michael@0: /***********************************************************************
michael@0: Copyright (c) 2006-2011, Skype Limited. All rights reserved.
michael@0: Redistribution and use in source and binary forms, with or without
michael@0: modification, are permitted provided that the following conditions
michael@0: are met:
michael@0: - Redistributions of source code must retain the above copyright notice,
michael@0: this list of conditions and the following disclaimer.
michael@0: - Redistributions in binary form must reproduce the above copyright
michael@0: notice, this list of conditions and the following disclaimer in the
michael@0: documentation and/or other materials provided with the distribution.
michael@0: - Neither the name of Internet Society, IETF or IETF Trust, nor the
michael@0: names of specific contributors, may be used to endorse or promote
michael@0: products derived from this software without specific prior written
michael@0: permission.
michael@0: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
michael@0: AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
michael@0: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
michael@0: ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
michael@0: LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
michael@0: CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
michael@0: SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
michael@0: INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
michael@0: CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
michael@0: ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
michael@0: POSSIBILITY OF SUCH DAMAGE.
michael@0: ***********************************************************************/
michael@0: 
michael@0: #ifdef HAVE_CONFIG_H
michael@0: #include "config.h"
michael@0: #endif
michael@0: 
michael@0: #include "main_FIX.h"
michael@0: 
michael@0: /* Residual energy: nrg = wxx - 2 * wXx * c + c' * wXX * c */
michael@0: opus_int32 silk_residual_energy16_covar_FIX(
michael@0:     const opus_int16                *c,                                     /* I    Prediction vector                                                           */
michael@0:     const opus_int32                *wXX,                                   /* I    Correlation matrix                                                          */
michael@0:     const opus_int32                *wXx,                                   /* I    Correlation vector                                                          */
michael@0:     opus_int32                      wxx,                                    /* I    Signal energy                                                               */
michael@0:     opus_int                        D,                                      /* I    Dimension                                                                   */
michael@0:     opus_int                        cQ                                      /* I    Q value for c vector 0 - 15                                                 */
michael@0: )
michael@0: {
michael@0:     opus_int   i, j, lshifts, Qxtra;
michael@0:     opus_int32 c_max, w_max, tmp, tmp2, nrg;
michael@0:     opus_int   cn[ MAX_MATRIX_SIZE ];
michael@0:     const opus_int32 *pRow;
michael@0: 
michael@0:     /* Safety checks */
michael@0:     silk_assert( D >=  0 );
michael@0:     silk_assert( D <= 16 );
michael@0:     silk_assert( cQ >  0 );
michael@0:     silk_assert( cQ < 16 );
michael@0: 
michael@0:     lshifts = 16 - cQ;
michael@0:     Qxtra = lshifts;
michael@0: 
michael@0:     c_max = 0;
michael@0:     for( i = 0; i < D; i++ ) {
michael@0:         c_max = silk_max_32( c_max, silk_abs( (opus_int32)c[ i ] ) );
michael@0:     }
michael@0:     Qxtra = silk_min_int( Qxtra, silk_CLZ32( c_max ) - 17 );
michael@0: 
michael@0:     w_max = silk_max_32( wXX[ 0 ], wXX[ D * D - 1 ] );
michael@0:     Qxtra = silk_min_int( Qxtra, silk_CLZ32( silk_MUL( D, silk_RSHIFT( silk_SMULWB( w_max, c_max ), 4 ) ) ) - 5 );
michael@0:     Qxtra = silk_max_int( Qxtra, 0 );
michael@0:     for( i = 0; i < D; i++ ) {
michael@0:         cn[ i ] = silk_LSHIFT( ( opus_int )c[ i ], Qxtra );
michael@0:         silk_assert( silk_abs(cn[i]) <= ( silk_int16_MAX + 1 ) ); /* Check that silk_SMLAWB can be used */
michael@0:     }
michael@0:     lshifts -= Qxtra;
michael@0: 
michael@0:     /* Compute wxx - 2 * wXx * c */
michael@0:     tmp = 0;
michael@0:     for( i = 0; i < D; i++ ) {
michael@0:         tmp = silk_SMLAWB( tmp, wXx[ i ], cn[ i ] );
michael@0:     }
michael@0:     nrg = silk_RSHIFT( wxx, 1 + lshifts ) - tmp;                         /* Q: -lshifts - 1 */
michael@0: 
michael@0:     /* Add c' * wXX * c, assuming wXX is symmetric */
michael@0:     tmp2 = 0;
michael@0:     for( i = 0; i < D; i++ ) {
michael@0:         tmp = 0;
michael@0:         pRow = &wXX[ i * D ];
michael@0:         for( j = i + 1; j < D; j++ ) {
michael@0:             tmp = silk_SMLAWB( tmp, pRow[ j ], cn[ j ] );
michael@0:         }
michael@0:         tmp  = silk_SMLAWB( tmp,  silk_RSHIFT( pRow[ i ], 1 ), cn[ i ] );
michael@0:         tmp2 = silk_SMLAWB( tmp2, tmp,                        cn[ i ] );
michael@0:     }
michael@0:     nrg = silk_ADD_LSHIFT32( nrg, tmp2, lshifts );                       /* Q: -lshifts - 1 */
michael@0: 
michael@0:     /* Keep one bit free always, because we add them for LSF interpolation */
michael@0:     if( nrg < 1 ) {
michael@0:         nrg = 1;
michael@0:     } else if( nrg > silk_RSHIFT( silk_int32_MAX, lshifts + 2 ) ) {
michael@0:         nrg = silk_int32_MAX >> 1;
michael@0:     } else {
michael@0:         nrg = silk_LSHIFT( nrg, lshifts + 1 );                           /* Q0 */
michael@0:     }
michael@0:     return nrg;
michael@0: 
michael@0: }