mirror of
https://github.com/UberGames/ioef.git
synced 2024-12-03 17:43:13 +00:00
76 lines
3.6 KiB
C
76 lines
3.6 KiB
C
/***********************************************************************
|
|
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
|
|
|
|
#include "SigProc_FIX.h"
|
|
|
|
/* Compute autocorrelation */
|
|
void silk_autocorr(
|
|
opus_int32 *results, /* O Result (length correlationCount) */
|
|
opus_int *scale, /* O Scaling of the correlation vector */
|
|
const opus_int16 *inputData, /* I Input data to correlate */
|
|
const opus_int inputDataSize, /* I Length of input */
|
|
const opus_int correlationCount /* I Number of correlation taps to compute */
|
|
)
|
|
{
|
|
opus_int i, lz, nRightShifts, corrCount;
|
|
opus_int64 corr64;
|
|
|
|
corrCount = silk_min_int( inputDataSize, correlationCount );
|
|
|
|
/* compute energy (zero-lag correlation) */
|
|
corr64 = silk_inner_prod16_aligned_64( inputData, inputData, inputDataSize );
|
|
|
|
/* deal with all-zero input data */
|
|
corr64 += 1;
|
|
|
|
/* number of leading zeros */
|
|
lz = silk_CLZ64( corr64 );
|
|
|
|
/* scaling: number of right shifts applied to correlations */
|
|
nRightShifts = 35 - lz;
|
|
*scale = nRightShifts;
|
|
|
|
if( nRightShifts <= 0 ) {
|
|
results[ 0 ] = silk_LSHIFT( (opus_int32)silk_CHECK_FIT32( corr64 ), -nRightShifts );
|
|
|
|
/* compute remaining correlations based on int32 inner product */
|
|
for( i = 1; i < corrCount; i++ ) {
|
|
results[ i ] = silk_LSHIFT( silk_inner_prod_aligned( inputData, inputData + i, inputDataSize - i ), -nRightShifts );
|
|
}
|
|
} else {
|
|
results[ 0 ] = (opus_int32)silk_CHECK_FIT32( silk_RSHIFT64( corr64, nRightShifts ) );
|
|
|
|
/* compute remaining correlations based on int64 inner product */
|
|
for( i = 1; i < corrCount; i++ ) {
|
|
results[ i ] = (opus_int32)silk_CHECK_FIT32( silk_RSHIFT64( silk_inner_prod16_aligned_64( inputData, inputData + i, inputDataSize - i ), nRightShifts ) );
|
|
}
|
|
}
|
|
}
|