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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_Refiner.c
     16 
     17 ******************************************************************/
     18 
     19 #include "defines.h"
     20 #include "constants.h"
     21 #include "enh_upsample.h"
     22 #include "my_corr.h"
     23 
     24 /*----------------------------------------------------------------*
     25  * find segment starting near idata+estSegPos that has highest
     26  * correlation with idata+centerStartPos through
     27  * idata+centerStartPos+ENH_BLOCKL-1 segment is found at a
     28  * resolution of ENH_UPSO times the original of the original
     29  * sampling rate
     30  *---------------------------------------------------------------*/
     31 
     32 void WebRtcIlbcfix_Refiner(
     33     size_t *updStartPos, /* (o) updated start point (Q-2) */
     34     int16_t *idata,   /* (i) original data buffer */
     35     size_t idatal,   /* (i) dimension of idata */
     36     size_t centerStartPos, /* (i) beginning center segment */
     37     size_t estSegPos,  /* (i) estimated beginning other segment (Q-2) */
     38     int16_t *surround,  /* (i/o) The contribution from this sequence
     39                                            summed with earlier contributions */
     40     int16_t gain    /* (i) Gain to use for this sequence */
     41                            ){
     42   size_t estSegPosRounded, searchSegStartPos, searchSegEndPos, corrdim;
     43   size_t tloc, tloc2, i;
     44 
     45   int32_t maxtemp, scalefact;
     46   int16_t *filtStatePtr, *polyPtr;
     47   /* Stack based */
     48   int16_t filt[7];
     49   int32_t corrVecUps[ENH_CORRDIM*ENH_UPS0];
     50   int32_t corrVecTemp[ENH_CORRDIM];
     51   int16_t vect[ENH_VECTL];
     52   int16_t corrVec[ENH_CORRDIM];
     53 
     54   /* defining array bounds */
     55 
     56   estSegPosRounded = (estSegPos - 2) >> 2;
     57 
     58   searchSegStartPos =
     59       (estSegPosRounded < ENH_SLOP) ? 0 : (estSegPosRounded - ENH_SLOP);
     60 
     61   searchSegEndPos = estSegPosRounded + ENH_SLOP;
     62   if ((searchSegEndPos + ENH_BLOCKL) >= idatal) {
     63     searchSegEndPos = idatal - ENH_BLOCKL - 1;
     64   }
     65 
     66   corrdim = searchSegEndPos + 1 - searchSegStartPos;
     67 
     68   /* compute upsampled correlation and find
     69      location of max */
     70 
     71   WebRtcIlbcfix_MyCorr(corrVecTemp, idata + searchSegStartPos,
     72                        corrdim + ENH_BLOCKL - 1, idata + centerStartPos,
     73                        ENH_BLOCKL);
     74 
     75   /* Calculate the rescaling factor for the correlation in order to
     76      put the correlation in a int16_t vector instead */
     77   maxtemp = WebRtcSpl_MaxAbsValueW32(corrVecTemp, corrdim);
     78 
     79   scalefact = WebRtcSpl_GetSizeInBits(maxtemp) - 15;
     80 
     81   if (scalefact > 0) {
     82     for (i = 0; i < corrdim; i++) {
     83       corrVec[i] = (int16_t)(corrVecTemp[i] >> scalefact);
     84     }
     85   } else {
     86     for (i = 0; i < corrdim; i++) {
     87       corrVec[i] = (int16_t)corrVecTemp[i];
     88     }
     89   }
     90   /* In order to guarantee that all values are initialized */
     91   for (i = corrdim; i < ENH_CORRDIM; i++) {
     92     corrVec[i] = 0;
     93   }
     94 
     95   /* Upsample the correlation */
     96   WebRtcIlbcfix_EnhUpsample(corrVecUps, corrVec);
     97 
     98   /* Find maximum */
     99   tloc = WebRtcSpl_MaxIndexW32(corrVecUps, ENH_UPS0 * corrdim);
    100 
    101   /* make vector can be upsampled without ever running outside
    102      bounds */
    103   *updStartPos = searchSegStartPos * 4 + tloc + 4;
    104 
    105   tloc2 = (tloc + 3) >> 2;
    106 
    107   /* initialize the vector to be filtered, stuff with zeros
    108      when data is outside idata buffer */
    109   if (ENH_FL0 > (searchSegStartPos + tloc2)) {
    110     const size_t st = ENH_FL0 - searchSegStartPos - tloc2;
    111     WebRtcSpl_MemSetW16(vect, 0, st);
    112     WEBRTC_SPL_MEMCPY_W16(&vect[st], idata, ENH_VECTL - st);
    113   } else {
    114     const size_t st = searchSegStartPos + tloc2 - ENH_FL0;
    115     if ((st + ENH_VECTL) > idatal) {
    116       const size_t en = st + ENH_VECTL - idatal;
    117       WEBRTC_SPL_MEMCPY_W16(vect, &idata[st], ENH_VECTL - en);
    118       WebRtcSpl_MemSetW16(&vect[ENH_VECTL - en], 0, en);
    119     } else {
    120       WEBRTC_SPL_MEMCPY_W16(vect, &idata[st], ENH_VECTL);
    121     }
    122   }
    123 
    124   /* compute the segment (this is actually a convolution) */
    125   filtStatePtr = filt + 6;
    126   polyPtr = (int16_t*)WebRtcIlbcfix_kEnhPolyPhaser[tloc2 * ENH_UPS0 - tloc];
    127   for (i = 0; i < 7; i++) {
    128     *filtStatePtr-- = *polyPtr++;
    129   }
    130 
    131   WebRtcSpl_FilterMAFastQ12(&vect[6], vect, filt, ENH_FLO_MULT2_PLUS1,
    132                             ENH_BLOCKL);
    133 
    134   /* Add the contribution from this vector (scaled with gain) to the total
    135      surround vector */
    136   WebRtcSpl_AddAffineVectorToVector(surround, vect, gain, 32768, 16,
    137                                     ENH_BLOCKL);
    138 
    139   return;
    140 }
    141