/* Find least-squares prediction gain for one signal based on another and quantize it */
int32_t silk_stereo_find_predictor(	/* O    Returns predictor in Q13                    */
					     int32_t * ratio_Q14,	/* O    Ratio of residual and mid energies          */
					     const int16_t x[],	/* I    Basis signal                                */
					     const int16_t y[],	/* I    Target signal                               */
					     int32_t mid_res_amp_Q0[],	/* I/O  Smoothed mid, residual norms                */
					     int length,	/* I    Number of samples                           */
					     int smooth_coef_Q16	/* I    Smoothing coefficient                       */
    )
{
	int scale, scale1, scale2;
	int32_t nrgx, nrgy, corr, pred_Q13, pred2_Q10;

	/* Find  predictor */
	silk_sum_sqr_shift(&nrgx, &scale1, x, length);
	silk_sum_sqr_shift(&nrgy, &scale2, y, length);
	scale = silk_max_int(scale1, scale2);
	scale = scale + (scale & 1);	/* make even */
	nrgy = silk_RSHIFT32(nrgy, scale - scale2);
	nrgx = silk_RSHIFT32(nrgx, scale - scale1);
	nrgx = silk_max_int(nrgx, 1);
	corr = silk_inner_prod_aligned_scale(x, y, scale, length);
	pred_Q13 = silk_DIV32_varQ(corr, nrgx, 13);
	pred_Q13 = silk_LIMIT(pred_Q13, -(1 << 14), 1 << 14);
	pred2_Q10 = silk_SMULWB(pred_Q13, pred_Q13);

	/* Faster update for signals with large prediction parameters */
	smooth_coef_Q16 =
	    (int) silk_max_int(smooth_coef_Q16, silk_abs(pred2_Q10));

	/* Smoothed mid and residual norms */
	assert(smooth_coef_Q16 < 32768);
	scale = silk_RSHIFT(scale, 1);
	mid_res_amp_Q0[0] =
	    silk_SMLAWB(mid_res_amp_Q0[0],
			silk_LSHIFT(silk_SQRT_APPROX(nrgx),
				    scale) - mid_res_amp_Q0[0],
			smooth_coef_Q16);
	/* Residual energy = nrgy - 2 * pred * corr + pred^2 * nrgx */
	nrgy = silk_SUB_LSHIFT32(nrgy, silk_SMULWB(corr, pred_Q13), 3 + 1);
	nrgy = silk_ADD_LSHIFT32(nrgy, silk_SMULWB(nrgx, pred2_Q10), 6);
	mid_res_amp_Q0[1] =
	    silk_SMLAWB(mid_res_amp_Q0[1],
			silk_LSHIFT(silk_SQRT_APPROX(nrgy),
				    scale) - mid_res_amp_Q0[1],
			smooth_coef_Q16);

	/* Ratio of smoothed residual and mid norms */
	*ratio_Q14 =
	    silk_DIV32_varQ(mid_res_amp_Q0[1], silk_max(mid_res_amp_Q0[0], 1),
			    14);
	*ratio_Q14 = silk_LIMIT(*ratio_Q14, 0, 32767);

	return pred_Q13;
}
Exemple #2
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/* Calculates correlation vector X'*t */
void silk_corrVector_FIX(
    const opus_int16                *x,                                     /* I    x vector [L + order - 1] used to form data matrix X                         */
    const opus_int16                *t,                                     /* I    Target vector [L]                                                           */
    const opus_int                  L,                                      /* I    Length of vectors                                                           */
    const opus_int                  order,                                  /* I    Max lag for correlation                                                     */
    opus_int32                      *Xt,                                    /* O    Pointer to X'*t correlation vector [order]                                  */
    const opus_int                  rshifts                                 /* I    Right shifts of correlations                                                */
)
{
    opus_int         lag, i;
    const opus_int16 *ptr1, *ptr2;
    opus_int32       inner_prod;

    ptr1 = &x[ order - 1 ]; /* Points to first sample of column 0 of X: X[:,0] */
    ptr2 = t;
    /* Calculate X'*t */
    if( rshifts > 0 ) {
        /* Right shifting used */
        for( lag = 0; lag < order; lag++ ) {
            inner_prod = 0;
            for( i = 0; i < L; i++ ) {
                inner_prod += silk_RSHIFT32( silk_SMULBB( ptr1[ i ], ptr2[i] ), rshifts );
            }
            Xt[ lag ] = inner_prod; /* X[:,lag]'*t */
            ptr1--; /* Go to next column of X */
        }
    } else {
        silk_assert( rshifts == 0 );
        for( lag = 0; lag < order; lag++ ) {
            Xt[ lag ] = silk_inner_prod_aligned( ptr1, ptr2, L ); /* X[:,lag]'*t */
            ptr1--; /* Go to next column of X */
        }
    }
}
/* For input in Q24 domain */
opus_int32 silk_LPC_inverse_pred_gain_Q24(          /* O    Returns inverse prediction gain in energy domain, Q30       */
    const opus_int32            *A_Q24,             /* I    Prediction coefficients [order]                             */
    const opus_int              order               /* I    Prediction order                                            */
)
{
    opus_int   k;
    opus_int32 Atmp_QA[ SILK_MAX_ORDER_LPC ];

    /* Increase Q domain of the AR coefficients */
    for( k = 0; k < order; k++ ) {
        Atmp_QA[ k ] = silk_RSHIFT32( A_Q24[ k ], 24 - QA );
    }

    return LPC_inverse_pred_gain_QA( Atmp_QA, order );
}
/* 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 );
        }
    }
}
/* For input in Q24 domain */
int32_t silk_LPC_inverse_pred_gain_Q24(	/* O    Returns inverse prediction gain in energy domain, Q30       */
						 const int32_t * A_Q24,	/* I    Prediction coefficients [order]                             */
						 const int order	/* I    Prediction order                                            */
    )
{
	int k;
	int32_t Atmp_QA[2][SILK_MAX_ORDER_LPC];
	int32_t *Anew_QA;

	memzero(Atmp_QA, (2 * SILK_MAX_ORDER_LPC) * sizeof(int32_t));

	Anew_QA = Atmp_QA[order & 1];

	/* Increase Q domain of the AR coefficients */
	for (k = 0; k < order; k++) {
		Anew_QA[k] = silk_RSHIFT32(A_Q24[k], 24 - QA);
	}

	return LPC_inverse_pred_gain_QA(Atmp_QA, order);
}
Exemple #6
0
/* Calculates correlation matrix X'*X */
void silk_corrMatrix_FIX(
    const opus_int16                *x,                                     /* I    x vector [L + order - 1] used to form data matrix X                         */
    const opus_int                  L,                                      /* I    Length of vectors                                                           */
    const opus_int                  order,                                  /* I    Max lag for correlation                                                     */
    const opus_int                  head_room,                              /* I    Desired headroom                                                            */
    opus_int32                      *XX,                                    /* O    Pointer to X'*X correlation matrix [ order x order ]                        */
    opus_int                        *rshifts                                /* I/O  Right shifts of correlations                                                */
)
{
    opus_int         i, j, lag, rshifts_local, head_room_rshifts;
    opus_int32       energy;
    const opus_int16 *ptr1, *ptr2;

    /* Calculate energy to find shift used to fit in 32 bits */
    silk_sum_sqr_shift( &energy, &rshifts_local, x, L + order - 1 );
    /* Add shifts to get the desired head room */
    head_room_rshifts = silk_max( head_room - silk_CLZ32( energy ), 0 );

    energy = silk_RSHIFT32( energy, head_room_rshifts );
    rshifts_local += head_room_rshifts;

    /* Calculate energy of first column (0) of X: X[:,0]'*X[:,0] */
    /* Remove contribution of first order - 1 samples */
    for( i = 0; i < order - 1; i++ ) {
        energy -= silk_RSHIFT32( silk_SMULBB( x[ i ], x[ i ] ), rshifts_local );
    }
    if( rshifts_local < *rshifts ) {
        /* Adjust energy */
        energy = silk_RSHIFT32( energy, *rshifts - rshifts_local );
        rshifts_local = *rshifts;
    }

    /* Calculate energy of remaining columns of X: X[:,j]'*X[:,j] */
    /* Fill out the diagonal of the correlation matrix */
    matrix_ptr( XX, 0, 0, order ) = energy;
    ptr1 = &x[ order - 1 ]; /* First sample of column 0 of X */
    for( j = 1; j < order; j++ ) {
        energy = silk_SUB32( energy, silk_RSHIFT32( silk_SMULBB( ptr1[ L - j ], ptr1[ L - j ] ), rshifts_local ) );
        energy = silk_ADD32( energy, silk_RSHIFT32( silk_SMULBB( ptr1[ -j ], ptr1[ -j ] ), rshifts_local ) );
        matrix_ptr( XX, j, j, order ) = energy;
    }

    ptr2 = &x[ order - 2 ]; /* First sample of column 1 of X */
    /* Calculate the remaining elements of the correlation matrix */
    if( rshifts_local > 0 ) {
        /* Right shifting used */
        for( lag = 1; lag < order; lag++ ) {
            /* Inner product of column 0 and column lag: X[:,0]'*X[:,lag] */
            energy = 0;
            for( i = 0; i < L; i++ ) {
                energy += silk_RSHIFT32( silk_SMULBB( ptr1[ i ], ptr2[i] ), rshifts_local );
            }
            /* Calculate remaining off diagonal: X[:,j]'*X[:,j + lag] */
            matrix_ptr( XX, lag, 0, order ) = energy;
            matrix_ptr( XX, 0, lag, order ) = energy;
            for( j = 1; j < ( order - lag ); j++ ) {
                energy = silk_SUB32( energy, silk_RSHIFT32( silk_SMULBB( ptr1[ L - j ], ptr2[ L - j ] ), rshifts_local ) );
                energy = silk_ADD32( energy, silk_RSHIFT32( silk_SMULBB( ptr1[ -j ], ptr2[ -j ] ), rshifts_local ) );
                matrix_ptr( XX, lag + j, j, order ) = energy;
                matrix_ptr( XX, j, lag + j, order ) = energy;
            }
            ptr2--; /* Update pointer to first sample of next column (lag) in X */
        }
    } else {
        for( lag = 1; lag < order; lag++ ) {
            /* Inner product of column 0 and column lag: X[:,0]'*X[:,lag] */
            energy = silk_inner_prod_aligned( ptr1, ptr2, L );
            matrix_ptr( XX, lag, 0, order ) = energy;
            matrix_ptr( XX, 0, lag, order ) = energy;
            /* Calculate remaining off diagonal: X[:,j]'*X[:,j + lag] */
            for( j = 1; j < ( order - lag ); j++ ) {
                energy = silk_SUB32( energy, silk_SMULBB( ptr1[ L - j ], ptr2[ L - j ] ) );
                energy = silk_SMLABB( energy, ptr1[ -j ], ptr2[ -j ] );
                matrix_ptr( XX, lag + j, j, order ) = energy;
                matrix_ptr( XX, j, lag + j, order ) = energy;
            }
            ptr2--;/* Update pointer to first sample of next column (lag) in X */
        }
    }
    *rshifts = rshifts_local;
}
/* 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 #8
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;
        }
    }
}
/* 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;
    }
}
/* 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;
    }   
}
Exemple #11
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;
}
void silk_find_LTP_FIX(
    opus_int32                      XXLTP_Q17[ MAX_NB_SUBFR * LTP_ORDER * LTP_ORDER ], /* O    Correlation matrix                                               */
    opus_int32                      xXLTP_Q17[ MAX_NB_SUBFR * LTP_ORDER ],  /* O    Correlation vector                                                          */
    const opus_int16                r_ptr[],                                /* I    Residual signal after LPC                                                   */
    const opus_int                  lag[ MAX_NB_SUBFR ],                    /* I    LTP lags                                                                    */
    const opus_int                  subfr_length,                           /* I    Subframe length                                                             */
    const opus_int                  nb_subfr,                               /* I    Number of subframes                                                         */
    int                             arch                                    /* I    Run-time architecture                                                       */
)
{
    opus_int   i, k, extra_shifts;
    opus_int   xx_shifts, xX_shifts, XX_shifts;
    const opus_int16 *lag_ptr;
    opus_int32 *XXLTP_Q17_ptr, *xXLTP_Q17_ptr;
    opus_int32 xx, nrg, temp;

    xXLTP_Q17_ptr = xXLTP_Q17;
    XXLTP_Q17_ptr = XXLTP_Q17;
    for( k = 0; k < nb_subfr; k++ ) {
        lag_ptr = r_ptr - ( lag[ k ] + LTP_ORDER / 2 );

        silk_sum_sqr_shift( &xx, &xx_shifts, r_ptr, subfr_length + LTP_ORDER );                            /* xx in Q( -xx_shifts ) */
        silk_corrMatrix_FIX( lag_ptr, subfr_length, LTP_ORDER, XXLTP_Q17_ptr, &nrg, &XX_shifts, arch );    /* XXLTP_Q17_ptr and nrg in Q( -XX_shifts ) */
        extra_shifts = xx_shifts - XX_shifts;
        if( extra_shifts > 0 ) {
            /* Shift XX */
            xX_shifts = xx_shifts;
            for( i = 0; i < LTP_ORDER * LTP_ORDER; i++ ) {
                XXLTP_Q17_ptr[ i ] = silk_RSHIFT32( XXLTP_Q17_ptr[ i ], extra_shifts );              /* Q( -xX_shifts ) */
            }
            nrg = silk_RSHIFT32( nrg, extra_shifts );                                                /* Q( -xX_shifts ) */
        } else if( extra_shifts < 0 ) {
            /* Shift xx */
            xX_shifts = XX_shifts;
            xx = silk_RSHIFT32( xx, -extra_shifts );                                                 /* Q( -xX_shifts ) */
        } else {
            xX_shifts = xx_shifts;
        }
        silk_corrVector_FIX( lag_ptr, r_ptr, subfr_length, LTP_ORDER, xXLTP_Q17_ptr, xX_shifts, arch );    /* xXLTP_Q17_ptr in Q( -xX_shifts ) */

        /* At this point all correlations are in Q(-xX_shifts) */
        temp = silk_SMLAWB( 1, nrg, SILK_FIX_CONST( LTP_CORR_INV_MAX, 16 ) );
        temp = silk_max( temp, xx );
TIC(div)
#if 0
        for( i = 0; i < LTP_ORDER * LTP_ORDER; i++ ) {
            XXLTP_Q17_ptr[ i ] = silk_DIV32_varQ( XXLTP_Q17_ptr[ i ], temp, 17 );
        }
        for( i = 0; i < LTP_ORDER; i++ ) {
            xXLTP_Q17_ptr[ i ] = silk_DIV32_varQ( xXLTP_Q17_ptr[ i ], temp, 17 );
        }
#else
        for( i = 0; i < LTP_ORDER * LTP_ORDER; i++ ) {
            XXLTP_Q17_ptr[ i ] = (opus_int32)( silk_LSHIFT64( (opus_int64)XXLTP_Q17_ptr[ i ], 17 ) / temp );
        }
        for( i = 0; i < LTP_ORDER; i++ ) {
            xXLTP_Q17_ptr[ i ] = (opus_int32)( silk_LSHIFT64( (opus_int64)xXLTP_Q17_ptr[ i ], 17 ) / temp );
        }
#endif
TOC(div)
        r_ptr         += subfr_length;
        XXLTP_Q17_ptr += LTP_ORDER * LTP_ORDER;
        xXLTP_Q17_ptr += LTP_ORDER;
    }
}