73 lines
3.5 KiB
C
73 lines
3.5 KiB
C
/***********************************************************************
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Copyright (c) 2006-2011, Skype Limited. All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, (subject to the limitations in the disclaimer below)
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are permitted provided that the following conditions are met:
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- Redistributions of source code must retain the above copyright notice,
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this list of conditions and the following disclaimer.
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- Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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- Neither the name of Skype Limited, nor the names of specific
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contributors, may be used to endorse or promote products derived from
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this software without specific prior written permission.
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NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED
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BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
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CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
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BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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***********************************************************************/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include "main_FLP.h"
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/* Autocorrelations for a warped frequency axis */
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void silk_warped_autocorrelation_FLP(
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silk_float *corr, /* O Result [order + 1] */
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const silk_float *input, /* I Input data to correlate */
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const silk_float warping, /* I Warping coefficient */
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const opus_int length, /* I Length of input */
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const opus_int order /* I Correlation order (even) */
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)
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{
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opus_int n, i;
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double tmp1, tmp2;
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double state[ MAX_SHAPE_LPC_ORDER + 1 ] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };
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double C[ MAX_SHAPE_LPC_ORDER + 1 ] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };
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/* Order must be even */
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silk_assert( ( order & 1 ) == 0 );
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/* Loop over samples */
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for( n = 0; n < length; n++ ) {
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tmp1 = input[ n ];
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/* Loop over allpass sections */
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for( i = 0; i < order; i += 2 ) {
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/* Output of allpass section */
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tmp2 = state[ i ] + warping * ( state[ i + 1 ] - tmp1 );
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state[ i ] = tmp1;
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C[ i ] += state[ 0 ] * tmp1;
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/* Output of allpass section */
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tmp1 = state[ i + 1 ] + warping * ( state[ i + 2 ] - tmp2 );
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state[ i + 1 ] = tmp2;
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C[ i + 1 ] += state[ 0 ] * tmp2;
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}
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state[ order ] = tmp1;
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C[ order ] += state[ 0 ] * tmp1;
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}
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/* Copy correlations in silk_float output format */
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for( i = 0; i < order + 1; i++ ) {
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corr[ i ] = ( silk_float )C[ i ];
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}
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}
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