blob: ef5488322cb4de2cc59fbe982711711435103ad2 (
plain)
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
|
/*
* 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_SimpleLsfDeQ.c
******************************************************************/
#include "defines.h"
#include "constants.h"
/*----------------------------------------------------------------*
* obtain dequantized lsf coefficients from quantization index
*---------------------------------------------------------------*/
void WebRtcIlbcfix_SimpleLsfDeQ(
int16_t *lsfdeq, /* (o) dequantized lsf coefficients */
int16_t *index, /* (i) quantization index */
int16_t lpc_n /* (i) number of LPCs */
){
int i, j, pos, cb_pos;
/* decode first LSF */
pos = 0;
cb_pos = 0;
for (i = 0; i < LSF_NSPLIT; i++) {
for (j = 0; j < WebRtcIlbcfix_kLsfDimCb[i]; j++) {
lsfdeq[pos + j] = WebRtcIlbcfix_kLsfCb[cb_pos +
WEBRTC_SPL_MUL_16_16(index[i], WebRtcIlbcfix_kLsfDimCb[i]) + j];
}
pos += WebRtcIlbcfix_kLsfDimCb[i];
cb_pos += WEBRTC_SPL_MUL_16_16(WebRtcIlbcfix_kLsfSizeCb[i], WebRtcIlbcfix_kLsfDimCb[i]);
}
if (lpc_n>1) {
/* decode last LSF */
pos = 0;
cb_pos = 0;
for (i = 0; i < LSF_NSPLIT; i++) {
for (j = 0; j < WebRtcIlbcfix_kLsfDimCb[i]; j++) {
lsfdeq[LPC_FILTERORDER + pos + j] = WebRtcIlbcfix_kLsfCb[cb_pos +
WEBRTC_SPL_MUL_16_16(index[LSF_NSPLIT + i], WebRtcIlbcfix_kLsfDimCb[i]) + j];
}
pos += WebRtcIlbcfix_kLsfDimCb[i];
cb_pos += WEBRTC_SPL_MUL_16_16(WebRtcIlbcfix_kLsfSizeCb[i], WebRtcIlbcfix_kLsfDimCb[i]);
}
}
return;
}
|