59 lines
3.3 KiB
C
59 lines
3.3 KiB
C
/***********************************************************************
|
|
Copyright (c) 2006-2011, Skype Limited. All rights reserved.
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, (subject to the limitations in the disclaimer below)
|
|
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 Skype Limited, nor the names of specific
|
|
contributors, may be used to endorse or promote products derived from
|
|
this software without specific prior written permission.
|
|
NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED
|
|
BY THIS LICENSE. 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.
|
|
***********************************************************************/
|
|
|
|
/* *
|
|
* SKP_Silk_k2a.c *
|
|
* *
|
|
* Step up function, converts reflection coefficients to prediction *
|
|
* coefficients *
|
|
* *
|
|
* Copyright 2008 (c), Skype Limited *
|
|
* Date: 080103 *
|
|
* */
|
|
#include "SKP_Silk_SigProc_FIX.h"
|
|
|
|
/* Step up function, converts reflection coefficients to prediction coefficients */
|
|
void SKP_Silk_k2a(
|
|
SKP_int32 *A_Q24, /* O: Prediction coefficients [order] Q24 */
|
|
const SKP_int16 *rc_Q15, /* I: Reflection coefficients [order] Q15 */
|
|
const SKP_int32 order /* I: Prediction order */
|
|
)
|
|
{
|
|
SKP_int k, n;
|
|
SKP_int32 Atmp[ SKP_Silk_MAX_ORDER_LPC ];
|
|
|
|
for( k = 0; k < order; k++ ) {
|
|
for( n = 0; n < k; n++ ) {
|
|
Atmp[ n ] = A_Q24[ n ];
|
|
}
|
|
for( n = 0; n < k; n++ ) {
|
|
A_Q24[ n ] = SKP_SMLAWB( A_Q24[ n ], SKP_LSHIFT( Atmp[ k - n - 1 ], 1 ), rc_Q15[ k ] );
|
|
}
|
|
A_Q24[ k ] = -SKP_LSHIFT( (SKP_int32)rc_Q15[ k ], 9 );
|
|
}
|
|
}
|