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      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 
     28 void WebRtcIlbcfix_DecoderInterpolateLsp(
     29     int16_t *syntdenum,  /* (o) synthesis filter coefficients */
     30     int16_t *weightdenum, /* (o) weighting denumerator
     31                                    coefficients */
     32     int16_t *lsfdeq,   /* (i) dequantized lsf coefficients */
     33     int16_t length,   /* (i) length of lsf coefficient vector */
     34     IlbcDecoder *iLBCdec_inst
     35     /* (i) the decoder state structure */
     36                                           ){
     37   size_t i;
     38   int pos, lp_length;
     39   int16_t  lp[LPC_FILTERORDER + 1], *lsfdeq2;
     40 
     41   lsfdeq2 = lsfdeq + length;
     42   lp_length = length + 1;
     43 
     44   if (iLBCdec_inst->mode==30) {
     45     /* subframe 1: Interpolation between old and first LSF */
     46 
     47     WebRtcIlbcfix_LspInterpolate2PolyDec(lp, (*iLBCdec_inst).lsfdeqold, lsfdeq,
     48                                          WebRtcIlbcfix_kLsfWeight30ms[0], length);
     49     WEBRTC_SPL_MEMCPY_W16(syntdenum,lp,lp_length);
     50     WebRtcIlbcfix_BwExpand(weightdenum, lp, (int16_t*)WebRtcIlbcfix_kLpcChirpSyntDenum, (int16_t)lp_length);
     51 
     52     /* subframes 2 to 6: interpolation between first and last LSF */
     53 
     54     pos = lp_length;
     55     for (i = 1; i < 6; i++) {
     56       WebRtcIlbcfix_LspInterpolate2PolyDec(lp, lsfdeq, lsfdeq2,
     57                                            WebRtcIlbcfix_kLsfWeight30ms[i], length);
     58       WEBRTC_SPL_MEMCPY_W16(syntdenum + pos,lp,lp_length);
     59       WebRtcIlbcfix_BwExpand(weightdenum + pos, lp,
     60                              (int16_t*)WebRtcIlbcfix_kLpcChirpSyntDenum, (int16_t)lp_length);
     61       pos += lp_length;
     62     }
     63   } else { /* iLBCdec_inst->mode=20 */
     64     /* subframes 1 to 4: interpolation between old and new LSF */
     65     pos = 0;
     66     for (i = 0; i < iLBCdec_inst->nsub; i++) {
     67       WebRtcIlbcfix_LspInterpolate2PolyDec(lp, iLBCdec_inst->lsfdeqold, lsfdeq,
     68                                            WebRtcIlbcfix_kLsfWeight20ms[i], length);
     69       WEBRTC_SPL_MEMCPY_W16(syntdenum+pos,lp,lp_length);
     70       WebRtcIlbcfix_BwExpand(weightdenum+pos, lp,
     71                              (int16_t*)WebRtcIlbcfix_kLpcChirpSyntDenum, (int16_t)lp_length);
     72       pos += lp_length;
     73     }
     74   }
     75 
     76   /* update memory */
     77 
     78   if (iLBCdec_inst->mode==30) {
     79     WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->lsfdeqold, lsfdeq2, length);
     80   } else {
     81     WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->lsfdeqold, lsfdeq, length);
     82   }
     83 }
     84