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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_AbsQuantLoop.c
******************************************************************/
#include "modules/audio_coding/codecs/ilbc/abs_quant_loop.h"
#include "modules/audio_coding/codecs/ilbc/constants.h"
#include "modules/audio_coding/codecs/ilbc/defines.h"
#include "modules/audio_coding/codecs/ilbc/sort_sq.h"
void WebRtcIlbcfix_AbsQuantLoop(int16_t *syntOutIN, int16_t *in_weightedIN,
int16_t *weightDenumIN, size_t *quantLenIN,
int16_t *idxVecIN ) {
size_t k1, k2;
int16_t index;
int32_t toQW32;
int32_t toQ32;
int16_t tmp16a;
int16_t xq;
int16_t *syntOut = syntOutIN;
int16_t *in_weighted = in_weightedIN;
int16_t *weightDenum = weightDenumIN;
size_t *quantLen = quantLenIN;
int16_t *idxVec = idxVecIN;
for(k1=0;k1<2;k1++) {
for(k2=0;k2<quantLen[k1];k2++){
/* Filter to get the predicted value */
WebRtcSpl_FilterARFastQ12(
syntOut, syntOut,
weightDenum, LPC_FILTERORDER+1, 1);
/* the quantizer */
toQW32 = (int32_t)(*in_weighted) - (int32_t)(*syntOut);
toQ32 = (((int32_t)toQW32)<<2);
if (toQ32 > 32767) {
toQ32 = (int32_t) 32767;
} else if (toQ32 < -32768) {
toQ32 = (int32_t) -32768;
}
/* Quantize the state */
if (toQW32<(-7577)) {
/* To prevent negative overflow */
index=0;
} else if (toQW32>8151) {
/* To prevent positive overflow */
index=7;
} else {
/* Find the best quantization index
(state_sq3Tbl is in Q13 and toQ is in Q11)
*/
WebRtcIlbcfix_SortSq(&xq, &index,
(int16_t)toQ32,
WebRtcIlbcfix_kStateSq3, 8);
}
/* Store selected index */
(*idxVec++) = index;
/* Compute decoded sample and update of the prediction filter */
tmp16a = ((WebRtcIlbcfix_kStateSq3[index] + 2 ) >> 2);
*syntOut = (int16_t) (tmp16a + (int32_t)(*in_weighted) - toQW32);
syntOut++; in_weighted++;
}
/* Update perceptual weighting filter at subframe border */
weightDenum += 11;
}
}