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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_AbsQuantLoop.c
     16 
     17 ******************************************************************/
     18 
     19 #include "defines.h"
     20 #include "constants.h"
     21 #include "sort_sq.h"
     22 
     23 void WebRtcIlbcfix_AbsQuantLoop(int16_t *syntOutIN, int16_t *in_weightedIN,
     24                                 int16_t *weightDenumIN, int16_t *quantLenIN,
     25                                 int16_t *idxVecIN ) {
     26   int n, k1, k2;
     27   int16_t index;
     28   int32_t toQW32;
     29   int32_t toQ32;
     30   int16_t tmp16a;
     31   int16_t xq;
     32 
     33   int16_t *syntOut   = syntOutIN;
     34   int16_t *in_weighted  = in_weightedIN;
     35   int16_t *weightDenum  = weightDenumIN;
     36   int16_t *quantLen  = quantLenIN;
     37   int16_t *idxVec   = idxVecIN;
     38 
     39   n=0;
     40 
     41   for(k1=0;k1<2;k1++) {
     42     for(k2=0;k2<quantLen[k1];k2++){
     43 
     44       /* Filter to get the predicted value */
     45       WebRtcSpl_FilterARFastQ12(
     46           syntOut, syntOut,
     47           weightDenum, LPC_FILTERORDER+1, 1);
     48 
     49       /* the quantizer */
     50       toQW32 = (int32_t)(*in_weighted) - (int32_t)(*syntOut);
     51 
     52       toQ32 = (((int32_t)toQW32)<<2);
     53 
     54       if (toQ32 > 32767) {
     55         toQ32 = (int32_t) 32767;
     56       } else if (toQ32 < -32768) {
     57         toQ32 = (int32_t) -32768;
     58       }
     59 
     60       /* Quantize the state */
     61       if (toQW32<(-7577)) {
     62         /* To prevent negative overflow */
     63         index=0;
     64       } else if (toQW32>8151) {
     65         /* To prevent positive overflow */
     66         index=7;
     67       } else {
     68         /* Find the best quantization index
     69            (state_sq3Tbl is in Q13 and toQ is in Q11)
     70         */
     71         WebRtcIlbcfix_SortSq(&xq, &index,
     72                              (int16_t)toQ32,
     73                              WebRtcIlbcfix_kStateSq3, 8);
     74       }
     75 
     76       /* Store selected index */
     77       (*idxVec++) = index;
     78 
     79       /* Compute decoded sample and update of the prediction filter */
     80       tmp16a = ((WebRtcIlbcfix_kStateSq3[index] + 2 ) >> 2);
     81 
     82       *syntOut     = (int16_t) (tmp16a + (int32_t)(*in_weighted) - toQW32);
     83 
     84       n++;
     85       syntOut++; in_weighted++;
     86     }
     87     /* Update perceptual weighting filter at subframe border */
     88     weightDenum += 11;
     89   }
     90 }
     91