Home | History | Annotate | Download | only in ilbc 
      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     IlbcEncoder *iLBCenc_inst
     43     /* (i/o) the encoder state structure */
     44                                         ) {
     45   size_t i;
     46   int pos, lp_length;
     47 
     48   int16_t *lsf2, *lsfdeq2;
     49   /* Stack based */
     50   int16_t lp[LPC_FILTERORDER + 1];
     51 
     52   lsf2 = lsf + length;
     53   lsfdeq2 = lsfdeq + length;
     54   lp_length = length + 1;
     55 
     56   if (iLBCenc_inst->mode==30) {
     57     /* subframe 1: Interpolation between old and first set of
     58        lsf coefficients */
     59 
     60     /* Calculate Analysis/Syntehsis filter from quantized LSF */
     61     WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfdeqold, lsfdeq,
     62                                          WebRtcIlbcfix_kLsfWeight30ms[0],
     63                                          length);
     64     WEBRTC_SPL_MEMCPY_W16(syntdenum, lp, lp_length);
     65 
     66     /* Calculate Weighting filter from quantized LSF */
     67     WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfold, lsf,
     68                                          WebRtcIlbcfix_kLsfWeight30ms[0],
     69                                          length);
     70     WebRtcIlbcfix_BwExpand(weightdenum, lp,
     71                            (int16_t*)WebRtcIlbcfix_kLpcChirpWeightDenum,
     72                            (int16_t)lp_length);
     73 
     74     /* subframe 2 to 6: Interpolation between first and second
     75        set of lsf coefficients */
     76 
     77     pos = lp_length;
     78     for (i = 1; i < iLBCenc_inst->nsub; i++) {
     79 
     80       /* Calculate Analysis/Syntehsis filter from quantized LSF */
     81       WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfdeq, lsfdeq2,
     82                                            WebRtcIlbcfix_kLsfWeight30ms[i],
     83                                            length);
     84       WEBRTC_SPL_MEMCPY_W16(syntdenum + pos, lp, lp_length);
     85 
     86       /* Calculate Weighting filter from quantized LSF */
     87       WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsf, lsf2,
     88                                            WebRtcIlbcfix_kLsfWeight30ms[i],
     89                                            length);
     90       WebRtcIlbcfix_BwExpand(weightdenum + pos, lp,
     91                              (int16_t*)WebRtcIlbcfix_kLpcChirpWeightDenum,
     92                              (int16_t)lp_length);
     93 
     94       pos += lp_length;
     95     }
     96 
     97     /* update memory */
     98 
     99     WEBRTC_SPL_MEMCPY_W16(lsfold, lsf2, length);
    100     WEBRTC_SPL_MEMCPY_W16(lsfdeqold, lsfdeq2, length);
    101 
    102   } else { /* iLBCenc_inst->mode==20 */
    103     pos = 0;
    104     for (i = 0; i < iLBCenc_inst->nsub; i++) {
    105 
    106       /* Calculate Analysis/Syntehsis filter from quantized LSF */
    107       WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfdeqold, lsfdeq,
    108                                            WebRtcIlbcfix_kLsfWeight20ms[i],
    109                                            length);
    110       WEBRTC_SPL_MEMCPY_W16(syntdenum + pos, lp, lp_length);
    111 
    112       /* Calculate Weighting filter from quantized LSF */
    113       WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfold, lsf,
    114                                            WebRtcIlbcfix_kLsfWeight20ms[i],
    115                                            length);
    116       WebRtcIlbcfix_BwExpand(weightdenum+pos, lp,
    117                              (int16_t*)WebRtcIlbcfix_kLpcChirpWeightDenum,
    118                              (int16_t)lp_length);
    119 
    120       pos += lp_length;
    121     }
    122 
    123     /* update memory */
    124 
    125     WEBRTC_SPL_MEMCPY_W16(lsfold, lsf, length);
    126     WEBRTC_SPL_MEMCPY_W16(lsfdeqold, lsfdeq, length);
    127 
    128   }
    129 
    130   return;
    131 }
    132