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
WebRtcIlbcfix_CreateAugmentedVec(size_t index,int16_t * buffer,int16_t * cbVec)27 void 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