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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     iLBC_Dec_Inst_t *iLBCdec_inst
     35     /* (i) the decoder state structure */
     36                                           ){
     37   int  i, pos, lp_length;
     38   int16_t  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, (int16_t*)WebRtcIlbcfix_kLpcChirpSyntDenum, (int16_t)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                              (int16_t*)WebRtcIlbcfix_kLpcChirpSyntDenum, (int16_t)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                              (int16_t*)WebRtcIlbcfix_kLpcChirpSyntDenum, (int16_t)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