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/*
* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
/******************************************************************
iLBC Speech Coder ANSI-C Source Code
WebRtcIlbcfix_Vq3.c
******************************************************************/
#include "vq3.h"
#include "constants.h"
/*----------------------------------------------------------------*
* vector quantization
*---------------------------------------------------------------*/
void WebRtcIlbcfix_Vq3(
int16_t *Xq, /* quantized vector (Q13) */
int16_t *index,
int16_t *CB, /* codebook in Q13 */
int16_t *X, /* vector to quantize (Q13) */
int16_t n_cb
){
int16_t i, j;
int16_t pos, minindex=0;
int16_t tmp;
int32_t dist, mindist;
pos = 0;
mindist = WEBRTC_SPL_WORD32_MAX; /* start value */
/* Find the codebook with the lowest square distance */
for (j = 0; j < n_cb; j++) {
tmp = X[0] - CB[pos];
dist = WEBRTC_SPL_MUL_16_16(tmp, tmp);
for (i = 1; i < 3; i++) {
tmp = X[i] - CB[pos + i];
dist += WEBRTC_SPL_MUL_16_16(tmp, tmp);
}
if (dist < mindist) {
mindist = dist;
minindex = j;
}
pos += 3;
}
/* Store the quantized codebook and the index */
for (i = 0; i < 3; i++) {
Xq[i] = CB[minindex*3 + i];
}
*index = minindex;
}
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