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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_GetCbVec.c
     16 
     17 ******************************************************************/
     18 
     19 #include "defines.h"
     20 #include "constants.h"
     21 #include "create_augmented_vec.h"
     22 
     23 /*----------------------------------------------------------------*
     24  *  Construct codebook vector for given index.
     25  *---------------------------------------------------------------*/
     26 
     27 void WebRtcIlbcfix_GetCbVec(
     28     int16_t *cbvec,   /* (o) Constructed codebook vector */
     29     int16_t *mem,   /* (i) Codebook buffer */
     30     size_t index,   /* (i) Codebook index */
     31     size_t lMem,   /* (i) Length of codebook buffer */
     32     size_t cbveclen   /* (i) Codebook vector length */
     33                             ){
     34   size_t k, base_size;
     35   size_t lag;
     36   /* Stack based */
     37   int16_t tempbuff2[SUBL+5];
     38 
     39   /* Determine size of codebook sections */
     40 
     41   base_size=lMem-cbveclen+1;
     42 
     43   if (cbveclen==SUBL) {
     44     base_size += cbveclen / 2;
     45   }
     46 
     47   /* No filter -> First codebook section */
     48 
     49   if (index<lMem-cbveclen+1) {
     50 
     51     /* first non-interpolated vectors */
     52 
     53     k=index+cbveclen;
     54     /* get vector */
     55     WEBRTC_SPL_MEMCPY_W16(cbvec, mem+lMem-k, cbveclen);
     56 
     57   } else if (index < base_size) {
     58 
     59     /* Calculate lag */
     60 
     61     k = (2 * (index - (lMem - cbveclen + 1))) + cbveclen;
     62 
     63     lag = k / 2;
     64 
     65     WebRtcIlbcfix_CreateAugmentedVec(lag, mem+lMem, cbvec);
     66 
     67   }
     68 
     69   /* Higher codebbok section based on filtering */
     70 
     71   else {
     72 
     73     size_t memIndTest;
     74 
     75     /* first non-interpolated vectors */
     76 
     77     if (index-base_size<lMem-cbveclen+1) {
     78 
     79       /* Set up filter memory, stuff zeros outside memory buffer */
     80 
     81       memIndTest = lMem-(index-base_size+cbveclen);
     82 
     83       WebRtcSpl_MemSetW16(mem-CB_HALFFILTERLEN, 0, CB_HALFFILTERLEN);
     84       WebRtcSpl_MemSetW16(mem+lMem, 0, CB_HALFFILTERLEN);
     85 
     86       /* do filtering to get the codebook vector */
     87 
     88       WebRtcSpl_FilterMAFastQ12(
     89           &mem[memIndTest+4], cbvec, (int16_t*)WebRtcIlbcfix_kCbFiltersRev,
     90           CB_FILTERLEN, cbveclen);
     91     }
     92 
     93     /* interpolated vectors */
     94 
     95     else {
     96       /* Stuff zeros outside memory buffer  */
     97       memIndTest = lMem-cbveclen-CB_FILTERLEN;
     98       WebRtcSpl_MemSetW16(mem+lMem, 0, CB_HALFFILTERLEN);
     99 
    100       /* do filtering */
    101       WebRtcSpl_FilterMAFastQ12(
    102           &mem[memIndTest+7], tempbuff2, (int16_t*)WebRtcIlbcfix_kCbFiltersRev,
    103           CB_FILTERLEN, cbveclen+5);
    104 
    105       /* Calculate lag index */
    106       lag = (cbveclen<<1)-20+index-base_size-lMem-1;
    107 
    108       WebRtcIlbcfix_CreateAugmentedVec(lag, tempbuff2+SUBL+5, cbvec);
    109     }
    110   }
    111 }
    112