shithub: opus

ref: ddd0d21442631f3f67d4e69edad4911bd45449d1
dir: /silk/fixed/corrMatrix_FIX.c/

View raw version
/***********************************************************************
Copyright (c) 2006-2011, Skype Limited. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
- Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
- Neither the name of Internet Society, IETF or IETF Trust, nor the 
names of specific contributors, may be used to endorse or promote
products derived from this software without specific prior written
permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS”
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
***********************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

/**********************************************************************
 * Correlation Matrix Computations for LS estimate.
 **********************************************************************/

#include "main_FIX.h"

/* 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 */
        }
    }
}

/* 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;
}