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/*
* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
/******************************************************************
iLBC Speech Coder ANSI-C Source Code
WebRtcIlbcfix_AugmentedCbCorr.c
******************************************************************/
#include "modules/audio_coding/codecs/ilbc/defines.h"
#include "modules/audio_coding/codecs/ilbc/constants.h"
#include "modules/audio_coding/codecs/ilbc/augmented_cb_corr.h"
void WebRtcIlbcfix_AugmentedCbCorr(
int16_t *target, /* (i) Target vector */
int16_t *buffer, /* (i) Memory buffer */
int16_t *interpSamples, /* (i) buffer with
interpolated samples */
int32_t *crossDot, /* (o) The cross correlation between
the target and the Augmented
vector */
size_t low, /* (i) Lag to start from (typically
20) */
size_t high, /* (i) Lag to end at (typically 39) */
int scale) /* (i) Scale factor to use for
the crossDot */
{
size_t lagcount;
size_t ilow;
int16_t *targetPtr;
int32_t *crossDotPtr;
int16_t *iSPtr=interpSamples;
/* Calculate the correlation between the target and the
interpolated codebook. The correlation is calculated in
3 sections with the interpolated part in the middle */
crossDotPtr=crossDot;
for (lagcount=low; lagcount<=high; lagcount++) {
ilow = lagcount - 4;
/* Compute dot product for the first (lagcount-4) samples */
(*crossDotPtr) = WebRtcSpl_DotProductWithScale(target, buffer-lagcount, ilow, scale);
/* Compute dot product on the interpolated samples */
(*crossDotPtr) += WebRtcSpl_DotProductWithScale(target+ilow, iSPtr, 4, scale);
targetPtr = target + lagcount;
iSPtr += lagcount-ilow;
/* Compute dot product for the remaining samples */
(*crossDotPtr) += WebRtcSpl_DotProductWithScale(targetPtr, buffer-lagcount, SUBL-lagcount, scale);
crossDotPtr++;
}
}