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_GetCbVec.c
16
17 ******************************************************************/
18
19 #include "get_cd_vec.h"
20
21 #include "defines.h"
22 #include "constants.h"
23 #include "create_augmented_vec.h"
24
25 /*----------------------------------------------------------------*
26 * Construct codebook vector for given index.
27 *---------------------------------------------------------------*/
28
WebRtcIlbcfix_GetCbVec(int16_t * cbvec,int16_t * mem,size_t index,size_t lMem,size_t cbveclen)29 bool WebRtcIlbcfix_GetCbVec(
30 int16_t *cbvec, /* (o) Constructed codebook vector */
31 int16_t *mem, /* (i) Codebook buffer */
32 size_t index, /* (i) Codebook index */
33 size_t lMem, /* (i) Length of codebook buffer */
34 size_t cbveclen /* (i) Codebook vector length */
35 ){
36 size_t k, base_size;
37 size_t lag;
38 /* Stack based */
39 int16_t tempbuff2[SUBL+5];
40
41 /* Determine size of codebook sections */
42
43 base_size=lMem-cbveclen+1;
44
45 if (cbveclen==SUBL) {
46 base_size += cbveclen / 2;
47 }
48
49 /* No filter -> First codebook section */
50
51 if (index<lMem-cbveclen+1) {
52
53 /* first non-interpolated vectors */
54
55 k=index+cbveclen;
56 /* get vector */
57 WEBRTC_SPL_MEMCPY_W16(cbvec, mem+lMem-k, cbveclen);
58
59 } else if (index < base_size) {
60
61 /* Calculate lag */
62
63 k = (2 * (index - (lMem - cbveclen + 1))) + cbveclen;
64
65 lag = k / 2;
66
67 WebRtcIlbcfix_CreateAugmentedVec(lag, mem+lMem, cbvec);
68
69 }
70
71 /* Higher codebbok section based on filtering */
72
73 else {
74
75 size_t memIndTest;
76
77 /* first non-interpolated vectors */
78
79 if (index-base_size<lMem-cbveclen+1) {
80
81 /* Set up filter memory, stuff zeros outside memory buffer */
82
83 memIndTest = lMem-(index-base_size+cbveclen);
84
85 WebRtcSpl_MemSetW16(mem-CB_HALFFILTERLEN, 0, CB_HALFFILTERLEN);
86 WebRtcSpl_MemSetW16(mem+lMem, 0, CB_HALFFILTERLEN);
87
88 /* do filtering to get the codebook vector */
89
90 WebRtcSpl_FilterMAFastQ12(
91 &mem[memIndTest+4], cbvec, (int16_t*)WebRtcIlbcfix_kCbFiltersRev,
92 CB_FILTERLEN, cbveclen);
93 }
94
95 /* interpolated vectors */
96
97 else {
98 if (cbveclen < SUBL) {
99 // We're going to fill in cbveclen + 5 elements of tempbuff2 in
100 // WebRtcSpl_FilterMAFastQ12, less than the SUBL + 5 elements we'll be
101 // using in WebRtcIlbcfix_CreateAugmentedVec. This error is caused by
102 // bad values in |index| (which come from the encoded stream). Tell the
103 // caller that things went south, and that the decoder state is now
104 // corrupt (because it's half-way through an update that we can't
105 // complete).
106 return false;
107 }
108
109 /* Stuff zeros outside memory buffer */
110 memIndTest = lMem-cbveclen-CB_FILTERLEN;
111 WebRtcSpl_MemSetW16(mem+lMem, 0, CB_HALFFILTERLEN);
112
113 /* do filtering */
114 WebRtcSpl_FilterMAFastQ12(
115 &mem[memIndTest+7], tempbuff2, (int16_t*)WebRtcIlbcfix_kCbFiltersRev,
116 CB_FILTERLEN, cbveclen+5);
117
118 /* Calculate lag index */
119 lag = (cbveclen<<1)-20+index-base_size-lMem-1;
120
121 WebRtcIlbcfix_CreateAugmentedVec(lag, tempbuff2+SUBL+5, cbvec);
122 }
123 }
124
125 return true; // Success.
126 }
127