1/*
2 *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11/******************************************************************
12
13 iLBC Speech Coder ANSI-C Source Code
14
15 WebRtcIlbcfix_BwExpand.c
16
17******************************************************************/
18
19#include "defines.h"
20
21/*----------------------------------------------------------------*
22 *  lpc bandwidth expansion
23 *---------------------------------------------------------------*/
24
25/* The output is in the same domain as the input */
26void WebRtcIlbcfix_BwExpand(
27    int16_t *out, /* (o) the bandwidth expanded lpc coefficients */
28    int16_t *in,  /* (i) the lpc coefficients before bandwidth
29                                   expansion */
30    int16_t *coef, /* (i) the bandwidth expansion factor Q15 */
31    int16_t length /* (i) the length of lpc coefficient vectors */
32                            ) {
33  int i;
34
35  out[0] = in[0];
36  for (i = 1; i < length; i++) {
37    /* out[i] = coef[i] * in[i] with rounding.
38       in[] and out[] are in Q12 and coef[] is in Q15
39    */
40    out[i] = (int16_t)((WEBRTC_SPL_MUL_16_16(coef[i], in[i])+16384)>>15);
41  }
42}
43