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| author | Jean-Marc Valin <jean-marc.valin@octasic.com> | 2011-04-28 15:51:30 -0400 |
|---|---|---|
| committer | Jean-Marc Valin <jean-marc.valin@octasic.com> | 2011-04-28 15:51:30 -0400 |
| commit | 011402a252450a6883f109a86e5dd7e24aa0d3a0 (patch) | |
| tree | ca0ccc793038464aeb1031918683ab4f1c67ecec /src_SigProc_FIX/SKP_Silk_autocorr.c | |
| parent | 93839b636d0a1801950bf1ddf52e52cc12b6391a (diff) | |
| parent | 7d50a792c1a90425e1972a1cfea2d0d61416297b (diff) | |
| download | opus-011402a252450a6883f109a86e5dd7e24aa0d3a0.tar.gz | |
Merge commit 'silk-repo/master'
Diffstat (limited to 'src_SigProc_FIX/SKP_Silk_autocorr.c')
| -rw-r--r-- | src_SigProc_FIX/SKP_Silk_autocorr.c | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/src_SigProc_FIX/SKP_Silk_autocorr.c b/src_SigProc_FIX/SKP_Silk_autocorr.c new file mode 100644 index 00000000..c7f8b292 --- /dev/null +++ b/src_SigProc_FIX/SKP_Silk_autocorr.c @@ -0,0 +1,72 @@ +/***********************************************************************
+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.
+***********************************************************************/
+
+#include "SKP_Silk_SigProc_FIX.h"
+
+/* Compute autocorrelation */
+void SKP_Silk_autocorr(
+ SKP_int32 *results, /* O Result (length correlationCount) */
+ SKP_int *scale, /* O Scaling of the correlation vector */
+ const SKP_int16 *inputData, /* I Input data to correlate */
+ const SKP_int inputDataSize, /* I Length of input */
+ const SKP_int correlationCount /* I Number of correlation taps to compute */
+)
+{
+ SKP_int i, lz, nRightShifts, corrCount;
+ SKP_int64 corr64;
+
+ corrCount = SKP_min_int( inputDataSize, correlationCount );
+
+ /* compute energy (zero-lag correlation) */
+ corr64 = SKP_Silk_inner_prod16_aligned_64( inputData, inputData, inputDataSize );
+
+ /* deal with all-zero input data */
+ corr64 += 1;
+
+ /* number of leading zeros */
+ lz = SKP_Silk_CLZ64( corr64 );
+
+ /* scaling: number of right shifts applied to correlations */
+ nRightShifts = 35 - lz;
+ *scale = nRightShifts;
+
+ if( nRightShifts <= 0 ) {
+ results[ 0 ] = SKP_LSHIFT( (SKP_int32)SKP_CHECK_FIT32( corr64 ), -nRightShifts );
+
+ /* compute remaining correlations based on int32 inner product */
+ for( i = 1; i < corrCount; i++ ) {
+ results[ i ] = SKP_LSHIFT( SKP_Silk_inner_prod_aligned( inputData, inputData + i, inputDataSize - i ), -nRightShifts );
+ }
+ } else {
+ results[ 0 ] = (SKP_int32)SKP_CHECK_FIT32( SKP_RSHIFT64( corr64, nRightShifts ) );
+
+ /* compute remaining correlations based on int64 inner product */
+ for( i = 1; i < corrCount; i++ ) {
+ results[ i ] = (SKP_int32)SKP_CHECK_FIT32( SKP_RSHIFT64( SKP_Silk_inner_prod16_aligned_64( inputData, inputData + i, inputDataSize - i ), nRightShifts ) );
+ }
+ }
+}
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