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_DecoderInterpolateLsp.c
16
17 ******************************************************************/
18
19 #include "lsf_interpolate_to_poly_dec.h"
20 #include "bw_expand.h"
21 #include "defines.h"
22 #include "constants.h"
23
24 /*----------------------------------------------------------------*
25 * obtain synthesis and weighting filters form lsf coefficients
26 *---------------------------------------------------------------*/
27
WebRtcIlbcfix_DecoderInterpolateLsp(WebRtc_Word16 * syntdenum,WebRtc_Word16 * weightdenum,WebRtc_Word16 * lsfdeq,WebRtc_Word16 length,iLBC_Dec_Inst_t * iLBCdec_inst)28 void WebRtcIlbcfix_DecoderInterpolateLsp(
29 WebRtc_Word16 *syntdenum, /* (o) synthesis filter coefficients */
30 WebRtc_Word16 *weightdenum, /* (o) weighting denumerator
31 coefficients */
32 WebRtc_Word16 *lsfdeq, /* (i) dequantized lsf coefficients */
33 WebRtc_Word16 length, /* (i) length of lsf coefficient vector */
34 iLBC_Dec_Inst_t *iLBCdec_inst
35 /* (i) the decoder state structure */
36 ){
37 int i, pos, lp_length;
38 WebRtc_Word16 lp[LPC_FILTERORDER + 1], *lsfdeq2;
39
40 lsfdeq2 = lsfdeq + length;
41 lp_length = length + 1;
42
43 if (iLBCdec_inst->mode==30) {
44 /* subframe 1: Interpolation between old and first LSF */
45
46 WebRtcIlbcfix_LspInterpolate2PolyDec(lp, (*iLBCdec_inst).lsfdeqold, lsfdeq,
47 WebRtcIlbcfix_kLsfWeight30ms[0], length);
48 WEBRTC_SPL_MEMCPY_W16(syntdenum,lp,lp_length);
49 WebRtcIlbcfix_BwExpand(weightdenum, lp, (WebRtc_Word16*)WebRtcIlbcfix_kLpcChirpSyntDenum, (WebRtc_Word16)lp_length);
50
51 /* subframes 2 to 6: interpolation between first and last LSF */
52
53 pos = lp_length;
54 for (i = 1; i < 6; i++) {
55 WebRtcIlbcfix_LspInterpolate2PolyDec(lp, lsfdeq, lsfdeq2,
56 WebRtcIlbcfix_kLsfWeight30ms[i], length);
57 WEBRTC_SPL_MEMCPY_W16(syntdenum + pos,lp,lp_length);
58 WebRtcIlbcfix_BwExpand(weightdenum + pos, lp,
59 (WebRtc_Word16*)WebRtcIlbcfix_kLpcChirpSyntDenum, (WebRtc_Word16)lp_length);
60 pos += lp_length;
61 }
62 } else { /* iLBCdec_inst->mode=20 */
63 /* subframes 1 to 4: interpolation between old and new LSF */
64 pos = 0;
65 for (i = 0; i < iLBCdec_inst->nsub; i++) {
66 WebRtcIlbcfix_LspInterpolate2PolyDec(lp, iLBCdec_inst->lsfdeqold, lsfdeq,
67 WebRtcIlbcfix_kLsfWeight20ms[i], length);
68 WEBRTC_SPL_MEMCPY_W16(syntdenum+pos,lp,lp_length);
69 WebRtcIlbcfix_BwExpand(weightdenum+pos, lp,
70 (WebRtc_Word16*)WebRtcIlbcfix_kLpcChirpSyntDenum, (WebRtc_Word16)lp_length);
71 pos += lp_length;
72 }
73 }
74
75 /* update memory */
76
77 if (iLBCdec_inst->mode==30) {
78 WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->lsfdeqold, lsfdeq2, length);
79 } else {
80 WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->lsfdeqold, lsfdeq, length);
81 }
82 }
83