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#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "main.h"

#include "stack_alloc.h"

/* Silk VAD noise level estimation */

# if !defined(OPUS_X86_MAY_HAVE_SSE4_1)

static OPUS_INLINE void silk_VAD_GetNoiseLevels(

    const opus_int32             pX[ VAD_N_BANDS ], /* I    subband energies                            */

    silk_VAD_state              *psSilk_VAD         /* I/O  Pointer to Silk VAD state                   */

);

#endif

/**********************************/

/* Initialization of the Silk VAD */

/**********************************/

opus_int silk_VAD_Init(                                         /* O    Return value, 0 if success                  */

    silk_VAD_state              *psSilk_VAD                     /* I/O  Pointer to Silk VAD state                   */

)

{

    opus_int b, ret = 0;

    /* reset state memory */

    silk_memset( psSilk_VAD, 0, sizeof( silk_VAD_state ) );

    /* init noise levels */

    /* Initialize array with approx pink noise levels (psd proportional to inverse of frequency) */

    for( b = 0; b < VAD_N_BANDS; b++ ) {

        psSilk_VAD->NoiseLevelBias[ b ] = silk_max_32( silk_DIV32_16( VAD_NOISE_LEVELS_BIAS, b + 1 ), 1 );

    }

    /* Initialize state */

    for( b = 0; b < VAD_N_BANDS; b++ ) {

        psSilk_VAD->NL[ b ]     = silk_MUL( 100, psSilk_VAD->NoiseLevelBias[ b ] );

        psSilk_VAD->inv_NL[ b ] = silk_DIV32( silk_int32_MAX, psSilk_VAD->NL[ b ] );

    }

    psSilk_VAD->counter = 15;

    /* init smoothed energy-to-noise ratio*/

    for( b = 0; b < VAD_N_BANDS; b++ ) {

        psSilk_VAD->NrgRatioSmth_Q8[ b ] = 100 * 256;       /* 100 * 256 --> 20 dB SNR */

    }

    return( ret );

}

/* Weighting factors for tilt measure */

static const opus_int32 tiltWeights[ VAD_N_BANDS ] = { 30000, 6000, -12000, -12000 };

/***************************************/

/* Get the speech activity level in Q8 */

/***************************************/

opus_int silk_VAD_GetSA_Q8_c(                                   /* O    Return value, 0 if success                  */

    silk_encoder_state          *psEncC,                        /* I/O  Encoder state                               */

    const opus_int16            pIn[]                           /* I    PCM input                                   */

)

{

    opus_int   SA_Q15, pSNR_dB_Q7, input_tilt;

    opus_int   decimated_framelength1, decimated_framelength2;

    opus_int   decimated_framelength;

    opus_int   dec_subframe_length, dec_subframe_offset, SNR_Q7, i, b, s;

    opus_int32 sumSquared, smooth_coef_Q16;

    opus_int16 HPstateTmp;

    VARDECL( opus_int16, X );

    opus_int32 Xnrg[ VAD_N_BANDS ];

    opus_int32 NrgToNoiseRatio_Q8[ VAD_N_BANDS ];

    opus_int32 speech_nrg, x_tmp;

    opus_int   X_offset[ VAD_N_BANDS ];

    opus_int   ret = 0;

    silk_VAD_state *psSilk_VAD = &psEncC->sVAD;

    SAVE_STACK;

    /* Safety checks */

    silk_assert( VAD_N_BANDS == 4 );

    celt_assert( MAX_FRAME_LENGTH >= psEncC->frame_length );

    celt_assert( psEncC->frame_length <= 512 );

    celt_assert( psEncC->frame_length == 8 * silk_RSHIFT( psEncC->frame_length, 3 ) );

    /***********************/

    /* Filter and Decimate */

    /***********************/

    decimated_framelength1 = silk_RSHIFT( psEncC->frame_length, 1 );

    decimated_framelength2 = silk_RSHIFT( psEncC->frame_length, 2 );

    decimated_framelength = silk_RSHIFT( psEncC->frame_length, 3 );

    /* Decimate into 4 bands:

       0       L      3L       L              3L                             5L

               -      --       -              --                             --

               8       8       2               4                              4

       [0-1 kHz| temp. |1-2 kHz|    2-4 kHz    |            4-8 kHz           |

       They're arranged to allow the minimal ( frame_length / 4 ) extra

       scratch space during the downsampling process */

    X_offset[ 0 ] = 0;

    X_offset[ 1 ] = decimated_framelength + decimated_framelength2;

    X_offset[ 2 ] = X_offset[ 1 ] + decimated_framelength;

    X_offset[ 3 ] = X_offset[ 2 ] + decimated_framelength2;

    ALLOC( X, X_offset[ 3 ] + decimated_framelength1, opus_int16 );

    /* 0-8 kHz to 0-4 kHz and 4-8 kHz */

    silk_ana_filt_bank_1( pIn, &psSilk_VAD->AnaState[  0 ],

        X, &X[ X_offset[ 3 ] ], psEncC->frame_length );

    /* 0-4 kHz to 0-2 kHz and 2-4 kHz */

    silk_ana_filt_bank_1( X, &psSilk_VAD->AnaState1[ 0 ],

        X, &X[ X_offset[ 2 ] ], decimated_framelength1 );

    /* 0-2 kHz to 0-1 kHz and 1-2 kHz */

    silk_ana_filt_bank_1( X, &psSilk_VAD->AnaState2[ 0 ],

        X, &X[ X_offset[ 1 ] ], decimated_framelength2 );

    /*********************************************/

    /* HP filter on lowest band (differentiator) */

    /*********************************************/

    X[ decimated_framelength - 1 ] = silk_RSHIFT( X[ decimated_framelength - 1 ], 1 );

    HPstateTmp = X[ decimated_framelength - 1 ];

    for( i = decimated_framelength - 1; i > 0; i-- ) {

        X[ i - 1 ]  = silk_RSHIFT( X[ i - 1 ], 1 );

        X[ i ]     -= X[ i - 1 ];

    }

    X[ 0 ] -= psSilk_VAD->HPstate;

    psSilk_VAD->HPstate = HPstateTmp;

    /*************************************/

    /* Calculate the energy in each band */

    /*************************************/

    for( b = 0; b < VAD_N_BANDS; b++ ) {

        /* Find the decimated framelength in the non-uniformly divided bands */

        decimated_framelength = silk_RSHIFT( psEncC->frame_length, silk_min_int( VAD_N_BANDS - b, VAD_N_BANDS - 1 ) );

        /* Split length into subframe lengths */

        dec_subframe_length = silk_RSHIFT( decimated_framelength, VAD_INTERNAL_SUBFRAMES_LOG2 );

        dec_subframe_offset = 0;

        /* Compute energy per sub-frame */

        /* initialize with summed energy of last subframe */

        Xnrg[ b ] = psSilk_VAD->XnrgSubfr[ b ];

        for( s = 0; s < VAD_INTERNAL_SUBFRAMES; s++ ) {

            sumSquared = 0;

            for( i = 0; i < dec_subframe_length; i++ ) {

                /* The energy will be less than dec_subframe_length * ( silk_int16_MIN / 8 ) ^ 2.            */

                /* Therefore we can accumulate with no risk of overflow (unless dec_subframe_length > 128)  */

                x_tmp = silk_RSHIFT(

                    X[ X_offset[ b ] + i + dec_subframe_offset ], 3 );

                sumSquared = silk_SMLABB( sumSquared, x_tmp, x_tmp );

                /* Safety check */

                silk_assert( sumSquared >= 0 );

            }

            /* Add/saturate summed energy of current subframe */

            if( s < VAD_INTERNAL_SUBFRAMES - 1 ) {

                Xnrg[ b ] = silk_ADD_POS_SAT32( Xnrg[ b ], sumSquared );

            } else {

                /* Look-ahead subframe */

                Xnrg[ b ] = silk_ADD_POS_SAT32( Xnrg[ b ], silk_RSHIFT( sumSquared, 1 ) );

            }

            dec_subframe_offset += dec_subframe_length;

        }

        psSilk_VAD->XnrgSubfr[ b ] = sumSquared;

    }

    /********************/

    /* Noise estimation */

    /********************/

    silk_VAD_GetNoiseLevels( &Xnrg[ 0 ], psSilk_VAD );

    /***********************************************/

    /* Signal-plus-noise to noise ratio estimation */

    /***********************************************/

    sumSquared = 0;

    input_tilt = 0;

    for( b = 0; b < VAD_N_BANDS; b++ ) {

        speech_nrg = Xnrg[ b ] - psSilk_VAD->NL[ b ];

        if( speech_nrg > 0 ) {

            /* Divide, with sufficient resolution */

            if( ( Xnrg[ b ] & 0xFF800000 ) == 0 ) {

                NrgToNoiseRatio_Q8[ b ] = silk_DIV32( silk_LSHIFT( Xnrg[ b ], 8 ), psSilk_VAD->NL[ b ] + 1 );

            } else {

                NrgToNoiseRatio_Q8[ b ] = silk_DIV32( Xnrg[ b ], silk_RSHIFT( psSilk_VAD->NL[ b ], 8 ) + 1 );

            }

            /* Convert to log domain */

            SNR_Q7 = silk_lin2log( NrgToNoiseRatio_Q8[ b ] ) - 8 * 128;

            /* Sum-of-squares */

            sumSquared = silk_SMLABB( sumSquared, SNR_Q7, SNR_Q7 );          /* Q14 */

            /* Tilt measure */

            if( speech_nrg < ( (opus_int32)1 << 20 ) ) {

                /* Scale down SNR value for small subband speech energies */

                SNR_Q7 = silk_SMULWB( silk_LSHIFT( silk_SQRT_APPROX( speech_nrg ), 6 ), SNR_Q7 );

            }

            input_tilt = silk_SMLAWB( input_tilt, tiltWeights[ b ], SNR_Q7 );

        } else {

            NrgToNoiseRatio_Q8[ b ] = 256;

        }

    }

    /* Mean-of-squares */

    sumSquared = silk_DIV32_16( sumSquared, VAD_N_BANDS ); /* Q14 */

    /* Root-mean-square approximation, scale to dBs, and write to output pointer */

    pSNR_dB_Q7 = (opus_int16)( 3 * silk_SQRT_APPROX( sumSquared ) ); /* Q7 */

    /*********************************/

    /* Speech Probability Estimation */

    /*********************************/

    SA_Q15 = silk_sigm_Q15( silk_SMULWB( VAD_SNR_FACTOR_Q16, pSNR_dB_Q7 ) - VAD_NEGATIVE_OFFSET_Q5 );

    /**************************/

    /* Frequency Tilt Measure */

    /**************************/

    psEncC->input_tilt_Q15 = silk_LSHIFT( silk_sigm_Q15( input_tilt ) - 16384, 1 );

    /**************************************************/

    /* Scale the sigmoid output based on power levels */

    /**************************************************/

    speech_nrg = 0;

    for( b = 0; b < VAD_N_BANDS; b++ ) {

        /* Accumulate signal-without-noise energies, higher frequency bands have more weight */

        speech_nrg += ( b + 1 ) * silk_RSHIFT( Xnrg[ b ] - psSilk_VAD->NL[ b ], 4 );

    }

    if( psEncC->frame_length == 20 * psEncC->fs_kHz ) {

        speech_nrg = silk_RSHIFT32( speech_nrg, 1 );

    }

    /* Power scaling */

    if( speech_nrg <= 0 ) {

        SA_Q15 = silk_RSHIFT( SA_Q15, 1 );

    } else if( speech_nrg < 16384 ) {

        speech_nrg = silk_LSHIFT32( speech_nrg, 16 );

        /* square-root */

        speech_nrg = silk_SQRT_APPROX( speech_nrg );

        SA_Q15 = silk_SMULWB( 32768 + speech_nrg, SA_Q15 );

    }

    /* Copy the resulting speech activity in Q8 */

    psEncC->speech_activity_Q8 = silk_min_int( silk_RSHIFT( SA_Q15, 7 ), silk_uint8_MAX );

    /***********************************/

    /* Energy Level and SNR estimation */

    /***********************************/

    /* Smoothing coefficient */

    smooth_coef_Q16 = silk_SMULWB( VAD_SNR_SMOOTH_COEF_Q18, silk_SMULWB( (opus_int32)SA_Q15, SA_Q15 ) );

    if( psEncC->frame_length == 10 * psEncC->fs_kHz ) {

        smooth_coef_Q16 >>= 1;

    }

    for( b = 0; b < VAD_N_BANDS; b++ ) {

        /* compute smoothed energy-to-noise ratio per band */

        psSilk_VAD->NrgRatioSmth_Q8[ b ] = silk_SMLAWB( psSilk_VAD->NrgRatioSmth_Q8[ b ],

            NrgToNoiseRatio_Q8[ b ] - psSilk_VAD->NrgRatioSmth_Q8[ b ], smooth_coef_Q16 );

        /* signal to noise ratio in dB per band */

        SNR_Q7 = 3 * ( silk_lin2log( psSilk_VAD->NrgRatioSmth_Q8[b] ) - 8 * 128 );

        /* quality = sigmoid( 0.25 * ( SNR_dB - 16 ) ); */

        psEncC->input_quality_bands_Q15[ b ] = silk_sigm_Q15( silk_RSHIFT( SNR_Q7 - 16 * 128, 4 ) );

    }

    RESTORE_STACK;

    return( ret );

}

/**************************/

/* Noise level estimation */

/**************************/

# if  !defined(OPUS_X86_MAY_HAVE_SSE4_1)

static OPUS_INLINE

#endif

void silk_VAD_GetNoiseLevels(

    const opus_int32            pX[ VAD_N_BANDS ],  /* I    subband energies                            */

    silk_VAD_state              *psSilk_VAD         /* I/O  Pointer to Silk VAD state                   */

)

{

    opus_int   k;

    opus_int32 nl, nrg, inv_nrg;

    opus_int   coef, min_coef;

    /* Initially faster smoothing */

    if( psSilk_VAD->counter < 1000 ) { /* 1000 = 20 sec */

        min_coef = silk_DIV32_16( silk_int16_MAX, silk_RSHIFT( psSilk_VAD->counter, 4 ) + 1 );

    } else {

        min_coef = 0;

    }

    for( k = 0; k < VAD_N_BANDS; k++ ) {

        /* Get old noise level estimate for current band */

        nl = psSilk_VAD->NL[ k ];

        silk_assert( nl >= 0 );

        /* Add bias */

        nrg = silk_ADD_POS_SAT32( pX[ k ], psSilk_VAD->NoiseLevelBias[ k ] );

        silk_assert( nrg > 0 );

        /* Invert energies */

        inv_nrg = silk_DIV32( silk_int32_MAX, nrg );

        silk_assert( inv_nrg >= 0 );

        /* Less update when subband energy is high */

        if( nrg > silk_LSHIFT( nl, 3 ) ) {

            coef = VAD_NOISE_LEVEL_SMOOTH_COEF_Q16 >> 3;

        } else if( nrg < nl ) {

            coef = VAD_NOISE_LEVEL_SMOOTH_COEF_Q16;

        } else {

            coef = silk_SMULWB( silk_SMULWW( inv_nrg, nl ), VAD_NOISE_LEVEL_SMOOTH_COEF_Q16 << 1 );

        }

        /* Initially faster smoothing */

        coef = silk_max_int( coef, min_coef );

        /* Smooth inverse energies */

        psSilk_VAD->inv_NL[ k ] = silk_SMLAWB( psSilk_VAD->inv_NL[ k ], inv_nrg - psSilk_VAD->inv_NL[ k ], coef );

        silk_assert( psSilk_VAD->inv_NL[ k ] >= 0 );

        /* Compute noise level by inverting again */

        nl = silk_DIV32( silk_int32_MAX, psSilk_VAD->inv_NL[ k ] );

        silk_assert( nl >= 0 );

        /* Limit noise levels (guarantee 7 bits of head room) */

        nl = silk_min( nl, 0x00FFFFFF );

        /* Store as part of state */

        psSilk_VAD->NL[ k ] = nl;

    }

    /* Increment frame counter */

    psSilk_VAD->counter++;

}