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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_InterpolateSamples.c
******************************************************************/
#include "modules/audio_coding/codecs/ilbc/interpolate_samples.h"
#include "modules/audio_coding/codecs/ilbc/constants.h"
#include "modules/audio_coding/codecs/ilbc/defines.h"
void WebRtcIlbcfix_InterpolateSamples(
int16_t *interpSamples, /* (o) The interpolated samples */
int16_t *CBmem, /* (i) The CB memory */
size_t lMem /* (i) Length of the CB memory */
) {
int16_t *ppi, *ppo, i, j, temp1, temp2;
int16_t *tmpPtr;
/* Calculate the 20 vectors of interpolated samples (4 samples each)
that are used in the codebooks for lag 20 to 39 */
tmpPtr = interpSamples;
for (j=0; j<20; j++) {
temp1 = 0;
temp2 = 3;
ppo = CBmem+lMem-4;
ppi = CBmem+lMem-j-24;
for (i=0; i<4; i++) {
*tmpPtr++ = (int16_t)((WebRtcIlbcfix_kAlpha[temp2] * *ppo) >> 15) +
(int16_t)((WebRtcIlbcfix_kAlpha[temp1] * *ppi) >> 15);
ppo++;
ppi++;
temp1++;
temp2--;
}
}
return;
}