDec->sLTP_Q16[ sLTP_buf_idx - lag + LTP_ORDER / 2 ];
+ for( i = 0; i < psDec->subfr_length; i++ ) {
+ rand_seed = silk_RAND( rand_seed );
+ idx = silk_RSHIFT( rand_seed, 25 ) & RAND_BUF_MASK;
+
+ /* Unrolled loop */
+ LTP_pred_Q14 = silk_SMULWB( pred_lag_ptr[ 0 ], B_Q14[ 0 ] );
+ LTP_pred_Q14 = silk_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -1 ], B_Q14[ 1 ] );
+ LTP_pred_Q14 = silk_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -2 ], B_Q14[ 2 ] );
+ LTP_pred_Q14 = silk_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -3 ], B_Q14[ 3 ] );
+ LTP_pred_Q14 = silk_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -4 ], B_Q14[ 4 ] );
+ pred_lag_ptr++;
+
+ /* Generate LPC residual */
+ LPC_exc_Q10 = silk_LSHIFT( silk_SMULWB( rand_ptr[ idx ], rand_scale_Q14 ), 2 ); /* Random noise part */
+ LPC_exc_Q10 = silk_ADD32( LPC_exc_Q10, silk_RSHIFT_ROUND( LTP_pred_Q14, 4 ) ); /* Harmonic part */
+
+ /* Update states */
+ psDec->sLTP_Q16[ sLTP_buf_idx ] = silk_LSHIFT( LPC_exc_Q10, 6 );
+ sLTP_buf_idx++;
+
+ /* Save LPC residual */
+ sig_Q10_ptr[ i ] = LPC_exc_Q10;
+ }
+ sig_Q10_ptr += psDec->subfr_length;
+ /* Gradually reduce LTP gain */
+ for( j = 0; j < LTP_ORDER; j++ ) {
+ B_Q14[ j ] = silk_RSHIFT( silk_SMULBB( harm_Gain_Q15, B_Q14[ j ] ), 15 );
+ }
+ /* Gradually reduce excitation gain */
+ rand_scale_Q14 = silk_RSHIFT( silk_SMULBB( rand_scale_Q14, rand_Gain_Q15 ), 15 );
+
+ /* Slowly increase pitch lag */
+ psPLC->pitchL_Q8 += silk_SMULWB( psPLC->pitchL_Q8, PITCH_DRIFT_FAC_Q16 );
+ psPLC->pitchL_Q8 = silk_min_32( psPLC->pitchL_Q8, silk_LSHIFT( silk_SMULBB( MAX_PITCH_LAG_MS, psDec->fs_kHz ), 8 ) );
+ lag = silk_RSHIFT_ROUND( psPLC->pitchL_Q8, 8 );
+ }
+
+ /***************************/
+ /* LPC synthesis filtering */
+ /***************************/
+ sig_Q10_ptr = sig_Q10;
+ /* Preload LPC coeficients to array on stack. Gives small performance gain */
+ silk_memcpy( A_Q12_tmp, psPLC->prevLPC_Q12, psDec->LPC_order * sizeof( opus_int16 ) );
+ silk_assert( psDec->LPC_order >= 10 ); /* check that unrolling works */
+ for( k = 0; k < psDec->nb_subfr; k++ ) {
+ for( i = 0; i < psDec->subfr_length; i++ ){
+ /* partly unrolled */
+ LPC_pred_Q10 = silk_SMULWB( psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 1 ], A_Q12_tmp[ 0 ] );
+ LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 2 ], A_Q12_tmp[ 1 ] );
+ LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 3 ], A_Q12_tmp[ 2 ] );
+ LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 4 ], A_Q12_tmp[ 3 ] );
+ LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 5 ], A_Q12_tmp[ 4 ] );
+ LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 6 ], A_Q12_tmp[ 5 ] );
+ LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 7 ], A_Q12_tmp[ 6 ] );
+ LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 8 ], A_Q12_tmp[ 7 ] );
+ LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 9 ], A_Q12_tmp[ 8 ] );
+ LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 10 ], A_Q12_tmp[ 9 ] );
+
+ for( j = 10; j < psDec->LPC_order; j++ ) {
+ LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - j - 1 ], A_Q12_tmp[ j ] );
+ }
+
+ /* Add prediction to LPC residual */
+ sig_Q10_ptr[ i ] = silk_ADD32( sig_Q10_ptr[ i ], LPC_pred_Q10 );
+
+ /* Update states */
+ psDec->sLPC_Q14[ MAX_LPC_ORDER + i ] = silk_LSHIFT( sig_Q10_ptr[ i ], 4 );
+ }
+ sig_Q10_ptr += psDec->subfr_length;
+ /* Update LPC filter state */
+ silk_memcpy( psDec->sLPC_Q14, &psDec->sLPC_Q14[ psDec->subfr_length ], MAX_LPC_ORDER * sizeof( opus_int32 ) );
+ }
+
+ /* Scale with Gain */
+ for( i = 0; i < psDec->frame_length; i++ ) {
+ frame[ i ] = ( opus_int16 )silk_SAT16( silk_RSHIFT_ROUND( silk_SMULWW( sig_Q10[ i ], psPLC->prevGain_Q16[ psDec->nb_subfr - 1 ] ), 10 ) );
+ }
+
+ /**************************************/
+ /* Update states */
+ /**************************************/
+ psPLC->rand_seed = rand_seed;
+ psPLC->randScale_Q14 = rand_scale_Q14;
+ for( i = 0; i < MAX_NB_SUBFR; i++ ) {
+ psDecCtrl->pitchL[ i ] = lag;
+ }
+}
+
+/* Glues concealed frames with new good recieved frames */
+void silk_PLC_glue_frames(
+ silk_decoder_state *psDec, /* I/O decoder state */
+ silk_decoder_control *psDecCtrl, /* I/O Decoder control */
+ opus_int16 frame[], /* I/O signal */
+ opus_int length /* I length of residual */
+)
+{
+ opus_int i, energy_shift;
+ opus_int32 energy;
+ silk_PLC_struct *psPLC;
+ psPLC = &psDec->sPLC;
+
+ if( psDec->lossCnt ) {
+ /* Calculate energy in concealed residual */
+ silk_sum_sqr_shift( &psPLC->conc_energy, &psPLC->conc_energy_shift, frame, length );
+
+ psPLC->last_frame_lost = 1;
+ } else {
+ if( psDec->sPLC.last_frame_lost ) {
+ /* Calculate residual in decoded signal if last frame was lost */
+ silk_sum_sqr_shift( &energy, &energy_shift, frame, length );
+
+ /* Normalize energies */
+ if( energy_shift > psPLC->conc_energy_shift ) {
+ psPLC->conc_energy = silk_RSHIFT( psPLC->conc_energy, energy_shift - psPLC->conc_energy_shift );
+ } else if( energy_shift < psPLC->conc_energy_shift ) {
+ energy = silk_RSHIFT( energy, psPLC->conc_energy_shift - energy_shift );
+ }
+
+ /* Fade in the energy difference */
+ if( energy > psPLC->conc_energy ) {
+ opus_int32 frac_Q24, LZ;
+ opus_int32 gain_Q16, slope_Q16;
+
+ LZ = silk_CLZ32( psPLC->conc_energy );
+ LZ = LZ - 1;
+ psPLC->conc_energy = silk_LSHIFT( psPLC->conc_energy, LZ );
+ energy = silk_RSHIFT( energy, silk_max_32( 24 - LZ, 0 ) );
+
+ frac_Q24 = silk_DIV32( psPLC->conc_energy, silk_max( energy, 1 ) );
+
+ gain_Q16 = silk_LSHIFT( silk_SQRT_APPROX( frac_Q24 ), 4 );
+ slope_Q16 = silk_DIV32_16( ( 1 << 16 ) - gain_Q16, length );
+ /* Make slope 4x steeper to avoid missing onsets after DTX */
+ slope_Q16 = silk_LSHIFT( slope_Q16, 2 );
+
+ for( i = 0; i < length; i++ ) {
+ frame[ i ] = silk_SMULWB( gain_Q16, frame[ i ] );
+ gain_Q16 += slope_Q16;
+ if( gain_Q16 > 1 << 16 ) {
+ break;
+ }
+ }
+ }
+ }
+ psPLC->last_frame_lost = 0;
+ }
+}