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 "SigProc_FLP.h"
michael@0: 
michael@0: /* step up function, converts reflection coefficients to prediction coefficients */
michael@0: void silk_k2a_FLP(
michael@0:     silk_float          *A,                 /* O     prediction coefficients [order]                            */
michael@0:     const silk_float    *rc,                /* I     reflection coefficients [order]                            */
michael@0:     opus_int32          order               /* I     prediction order                                           */
michael@0: )
michael@0: {
michael@0:     opus_int   k, n;
michael@0:     silk_float Atmp[ SILK_MAX_ORDER_LPC ];
michael@0: 
michael@0:     for( k = 0; k < order; k++ ) {
michael@0:         for( n = 0; n < k; n++ ) {
michael@0:             Atmp[ n ] = A[ n ];
michael@0:         }
michael@0:         for( n = 0; n < k; n++ ) {
michael@0:             A[ n ] += Atmp[ k - n - 1 ] * rc[ k ];
michael@0:         }
michael@0:         A[ k ] = -rc[ k ];
michael@0:     }
michael@0: }