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_CbConstruct.c
16
17 ******************************************************************/
18
19 #include "defines.h"
20 #include "gain_dequant.h"
21 #include "get_cd_vec.h"
22
23 /*----------------------------------------------------------------*
24 * Construct decoded vector from codebook and gains.
25 *---------------------------------------------------------------*/
26
WebRtcIlbcfix_CbConstruct(int16_t * decvector,int16_t * index,int16_t * gain_index,int16_t * mem,size_t lMem,size_t veclen)27 void WebRtcIlbcfix_CbConstruct(
28 int16_t *decvector, /* (o) Decoded vector */
29 int16_t *index, /* (i) Codebook indices */
30 int16_t *gain_index, /* (i) Gain quantization indices */
31 int16_t *mem, /* (i) Buffer for codevector construction */
32 size_t lMem, /* (i) Length of buffer */
33 size_t veclen /* (i) Length of vector */
34 ){
35 size_t j;
36 int16_t gain[CB_NSTAGES];
37 /* Stack based */
38 int16_t cbvec0[SUBL];
39 int16_t cbvec1[SUBL];
40 int16_t cbvec2[SUBL];
41 int32_t a32;
42 int16_t *gainPtr;
43
44 /* gain de-quantization */
45
46 gain[0] = WebRtcIlbcfix_GainDequant(gain_index[0], 16384, 0);
47 gain[1] = WebRtcIlbcfix_GainDequant(gain_index[1], gain[0], 1);
48 gain[2] = WebRtcIlbcfix_GainDequant(gain_index[2], gain[1], 2);
49
50 /* codebook vector construction and construction of total vector */
51
52 /* Stack based */
53 WebRtcIlbcfix_GetCbVec(cbvec0, mem, (size_t)index[0], lMem, veclen);
54 WebRtcIlbcfix_GetCbVec(cbvec1, mem, (size_t)index[1], lMem, veclen);
55 WebRtcIlbcfix_GetCbVec(cbvec2, mem, (size_t)index[2], lMem, veclen);
56
57 gainPtr = &gain[0];
58 for (j=0;j<veclen;j++) {
59 a32 = (*gainPtr++) * cbvec0[j];
60 a32 += (*gainPtr++) * cbvec1[j];
61 a32 += (*gainPtr) * cbvec2[j];
62 gainPtr -= 2;
63 decvector[j] = (int16_t)((a32 + 8192) >> 14);
64 }
65
66 return;
67 }
68