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 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 = 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
