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_Vq3.c
16
17******************************************************************/
18
19#include "vq3.h"
20#include "constants.h"
21
22/*----------------------------------------------------------------*
23 *  vector quantization
24 *---------------------------------------------------------------*/
25
26void WebRtcIlbcfix_Vq3(
27    int16_t *Xq, /* quantized vector (Q13) */
28    int16_t *index,
29    int16_t *CB, /* codebook in Q13 */
30    int16_t *X,  /* vector to quantize (Q13) */
31    int16_t n_cb
32                       ){
33  int16_t i, j;
34  int16_t pos, minindex=0;
35  int16_t tmp;
36  int32_t dist, mindist;
37
38  pos = 0;
39  mindist = WEBRTC_SPL_WORD32_MAX; /* start value */
40
41  /* Find the codebook with the lowest square distance */
42  for (j = 0; j < n_cb; j++) {
43    tmp = X[0] - CB[pos];
44    dist = WEBRTC_SPL_MUL_16_16(tmp, tmp);
45    for (i = 1; i < 3; i++) {
46      tmp = X[i] - CB[pos + i];
47      dist += WEBRTC_SPL_MUL_16_16(tmp, tmp);
48    }
49
50    if (dist < mindist) {
51      mindist = dist;
52      minindex = j;
53    }
54    pos += 3;
55  }
56
57  /* Store the quantized codebook and the index */
58  for (i = 0; i < 3; i++) {
59    Xq[i] = CB[minindex*3 + i];
60  }
61  *index = minindex;
62
63}
64