freeswitch/libs/silk/src/SKP_Silk_control_codec_FIX.c

/***********************************************************************
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#include "SKP_Silk_main_FIX.h"
#include "SKP_Silk_setup_complexity.h"

SKP_INLINE SKP_int SKP_Silk_setup_resamplers_FIX(
    SKP_Silk_encoder_state_FIX      *psEnc,             /* I/O  Pointer to Silk encoder state FIX       */
    SKP_int                         fs_kHz              /* I    Internal sampling rate (kHz)            */
);

SKP_INLINE SKP_int SKP_Silk_setup_packetsize_FIX(
    SKP_Silk_encoder_state_FIX      *psEnc,             /* I/O  Pointer to Silk encoder state FIX       */
    SKP_int                         PacketSize_ms       /* I    Packet length (ms)                      */
);

SKP_INLINE SKP_int SKP_Silk_setup_fs_FIX(
    SKP_Silk_encoder_state_FIX      *psEnc,             /* I/O  Pointer to Silk encoder state FIX       */
    SKP_int                         fs_kHz              /* I    Internal sampling rate (kHz)            */
);

SKP_INLINE SKP_int SKP_Silk_setup_rate_FIX(
    SKP_Silk_encoder_state_FIX      *psEnc,             /* I/O  Pointer to Silk encoder state FIX       */
    SKP_int                         TargetRate_bps      /* I    Target max bitrate (if SNR_dB == 0)     */
);

SKP_INLINE SKP_int SKP_Silk_setup_LBRR_FIX(
    SKP_Silk_encoder_state_FIX      *psEnc              /* I/O  Pointer to Silk encoder state FIX       */
);

/* Control encoder */
SKP_int SKP_Silk_control_encoder_FIX( 
    SKP_Silk_encoder_state_FIX  *psEnc,                 /* I/O  Pointer to Silk encoder state           */
    const SKP_int               PacketSize_ms,          /* I    Packet length (ms)                      */
    const SKP_int32             TargetRate_bps,         /* I    Target max bitrate (bps)                */
    const SKP_int               PacketLoss_perc,        /* I    Packet loss rate (in percent)           */
    const SKP_int               DTX_enabled,            /* I    Enable / disable DTX                    */
    const SKP_int               Complexity              /* I    Complexity (0->low; 1->medium; 2->high) */
)
{
    SKP_int   fs_kHz, ret = 0;

    if( psEnc->sCmn.controlled_since_last_payload != 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 += SKP_Silk_setup_resamplers_FIX( 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 = SKP_Silk_control_audio_bandwidth( &psEnc->sCmn, TargetRate_bps );

    /********************************************/
    /* Prepare resampler and buffered data      */
    /********************************************/
    ret += SKP_Silk_setup_resamplers_FIX( psEnc, fs_kHz );

    /********************************************/
    /* Set packet size                          */
    /********************************************/
    ret += SKP_Silk_setup_packetsize_FIX( psEnc, PacketSize_ms );

    /********************************************/
    /* Set internal sampling frequency          */
    /********************************************/
    ret += SKP_Silk_setup_fs_FIX( psEnc, fs_kHz );

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

    /********************************************/
    /* Set bitrate/coding quality               */
    /********************************************/
    ret += SKP_Silk_setup_rate_FIX( psEnc, TargetRate_bps );

    /********************************************/
    /* Set packet loss rate measured by farend  */
    /********************************************/
    if( ( PacketLoss_perc < 0 ) || ( PacketLoss_perc > 100 ) ) {
        ret = SKP_SILK_ENC_INVALID_LOSS_RATE;
    }
    psEnc->sCmn.PacketLoss_perc = PacketLoss_perc;

    /********************************************/
    /* Set LBRR usage                           */
    /********************************************/
    ret += SKP_Silk_setup_LBRR_FIX( psEnc );

    /********************************************/
    /* Set DTX mode                             */
    /********************************************/
    if( DTX_enabled < 0 || DTX_enabled > 1 ) {
        ret = SKP_SILK_ENC_INVALID_DTX_SETTING;
    }
    psEnc->sCmn.useDTX = DTX_enabled;
    psEnc->sCmn.controlled_since_last_payload = 1;

    return ret;
}

/* Control low bitrate redundancy usage */
void SKP_Silk_LBRR_ctrl_FIX(
    SKP_Silk_encoder_state_FIX      *psEnc,     /* I    Encoder state FIX                           */
    SKP_Silk_encoder_control        *psEncCtrlC /* I/O  Encoder control                             */
)
{
    SKP_int LBRR_usage;

    if( psEnc->sCmn.LBRR_enabled ) {
        /* Control LBRR */

        /* Usage Control based on sensitivity and packet loss caracteristics */
        /* For now only enable adding to next for active frames. Make more complex later */
        LBRR_usage = SKP_SILK_NO_LBRR;
        if( psEnc->speech_activity_Q8 > SKP_FIX_CONST( LBRR_SPEECH_ACTIVITY_THRES, 8 ) && psEnc->sCmn.PacketLoss_perc > LBRR_LOSS_THRES ) { // nb! maybe multiply loss prob and speech activity 
            LBRR_usage = SKP_SILK_ADD_LBRR_TO_PLUS1;
        }
        psEncCtrlC->LBRR_usage = LBRR_usage;
    } else {
        psEncCtrlC->LBRR_usage = SKP_SILK_NO_LBRR;
    }
}

SKP_INLINE SKP_int SKP_Silk_setup_resamplers_FIX(
    SKP_Silk_encoder_state_FIX      *psEnc,             /* I/O  Pointer to Silk encoder state FIX       */
    SKP_int                         fs_kHz              /* I    Internal sampling rate (kHz)            */
)
{
    SKP_int ret = SKP_SILK_NO_ERROR;
    
    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 += SKP_Silk_resampler_init( &psEnc->sCmn.resampler_state, psEnc->sCmn.API_fs_Hz, fs_kHz * 1000 );
        } else {
            /* Allocate space for worst case temporary upsampling, 8 to 48 kHz, so a factor 6 */
            SKP_int16 x_buf_API_fs_Hz[ ( 2 * MAX_FRAME_LENGTH + LA_SHAPE_MAX ) * ( MAX_API_FS_KHZ / 8 ) ];

            SKP_int32 nSamples_temp = SKP_LSHIFT( psEnc->sCmn.frame_length, 1 ) + LA_SHAPE_MS * psEnc->sCmn.fs_kHz;

            if( SKP_SMULBB( fs_kHz, 1000 ) < psEnc->sCmn.API_fs_Hz && psEnc->sCmn.fs_kHz != 0 ) {
                /* Resample buffered data in x_buf to API_fs_Hz */

                SKP_Silk_resampler_state_struct  temp_resampler_state;

                /* Initialize resampler for temporary resampling of x_buf data to API_fs_Hz */
                ret += SKP_Silk_resampler_init( &temp_resampler_state, SKP_SMULBB( psEnc->sCmn.fs_kHz, 1000 ), psEnc->sCmn.API_fs_Hz );

                /* Temporary resampling of x_buf data to API_fs_Hz */
                ret += SKP_Silk_resampler( &temp_resampler_state, x_buf_API_fs_Hz, psEnc->x_buf, nSamples_temp );

                /* Calculate number of samples that has been temporarily upsampled */
                nSamples_temp = SKP_DIV32_16( nSamples_temp * psEnc->sCmn.API_fs_Hz, SKP_SMULBB( psEnc->sCmn.fs_kHz, 1000 ) );

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

            } else {
                /* Copy data */
                SKP_memcpy( x_buf_API_fs_Hz, psEnc->x_buf, nSamples_temp * sizeof( SKP_int16 ) );
            }

            if( 1000 * fs_kHz != psEnc->sCmn.API_fs_Hz ) {
                /* Correct resampler state (unless resampling by a factor 1) by resampling buffered data from API_fs_Hz to fs_kHz */
                ret += SKP_Silk_resampler( &psEnc->sCmn.resampler_state, psEnc->x_buf, x_buf_API_fs_Hz, nSamples_temp );
            }
        }
    }

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

    return(ret);
}

SKP_INLINE SKP_int SKP_Silk_setup_packetsize_FIX(
    SKP_Silk_encoder_state_FIX      *psEnc,             /* I/O  Pointer to Silk encoder state FIX       */
    SKP_int                         PacketSize_ms       /* I    Packet length (ms)                      */
)
{
    SKP_int ret = SKP_SILK_NO_ERROR;

    /* Set packet size */
    if( ( PacketSize_ms !=  20 ) && 
        ( PacketSize_ms !=  40 ) && 
        ( PacketSize_ms !=  60 ) && 
        ( PacketSize_ms !=  80 ) && 
        ( PacketSize_ms != 100 ) ) {
        ret = SKP_SILK_ENC_PACKET_SIZE_NOT_SUPPORTED;
    } else {
        if( PacketSize_ms != psEnc->sCmn.PacketSize_ms ) {
            psEnc->sCmn.PacketSize_ms = PacketSize_ms;

            /* Packet length changes. Reset LBRR buffer */
            SKP_Silk_LBRR_reset( &psEnc->sCmn );
        }
    }
    return(ret);
}

SKP_INLINE SKP_int SKP_Silk_setup_fs_FIX(
    SKP_Silk_encoder_state_FIX      *psEnc,             /* I/O  Pointer to Silk encoder state FIX       */
    SKP_int                         fs_kHz              /* I    Internal sampling rate (kHz)            */
)
{
    SKP_int ret = SKP_SILK_NO_ERROR;

    /* Set internal sampling frequency */
    if( psEnc->sCmn.fs_kHz != fs_kHz ) {
        /* reset part of the state */
        SKP_memset( &psEnc->sShape,          0,                            sizeof( SKP_Silk_shape_state_FIX ) );
        SKP_memset( &psEnc->sPrefilt,        0,                            sizeof( SKP_Silk_prefilter_state_FIX ) );
        SKP_memset( &psEnc->sNSQ,            0,                            sizeof( SKP_Silk_nsq_state ) );
        SKP_memset( &psEnc->sPred,           0,                            sizeof( SKP_Silk_predict_state_FIX ) );
        SKP_memset( psEnc->sNSQ.xq,          0, ( 2 * MAX_FRAME_LENGTH ) * sizeof( SKP_int16 ) );
        SKP_memset( psEnc->sNSQ_LBRR.xq,     0, ( 2 * MAX_FRAME_LENGTH ) * sizeof( SKP_int16 ) );
        SKP_memset( psEnc->sCmn.LBRR_buffer, 0,           MAX_LBRR_DELAY * sizeof( SKP_SILK_LBRR_struct ) );
#if SWITCH_TRANSITION_FILTERING
        SKP_memset( psEnc->sCmn.sLP.In_LP_State, 0, 2 * sizeof( SKP_int32 ) );
        if( psEnc->sCmn.sLP.mode == 1 ) {
            /* Begin transition phase */
            psEnc->sCmn.sLP.transition_frame_no = 1;
        } else {
            /* End transition phase */
            psEnc->sCmn.sLP.transition_frame_no = 0;
        }
#endif
        psEnc->sCmn.inputBufIx          = 0;
        psEnc->sCmn.nFramesInPayloadBuf = 0;
        psEnc->sCmn.nBytesInPayloadBuf  = 0;
        psEnc->sCmn.oldest_LBRR_idx     = 0;
        psEnc->sCmn.TargetRate_bps      = 0; /* Ensures that psEnc->SNR_dB is recomputed */

        SKP_memset( psEnc->sPred.prev_NLSFq_Q15, 0, MAX_LPC_ORDER * sizeof( SKP_int ) );

        /* Initialize non-zero parameters */
        psEnc->sCmn.prevLag                 = 100;
        psEnc->sCmn.prev_sigtype            = SIG_TYPE_UNVOICED;
        psEnc->sCmn.first_frame_after_reset = 1;
        psEnc->sPrefilt.lagPrev             = 100;
        psEnc->sShape.LastGainIndex         = 1;
        psEnc->sNSQ.lagPrev                 = 100;
        psEnc->sNSQ.prev_inv_gain_Q16       = 65536;
        psEnc->sNSQ_LBRR.prev_inv_gain_Q16  = 65536;

        psEnc->sCmn.fs_kHz = fs_kHz;
        if( psEnc->sCmn.fs_kHz == 8 ) {
            psEnc->sCmn.predictLPCOrder = MIN_LPC_ORDER;
            psEnc->sCmn.psNLSF_CB[ 0 ]  = &SKP_Silk_NLSF_CB0_10;
            psEnc->sCmn.psNLSF_CB[ 1 ]  = &SKP_Silk_NLSF_CB1_10;
        } else {
            psEnc->sCmn.predictLPCOrder = MAX_LPC_ORDER;
            psEnc->sCmn.psNLSF_CB[ 0 ]  = &SKP_Silk_NLSF_CB0_16;
            psEnc->sCmn.psNLSF_CB[ 1 ]  = &SKP_Silk_NLSF_CB1_16;
        }
        psEnc->sCmn.frame_length   = SKP_SMULBB( FRAME_LENGTH_MS, fs_kHz );
        psEnc->sCmn.subfr_length   = SKP_DIV32_16( psEnc->sCmn.frame_length, NB_SUBFR );
        psEnc->sCmn.la_pitch       = SKP_SMULBB( LA_PITCH_MS, fs_kHz );
        psEnc->sPred.min_pitch_lag = SKP_SMULBB(  3, fs_kHz );
        psEnc->sPred.max_pitch_lag = SKP_SMULBB( 18, fs_kHz );
        psEnc->sPred.pitch_LPC_win_length = SKP_SMULBB( FIND_PITCH_LPC_WIN_MS, fs_kHz );
        if( psEnc->sCmn.fs_kHz == 24 ) {
            psEnc->mu_LTP_Q8 = SKP_FIX_CONST( MU_LTP_QUANT_SWB, 8 );
            psEnc->sCmn.bitrate_threshold_up   = SKP_int32_MAX;
            psEnc->sCmn.bitrate_threshold_down = SWB2WB_BITRATE_BPS; 
        } else if( psEnc->sCmn.fs_kHz == 16 ) {
            psEnc->mu_LTP_Q8 = SKP_FIX_CONST( MU_LTP_QUANT_WB, 8 );
            psEnc->sCmn.bitrate_threshold_up   = WB2SWB_BITRATE_BPS;
            psEnc->sCmn.bitrate_threshold_down = WB2MB_BITRATE_BPS; 
        } else if( psEnc->sCmn.fs_kHz == 12 ) {
            psEnc->mu_LTP_Q8 = SKP_FIX_CONST( MU_LTP_QUANT_MB, 8 );
            psEnc->sCmn.bitrate_threshold_up   = MB2WB_BITRATE_BPS;
            psEnc->sCmn.bitrate_threshold_down = MB2NB_BITRATE_BPS;
        } else {
            psEnc->mu_LTP_Q8 = SKP_FIX_CONST( MU_LTP_QUANT_NB, 8 );
            psEnc->sCmn.bitrate_threshold_up   = NB2MB_BITRATE_BPS;
            psEnc->sCmn.bitrate_threshold_down = 0;
        }
        psEnc->sCmn.fs_kHz_changed = 1;

        /* Check that settings are valid */
        SKP_assert( ( psEnc->sCmn.subfr_length * NB_SUBFR ) == psEnc->sCmn.frame_length );
    }
    return( ret );
}

SKP_INLINE SKP_int SKP_Silk_setup_rate_FIX(
    SKP_Silk_encoder_state_FIX      *psEnc,             /* I/O  Pointer to Silk encoder state FIX       */
    SKP_int                         TargetRate_bps      /* I    Target max bitrate (if SNR_dB == 0)     */
)
{
    SKP_int k, ret = SKP_SILK_NO_ERROR;
    SKP_int32 frac_Q6;
    const SKP_int32 *rateTable;

    /* Set bitrate/coding quality */
    if( TargetRate_bps != psEnc->sCmn.TargetRate_bps ) {
        psEnc->sCmn.TargetRate_bps = TargetRate_bps;

        /* If new TargetRate_bps, translate to SNR_dB value */
        if( psEnc->sCmn.fs_kHz == 8 ) {
            rateTable = TargetRate_table_NB;
        } else if( psEnc->sCmn.fs_kHz == 12 ) {
            rateTable = TargetRate_table_MB;
        } else if( psEnc->sCmn.fs_kHz == 16 ) {
            rateTable = TargetRate_table_WB;
        } else {
            rateTable = TargetRate_table_SWB;
        }
        for( k = 1; k < TARGET_RATE_TAB_SZ; k++ ) {
            /* Find bitrate interval in table and interpolate */
            if( TargetRate_bps < rateTable[ k ] ) {
                frac_Q6 = SKP_DIV32( SKP_LSHIFT( TargetRate_bps - rateTable[ k - 1 ], 6 ), 
                                                 rateTable[ k ] - rateTable[ k - 1 ] );
                psEnc->SNR_dB_Q7 = SKP_LSHIFT( SNR_table_Q1[ k - 1 ], 6 ) + SKP_MUL( frac_Q6, SNR_table_Q1[ k ] - SNR_table_Q1[ k - 1 ] );
                break;
            }
        }
    }
    return( ret );
}

SKP_INLINE SKP_int SKP_Silk_setup_LBRR_FIX(
    SKP_Silk_encoder_state_FIX      *psEnc              /* I/O  Pointer to Silk encoder state FIX       */
)
{
    SKP_int   ret = SKP_SILK_NO_ERROR;
#if USE_LBRR
    SKP_int32 LBRRRate_thres_bps;

    if( psEnc->sCmn.useInBandFEC < 0 || psEnc->sCmn.useInBandFEC > 1 ) {
        ret = SKP_SILK_ENC_INVALID_INBAND_FEC_SETTING;
    }
    
    psEnc->sCmn.LBRR_enabled = psEnc->sCmn.useInBandFEC;
    if( psEnc->sCmn.fs_kHz == 8 ) {
        LBRRRate_thres_bps = INBAND_FEC_MIN_RATE_BPS - 9000;
    } else if( psEnc->sCmn.fs_kHz == 12 ) {
        LBRRRate_thres_bps = INBAND_FEC_MIN_RATE_BPS - 6000;;
    } else if( psEnc->sCmn.fs_kHz == 16 ) {
        LBRRRate_thres_bps = INBAND_FEC_MIN_RATE_BPS - 3000;
    } else {
        LBRRRate_thres_bps = INBAND_FEC_MIN_RATE_BPS;
    }

    if( psEnc->sCmn.TargetRate_bps >= LBRRRate_thres_bps ) {
        /* Set gain increase / rate reduction for LBRR usage */
        /* Coarsely tuned with PESQ for now. */
        /* Linear regression coefs G = 8 - 0.5 * loss */
        /* Meaning that at 16% loss main rate and redundant rate is the same, -> G = 0 */
        psEnc->sCmn.LBRR_GainIncreases = SKP_max_int( 8 - SKP_RSHIFT( psEnc->sCmn.PacketLoss_perc, 1 ), 0 );

        /* Set main stream rate compensation */
        if( psEnc->sCmn.LBRR_enabled && psEnc->sCmn.PacketLoss_perc > LBRR_LOSS_THRES ) {
            /* Tuned to give approx same mean / weighted bitrate as no inband FEC */
            psEnc->inBandFEC_SNR_comp_Q8 = SKP_FIX_CONST( 6.0f, 8 ) - SKP_LSHIFT( psEnc->sCmn.LBRR_GainIncreases, 7 );
        } else {
            psEnc->inBandFEC_SNR_comp_Q8 = 0;
            psEnc->sCmn.LBRR_enabled     = 0;
        }
    } else {
        psEnc->inBandFEC_SNR_comp_Q8     = 0;
        psEnc->sCmn.LBRR_enabled         = 0;
    }
#else
    if( INBandFEC_enabled != 0 ) {
        ret = SKP_SILK_ENC_INVALID_INBAND_FEC_SETTING;
    }
    psEnc->sCmn.LBRR_enabled = 0;
#endif
    return ret;
}