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_SimpleInterpolateLsf.c
16
17 ******************************************************************/
18
19 #include "defines.h"
20 #include "lsf_interpolate_to_poly_enc.h"
21 #include "bw_expand.h"
22 #include "constants.h"
23
24 /*----------------------------------------------------------------*
25 * lsf interpolator (subrutine to LPCencode)
26 *---------------------------------------------------------------*/
27
WebRtcIlbcfix_SimpleInterpolateLsf(int16_t * syntdenum,int16_t * weightdenum,int16_t * lsf,int16_t * lsfdeq,int16_t * lsfold,int16_t * lsfdeqold,int16_t length,IlbcEncoder * iLBCenc_inst)28 void WebRtcIlbcfix_SimpleInterpolateLsf(
29 int16_t *syntdenum, /* (o) the synthesis filter denominator
30 resulting from the quantized
31 interpolated lsf Q12 */
32 int16_t *weightdenum, /* (o) the weighting filter denominator
33 resulting from the unquantized
34 interpolated lsf Q12 */
35 int16_t *lsf, /* (i) the unquantized lsf coefficients Q13 */
36 int16_t *lsfdeq, /* (i) the dequantized lsf coefficients Q13 */
37 int16_t *lsfold, /* (i) the unquantized lsf coefficients of
38 the previous signal frame Q13 */
39 int16_t *lsfdeqold, /* (i) the dequantized lsf coefficients of the
40 previous signal frame Q13 */
41 int16_t length, /* (i) should equate FILTERORDER */
42 IlbcEncoder *iLBCenc_inst
43 /* (i/o) the encoder state structure */
44 ) {
45 size_t i;
46 int pos, lp_length;
47
48 int16_t *lsf2, *lsfdeq2;
49 /* Stack based */
50 int16_t lp[LPC_FILTERORDER + 1];
51
52 lsf2 = lsf + length;
53 lsfdeq2 = lsfdeq + length;
54 lp_length = length + 1;
55
56 if (iLBCenc_inst->mode==30) {
57 /* subframe 1: Interpolation between old and first set of
58 lsf coefficients */
59
60 /* Calculate Analysis/Syntehsis filter from quantized LSF */
61 WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfdeqold, lsfdeq,
62 WebRtcIlbcfix_kLsfWeight30ms[0],
63 length);
64 WEBRTC_SPL_MEMCPY_W16(syntdenum, lp, lp_length);
65
66 /* Calculate Weighting filter from quantized LSF */
67 WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfold, lsf,
68 WebRtcIlbcfix_kLsfWeight30ms[0],
69 length);
70 WebRtcIlbcfix_BwExpand(weightdenum, lp,
71 (int16_t*)WebRtcIlbcfix_kLpcChirpWeightDenum,
72 (int16_t)lp_length);
73
74 /* subframe 2 to 6: Interpolation between first and second
75 set of lsf coefficients */
76
77 pos = lp_length;
78 for (i = 1; i < iLBCenc_inst->nsub; i++) {
79
80 /* Calculate Analysis/Syntehsis filter from quantized LSF */
81 WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfdeq, lsfdeq2,
82 WebRtcIlbcfix_kLsfWeight30ms[i],
83 length);
84 WEBRTC_SPL_MEMCPY_W16(syntdenum + pos, lp, lp_length);
85
86 /* Calculate Weighting filter from quantized LSF */
87 WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsf, lsf2,
88 WebRtcIlbcfix_kLsfWeight30ms[i],
89 length);
90 WebRtcIlbcfix_BwExpand(weightdenum + pos, lp,
91 (int16_t*)WebRtcIlbcfix_kLpcChirpWeightDenum,
92 (int16_t)lp_length);
93
94 pos += lp_length;
95 }
96
97 /* update memory */
98
99 WEBRTC_SPL_MEMCPY_W16(lsfold, lsf2, length);
100 WEBRTC_SPL_MEMCPY_W16(lsfdeqold, lsfdeq2, length);
101
102 } else { /* iLBCenc_inst->mode==20 */
103 pos = 0;
104 for (i = 0; i < iLBCenc_inst->nsub; i++) {
105
106 /* Calculate Analysis/Syntehsis filter from quantized LSF */
107 WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfdeqold, lsfdeq,
108 WebRtcIlbcfix_kLsfWeight20ms[i],
109 length);
110 WEBRTC_SPL_MEMCPY_W16(syntdenum + pos, lp, lp_length);
111
112 /* Calculate Weighting filter from quantized LSF */
113 WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfold, lsf,
114 WebRtcIlbcfix_kLsfWeight20ms[i],
115 length);
116 WebRtcIlbcfix_BwExpand(weightdenum+pos, lp,
117 (int16_t*)WebRtcIlbcfix_kLpcChirpWeightDenum,
118 (int16_t)lp_length);
119
120 pos += lp_length;
121 }
122
123 /* update memory */
124
125 WEBRTC_SPL_MEMCPY_W16(lsfold, lsf, length);
126 WEBRTC_SPL_MEMCPY_W16(lsfdeqold, lsfdeq, length);
127
128 }
129
130 return;
131 }
132