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are met:
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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***********************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef FIXED_POINT
#include "main_FIX.h"
#define silk_encoder_state_Fxx      silk_encoder_state_FIX
#else
#include "main_FLP.h"
#define silk_encoder_state_Fxx      silk_encoder_state_FLP
#endif
#include "stack_alloc.h"
#include "tuning_parameters.h"
#include "pitch_est_defines.h"

static opus_int silk_setup_resamplers(
    silk_encoder_state_Fxx          *psEnc,             /* I/O                      */
    opus_int                        fs_kHz              /* I                        */
);

static opus_int silk_setup_fs(
    silk_encoder_state_Fxx          *psEnc,             /* I/O                      */
    opus_int                        fs_kHz,             /* I                        */
    opus_int                        PacketSize_ms       /* I                        */
);

static opus_int silk_setup_complexity(
    silk_encoder_state              *psEncC,            /* I/O                      */
    opus_int                        Complexity          /* I                        */
);

static OPUS_INLINE opus_int silk_setup_LBRR(
    silk_encoder_state              *psEncC,            /* I/O                      */
    const opus_int32                TargetRate_bps      /* I                        */
);


/* Control encoder */
opus_int silk_control_encoder(
    silk_encoder_state_Fxx          *psEnc,                                 /* I/O  Pointer to Silk encoder state                                               */
    silk_EncControlStruct           *encControl,                            /* I    Control structure                                                           */
    const opus_int32                TargetRate_bps,                         /* I    Target max bitrate (bps)                                                    */
    const opus_int                  allow_bw_switch,                        /* I    Flag to allow switching audio bandwidth                                     */
    const opus_int                  channelNb,                              /* I    Channel number                                                              */
    const opus_int                  force_fs_kHz
)
{
    opus_int   fs_kHz, ret = 0;

    psEnc->sCmn.useDTX                 = encControl->useDTX;
    psEnc->sCmn.useCBR                 = encControl->useCBR;
    psEnc->sCmn.API_fs_Hz              = encControl->API_sampleRate;
    psEnc->sCmn.maxInternal_fs_Hz      = encControl->maxInternalSampleRate;
    psEnc->sCmn.minInternal_fs_Hz      = encControl->minInternalSampleRate;
    psEnc->sCmn.desiredInternal_fs_Hz  = encControl->desiredInternalSampleRate;
    psEnc->sCmn.useInBandFEC           = encControl->useInBandFEC;
    psEnc->sCmn.nChannelsAPI           = encControl->nChannelsAPI;
    psEnc->sCmn.nChannelsInternal      = encControl->nChannelsInternal;
    psEnc->sCmn.allow_bandwidth_switch = allow_bw_switch;
    psEnc->sCmn.channelNb              = channelNb;

    if( psEnc->sCmn.controlled_since_last_payload != 0 && psEnc->sCmn.prefillFlag == 0 ) {
        if( psEnc->sCmn.API_fs_Hz != psEnc->sCmn.prev_API_fs_Hz && psEnc->sCmn.fs_kHz > 0 ) {
            /* Change in API sampling rate in the middle of encoding a packet */
            ret += silk_setup_resamplers( psEnc, psEnc->sCmn.fs_kHz );
        }
        return ret;
    }

    /* Beyond this point we know that there are no previously coded frames in the payload buffer */

    /********************************************/
    /* Determine internal sampling rate         */
    /********************************************/
    fs_kHz = silk_control_audio_bandwidth( &psEnc->sCmn, encControl );
    if( force_fs_kHz ) {
       fs_kHz = force_fs_kHz;
    }
    /********************************************/
    /* Prepare resampler and buffered data      */
    /********************************************/
    ret += silk_setup_resamplers( psEnc, fs_kHz );

    /********************************************/
    /* Set internal sampling frequency          */
    /********************************************/
    ret += silk_setup_fs( psEnc, fs_kHz, encControl->payloadSize_ms );

    /********************************************/
    /* Set encoding complexity                  */
    /********************************************/
    ret += silk_setup_complexity( &psEnc->sCmn, encControl->complexity  );

    /********************************************/
    /* Set packet loss rate measured by farend  */
    /********************************************/
    psEnc->sCmn.PacketLoss_perc = encControl->packetLossPercentage;

    /********************************************/
    /* Set LBRR usage                           */
    /********************************************/
    ret += silk_setup_LBRR( &psEnc->sCmn, TargetRate_bps );

    psEnc->sCmn.controlled_since_last_payload = 1;

    return ret;
}

static opus_int silk_setup_resamplers(
    silk_encoder_state_Fxx          *psEnc,             /* I/O                      */
    opus_int                         fs_kHz              /* I                        */
)
{
    opus_int   ret = SILK_NO_ERROR;
    SAVE_STACK;

    if( psEnc->sCmn.fs_kHz != fs_kHz || psEnc->sCmn.prev_API_fs_Hz != psEnc->sCmn.API_fs_Hz )
    {
        if( psEnc->sCmn.fs_kHz == 0 ) {
            /* Initialize the resampler for enc_API.c preparing resampling from API_fs_Hz to fs_kHz */
            ret += silk_resampler_init( &psEnc->sCmn.resampler_state, psEnc->sCmn.API_fs_Hz, fs_kHz * 1000, 1 );
        } else {
            VARDECL( opus_int16, x_buf_API_fs_Hz );
            VARDECL( silk_resampler_state_struct, temp_resampler_state );
#ifdef FIXED_POINT
            opus_int16 *x_bufFIX = psEnc->x_buf;
#else
            VARDECL( opus_int16, x_bufFIX );
            opus_int32 new_buf_samples;
#endif
            opus_int32 api_buf_samples;
            opus_int32 old_buf_samples;
            opus_int32 buf_length_ms;

            buf_length_ms = silk_LSHIFT( psEnc->sCmn.nb_subfr * 5, 1 ) + LA_SHAPE_MS;
            old_buf_samples = buf_length_ms * psEnc->sCmn.fs_kHz;

#ifndef FIXED_POINT
            new_buf_samples = buf_length_ms * fs_kHz;
            ALLOC( x_bufFIX, silk_max( old_buf_samples, new_buf_samples ),
                   opus_int16 );
            silk_float2short_array( x_bufFIX, psEnc->x_buf, old_buf_samples );
#endif

            /* Initialize resampler for temporary resampling of x_buf data to API_fs_Hz */
            ALLOC( temp_resampler_state, 1, silk_resampler_state_struct );
            ret += silk_resampler_init( temp_resampler_state, silk_SMULBB( psEnc->sCmn.fs_kHz, 1000 ), psEnc->sCmn.API_fs_Hz, 0 );

            /* Calculate number of samples to temporarily upsample */
            api_buf_samples = buf_length_ms * silk_DIV32_16( psEnc->sCmn.API_fs_Hz, 1000 );

            /* Temporary resampling of x_buf data to API_fs_Hz */
            ALLOC( x_buf_API_fs_Hz, api_buf_samples, opus_int16 );
            ret += silk_resampler( temp_resampler_state, x_buf_API_fs_Hz, x_bufFIX, old_buf_samples );

            /* Initialize the resampler for enc_API.c preparing resampling from API_fs_Hz to fs_kHz */
            ret += silk_resampler_init( &psEnc->sCmn.resampler_state, psEnc->sCmn.API_fs_Hz, silk_SMULBB( fs_kHz, 1000 ), 1 );

            /* Correct resampler state by resampling buffered data from API_fs_Hz to fs_kHz */
            ret += silk_resampler( &psEnc->sCmn.resampler_state, x_bufFIX, x_buf_API_fs_Hz, api_buf_samples );

#ifndef FIXED_POINT
            silk_short2float_array( psEnc->x_buf, x_bufFIX, new_buf_samples);
#endif
        }
    }

    psEnc->sCmn.prev_API_fs_Hz = psEnc->sCmn.API_fs_Hz;

    RESTORE_STACK;
    return ret;
}

static opus_int silk_setup_fs(
    silk_encoder_state_Fxx          *psEnc,             /* I/O                      */
    opus_int                        fs_kHz,             /* I                        */
    opus_int                        PacketSize_ms       /* I                        */
)
{
    opus_int ret = SILK_NO_ERROR;

    /* Set packet size */
    if( PacketSize_ms != psEnc->sCmn.PacketSize_ms ) {
        if( ( PacketSize_ms !=  10 ) &&
            ( PacketSize_ms !=  20 ) &&
            ( PacketSize_ms !=  40 ) &&
            ( PacketSize_ms !=  60 ) ) {
            ret = SILK_ENC_PACKET_SIZE_NOT_SUPPORTED;
        }
        if( PacketSize_ms <= 10 ) {
            psEnc->sCmn.nFramesPerPacket = 1;
            psEnc->sCmn.nb_subfr = PacketSize_ms == 10 ? 2 : 1;
            psEnc->sCmn.frame_length = silk_SMULBB( PacketSize_ms, fs_kHz );
            psEnc->sCmn.pitch_LPC_win_length = silk_SMULBB( FIND_PITCH_LPC_WIN_MS_2_SF, fs_kHz );
            if( psEnc->sCmn.fs_kHz == 8 ) {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_NB_iCDF;
            } else {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_iCDF;
            }
        } else {
            psEnc->sCmn.nFramesPerPacket = silk_DIV32_16( PacketSize_ms, MAX_FRAME_LENGTH_MS );
            psEnc->sCmn.nb_subfr = MAX_NB_SUBFR;
            psEnc->sCmn.frame_length = silk_SMULBB( 20, fs_kHz );
            psEnc->sCmn.pitch_LPC_win_length = silk_SMULBB( FIND_PITCH_LPC_WIN_MS, fs_kHz );
            if( psEnc->sCmn.fs_kHz == 8 ) {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_NB_iCDF;
            } else {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_iCDF;
            }
        }
        psEnc->sCmn.PacketSize_ms  = PacketSize_ms;
        psEnc->sCmn.TargetRate_bps = 0;         /* trigger new SNR computation */
    }

    /* Set internal sampling frequency */
    silk_assert( fs_kHz == 8 || fs_kHz == 12 || fs_kHz == 16 );
    silk_assert( psEnc->sCmn.nb_subfr == 2 || psEnc->sCmn.nb_subfr == 4 );
    if( psEnc->sCmn.fs_kHz != fs_kHz ) {
        /* reset part of the state */
        silk_memset( &psEnc->sShape,               0, sizeof( psEnc->sShape ) );
        silk_memset( &psEnc->sPrefilt,             0, sizeof( psEnc->sPrefilt ) );
        silk_memset( &psEnc->sCmn.sNSQ,            0, sizeof( psEnc->sCmn.sNSQ ) );
        silk_memset( psEnc->sCmn.prev_NLSFq_Q15,   0, sizeof( psEnc->sCmn.prev_NLSFq_Q15 ) );
        silk_memset( &psEnc->sCmn.sLP.In_LP_State, 0, sizeof( psEnc->sCmn.sLP.In_LP_State ) );
        psEnc->sCmn.inputBufIx                  = 0;
        psEnc->sCmn.nFramesEncoded              = 0;
        psEnc->sCmn.TargetRate_bps              = 0;     /* trigger new SNR computation */

        /* Initialize non-zero parameters */
        psEnc->sCmn.prevLag                     = 100;
        psEnc->sCmn.first_frame_after_reset     = 1;
        psEnc->sPrefilt.lagPrev                 = 100;
        psEnc->sShape.LastGainIndex             = 10;
        psEnc->sCmn.sNSQ.lagPrev                = 100;
        psEnc->sCmn.sNSQ.prev_gain_Q16          = 65536;
        psEnc->sCmn.prevSignalType              = TYPE_NO_VOICE_ACTIVITY;

        psEnc->sCmn.fs_kHz = fs_kHz;
        if( psEnc->sCmn.fs_kHz == 8 ) {
            if( psEnc->sCmn.nb_subfr == MAX_NB_SUBFR ) {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_NB_iCDF;
            } else {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_NB_iCDF;
            }
        } else {
            if( psEnc->sCmn.nb_subfr == MAX_NB_SUBFR ) {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_iCDF;
            } else {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_iCDF;
            }
        }
        if( psEnc->sCmn.fs_kHz == 8 || psEnc->sCmn.fs_kHz == 12 ) {
            psEnc->sCmn.predictLPCOrder = MIN_LPC_ORDER;
            psEnc->sCmn.psNLSF_CB  = &silk_NLSF_CB_NB_MB;
        } else {
            psEnc->sCmn.predictLPCOrder = MAX_LPC_ORDER;
            psEnc->sCmn.psNLSF_CB  = &silk_NLSF_CB_WB;
        }
        psEnc->sCmn.subfr_length   = SUB_FRAME_LENGTH_MS * fs_kHz;
        psEnc->sCmn.frame_length   = silk_SMULBB( psEnc->sCmn.subfr_length, psEnc->sCmn.nb_subfr );
        psEnc->sCmn.ltp_mem_length = silk_SMULBB( LTP_MEM_LENGTH_MS, fs_kHz );
        psEnc->sCmn.la_pitch       = silk_SMULBB( LA_PITCH_MS, fs_kHz );
        psEnc->sCmn.max_pitch_lag  = silk_SMULBB( 18, fs_kHz );
        if( psEnc->sCmn.nb_subfr == MAX_NB_SUBFR ) {
            psEnc->sCmn.pitch_LPC_win_length = silk_SMULBB( FIND_PITCH_LPC_WIN_MS, fs_kHz );
        } else {
            psEnc->sCmn.pitch_LPC_win_length = silk_SMULBB( FIND_PITCH_LPC_WIN_MS_2_SF, fs_kHz );
        }
        if( psEnc->sCmn.fs_kHz == 16 ) {
            psEnc->sCmn.mu_LTP_Q9 = SILK_FIX_CONST( MU_LTP_QUANT_WB, 9 );
            psEnc->sCmn.pitch_lag_low_bits_iCDF = silk_uniform8_iCDF;
        } else if( psEnc->sCmn.fs_kHz == 12 ) {
            psEnc->sCmn.mu_LTP_Q9 = SILK_FIX_CONST( MU_LTP_QUANT_MB, 9 );
            psEnc->sCmn.pitch_lag_low_bits_iCDF = silk_uniform6_iCDF;
        } else {
            psEnc->sCmn.mu_LTP_Q9 = SILK_FIX_CONST( MU_LTP_QUANT_NB, 9 );
            psEnc->sCmn.pitch_lag_low_bits_iCDF = silk_uniform4_iCDF;
        }
    }

    /* Check that settings are valid */
    silk_assert( ( psEnc->sCmn.subfr_length * psEnc->sCmn.nb_subfr ) == psEnc->sCmn.frame_length );

    return ret;
}

static opus_int silk_setup_complexity(
    silk_encoder_state              *psEncC,            /* I/O                      */
    opus_int                        Complexity          /* I                        */
)
{
    opus_int ret = 0;

    /* Set encoding complexity */
    silk_assert( Complexity >= 0 && Complexity <= 10 );
    if( Complexity < 2 ) {
        psEncC->pitchEstimationComplexity       = SILK_PE_MIN_COMPLEX;
        psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.8, 16 );
        psEncC->pitchEstimationLPCOrder         = 6;
        psEncC->shapingLPCOrder                 = 8;
        psEncC->la_shape                        = 3 * psEncC->fs_kHz;
        psEncC->nStatesDelayedDecision          = 1;
        psEncC->useInterpolatedNLSFs            = 0;
        psEncC->LTPQuantLowComplexity           = 1;
        psEncC->NLSF_MSVQ_Survivors             = 2;
        psEncC->warping_Q16                     = 0;
    } else if( Complexity < 4 ) {
        psEncC->pitchEstimationComplexity       = SILK_PE_MID_COMPLEX;
        psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.76, 16 );
        psEncC->pitchEstimationLPCOrder         = 8;
        psEncC->shapingLPCOrder                 = 10;
        psEncC->la_shape                        = 5 * psEncC->fs_kHz;
        psEncC->nStatesDelayedDecision          = 1;
        psEncC->useInterpolatedNLSFs            = 0;
        psEncC->LTPQuantLowComplexity           = 0;
        psEncC->NLSF_MSVQ_Survivors             = 4;
        psEncC->warping_Q16                     = 0;
    } else if( Complexity < 6 ) {
        psEncC->pitchEstimationComplexity       = SILK_PE_MID_COMPLEX;
        psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.74, 16 );
        psEncC->pitchEstimationLPCOrder         = 10;
        psEncC->shapingLPCOrder                 = 12;
        psEncC->la_shape                        = 5 * psEncC->fs_kHz;
        psEncC->nStatesDelayedDecision          = 2;
        psEncC->useInterpolatedNLSFs            = 1;
        psEncC->LTPQuantLowComplexity           = 0;
        psEncC->NLSF_MSVQ_Survivors             = 8;
        psEncC->warping_Q16                     = psEncC->fs_kHz * SILK_FIX_CONST( WARPING_MULTIPLIER, 16 );
    } else if( Complexity < 8 ) {
        psEncC->pitchEstimationComplexity       = SILK_PE_MID_COMPLEX;
        psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.72, 16 );
        psEncC->pitchEstimationLPCOrder         = 12;
        psEncC->shapingLPCOrder                 = 14;
        psEncC->la_shape                        = 5 * psEncC->fs_kHz;
        psEncC->nStatesDelayedDecision          = 3;
        psEncC->useInterpolatedNLSFs            = 1;
        psEncC->LTPQuantLowComplexity           = 0;
        psEncC->NLSF_MSVQ_Survivors             = 16;
        psEncC->warping_Q16                     = psEncC->fs_kHz * SILK_FIX_CONST( WARPING_MULTIPLIER, 16 );
    } else {
        psEncC->pitchEstimationComplexity       = SILK_PE_MAX_COMPLEX;
        psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.7, 16 );
        psEncC->pitchEstimationLPCOrder         = 16;
        psEncC->shapingLPCOrder                 = 16;
        psEncC->la_shape                        = 5 * psEncC->fs_kHz;
        psEncC->nStatesDelayedDecision          = MAX_DEL_DEC_STATES;
        psEncC->useInterpolatedNLSFs            = 1;
        psEncC->LTPQuantLowComplexity           = 0;
        psEncC->NLSF_MSVQ_Survivors             = 32;
        psEncC->warping_Q16                     = psEncC->fs_kHz * SILK_FIX_CONST( WARPING_MULTIPLIER, 16 );
    }

    /* Do not allow higher pitch estimation LPC order than predict LPC order */
    psEncC->pitchEstimationLPCOrder = silk_min_int( psEncC->pitchEstimationLPCOrder, psEncC->predictLPCOrder );
    psEncC->shapeWinLength          = SUB_FRAME_LENGTH_MS * psEncC->fs_kHz + 2 * psEncC->la_shape;
    psEncC->Complexity              = Complexity;

    silk_assert( psEncC->pitchEstimationLPCOrder <= MAX_FIND_PITCH_LPC_ORDER );
    silk_assert( psEncC->shapingLPCOrder         <= MAX_SHAPE_LPC_ORDER      );
    silk_assert( psEncC->nStatesDelayedDecision  <= MAX_DEL_DEC_STATES       );
    silk_assert( psEncC->warping_Q16             <= 32767                    );
    silk_assert( psEncC->la_shape                <= LA_SHAPE_MAX             );
    silk_assert( psEncC->shapeWinLength          <= SHAPE_LPC_WIN_MAX        );
    silk_assert( psEncC->NLSF_MSVQ_Survivors     <= NLSF_VQ_MAX_SURVIVORS    );

    return ret;
}

static OPUS_INLINE opus_int silk_setup_LBRR(
    silk_encoder_state          *psEncC,            /* I/O                      */
    const opus_int32            TargetRate_bps      /* I                        */
)
{
    opus_int   LBRR_in_previous_packet, ret = SILK_NO_ERROR;
    opus_int32 LBRR_rate_thres_bps;

    LBRR_in_previous_packet = psEncC->LBRR_enabled;
    psEncC->LBRR_enabled = 0;
    if( psEncC->useInBandFEC && psEncC->PacketLoss_perc > 0 ) {
        if( psEncC->fs_kHz == 8 ) {
            LBRR_rate_thres_bps = LBRR_NB_MIN_RATE_BPS;
        } else if( psEncC->fs_kHz == 12 ) {
            LBRR_rate_thres_bps = LBRR_MB_MIN_RATE_BPS;
        } else {
            LBRR_rate_thres_bps = LBRR_WB_MIN_RATE_BPS;
        }
        LBRR_rate_thres_bps = silk_SMULWB( silk_MUL( LBRR_rate_thres_bps, 125 - silk_min( psEncC->PacketLoss_perc, 25 ) ), SILK_FIX_CONST( 0.01, 16 ) );

        if( TargetRate_bps > LBRR_rate_thres_bps ) {
            /* Set gain increase for coding LBRR excitation */
            if( LBRR_in_previous_packet == 0 ) {
                /* Previous packet did not have LBRR, and was therefore coded at a higher bitrate */
                psEncC->LBRR_GainIncreases = 7;
            } else {
                psEncC->LBRR_GainIncreases = silk_max_int( 7 - silk_SMULWB( (opus_int32)psEncC->PacketLoss_perc, SILK_FIX_CONST( 0.4, 16 ) ), 2 );
            }
            psEncC->LBRR_enabled = 1;
        }
    }

    return ret;
}