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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_AbsQuant.c
     16 
     17 ******************************************************************/
     18 
     19 #include "defines.h"
     20 #include "constants.h"
     21 #include "abs_quant_loop.h"
     22 
     23 
     24 /*----------------------------------------------------------------*
     25  *  predictive noise shaping encoding of scaled start state
     26  *  (subrutine for WebRtcIlbcfix_StateSearch)
     27  *---------------------------------------------------------------*/
     28 
     29 void WebRtcIlbcfix_AbsQuant(
     30     IlbcEncoder *iLBCenc_inst,
     31     /* (i) Encoder instance */
     32     iLBC_bits *iLBC_encbits, /* (i/o) Encoded bits (outputs idxForMax
     33                                    and idxVec, uses state_first as
     34                                    input) */
     35     int16_t *in,     /* (i) vector to encode */
     36     int16_t *weightDenum   /* (i) denominator of synthesis filter */
     37                             ) {
     38   int16_t *syntOut;
     39   size_t quantLen[2];
     40 
     41   /* Stack based */
     42   int16_t syntOutBuf[LPC_FILTERORDER+STATE_SHORT_LEN_30MS];
     43   int16_t in_weightedVec[STATE_SHORT_LEN_30MS+LPC_FILTERORDER];
     44   int16_t *in_weighted = &in_weightedVec[LPC_FILTERORDER];
     45 
     46   /* Initialize the buffers */
     47   WebRtcSpl_MemSetW16(syntOutBuf, 0, LPC_FILTERORDER+STATE_SHORT_LEN_30MS);
     48   syntOut = &syntOutBuf[LPC_FILTERORDER];
     49   /* Start with zero state */
     50   WebRtcSpl_MemSetW16(in_weightedVec, 0, LPC_FILTERORDER);
     51 
     52   /* Perform the quantization loop in two sections of length quantLen[i],
     53      where the perceptual weighting filter is updated at the subframe
     54      border */
     55 
     56   if (iLBC_encbits->state_first) {
     57     quantLen[0]=SUBL;
     58     quantLen[1]=iLBCenc_inst->state_short_len-SUBL;
     59   } else {
     60     quantLen[0]=iLBCenc_inst->state_short_len-SUBL;
     61     quantLen[1]=SUBL;
     62   }
     63 
     64   /* Calculate the weighted residual, switch perceptual weighting
     65      filter at the subframe border */
     66   WebRtcSpl_FilterARFastQ12(
     67       in, in_weighted,
     68       weightDenum, LPC_FILTERORDER+1, quantLen[0]);
     69   WebRtcSpl_FilterARFastQ12(
     70       &in[quantLen[0]], &in_weighted[quantLen[0]],
     71       &weightDenum[LPC_FILTERORDER+1], LPC_FILTERORDER+1, quantLen[1]);
     72 
     73   WebRtcIlbcfix_AbsQuantLoop(
     74       syntOut,
     75       in_weighted,
     76       weightDenum,
     77       quantLen,
     78       iLBC_encbits->idxVec);
     79 
     80 }
     81