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
WebRtcIlbcfix_Vq3(int16_t * Xq,int16_t * index,int16_t * CB,int16_t * X,int16_t n_cb)26 void 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 = tmp * tmp;
45 for (i = 1; i < 3; i++) {
46 tmp = X[i] - CB[pos + i];
47 dist += 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