1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
|
/*
* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
/******************************************************************
iLBC Speech Coder ANSI-C Source Code
WebRtcIlbcfix_CreateAugmentedVec.c
******************************************************************/
#include "modules/audio_coding/codecs/ilbc/create_augmented_vec.h"
#include "common_audio/signal_processing/include/signal_processing_library.h"
#include "modules/audio_coding/codecs/ilbc/constants.h"
#include "modules/audio_coding/codecs/ilbc/defines.h"
#include "rtc_base/sanitizer.h"
/*----------------------------------------------------------------*
* Recreate a specific codebook vector from the augmented part.
*
*----------------------------------------------------------------*/
void WebRtcIlbcfix_CreateAugmentedVec(
size_t index, /* (i) Index for the augmented vector to be
created */
const int16_t* buffer, /* (i) Pointer to the end of the codebook memory
that is used for creation of the augmented
codebook */
int16_t* cbVec) { /* (o) The constructed codebook vector */
size_t ilow;
const int16_t *ppo, *ppi;
int16_t cbVecTmp[4];
/* Interpolation starts 4 elements before cbVec+index, but must not start
outside `cbVec`; clamping interp_len to stay within `cbVec`.
*/
size_t interp_len = WEBRTC_SPL_MIN(index, 4);
rtc_MsanCheckInitialized(buffer - index - interp_len, sizeof(buffer[0]),
index + interp_len);
ilow = index - interp_len;
/* copy the first noninterpolated part */
ppo = buffer-index;
WEBRTC_SPL_MEMCPY_W16(cbVec, ppo, index);
/* interpolation */
ppo = buffer - interp_len;
ppi = buffer - index - interp_len;
/* perform cbVec[ilow+k] = ((ppi[k]*alphaTbl[k])>>15) +
((ppo[k]*alphaTbl[interp_len-1-k])>>15);
for k = 0..interp_len-1
*/
WebRtcSpl_ElementwiseVectorMult(&cbVec[ilow], ppi, WebRtcIlbcfix_kAlpha,
interp_len, 15);
WebRtcSpl_ReverseOrderMultArrayElements(
cbVecTmp, ppo, &WebRtcIlbcfix_kAlpha[interp_len - 1], interp_len, 15);
WebRtcSpl_AddVectorsAndShift(&cbVec[ilow], &cbVec[ilow], cbVecTmp, interp_len,
0);
/* copy the second noninterpolated part */
ppo = buffer - index;
/* `tempbuff2` is declared in WebRtcIlbcfix_GetCbVec and is SUBL+5 elements
long. `buffer` points one element past the end of that vector, i.e., at
tempbuff2+SUBL+5. Since ppo=buffer-index, we cannot read any more than
`index` elements from `ppo`.
`cbVec` is declared to be SUBL elements long in WebRtcIlbcfix_CbConstruct.
Therefore, we can only write SUBL-index elements to cbVec+index.
These two conditions limit the number of elements to copy.
*/
WEBRTC_SPL_MEMCPY_W16(cbVec+index, ppo, WEBRTC_SPL_MIN(SUBL-index, index));
}
|
