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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_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 
     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     iLBC_Enc_Inst_t *iLBCenc_inst
     43     /* (i/o) the encoder state structure */
     44                                         ) {
     45   int i, pos, lp_length;
     46 
     47   int16_t *lsf2, *lsfdeq2;
     48   /* Stack based */
     49   int16_t lp[LPC_FILTERORDER + 1];
     50 
     51   lsf2 = lsf + length;
     52   lsfdeq2 = lsfdeq + length;
     53   lp_length = length + 1;
     54 
     55   if (iLBCenc_inst->mode==30) {
     56     /* subframe 1: Interpolation between old and first set of
     57        lsf coefficients */
     58 
     59     /* Calculate Analysis/Syntehsis filter from quantized LSF */
     60     WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfdeqold, lsfdeq,
     61                                          WebRtcIlbcfix_kLsfWeight30ms[0],
     62                                          length);
     63     WEBRTC_SPL_MEMCPY_W16(syntdenum, lp, lp_length);
     64 
     65     /* Calculate Weighting filter from quantized LSF */
     66     WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfold, lsf,
     67                                          WebRtcIlbcfix_kLsfWeight30ms[0],
     68                                          length);
     69     WebRtcIlbcfix_BwExpand(weightdenum, lp,
     70                            (int16_t*)WebRtcIlbcfix_kLpcChirpWeightDenum,
     71                            (int16_t)lp_length);
     72 
     73     /* subframe 2 to 6: Interpolation between first and second
     74        set of lsf coefficients */
     75 
     76     pos = lp_length;
     77     for (i = 1; i < iLBCenc_inst->nsub; i++) {
     78 
     79       /* Calculate Analysis/Syntehsis filter from quantized LSF */
     80       WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfdeq, lsfdeq2,
     81                                            WebRtcIlbcfix_kLsfWeight30ms[i],
     82                                            length);
     83       WEBRTC_SPL_MEMCPY_W16(syntdenum + pos, lp, lp_length);
     84 
     85       /* Calculate Weighting filter from quantized LSF */
     86       WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsf, lsf2,
     87                                            WebRtcIlbcfix_kLsfWeight30ms[i],
     88                                            length);
     89       WebRtcIlbcfix_BwExpand(weightdenum + pos, lp,
     90                              (int16_t*)WebRtcIlbcfix_kLpcChirpWeightDenum,
     91                              (int16_t)lp_length);
     92 
     93       pos += lp_length;
     94     }
     95 
     96     /* update memory */
     97 
     98     WEBRTC_SPL_MEMCPY_W16(lsfold, lsf2, length);
     99     WEBRTC_SPL_MEMCPY_W16(lsfdeqold, lsfdeq2, length);
    100 
    101   } else { /* iLBCenc_inst->mode==20 */
    102     pos = 0;
    103     for (i = 0; i < iLBCenc_inst->nsub; i++) {
    104 
    105       /* Calculate Analysis/Syntehsis filter from quantized LSF */
    106       WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfdeqold, lsfdeq,
    107                                            WebRtcIlbcfix_kLsfWeight20ms[i],
    108                                            length);
    109       WEBRTC_SPL_MEMCPY_W16(syntdenum + pos, lp, lp_length);
    110 
    111       /* Calculate Weighting filter from quantized LSF */
    112       WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfold, lsf,
    113                                            WebRtcIlbcfix_kLsfWeight20ms[i],
    114                                            length);
    115       WebRtcIlbcfix_BwExpand(weightdenum+pos, lp,
    116                              (int16_t*)WebRtcIlbcfix_kLpcChirpWeightDenum,
    117                              (int16_t)lp_length);
    118 
    119       pos += lp_length;
    120     }
    121 
    122     /* update memory */
    123 
    124     WEBRTC_SPL_MEMCPY_W16(lsfold, lsf, length);
    125     WEBRTC_SPL_MEMCPY_W16(lsfdeqold, lsfdeq, length);
    126 
    127   }
    128 
    129   return;
    130 }
    131