/* Prefilter for finding Quantizer input signal */
static OPUS_INLINE void silk_prefilt_FIX(
        silk_prefilter_state_FIX *P,                         /* I/O  state                               */
        opus_int32 st_res_Q12[],               /* I    short term residual signal          */
        opus_int32 xw_Q3[],                    /* O    prefiltered signal                  */
        opus_int32 HarmShapeFIRPacked_Q12,     /* I    Harmonic shaping coeficients        */
        opus_int Tilt_Q14,                   /* I    Tilt shaping coeficient             */
        opus_int32 LF_shp_Q14,                 /* I    Low-frequancy shaping coeficients   */
        opus_int lag,                        /* I    Lag for harmonic shaping            */
        opus_int length                      /* I    Length of signals                   */
) {
    opus_int i, idx, LTP_shp_buf_idx;
    opus_int32 n_LTP_Q12, n_Tilt_Q10, n_LF_Q10;
    opus_int32 sLF_MA_shp_Q12, sLF_AR_shp_Q12;
    opus_int16 *LTP_shp_buf;

    /* To speed up use temp variables instead of using the struct */
    LTP_shp_buf = P->sLTP_shp;
    LTP_shp_buf_idx = P->sLTP_shp_buf_idx;
    sLF_AR_shp_Q12 = P->sLF_AR_shp_Q12;
    sLF_MA_shp_Q12 = P->sLF_MA_shp_Q12;

    for (i = 0; i < length; i++) {
        if (lag > 0) {
            /* unrolled loop */
            silk_assert(HARM_SHAPE_FIR_TAPS == 3);
            idx = lag + LTP_shp_buf_idx;
            n_LTP_Q12 = silk_SMULBB(LTP_shp_buf[(idx - HARM_SHAPE_FIR_TAPS / 2 - 1) & LTP_MASK],
                                    HarmShapeFIRPacked_Q12);
            n_LTP_Q12 = silk_SMLABT(n_LTP_Q12,
                                    LTP_shp_buf[(idx - HARM_SHAPE_FIR_TAPS / 2) & LTP_MASK],
                                    HarmShapeFIRPacked_Q12);
            n_LTP_Q12 = silk_SMLABB(n_LTP_Q12,
                                    LTP_shp_buf[(idx - HARM_SHAPE_FIR_TAPS / 2 + 1) & LTP_MASK],
                                    HarmShapeFIRPacked_Q12);
        } else {
            n_LTP_Q12 = 0;
        }

        n_Tilt_Q10 = silk_SMULWB(sLF_AR_shp_Q12, Tilt_Q14);
        n_LF_Q10 = silk_SMLAWB(silk_SMULWT(sLF_AR_shp_Q12, LF_shp_Q14), sLF_MA_shp_Q12, LF_shp_Q14);

        sLF_AR_shp_Q12 = silk_SUB32(st_res_Q12[i], silk_LSHIFT(n_Tilt_Q10, 2));
        sLF_MA_shp_Q12 = silk_SUB32(sLF_AR_shp_Q12, silk_LSHIFT(n_LF_Q10, 2));

        LTP_shp_buf_idx = (LTP_shp_buf_idx - 1) & LTP_MASK;
        LTP_shp_buf[LTP_shp_buf_idx] = (opus_int16) silk_SAT16(
                silk_RSHIFT_ROUND(sLF_MA_shp_Q12, 12));

        xw_Q3[i] = silk_RSHIFT_ROUND(silk_SUB32(sLF_MA_shp_Q12, n_LTP_Q12), 9);
    }

    /* Copy temp variable back to state */
    P->sLF_AR_shp_Q12 = sLF_AR_shp_Q12;
    P->sLF_MA_shp_Q12 = sLF_MA_shp_Q12;
    P->sLTP_shp_buf_idx = LTP_shp_buf_idx;
}
Exemple #2
0
/* Convert adaptive Mid/Side representation to Left/Right stereo signal */
void silk_stereo_MS_to_LR(
    stereo_dec_state            *state,                         /* I/O  State                                       */
    opus_int16                  x1[],                           /* I/O  Left input signal, becomes mid signal       */
    opus_int16                  x2[],                           /* I/O  Right input signal, becomes side signal     */
    const opus_int32            pred_Q13[],                     /* I    Predictors                                  */
    opus_int                    fs_kHz,                         /* I    Samples rate (kHz)                          */
    opus_int                    frame_length                    /* I    Number of samples                           */
)
{
    opus_int   n, denom_Q16, delta0_Q13, delta1_Q13;
    opus_int32 sum, diff, pred0_Q13, pred1_Q13;

    /* Buffering */
    silk_memcpy( x1, state->sMid,  2 * sizeof( opus_int16 ) );
    silk_memcpy( x2, state->sSide, 2 * sizeof( opus_int16 ) );
    silk_memcpy( state->sMid,  &x1[ frame_length ], 2 * sizeof( opus_int16 ) );
    silk_memcpy( state->sSide, &x2[ frame_length ], 2 * sizeof( opus_int16 ) );

    /* Interpolate predictors and add prediction to side channel */
    pred0_Q13  = state->pred_prev_Q13[ 0 ];
    pred1_Q13  = state->pred_prev_Q13[ 1 ];
    denom_Q16  = silk_DIV32_16( (opus_int32)1 << 16, STEREO_INTERP_LEN_MS * fs_kHz );
    delta0_Q13 = silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 0 ] - state->pred_prev_Q13[ 0 ], denom_Q16 ), 16 );
    delta1_Q13 = silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 1 ] - state->pred_prev_Q13[ 1 ], denom_Q16 ), 16 );
    for( n = 0; n < STEREO_INTERP_LEN_MS * fs_kHz; n++ ) {
        pred0_Q13 += delta0_Q13;
        pred1_Q13 += delta1_Q13;
        sum = silk_LSHIFT( silk_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 );       /* Q11 */
        sum = silk_SMLAWB( silk_LSHIFT( (opus_int32)x2[ n + 1 ], 8 ), sum, pred0_Q13 );         /* Q8  */
        sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)x1[ n + 1 ], 11 ), pred1_Q13 );        /* Q8  */
        x2[ n + 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) );
    }
    pred0_Q13 = pred_Q13[ 0 ];
    pred1_Q13 = pred_Q13[ 1 ];
    for( n = STEREO_INTERP_LEN_MS * fs_kHz; n < frame_length; n++ ) {
        sum = silk_LSHIFT( silk_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 );       /* Q11 */
        sum = silk_SMLAWB( silk_LSHIFT( (opus_int32)x2[ n + 1 ], 8 ), sum, pred0_Q13 );         /* Q8  */
        sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)x1[ n + 1 ], 11 ), pred1_Q13 );        /* Q8  */
        x2[ n + 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) );
    }
    state->pred_prev_Q13[ 0 ] = pred_Q13[ 0 ];
    state->pred_prev_Q13[ 1 ] = pred_Q13[ 1 ];

    /* Convert to left/right signals */
    for( n = 0; n < frame_length; n++ ) {
        sum  = x1[ n + 1 ] + (opus_int32)x2[ n + 1 ];
        diff = x1[ n + 1 ] - (opus_int32)x2[ n + 1 ];
        x1[ n + 1 ] = (opus_int16)silk_SAT16( sum );
        x2[ n + 1 ] = (opus_int16)silk_SAT16( diff );
    }
}
static OPUS_INLINE opus_int16 *silk_resampler_private_IIR_FIR_INTERPOL(
    opus_int16  *out,
    opus_int16  *buf,
    opus_int32  max_index_Q16,
    opus_int32  index_increment_Q16
)
{
    opus_int32 index_Q16, res_Q15;
    opus_int16 *buf_ptr;
    opus_int32 table_index;

    /* Interpolate upsampled signal and store in output array */
    for( index_Q16 = 0; index_Q16 < max_index_Q16; index_Q16 += index_increment_Q16 ) {
        table_index = silk_SMULWB( index_Q16 & 0xFFFF, 12 );
        buf_ptr = &buf[ index_Q16 >> 16 ];

        res_Q15 = silk_SMULBB(          buf_ptr[ 0 ], silk_resampler_frac_FIR_12[      table_index ][ 0 ] );
        res_Q15 = silk_SMLABB( res_Q15, buf_ptr[ 1 ], silk_resampler_frac_FIR_12[      table_index ][ 1 ] );
        res_Q15 = silk_SMLABB( res_Q15, buf_ptr[ 2 ], silk_resampler_frac_FIR_12[      table_index ][ 2 ] );
        res_Q15 = silk_SMLABB( res_Q15, buf_ptr[ 3 ], silk_resampler_frac_FIR_12[      table_index ][ 3 ] );
        res_Q15 = silk_SMLABB( res_Q15, buf_ptr[ 4 ], silk_resampler_frac_FIR_12[ 11 - table_index ][ 3 ] );
        res_Q15 = silk_SMLABB( res_Q15, buf_ptr[ 5 ], silk_resampler_frac_FIR_12[ 11 - table_index ][ 2 ] );
        res_Q15 = silk_SMLABB( res_Q15, buf_ptr[ 6 ], silk_resampler_frac_FIR_12[ 11 - table_index ][ 1 ] );
        res_Q15 = silk_SMLABB( res_Q15, buf_ptr[ 7 ], silk_resampler_frac_FIR_12[ 11 - table_index ][ 0 ] );
        *out++ = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( res_Q15, 15 ) );
    }
    return out;
}
/* Processing of gains */
void silk_process_gains_FIX(
    silk_encoder_state_FIX          *psEnc,                                 /* I/O  Encoder state                                                               */
    silk_encoder_control_FIX        *psEncCtrl,                             /* I/O  Encoder control                                                             */
    opus_int                        condCoding                              /* I    The type of conditional coding to use                                       */
)
{
    silk_shape_state_FIX *psShapeSt = &psEnc->sShape;
    opus_int     k;
    opus_int32   s_Q16, InvMaxSqrVal_Q16, gain, gain_squared, ResNrg, ResNrgPart, quant_offset_Q10;

    /* Gain reduction when LTP coding gain is high */
    if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
        /*s = -0.5f * silk_sigmoid( 0.25f * ( psEncCtrl->LTPredCodGain - 12.0f ) ); */
        s_Q16 = -silk_sigm_Q15( silk_RSHIFT_ROUND( psEncCtrl->LTPredCodGain_Q7 - SILK_FIX_CONST( 12.0, 7 ), 4 ) );
        for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
            psEncCtrl->Gains_Q16[ k ] = silk_SMLAWB( psEncCtrl->Gains_Q16[ k ], psEncCtrl->Gains_Q16[ k ], s_Q16 );
        }
    }

    /* Limit the quantized signal */
    /* InvMaxSqrVal = pow( 2.0f, 0.33f * ( 21.0f - SNR_dB ) ) / subfr_length; */
    InvMaxSqrVal_Q16 = silk_DIV32_16( silk_log2lin(
        silk_SMULWB( SILK_FIX_CONST( 21 + 16 / 0.33, 7 ) - psEnc->sCmn.SNR_dB_Q7, SILK_FIX_CONST( 0.33, 16 ) ) ), psEnc->sCmn.subfr_length );

    for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
        /* Soft limit on ratio residual energy and squared gains */
        ResNrg     = psEncCtrl->ResNrg[ k ];
        ResNrgPart = silk_SMULWW( ResNrg, InvMaxSqrVal_Q16 );
        if( psEncCtrl->ResNrgQ[ k ] > 0 ) {
            ResNrgPart = silk_RSHIFT_ROUND( ResNrgPart, psEncCtrl->ResNrgQ[ k ] );
        } else {
            if( ResNrgPart >= silk_RSHIFT( silk_int32_MAX, -psEncCtrl->ResNrgQ[ k ] ) ) {
                ResNrgPart = silk_int32_MAX;
            } else {
                ResNrgPart = silk_LSHIFT( ResNrgPart, -psEncCtrl->ResNrgQ[ k ] );
            }
        }
        gain = psEncCtrl->Gains_Q16[ k ];
        gain_squared = silk_ADD_SAT32( ResNrgPart, silk_SMMUL( gain, gain ) );
        if( gain_squared < silk_int16_MAX ) {
            /* recalculate with higher precision */
            gain_squared = silk_SMLAWW( silk_LSHIFT( ResNrgPart, 16 ), gain, gain );
            silk_assert( gain_squared > 0 );
            gain = silk_SQRT_APPROX( gain_squared );                    /* Q8   */
            gain = silk_min( gain, silk_int32_MAX >> 8 );
            psEncCtrl->Gains_Q16[ k ] = silk_LSHIFT_SAT32( gain, 8 );   /* Q16  */
        } else {
/* Convert int32 coefficients to int16 coefs and make sure there's no wrap-around */
void silk_LPC_fit(
    opus_int16                  *a_QOUT,            /* O    Output signal                                               */
    opus_int32                    *a_QIN,             /* I/O  Input signal                                                */
    const opus_int              QOUT,               /* I    Input Q domain                                              */
    const opus_int              QIN,                /* I    Input Q domain                                              */
    const opus_int              d                   /* I    Filter order                                                */
)
{
    opus_int    i, k, idx = 0;
    opus_int32    maxabs, absval, chirp_Q16;

    /* Limit the maximum absolute value of the prediction coefficients, so that they'll fit in int16 */
    for( i = 0; i < 10; i++ ) {
        /* Find maximum absolute value and its index */
        maxabs = 0;
        for( k = 0; k < d; k++ ) {
            absval = silk_abs( a_QIN[k] );
            if( absval > maxabs ) {
                maxabs = absval;
                idx    = k;
            }
        }
        maxabs = silk_RSHIFT_ROUND( maxabs, QIN - QOUT );

        if( maxabs > silk_int16_MAX ) {
            /* Reduce magnitude of prediction coefficients */
            maxabs = silk_min( maxabs, 163838 );  /* ( silk_int32_MAX >> 14 ) + silk_int16_MAX = 163838 */
            chirp_Q16 = SILK_FIX_CONST( 0.999, 16 ) - silk_DIV32( silk_LSHIFT( maxabs - silk_int16_MAX, 14 ),
                                        silk_RSHIFT32( silk_MUL( maxabs, idx + 1), 2 ) );
            silk_bwexpander_32( a_QIN, d, chirp_Q16 );
        } else {
            break;
        }
    }

    if( i == 10 ) {
        /* Reached the last iteration, clip the coefficients */
        for( k = 0; k < d; k++ ) {
            a_QOUT[ k ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( a_QIN[ k ], QIN - QOUT ) );
            a_QIN[ k ] = silk_LSHIFT( (opus_int32)a_QOUT[ k ], QIN - QOUT );
        }
    } else {
        for( k = 0; k < d; k++ ) {
            a_QOUT[ k ] = (opus_int16)silk_RSHIFT_ROUND( a_QIN[ k ], QIN - QOUT );
        }
    }
}
Exemple #6
0
/* Uses SMULL(), available on armv4                                     */
opus_int32 silk_schur64(                            /* O    returns residual energy                                     */
    opus_int32                  rc_Q16[],           /* O    Reflection coefficients [order] Q16                         */
    const opus_int32            c[],                /* I    Correlations [order+1]                                      */
    opus_int32                  order               /* I    Prediction order                                            */
)
{
    opus_int   k, n;
    opus_int32 C[ SILK_MAX_ORDER_LPC + 1 ][ 2 ];
    opus_int32 Ctmp1_Q30, Ctmp2_Q30, rc_tmp_Q31;

    silk_assert( order==6||order==8||order==10||order==12||order==14||order==16 );

    /* Check for invalid input */
    if( c[ 0 ] <= 0 ) {
        silk_memset( rc_Q16, 0, order * sizeof( opus_int32 ) );
        return 0;
    }

    for( k = 0; k < order + 1; k++ ) {
        C[ k ][ 0 ] = C[ k ][ 1 ] = c[ k ];
    }

    for( k = 0; k < order; k++ ) {
        /* Check that we won't be getting an unstable rc, otherwise stop here. */
        if (silk_abs_int32(C[ k + 1 ][ 0 ]) >= C[ 0 ][ 1 ]) {
           if ( C[ k + 1 ][ 0 ] > 0 ) {
              rc_Q16[ k ] = -SILK_FIX_CONST( .99f, 16 );
           } else {
              rc_Q16[ k ] = SILK_FIX_CONST( .99f, 16 );
           }
           k++;
           break;
        }

        /* Get reflection coefficient: divide two Q30 values and get result in Q31 */
        rc_tmp_Q31 = silk_DIV32_varQ( -C[ k + 1 ][ 0 ], C[ 0 ][ 1 ], 31 );

        /* Save the output */
        rc_Q16[ k ] = silk_RSHIFT_ROUND( rc_tmp_Q31, 15 );

        /* Update correlations */
        for( n = 0; n < order - k; n++ ) {
            Ctmp1_Q30 = C[ n + k + 1 ][ 0 ];
            Ctmp2_Q30 = C[ n ][ 1 ];

            /* Multiply and add the highest int32 */
            C[ n + k + 1 ][ 0 ] = Ctmp1_Q30 + silk_SMMUL( silk_LSHIFT( Ctmp2_Q30, 1 ), rc_tmp_Q31 );
            C[ n ][ 1 ]         = Ctmp2_Q30 + silk_SMMUL( silk_LSHIFT( Ctmp1_Q30, 1 ), rc_tmp_Q31 );
        }
    }

    for(; k < order; k++ ) {
       rc_Q16[ k ] = 0;
    }

    return silk_max_32( 1, C[ 0 ][ 1 ] );
}
void silk_fit_LTP(
    opus_int32 LTP_coefs_Q16[ LTP_ORDER ],
    opus_int16 LTP_coefs_Q14[ LTP_ORDER ]
)
{
    opus_int i;

    for( i = 0; i < LTP_ORDER; i++ ) {
        LTP_coefs_Q14[ i ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( LTP_coefs_Q16[ i ], 2 ) );
    }
}
Exemple #8
0
/* Chirp (bandwidth expand) LP AR filter */
void silk_bwexpander(int16_t * ar,	/* I/O  AR filter to be expanded (without leading 1)                */
		     const int d,	/* I    Length of ar                                                */
		     int32_t chirp_Q16	/* I    Chirp factor (typically in the range 0 to 1)                */
    )
{
	int i;
	int32_t chirp_minus_one_Q16 = chirp_Q16 - 65536;

	/* NB: Dont use silk_SMULWB, instead of silk_RSHIFT_ROUND( silk_MUL(), 16 ), below.  */
	/* Bias in silk_SMULWB can lead to unstable filters                                */
	for (i = 0; i < d - 1; i++) {
		ar[i] =
		    (int16_t) silk_RSHIFT_ROUND(silk_MUL(chirp_Q16, ar[i]),
						   16);
		chirp_Q16 +=
		    silk_RSHIFT_ROUND(silk_MUL(chirp_Q16, chirp_minus_one_Q16),
				      16);
	}
	ar[d - 1] =
	    (int16_t) silk_RSHIFT_ROUND(silk_MUL(chirp_Q16, ar[d - 1]), 16);
}
Exemple #9
0
/* Second order ARMA filter, alternative implementation */
void silk_biquad_alt(const int16_t * in,	/* I     input signal                                               */
                     const int32_t * B_Q28,	/* I     MA coefficients [3]                                        */
                     const int32_t * A_Q28,	/* I     AR coefficients [2]                                        */
                     int32_t * S,	/* I/O   State vector [2]                                           */
                     int16_t * out,	/* O     output signal                                              */
                     const int32_t len,	/* I     signal length (must be even)                               */
                     int stride	/* I     Operate on interleaved signal if > 1                       */
                    )
{
    /* DIRECT FORM II TRANSPOSED (uses 2 element state vector) */
    int k;
    int32_t inval, A0_U_Q28, A0_L_Q28, A1_U_Q28, A1_L_Q28, out32_Q14;

    /* Negate A_Q28 values and split in two parts */
    A0_L_Q28 = (-A_Q28[0]) & 0x00003FFF;	/* lower part */
    A0_U_Q28 = silk_RSHIFT(-A_Q28[0], 14);	/* upper part */
    A1_L_Q28 = (-A_Q28[1]) & 0x00003FFF;	/* lower part */
    A1_U_Q28 = silk_RSHIFT(-A_Q28[1], 14);	/* upper part */

    for (k = 0; k < len; k++) {
        /* S[ 0 ], S[ 1 ]: Q12 */
        inval = in[k * stride];
        out32_Q14 = silk_LSHIFT(silk_SMLAWB(S[0], B_Q28[0], inval), 2);

        S[0] =
            S[1] + silk_RSHIFT_ROUND(silk_SMULWB(out32_Q14, A0_L_Q28),
                                     14);
        S[0] = silk_SMLAWB(S[0], out32_Q14, A0_U_Q28);
        S[0] = silk_SMLAWB(S[0], B_Q28[1], inval);

        S[1] = silk_RSHIFT_ROUND(silk_SMULWB(out32_Q14, A1_L_Q28), 14);
        S[1] = silk_SMLAWB(S[1], out32_Q14, A1_U_Q28);
        S[1] = silk_SMLAWB(S[1], B_Q28[2], inval);

        /* Scale back to Q0 and saturate */
        out[k * stride] =
            (int16_t)
            silk_SAT16(silk_RSHIFT(out32_Q14 + (1 << 14) - 1, 14));
    }
}
Exemple #10
0
static inline void silk_A2NLSF_init(
     const opus_int32    *a_Q16,
     opus_int32          *P,
     opus_int32          *Q,
     const opus_int      dd
)
{
    opus_int k;

    /* Convert filter coefs to even and odd polynomials */
    P[dd] = silk_LSHIFT( 1, QPoly );
    Q[dd] = silk_LSHIFT( 1, QPoly );
    for( k = 0; k < dd; k++ ) {
#if( QPoly < 16 )
        P[ k ] = silk_RSHIFT_ROUND( -a_Q16[ dd - k - 1 ] - a_Q16[ dd + k ], 16 - QPoly ); /* QPoly */
        Q[ k ] = silk_RSHIFT_ROUND( -a_Q16[ dd - k - 1 ] + a_Q16[ dd + k ], 16 - QPoly ); /* QPoly */
#elif( Qpoly == 16 )
        P[ k ] = -a_Q16[ dd - k - 1 ] - a_Q16[ dd + k ]; /* QPoly*/
        Q[ k ] = -a_Q16[ dd - k - 1 ] + a_Q16[ dd + k ]; /* QPoly*/
#else
        P[ k ] = silk_LSHIFT( -a_Q16[ dd - k - 1 ] - a_Q16[ dd + k ], QPoly - 16 ); /* QPoly */
        Q[ k ] = silk_LSHIFT( -a_Q16[ dd - k - 1 ] + a_Q16[ dd + k ], QPoly - 16 ); /* QPoly */
#endif
    }

    /* Divide out zeros as we have that for even filter orders, */
    /* z =  1 is always a root in Q, and                        */
    /* z = -1 is always a root in P                             */
    for( k = dd; k > 0; k-- ) {
        P[ k - 1 ] -= P[ k ];
        Q[ k - 1 ] += Q[ k ];
    }

    /* Transform polynomials from cos(n*f) to cos(f)^n */
    silk_A2NLSF_trans_poly( P, dd );
    silk_A2NLSF_trans_poly( Q, dd );
}
Exemple #11
0
/* Split signal into two decimated bands using first-order allpass filters */
void silk_ana_filt_bank_1(
    const opus_int16            *in,                /* I    Input signal [N]                                            */
    opus_int32                  *S,                 /* I/O  State vector [2]                                            */
    opus_int16                  *outL,              /* O    Low band [N/2]                                              */
    opus_int16                  *outH,              /* O    High band [N/2]                                             */
    const opus_int32            N                   /* I    Number of input samples                                     */
)
{
    opus_int      k, N2 = silk_RSHIFT( N, 1 );
    opus_int32    in32, X, Y, out_1, out_2;

    /* Internal variables and state are in Q10 format */
    for( k = 0; k < N2; k++ ) {
        /* Convert to Q10 */
        in32 = silk_LSHIFT( (opus_int32)in[ 2 * k ], 10 );

        /* All-pass section for even input sample */
        Y      = silk_SUB32( in32, S[ 0 ] );
        X      = silk_SMLAWB( Y, Y, A_fb1_21 );
        out_1  = silk_ADD32( S[ 0 ], X );
        S[ 0 ] = silk_ADD32( in32, X );

        /* Convert to Q10 */
        in32 = silk_LSHIFT( (opus_int32)in[ 2 * k + 1 ], 10 );

        /* All-pass section for odd input sample, and add to output of previous section */
        Y      = silk_SUB32( in32, S[ 1 ] );
        X      = silk_SMULWB( Y, A_fb1_20 );
        out_2  = silk_ADD32( S[ 1 ], X );
        S[ 1 ] = silk_ADD32( in32, X );

        /* Add/subtract, convert back to int16 and store to output */
        outL[ k ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( silk_ADD32( out_2, out_1 ), 11 ) );
        outH[ k ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( silk_SUB32( out_2, out_1 ), 11 ) );
    }
}
Exemple #12
0
/* Chirp (bandwidth expand) LP AR filter */
void silk_bwexpander_32(
    opus_int32                  *ar,                /* I/O  AR filter to be expanded (without leading 1)                */
    const opus_int              d,                  /* I    Length of ar                                                */
    opus_int32                  chirp_Q16           /* I    Chirp factor in Q16                                         */
)
{
    opus_int   i;
    opus_int32 chirp_minus_one_Q16 = chirp_Q16 - 65536;

    for( i = 0; i < d - 1; i++ ) {
        ar[ i ]    = silk_SMULWW( chirp_Q16, ar[ i ] );
        chirp_Q16 += silk_RSHIFT_ROUND( silk_MUL( chirp_Q16, chirp_minus_one_Q16 ), 16 );
    }
    ar[ d - 1 ] = silk_SMULWW( chirp_Q16, ar[ d - 1 ] );
}
void silk_LPC_analysis_filter(
    opus_int16                  *out,               /* O    Output signal                                               */
    const opus_int16            *in,                /* I    Input signal                                                */
    const opus_int16            *B,                 /* I    MA prediction coefficients, Q12 [order]                     */
    const opus_int32            len,                /* I    Signal length                                               */
    const opus_int32            d                   /* I    Filter order                                                */
)
{
    opus_int         ix, j;
    opus_int32       out32_Q12, out32;
    const opus_int16 *in_ptr;

    silk_assert( d >= 6 );
    silk_assert( (d & 1) == 0 );
    silk_assert( d <= len );

    for( ix = d; ix < len; ix++ ) {
        in_ptr = &in[ ix - 1 ];

        out32_Q12 = silk_SMULBB( in_ptr[  0 ], B[ 0 ] );
        /* Allowing wrap around so that two wraps can cancel each other. The rare
           cases where the result wraps around can only be triggered by invalid streams*/
        out32_Q12 = silk_SMLABB_ovflw( out32_Q12, in_ptr[ -1 ], B[ 1 ] );
        out32_Q12 = silk_SMLABB_ovflw( out32_Q12, in_ptr[ -2 ], B[ 2 ] );
        out32_Q12 = silk_SMLABB_ovflw( out32_Q12, in_ptr[ -3 ], B[ 3 ] );
        out32_Q12 = silk_SMLABB_ovflw( out32_Q12, in_ptr[ -4 ], B[ 4 ] );
        out32_Q12 = silk_SMLABB_ovflw( out32_Q12, in_ptr[ -5 ], B[ 5 ] );
        for( j = 6; j < d; j += 2 ) {
            out32_Q12 = silk_SMLABB_ovflw( out32_Q12, in_ptr[ -j     ], B[ j     ] );
            out32_Q12 = silk_SMLABB_ovflw( out32_Q12, in_ptr[ -j - 1 ], B[ j + 1 ] );
        }

        /* Subtract prediction */
        out32_Q12 = silk_SUB32_ovflw( silk_LSHIFT( (opus_int32)in_ptr[ 1 ], 12 ), out32_Q12 );

        /* Scale to Q0 */
        out32 = silk_RSHIFT_ROUND( out32_Q12, 12 );

        /* Saturate output */
        out[ ix ] = (opus_int16)silk_SAT16( out32 );
    }

    /* Set first d output samples to zero */
    silk_memset( out, 0, d * sizeof( opus_int16 ) );
}
void silk_noise_shape_analysis_FIX(
    silk_encoder_state_FIX          *psEnc,                                 /* I/O  Encoder state FIX                                                           */
    silk_encoder_control_FIX        *psEncCtrl,                             /* I/O  Encoder control FIX                                                         */
    const opus_int16                *pitch_res,                             /* I    LPC residual from pitch analysis                                            */
    const opus_int16                *x,                                     /* I    Input signal [ frame_length + la_shape ]                                    */
    int                              arch                                   /* I    Run-time architecture                                                       */
)
{
    silk_shape_state_FIX *psShapeSt = &psEnc->sShape;
    opus_int     k, i, nSamples, Qnrg, b_Q14, warping_Q16, scale = 0;
    opus_int32   SNR_adj_dB_Q7, HarmBoost_Q16, HarmShapeGain_Q16, Tilt_Q16, tmp32;
    opus_int32   nrg, pre_nrg_Q30, log_energy_Q7, log_energy_prev_Q7, energy_variation_Q7;
    opus_int32   delta_Q16, BWExp1_Q16, BWExp2_Q16, gain_mult_Q16, gain_add_Q16, strength_Q16, b_Q8;
    opus_int32   auto_corr[     MAX_SHAPE_LPC_ORDER + 1 ];
    opus_int32   refl_coef_Q16[ MAX_SHAPE_LPC_ORDER ];
    opus_int32   AR1_Q24[       MAX_SHAPE_LPC_ORDER ];
    opus_int32   AR2_Q24[       MAX_SHAPE_LPC_ORDER ];
    VARDECL( opus_int16, x_windowed );
    const opus_int16 *x_ptr, *pitch_res_ptr;
    SAVE_STACK;

    /* Point to start of first LPC analysis block */
    x_ptr = x - psEnc->sCmn.la_shape;

    /****************/
    /* GAIN CONTROL */
    /****************/
    SNR_adj_dB_Q7 = psEnc->sCmn.SNR_dB_Q7;

    /* Input quality is the average of the quality in the lowest two VAD bands */
    psEncCtrl->input_quality_Q14 = ( opus_int )silk_RSHIFT( (opus_int32)psEnc->sCmn.input_quality_bands_Q15[ 0 ]
        + psEnc->sCmn.input_quality_bands_Q15[ 1 ], 2 );

    /* Coding quality level, between 0.0_Q0 and 1.0_Q0, but in Q14 */
    psEncCtrl->coding_quality_Q14 = silk_RSHIFT( silk_sigm_Q15( silk_RSHIFT_ROUND( SNR_adj_dB_Q7 -
        SILK_FIX_CONST( 20.0, 7 ), 4 ) ), 1 );

    /* Reduce coding SNR during low speech activity */
    if( psEnc->sCmn.useCBR == 0 ) {
        b_Q8 = SILK_FIX_CONST( 1.0, 8 ) - psEnc->sCmn.speech_activity_Q8;
        b_Q8 = silk_SMULWB( silk_LSHIFT( b_Q8, 8 ), b_Q8 );
        SNR_adj_dB_Q7 = silk_SMLAWB( SNR_adj_dB_Q7,
            silk_SMULBB( SILK_FIX_CONST( -BG_SNR_DECR_dB, 7 ) >> ( 4 + 1 ), b_Q8 ),                                       /* Q11*/
            silk_SMULWB( SILK_FIX_CONST( 1.0, 14 ) + psEncCtrl->input_quality_Q14, psEncCtrl->coding_quality_Q14 ) );     /* Q12*/
    }
Exemple #15
0
void silk_warped_LPC_analysis_filter_FIX(
          opus_int32            state[],                    /* I/O  State [order + 1]                   */
          opus_int32            res_Q2[],                   /* O    Residual signal [length]            */
    const opus_int16            coef_Q13[],                 /* I    Coefficients [order]                */
    const opus_int16            input[],                    /* I    Input signal [length]               */
    const opus_int16            lambda_Q16,                 /* I    Warping factor                      */
    const opus_int              length,                     /* I    Length of input signal              */
    const opus_int              order                       /* I    Filter order (even)                 */
)
{
    opus_int     n, i;
    opus_int32   acc_Q11, tmp1, tmp2;

    /* Order must be even */
    silk_assert( ( order & 1 ) == 0 );

    for( n = 0; n < length; n++ ) {
        /* Output of lowpass section */
        tmp2 = silk_SMLAWB( state[ 0 ], state[ 1 ], lambda_Q16 );
        state[ 0 ] = silk_LSHIFT( input[ n ], 14 );
        /* Output of allpass section */
        tmp1 = silk_SMLAWB( state[ 1 ], state[ 2 ] - tmp2, lambda_Q16 );
        state[ 1 ] = tmp2;
        acc_Q11 = silk_RSHIFT( order, 1 );
        acc_Q11 = silk_SMLAWB( acc_Q11, tmp2, coef_Q13[ 0 ] );
        /* Loop over allpass sections */
        for( i = 2; i < order; i += 2 ) {
            /* Output of allpass section */
            tmp2 = silk_SMLAWB( state[ i ], state[ i + 1 ] - tmp1, lambda_Q16 );
            state[ i ] = tmp1;
            acc_Q11 = silk_SMLAWB( acc_Q11, tmp1, coef_Q13[ i - 1 ] );
            /* Output of allpass section */
            tmp1 = silk_SMLAWB( state[ i + 1 ], state[ i + 2 ] - tmp2, lambda_Q16 );
            state[ i + 1 ] = tmp2;
            acc_Q11 = silk_SMLAWB( acc_Q11, tmp2, coef_Q13[ i ] );
        }
        state[ order ] = tmp1;
        acc_Q11 = silk_SMLAWB( acc_Q11, tmp1, coef_Q13[ order - 1 ] );
        res_Q2[ n ] = silk_LSHIFT( (opus_int32)input[ n ], 2 ) - silk_RSHIFT_ROUND( acc_Q11, 9 );
    }
}
static inline opus_int16 *silk_resampler_private_down_FIR_INTERPOL(
    opus_int16          *out,
    opus_int32          *buf,
    const opus_int16    *FIR_Coefs,
    opus_int            FIR_Order,
    opus_int            FIR_Fracs,
    opus_int32          max_index_Q16,
    opus_int32          index_increment_Q16
)
{
    opus_int32 index_Q16, res_Q6;
    opus_int32 *buf_ptr;
    opus_int32 interpol_ind;
    const opus_int16 *interpol_ptr;

    switch( FIR_Order ) {
        case RESAMPLER_DOWN_ORDER_FIR0:
            for( index_Q16 = 0; index_Q16 < max_index_Q16; index_Q16 += index_increment_Q16 ) {
                /* Integer part gives pointer to buffered input */
                buf_ptr = buf + silk_RSHIFT( index_Q16, 16 );

                /* Fractional part gives interpolation coefficients */
                interpol_ind = silk_SMULWB( index_Q16 & 0xFFFF, FIR_Fracs );

                /* Inner product */
                interpol_ptr = &FIR_Coefs[ RESAMPLER_DOWN_ORDER_FIR0 / 2 * interpol_ind ];
                res_Q6 = silk_SMULWB(         buf_ptr[ 0 ], interpol_ptr[ 0 ] );
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 1 ], interpol_ptr[ 1 ] );
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 2 ], interpol_ptr[ 2 ] );
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 3 ], interpol_ptr[ 3 ] );
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 4 ], interpol_ptr[ 4 ] );
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 5 ], interpol_ptr[ 5 ] );
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 6 ], interpol_ptr[ 6 ] );
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 7 ], interpol_ptr[ 7 ] );
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 8 ], interpol_ptr[ 8 ] );
                interpol_ptr = &FIR_Coefs[ RESAMPLER_DOWN_ORDER_FIR0 / 2 * ( FIR_Fracs - 1 - interpol_ind ) ];
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 17 ], interpol_ptr[ 0 ] );
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 16 ], interpol_ptr[ 1 ] );
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 15 ], interpol_ptr[ 2 ] );
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 14 ], interpol_ptr[ 3 ] );
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 13 ], interpol_ptr[ 4 ] );
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 12 ], interpol_ptr[ 5 ] );
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 11 ], interpol_ptr[ 6 ] );
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 10 ], interpol_ptr[ 7 ] );
                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[  9 ], interpol_ptr[ 8 ] );

                /* Scale down, saturate and store in output array */
                *out++ = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( res_Q6, 6 ) );
            }
            break;
        case RESAMPLER_DOWN_ORDER_FIR1:
            for( index_Q16 = 0; index_Q16 < max_index_Q16; index_Q16 += index_increment_Q16 ) {
                /* Integer part gives pointer to buffered input */
                buf_ptr = buf + silk_RSHIFT( index_Q16, 16 );

                /* Inner product */
                res_Q6 = silk_SMULWB(         silk_ADD32( buf_ptr[  0 ], buf_ptr[ 23 ] ), FIR_Coefs[  0 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  1 ], buf_ptr[ 22 ] ), FIR_Coefs[  1 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  2 ], buf_ptr[ 21 ] ), FIR_Coefs[  2 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  3 ], buf_ptr[ 20 ] ), FIR_Coefs[  3 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  4 ], buf_ptr[ 19 ] ), FIR_Coefs[  4 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  5 ], buf_ptr[ 18 ] ), FIR_Coefs[  5 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  6 ], buf_ptr[ 17 ] ), FIR_Coefs[  6 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  7 ], buf_ptr[ 16 ] ), FIR_Coefs[  7 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  8 ], buf_ptr[ 15 ] ), FIR_Coefs[  8 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  9 ], buf_ptr[ 14 ] ), FIR_Coefs[  9 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 10 ], buf_ptr[ 13 ] ), FIR_Coefs[ 10 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 11 ], buf_ptr[ 12 ] ), FIR_Coefs[ 11 ] );

                /* Scale down, saturate and store in output array */
                *out++ = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( res_Q6, 6 ) );
            }
            break;
        case RESAMPLER_DOWN_ORDER_FIR2:
            for( index_Q16 = 0; index_Q16 < max_index_Q16; index_Q16 += index_increment_Q16 ) {
                /* Integer part gives pointer to buffered input */
                buf_ptr = buf + silk_RSHIFT( index_Q16, 16 );

                /* Inner product */
                res_Q6 = silk_SMULWB(         silk_ADD32( buf_ptr[  0 ], buf_ptr[ 35 ] ), FIR_Coefs[  0 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  1 ], buf_ptr[ 34 ] ), FIR_Coefs[  1 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  2 ], buf_ptr[ 33 ] ), FIR_Coefs[  2 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  3 ], buf_ptr[ 32 ] ), FIR_Coefs[  3 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  4 ], buf_ptr[ 31 ] ), FIR_Coefs[  4 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  5 ], buf_ptr[ 30 ] ), FIR_Coefs[  5 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  6 ], buf_ptr[ 29 ] ), FIR_Coefs[  6 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  7 ], buf_ptr[ 28 ] ), FIR_Coefs[  7 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  8 ], buf_ptr[ 27 ] ), FIR_Coefs[  8 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  9 ], buf_ptr[ 26 ] ), FIR_Coefs[  9 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 10 ], buf_ptr[ 25 ] ), FIR_Coefs[ 10 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 11 ], buf_ptr[ 24 ] ), FIR_Coefs[ 11 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 12 ], buf_ptr[ 23 ] ), FIR_Coefs[ 12 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 13 ], buf_ptr[ 22 ] ), FIR_Coefs[ 13 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 14 ], buf_ptr[ 21 ] ), FIR_Coefs[ 14 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 15 ], buf_ptr[ 20 ] ), FIR_Coefs[ 15 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 16 ], buf_ptr[ 19 ] ), FIR_Coefs[ 16 ] );
                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 17 ], buf_ptr[ 18 ] ), FIR_Coefs[ 17 ] );

                /* Scale down, saturate and store in output array */
                *out++ = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( res_Q6, 6 ) );
            }
            break;
        default:
            silk_assert( 0 );
    }
    return out;
}
Exemple #17
0
static 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    */
)
{
    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_Q16, inv_gain_Q30;
    opus_int32 energy1, energy2, *rand_ptr, *pred_lag_ptr;
    opus_int32 LPC_exc_Q14, LPC_pred_Q10, LTP_pred_Q12;
    opus_int16 rand_scale_Q14;
    opus_int16 *B_Q14, *exc_buf_ptr;
    opus_int32 *sLPC_Q14_ptr;
    opus_int16 exc_buf[ 2 * MAX_SUB_FRAME_LENGTH ];
    opus_int16 A_Q12[ MAX_LPC_ORDER ];
    opus_int16 sLTP[ MAX_FRAME_LENGTH ];
    opus_int32 sLTP_Q14[ 2 * MAX_FRAME_LENGTH ];
    silk_PLC_struct *psPLC = &psDec->sPLC;

    if (psDec->first_frame_after_reset)
       silk_memset(psPLC->prevLPC_Q12, 0, MAX_LPC_ORDER*sizeof(psPLC->prevLPC_Q12[ 0 ]));

    /* Find random noise component */
    /* Scale previous excitation signal */
    exc_buf_ptr = exc_buf;
    for( k = 0; k < 2; k++ ) {
        for( i = 0; i < psPLC->subfr_length; i++ ) {
            exc_buf_ptr[ i ] = ( opus_int16 )silk_RSHIFT(
                silk_SMULWW( psDec->exc_Q10[ i + ( k + psPLC->nb_subfr - 2 ) * psPLC->subfr_length ], psPLC->prevGain_Q16[ k ] ), 10 );
        }
        exc_buf_ptr += psPLC->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,                         psPLC->subfr_length );
    silk_sum_sqr_shift( &energy2, &shift2, &exc_buf[ psPLC->subfr_length ], psPLC->subfr_length );

    if( silk_RSHIFT( energy1, shift2 ) < silk_RSHIFT( energy2, shift1 ) ) {
        /* First sub-frame has lowest energy */
        rand_ptr = &psDec->exc_Q10[ silk_max_int( 0, ( psPLC->nb_subfr - 1 ) * psPLC->subfr_length - RAND_BUF_SIZE ) ];
    } else {
        /* Second sub-frame has lowest energy */
        rand_ptr = &psDec->exc_Q10[ silk_max_int( 0, psPLC->nb_subfr * psPLC->subfr_length - RAND_BUF_SIZE ) ];
    }

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

    /* Setup attenuation gains */
    harm_Gain_Q15 = HARM_ATT_Q15[ silk_min_int( NB_ATT - 1, psDec->lossCnt ) ];
    if( psDec->prevSignalType == TYPE_VOICED ) {
        rand_Gain_Q15 = PLC_RAND_ATTENUATE_V_Q15[  silk_min_int( NB_ATT - 1, psDec->lossCnt ) ];
    } else {
        rand_Gain_Q15 = PLC_RAND_ATTENUATE_UV_Q15[ silk_min_int( NB_ATT - 1, psDec->lossCnt ) ];
    }

    /* 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;

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

            down_scale_Q30 = silk_min_32( silk_RSHIFT( 1 << 30, LOG2_INV_LPC_GAIN_HIGH_THRES ), invGain_Q30 );
            down_scale_Q30 = silk_max_32( silk_RSHIFT( 1 << 30, LOG2_INV_LPC_GAIN_LOW_THRES ), down_scale_Q30 );
            down_scale_Q30 = silk_LSHIFT( down_scale_Q30, LOG2_INV_LPC_GAIN_HIGH_THRES );

            rand_Gain_Q15 = silk_RSHIFT( silk_SMULWB( down_scale_Q30, rand_Gain_Q15 ), 14 );
        }
    }

    rand_seed    = psPLC->rand_seed;
    lag          = silk_RSHIFT_ROUND( psPLC->pitchL_Q8, 8 );
    sLTP_buf_idx = psDec->ltp_mem_length;

    /* Rewhiten LTP state */
    idx = psDec->ltp_mem_length - lag - psDec->LPC_order - LTP_ORDER / 2;
    silk_assert( idx > 0 );
    silk_LPC_analysis_filter( &sLTP[ idx ], &psDec->outBuf[ idx ], A_Q12, psDec->ltp_mem_length - idx, psDec->LPC_order );
    /* Scale LTP state */
    inv_gain_Q16 = silk_INVERSE32_varQ( psPLC->prevGain_Q16[ 1 ], 32 );
    inv_gain_Q16 = silk_min( inv_gain_Q16, silk_int16_MAX );
    inv_gain_Q30 = silk_LSHIFT( inv_gain_Q16, 14 );
    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++ ) {
        /* Setup pointer */
        pred_lag_ptr = &sLTP_Q14[ sLTP_buf_idx - lag + LTP_ORDER / 2 ];
        for( i = 0; i < psDec->subfr_length; i++ ) {
            /* Unrolled loop */
            LTP_pred_Q12 = silk_SMULWB(               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;
            LPC_exc_Q14 = silk_LSHIFT32( silk_SMULWB( rand_ptr[ idx ], rand_scale_Q14 ), 6 ); /* Random noise part */
            LPC_exc_Q14 = silk_ADD32( LPC_exc_Q14, silk_LSHIFT32( LTP_pred_Q12, 2 ) );        /* Harmonic part */
            sLTP_Q14[ sLTP_buf_idx ] = LPC_exc_Q14;
            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 ) );

    silk_assert( psDec->LPC_order >= 10 ); /* check that unrolling works */
    for( i = 0; i < psDec->frame_length; i++ ) {
        /* partly unrolled */
        LPC_pred_Q10 = silk_SMULWB(               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_LSHIFT32( sLPC_Q14_ptr[ MAX_LPC_ORDER + i ], LPC_pred_Q10, 4 );

        /* Scale with Gain */
        frame[ i ] = ( opus_int16 )silk_SAT16( silk_RSHIFT_ROUND( silk_SMULWW( sLPC_Q14_ptr[ MAX_LPC_ORDER + i ], psPLC->prevGain_Q16[ 1 ] ), 14 ) );
    }

    /* 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;
    }
}
Exemple #18
0
/* encControl->payloadSize_ms is set to                                                                         */
opus_int silk_Encode(                                   /* O    Returns error code                              */
    void                            *encState,          /* I/O  State                                           */
    silk_EncControlStruct           *encControl,        /* I    Control status                                  */
    const opus_int16                *samplesIn,         /* I    Speech sample input vector                      */
    opus_int                        nSamplesIn,         /* I    Number of samples in input vector               */
    ec_enc                          *psRangeEnc,        /* I/O  Compressor data structure                       */
    opus_int32                      *nBytesOut,         /* I/O  Number of bytes in payload (input: Max bytes)   */
    const opus_int                  prefillFlag         /* I    Flag to indicate prefilling buffers no coding   */
)
{
    opus_int   n, i, nBits, flags, tmp_payloadSize_ms = 0, tmp_complexity = 0, ret = 0;
    opus_int   nSamplesToBuffer, nSamplesToBufferMax, nBlocksOf10ms;
    opus_int   nSamplesFromInput = 0, nSamplesFromInputMax;
    opus_int   speech_act_thr_for_switch_Q8;
    opus_int32 TargetRate_bps, MStargetRates_bps[ 2 ], channelRate_bps, LBRR_symbol, sum;
    silk_encoder *psEnc = ( silk_encoder * )encState;
    VARDECL( opus_int16, buf );
    opus_int transition, curr_block, tot_blocks;
    SAVE_STACK;

    if (encControl->reducedDependency)
    {
       psEnc->state_Fxx[0].sCmn.first_frame_after_reset = 1;
       psEnc->state_Fxx[1].sCmn.first_frame_after_reset = 1;
    }
    psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded = psEnc->state_Fxx[ 1 ].sCmn.nFramesEncoded = 0;

    /* Check values in encoder control structure */
    if( ( ret = check_control_input( encControl ) ) != 0 ) {
        silk_assert( 0 );
        RESTORE_STACK;
        return ret;
    }

    encControl->switchReady = 0;

    if( encControl->nChannelsInternal > psEnc->nChannelsInternal ) {
        /* Mono -> Stereo transition: init state of second channel and stereo state */
        ret += silk_init_encoder( &psEnc->state_Fxx[ 1 ], psEnc->state_Fxx[ 0 ].sCmn.arch );
        silk_memset( psEnc->sStereo.pred_prev_Q13, 0, sizeof( psEnc->sStereo.pred_prev_Q13 ) );
        silk_memset( psEnc->sStereo.sSide, 0, sizeof( psEnc->sStereo.sSide ) );
        psEnc->sStereo.mid_side_amp_Q0[ 0 ] = 0;
        psEnc->sStereo.mid_side_amp_Q0[ 1 ] = 1;
        psEnc->sStereo.mid_side_amp_Q0[ 2 ] = 0;
        psEnc->sStereo.mid_side_amp_Q0[ 3 ] = 1;
        psEnc->sStereo.width_prev_Q14 = 0;
        psEnc->sStereo.smth_width_Q14 = SILK_FIX_CONST( 1, 14 );
        if( psEnc->nChannelsAPI == 2 ) {
            silk_memcpy( &psEnc->state_Fxx[ 1 ].sCmn.resampler_state, &psEnc->state_Fxx[ 0 ].sCmn.resampler_state, sizeof( silk_resampler_state_struct ) );
            silk_memcpy( &psEnc->state_Fxx[ 1 ].sCmn.In_HP_State,     &psEnc->state_Fxx[ 0 ].sCmn.In_HP_State,     sizeof( psEnc->state_Fxx[ 1 ].sCmn.In_HP_State ) );
        }
    }

    transition = (encControl->payloadSize_ms != psEnc->state_Fxx[ 0 ].sCmn.PacketSize_ms) || (psEnc->nChannelsInternal != encControl->nChannelsInternal);

    psEnc->nChannelsAPI = encControl->nChannelsAPI;
    psEnc->nChannelsInternal = encControl->nChannelsInternal;

    nBlocksOf10ms = silk_DIV32( 100 * nSamplesIn, encControl->API_sampleRate );
    tot_blocks = ( nBlocksOf10ms > 1 ) ? nBlocksOf10ms >> 1 : 1;
    curr_block = 0;
    if( prefillFlag ) {
        /* Only accept input length of 10 ms */
        if( nBlocksOf10ms != 1 ) {
            silk_assert( 0 );
            RESTORE_STACK;
            return SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES;
        }
        /* Reset Encoder */
        for( n = 0; n < encControl->nChannelsInternal; n++ ) {
            ret = silk_init_encoder( &psEnc->state_Fxx[ n ], psEnc->state_Fxx[ n ].sCmn.arch );
            silk_assert( !ret );
        }
        tmp_payloadSize_ms = encControl->payloadSize_ms;
        encControl->payloadSize_ms = 10;
        tmp_complexity = encControl->complexity;
        encControl->complexity = 0;
        for( n = 0; n < encControl->nChannelsInternal; n++ ) {
            psEnc->state_Fxx[ n ].sCmn.controlled_since_last_payload = 0;
            psEnc->state_Fxx[ n ].sCmn.prefillFlag = 1;
        }
    } else {
        /* Only accept input lengths that are a multiple of 10 ms */
        if( nBlocksOf10ms * encControl->API_sampleRate != 100 * nSamplesIn || nSamplesIn < 0 ) {
            silk_assert( 0 );
            RESTORE_STACK;
            return SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES;
        }
        /* Make sure no more than one packet can be produced */
        if( 1000 * (opus_int32)nSamplesIn > encControl->payloadSize_ms * encControl->API_sampleRate ) {
            silk_assert( 0 );
            RESTORE_STACK;
            return SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES;
        }
    }

    TargetRate_bps = silk_RSHIFT32( encControl->bitRate, encControl->nChannelsInternal - 1 );
    for( n = 0; n < encControl->nChannelsInternal; n++ ) {
        /* Force the side channel to the same rate as the mid */
        opus_int force_fs_kHz = (n==1) ? psEnc->state_Fxx[0].sCmn.fs_kHz : 0;
        if( ( ret = silk_control_encoder( &psEnc->state_Fxx[ n ], encControl, TargetRate_bps, psEnc->allowBandwidthSwitch, n, force_fs_kHz ) ) != 0 ) {
            silk_assert( 0 );
            RESTORE_STACK;
            return ret;
        }
        if( psEnc->state_Fxx[n].sCmn.first_frame_after_reset || transition ) {
            for( i = 0; i < psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket; i++ ) {
                psEnc->state_Fxx[ n ].sCmn.LBRR_flags[ i ] = 0;
            }
        }
        psEnc->state_Fxx[ n ].sCmn.inDTX = psEnc->state_Fxx[ n ].sCmn.useDTX;
    }
    silk_assert( encControl->nChannelsInternal == 1 || psEnc->state_Fxx[ 0 ].sCmn.fs_kHz == psEnc->state_Fxx[ 1 ].sCmn.fs_kHz );

    /* Input buffering/resampling and encoding */
    nSamplesToBufferMax =
        10 * nBlocksOf10ms * psEnc->state_Fxx[ 0 ].sCmn.fs_kHz;
    nSamplesFromInputMax =
        silk_DIV32_16( nSamplesToBufferMax *
                           psEnc->state_Fxx[ 0 ].sCmn.API_fs_Hz,
                       psEnc->state_Fxx[ 0 ].sCmn.fs_kHz * 1000 );
    ALLOC( buf, nSamplesFromInputMax, opus_int16 );
    while( 1 ) {
        nSamplesToBuffer  = psEnc->state_Fxx[ 0 ].sCmn.frame_length - psEnc->state_Fxx[ 0 ].sCmn.inputBufIx;
        nSamplesToBuffer  = silk_min( nSamplesToBuffer, nSamplesToBufferMax );
        nSamplesFromInput = silk_DIV32_16( nSamplesToBuffer * psEnc->state_Fxx[ 0 ].sCmn.API_fs_Hz, psEnc->state_Fxx[ 0 ].sCmn.fs_kHz * 1000 );
        /* Resample and write to buffer */
        if( encControl->nChannelsAPI == 2 && encControl->nChannelsInternal == 2 ) {
            opus_int id = psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded;
            for( n = 0; n < nSamplesFromInput; n++ ) {
                buf[ n ] = samplesIn[ 2 * n ];
            }
            /* Making sure to start both resamplers from the same state when switching from mono to stereo */
            if( psEnc->nPrevChannelsInternal == 1 && id==0 ) {
               silk_memcpy( &psEnc->state_Fxx[ 1 ].sCmn.resampler_state, &psEnc->state_Fxx[ 0 ].sCmn.resampler_state, sizeof(psEnc->state_Fxx[ 1 ].sCmn.resampler_state));
            }

            ret += silk_resampler( &psEnc->state_Fxx[ 0 ].sCmn.resampler_state,
                &psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ psEnc->state_Fxx[ 0 ].sCmn.inputBufIx + 2 ], buf, nSamplesFromInput );
            psEnc->state_Fxx[ 0 ].sCmn.inputBufIx += nSamplesToBuffer;

            nSamplesToBuffer  = psEnc->state_Fxx[ 1 ].sCmn.frame_length - psEnc->state_Fxx[ 1 ].sCmn.inputBufIx;
            nSamplesToBuffer  = silk_min( nSamplesToBuffer, 10 * nBlocksOf10ms * psEnc->state_Fxx[ 1 ].sCmn.fs_kHz );
            for( n = 0; n < nSamplesFromInput; n++ ) {
                buf[ n ] = samplesIn[ 2 * n + 1 ];
            }
            ret += silk_resampler( &psEnc->state_Fxx[ 1 ].sCmn.resampler_state,
                &psEnc->state_Fxx[ 1 ].sCmn.inputBuf[ psEnc->state_Fxx[ 1 ].sCmn.inputBufIx + 2 ], buf, nSamplesFromInput );

            psEnc->state_Fxx[ 1 ].sCmn.inputBufIx += nSamplesToBuffer;
        } else if( encControl->nChannelsAPI == 2 && encControl->nChannelsInternal == 1 ) {
            /* Combine left and right channels before resampling */
            for( n = 0; n < nSamplesFromInput; n++ ) {
                sum = samplesIn[ 2 * n ] + samplesIn[ 2 * n + 1 ];
                buf[ n ] = (opus_int16)silk_RSHIFT_ROUND( sum,  1 );
            }
            ret += silk_resampler( &psEnc->state_Fxx[ 0 ].sCmn.resampler_state,
                &psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ psEnc->state_Fxx[ 0 ].sCmn.inputBufIx + 2 ], buf, nSamplesFromInput );
            /* On the first mono frame, average the results for the two resampler states  */
            if( psEnc->nPrevChannelsInternal == 2 && psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded == 0 ) {
               ret += silk_resampler( &psEnc->state_Fxx[ 1 ].sCmn.resampler_state,
                   &psEnc->state_Fxx[ 1 ].sCmn.inputBuf[ psEnc->state_Fxx[ 1 ].sCmn.inputBufIx + 2 ], buf, nSamplesFromInput );
               for( n = 0; n < psEnc->state_Fxx[ 0 ].sCmn.frame_length; n++ ) {
                  psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ psEnc->state_Fxx[ 0 ].sCmn.inputBufIx+n+2 ] =
                        silk_RSHIFT(psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ psEnc->state_Fxx[ 0 ].sCmn.inputBufIx+n+2 ]
                                  + psEnc->state_Fxx[ 1 ].sCmn.inputBuf[ psEnc->state_Fxx[ 1 ].sCmn.inputBufIx+n+2 ], 1);
               }
            }
            psEnc->state_Fxx[ 0 ].sCmn.inputBufIx += nSamplesToBuffer;
        } else {
            silk_assert( encControl->nChannelsAPI == 1 && encControl->nChannelsInternal == 1 );
            silk_memcpy(buf, samplesIn, nSamplesFromInput*sizeof(opus_int16));
            ret += silk_resampler( &psEnc->state_Fxx[ 0 ].sCmn.resampler_state,
                &psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ psEnc->state_Fxx[ 0 ].sCmn.inputBufIx + 2 ], buf, nSamplesFromInput );
            psEnc->state_Fxx[ 0 ].sCmn.inputBufIx += nSamplesToBuffer;
        }

        samplesIn  += nSamplesFromInput * encControl->nChannelsAPI;
        nSamplesIn -= nSamplesFromInput;

        /* Default */
        psEnc->allowBandwidthSwitch = 0;

        /* Silk encoder */
        if( psEnc->state_Fxx[ 0 ].sCmn.inputBufIx >= psEnc->state_Fxx[ 0 ].sCmn.frame_length ) {
            /* Enough data in input buffer, so encode */
            silk_assert( psEnc->state_Fxx[ 0 ].sCmn.inputBufIx == psEnc->state_Fxx[ 0 ].sCmn.frame_length );
            silk_assert( encControl->nChannelsInternal == 1 || psEnc->state_Fxx[ 1 ].sCmn.inputBufIx == psEnc->state_Fxx[ 1 ].sCmn.frame_length );

            /* Deal with LBRR data */
            if( psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded == 0 && !prefillFlag ) {
                /* Create space at start of payload for VAD and FEC flags */
                opus_uint8 iCDF[ 2 ] = { 0, 0 };
                iCDF[ 0 ] = 256 - silk_RSHIFT( 256, ( psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket + 1 ) * encControl->nChannelsInternal );
                ec_enc_icdf( psRangeEnc, 0, iCDF, 8 );

                /* Encode any LBRR data from previous packet */
                /* Encode LBRR flags */
                for( n = 0; n < encControl->nChannelsInternal; n++ ) {
                    LBRR_symbol = 0;
                    for( i = 0; i < psEnc->state_Fxx[ n ].sCmn.nFramesPerPacket; i++ ) {
                        LBRR_symbol |= silk_LSHIFT( psEnc->state_Fxx[ n ].sCmn.LBRR_flags[ i ], i );
                    }
                    psEnc->state_Fxx[ n ].sCmn.LBRR_flag = LBRR_symbol > 0 ? 1 : 0;
                    if( LBRR_symbol && psEnc->state_Fxx[ n ].sCmn.nFramesPerPacket > 1 ) {
                        ec_enc_icdf( psRangeEnc, LBRR_symbol - 1, silk_LBRR_flags_iCDF_ptr[ psEnc->state_Fxx[ n ].sCmn.nFramesPerPacket - 2 ], 8 );
                    }
                }

                /* Code LBRR indices and excitation signals */
                for( i = 0; i < psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket; i++ ) {
                    for( n = 0; n < encControl->nChannelsInternal; n++ ) {
                        if( psEnc->state_Fxx[ n ].sCmn.LBRR_flags[ i ] ) {
                            opus_int condCoding;

                            if( encControl->nChannelsInternal == 2 && n == 0 ) {
                                silk_stereo_encode_pred( psRangeEnc, psEnc->sStereo.predIx[ i ] );
                                /* For LBRR data there's no need to code the mid-only flag if the side-channel LBRR flag is set */
                                if( psEnc->state_Fxx[ 1 ].sCmn.LBRR_flags[ i ] == 0 ) {
                                    silk_stereo_encode_mid_only( psRangeEnc, psEnc->sStereo.mid_only_flags[ i ] );
                                }
                            }
                            /* Use conditional coding if previous frame available */
                            if( i > 0 && psEnc->state_Fxx[ n ].sCmn.LBRR_flags[ i - 1 ] ) {
                                condCoding = CODE_CONDITIONALLY;
                            } else {
                                condCoding = CODE_INDEPENDENTLY;
                            }
                            silk_encode_indices( &psEnc->state_Fxx[ n ].sCmn, psRangeEnc, i, 1, condCoding );
                            silk_encode_pulses( psRangeEnc, psEnc->state_Fxx[ n ].sCmn.indices_LBRR[i].signalType, psEnc->state_Fxx[ n ].sCmn.indices_LBRR[i].quantOffsetType,
                                psEnc->state_Fxx[ n ].sCmn.pulses_LBRR[ i ], psEnc->state_Fxx[ n ].sCmn.frame_length );
                        }
                    }
                }

                /* Reset LBRR flags */
                for( n = 0; n < encControl->nChannelsInternal; n++ ) {
                    silk_memset( psEnc->state_Fxx[ n ].sCmn.LBRR_flags, 0, sizeof( psEnc->state_Fxx[ n ].sCmn.LBRR_flags ) );
                }

                psEnc->nBitsUsedLBRR = ec_tell( psRangeEnc );
            }

            silk_HP_variable_cutoff( psEnc->state_Fxx );

            /* Total target bits for packet */
            nBits = silk_DIV32_16( silk_MUL( encControl->bitRate, encControl->payloadSize_ms ), 1000 );
            /* Subtract bits used for LBRR */
            if( !prefillFlag ) {
                nBits -= psEnc->nBitsUsedLBRR;
            }
            /* Divide by number of uncoded frames left in packet */
            nBits = silk_DIV32_16( nBits, psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket );
            /* Convert to bits/second */
            if( encControl->payloadSize_ms == 10 ) {
                TargetRate_bps = silk_SMULBB( nBits, 100 );
            } else {
                TargetRate_bps = silk_SMULBB( nBits, 50 );
            }
            /* Subtract fraction of bits in excess of target in previous frames and packets */
            TargetRate_bps -= silk_DIV32_16( silk_MUL( psEnc->nBitsExceeded, 1000 ), BITRESERVOIR_DECAY_TIME_MS );
            if( !prefillFlag && psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded > 0 ) {
                /* Compare actual vs target bits so far in this packet */
                opus_int32 bitsBalance = ec_tell( psRangeEnc ) - psEnc->nBitsUsedLBRR - nBits * psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded;
                TargetRate_bps -= silk_DIV32_16( silk_MUL( bitsBalance, 1000 ), BITRESERVOIR_DECAY_TIME_MS );
            }
            /* Never exceed input bitrate */
            TargetRate_bps = silk_LIMIT( TargetRate_bps, encControl->bitRate, 5000 );

            /* Convert Left/Right to Mid/Side */
            if( encControl->nChannelsInternal == 2 ) {
                silk_stereo_LR_to_MS( &psEnc->sStereo, &psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ 2 ], &psEnc->state_Fxx[ 1 ].sCmn.inputBuf[ 2 ],
                    psEnc->sStereo.predIx[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded ], &psEnc->sStereo.mid_only_flags[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded ],
                    MStargetRates_bps, TargetRate_bps, psEnc->state_Fxx[ 0 ].sCmn.speech_activity_Q8, encControl->toMono,
                    psEnc->state_Fxx[ 0 ].sCmn.fs_kHz, psEnc->state_Fxx[ 0 ].sCmn.frame_length );
                if( psEnc->sStereo.mid_only_flags[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded ] == 0 ) {
                    /* Reset side channel encoder memory for first frame with side coding */
                    if( psEnc->prev_decode_only_middle == 1 ) {
                        silk_memset( &psEnc->state_Fxx[ 1 ].sShape,               0, sizeof( psEnc->state_Fxx[ 1 ].sShape ) );
                        silk_memset( &psEnc->state_Fxx[ 1 ].sPrefilt,             0, sizeof( psEnc->state_Fxx[ 1 ].sPrefilt ) );
                        silk_memset( &psEnc->state_Fxx[ 1 ].sCmn.sNSQ,            0, sizeof( psEnc->state_Fxx[ 1 ].sCmn.sNSQ ) );
                        silk_memset( psEnc->state_Fxx[ 1 ].sCmn.prev_NLSFq_Q15,   0, sizeof( psEnc->state_Fxx[ 1 ].sCmn.prev_NLSFq_Q15 ) );
                        silk_memset( &psEnc->state_Fxx[ 1 ].sCmn.sLP.In_LP_State, 0, sizeof( psEnc->state_Fxx[ 1 ].sCmn.sLP.In_LP_State ) );
                        psEnc->state_Fxx[ 1 ].sCmn.prevLag                 = 100;
                        psEnc->state_Fxx[ 1 ].sCmn.sNSQ.lagPrev            = 100;
                        psEnc->state_Fxx[ 1 ].sShape.LastGainIndex         = 10;
                        psEnc->state_Fxx[ 1 ].sCmn.prevSignalType          = TYPE_NO_VOICE_ACTIVITY;
                        psEnc->state_Fxx[ 1 ].sCmn.sNSQ.prev_gain_Q16      = 65536;
                        psEnc->state_Fxx[ 1 ].sCmn.first_frame_after_reset = 1;
                    }
                    silk_encode_do_VAD_Fxx( &psEnc->state_Fxx[ 1 ] );
                } else {
                    psEnc->state_Fxx[ 1 ].sCmn.VAD_flags[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded ] = 0;
                }
                if( !prefillFlag ) {
                    silk_stereo_encode_pred( psRangeEnc, psEnc->sStereo.predIx[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded ] );
                    if( psEnc->state_Fxx[ 1 ].sCmn.VAD_flags[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded ] == 0 ) {
                        silk_stereo_encode_mid_only( psRangeEnc, psEnc->sStereo.mid_only_flags[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded ] );
                    }
                }
            } else {
                /* Buffering */
                silk_memcpy( psEnc->state_Fxx[ 0 ].sCmn.inputBuf, psEnc->sStereo.sMid, 2 * sizeof( opus_int16 ) );
                silk_memcpy( psEnc->sStereo.sMid, &psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ psEnc->state_Fxx[ 0 ].sCmn.frame_length ], 2 * sizeof( opus_int16 ) );
            }
            silk_encode_do_VAD_Fxx( &psEnc->state_Fxx[ 0 ] );

            /* Encode */
            for( n = 0; n < encControl->nChannelsInternal; n++ ) {
                opus_int maxBits, useCBR;

                /* Handling rate constraints */
                maxBits = encControl->maxBits;
                if( tot_blocks == 2 && curr_block == 0 ) {
                    maxBits = maxBits * 3 / 5;
                } else if( tot_blocks == 3 ) {
                    if( curr_block == 0 ) {
                        maxBits = maxBits * 2 / 5;
                    } else if( curr_block == 1 ) {
                        maxBits = maxBits * 3 / 4;
                    }
                }
                useCBR = encControl->useCBR && curr_block == tot_blocks - 1;

                if( encControl->nChannelsInternal == 1 ) {
                    channelRate_bps = TargetRate_bps;
                } else {
                    channelRate_bps = MStargetRates_bps[ n ];
                    if( n == 0 && MStargetRates_bps[ 1 ] > 0 ) {
                        useCBR = 0;
                        /* Give mid up to 1/2 of the max bits for that frame */
                        maxBits -= encControl->maxBits / ( tot_blocks * 2 );
                    }
                }

                if( channelRate_bps > 0 ) {
                    opus_int condCoding;

                    silk_control_SNR( &psEnc->state_Fxx[ n ].sCmn, channelRate_bps );

                    /* Use independent coding if no previous frame available */
                    if( psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded - n <= 0 ) {
                        condCoding = CODE_INDEPENDENTLY;
                    } else if( n > 0 && psEnc->prev_decode_only_middle ) {
                        /* If we skipped a side frame in this packet, we don't
                           need LTP scaling; the LTP state is well-defined. */
                        condCoding = CODE_INDEPENDENTLY_NO_LTP_SCALING;
                    } else {
                        condCoding = CODE_CONDITIONALLY;
                    }
                    if( ( ret = silk_encode_frame_Fxx( &psEnc->state_Fxx[ n ], nBytesOut, psRangeEnc, condCoding, maxBits, useCBR ) ) != 0 ) {
                        silk_assert( 0 );
                    }
                }
                psEnc->state_Fxx[ n ].sCmn.controlled_since_last_payload = 0;
                psEnc->state_Fxx[ n ].sCmn.inputBufIx = 0;
                psEnc->state_Fxx[ n ].sCmn.nFramesEncoded++;
            }
            psEnc->prev_decode_only_middle = psEnc->sStereo.mid_only_flags[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded - 1 ];

            /* Insert VAD and FEC flags at beginning of bitstream */
            if( *nBytesOut > 0 && psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded == psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket) {
                flags = 0;
                for( n = 0; n < encControl->nChannelsInternal; n++ ) {
                    for( i = 0; i < psEnc->state_Fxx[ n ].sCmn.nFramesPerPacket; i++ ) {
                        flags  = silk_LSHIFT( flags, 1 );
                        flags |= psEnc->state_Fxx[ n ].sCmn.VAD_flags[ i ];
                    }
                    flags  = silk_LSHIFT( flags, 1 );
                    flags |= psEnc->state_Fxx[ n ].sCmn.LBRR_flag;
                }
                if( !prefillFlag ) {
                    ec_enc_patch_initial_bits( psRangeEnc, flags, ( psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket + 1 ) * encControl->nChannelsInternal );
                }

                /* Return zero bytes if all channels DTXed */
                if( psEnc->state_Fxx[ 0 ].sCmn.inDTX && ( encControl->nChannelsInternal == 1 || psEnc->state_Fxx[ 1 ].sCmn.inDTX ) ) {
                    *nBytesOut = 0;
                }

                psEnc->nBitsExceeded += *nBytesOut * 8;
                psEnc->nBitsExceeded -= silk_DIV32_16( silk_MUL( encControl->bitRate, encControl->payloadSize_ms ), 1000 );
                psEnc->nBitsExceeded  = silk_LIMIT( psEnc->nBitsExceeded, 0, 10000 );

                /* Update flag indicating if bandwidth switching is allowed */
                speech_act_thr_for_switch_Q8 = (opus_int) silk_SMLAWB( SILK_FIX_CONST( SPEECH_ACTIVITY_DTX_THRES, 8 ),
                    SILK_FIX_CONST( ( 1 - SPEECH_ACTIVITY_DTX_THRES ) / MAX_BANDWIDTH_SWITCH_DELAY_MS, 16 + 8 ), psEnc->timeSinceSwitchAllowed_ms );
                if( psEnc->state_Fxx[ 0 ].sCmn.speech_activity_Q8 < speech_act_thr_for_switch_Q8 ) {
                    psEnc->allowBandwidthSwitch = 1;
                    psEnc->timeSinceSwitchAllowed_ms = 0;
                } else {
                    psEnc->allowBandwidthSwitch = 0;
                    psEnc->timeSinceSwitchAllowed_ms += encControl->payloadSize_ms;
                }
            }

            if( nSamplesIn == 0 ) {
                break;
            }
        } else {
            break;
        }
        curr_block++;
    }

    psEnc->nPrevChannelsInternal = encControl->nChannelsInternal;

    encControl->allowBandwidthSwitch = psEnc->allowBandwidthSwitch;
    encControl->inWBmodeWithoutVariableLP = psEnc->state_Fxx[ 0 ].sCmn.fs_kHz == 16 && psEnc->state_Fxx[ 0 ].sCmn.sLP.mode == 0;
    encControl->internalSampleRate = silk_SMULBB( psEnc->state_Fxx[ 0 ].sCmn.fs_kHz, 1000 );
    encControl->stereoWidth_Q14 = encControl->toMono ? 0 : psEnc->sStereo.smth_width_Q14;
    if( prefillFlag ) {
        encControl->payloadSize_ms = tmp_payloadSize_ms;
        encControl->complexity = tmp_complexity;
        for( n = 0; n < encControl->nChannelsInternal; n++ ) {
            psEnc->state_Fxx[ n ].sCmn.controlled_since_last_payload = 0;
            psEnc->state_Fxx[ n ].sCmn.prefillFlag = 0;
        }
    }

    RESTORE_STACK;
    return ret;
}
Exemple #19
0
void silk_prefilter_FIX(
    silk_encoder_state_FIX          *psEnc,                                 /* I/O  Encoder state                                                               */
    const silk_encoder_control_FIX  *psEncCtrl,                             /* I    Encoder control                                                             */
    opus_int32                      xw_Q3[],                                /* O    Weighted signal                                                             */
    const opus_int16                x[]                                     /* I    Speech signal                                                               */
)
{
    silk_prefilter_state_FIX *P = &psEnc->sPrefilt;
    opus_int   j, k, lag;
    opus_int32 tmp_32;
    const opus_int16 *AR1_shp_Q13;
    const opus_int16 *px;
    opus_int32 *pxw_Q3;
    opus_int   HarmShapeGain_Q12, Tilt_Q14;
    opus_int32 HarmShapeFIRPacked_Q12, LF_shp_Q14;
    VARDECL( opus_int32, x_filt_Q12 );
    VARDECL( opus_int32, st_res_Q2 );
    opus_int16 B_Q10[ 2 ];
    SAVE_STACK;

    /* Set up pointers */
    px  = x;
    pxw_Q3 = xw_Q3;
    lag = P->lagPrev;
    ALLOC( x_filt_Q12, psEnc->sCmn.subfr_length, opus_int32 );
    ALLOC( st_res_Q2, psEnc->sCmn.subfr_length, opus_int32 );
    for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
        /* Update Variables that change per sub frame */
        if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
            lag = psEncCtrl->pitchL[ k ];
        }

        /* Noise shape parameters */
        HarmShapeGain_Q12 = silk_SMULWB( (opus_int32)psEncCtrl->HarmShapeGain_Q14[ k ], 16384 - psEncCtrl->HarmBoost_Q14[ k ] );
        silk_assert( HarmShapeGain_Q12 >= 0 );
        HarmShapeFIRPacked_Q12  =                          silk_RSHIFT( HarmShapeGain_Q12, 2 );
        HarmShapeFIRPacked_Q12 |= silk_LSHIFT( (opus_int32)silk_RSHIFT( HarmShapeGain_Q12, 1 ), 16 );
        Tilt_Q14    = psEncCtrl->Tilt_Q14[   k ];
        LF_shp_Q14  = psEncCtrl->LF_shp_Q14[ k ];
        AR1_shp_Q13 = &psEncCtrl->AR1_Q13[   k * MAX_SHAPE_LPC_ORDER ];

        /* Short term FIR filtering*/
        silk_warped_LPC_analysis_filter_FIX( P->sAR_shp, st_res_Q2, AR1_shp_Q13, px,
            psEnc->sCmn.warping_Q16, psEnc->sCmn.subfr_length, psEnc->sCmn.shapingLPCOrder );

        /* Reduce (mainly) low frequencies during harmonic emphasis */
        B_Q10[ 0 ] = silk_RSHIFT_ROUND( psEncCtrl->GainsPre_Q14[ k ], 4 );
        tmp_32 = silk_SMLABB( SILK_FIX_CONST( INPUT_TILT, 26 ), psEncCtrl->HarmBoost_Q14[ k ], HarmShapeGain_Q12 );   /* Q26 */
        tmp_32 = silk_SMLABB( tmp_32, psEncCtrl->coding_quality_Q14, SILK_FIX_CONST( HIGH_RATE_INPUT_TILT, 12 ) );    /* Q26 */
        tmp_32 = silk_SMULWB( tmp_32, -psEncCtrl->GainsPre_Q14[ k ] );                                                /* Q24 */
        tmp_32 = silk_RSHIFT_ROUND( tmp_32, 14 );                                                                     /* Q10 */
        B_Q10[ 1 ]= silk_SAT16( tmp_32 );
        x_filt_Q12[ 0 ] = silk_MLA( silk_MUL( st_res_Q2[ 0 ], B_Q10[ 0 ] ), P->sHarmHP_Q2, B_Q10[ 1 ] );
        for( j = 1; j < psEnc->sCmn.subfr_length; j++ ) {
            x_filt_Q12[ j ] = silk_MLA( silk_MUL( st_res_Q2[ j ], B_Q10[ 0 ] ), st_res_Q2[ j - 1 ], B_Q10[ 1 ] );
        }
        P->sHarmHP_Q2 = st_res_Q2[ psEnc->sCmn.subfr_length - 1 ];

        silk_prefilt_FIX( P, x_filt_Q12, pxw_Q3, HarmShapeFIRPacked_Q12, Tilt_Q14, LF_shp_Q14, lag, psEnc->sCmn.subfr_length );

        px  += psEnc->sCmn.subfr_length;
        pxw_Q3 += psEnc->sCmn.subfr_length;
    }

    P->lagPrev = psEncCtrl->pitchL[ psEnc->sCmn.nb_subfr - 1 ];
    RESTORE_STACK;
}
void silk_find_LTP_FIX(
    opus_int16                      b_Q14[ MAX_NB_SUBFR * LTP_ORDER ],      /* O    LTP coefs                                                                   */
    opus_int32                      WLTP[ MAX_NB_SUBFR * LTP_ORDER * LTP_ORDER ], /* O    Weight for LTP quantization                                           */
    opus_int                        *LTPredCodGain_Q7,                      /* O    LTP coding gain                                                             */
    const opus_int16                r_lpc[],                                /* I    residual signal after LPC signal + state for first 10 ms                    */
    const opus_int                  lag[ MAX_NB_SUBFR ],                    /* I    LTP lags                                                                    */
    const opus_int32                Wght_Q15[ MAX_NB_SUBFR ],               /* I    weights                                                                     */
    const opus_int                  subfr_length,                           /* I    subframe length                                                             */
    const opus_int                  nb_subfr,                               /* I    number of subframes                                                         */
    const opus_int                  mem_offset,                             /* I    number of samples in LTP memory                                             */
    opus_int                        corr_rshifts[ MAX_NB_SUBFR ]            /* O    right shifts applied to correlations                                        */
)
{
    opus_int   i, k, lshift;
    const opus_int16 *r_ptr, *lag_ptr;
    opus_int16 *b_Q14_ptr;

    opus_int32 regu;
    opus_int32 *WLTP_ptr;
    opus_int32 b_Q16[ LTP_ORDER ], delta_b_Q14[ LTP_ORDER ], d_Q14[ MAX_NB_SUBFR ], nrg[ MAX_NB_SUBFR ], g_Q26;
    opus_int32 w[ MAX_NB_SUBFR ], WLTP_max, max_abs_d_Q14, max_w_bits;

    opus_int32 temp32, denom32;
    opus_int   extra_shifts;
    opus_int   rr_shifts, maxRshifts, maxRshifts_wxtra, LZs;
    opus_int32 LPC_res_nrg, LPC_LTP_res_nrg, div_Q16;
    opus_int32 Rr[ LTP_ORDER ], rr[ MAX_NB_SUBFR ];
    opus_int32 wd, m_Q12;

    b_Q14_ptr = b_Q14;
    WLTP_ptr  = WLTP;
    r_ptr     = &r_lpc[ mem_offset ];
    for( k = 0; k < nb_subfr; k++ ) {
        lag_ptr = r_ptr - ( lag[ k ] + LTP_ORDER / 2 );

        silk_sum_sqr_shift( &rr[ k ], &rr_shifts, r_ptr, subfr_length ); /* rr[ k ] in Q( -rr_shifts ) */

        /* Assure headroom */
        LZs = silk_CLZ32( rr[k] );
        if( LZs < LTP_CORRS_HEAD_ROOM ) {
            rr[ k ] = silk_RSHIFT_ROUND( rr[ k ], LTP_CORRS_HEAD_ROOM - LZs );
            rr_shifts += ( LTP_CORRS_HEAD_ROOM - LZs );
        }
        corr_rshifts[ k ] = rr_shifts;
        silk_corrMatrix_FIX( lag_ptr, subfr_length, LTP_ORDER, LTP_CORRS_HEAD_ROOM, WLTP_ptr, &corr_rshifts[ k ] );  /* WLTP_fix_ptr in Q( -corr_rshifts[ k ] ) */

        /* The correlation vector always has lower max abs value than rr and/or RR so head room is assured */
        silk_corrVector_FIX( lag_ptr, r_ptr, subfr_length, LTP_ORDER, Rr, corr_rshifts[ k ] );  /* Rr_fix_ptr   in Q( -corr_rshifts[ k ] ) */
        if( corr_rshifts[ k ] > rr_shifts ) {
            rr[ k ] = silk_RSHIFT( rr[ k ], corr_rshifts[ k ] - rr_shifts ); /* rr[ k ] in Q( -corr_rshifts[ k ] ) */
        }
        silk_assert( rr[ k ] >= 0 );

        regu = 1;
        regu = silk_SMLAWB( regu, rr[ k ], SILK_FIX_CONST( LTP_DAMPING/3, 16 ) );
        regu = silk_SMLAWB( regu, matrix_ptr( WLTP_ptr, 0, 0, LTP_ORDER ), SILK_FIX_CONST( LTP_DAMPING/3, 16 ) );
        regu = silk_SMLAWB( regu, matrix_ptr( WLTP_ptr, LTP_ORDER-1, LTP_ORDER-1, LTP_ORDER ), SILK_FIX_CONST( LTP_DAMPING/3, 16 ) );
        silk_regularize_correlations_FIX( WLTP_ptr, &rr[k], regu, LTP_ORDER );

        silk_solve_LDL_FIX( WLTP_ptr, LTP_ORDER, Rr, b_Q16 ); /* WLTP_fix_ptr and Rr_fix_ptr both in Q(-corr_rshifts[k]) */

        /* Limit and store in Q14 */
        silk_fit_LTP( b_Q16, b_Q14_ptr );

        /* Calculate residual energy */
        nrg[ k ] = silk_residual_energy16_covar_FIX( b_Q14_ptr, WLTP_ptr, Rr, rr[ k ], LTP_ORDER, 14 ); /* nrg_fix in Q( -corr_rshifts[ k ] ) */

        /* temp = Wght[ k ] / ( nrg[ k ] * Wght[ k ] + 0.01f * subfr_length ); */
        extra_shifts = silk_min_int( corr_rshifts[ k ], LTP_CORRS_HEAD_ROOM );
        denom32 = silk_LSHIFT_SAT32( silk_SMULWB( nrg[ k ], Wght_Q15[ k ] ), 1 + extra_shifts ) + /* Q( -corr_rshifts[ k ] + extra_shifts ) */
            silk_RSHIFT( silk_SMULWB( subfr_length, 655 ), corr_rshifts[ k ] - extra_shifts );    /* Q( -corr_rshifts[ k ] + extra_shifts ) */
        denom32 = silk_max( denom32, 1 );
        silk_assert( ((opus_int64)Wght_Q15[ k ] << 16 ) < silk_int32_MAX );                       /* Wght always < 0.5 in Q0 */
        temp32 = silk_DIV32( silk_LSHIFT( (opus_int32)Wght_Q15[ k ], 16 ), denom32 );             /* Q( 15 + 16 + corr_rshifts[k] - extra_shifts ) */
        temp32 = silk_RSHIFT( temp32, 31 + corr_rshifts[ k ] - extra_shifts - 26 );               /* Q26 */

        /* Limit temp such that the below scaling never wraps around */
        WLTP_max = 0;
        for( i = 0; i < LTP_ORDER * LTP_ORDER; i++ ) {
            WLTP_max = silk_max( WLTP_ptr[ i ], WLTP_max );
        }
        lshift = silk_CLZ32( WLTP_max ) - 1 - 3; /* keep 3 bits free for vq_nearest_neighbor_fix */
        silk_assert( 26 - 18 + lshift >= 0 );
        if( 26 - 18 + lshift < 31 ) {
            temp32 = silk_min_32( temp32, silk_LSHIFT( (opus_int32)1, 26 - 18 + lshift ) );
        }

        silk_scale_vector32_Q26_lshift_18( WLTP_ptr, temp32, LTP_ORDER * LTP_ORDER ); /* WLTP_ptr in Q( 18 - corr_rshifts[ k ] ) */

        w[ k ] = matrix_ptr( WLTP_ptr, LTP_ORDER/2, LTP_ORDER/2, LTP_ORDER ); /* w in Q( 18 - corr_rshifts[ k ] ) */
        silk_assert( w[k] >= 0 );

        r_ptr     += subfr_length;
        b_Q14_ptr += LTP_ORDER;
        WLTP_ptr  += LTP_ORDER * LTP_ORDER;
    }

    maxRshifts = 0;
    for( k = 0; k < nb_subfr; k++ ) {
        maxRshifts = silk_max_int( corr_rshifts[ k ], maxRshifts );
    }

    /* Compute LTP coding gain */
    if( LTPredCodGain_Q7 != NULL ) {
        LPC_LTP_res_nrg = 0;
        LPC_res_nrg     = 0;
        silk_assert( LTP_CORRS_HEAD_ROOM >= 2 ); /* Check that no overflow will happen when adding */
        for( k = 0; k < nb_subfr; k++ ) {
            LPC_res_nrg     = silk_ADD32( LPC_res_nrg,     silk_RSHIFT( silk_ADD32( silk_SMULWB(  rr[ k ], Wght_Q15[ k ] ), 1 ), 1 + ( maxRshifts - corr_rshifts[ k ] ) ) ); /* Q( -maxRshifts ) */
            LPC_LTP_res_nrg = silk_ADD32( LPC_LTP_res_nrg, silk_RSHIFT( silk_ADD32( silk_SMULWB( nrg[ k ], Wght_Q15[ k ] ), 1 ), 1 + ( maxRshifts - corr_rshifts[ k ] ) ) ); /* Q( -maxRshifts ) */
        }
        LPC_LTP_res_nrg = silk_max( LPC_LTP_res_nrg, 1 ); /* avoid division by zero */

        div_Q16 = silk_DIV32_varQ( LPC_res_nrg, LPC_LTP_res_nrg, 16 );
        *LTPredCodGain_Q7 = ( opus_int )silk_SMULBB( 3, silk_lin2log( div_Q16 ) - ( 16 << 7 ) );

        silk_assert( *LTPredCodGain_Q7 == ( opus_int )silk_SAT16( silk_MUL( 3, silk_lin2log( div_Q16 ) - ( 16 << 7 ) ) ) );
    }

    /* smoothing */
    /* d = sum( B, 1 ); */
    b_Q14_ptr = b_Q14;
    for( k = 0; k < nb_subfr; k++ ) {
        d_Q14[ k ] = 0;
        for( i = 0; i < LTP_ORDER; i++ ) {
            d_Q14[ k ] += b_Q14_ptr[ i ];
        }
        b_Q14_ptr += LTP_ORDER;
    }

    /* m = ( w * d' ) / ( sum( w ) + 1e-3 ); */

    /* Find maximum absolute value of d_Q14 and the bits used by w in Q0 */
    max_abs_d_Q14 = 0;
    max_w_bits    = 0;
    for( k = 0; k < nb_subfr; k++ ) {
        max_abs_d_Q14 = silk_max_32( max_abs_d_Q14, silk_abs( d_Q14[ k ] ) );
        /* w[ k ] is in Q( 18 - corr_rshifts[ k ] ) */
        /* Find bits needed in Q( 18 - maxRshifts ) */
        max_w_bits = silk_max_32( max_w_bits, 32 - silk_CLZ32( w[ k ] ) + corr_rshifts[ k ] - maxRshifts );
    }

    /* max_abs_d_Q14 = (5 << 15); worst case, i.e. LTP_ORDER * -silk_int16_MIN */
    silk_assert( max_abs_d_Q14 <= ( 5 << 15 ) );

    /* How many bits is needed for w*d' in Q( 18 - maxRshifts ) in the worst case, of all d_Q14's being equal to max_abs_d_Q14 */
    extra_shifts = max_w_bits + 32 - silk_CLZ32( max_abs_d_Q14 ) - 14;

    /* Subtract what we got available; bits in output var plus maxRshifts */
    extra_shifts -= ( 32 - 1 - 2 + maxRshifts ); /* Keep sign bit free as well as 2 bits for accumulation */
    extra_shifts = silk_max_int( extra_shifts, 0 );

    maxRshifts_wxtra = maxRshifts + extra_shifts;

    temp32 = silk_RSHIFT( 262, maxRshifts + extra_shifts ) + 1; /* 1e-3f in Q( 18 - (maxRshifts + extra_shifts) ) */
    wd = 0;
    for( k = 0; k < nb_subfr; k++ ) {
        /* w has at least 2 bits of headroom so no overflow should happen */
        temp32 = silk_ADD32( temp32,                     silk_RSHIFT( w[ k ], maxRshifts_wxtra - corr_rshifts[ k ] ) );                      /* Q( 18 - maxRshifts_wxtra ) */
        wd     = silk_ADD32( wd, silk_LSHIFT( silk_SMULWW( silk_RSHIFT( w[ k ], maxRshifts_wxtra - corr_rshifts[ k ] ), d_Q14[ k ] ), 2 ) ); /* Q( 18 - maxRshifts_wxtra ) */
    }
    m_Q12 = silk_DIV32_varQ( wd, temp32, 12 );

    b_Q14_ptr = b_Q14;
    for( k = 0; k < nb_subfr; k++ ) {
        /* w_fix[ k ] from Q( 18 - corr_rshifts[ k ] ) to Q( 16 ) */
        if( 2 - corr_rshifts[k] > 0 ) {
            temp32 = silk_RSHIFT( w[ k ], 2 - corr_rshifts[ k ] );
        } else {
            temp32 = silk_LSHIFT_SAT32( w[ k ], corr_rshifts[ k ] - 2 );
        }

        g_Q26 = silk_MUL(
            silk_DIV32(
                SILK_FIX_CONST( LTP_SMOOTHING, 26 ),
                silk_RSHIFT( SILK_FIX_CONST( LTP_SMOOTHING, 26 ), 10 ) + temp32 ),                          /* Q10 */
            silk_LSHIFT_SAT32( silk_SUB_SAT32( (opus_int32)m_Q12, silk_RSHIFT( d_Q14[ k ], 2 ) ), 4 ) );    /* Q16 */

        temp32 = 0;
        for( i = 0; i < LTP_ORDER; i++ ) {
            delta_b_Q14[ i ] = silk_max_16( b_Q14_ptr[ i ], 1638 );     /* 1638_Q14 = 0.1_Q0 */
            temp32 += delta_b_Q14[ i ];                                 /* Q14 */
        }
        temp32 = silk_DIV32( g_Q26, temp32 );                           /* Q14 -> Q12 */
        for( i = 0; i < LTP_ORDER; i++ ) {
            b_Q14_ptr[ i ] = silk_LIMIT_32( (opus_int32)b_Q14_ptr[ i ] + silk_SMULWB( silk_LSHIFT_SAT32( temp32, 4 ), delta_b_Q14[ i ] ), -16000, 28000 );
        }
        b_Q14_ptr += LTP_ORDER;
    }
}
/* Compute reflection coefficients from input signal */
void silk_burg_modified(
    opus_int32                  *res_nrg,           /* O    Residual energy                                             */
    opus_int                    *res_nrg_Q,         /* O    Residual energy Q value                                     */
    opus_int32                  A_Q16[],            /* O    Prediction coefficients (length order)                      */
    const opus_int16            x[],                /* I    Input signal, length: nb_subfr * ( D + subfr_length )       */
    const opus_int32            minInvGain_Q30,     /* I    Inverse of max prediction gain                              */
    const opus_int              subfr_length,       /* I    Input signal subframe length (incl. D preceding samples)    */
    const opus_int              nb_subfr,           /* I    Number of subframes stacked in x                            */
    const opus_int              D                   /* I    Order                                                       */
)
{
    opus_int         k, n, s, lz, rshifts, rshifts_extra, reached_max_gain;
    opus_int32       C0, num, nrg, rc_Q31, invGain_Q30, Atmp_QA, Atmp1, tmp1, tmp2, x1, x2;
    const opus_int16 *x_ptr;
    opus_int32       C_first_row[ SILK_MAX_ORDER_LPC ];
    opus_int32       C_last_row[  SILK_MAX_ORDER_LPC ];
    opus_int32       Af_QA[       SILK_MAX_ORDER_LPC ];
    opus_int32       CAf[ SILK_MAX_ORDER_LPC + 1 ];
    opus_int32       CAb[ SILK_MAX_ORDER_LPC + 1 ];

    silk_assert( subfr_length * nb_subfr <= MAX_FRAME_SIZE );

    /* Compute autocorrelations, added over subframes */
    silk_sum_sqr_shift( &C0, &rshifts, x, nb_subfr * subfr_length );
    if( rshifts > MAX_RSHIFTS ) {
        C0 = silk_LSHIFT32( C0, rshifts - MAX_RSHIFTS );
        silk_assert( C0 > 0 );
        rshifts = MAX_RSHIFTS;
    } else {
        lz = silk_CLZ32( C0 ) - 1;
        rshifts_extra = N_BITS_HEAD_ROOM - lz;
        if( rshifts_extra > 0 ) {
            rshifts_extra = silk_min( rshifts_extra, MAX_RSHIFTS - rshifts );
            C0 = silk_RSHIFT32( C0, rshifts_extra );
        } else {
            rshifts_extra = silk_max( rshifts_extra, MIN_RSHIFTS - rshifts );
            C0 = silk_LSHIFT32( C0, -rshifts_extra );
        }
        rshifts += rshifts_extra;
    }
    CAb[ 0 ] = CAf[ 0 ] = C0 + silk_SMMUL( SILK_FIX_CONST( FIND_LPC_COND_FAC, 32 ), C0 ) + 1;                                /* Q(-rshifts) */
    silk_memset( C_first_row, 0, SILK_MAX_ORDER_LPC * sizeof( opus_int32 ) );
    if( rshifts > 0 ) {
        for( s = 0; s < nb_subfr; s++ ) {
            x_ptr = x + s * subfr_length;
            for( n = 1; n < D + 1; n++ ) {
                C_first_row[ n - 1 ] += (opus_int32)silk_RSHIFT64(
                    silk_inner_prod16_aligned_64( x_ptr, x_ptr + n, subfr_length - n ), rshifts );
            }
        }
    } else {
        for( s = 0; s < nb_subfr; s++ ) {
            x_ptr = x + s * subfr_length;
            for( n = 1; n < D + 1; n++ ) {
                C_first_row[ n - 1 ] += silk_LSHIFT32(
                    silk_inner_prod_aligned( x_ptr, x_ptr + n, subfr_length - n ), -rshifts );
            }
        }
    }
    silk_memcpy( C_last_row, C_first_row, SILK_MAX_ORDER_LPC * sizeof( opus_int32 ) );

    /* Initialize */
    CAb[ 0 ] = CAf[ 0 ] = C0 + silk_SMMUL( SILK_FIX_CONST( FIND_LPC_COND_FAC, 32 ), C0 ) + 1;                                /* Q(-rshifts) */

    invGain_Q30 = (opus_int32)1 << 30;
    reached_max_gain = 0;
    for( n = 0; n < D; n++ ) {
        /* Update first row of correlation matrix (without first element) */
        /* Update last row of correlation matrix (without last element, stored in reversed order) */
        /* Update C * Af */
        /* Update C * flipud(Af) (stored in reversed order) */
        if( rshifts > -2 ) {
            for( s = 0; s < nb_subfr; s++ ) {
                x_ptr = x + s * subfr_length;
                x1  = -silk_LSHIFT32( (opus_int32)x_ptr[ n ],                    16 - rshifts );        /* Q(16-rshifts) */
                x2  = -silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n - 1 ], 16 - rshifts );        /* Q(16-rshifts) */
                tmp1 = silk_LSHIFT32( (opus_int32)x_ptr[ n ],                    QA - 16 );             /* Q(QA-16) */
                tmp2 = silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n - 1 ], QA - 16 );             /* Q(QA-16) */
                for( k = 0; k < n; k++ ) {
                    C_first_row[ k ] = silk_SMLAWB( C_first_row[ k ], x1, x_ptr[ n - k - 1 ]            ); /* Q( -rshifts ) */
                    C_last_row[ k ]  = silk_SMLAWB( C_last_row[ k ],  x2, x_ptr[ subfr_length - n + k ] ); /* Q( -rshifts ) */
                    Atmp_QA = Af_QA[ k ];
                    tmp1 = silk_SMLAWB( tmp1, Atmp_QA, x_ptr[ n - k - 1 ]            );                 /* Q(QA-16) */
                    tmp2 = silk_SMLAWB( tmp2, Atmp_QA, x_ptr[ subfr_length - n + k ] );                 /* Q(QA-16) */
                }
                tmp1 = silk_LSHIFT32( -tmp1, 32 - QA - rshifts );                                       /* Q(16-rshifts) */
                tmp2 = silk_LSHIFT32( -tmp2, 32 - QA - rshifts );                                       /* Q(16-rshifts) */
                for( k = 0; k <= n; k++ ) {
                    CAf[ k ] = silk_SMLAWB( CAf[ k ], tmp1, x_ptr[ n - k ]                    );        /* Q( -rshift ) */
                    CAb[ k ] = silk_SMLAWB( CAb[ k ], tmp2, x_ptr[ subfr_length - n + k - 1 ] );        /* Q( -rshift ) */
                }
            }
        } else {
            for( s = 0; s < nb_subfr; s++ ) {
                x_ptr = x + s * subfr_length;
                x1  = -silk_LSHIFT32( (opus_int32)x_ptr[ n ],                    -rshifts );            /* Q( -rshifts ) */
                x2  = -silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n - 1 ], -rshifts );            /* Q( -rshifts ) */
                tmp1 = silk_LSHIFT32( (opus_int32)x_ptr[ n ],                    17 );                  /* Q17 */
                tmp2 = silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n - 1 ], 17 );                  /* Q17 */
                for( k = 0; k < n; k++ ) {
                    C_first_row[ k ] = silk_MLA( C_first_row[ k ], x1, x_ptr[ n - k - 1 ]            ); /* Q( -rshifts ) */
                    C_last_row[ k ]  = silk_MLA( C_last_row[ k ],  x2, x_ptr[ subfr_length - n + k ] ); /* Q( -rshifts ) */
                    Atmp1 = silk_RSHIFT_ROUND( Af_QA[ k ], QA - 17 );                                   /* Q17 */
                    tmp1 = silk_MLA( tmp1, x_ptr[ n - k - 1 ],            Atmp1 );                      /* Q17 */
                    tmp2 = silk_MLA( tmp2, x_ptr[ subfr_length - n + k ], Atmp1 );                      /* Q17 */
                }
                tmp1 = -tmp1;                                                                           /* Q17 */
                tmp2 = -tmp2;                                                                           /* Q17 */
                for( k = 0; k <= n; k++ ) {
                    CAf[ k ] = silk_SMLAWW( CAf[ k ], tmp1,
                        silk_LSHIFT32( (opus_int32)x_ptr[ n - k ], -rshifts - 1 ) );                    /* Q( -rshift ) */
                    CAb[ k ] = silk_SMLAWW( CAb[ k ], tmp2,
                        silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n + k - 1 ], -rshifts - 1 ) ); /* Q( -rshift ) */
                }
            }
        }

        /* Calculate nominator and denominator for the next order reflection (parcor) coefficient */
        tmp1 = C_first_row[ n ];                                                                        /* Q( -rshifts ) */
        tmp2 = C_last_row[ n ];                                                                         /* Q( -rshifts ) */
        num  = 0;                                                                                       /* Q( -rshifts ) */
        nrg  = silk_ADD32( CAb[ 0 ], CAf[ 0 ] );                                                        /* Q( 1-rshifts ) */
        for( k = 0; k < n; k++ ) {
            Atmp_QA = Af_QA[ k ];
            lz = silk_CLZ32( silk_abs( Atmp_QA ) ) - 1;
            lz = silk_min( 32 - QA, lz );
            Atmp1 = silk_LSHIFT32( Atmp_QA, lz );                                                       /* Q( QA + lz ) */

            tmp1 = silk_ADD_LSHIFT32( tmp1, silk_SMMUL( C_last_row[  n - k - 1 ], Atmp1 ), 32 - QA - lz );  /* Q( -rshifts ) */
            tmp2 = silk_ADD_LSHIFT32( tmp2, silk_SMMUL( C_first_row[ n - k - 1 ], Atmp1 ), 32 - QA - lz );  /* Q( -rshifts ) */
            num  = silk_ADD_LSHIFT32( num,  silk_SMMUL( CAb[ n - k ],             Atmp1 ), 32 - QA - lz );  /* Q( -rshifts ) */
            nrg  = silk_ADD_LSHIFT32( nrg,  silk_SMMUL( silk_ADD32( CAb[ k + 1 ], CAf[ k + 1 ] ),
                                                                                Atmp1 ), 32 - QA - lz );    /* Q( 1-rshifts ) */
        }
        CAf[ n + 1 ] = tmp1;                                                                            /* Q( -rshifts ) */
        CAb[ n + 1 ] = tmp2;                                                                            /* Q( -rshifts ) */
        num = silk_ADD32( num, tmp2 );                                                                  /* Q( -rshifts ) */
        num = silk_LSHIFT32( -num, 1 );                                                                 /* Q( 1-rshifts ) */

        /* Calculate the next order reflection (parcor) coefficient */
        if( silk_abs( num ) < nrg ) {
            rc_Q31 = silk_DIV32_varQ( num, nrg, 31 );
        } else {
            rc_Q31 = ( num > 0 ) ? silk_int32_MAX : silk_int32_MIN;
        }

        /* Update inverse prediction gain */
        tmp1 = ( (opus_int32)1 << 30 ) - silk_SMMUL( rc_Q31, rc_Q31 );
        tmp1 = silk_LSHIFT( silk_SMMUL( invGain_Q30, tmp1 ), 2 );
        if( tmp1 <= minInvGain_Q30 ) {
            /* Max prediction gain exceeded; set reflection coefficient such that max prediction gain is exactly hit */
            tmp2 = ( (opus_int32)1 << 30 ) - silk_DIV32_varQ( minInvGain_Q30, invGain_Q30, 30 );            /* Q30 */
            rc_Q31 = silk_SQRT_APPROX( tmp2 );                                                  /* Q15 */
            /* Newton-Raphson iteration */
            rc_Q31 = silk_RSHIFT32( rc_Q31 + silk_DIV32( tmp2, rc_Q31 ), 1 );                   /* Q15 */
            rc_Q31 = silk_LSHIFT32( rc_Q31, 16 );                                               /* Q31 */
            if( num < 0 ) {
                /* Ensure adjusted reflection coefficients has the original sign */
                rc_Q31 = -rc_Q31;
            }
            invGain_Q30 = minInvGain_Q30;
            reached_max_gain = 1;
        } else {
            invGain_Q30 = tmp1;
        }

        /* Update the AR coefficients */
        for( k = 0; k < (n + 1) >> 1; k++ ) {
            tmp1 = Af_QA[ k ];                                                                  /* QA */
            tmp2 = Af_QA[ n - k - 1 ];                                                          /* QA */
            Af_QA[ k ]         = silk_ADD_LSHIFT32( tmp1, silk_SMMUL( tmp2, rc_Q31 ), 1 );      /* QA */
            Af_QA[ n - k - 1 ] = silk_ADD_LSHIFT32( tmp2, silk_SMMUL( tmp1, rc_Q31 ), 1 );      /* QA */
        }
        Af_QA[ n ] = silk_RSHIFT32( rc_Q31, 31 - QA );                                          /* QA */

        if( reached_max_gain ) {
            /* Reached max prediction gain; set remaining coefficients to zero and exit loop */
            for( k = n + 1; k < D; k++ ) {
                Af_QA[ k ] = 0;
            }
            break;
        }

        /* Update C * Af and C * Ab */
        for( k = 0; k <= n + 1; k++ ) {
            tmp1 = CAf[ k ];                                                                    /* Q( -rshifts ) */
            tmp2 = CAb[ n - k + 1 ];                                                            /* Q( -rshifts ) */
            CAf[ k ]         = silk_ADD_LSHIFT32( tmp1, silk_SMMUL( tmp2, rc_Q31 ), 1 );        /* Q( -rshifts ) */
            CAb[ n - k + 1 ] = silk_ADD_LSHIFT32( tmp2, silk_SMMUL( tmp1, rc_Q31 ), 1 );        /* Q( -rshifts ) */
        }
    }

    if( reached_max_gain ) {
        for( k = 0; k < D; k++ ) {
            /* Scale coefficients */
            A_Q16[ k ] = -silk_RSHIFT_ROUND( Af_QA[ k ], QA - 16 );
        }
        /* Subtract energy of preceding samples from C0 */
        if( rshifts > 0 ) {
            for( s = 0; s < nb_subfr; s++ ) {
                x_ptr = x + s * subfr_length;
                C0 -= (opus_int32)silk_RSHIFT64( silk_inner_prod16_aligned_64( x_ptr, x_ptr, D ), rshifts );
            }
        } else {
            for( s = 0; s < nb_subfr; s++ ) {
                x_ptr = x + s * subfr_length;
                C0 -= silk_LSHIFT32( silk_inner_prod_aligned( x_ptr, x_ptr, D ), -rshifts );
            }
        }
        /* Approximate residual energy */
        *res_nrg = silk_LSHIFT( silk_SMMUL( invGain_Q30, C0 ), 2 );
        *res_nrg_Q = -rshifts;
    } else {
        /* Return residual energy */
        nrg  = CAf[ 0 ];                                                                            /* Q( -rshifts ) */
        tmp1 = (opus_int32)1 << 16;                                                                             /* Q16 */
        for( k = 0; k < D; k++ ) {
            Atmp1 = silk_RSHIFT_ROUND( Af_QA[ k ], QA - 16 );                                       /* Q16 */
            nrg  = silk_SMLAWW( nrg, CAf[ k + 1 ], Atmp1 );                                         /* Q( -rshifts ) */
            tmp1 = silk_SMLAWW( tmp1, Atmp1, Atmp1 );                                               /* Q16 */
            A_Q16[ k ] = -Atmp1;
        }
        *res_nrg = silk_SMLAWW( nrg, silk_SMMUL( FIND_LPC_COND_FAC, C0 ), -tmp1 );                  /* Q( -rshifts ) */
        *res_nrg_Q = -rshifts;
    }   
}
/* notch filter just above Nyquist.                                         */
void silk_resampler_private_up2_HQ(
    opus_int32                      *S,             /* I/O  Resampler state [ 6 ]       */
    opus_int16                      *out,           /* O    Output signal [ 2 * len ]   */
    const opus_int16                *in,            /* I    Input signal [ len ]        */
    opus_int32                      len             /* I    Number of input samples     */
)
{
    opus_int32 k;
    opus_int32 in32, out32_1, out32_2, Y, X;

    silk_assert( silk_resampler_up2_hq_0[ 0 ] > 0 );
    silk_assert( silk_resampler_up2_hq_0[ 1 ] > 0 );
    silk_assert( silk_resampler_up2_hq_0[ 2 ] < 0 );
    silk_assert( silk_resampler_up2_hq_1[ 0 ] > 0 );
    silk_assert( silk_resampler_up2_hq_1[ 1 ] > 0 );
    silk_assert( silk_resampler_up2_hq_1[ 2 ] < 0 );

    /* Internal variables and state are in Q10 format */
    for( k = 0; k < len; k++ ) {
        /* Convert to Q10 */
        in32 = silk_LSHIFT( (opus_int32)in[ k ], 10 );

        /* First all-pass section for even output sample */
        Y       = silk_SUB32( in32, S[ 0 ] );
        X       = silk_SMULWB( Y, silk_resampler_up2_hq_0[ 0 ] );
        out32_1 = silk_ADD32( S[ 0 ], X );
        S[ 0 ]  = silk_ADD32( in32, X );

        /* Second all-pass section for even output sample */
        Y       = silk_SUB32( out32_1, S[ 1 ] );
        X       = silk_SMULWB( Y, silk_resampler_up2_hq_0[ 1 ] );
        out32_2 = silk_ADD32( S[ 1 ], X );
        S[ 1 ]  = silk_ADD32( out32_1, X );

        /* Third all-pass section for even output sample */
        Y       = silk_SUB32( out32_2, S[ 2 ] );
        X       = silk_SMLAWB( Y, Y, silk_resampler_up2_hq_0[ 2 ] );
        out32_1 = silk_ADD32( S[ 2 ], X );
        S[ 2 ]  = silk_ADD32( out32_2, X );

        /* Apply gain in Q15, convert back to int16 and store to output */
        out[ 2 * k ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( out32_1, 10 ) );

        /* First all-pass section for odd output sample */
        Y       = silk_SUB32( in32, S[ 3 ] );
        X       = silk_SMULWB( Y, silk_resampler_up2_hq_1[ 0 ] );
        out32_1 = silk_ADD32( S[ 3 ], X );
        S[ 3 ]  = silk_ADD32( in32, X );

        /* Second all-pass section for odd output sample */
        Y       = silk_SUB32( out32_1, S[ 4 ] );
        X       = silk_SMULWB( Y, silk_resampler_up2_hq_1[ 1 ] );
        out32_2 = silk_ADD32( S[ 4 ], X );
        S[ 4 ]  = silk_ADD32( out32_1, X );

        /* Third all-pass section for odd output sample */
        Y       = silk_SUB32( out32_2, S[ 5 ] );
        X       = silk_SMLAWB( Y, Y, silk_resampler_up2_hq_1[ 2 ] );
        out32_1 = silk_ADD32( S[ 5 ], X );
        S[ 5 ]  = silk_ADD32( out32_2, X );

        /* Apply gain in Q15, convert back to int16 and store to output */
        out[ 2 * k + 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( out32_1, 10 ) );
    }
}
Exemple #23
0
/* Downsample by a factor 2/3, low quality */
void silk_resampler_down2_3(
    opus_int32                  *S,                 /* I/O  State vector [ 6 ]                                          */
    opus_int16                  *out,               /* O    Output signal [ floor(2*inLen/3) ]                          */
    const opus_int16            *in,                /* I    Input signal [ inLen ]                                      */
    opus_int32                  inLen               /* I    Number of input samples                                     */
)
{
    opus_int32 nSamplesIn, counter, res_Q6;
    VARDECL( opus_int32, buf );
    opus_int32 *buf_ptr;
    SAVE_STACK;

    ALLOC( buf, RESAMPLER_MAX_BATCH_SIZE_IN + ORDER_FIR, opus_int32 );

    /* Copy buffered samples to start of buffer */
    silk_memcpy( buf, S, ORDER_FIR * sizeof( opus_int32 ) );

    /* Iterate over blocks of frameSizeIn input samples */
    while( 1 ) {
        nSamplesIn = silk_min( inLen, RESAMPLER_MAX_BATCH_SIZE_IN );

        /* Second-order AR filter (output in Q8) */
        silk_resampler_private_AR2( &S[ ORDER_FIR ], &buf[ ORDER_FIR ], in,
            silk_Resampler_2_3_COEFS_LQ, nSamplesIn );

        /* Interpolate filtered signal */
        buf_ptr = buf;
        counter = nSamplesIn;
        while( counter > 2 ) {
            /* Inner product */
            res_Q6 = silk_SMULWB(         buf_ptr[ 0 ], silk_Resampler_2_3_COEFS_LQ[ 2 ] );
            res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 1 ], silk_Resampler_2_3_COEFS_LQ[ 3 ] );
            res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 2 ], silk_Resampler_2_3_COEFS_LQ[ 5 ] );
            res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 3 ], silk_Resampler_2_3_COEFS_LQ[ 4 ] );

            /* Scale down, saturate and store in output array */
            *out++ = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( res_Q6, 6 ) );

            res_Q6 = silk_SMULWB(         buf_ptr[ 1 ], silk_Resampler_2_3_COEFS_LQ[ 4 ] );
            res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 2 ], silk_Resampler_2_3_COEFS_LQ[ 5 ] );
            res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 3 ], silk_Resampler_2_3_COEFS_LQ[ 3 ] );
            res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 4 ], silk_Resampler_2_3_COEFS_LQ[ 2 ] );

            /* Scale down, saturate and store in output array */
            *out++ = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( res_Q6, 6 ) );

            buf_ptr += 3;
            counter -= 3;
        }

        in += nSamplesIn;
        inLen -= nSamplesIn;

        if( inLen > 0 ) {
            /* More iterations to do; copy last part of filtered signal to beginning of buffer */
            silk_memcpy( buf, &buf[ nSamplesIn ], ORDER_FIR * sizeof( opus_int32 ) );
        } else {
            break;
        }
    }

    /* Copy last part of filtered signal to the state for the next call */
    silk_memcpy( S, &buf[ nSamplesIn ], ORDER_FIR * sizeof( opus_int32 ) );
    RESTORE_STACK;
}
/* Compute reflection coefficients from input signal */
void silk_burg_modified_sse4_1(
    opus_int32                  *res_nrg,           /* O    Residual energy                                             */
    opus_int                    *res_nrg_Q,         /* O    Residual energy Q value                                     */
    opus_int32                  A_Q16[],            /* O    Prediction coefficients (length order)                      */
    const opus_int16            x[],                /* I    Input signal, length: nb_subfr * (D + subfr_length)       */
    const opus_int32            minInvGain_Q30,     /* I    Inverse of max prediction gain                              */
    const opus_int              subfr_length,       /* I    Input signal subframe length (incl. D preceding samples)    */
    const opus_int              nb_subfr,           /* I    Number of subframes stacked in x                            */
    const opus_int              D,                  /* I    Order                                                       */
    int                         arch                /* I    Run-time architecture                                       */
)
{
    opus_int         k, n, s, lz, rshifts, rshifts_extra, reached_max_gain;
    opus_int32       C0, num, nrg, rc_Q31, invGain_Q30, Atmp_QA, Atmp1, tmp1, tmp2, x1, x2;
    const opus_int16 *x_ptr;
    opus_int32       C_first_row[ SILK_MAX_ORDER_LPC ];
    opus_int32       C_last_row[  SILK_MAX_ORDER_LPC ];
    opus_int32       Af_QA[       SILK_MAX_ORDER_LPC ];
    opus_int32       CAf[ SILK_MAX_ORDER_LPC + 1 ];
    opus_int32       CAb[ SILK_MAX_ORDER_LPC + 1 ];
    opus_int32       xcorr[ SILK_MAX_ORDER_LPC ];

    __m128i FIRST_3210, LAST_3210, ATMP_3210, TMP1_3210, TMP2_3210, T1_3210, T2_3210, PTR_3210, SUBFR_3210, X1_3210, X2_3210;
    __m128i CONST1 = _mm_set1_epi32(1);

    silk_assert(subfr_length * nb_subfr <= MAX_FRAME_SIZE);

    /* Compute autocorrelations, added over subframes */
    silk_sum_sqr_shift(&C0, &rshifts, x, nb_subfr * subfr_length);
    if(rshifts > MAX_RSHIFTS) {
        C0 = silk_LSHIFT32(C0, rshifts - MAX_RSHIFTS);
        silk_assert(C0 > 0);
        rshifts = MAX_RSHIFTS;
    } else {
        lz = silk_CLZ32(C0) - 1;
        rshifts_extra = N_BITS_HEAD_ROOM - lz;
        if(rshifts_extra > 0) {
            rshifts_extra = silk_min(rshifts_extra, MAX_RSHIFTS - rshifts);
            C0 = silk_RSHIFT32(C0, rshifts_extra);
        } else {
            rshifts_extra = silk_max(rshifts_extra, MIN_RSHIFTS - rshifts);
            C0 = silk_LSHIFT32(C0, -rshifts_extra);
        }
        rshifts += rshifts_extra;
    }
    CAb[ 0 ] = CAf[ 0 ] = C0 + silk_SMMUL(SILK_FIX_CONST(FIND_LPC_COND_FAC, 32), C0) + 1;                                /* Q(-rshifts) */
    silk_memset(C_first_row, 0, SILK_MAX_ORDER_LPC * sizeof(opus_int32));
    if(rshifts > 0) {
        for(s = 0; s < nb_subfr; s++) {
            x_ptr = x + s * subfr_length;
            for(n = 1; n < D + 1; n++) {
                C_first_row[ n - 1 ] += (opus_int32)silk_RSHIFT64(
                    silk_inner_prod16_aligned_64(x_ptr, x_ptr + n, subfr_length - n, arch), rshifts);
            }
        }
    } else {
        for(s = 0; s < nb_subfr; s++) {
            int i;
            opus_int32 d;
            x_ptr = x + s * subfr_length;
            celt_pitch_xcorr(x_ptr, x_ptr + 1, xcorr, subfr_length - D, D, arch);
            for(n = 1; n < D + 1; n++) {
               for (i = n + subfr_length - D, d = 0; i < subfr_length; i++)
                  d = MAC16_16(d, x_ptr[ i ], x_ptr[ i - n ]);
               xcorr[ n - 1 ] += d;
            }
            for(n = 1; n < D + 1; n++) {
                C_first_row[ n - 1 ] += silk_LSHIFT32(xcorr[ n - 1 ], -rshifts);
            }
        }
    }
    silk_memcpy(C_last_row, C_first_row, SILK_MAX_ORDER_LPC * sizeof(opus_int32));

    /* Initialize */
    CAb[ 0 ] = CAf[ 0 ] = C0 + silk_SMMUL(SILK_FIX_CONST(FIND_LPC_COND_FAC, 32), C0) + 1;                                /* Q(-rshifts) */

    invGain_Q30 = (opus_int32)1 << 30;
    reached_max_gain = 0;
    for(n = 0; n < D; n++) {
        /* Update first row of correlation matrix (without first element) */
        /* Update last row of correlation matrix (without last element, stored in reversed order) */
        /* Update C * Af */
        /* Update C * flipud(Af) (stored in reversed order) */
        if(rshifts > -2) {
            for(s = 0; s < nb_subfr; s++) {
                x_ptr = x + s * subfr_length;
                x1  = -silk_LSHIFT32((opus_int32)x_ptr[ n ],                    16 - rshifts);        /* Q(16-rshifts) */
                x2  = -silk_LSHIFT32((opus_int32)x_ptr[ subfr_length - n - 1 ], 16 - rshifts);        /* Q(16-rshifts) */
                tmp1 = silk_LSHIFT32((opus_int32)x_ptr[ n ],                    QA - 16);             /* Q(QA-16) */
                tmp2 = silk_LSHIFT32((opus_int32)x_ptr[ subfr_length - n - 1 ], QA - 16);             /* Q(QA-16) */
                for(k = 0; k < n; k++) {
                    C_first_row[ k ] = silk_SMLAWB(C_first_row[ k ], x1, x_ptr[ n - k - 1 ]           ); /* Q(-rshifts) */
                    C_last_row[ k ]  = silk_SMLAWB(C_last_row[ k ],  x2, x_ptr[ subfr_length - n + k ]); /* Q(-rshifts) */
                    Atmp_QA = Af_QA[ k ];
                    tmp1 = silk_SMLAWB(tmp1, Atmp_QA, x_ptr[ n - k - 1 ]           );                 /* Q(QA-16) */
                    tmp2 = silk_SMLAWB(tmp2, Atmp_QA, x_ptr[ subfr_length - n + k ]);                 /* Q(QA-16) */
                }
                tmp1 = silk_LSHIFT32(-tmp1, 32 - QA - rshifts);                                       /* Q(16-rshifts) */
                tmp2 = silk_LSHIFT32(-tmp2, 32 - QA - rshifts);                                       /* Q(16-rshifts) */
                for(k = 0; k <= n; k++) {
                    CAf[ k ] = silk_SMLAWB(CAf[ k ], tmp1, x_ptr[ n - k ]                   );        /* Q(-rshift) */
                    CAb[ k ] = silk_SMLAWB(CAb[ k ], tmp2, x_ptr[ subfr_length - n + k - 1 ]);        /* Q(-rshift) */
                }
            }
        } else {
            for(s = 0; s < nb_subfr; s++) {
                x_ptr = x + s * subfr_length;
                x1  = -silk_LSHIFT32((opus_int32)x_ptr[ n ],                    -rshifts);            /* Q(-rshifts) */
                x2  = -silk_LSHIFT32((opus_int32)x_ptr[ subfr_length - n - 1 ], -rshifts);            /* Q(-rshifts) */
                tmp1 = silk_LSHIFT32((opus_int32)x_ptr[ n ],                    17);                  /* Q17 */
                tmp2 = silk_LSHIFT32((opus_int32)x_ptr[ subfr_length - n - 1 ], 17);                  /* Q17 */

                X1_3210 = _mm_set1_epi32(x1);
                X2_3210 = _mm_set1_epi32(x2);
                TMP1_3210 = _mm_setzero_si128();
                TMP2_3210 = _mm_setzero_si128();
                for(k = 0; k < n - 3; k += 4) {
                    PTR_3210   = OP_CVTEPI16_EPI32_M64(&x_ptr[ n - k - 1 - 3 ]);
                    SUBFR_3210 = OP_CVTEPI16_EPI32_M64(&x_ptr[ subfr_length - n + k ]);
                    FIRST_3210 = _mm_loadu_si128((__m128i *)&C_first_row[ k ]);
                    PTR_3210   = _mm_shuffle_epi32(PTR_3210,  _MM_SHUFFLE(0, 1, 2, 3));
                    LAST_3210  = _mm_loadu_si128((__m128i *)&C_last_row[ k ]);
                    ATMP_3210  = _mm_loadu_si128((__m128i *)&Af_QA[ k ]);

                    T1_3210 = _mm_mullo_epi32(PTR_3210, X1_3210);
                    T2_3210 = _mm_mullo_epi32(SUBFR_3210, X2_3210);

                    ATMP_3210 = _mm_srai_epi32(ATMP_3210, 7);
                    ATMP_3210 = _mm_add_epi32(ATMP_3210, CONST1);
                    ATMP_3210 = _mm_srai_epi32(ATMP_3210, 1);

                    FIRST_3210 = _mm_add_epi32(FIRST_3210, T1_3210);
                    LAST_3210 = _mm_add_epi32(LAST_3210, T2_3210);

                    PTR_3210   = _mm_mullo_epi32(ATMP_3210, PTR_3210);
                    SUBFR_3210   = _mm_mullo_epi32(ATMP_3210, SUBFR_3210);

                    _mm_storeu_si128((__m128i *)&C_first_row[ k ], FIRST_3210);
                    _mm_storeu_si128((__m128i *)&C_last_row[ k ], LAST_3210);

                    TMP1_3210 = _mm_add_epi32(TMP1_3210, PTR_3210);
                    TMP2_3210 = _mm_add_epi32(TMP2_3210, SUBFR_3210);
                }

                TMP1_3210 = _mm_add_epi32(TMP1_3210, _mm_unpackhi_epi64(TMP1_3210, TMP1_3210));
                TMP2_3210 = _mm_add_epi32(TMP2_3210, _mm_unpackhi_epi64(TMP2_3210, TMP2_3210));
                TMP1_3210 = _mm_add_epi32(TMP1_3210, _mm_shufflelo_epi16(TMP1_3210, 0x0E));
                TMP2_3210 = _mm_add_epi32(TMP2_3210, _mm_shufflelo_epi16(TMP2_3210, 0x0E));

                tmp1 += _mm_cvtsi128_si32(TMP1_3210);
                tmp2 += _mm_cvtsi128_si32(TMP2_3210);

                for(; k < n; k++) {
                    C_first_row[ k ] = silk_MLA(C_first_row[ k ], x1, x_ptr[ n - k - 1 ]           ); /* Q(-rshifts) */
                    C_last_row[ k ]  = silk_MLA(C_last_row[ k ],  x2, x_ptr[ subfr_length - n + k ]); /* Q(-rshifts) */
                    Atmp1 = silk_RSHIFT_ROUND(Af_QA[ k ], QA - 17);                                   /* Q17 */
                    tmp1 = silk_MLA(tmp1, x_ptr[ n - k - 1 ],            Atmp1);                      /* Q17 */
                    tmp2 = silk_MLA(tmp2, x_ptr[ subfr_length - n + k ], Atmp1);                      /* Q17 */
                }

                tmp1 = -tmp1;                /* Q17 */
                tmp2 = -tmp2;                /* Q17 */

                {
                    __m128i xmm_tmp1, xmm_tmp2;
                    __m128i xmm_x_ptr_n_k_x2x0, xmm_x_ptr_n_k_x3x1;
                    __m128i xmm_x_ptr_sub_x2x0, xmm_x_ptr_sub_x3x1;

                    xmm_tmp1 = _mm_set1_epi32(tmp1);
                    xmm_tmp2 = _mm_set1_epi32(tmp2);

                    for(k = 0; k <= n - 3; k += 4) {
                        xmm_x_ptr_n_k_x2x0 = OP_CVTEPI16_EPI32_M64(&x_ptr[ n - k - 3 ]);
                        xmm_x_ptr_sub_x2x0 = OP_CVTEPI16_EPI32_M64(&x_ptr[ subfr_length - n + k - 1 ]);

                        xmm_x_ptr_n_k_x2x0 = _mm_shuffle_epi32(xmm_x_ptr_n_k_x2x0, _MM_SHUFFLE(0, 1, 2, 3));

                        xmm_x_ptr_n_k_x2x0 = _mm_slli_epi32(xmm_x_ptr_n_k_x2x0, -rshifts - 1);
                        xmm_x_ptr_sub_x2x0 = _mm_slli_epi32(xmm_x_ptr_sub_x2x0, -rshifts - 1);

                        /* equal shift right 4 bytes, xmm_x_ptr_n_k_x3x1 = _mm_srli_si128(xmm_x_ptr_n_k_x2x0, 4)*/
                        xmm_x_ptr_n_k_x3x1 = _mm_shuffle_epi32(xmm_x_ptr_n_k_x2x0, _MM_SHUFFLE(0, 3, 2, 1));
                        xmm_x_ptr_sub_x3x1 = _mm_shuffle_epi32(xmm_x_ptr_sub_x2x0, _MM_SHUFFLE(0, 3, 2, 1));

                        xmm_x_ptr_n_k_x2x0 = _mm_mul_epi32(xmm_x_ptr_n_k_x2x0, xmm_tmp1);
                        xmm_x_ptr_n_k_x3x1 = _mm_mul_epi32(xmm_x_ptr_n_k_x3x1, xmm_tmp1);
                        xmm_x_ptr_sub_x2x0 = _mm_mul_epi32(xmm_x_ptr_sub_x2x0, xmm_tmp2);
                        xmm_x_ptr_sub_x3x1 = _mm_mul_epi32(xmm_x_ptr_sub_x3x1, xmm_tmp2);

                        xmm_x_ptr_n_k_x2x0 = _mm_srli_epi64(xmm_x_ptr_n_k_x2x0, 16);
                        xmm_x_ptr_n_k_x3x1 = _mm_slli_epi64(xmm_x_ptr_n_k_x3x1, 16);
                        xmm_x_ptr_sub_x2x0 = _mm_srli_epi64(xmm_x_ptr_sub_x2x0, 16);
                        xmm_x_ptr_sub_x3x1 = _mm_slli_epi64(xmm_x_ptr_sub_x3x1, 16);

                        xmm_x_ptr_n_k_x2x0 = _mm_blend_epi16(xmm_x_ptr_n_k_x2x0, xmm_x_ptr_n_k_x3x1, 0xCC);
                        xmm_x_ptr_sub_x2x0 = _mm_blend_epi16(xmm_x_ptr_sub_x2x0, xmm_x_ptr_sub_x3x1, 0xCC);

                        X1_3210  = _mm_loadu_si128((__m128i *)&CAf[ k ]);
                        PTR_3210 = _mm_loadu_si128((__m128i *)&CAb[ k ]);

                        X1_3210  = _mm_add_epi32(X1_3210, xmm_x_ptr_n_k_x2x0);
                        PTR_3210 = _mm_add_epi32(PTR_3210, xmm_x_ptr_sub_x2x0);

                        _mm_storeu_si128((__m128i *)&CAf[ k ], X1_3210);
                        _mm_storeu_si128((__m128i *)&CAb[ k ], PTR_3210);
                    }

                    for(; k <= n; k++) {
                        CAf[ k ] = silk_SMLAWW(CAf[ k ], tmp1,
                            silk_LSHIFT32((opus_int32)x_ptr[ n - k ], -rshifts - 1));                    /* Q(-rshift) */
                        CAb[ k ] = silk_SMLAWW(CAb[ k ], tmp2,
                            silk_LSHIFT32((opus_int32)x_ptr[ subfr_length - n + k - 1 ], -rshifts - 1)); /* Q(-rshift) */
                    }
                }
            }
        }

        /* Calculate nominator and denominator for the next order reflection (parcor) coefficient */
        tmp1 = C_first_row[ n ];                                                                        /* Q(-rshifts) */
        tmp2 = C_last_row[ n ];                                                                         /* Q(-rshifts) */
        num  = 0;                                                                                       /* Q(-rshifts) */
        nrg  = silk_ADD32(CAb[ 0 ], CAf[ 0 ]);                                                        /* Q(1-rshifts) */
        for(k = 0; k < n; k++) {
            Atmp_QA = Af_QA[ k ];
            lz = silk_CLZ32(silk_abs(Atmp_QA)) - 1;
            lz = silk_min(32 - QA, lz);
            Atmp1 = silk_LSHIFT32(Atmp_QA, lz);                                                       /* Q(QA + lz) */

            tmp1 = silk_ADD_LSHIFT32(tmp1, silk_SMMUL(C_last_row[  n - k - 1 ], Atmp1), 32 - QA - lz);  /* Q(-rshifts) */
            tmp2 = silk_ADD_LSHIFT32(tmp2, silk_SMMUL(C_first_row[ n - k - 1 ], Atmp1), 32 - QA - lz);  /* Q(-rshifts) */
            num  = silk_ADD_LSHIFT32(num,  silk_SMMUL(CAb[ n - k ],             Atmp1), 32 - QA - lz);  /* Q(-rshifts) */
            nrg  = silk_ADD_LSHIFT32(nrg,  silk_SMMUL(silk_ADD32(CAb[ k + 1 ], CAf[ k + 1 ]),
                                                                                Atmp1), 32 - QA - lz);    /* Q(1-rshifts) */
        }
        CAf[ n + 1 ] = tmp1;                                                                            /* Q(-rshifts) */
        CAb[ n + 1 ] = tmp2;                                                                            /* Q(-rshifts) */
        num = silk_ADD32(num, tmp2);                                                                  /* Q(-rshifts) */
        num = silk_LSHIFT32(-num, 1);                                                                 /* Q(1-rshifts) */

        /* Calculate the next order reflection (parcor) coefficient */
        if(silk_abs(num) < nrg) {
            rc_Q31 = silk_DIV32_varQ(num, nrg, 31);
        } else {
            rc_Q31 = (num > 0) ? silk_int32_MAX : silk_int32_MIN;
        }

        /* Update inverse prediction gain */
        tmp1 = ((opus_int32)1 << 30) - silk_SMMUL(rc_Q31, rc_Q31);
        tmp1 = silk_LSHIFT(silk_SMMUL(invGain_Q30, tmp1), 2);
        if(tmp1 <= minInvGain_Q30) {
            /* Max prediction gain exceeded; set reflection coefficient such that max prediction gain is exactly hit */
            tmp2 = ((opus_int32)1 << 30) - silk_DIV32_varQ(minInvGain_Q30, invGain_Q30, 30);            /* Q30 */
            rc_Q31 = silk_SQRT_APPROX(tmp2);                                                  /* Q15 */
            /* Newton-Raphson iteration */
            rc_Q31 = silk_RSHIFT32(rc_Q31 + silk_DIV32(tmp2, rc_Q31), 1);                   /* Q15 */
            rc_Q31 = silk_LSHIFT32(rc_Q31, 16);                                               /* Q31 */
            if(num < 0) {
                /* Ensure adjusted reflection coefficients has the original sign */
                rc_Q31 = -rc_Q31;
            }
            invGain_Q30 = minInvGain_Q30;
            reached_max_gain = 1;
        } else {
            invGain_Q30 = tmp1;
        }

        /* Update the AR coefficients */
        for(k = 0; k < (n + 1) >> 1; k++) {
            tmp1 = Af_QA[ k ];                                                                  /* QA */
            tmp2 = Af_QA[ n - k - 1 ];                                                          /* QA */
            Af_QA[ k ]         = silk_ADD_LSHIFT32(tmp1, silk_SMMUL(tmp2, rc_Q31), 1);      /* QA */
            Af_QA[ n - k - 1 ] = silk_ADD_LSHIFT32(tmp2, silk_SMMUL(tmp1, rc_Q31), 1);      /* QA */
        }
        Af_QA[ n ] = silk_RSHIFT32(rc_Q31, 31 - QA);                                          /* QA */

        if(reached_max_gain) {
            /* Reached max prediction gain; set remaining coefficients to zero and exit loop */
            for(k = n + 1; k < D; k++) {
                Af_QA[ k ] = 0;
            }
            break;
        }

        /* Update C * Af and C * Ab */
        for(k = 0; k <= n + 1; k++) {
            tmp1 = CAf[ k ];                                                                    /* Q(-rshifts) */
            tmp2 = CAb[ n - k + 1 ];                                                            /* Q(-rshifts) */
            CAf[ k ]         = silk_ADD_LSHIFT32(tmp1, silk_SMMUL(tmp2, rc_Q31), 1);        /* Q(-rshifts) */
            CAb[ n - k + 1 ] = silk_ADD_LSHIFT32(tmp2, silk_SMMUL(tmp1, rc_Q31), 1);        /* Q(-rshifts) */
        }
    }

    if(reached_max_gain) {
        for(k = 0; k < D; k++) {
            /* Scale coefficients */
            A_Q16[ k ] = -silk_RSHIFT_ROUND(Af_QA[ k ], QA - 16);
        }
        /* Subtract energy of preceding samples from C0 */
        if(rshifts > 0) {
            for(s = 0; s < nb_subfr; s++) {
                x_ptr = x + s * subfr_length;
                C0 -= (opus_int32)silk_RSHIFT64(silk_inner_prod16_aligned_64(x_ptr, x_ptr, D, arch), rshifts);
            }
        } else {
            for(s = 0; s < nb_subfr; s++) {
                x_ptr = x + s * subfr_length;
                C0 -= silk_LSHIFT32(silk_inner_prod_aligned(x_ptr, x_ptr, D, arch), -rshifts);
            }
        }
        /* Approximate residual energy */
        *res_nrg = silk_LSHIFT(silk_SMMUL(invGain_Q30, C0), 2);
        *res_nrg_Q = -rshifts;
    } else {
        /* Return residual energy */
        nrg  = CAf[ 0 ];                                                                            /* Q(-rshifts) */
        tmp1 = (opus_int32)1 << 16;                                                                             /* Q16 */
        for(k = 0; k < D; k++) {
            Atmp1 = silk_RSHIFT_ROUND(Af_QA[ k ], QA - 16);                                       /* Q16 */
            nrg  = silk_SMLAWW(nrg, CAf[ k + 1 ], Atmp1);                                         /* Q(-rshifts) */
            tmp1 = silk_SMLAWW(tmp1, Atmp1, Atmp1);                                               /* Q16 */
            A_Q16[ k ] = -Atmp1;
        }
        *res_nrg = silk_SMLAWW(nrg, silk_SMMUL(SILK_FIX_CONST(FIND_LPC_COND_FAC, 32), C0), -tmp1);/* Q(-rshifts) */
        *res_nrg_Q = -rshifts;
    }
}
Exemple #25
0
/* If not all roots are found, the a_Q16 coefficients are bandwidth expanded until convergence. */
void silk_A2NLSF(
    opus_int16                  *NLSF,              /* O    Normalized Line Spectral Frequencies in Q15 (0..2^15-1) [d] */
    opus_int32                  *a_Q16,             /* I/O  Monic whitening filter coefficients in Q16 [d]              */
    const opus_int              d                   /* I    Filter order (must be even)                                 */
)
{
    opus_int      i, k, m, dd, root_ix, ffrac;
    opus_int32 xlo, xhi, xmid;
    opus_int32 ylo, yhi, ymid, thr;
    opus_int32 nom, den;
    opus_int32 P[ SILK_MAX_ORDER_LPC / 2 + 1 ];
    opus_int32 Q[ SILK_MAX_ORDER_LPC / 2 + 1 ];
    opus_int32 *PQ[ 2 ];
    opus_int32 *p;

    /* Store pointers to array */
    PQ[ 0 ] = P;
    PQ[ 1 ] = Q;

    dd = silk_RSHIFT( d, 1 );

    silk_A2NLSF_init( a_Q16, P, Q, dd );

    /* Find roots, alternating between P and Q */
    p = P;                          /* Pointer to polynomial */

    xlo = silk_LSFCosTab_FIX_Q12[ 0 ]; /* Q12*/
    ylo = silk_A2NLSF_eval_poly( p, xlo, dd );

    if( ylo < 0 ) {
        /* Set the first NLSF to zero and move on to the next */
        NLSF[ 0 ] = 0;
        p = Q;                      /* Pointer to polynomial */
        ylo = silk_A2NLSF_eval_poly( p, xlo, dd );
        root_ix = 1;                /* Index of current root */
    } else {
        root_ix = 0;                /* Index of current root */
    }
    k = 1;                          /* Loop counter */
    i = 0;                          /* Counter for bandwidth expansions applied */
    thr = 0;
    while( 1 ) {
        /* Evaluate polynomial */
        xhi = silk_LSFCosTab_FIX_Q12[ k ]; /* Q12 */
        yhi = silk_A2NLSF_eval_poly( p, xhi, dd );

        /* Detect zero crossing */
        if( ( ylo <= 0 && yhi >= thr ) || ( ylo >= 0 && yhi <= -thr ) ) {
            if( yhi == 0 ) {
                /* If the root lies exactly at the end of the current       */
                /* interval, look for the next root in the next interval    */
                thr = 1;
            } else {
                thr = 0;
            }
            /* Binary division */
            ffrac = -256;
            for( m = 0; m < BIN_DIV_STEPS_A2NLSF_FIX; m++ ) {
                /* Evaluate polynomial */
                xmid = silk_RSHIFT_ROUND( xlo + xhi, 1 );
                ymid = silk_A2NLSF_eval_poly( p, xmid, dd );

                /* Detect zero crossing */
                if( ( ylo <= 0 && ymid >= 0 ) || ( ylo >= 0 && ymid <= 0 ) ) {
                    /* Reduce frequency */
                    xhi = xmid;
                    yhi = ymid;
                } else {
                    /* Increase frequency */
                    xlo = xmid;
                    ylo = ymid;
                    ffrac = silk_ADD_RSHIFT( ffrac, 128, m );
                }
            }

            /* Interpolate */
            if( silk_abs( ylo ) < 65536 ) {
                /* Avoid dividing by zero */
                den = ylo - yhi;
                nom = silk_LSHIFT( ylo, 8 - BIN_DIV_STEPS_A2NLSF_FIX ) + silk_RSHIFT( den, 1 );
                if( den != 0 ) {
                    ffrac += silk_DIV32( nom, den );
                }
            } else {
                /* No risk of dividing by zero because abs(ylo - yhi) >= abs(ylo) >= 65536 */
                ffrac += silk_DIV32( ylo, silk_RSHIFT( ylo - yhi, 8 - BIN_DIV_STEPS_A2NLSF_FIX ) );
            }
            NLSF[ root_ix ] = (opus_int16)silk_min_32( silk_LSHIFT( (opus_int32)k, 8 ) + ffrac, silk_int16_MAX );

            silk_assert( NLSF[ root_ix ] >= 0 );

            root_ix++;        /* Next root */
            if( root_ix >= d ) {
                /* Found all roots */
                break;
            }
            /* Alternate pointer to polynomial */
            p = PQ[ root_ix & 1 ];

            /* Evaluate polynomial */
            xlo = silk_LSFCosTab_FIX_Q12[ k - 1 ]; /* Q12*/
            ylo = silk_LSHIFT( 1 - ( root_ix & 2 ), 12 );
        } else {
            /* Increment loop counter */
            k++;
            xlo = xhi;
            ylo = yhi;
            thr = 0;

            if( k > LSF_COS_TAB_SZ_FIX ) {
                i++;
                if( i > MAX_ITERATIONS_A2NLSF_FIX ) {
                    /* Set NLSFs to white spectrum and exit */
                    NLSF[ 0 ] = (opus_int16)silk_DIV32_16( 1 << 15, d + 1 );
                    for( k = 1; k < d; k++ ) {
                        NLSF[ k ] = (opus_int16)silk_SMULBB( k + 1, NLSF[ 0 ] );
                    }
                    return;
                }

                /* Error: Apply progressively more bandwidth expansion and run again */
                silk_bwexpander_32( a_Q16, d, 65536 - silk_SMULBB( 10 + i, i ) ); /* 10_Q16 = 0.00015*/

                silk_A2NLSF_init( a_Q16, P, Q, dd );
                p = P;                            /* Pointer to polynomial */
                xlo = silk_LSFCosTab_FIX_Q12[ 0 ]; /* Q12*/
                ylo = silk_A2NLSF_eval_poly( p, xlo, dd );
                if( ylo < 0 ) {
                    /* Set the first NLSF to zero and move on to the next */
                    NLSF[ 0 ] = 0;
                    p = Q;                        /* Pointer to polynomial */
                    ylo = silk_A2NLSF_eval_poly( p, xlo, dd );
                    root_ix = 1;                  /* Index of current root */
                } else {
                    root_ix = 0;                  /* Index of current root */
                }
                k = 1;                            /* Reset loop counter */
            }
        }
    }
}
Exemple #26
0
/* compute whitening filter coefficients from normalized line spectral frequencies */
void silk_NLSF2A(
    opus_int16                  *a_Q12,             /* O    monic whitening filter coefficients in Q12,  [ d ]          */
    const opus_int16            *NLSF,              /* I    normalized line spectral frequencies in Q15, [ d ]          */
    const opus_int              d                   /* I    filter order (should be even)                               */
)
{
    /* This ordering was found to maximize quality. It improves numerical accuracy of
       silk_NLSF2A_find_poly() compared to "standard" ordering. */
    static const unsigned char ordering16[16] = {
      0, 15, 8, 7, 4, 11, 12, 3, 2, 13, 10, 5, 6, 9, 14, 1
    };
    static const unsigned char ordering10[10] = {
      0, 9, 6, 3, 4, 5, 8, 1, 2, 7
    };
    const unsigned char *ordering;
    opus_int   k, i, dd;
    opus_int32 cos_LSF_QA[ SILK_MAX_ORDER_LPC ];
    opus_int32 P[ SILK_MAX_ORDER_LPC / 2 + 1 ], Q[ SILK_MAX_ORDER_LPC / 2 + 1 ];
    opus_int32 Ptmp, Qtmp, f_int, f_frac, cos_val, delta;
    opus_int32 a32_QA1[ SILK_MAX_ORDER_LPC ];
    opus_int32 maxabs, absval, idx=0, sc_Q16;

    silk_assert( LSF_COS_TAB_SZ_FIX == 128 );
    silk_assert( d==10||d==16 );

    /* convert LSFs to 2*cos(LSF), using piecewise linear curve from table */
    ordering = d == 16 ? ordering16 : ordering10;
    for( k = 0; k < d; k++ ) {
        silk_assert(NLSF[k] >= 0 );

        /* f_int on a scale 0-127 (rounded down) */
        f_int = silk_RSHIFT( NLSF[k], 15 - 7 );

        /* f_frac, range: 0..255 */
        f_frac = NLSF[k] - silk_LSHIFT( f_int, 15 - 7 );

        silk_assert(f_int >= 0);
        silk_assert(f_int < LSF_COS_TAB_SZ_FIX );

        /* Read start and end value from table */
        cos_val = silk_LSFCosTab_FIX_Q12[ f_int ];                /* Q12 */
        delta   = silk_LSFCosTab_FIX_Q12[ f_int + 1 ] - cos_val;  /* Q12, with a range of 0..200 */

        /* Linear interpolation */
        cos_LSF_QA[ordering[k]] = silk_RSHIFT_ROUND( silk_LSHIFT( cos_val, 8 ) + silk_MUL( delta, f_frac ), 20 - QA ); /* QA */
    }

    dd = silk_RSHIFT( d, 1 );

    /* generate even and odd polynomials using convolution */
    silk_NLSF2A_find_poly( P, &cos_LSF_QA[ 0 ], dd );
    silk_NLSF2A_find_poly( Q, &cos_LSF_QA[ 1 ], dd );

    /* convert even and odd polynomials to opus_int32 Q12 filter coefs */
    for( k = 0; k < dd; k++ ) {
        Ptmp = P[ k+1 ] + P[ k ];
        Qtmp = Q[ k+1 ] - Q[ k ];

        /* the Ptmp and Qtmp values at this stage need to fit in int32 */
        a32_QA1[ k ]     = -Qtmp - Ptmp;        /* QA+1 */
        a32_QA1[ d-k-1 ] =  Qtmp - Ptmp;        /* QA+1 */
    }

    /* Limit the maximum absolute value of the prediction coefficients, so that they'll fit in int16 */
    for( i = 0; i < 10; i++ ) {
        /* Find maximum absolute value and its index */
        maxabs = 0;
        for( k = 0; k < d; k++ ) {
            absval = silk_abs( a32_QA1[k] );
            if( absval > maxabs ) {
                maxabs = absval;
                idx    = k;
            }
        }
        maxabs = silk_RSHIFT_ROUND( maxabs, QA + 1 - 12 );                                          /* QA+1 -> Q12 */

        if( maxabs > silk_int16_MAX ) {
            /* Reduce magnitude of prediction coefficients */
            maxabs = silk_min( maxabs, 163838 );  /* ( silk_int32_MAX >> 14 ) + silk_int16_MAX = 163838 */
            sc_Q16 = SILK_FIX_CONST( 0.999, 16 ) - silk_DIV32( silk_LSHIFT( maxabs - silk_int16_MAX, 14 ),
                                        silk_RSHIFT32( silk_MUL( maxabs, idx + 1), 2 ) );
            silk_bwexpander_32( a32_QA1, d, sc_Q16 );
        } else {
            break;
        }
    }

    if( i == 10 ) {
        /* Reached the last iteration, clip the coefficients */
        for( k = 0; k < d; k++ ) {
            a_Q12[ k ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( a32_QA1[ k ], QA + 1 - 12 ) );  /* QA+1 -> Q12 */
            a32_QA1[ k ] = silk_LSHIFT( (opus_int32)a_Q12[ k ], QA + 1 - 12 );
        }
    } else {
        for( k = 0; k < d; k++ ) {
            a_Q12[ k ] = (opus_int16)silk_RSHIFT_ROUND( a32_QA1[ k ], QA + 1 - 12 );                /* QA+1 -> Q12 */
        }
    }

    for( i = 0; i < MAX_LPC_STABILIZE_ITERATIONS; i++ ) {
        if( silk_LPC_inverse_pred_gain( a_Q12, d ) < SILK_FIX_CONST( 1.0 / MAX_PREDICTION_POWER_GAIN, 30 ) ) {
            /* Prediction coefficients are (too close to) unstable; apply bandwidth expansion   */
            /* on the unscaled coefficients, convert to Q12 and measure again                   */
            silk_bwexpander_32( a32_QA1, d, 65536 - silk_LSHIFT( 2, i ) );
            for( k = 0; k < d; k++ ) {
                a_Q12[ k ] = (opus_int16)silk_RSHIFT_ROUND( a32_QA1[ k ], QA + 1 - 12 );            /* QA+1 -> Q12 */
            }
        } else {
            break;
        }
    }
}
Exemple #27
0
/* NLSF stabilizer, for a single input data vector */
void silk_NLSF_stabilize(
          opus_int16            *NLSF_Q15,          /* I/O   Unstable/stabilized normalized LSF vector in Q15 [L]       */
    const opus_int16            *NDeltaMin_Q15,     /* I     Min distance vector, NDeltaMin_Q15[L] must be >= 1 [L+1]   */
    const opus_int              L                   /* I     Number of NLSF parameters in the input vector              */
)
{
    opus_int   i, I=0, k, loops;
    opus_int16 center_freq_Q15;
    opus_int32 diff_Q15, min_diff_Q15, min_center_Q15, max_center_Q15;

    /* This is necessary to ensure an output within range of a opus_int16 */
    silk_assert( NDeltaMin_Q15[L] >= 1 );

    for( loops = 0; loops < MAX_LOOPS; loops++ ) {
        /**************************/
        /* Find smallest distance */
        /**************************/
        /* First element */
        min_diff_Q15 = NLSF_Q15[0] - NDeltaMin_Q15[0];
        I = 0;
        /* Middle elements */
        for( i = 1; i <= L-1; i++ ) {
            diff_Q15 = NLSF_Q15[i] - ( NLSF_Q15[i-1] + NDeltaMin_Q15[i] );
            if( diff_Q15 < min_diff_Q15 ) {
                min_diff_Q15 = diff_Q15;
                I = i;
            }
        }
        /* Last element */
        diff_Q15 = ( 1 << 15 ) - ( NLSF_Q15[L-1] + NDeltaMin_Q15[L] );
        if( diff_Q15 < min_diff_Q15 ) {
            min_diff_Q15 = diff_Q15;
            I = L;
        }

        /***************************************************/
        /* Now check if the smallest distance non-negative */
        /***************************************************/
        if( min_diff_Q15 >= 0 ) {
            return;
        }

        if( I == 0 ) {
            /* Move away from lower limit */
            NLSF_Q15[0] = NDeltaMin_Q15[0];

        } else if( I == L) {
            /* Move away from higher limit */
            NLSF_Q15[L-1] = ( 1 << 15 ) - NDeltaMin_Q15[L];

        } else {
            /* Find the lower extreme for the location of the current center frequency */
            min_center_Q15 = 0;
            for( k = 0; k < I; k++ ) {
                min_center_Q15 += NDeltaMin_Q15[k];
            }
            min_center_Q15 += silk_RSHIFT( NDeltaMin_Q15[I], 1 );

            /* Find the upper extreme for the location of the current center frequency */
            max_center_Q15 = 1 << 15;
            for( k = L; k > I; k-- ) {
                max_center_Q15 -= NDeltaMin_Q15[k];
            }
            max_center_Q15 -= silk_RSHIFT( NDeltaMin_Q15[I], 1 );

            /* Move apart, sorted by value, keeping the same center frequency */
            center_freq_Q15 = (opus_int16)silk_LIMIT_32( silk_RSHIFT_ROUND( (opus_int32)NLSF_Q15[I-1] + (opus_int32)NLSF_Q15[I], 1 ),
                min_center_Q15, max_center_Q15 );
            NLSF_Q15[I-1] = center_freq_Q15 - silk_RSHIFT( NDeltaMin_Q15[I], 1 );
            NLSF_Q15[I] = NLSF_Q15[I-1] + NDeltaMin_Q15[I];
        }
    }

    /* Safe and simple fall back method, which is less ideal than the above */
    if( loops == MAX_LOOPS )
    {
        /* Insertion sort (fast for already almost sorted arrays):   */
        /* Best case:  O(n)   for an already sorted array            */
        /* Worst case: O(n^2) for an inversely sorted array          */
        silk_insertion_sort_increasing_all_values_int16( &NLSF_Q15[0], L );

        /* First NLSF should be no less than NDeltaMin[0] */
        NLSF_Q15[0] = silk_max_int( NLSF_Q15[0], NDeltaMin_Q15[0] );

        /* Keep delta_min distance between the NLSFs */
        for( i = 1; i < L; i++ )
            NLSF_Q15[i] = silk_max_int( NLSF_Q15[i], NLSF_Q15[i-1] + NDeltaMin_Q15[i] );

        /* Last NLSF should be no higher than 1 - NDeltaMin[L] */
        NLSF_Q15[L-1] = silk_min_int( NLSF_Q15[L-1], (1<<15) - NDeltaMin_Q15[L] );

        /* Keep NDeltaMin distance between the NLSFs */
        for( i = L-2; i >= 0; i-- )
            NLSF_Q15[i] = silk_min_int( NLSF_Q15[i], NLSF_Q15[i+1] - NDeltaMin_Q15[i+1] );
    }
}
/* Compute reflection coefficients from input signal */
void silk_burg_modified(
    opus_int32                  *res_nrg,           /* O    Residual energy                                             */
    opus_int                    *res_nrg_Q,         /* O    Residual energy Q value                                     */
    opus_int32                  A_Q16[],            /* O    Prediction coefficients (length order)                      */
    const opus_int16            x[],                /* I    Input signal, length: nb_subfr * ( D + subfr_length )       */
    const opus_int              subfr_length,       /* I    Input signal subframe length (incl. D preceeding samples)   */
    const opus_int              nb_subfr,           /* I    Number of subframes stacked in x                            */
    const opus_int32            WhiteNoiseFrac_Q32, /* I    Fraction added to zero-lag autocorrelation                  */
    const opus_int              D                   /* I    Order                                                       */
)
{
    opus_int         k, n, s, lz, rshifts, rshifts_extra;
    opus_int32       C0, num, nrg, rc_Q31, Atmp_QA, Atmp1, tmp1, tmp2, x1, x2;
    const opus_int16 *x_ptr;

    opus_int32       C_first_row[ SILK_MAX_ORDER_LPC ];
    opus_int32       C_last_row[  SILK_MAX_ORDER_LPC ];
    opus_int32       Af_QA[       SILK_MAX_ORDER_LPC ];

    opus_int32       CAf[ SILK_MAX_ORDER_LPC + 1 ];
    opus_int32       CAb[ SILK_MAX_ORDER_LPC + 1 ];

    silk_assert( subfr_length * nb_subfr <= MAX_FRAME_SIZE );
    silk_assert( nb_subfr <= MAX_NB_SUBFR );


    /* Compute autocorrelations, added over subframes */
    silk_sum_sqr_shift( &C0, &rshifts, x, nb_subfr * subfr_length );
    if( rshifts > MAX_RSHIFTS ) {
        C0 = silk_LSHIFT32( C0, rshifts - MAX_RSHIFTS );
        silk_assert( C0 > 0 );
        rshifts = MAX_RSHIFTS;
    } else {
        lz = silk_CLZ32( C0 ) - 1;
        rshifts_extra = N_BITS_HEAD_ROOM - lz;
        if( rshifts_extra > 0 ) {
            rshifts_extra = silk_min( rshifts_extra, MAX_RSHIFTS - rshifts );
            C0 = silk_RSHIFT32( C0, rshifts_extra );
        } else {
            rshifts_extra = silk_max( rshifts_extra, MIN_RSHIFTS - rshifts );
            C0 = silk_LSHIFT32( C0, -rshifts_extra );
        }
        rshifts += rshifts_extra;
    }
    silk_memset( C_first_row, 0, SILK_MAX_ORDER_LPC * sizeof( opus_int32 ) );
    if( rshifts > 0 ) {
        for( s = 0; s < nb_subfr; s++ ) {
            x_ptr = x + s * subfr_length;
            for( n = 1; n < D + 1; n++ ) {
                C_first_row[ n - 1 ] += (opus_int32)silk_RSHIFT64(
                    silk_inner_prod16_aligned_64( x_ptr, x_ptr + n, subfr_length - n ), rshifts );
            }
        }
    } else {
        for( s = 0; s < nb_subfr; s++ ) {
            x_ptr = x + s * subfr_length;
            for( n = 1; n < D + 1; n++ ) {
                C_first_row[ n - 1 ] += silk_LSHIFT32(
                    silk_inner_prod_aligned( x_ptr, x_ptr + n, subfr_length - n ), -rshifts );
            }
        }
    }
    silk_memcpy( C_last_row, C_first_row, SILK_MAX_ORDER_LPC * sizeof( opus_int32 ) );

    /* Initialize */
    CAb[ 0 ] = CAf[ 0 ] = C0 + silk_SMMUL( WhiteNoiseFrac_Q32, C0 ) + 1;                                /* Q(-rshifts)*/

    for( n = 0; n < D; n++ ) {
        /* Update first row of correlation matrix (without first element) */
        /* Update last row of correlation matrix (without last element, stored in reversed order) */
        /* Update C * Af */
        /* Update C * flipud(Af) (stored in reversed order) */
        if( rshifts > -2 ) {
            for( s = 0; s < nb_subfr; s++ ) {
                x_ptr = x + s * subfr_length;
                x1  = -silk_LSHIFT32( (opus_int32)x_ptr[ n ],                    16 - rshifts );        /* Q(16-rshifts)*/
                x2  = -silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n - 1 ], 16 - rshifts );        /* Q(16-rshifts)*/
                tmp1 = silk_LSHIFT32( (opus_int32)x_ptr[ n ],                    QA - 16 );             /* Q(QA-16)*/
                tmp2 = silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n - 1 ], QA - 16 );             /* Q(QA-16)*/
                for( k = 0; k < n; k++ ) {
                    C_first_row[ k ] = silk_SMLAWB( C_first_row[ k ], x1, x_ptr[ n - k - 1 ]            ); /* Q( -rshifts )*/
                    C_last_row[ k ]  = silk_SMLAWB( C_last_row[ k ],  x2, x_ptr[ subfr_length - n + k ] ); /* Q( -rshifts )*/
                    Atmp_QA = Af_QA[ k ];
                    tmp1 = silk_SMLAWB( tmp1, Atmp_QA, x_ptr[ n - k - 1 ]            );                 /* Q(QA-16)*/
                    tmp2 = silk_SMLAWB( tmp2, Atmp_QA, x_ptr[ subfr_length - n + k ] );                 /* Q(QA-16)*/
                }
                tmp1 = silk_LSHIFT32( -tmp1, 32 - QA - rshifts );                                       /* Q(16-rshifts)*/
                tmp2 = silk_LSHIFT32( -tmp2, 32 - QA - rshifts );                                       /* Q(16-rshifts)*/
                for( k = 0; k <= n; k++ ) {
                    CAf[ k ] = silk_SMLAWB( CAf[ k ], tmp1, x_ptr[ n - k ]                    );        /* Q( -rshift )*/
                    CAb[ k ] = silk_SMLAWB( CAb[ k ], tmp2, x_ptr[ subfr_length - n + k - 1 ] );        /* Q( -rshift )*/
                }
            }
        } else {
            for( s = 0; s < nb_subfr; s++ ) {
                x_ptr = x + s * subfr_length;
                x1  = -silk_LSHIFT32( (opus_int32)x_ptr[ n ],                    -rshifts );            /* Q( -rshifts )*/
                x2  = -silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n - 1 ], -rshifts );            /* Q( -rshifts )*/
                tmp1 = silk_LSHIFT32( (opus_int32)x_ptr[ n ],                    17 );                  /* Q17*/
                tmp2 = silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n - 1 ], 17 );                  /* Q17*/
                for( k = 0; k < n; k++ ) {
                    C_first_row[ k ] = silk_MLA( C_first_row[ k ], x1, x_ptr[ n - k - 1 ]            ); /* Q( -rshifts )*/
                    C_last_row[ k ]  = silk_MLA( C_last_row[ k ],  x2, x_ptr[ subfr_length - n + k ] ); /* Q( -rshifts )*/
                    Atmp1 = silk_RSHIFT_ROUND( Af_QA[ k ], QA - 17 );                                   /* Q17*/
                    tmp1 = silk_MLA( tmp1, x_ptr[ n - k - 1 ],            Atmp1 );                      /* Q17*/
                    tmp2 = silk_MLA( tmp2, x_ptr[ subfr_length - n + k ], Atmp1 );                      /* Q17*/
                }
                tmp1 = -tmp1;                                                                           /* Q17*/
                tmp2 = -tmp2;                                                                           /* Q17*/
                for( k = 0; k <= n; k++ ) {
                    CAf[ k ] = silk_SMLAWW( CAf[ k ], tmp1,
                        silk_LSHIFT32( (opus_int32)x_ptr[ n - k ], -rshifts - 1 ) );                    /* Q( -rshift )*/
                    CAb[ k ] = silk_SMLAWW( CAb[ k ], tmp2,
                        silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n + k - 1 ], -rshifts - 1 ) ); /* Q( -rshift )*/
                }
            }
        }

        /* Calculate nominator and denominator for the next order reflection (parcor) coefficient */
        tmp1 = C_first_row[ n ];                                                                        /* Q( -rshifts )*/
        tmp2 = C_last_row[ n ];                                                                         /* Q( -rshifts )*/
        num  = 0;                                                                                       /* Q( -rshifts )*/
        nrg  = silk_ADD32( CAb[ 0 ], CAf[ 0 ] );                                                        /* Q( 1-rshifts )*/
        for( k = 0; k < n; k++ ) {
            Atmp_QA = Af_QA[ k ];
            lz = silk_CLZ32( silk_abs( Atmp_QA ) ) - 1;
            lz = silk_min( 32 - QA, lz );
            Atmp1 = silk_LSHIFT32( Atmp_QA, lz );                                                       /* Q( QA + lz )*/

            tmp1 = silk_ADD_LSHIFT32( tmp1, silk_SMMUL( C_last_row[  n - k - 1 ], Atmp1 ), 32 - QA - lz );  /* Q( -rshifts )*/
            tmp2 = silk_ADD_LSHIFT32( tmp2, silk_SMMUL( C_first_row[ n - k - 1 ], Atmp1 ), 32 - QA - lz );  /* Q( -rshifts )*/
            num  = silk_ADD_LSHIFT32( num,  silk_SMMUL( CAb[ n - k ],             Atmp1 ), 32 - QA - lz );  /* Q( -rshifts )*/
            nrg  = silk_ADD_LSHIFT32( nrg,  silk_SMMUL( silk_ADD32( CAb[ k + 1 ], CAf[ k + 1 ] ),
                                                                                Atmp1 ), 32 - QA - lz );    /* Q( 1-rshifts )*/
        }
        CAf[ n + 1 ] = tmp1;                                                                            /* Q( -rshifts )*/
        CAb[ n + 1 ] = tmp2;                                                                            /* Q( -rshifts )*/
        num = silk_ADD32( num, tmp2 );                                                                  /* Q( -rshifts )*/
        num = silk_LSHIFT32( -num, 1 );                                                                 /* Q( 1-rshifts )*/

        /* Calculate the next order reflection (parcor) coefficient */
        if( silk_abs( num ) < nrg ) {
            rc_Q31 = silk_DIV32_varQ( num, nrg, 31 );
        } else {
            /* Negative energy or ratio too high; set remaining coefficients to zero and exit loop */
            silk_memset( &Af_QA[ n ], 0, ( D - n ) * sizeof( opus_int32 ) );
            silk_assert( 0 );
            break;
        }

        /* Update the AR coefficients */
        for( k = 0; k < (n + 1) >> 1; k++ ) {
            tmp1 = Af_QA[ k ];                                                                  /* QA*/
            tmp2 = Af_QA[ n - k - 1 ];                                                          /* QA*/
            Af_QA[ k ]         = silk_ADD_LSHIFT32( tmp1, silk_SMMUL( tmp2, rc_Q31 ), 1 );      /* QA*/
            Af_QA[ n - k - 1 ] = silk_ADD_LSHIFT32( tmp2, silk_SMMUL( tmp1, rc_Q31 ), 1 );      /* QA*/
        }
        Af_QA[ n ] = silk_RSHIFT32( rc_Q31, 31 - QA );                                          /* QA*/

        /* Update C * Af and C * Ab */
        for( k = 0; k <= n + 1; k++ ) {
            tmp1 = CAf[ k ];                                                                    /* Q( -rshifts )*/
            tmp2 = CAb[ n - k + 1 ];                                                            /* Q( -rshifts )*/
            CAf[ k ]         = silk_ADD_LSHIFT32( tmp1, silk_SMMUL( tmp2, rc_Q31 ), 1 );        /* Q( -rshifts )*/
            CAb[ n - k + 1 ] = silk_ADD_LSHIFT32( tmp2, silk_SMMUL( tmp1, rc_Q31 ), 1 );        /* Q( -rshifts )*/
        }
    }

    /* Return residual energy */
    nrg  = CAf[ 0 ];                                                                            /* Q( -rshifts )*/
    tmp1 = 1 << 16;                                                                             /* Q16*/
    for( k = 0; k < D; k++ ) {
        Atmp1 = silk_RSHIFT_ROUND( Af_QA[ k ], QA - 16 );                                       /* Q16*/
        nrg  = silk_SMLAWW( nrg, CAf[ k + 1 ], Atmp1 );                                         /* Q( -rshifts )*/
        tmp1 = silk_SMLAWW( tmp1, Atmp1, Atmp1 );                                               /* Q16*/
        A_Q16[ k ] = -Atmp1;
    }
    *res_nrg = silk_SMLAWW( nrg, silk_SMMUL( WhiteNoiseFrac_Q32, C0 ), -tmp1 );                 /* Q( -rshifts )*/
    *res_nrg_Q = -rshifts;
}
Exemple #29
0
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    */
    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;
    silk_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 );
        }
        if ( psDec->indices.signalType != TYPE_NO_VOICE_ACTIVITY ) {
            /* 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 ) );

    silk_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 ) ) );
    }

    /* 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;
}
Exemple #30
0
/* Convert Left/Right stereo signal to adaptive Mid/Side representation */
void silk_stereo_LR_to_MS(
    stereo_enc_state            *state,                         /* I/O  State                                       */
    opus_int16                  x1[],                           /* I/O  Left input signal, becomes mid signal       */
    opus_int16                  x2[],                           /* I/O  Right input signal, becomes side signal     */
    opus_int8                   ix[ 2 ][ 3 ],                   /* O    Quantization indices                        */
    opus_int8                   *mid_only_flag,                 /* O    Flag: only mid signal coded                 */
    opus_int32                  mid_side_rates_bps[],           /* O    Bitrates for mid and side signals           */
    opus_int32                  total_rate_bps,                 /* I    Total bitrate                               */
    opus_int                    prev_speech_act_Q8,             /* I    Speech activity level in previous frame     */
    opus_int                    toMono,                         /* I    Last frame before a stereo->mono transition */
    opus_int                    fs_kHz,                         /* I    Sample rate (kHz)                           */
    opus_int                    frame_length                    /* I    Number of samples                           */
)
{
    opus_int   n, is10msFrame, denom_Q16, delta0_Q13, delta1_Q13;
    opus_int32 sum, diff, smooth_coef_Q16, pred_Q13[ 2 ], pred0_Q13, pred1_Q13;
    opus_int32 LP_ratio_Q14, HP_ratio_Q14, frac_Q16, frac_3_Q16, min_mid_rate_bps, width_Q14, w_Q24, deltaw_Q24;
    VARDECL( opus_int16, side );
    VARDECL( opus_int16, LP_mid );
    VARDECL( opus_int16, HP_mid );
    VARDECL( opus_int16, LP_side );
    VARDECL( opus_int16, HP_side );
    opus_int16 *mid = &x1[ -2 ];
    SAVE_STACK;

    ALLOC( side, frame_length + 2, opus_int16 );
    /* Convert to basic mid/side signals */
    for( n = 0; n < frame_length + 2; n++ ) {
        sum  = x1[ n - 2 ] + (opus_int32)x2[ n - 2 ];
        diff = x1[ n - 2 ] - (opus_int32)x2[ n - 2 ];
        mid[  n ] = (opus_int16)silk_RSHIFT_ROUND( sum, 1 );
        side[ n ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( diff, 1 ) );
    }

    /* Buffering */
    silk_memcpy( mid,  state->sMid,  2 * sizeof( opus_int16 ) );
    silk_memcpy( side, state->sSide, 2 * sizeof( opus_int16 ) );
    silk_memcpy( state->sMid,  &mid[  frame_length ], 2 * sizeof( opus_int16 ) );
    silk_memcpy( state->sSide, &side[ frame_length ], 2 * sizeof( opus_int16 ) );

    /* LP and HP filter mid signal */
    ALLOC( LP_mid, frame_length, opus_int16 );
    ALLOC( HP_mid, frame_length, opus_int16 );
    for( n = 0; n < frame_length; n++ ) {
        sum = silk_RSHIFT_ROUND( silk_ADD_LSHIFT( mid[ n ] + mid[ n + 2 ], mid[ n + 1 ], 1 ), 2 );
        LP_mid[ n ] = sum;
        HP_mid[ n ] = mid[ n + 1 ] - sum;
    }

    /* LP and HP filter side signal */
    ALLOC( LP_side, frame_length, opus_int16 );
    ALLOC( HP_side, frame_length, opus_int16 );
    for( n = 0; n < frame_length; n++ ) {
        sum = silk_RSHIFT_ROUND( silk_ADD_LSHIFT( side[ n ] + side[ n + 2 ], side[ n + 1 ], 1 ), 2 );
        LP_side[ n ] = sum;
        HP_side[ n ] = side[ n + 1 ] - sum;
    }

    /* Find energies and predictors */
    is10msFrame = frame_length == 10 * fs_kHz;
    smooth_coef_Q16 = is10msFrame ?
        SILK_FIX_CONST( STEREO_RATIO_SMOOTH_COEF / 2, 16 ) :
        SILK_FIX_CONST( STEREO_RATIO_SMOOTH_COEF,     16 );
    smooth_coef_Q16 = silk_SMULWB( silk_SMULBB( prev_speech_act_Q8, prev_speech_act_Q8 ), smooth_coef_Q16 );

    pred_Q13[ 0 ] = silk_stereo_find_predictor( &LP_ratio_Q14, LP_mid, LP_side, &state->mid_side_amp_Q0[ 0 ], frame_length, smooth_coef_Q16 );
    pred_Q13[ 1 ] = silk_stereo_find_predictor( &HP_ratio_Q14, HP_mid, HP_side, &state->mid_side_amp_Q0[ 2 ], frame_length, smooth_coef_Q16 );
    /* Ratio of the norms of residual and mid signals */
    frac_Q16 = silk_SMLABB( HP_ratio_Q14, LP_ratio_Q14, 3 );
    frac_Q16 = silk_min( frac_Q16, SILK_FIX_CONST( 1, 16 ) );

    /* Determine bitrate distribution between mid and side, and possibly reduce stereo width */
    total_rate_bps -= is10msFrame ? 1200 : 600;      /* Subtract approximate bitrate for coding stereo parameters */
    if( total_rate_bps < 1 ) {
        total_rate_bps = 1;
    }
    min_mid_rate_bps = silk_SMLABB( 2000, fs_kHz, 900 );
    silk_assert( min_mid_rate_bps < 32767 );
    /* Default bitrate distribution: 8 parts for Mid and (5+3*frac) parts for Side. so: mid_rate = ( 8 / ( 13 + 3 * frac ) ) * total_ rate */
    frac_3_Q16 = silk_MUL( 3, frac_Q16 );
    mid_side_rates_bps[ 0 ] = silk_DIV32_varQ( total_rate_bps, SILK_FIX_CONST( 8 + 5, 16 ) + frac_3_Q16, 16+3 );
    /* If Mid bitrate below minimum, reduce stereo width */
    if( mid_side_rates_bps[ 0 ] < min_mid_rate_bps ) {
        mid_side_rates_bps[ 0 ] = min_mid_rate_bps;
        mid_side_rates_bps[ 1 ] = total_rate_bps - mid_side_rates_bps[ 0 ];
        /* width = 4 * ( 2 * side_rate - min_rate ) / ( ( 1 + 3 * frac ) * min_rate ) */
        width_Q14 = silk_DIV32_varQ( silk_LSHIFT( mid_side_rates_bps[ 1 ], 1 ) - min_mid_rate_bps,
            silk_SMULWB( SILK_FIX_CONST( 1, 16 ) + frac_3_Q16, min_mid_rate_bps ), 14+2 );
        width_Q14 = silk_LIMIT( width_Q14, 0, SILK_FIX_CONST( 1, 14 ) );
    } else {
        mid_side_rates_bps[ 1 ] = total_rate_bps - mid_side_rates_bps[ 0 ];
        width_Q14 = SILK_FIX_CONST( 1, 14 );
    }

    /* Smoother */
    state->smth_width_Q14 = (opus_int16)silk_SMLAWB( state->smth_width_Q14, width_Q14 - state->smth_width_Q14, smooth_coef_Q16 );

    /* At very low bitrates or for inputs that are nearly amplitude panned, switch to panned-mono coding */
    *mid_only_flag = 0;
    if( toMono ) {
        /* Last frame before stereo->mono transition; collapse stereo width */
        width_Q14 = 0;
        pred_Q13[ 0 ] = 0;
        pred_Q13[ 1 ] = 0;
        silk_stereo_quant_pred( pred_Q13, ix );
    } else if( state->width_prev_Q14 == 0 &&
        ( 8 * total_rate_bps < 13 * min_mid_rate_bps || silk_SMULWB( frac_Q16, state->smth_width_Q14 ) < SILK_FIX_CONST( 0.05, 14 ) ) )
    {
        /* Code as panned-mono; previous frame already had zero width */
        /* Scale down and quantize predictors */
        pred_Q13[ 0 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 0 ] ), 14 );
        pred_Q13[ 1 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 1 ] ), 14 );
        silk_stereo_quant_pred( pred_Q13, ix );
        /* Collapse stereo width */
        width_Q14 = 0;
        pred_Q13[ 0 ] = 0;
        pred_Q13[ 1 ] = 0;
        mid_side_rates_bps[ 0 ] = total_rate_bps;
        mid_side_rates_bps[ 1 ] = 0;
        *mid_only_flag = 1;
    } else if( state->width_prev_Q14 != 0 &&
        ( 8 * total_rate_bps < 11 * min_mid_rate_bps || silk_SMULWB( frac_Q16, state->smth_width_Q14 ) < SILK_FIX_CONST( 0.02, 14 ) ) )
    {
        /* Transition to zero-width stereo */
        /* Scale down and quantize predictors */
        pred_Q13[ 0 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 0 ] ), 14 );
        pred_Q13[ 1 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 1 ] ), 14 );
        silk_stereo_quant_pred( pred_Q13, ix );
        /* Collapse stereo width */
        width_Q14 = 0;
        pred_Q13[ 0 ] = 0;
        pred_Q13[ 1 ] = 0;
    } else if( state->smth_width_Q14 > SILK_FIX_CONST( 0.95, 14 ) ) {
        /* Full-width stereo coding */
        silk_stereo_quant_pred( pred_Q13, ix );
        width_Q14 = SILK_FIX_CONST( 1, 14 );
    } else {
        /* Reduced-width stereo coding; scale down and quantize predictors */
        pred_Q13[ 0 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 0 ] ), 14 );
        pred_Q13[ 1 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 1 ] ), 14 );
        silk_stereo_quant_pred( pred_Q13, ix );
        width_Q14 = state->smth_width_Q14;
    }

    /* Make sure to keep on encoding until the tapered output has been transmitted */
    if( *mid_only_flag == 1 ) {
        state->silent_side_len += frame_length - STEREO_INTERP_LEN_MS * fs_kHz;
        if( state->silent_side_len < LA_SHAPE_MS * fs_kHz ) {
            *mid_only_flag = 0;
        } else {
            /* Limit to avoid wrapping around */
            state->silent_side_len = 10000;
        }
    } else {
        state->silent_side_len = 0;
    }

    if( *mid_only_flag == 0 && mid_side_rates_bps[ 1 ] < 1 ) {
        mid_side_rates_bps[ 1 ] = 1;
        mid_side_rates_bps[ 0 ] = silk_max_int( 1, total_rate_bps - mid_side_rates_bps[ 1 ]);
    }

    /* Interpolate predictors and subtract prediction from side channel */
    pred0_Q13  = -state->pred_prev_Q13[ 0 ];
    pred1_Q13  = -state->pred_prev_Q13[ 1 ];
    w_Q24      =  silk_LSHIFT( state->width_prev_Q14, 10 );
    denom_Q16  = silk_DIV32_16( (opus_int32)1 << 16, STEREO_INTERP_LEN_MS * fs_kHz );
    delta0_Q13 = -silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 0 ] - state->pred_prev_Q13[ 0 ], denom_Q16 ), 16 );
    delta1_Q13 = -silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 1 ] - state->pred_prev_Q13[ 1 ], denom_Q16 ), 16 );
    deltaw_Q24 =  silk_LSHIFT( silk_SMULWB( width_Q14 - state->width_prev_Q14, denom_Q16 ), 10 );
    for( n = 0; n < STEREO_INTERP_LEN_MS * fs_kHz; n++ ) {
        pred0_Q13 += delta0_Q13;
        pred1_Q13 += delta1_Q13;
        w_Q24   += deltaw_Q24;
        sum = silk_LSHIFT( silk_ADD_LSHIFT( mid[ n ] + mid[ n + 2 ], mid[ n + 1 ], 1 ), 9 );    /* Q11 */
        sum = silk_SMLAWB( silk_SMULWB( w_Q24, side[ n + 1 ] ), sum, pred0_Q13 );               /* Q8  */
        sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)mid[ n + 1 ], 11 ), pred1_Q13 );       /* Q8  */
        x2[ n - 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) );
    }

    pred0_Q13 = -pred_Q13[ 0 ];
    pred1_Q13 = -pred_Q13[ 1 ];
    w_Q24     =  silk_LSHIFT( width_Q14, 10 );
    for( n = STEREO_INTERP_LEN_MS * fs_kHz; n < frame_length; n++ ) {
        sum = silk_LSHIFT( silk_ADD_LSHIFT( mid[ n ] + mid[ n + 2 ], mid[ n + 1 ], 1 ), 9 );    /* Q11 */
        sum = silk_SMLAWB( silk_SMULWB( w_Q24, side[ n + 1 ] ), sum, pred0_Q13 );               /* Q8  */
        sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)mid[ n + 1 ], 11 ), pred1_Q13 );       /* Q8  */
        x2[ n - 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) );
    }
    state->pred_prev_Q13[ 0 ] = (opus_int16)pred_Q13[ 0 ];
    state->pred_prev_Q13[ 1 ] = (opus_int16)pred_Q13[ 1 ];
    state->width_prev_Q14     = (opus_int16)width_Q14;
    RESTORE_STACK;
}