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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_BwExpand.c
******************************************************************/
#include "modules/audio_coding/codecs/ilbc/bw_expand.h"
#include "modules/audio_coding/codecs/ilbc/defines.h"
/*----------------------------------------------------------------*
* lpc bandwidth expansion
*---------------------------------------------------------------*/
/* The output is in the same domain as the input */
void WebRtcIlbcfix_BwExpand(
int16_t *out, /* (o) the bandwidth expanded lpc coefficients */
int16_t *in, /* (i) the lpc coefficients before bandwidth
expansion */
int16_t *coef, /* (i) the bandwidth expansion factor Q15 */
int16_t length /* (i) the length of lpc coefficient vectors */
) {
int i;
out[0] = in[0];
for (i = 1; i < length; i++) {
/* out[i] = coef[i] * in[i] with rounding.
in[] and out[] are in Q12 and coef[] is in Q15
*/
out[i] = (int16_t)((coef[i] * in[i] + 16384) >> 15);
}
}