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