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_CreateAugmentedVec.c
16
17******************************************************************/
18
19#include "defines.h"
20#include "constants.h"
21
22/*----------------------------------------------------------------*
23 *  Recreate a specific codebook vector from the augmented part.
24 *
25 *----------------------------------------------------------------*/
26
27void WebRtcIlbcfix_CreateAugmentedVec(
28    size_t index,  /* (i) Index for the augmented vector to be created */
29    int16_t *buffer,  /* (i) Pointer to the end of the codebook memory that
30                                           is used for creation of the augmented codebook */
31    int16_t *cbVec  /* (o) The construced codebook vector */
32                                      ) {
33  size_t ilow;
34  int16_t *ppo, *ppi;
35  int16_t cbVecTmp[4];
36
37  ilow = index-4;
38
39  /* copy the first noninterpolated part */
40  ppo = buffer-index;
41  WEBRTC_SPL_MEMCPY_W16(cbVec, ppo, index);
42
43  /* interpolation */
44  ppo = buffer - 4;
45  ppi = buffer - index - 4;
46
47  /* perform cbVec[ilow+k] = ((ppi[k]*alphaTbl[k])>>15) + ((ppo[k]*alphaTbl[3-k])>>15);
48     for k = 0..3
49  */
50  WebRtcSpl_ElementwiseVectorMult(&cbVec[ilow], ppi, WebRtcIlbcfix_kAlpha, 4, 15);
51  WebRtcSpl_ReverseOrderMultArrayElements(cbVecTmp, ppo, &WebRtcIlbcfix_kAlpha[3], 4, 15);
52  WebRtcSpl_AddVectorsAndShift(&cbVec[ilow], &cbVec[ilow], cbVecTmp, 4, 0);
53
54  /* copy the second noninterpolated part */
55  ppo = buffer - index;
56  WEBRTC_SPL_MEMCPY_W16(cbVec+index,ppo,(SUBL-index));
57}
58