| /* |
| * 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_DecoderInterpolateLsp.c |
| |
| ******************************************************************/ |
| |
| #include "lsf_interpolate_to_poly_dec.h" |
| #include "bw_expand.h" |
| #include "defines.h" |
| #include "constants.h" |
| |
| /*----------------------------------------------------------------* |
| * obtain synthesis and weighting filters form lsf coefficients |
| *---------------------------------------------------------------*/ |
| |
| void WebRtcIlbcfix_DecoderInterpolateLsp( |
| WebRtc_Word16 *syntdenum, /* (o) synthesis filter coefficients */ |
| WebRtc_Word16 *weightdenum, /* (o) weighting denumerator |
| coefficients */ |
| WebRtc_Word16 *lsfdeq, /* (i) dequantized lsf coefficients */ |
| WebRtc_Word16 length, /* (i) length of lsf coefficient vector */ |
| iLBC_Dec_Inst_t *iLBCdec_inst |
| /* (i) the decoder state structure */ |
| ){ |
| int i, pos, lp_length; |
| WebRtc_Word16 lp[LPC_FILTERORDER + 1], *lsfdeq2; |
| |
| lsfdeq2 = lsfdeq + length; |
| lp_length = length + 1; |
| |
| if (iLBCdec_inst->mode==30) { |
| /* subframe 1: Interpolation between old and first LSF */ |
| |
| WebRtcIlbcfix_LspInterpolate2PolyDec(lp, (*iLBCdec_inst).lsfdeqold, lsfdeq, |
| WebRtcIlbcfix_kLsfWeight30ms[0], length); |
| WEBRTC_SPL_MEMCPY_W16(syntdenum,lp,lp_length); |
| WebRtcIlbcfix_BwExpand(weightdenum, lp, (WebRtc_Word16*)WebRtcIlbcfix_kLpcChirpSyntDenum, (WebRtc_Word16)lp_length); |
| |
| /* subframes 2 to 6: interpolation between first and last LSF */ |
| |
| pos = lp_length; |
| for (i = 1; i < 6; i++) { |
| WebRtcIlbcfix_LspInterpolate2PolyDec(lp, lsfdeq, lsfdeq2, |
| WebRtcIlbcfix_kLsfWeight30ms[i], length); |
| WEBRTC_SPL_MEMCPY_W16(syntdenum + pos,lp,lp_length); |
| WebRtcIlbcfix_BwExpand(weightdenum + pos, lp, |
| (WebRtc_Word16*)WebRtcIlbcfix_kLpcChirpSyntDenum, (WebRtc_Word16)lp_length); |
| pos += lp_length; |
| } |
| } else { /* iLBCdec_inst->mode=20 */ |
| /* subframes 1 to 4: interpolation between old and new LSF */ |
| pos = 0; |
| for (i = 0; i < iLBCdec_inst->nsub; i++) { |
| WebRtcIlbcfix_LspInterpolate2PolyDec(lp, iLBCdec_inst->lsfdeqold, lsfdeq, |
| WebRtcIlbcfix_kLsfWeight20ms[i], length); |
| WEBRTC_SPL_MEMCPY_W16(syntdenum+pos,lp,lp_length); |
| WebRtcIlbcfix_BwExpand(weightdenum+pos, lp, |
| (WebRtc_Word16*)WebRtcIlbcfix_kLpcChirpSyntDenum, (WebRtc_Word16)lp_length); |
| pos += lp_length; |
| } |
| } |
| |
| /* update memory */ |
| |
| if (iLBCdec_inst->mode==30) { |
| WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->lsfdeqold, lsfdeq2, length); |
| } else { |
| WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->lsfdeqold, lsfdeq, length); |
| } |
| } |