/src/opus/silk/PLC.c

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/***********************************************************************
Copyright (c) 2006-2011, Skype Limited. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, 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 Internet Society, IETF or IETF Trust, nor the
names of specific contributors, may be used to endorse or promote
products derived from this software without specific prior written
permission.
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
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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 "stack_alloc.h"
#include "PLC.h"

#ifdef ENABLE_DEEP_PLC
#include "lpcnet.h"
#endif

#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 */

static OPUS_INLINE void silk_PLC_update(
    silk_decoder_state                  *psDec,             /* I/O Decoder state        */
    silk_decoder_control                *psDecCtrl          /* I/O Decoder control      */
);

static OPUS_INLINE void silk_PLC_conceal(
    silk_decoder_state                  *psDec,             /* I/O Decoder state        */
    silk_decoder_control                *psDecCtrl,         /* I/O Decoder control      */
    opus_int16                          frame[],            /* O LPC residual signal    */
#ifdef ENABLE_DEEP_PLC
    LPCNetPLCState                      *lpcnet,
#endif
    int                                 arch                /* I  Run-time architecture */
);


void silk_PLC_Reset(
    silk_decoder_state                  *psDec              /* I/O Decoder state        */
)
{
    psDec->sPLC.pitchL_Q8 = silk_LSHIFT( psDec->frame_length, 8 - 1 );
    psDec->sPLC.prevGain_Q16[ 0 ] = SILK_FIX_CONST( 1, 16 );
    psDec->sPLC.prevGain_Q16[ 1 ] = SILK_FIX_CONST( 1, 16 );
    psDec->sPLC.subfr_length = 20;
    psDec->sPLC.nb_subfr = 2;
}

void silk_PLC(
    silk_decoder_state                  *psDec,             /* I/O Decoder state        */
    silk_decoder_control                *psDecCtrl,         /* I/O Decoder control      */
    opus_int16                          frame[],            /* I/O  signal              */
    opus_int                            lost,               /* I Loss flag              */
#ifdef ENABLE_DEEP_PLC
    LPCNetPLCState                      *lpcnet,
#endif
    int                                 arch                /* I Run-time architecture  */
)
{
    /* 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,
#ifdef ENABLE_DEEP_PLC
            lpcnet,
#endif
            arch );

        psDec->lossCnt++;
    } else {
        /****************************/
        /* Update state             */
        /****************************/
        silk_PLC_update( psDec, psDecCtrl );
#ifdef ENABLE_DEEP_PLC
        if ( lpcnet != NULL && psDec->sPLC.fs_kHz == 16 ) {
            int k;
            for( k = 0; k < psDec->nb_subfr; k += 2 ) {
                lpcnet_plc_update( lpcnet, frame + k * psDec->subfr_length );
            }
        }
#endif
    }
}

/**************************************************/
/* Update state of PLC                            */
/**************************************************/
static OPUS_INLINE void silk_PLC_update(
    silk_decoder_state                  *psDec,             /* I/O Decoder state        */
    silk_decoder_control                *psDecCtrl          /* I/O Decoder control      */
)
{
    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 );
            }
        }

        silk_memset( psPLC->LTPCoef_Q14, 0, LTP_ORDER * sizeof( opus_int16 ) );
        psPLC->LTPCoef_Q14[ LTP_ORDER / 2 ] = LTP_Gain_Q14;

        /* 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 last two gains */
    silk_memcpy( psPLC->prevGain_Q16, &psDecCtrl->Gains_Q16[ psDec->nb_subfr - 2 ], 2 * sizeof( opus_int32 ) );

    psPLC->subfr_length = psDec->subfr_length;
    psPLC->nb_subfr = psDec->nb_subfr;
}

static OPUS_INLINE void silk_PLC_energy(opus_int32 *energy1, opus_int *shift1, opus_int32 *energy2, opus_int *shift2,
      const opus_int32 *exc_Q14, const opus_int32 *prevGain_Q10, int subfr_length, int nb_subfr)
{
    int i, k;
    VARDECL( opus_int16, exc_buf );
    opus_int16 *exc_buf_ptr;
    SAVE_STACK;
    ALLOC( exc_buf, 2*subfr_length, opus_int16 );
    /* Find random noise component */
    /* Scale previous excitation signal */
    exc_buf_ptr = exc_buf;
    for( k = 0; k < 2; k++ ) {
        for( i = 0; i < subfr_length; i++ ) {
            exc_buf_ptr[ i ] = (opus_int16)silk_SAT16( silk_RSHIFT(
                silk_SMULWW( exc_Q14[ i + ( k + nb_subfr - 2 ) * subfr_length ], prevGain_Q10[ k ] ), 8 ) );
        }
        exc_buf_ptr += 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,                  subfr_length );
    silk_sum_sqr_shift( energy2, shift2, &exc_buf[ subfr_length ], subfr_length );
    RESTORE_STACK;
}

static OPUS_INLINE void silk_PLC_conceal(
    silk_decoder_state                  *psDec,             /* I/O Decoder state        */
    silk_decoder_control                *psDecCtrl,         /* I/O Decoder control      */
    opus_int16                          frame[],            /* O LPC residual signal    */
#ifdef ENABLE_DEEP_PLC
    LPCNetPLCState                      *lpcnet,
#endif
    int                                 arch                /* I Run-time architecture  */
)
{
    opus_int   i, j, k;
    opus_int   lag, idx, sLTP_buf_idx, shift1, shift2;
    opus_int32 rand_seed, harm_Gain_Q15, rand_Gain_Q15, inv_gain_Q30;
    opus_int32 energy1, energy2, *rand_ptr, *pred_lag_ptr;
    opus_int32 LPC_pred_Q10, LTP_pred_Q12;
    opus_int16 rand_scale_Q14;
    opus_int16 *B_Q14;
    opus_int32 *sLPC_Q14_ptr;
    opus_int16 A_Q12[ MAX_LPC_ORDER ];
#ifdef SMALL_FOOTPRINT
    opus_int16 *sLTP;
#else
    VARDECL( opus_int16, sLTP );
#endif
    VARDECL( opus_int32, sLTP_Q14 );
    silk_PLC_struct *psPLC = &psDec->sPLC;
    opus_int32 prevGain_Q10[2];
    SAVE_STACK;

    ALLOC( sLTP_Q14, psDec->ltp_mem_length + psDec->frame_length, opus_int32 );
#ifdef SMALL_FOOTPRINT
    /* Ugly hack that breaks aliasing rules to save stack: put sLTP at the very end of sLTP_Q14. */
    sLTP = ((opus_int16*)&sLTP_Q14[psDec->ltp_mem_length + psDec->frame_length])-psDec->ltp_mem_length;
#else
    ALLOC( sLTP, psDec->ltp_mem_length, opus_int16 );
#endif

    prevGain_Q10[0] = silk_RSHIFT( psPLC->prevGain_Q16[ 0 ], 6);
    prevGain_Q10[1] = silk_RSHIFT( psPLC->prevGain_Q16[ 1 ], 6);

    if( psDec->first_frame_after_reset ) {
       silk_memset( psPLC->prevLPC_Q12, 0, sizeof( psPLC->prevLPC_Q12 ) );
    }

    silk_PLC_energy(&energy1, &shift1, &energy2, &shift2, psDec->exc_Q14, prevGain_Q10, psDec->subfr_length, psDec->nb_subfr);

    if( silk_RSHIFT( energy1, shift2 ) < silk_RSHIFT( energy2, shift1 ) ) {
        /* First sub-frame has lowest energy */
        rand_ptr = &psDec->exc_Q14[ silk_max_int( 0, ( psPLC->nb_subfr - 1 ) * psPLC->subfr_length - RAND_BUF_SIZE ) ];
    } else {
        /* Second sub-frame has lowest energy */
        rand_ptr = &psDec->exc_Q14[ silk_max_int( 0, psPLC->nb_subfr * psPLC->subfr_length - RAND_BUF_SIZE ) ];
    }

    /* Set up Gain to random noise component */
    B_Q14          = psPLC->LTPCoef_Q14;
    rand_scale_Q14 = psPLC->randScale_Q14;

    /* Set up 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 ) ];
    }

    /* LPC concealment. Apply BWE to previous LPC */
    silk_bwexpander( psPLC->prevLPC_Q12, psDec->LPC_order, SILK_FIX_CONST( BWE_COEF, 16 ) );

    /* Preload LPC coeficients to array on stack. Gives small performance gain */
    silk_memcpy( A_Q12, psPLC->prevLPC_Q12, psDec->LPC_order * sizeof( opus_int16 ) );

    /* 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;

            invGain_Q30 = silk_LPC_inverse_pred_gain( psPLC->prevLPC_Q12, psDec->LPC_order, arch );

            down_scale_Q30 = silk_min_32( silk_RSHIFT( (opus_int32)1 << 30, LOG2_INV_LPC_GAIN_HIGH_THRES ), invGain_Q30 );
            down_scale_Q30 = silk_max_32( silk_RSHIFT( (opus_int32)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;

    /* Rewhiten LTP state */
    idx = psDec->ltp_mem_length - lag - psDec->LPC_order - LTP_ORDER / 2;
    celt_assert( idx > 0 );
    silk_LPC_analysis_filter( &sLTP[ idx ], &psDec->outBuf[ idx ], A_Q12, psDec->ltp_mem_length - idx, psDec->LPC_order, arch );
    /* Scale LTP state */
    inv_gain_Q30 = silk_INVERSE32_varQ( psPLC->prevGain_Q16[ 1 ], 46 );
    inv_gain_Q30 = silk_min( inv_gain_Q30, silk_int32_MAX >> 1 );
    for( i = idx + psDec->LPC_order; i < psDec->ltp_mem_length; i++ ) {
        sLTP_Q14[ i ] = silk_SMULWB( inv_gain_Q30, sLTP[ i ] );
    }

    /***************************/
    /* LTP synthesis filtering */
    /***************************/
    for( k = 0; k < psDec->nb_subfr; k++ ) {
        /* Set up pointer */
        pred_lag_ptr = &sLTP_Q14[ sLTP_buf_idx - lag + LTP_ORDER / 2 ];
        for( i = 0; i < psDec->subfr_length; i++ ) {
            /* Unrolled loop */
            /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
            LTP_pred_Q12 = 2;
            LTP_pred_Q12 = silk_SMLAWB( LTP_pred_Q12, pred_lag_ptr[  0 ], B_Q14[ 0 ] );
            LTP_pred_Q12 = silk_SMLAWB( LTP_pred_Q12, pred_lag_ptr[ -1 ], B_Q14[ 1 ] );
            LTP_pred_Q12 = silk_SMLAWB( LTP_pred_Q12, pred_lag_ptr[ -2 ], B_Q14[ 2 ] );
            LTP_pred_Q12 = silk_SMLAWB( LTP_pred_Q12, pred_lag_ptr[ -3 ], B_Q14[ 3 ] );
            LTP_pred_Q12 = silk_SMLAWB( LTP_pred_Q12, pred_lag_ptr[ -4 ], B_Q14[ 4 ] );
            pred_lag_ptr++;

            /* Generate LPC excitation */
            rand_seed = silk_RAND( rand_seed );
            idx = silk_RSHIFT( rand_seed, 25 ) & RAND_BUF_MASK;
            sLTP_Q14[ sLTP_buf_idx ] = silk_LSHIFT32( silk_SMLAWB( LTP_pred_Q12, rand_ptr[ idx ], rand_scale_Q14 ), 2 );
            sLTP_buf_idx++;
        }

        /* 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_SMLAWB( psPLC->pitchL_Q8, 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 */
    /***************************/
    sLPC_Q14_ptr = &sLTP_Q14[ psDec->ltp_mem_length - MAX_LPC_ORDER ];

    /* Copy LPC state */
    silk_memcpy( sLPC_Q14_ptr, psDec->sLPC_Q14_buf, MAX_LPC_ORDER * sizeof( opus_int32 ) );

    celt_assert( psDec->LPC_order >= 10 ); /* check that unrolling works */
    for( i = 0; i < psDec->frame_length; i++ ) {
        /* partly unrolled */
        /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
        LPC_pred_Q10 = silk_RSHIFT( psDec->LPC_order, 1 );
        LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i -  1 ], A_Q12[ 0 ] );
        LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i -  2 ], A_Q12[ 1 ] );
        LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i -  3 ], A_Q12[ 2 ] );
        LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i -  4 ], A_Q12[ 3 ] );
        LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i -  5 ], A_Q12[ 4 ] );
        LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i -  6 ], A_Q12[ 5 ] );
        LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i -  7 ], A_Q12[ 6 ] );
        LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i -  8 ], A_Q12[ 7 ] );
        LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i -  9 ], A_Q12[ 8 ] );
        LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i - 10 ], A_Q12[ 9 ] );
        for( j = 10; j < psDec->LPC_order; j++ ) {
            LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i - j - 1 ], A_Q12[ j ] );
        }

        /* Add prediction to LPC excitation */
        sLPC_Q14_ptr[ MAX_LPC_ORDER + i ] = silk_ADD_SAT32( sLPC_Q14_ptr[ MAX_LPC_ORDER + i ],
                                            silk_LSHIFT_SAT32( LPC_pred_Q10, 4 ));

        /* Scale with Gain */
        frame[ i ] = (opus_int16)silk_SAT16( silk_SAT16( silk_RSHIFT_ROUND( silk_SMULWW( sLPC_Q14_ptr[ MAX_LPC_ORDER + i ], prevGain_Q10[ 1 ] ), 8 ) ) );
    }
#ifdef ENABLE_DEEP_PLC
    if ( lpcnet != NULL && lpcnet->loaded && psDec->sPLC.fs_kHz == 16 ) {
        int run_deep_plc = psDec->sPLC.enable_deep_plc || lpcnet->fec_fill_pos != 0;
        if( run_deep_plc ) {
            for( k = 0; k < psDec->nb_subfr; k += 2 ) {
                lpcnet_plc_conceal( lpcnet, frame + k * psDec->subfr_length );
            }
            /* We *should* be able to copy only from psDec->frame_length-MAX_LPC_ORDER, i.e. the last MAX_LPC_ORDER samples. */
            for( i = 0; i < psDec->frame_length; i++ ) {
                sLPC_Q14_ptr[ MAX_LPC_ORDER + i ] = (int)floor(.5 + frame[ i ] * (float)(1 << 24) / prevGain_Q10[ 1 ] );
            }
        } else {
          for( k = 0; k < psDec->nb_subfr; k += 2 ) {
              lpcnet_plc_update( lpcnet, frame + k * psDec->subfr_length );
          }
        }
    }
#endif

    /* Save LPC state */
    silk_memcpy( psDec->sLPC_Q14_buf, &sLPC_Q14_ptr[ psDec->frame_length ], MAX_LPC_ORDER * sizeof( opus_int32 ) );

    /**************************************/
    /* 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;
    }
    RESTORE_STACK;
}

/* Glues concealed frames with new good received frames */
void silk_PLC_glue_frames(
    silk_decoder_state                  *psDec,             /* I/O decoder state        */
    opus_int16                          frame[],            /* I/O signal               */
    opus_int                            length              /* I length of signal       */
)
{
    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( ( (opus_int32)1 << 16 ) - gain_Q16, length );
                /* Make slope 4x steeper to avoid missing onsets after DTX */
                slope_Q16 = silk_LSHIFT( slope_Q16, 2 );
#ifdef ENABLE_DEEP_PLC
                if ( psDec->sPLC.fs_kHz != 16 )
#endif
                {
                    for( i = 0; i < length; i++ ) {
                        frame[ i ] = silk_SMULWB( gain_Q16, frame[ i ] );
                        gain_Q16 += slope_Q16;
                        if( gain_Q16 > (opus_int32)1 << 16 ) {
                            break;
                        }
                    }
                }
            }
        }
        psPLC->last_frame_lost = 0;
    }
}

Coverage Report

Created: 2024-09-06 07:53

Line	Count	Source (jump to first uncovered line)
1		/***********************************************************************
2		Copyright (c) 2006-2011, Skype Limited. All rights reserved.
3		Redistribution and use in source and binary forms, with or without
4		modification, are permitted provided that the following conditions
5		are met:
6		- Redistributions of source code must retain the above copyright notice,
7		this list of conditions and the following disclaimer.
8		- Redistributions in binary form must reproduce the above copyright
9		notice, this list of conditions and the following disclaimer in the
10		documentation and/or other materials provided with the distribution.
11		- Neither the name of Internet Society, IETF or IETF Trust, nor the
12		names of specific contributors, may be used to endorse or promote
13		products derived from this software without specific prior written
14		permission.
15		THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16		AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17		IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18		ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
19		LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20		CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21		SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22		INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23		CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24		ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25		POSSIBILITY OF SUCH DAMAGE.
26		***********************************************************************/
27
28		#ifdef HAVE_CONFIG_H
29		#include "config.h"
30		#endif
31
32		#include "main.h"
33		#include "stack_alloc.h"
34		#include "PLC.h"
35
36		#ifdef ENABLE_DEEP_PLC
37		#include "lpcnet.h"
38		#endif
39
40	0	#define NB_ATT 2
41		static const opus_int16 HARM_ATT_Q15[NB_ATT] = { 32440, 31130 }; /* 0.99, 0.95 */
42		static const opus_int16 PLC_RAND_ATTENUATE_V_Q15[NB_ATT] = { 31130, 26214 }; /* 0.95, 0.8 */
43		static const opus_int16 PLC_RAND_ATTENUATE_UV_Q15[NB_ATT] = { 32440, 29491 }; /* 0.99, 0.9 */
44
45		static OPUS_INLINE void silk_PLC_update(
46		silk_decoder_state psDec, / I/O Decoder state */
47		silk_decoder_control psDecCtrl / I/O Decoder control */
48		);
49
50		static OPUS_INLINE void silk_PLC_conceal(
51		silk_decoder_state psDec, / I/O Decoder state */
52		silk_decoder_control psDecCtrl, / I/O Decoder control */
53		opus_int16 frame[], /* O LPC residual signal */
54		#ifdef ENABLE_DEEP_PLC
55		LPCNetPLCState *lpcnet,
56		#endif
57		int arch /* I Run-time architecture */
58		);
59
60
61		void silk_PLC_Reset(
62		silk_decoder_state psDec / I/O Decoder state */
63		)
64	0	{
65	0	psDec->sPLC.pitchL_Q8 = silk_LSHIFT( psDec->frame_length, 8 - 1 );
66	0	psDec->sPLC.prevGain_Q16[ 0 ] = SILK_FIX_CONST( 1, 16 );
67	0	psDec->sPLC.prevGain_Q16[ 1 ] = SILK_FIX_CONST( 1, 16 );
68	0	psDec->sPLC.subfr_length = 20;
69	0	psDec->sPLC.nb_subfr = 2;
70	0	}
71
72		void silk_PLC(
73		silk_decoder_state psDec, / I/O Decoder state */
74		silk_decoder_control psDecCtrl, / I/O Decoder control */
75		opus_int16 frame[], /* I/O signal */
76		opus_int lost, /* I Loss flag */
77		#ifdef ENABLE_DEEP_PLC
78		LPCNetPLCState *lpcnet,
79		#endif
80		int arch /* I Run-time architecture */
81		)
82	0	{
83		/* PLC control function */
84	0	if( psDec->fs_kHz != psDec->sPLC.fs_kHz ) {
85	0	silk_PLC_Reset( psDec );
86	0	psDec->sPLC.fs_kHz = psDec->fs_kHz;
87	0	}
88
89	0	if( lost ) {
90		/****************************/
91		/* Generate Signal */
92		/****************************/
93	0	silk_PLC_conceal( psDec, psDecCtrl, frame,
94		#ifdef ENABLE_DEEP_PLC
95		lpcnet,
96		#endif
97	0	arch );
98
99	0	psDec->lossCnt++;
100	0	} else {
101		/****************************/
102		/* Update state */
103		/****************************/
104	0	silk_PLC_update( psDec, psDecCtrl );
105		#ifdef ENABLE_DEEP_PLC
106		if ( lpcnet != NULL && psDec->sPLC.fs_kHz == 16 ) {
107		int k;
108		for( k = 0; k < psDec->nb_subfr; k += 2 ) {
109		lpcnet_plc_update( lpcnet, frame + k * psDec->subfr_length );
110		}
111		}
112		#endif
113	0	}
114	0	}
115
116		/**************************************************/
117		/* Update state of PLC */
118		/**************************************************/
119		static OPUS_INLINE void silk_PLC_update(
120		silk_decoder_state psDec, / I/O Decoder state */
121		silk_decoder_control psDecCtrl / I/O Decoder control */
122		)
123	0	{
124	0	opus_int32 LTP_Gain_Q14, temp_LTP_Gain_Q14;
125	0	opus_int i, j;
126	0	silk_PLC_struct *psPLC;
127
128	0	psPLC = &psDec->sPLC;
129
130		/* Update parameters used in case of packet loss */
131	0	psDec->prevSignalType = psDec->indices.signalType;
132	0	LTP_Gain_Q14 = 0;
133	0	if( psDec->indices.signalType == TYPE_VOICED ) {
134		/* Find the parameters for the last subframe which contains a pitch pulse */
135	0	for( j = 0; j * psDec->subfr_length < psDecCtrl->pitchL[ psDec->nb_subfr - 1 ]; j++ ) {
136	0	if( j == psDec->nb_subfr ) {
137	0	break;
138	0	}
139	0	temp_LTP_Gain_Q14 = 0;
140	0	for( i = 0; i < LTP_ORDER; i++ ) {
141	0	temp_LTP_Gain_Q14 += psDecCtrl->LTPCoef_Q14[ ( psDec->nb_subfr - 1 - j ) * LTP_ORDER + i ];
142	0	}
143	0	if( temp_LTP_Gain_Q14 > LTP_Gain_Q14 ) {
144	0	LTP_Gain_Q14 = temp_LTP_Gain_Q14;
145	0	silk_memcpy( psPLC->LTPCoef_Q14,
146	0	&psDecCtrl->LTPCoef_Q14[ silk_SMULBB( psDec->nb_subfr - 1 - j, LTP_ORDER ) ],
147	0	LTP_ORDER * sizeof( opus_int16 ) );
148
149	0	psPLC->pitchL_Q8 = silk_LSHIFT( psDecCtrl->pitchL[ psDec->nb_subfr - 1 - j ], 8 );
150	0	}
151	0	}
152
153	0	silk_memset( psPLC->LTPCoef_Q14, 0, LTP_ORDER * sizeof( opus_int16 ) );
154	0	psPLC->LTPCoef_Q14[ LTP_ORDER / 2 ] = LTP_Gain_Q14;
155
156		/* Limit LT coefs */
157	0	if( LTP_Gain_Q14 < V_PITCH_GAIN_START_MIN_Q14 ) {
158	0	opus_int scale_Q10;
159	0	opus_int32 tmp;
160
161	0	tmp = silk_LSHIFT( V_PITCH_GAIN_START_MIN_Q14, 10 );
162	0	scale_Q10 = silk_DIV32( tmp, silk_max( LTP_Gain_Q14, 1 ) );
163	0	for( i = 0; i < LTP_ORDER; i++ ) {
164	0	psPLC->LTPCoef_Q14[ i ] = silk_RSHIFT( silk_SMULBB( psPLC->LTPCoef_Q14[ i ], scale_Q10 ), 10 );
165	0	}
166	0	} else if( LTP_Gain_Q14 > V_PITCH_GAIN_START_MAX_Q14 ) {
167	0	opus_int scale_Q14;
168	0	opus_int32 tmp;
169
170	0	tmp = silk_LSHIFT( V_PITCH_GAIN_START_MAX_Q14, 14 );
171	0	scale_Q14 = silk_DIV32( tmp, silk_max( LTP_Gain_Q14, 1 ) );
172	0	for( i = 0; i < LTP_ORDER; i++ ) {
173	0	psPLC->LTPCoef_Q14[ i ] = silk_RSHIFT( silk_SMULBB( psPLC->LTPCoef_Q14[ i ], scale_Q14 ), 14 );
174	0	}
175	0	}
176	0	} else {
177	0	psPLC->pitchL_Q8 = silk_LSHIFT( silk_SMULBB( psDec->fs_kHz, 18 ), 8 );
178	0	silk_memset( psPLC->LTPCoef_Q14, 0, LTP_ORDER * sizeof( opus_int16 ));
179	0	}
180
181		/* Save LPC coeficients */
182	0	silk_memcpy( psPLC->prevLPC_Q12, psDecCtrl->PredCoef_Q12[ 1 ], psDec->LPC_order * sizeof( opus_int16 ) );
183	0	psPLC->prevLTP_scale_Q14 = psDecCtrl->LTP_scale_Q14;
184
185		/* Save last two gains */
186	0	silk_memcpy( psPLC->prevGain_Q16, &psDecCtrl->Gains_Q16[ psDec->nb_subfr - 2 ], 2 * sizeof( opus_int32 ) );
187
188	0	psPLC->subfr_length = psDec->subfr_length;
189	0	psPLC->nb_subfr = psDec->nb_subfr;
190	0	}
191
192		static OPUS_INLINE void silk_PLC_energy(opus_int32 energy1, opus_int shift1, opus_int32 energy2, opus_int shift2,
193		const opus_int32 exc_Q14, const opus_int32 prevGain_Q10, int subfr_length, int nb_subfr)
194	0	{
195	0	int i, k;
196	0	VARDECL( opus_int16, exc_buf );
197	0	opus_int16 *exc_buf_ptr;
198	0	SAVE_STACK;
199	0	ALLOC( exc_buf, 2*subfr_length, opus_int16 );
200		/* Find random noise component */
201		/* Scale previous excitation signal */
202	0	exc_buf_ptr = exc_buf;
203	0	for( k = 0; k < 2; k++ ) {
204	0	for( i = 0; i < subfr_length; i++ ) {
205	0	exc_buf_ptr[ i ] = (opus_int16)silk_SAT16( silk_RSHIFT(
206	0	silk_SMULWW( exc_Q14[ i + ( k + nb_subfr - 2 ) * subfr_length ], prevGain_Q10[ k ] ), 8 ) );
207	0	}
208	0	exc_buf_ptr += subfr_length;
209	0	}
210		/* Find the subframe with lowest energy of the last two and use that as random noise generator */
211	0	silk_sum_sqr_shift( energy1, shift1, exc_buf, subfr_length );
212	0	silk_sum_sqr_shift( energy2, shift2, &exc_buf[ subfr_length ], subfr_length );
213	0	RESTORE_STACK;
214	0	}
215
216		static OPUS_INLINE void silk_PLC_conceal(
217		silk_decoder_state psDec, / I/O Decoder state */
218		silk_decoder_control psDecCtrl, / I/O Decoder control */
219		opus_int16 frame[], /* O LPC residual signal */
220		#ifdef ENABLE_DEEP_PLC
221		LPCNetPLCState *lpcnet,
222		#endif
223		int arch /* I Run-time architecture */
224		)
225	0	{
226	0	opus_int i, j, k;
227	0	opus_int lag, idx, sLTP_buf_idx, shift1, shift2;
228	0	opus_int32 rand_seed, harm_Gain_Q15, rand_Gain_Q15, inv_gain_Q30;
229	0	opus_int32 energy1, energy2, rand_ptr, pred_lag_ptr;
230	0	opus_int32 LPC_pred_Q10, LTP_pred_Q12;
231	0	opus_int16 rand_scale_Q14;
232	0	opus_int16 *B_Q14;
233	0	opus_int32 *sLPC_Q14_ptr;
234	0	opus_int16 A_Q12[ MAX_LPC_ORDER ];
235		#ifdef SMALL_FOOTPRINT
236		opus_int16 *sLTP;
237		#else
238	0	VARDECL( opus_int16, sLTP );
239	0	#endif
240	0	VARDECL( opus_int32, sLTP_Q14 );
241	0	silk_PLC_struct *psPLC = &psDec->sPLC;
242	0	opus_int32 prevGain_Q10[2];
243	0	SAVE_STACK;
244
245	0	ALLOC( sLTP_Q14, psDec->ltp_mem_length + psDec->frame_length, opus_int32 );
246		#ifdef SMALL_FOOTPRINT
247		/* Ugly hack that breaks aliasing rules to save stack: put sLTP at the very end of sLTP_Q14. */
248		sLTP = ((opus_int16*)&sLTP_Q14[psDec->ltp_mem_length + psDec->frame_length])-psDec->ltp_mem_length;
249		#else
250	0	ALLOC( sLTP, psDec->ltp_mem_length, opus_int16 );
251	0	#endif
252
253	0	prevGain_Q10[0] = silk_RSHIFT( psPLC->prevGain_Q16[ 0 ], 6);
254	0	prevGain_Q10[1] = silk_RSHIFT( psPLC->prevGain_Q16[ 1 ], 6);
255
256	0	if( psDec->first_frame_after_reset ) {
257	0	silk_memset( psPLC->prevLPC_Q12, 0, sizeof( psPLC->prevLPC_Q12 ) );
258	0	}
259
260	0	silk_PLC_energy(&energy1, &shift1, &energy2, &shift2, psDec->exc_Q14, prevGain_Q10, psDec->subfr_length, psDec->nb_subfr);
261
262	0	if( silk_RSHIFT( energy1, shift2 ) < silk_RSHIFT( energy2, shift1 ) ) {
263		/* First sub-frame has lowest energy */
264	0	rand_ptr = &psDec->exc_Q14[ silk_max_int( 0, ( psPLC->nb_subfr - 1 ) * psPLC->subfr_length - RAND_BUF_SIZE ) ];
265	0	} else {
266		/* Second sub-frame has lowest energy */
267	0	rand_ptr = &psDec->exc_Q14[ silk_max_int( 0, psPLC->nb_subfr * psPLC->subfr_length - RAND_BUF_SIZE ) ];
268	0	}
269
270		/* Set up Gain to random noise component */
271	0	B_Q14 = psPLC->LTPCoef_Q14;
272	0	rand_scale_Q14 = psPLC->randScale_Q14;
273
274		/* Set up attenuation gains */
275	0	harm_Gain_Q15 = HARM_ATT_Q15[ silk_min_int( NB_ATT - 1, psDec->lossCnt ) ];
276	0	if( psDec->prevSignalType == TYPE_VOICED ) {
277	0	rand_Gain_Q15 = PLC_RAND_ATTENUATE_V_Q15[ silk_min_int( NB_ATT - 1, psDec->lossCnt ) ];
278	0	} else {
279	0	rand_Gain_Q15 = PLC_RAND_ATTENUATE_UV_Q15[ silk_min_int( NB_ATT - 1, psDec->lossCnt ) ];
280	0	}
281
282		/* LPC concealment. Apply BWE to previous LPC */
283	0	silk_bwexpander( psPLC->prevLPC_Q12, psDec->LPC_order, SILK_FIX_CONST( BWE_COEF, 16 ) );
284
285		/* Preload LPC coeficients to array on stack. Gives small performance gain */
286	0	silk_memcpy( A_Q12, psPLC->prevLPC_Q12, psDec->LPC_order * sizeof( opus_int16 ) );
287
288		/* First Lost frame */
289	0	if( psDec->lossCnt == 0 ) {
290	0	rand_scale_Q14 = 1 << 14;
291
292		/* Reduce random noise Gain for voiced frames */
293	0	if( psDec->prevSignalType == TYPE_VOICED ) {
294	0	for( i = 0; i < LTP_ORDER; i++ ) {
295	0	rand_scale_Q14 -= B_Q14[ i ];
296	0	}
297	0	rand_scale_Q14 = silk_max_16( 3277, rand_scale_Q14 ); /* 0.2 */
298	0	rand_scale_Q14 = (opus_int16)silk_RSHIFT( silk_SMULBB( rand_scale_Q14, psPLC->prevLTP_scale_Q14 ), 14 );
299	0	} else {
300		/* Reduce random noise for unvoiced frames with high LPC gain */
301	0	opus_int32 invGain_Q30, down_scale_Q30;
302
303	0	invGain_Q30 = silk_LPC_inverse_pred_gain( psPLC->prevLPC_Q12, psDec->LPC_order, arch );
304
305	0	down_scale_Q30 = silk_min_32( silk_RSHIFT( (opus_int32)1 << 30, LOG2_INV_LPC_GAIN_HIGH_THRES ), invGain_Q30 );
306	0	down_scale_Q30 = silk_max_32( silk_RSHIFT( (opus_int32)1 << 30, LOG2_INV_LPC_GAIN_LOW_THRES ), down_scale_Q30 );
307	0	down_scale_Q30 = silk_LSHIFT( down_scale_Q30, LOG2_INV_LPC_GAIN_HIGH_THRES );
308
309	0	rand_Gain_Q15 = silk_RSHIFT( silk_SMULWB( down_scale_Q30, rand_Gain_Q15 ), 14 );
310	0	}
311	0	}
312
313	0	rand_seed = psPLC->rand_seed;
314	0	lag = silk_RSHIFT_ROUND( psPLC->pitchL_Q8, 8 );
315	0	sLTP_buf_idx = psDec->ltp_mem_length;
316
317		/* Rewhiten LTP state */
318	0	idx = psDec->ltp_mem_length - lag - psDec->LPC_order - LTP_ORDER / 2;
319	0	celt_assert( idx > 0 );
320	0	silk_LPC_analysis_filter( &sLTP[ idx ], &psDec->outBuf[ idx ], A_Q12, psDec->ltp_mem_length - idx, psDec->LPC_order, arch );
321		/* Scale LTP state */
322	0	inv_gain_Q30 = silk_INVERSE32_varQ( psPLC->prevGain_Q16[ 1 ], 46 );
323	0	inv_gain_Q30 = silk_min( inv_gain_Q30, silk_int32_MAX >> 1 );
324	0	for( i = idx + psDec->LPC_order; i < psDec->ltp_mem_length; i++ ) {
325	0	sLTP_Q14[ i ] = silk_SMULWB( inv_gain_Q30, sLTP[ i ] );
326	0	}
327
328		/***************************/
329		/* LTP synthesis filtering */
330		/***************************/
331	0	for( k = 0; k < psDec->nb_subfr; k++ ) {
332		/* Set up pointer */
333	0	pred_lag_ptr = &sLTP_Q14[ sLTP_buf_idx - lag + LTP_ORDER / 2 ];
334	0	for( i = 0; i < psDec->subfr_length; i++ ) {
335		/* Unrolled loop */
336		/* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
337	0	LTP_pred_Q12 = 2;
338	0	LTP_pred_Q12 = silk_SMLAWB( LTP_pred_Q12, pred_lag_ptr[ 0 ], B_Q14[ 0 ] );
339	0	LTP_pred_Q12 = silk_SMLAWB( LTP_pred_Q12, pred_lag_ptr[ -1 ], B_Q14[ 1 ] );
340	0	LTP_pred_Q12 = silk_SMLAWB( LTP_pred_Q12, pred_lag_ptr[ -2 ], B_Q14[ 2 ] );
341	0	LTP_pred_Q12 = silk_SMLAWB( LTP_pred_Q12, pred_lag_ptr[ -3 ], B_Q14[ 3 ] );
342	0	LTP_pred_Q12 = silk_SMLAWB( LTP_pred_Q12, pred_lag_ptr[ -4 ], B_Q14[ 4 ] );
343	0	pred_lag_ptr++;
344
345		/* Generate LPC excitation */
346	0	rand_seed = silk_RAND( rand_seed );
347	0	idx = silk_RSHIFT( rand_seed, 25 ) & RAND_BUF_MASK;
348	0	sLTP_Q14[ sLTP_buf_idx ] = silk_LSHIFT32( silk_SMLAWB( LTP_pred_Q12, rand_ptr[ idx ], rand_scale_Q14 ), 2 );
349	0	sLTP_buf_idx++;
350	0	}
351
352		/* Gradually reduce LTP gain */
353	0	for( j = 0; j < LTP_ORDER; j++ ) {
354	0	B_Q14[ j ] = silk_RSHIFT( silk_SMULBB( harm_Gain_Q15, B_Q14[ j ] ), 15 );
355	0	}
356		/* Gradually reduce excitation gain */
357	0	rand_scale_Q14 = silk_RSHIFT( silk_SMULBB( rand_scale_Q14, rand_Gain_Q15 ), 15 );
358
359		/* Slowly increase pitch lag */
360	0	psPLC->pitchL_Q8 = silk_SMLAWB( psPLC->pitchL_Q8, psPLC->pitchL_Q8, PITCH_DRIFT_FAC_Q16 );
361	0	psPLC->pitchL_Q8 = silk_min_32( psPLC->pitchL_Q8, silk_LSHIFT( silk_SMULBB( MAX_PITCH_LAG_MS, psDec->fs_kHz ), 8 ) );
362	0	lag = silk_RSHIFT_ROUND( psPLC->pitchL_Q8, 8 );
363	0	}
364
365		/***************************/
366		/* LPC synthesis filtering */
367		/***************************/
368	0	sLPC_Q14_ptr = &sLTP_Q14[ psDec->ltp_mem_length - MAX_LPC_ORDER ];
369
370		/* Copy LPC state */
371	0	silk_memcpy( sLPC_Q14_ptr, psDec->sLPC_Q14_buf, MAX_LPC_ORDER * sizeof( opus_int32 ) );
372
373	0	celt_assert( psDec->LPC_order >= 10 ); /* check that unrolling works */
374	0	for( i = 0; i < psDec->frame_length; i++ ) {
375		/* partly unrolled */
376		/* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
377	0	LPC_pred_Q10 = silk_RSHIFT( psDec->LPC_order, 1 );
378	0	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i - 1 ], A_Q12[ 0 ] );
379	0	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i - 2 ], A_Q12[ 1 ] );
380	0	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i - 3 ], A_Q12[ 2 ] );
381	0	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i - 4 ], A_Q12[ 3 ] );
382	0	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i - 5 ], A_Q12[ 4 ] );
383	0	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i - 6 ], A_Q12[ 5 ] );
384	0	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i - 7 ], A_Q12[ 6 ] );
385	0	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i - 8 ], A_Q12[ 7 ] );
386	0	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i - 9 ], A_Q12[ 8 ] );
387	0	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i - 10 ], A_Q12[ 9 ] );
388	0	for( j = 10; j < psDec->LPC_order; j++ ) {
389	0	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14_ptr[ MAX_LPC_ORDER + i - j - 1 ], A_Q12[ j ] );
390	0	}
391
392		/* Add prediction to LPC excitation */
393	0	sLPC_Q14_ptr[ MAX_LPC_ORDER + i ] = silk_ADD_SAT32( sLPC_Q14_ptr[ MAX_LPC_ORDER + i ],
394	0	silk_LSHIFT_SAT32( LPC_pred_Q10, 4 ));
395
396		/* Scale with Gain */
397	0	frame[ i ] = (opus_int16)silk_SAT16( silk_SAT16( silk_RSHIFT_ROUND( silk_SMULWW( sLPC_Q14_ptr[ MAX_LPC_ORDER + i ], prevGain_Q10[ 1 ] ), 8 ) ) );
398	0	}
399		#ifdef ENABLE_DEEP_PLC
400		if ( lpcnet != NULL && lpcnet->loaded && psDec->sPLC.fs_kHz == 16 ) {
401		int run_deep_plc = psDec->sPLC.enable_deep_plc \|\| lpcnet->fec_fill_pos != 0;
402		if( run_deep_plc ) {
403		for( k = 0; k < psDec->nb_subfr; k += 2 ) {
404		lpcnet_plc_conceal( lpcnet, frame + k * psDec->subfr_length );
405		}
406		/* We should be able to copy only from psDec->frame_length-MAX_LPC_ORDER, i.e. the last MAX_LPC_ORDER samples. */
407		for( i = 0; i < psDec->frame_length; i++ ) {
408		sLPC_Q14_ptr[ MAX_LPC_ORDER + i ] = (int)floor(.5 + frame[ i ] * (float)(1 << 24) / prevGain_Q10[ 1 ] );
409		}
410		} else {
411		for( k = 0; k < psDec->nb_subfr; k += 2 ) {
412		lpcnet_plc_update( lpcnet, frame + k * psDec->subfr_length );
413		}
414		}
415		}
416		#endif
417
418		/* Save LPC state */
419	0	silk_memcpy( psDec->sLPC_Q14_buf, &sLPC_Q14_ptr[ psDec->frame_length ], MAX_LPC_ORDER * sizeof( opus_int32 ) );
420
421		/**************************************/
422		/* Update states */
423		/**************************************/
424	0	psPLC->rand_seed = rand_seed;
425	0	psPLC->randScale_Q14 = rand_scale_Q14;
426	0	for( i = 0; i < MAX_NB_SUBFR; i++ ) {
427	0	psDecCtrl->pitchL[ i ] = lag;
428	0	}
429	0	RESTORE_STACK;
430	0	}
431
432		/* Glues concealed frames with new good received frames */
433		void silk_PLC_glue_frames(
434		silk_decoder_state psDec, / I/O decoder state */
435		opus_int16 frame[], /* I/O signal */
436		opus_int length /* I length of signal */
437		)
438	0	{
439	0	opus_int i, energy_shift;
440	0	opus_int32 energy;
441	0	silk_PLC_struct *psPLC;
442	0	psPLC = &psDec->sPLC;
443
444	0	if( psDec->lossCnt ) {
445		/* Calculate energy in concealed residual */
446	0	silk_sum_sqr_shift( &psPLC->conc_energy, &psPLC->conc_energy_shift, frame, length );
447
448	0	psPLC->last_frame_lost = 1;
449	0	} else {
450	0	if( psDec->sPLC.last_frame_lost ) {
451		/* Calculate residual in decoded signal if last frame was lost */
452	0	silk_sum_sqr_shift( &energy, &energy_shift, frame, length );
453
454		/* Normalize energies */
455	0	if( energy_shift > psPLC->conc_energy_shift ) {
456	0	psPLC->conc_energy = silk_RSHIFT( psPLC->conc_energy, energy_shift - psPLC->conc_energy_shift );
457	0	} else if( energy_shift < psPLC->conc_energy_shift ) {
458	0	energy = silk_RSHIFT( energy, psPLC->conc_energy_shift - energy_shift );
459	0	}
460
461		/* Fade in the energy difference */
462	0	if( energy > psPLC->conc_energy ) {
463	0	opus_int32 frac_Q24, LZ;
464	0	opus_int32 gain_Q16, slope_Q16;
465
466	0	LZ = silk_CLZ32( psPLC->conc_energy );
467	0	LZ = LZ - 1;
468	0	psPLC->conc_energy = silk_LSHIFT( psPLC->conc_energy, LZ );
469	0	energy = silk_RSHIFT( energy, silk_max_32( 24 - LZ, 0 ) );
470
471	0	frac_Q24 = silk_DIV32( psPLC->conc_energy, silk_max( energy, 1 ) );
472
473	0	gain_Q16 = silk_LSHIFT( silk_SQRT_APPROX( frac_Q24 ), 4 );
474	0	slope_Q16 = silk_DIV32_16( ( (opus_int32)1 << 16 ) - gain_Q16, length );
475		/* Make slope 4x steeper to avoid missing onsets after DTX */
476	0	slope_Q16 = silk_LSHIFT( slope_Q16, 2 );
477		#ifdef ENABLE_DEEP_PLC
478		if ( psDec->sPLC.fs_kHz != 16 )
479		#endif
480	0	{
481	0	for( i = 0; i < length; i++ ) {
482	0	frame[ i ] = silk_SMULWB( gain_Q16, frame[ i ] );
483	0	gain_Q16 += slope_Q16;
484	0	if( gain_Q16 > (opus_int32)1 << 16 ) {
485	0	break;
486	0	}
487	0	}
488	0	}
489	0	}
490	0	}
491	0	psPLC->last_frame_lost = 0;
492	0	}
493	0	}