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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_Refiner.c
******************************************************************/
#include "modules/audio_coding/codecs/ilbc/refiner.h"
#include "modules/audio_coding/codecs/ilbc/constants.h"
#include "modules/audio_coding/codecs/ilbc/enh_upsample.h"
#include "modules/audio_coding/codecs/ilbc/my_corr.h"
/*----------------------------------------------------------------*
* find segment starting near idata+estSegPos that has highest
* correlation with idata+centerStartPos through
* idata+centerStartPos+ENH_BLOCKL-1 segment is found at a
* resolution of ENH_UPSO times the original of the original
* sampling rate
*---------------------------------------------------------------*/
void WebRtcIlbcfix_Refiner(
size_t *updStartPos, /* (o) updated start point (Q-2) */
int16_t *idata, /* (i) original data buffer */
size_t idatal, /* (i) dimension of idata */
size_t centerStartPos, /* (i) beginning center segment */
size_t estSegPos, /* (i) estimated beginning other segment (Q-2) */
int16_t *surround, /* (i/o) The contribution from this sequence
summed with earlier contributions */
int16_t gain /* (i) Gain to use for this sequence */
){
size_t estSegPosRounded, searchSegStartPos, searchSegEndPos, corrdim;
size_t tloc, tloc2, i;
int32_t maxtemp, scalefact;
int16_t *filtStatePtr, *polyPtr;
/* Stack based */
int16_t filt[7];
int32_t corrVecUps[ENH_CORRDIM*ENH_UPS0];
int32_t corrVecTemp[ENH_CORRDIM];
int16_t vect[ENH_VECTL];
int16_t corrVec[ENH_CORRDIM];
/* defining array bounds */
estSegPosRounded = (estSegPos - 2) >> 2;
searchSegStartPos =
(estSegPosRounded < ENH_SLOP) ? 0 : (estSegPosRounded - ENH_SLOP);
searchSegEndPos = estSegPosRounded + ENH_SLOP;
if ((searchSegEndPos + ENH_BLOCKL) >= idatal) {
searchSegEndPos = idatal - ENH_BLOCKL - 1;
}
corrdim = searchSegEndPos + 1 - searchSegStartPos;
/* compute upsampled correlation and find
location of max */
WebRtcIlbcfix_MyCorr(corrVecTemp, idata + searchSegStartPos,
corrdim + ENH_BLOCKL - 1, idata + centerStartPos,
ENH_BLOCKL);
/* Calculate the rescaling factor for the correlation in order to
put the correlation in a int16_t vector instead */
maxtemp = WebRtcSpl_MaxAbsValueW32(corrVecTemp, corrdim);
scalefact = WebRtcSpl_GetSizeInBits(maxtemp) - 15;
if (scalefact > 0) {
for (i = 0; i < corrdim; i++) {
corrVec[i] = (int16_t)(corrVecTemp[i] >> scalefact);
}
} else {
for (i = 0; i < corrdim; i++) {
corrVec[i] = (int16_t)corrVecTemp[i];
}
}
/* In order to guarantee that all values are initialized */
for (i = corrdim; i < ENH_CORRDIM; i++) {
corrVec[i] = 0;
}
/* Upsample the correlation */
WebRtcIlbcfix_EnhUpsample(corrVecUps, corrVec);
/* Find maximum */
tloc = WebRtcSpl_MaxIndexW32(corrVecUps, ENH_UPS0 * corrdim);
/* make vector can be upsampled without ever running outside
bounds */
*updStartPos = searchSegStartPos * 4 + tloc + 4;
tloc2 = (tloc + 3) >> 2;
/* initialize the vector to be filtered, stuff with zeros
when data is outside idata buffer */
if (ENH_FL0 > (searchSegStartPos + tloc2)) {
const size_t st = ENH_FL0 - searchSegStartPos - tloc2;
WebRtcSpl_MemSetW16(vect, 0, st);
WEBRTC_SPL_MEMCPY_W16(&vect[st], idata, ENH_VECTL - st);
} else {
const size_t st = searchSegStartPos + tloc2 - ENH_FL0;
if ((st + ENH_VECTL) > idatal) {
const size_t en = st + ENH_VECTL - idatal;
WEBRTC_SPL_MEMCPY_W16(vect, &idata[st], ENH_VECTL - en);
WebRtcSpl_MemSetW16(&vect[ENH_VECTL - en], 0, en);
} else {
WEBRTC_SPL_MEMCPY_W16(vect, &idata[st], ENH_VECTL);
}
}
/* compute the segment (this is actually a convolution) */
filtStatePtr = filt + 6;
polyPtr = (int16_t*)WebRtcIlbcfix_kEnhPolyPhaser[tloc2 * ENH_UPS0 - tloc];
for (i = 0; i < 7; i++) {
*filtStatePtr-- = *polyPtr++;
}
WebRtcSpl_FilterMAFastQ12(&vect[6], vect, filt, ENH_FLO_MULT2_PLUS1,
ENH_BLOCKL);
/* Add the contribution from this vector (scaled with gain) to the total
surround vector */
WebRtcSpl_AddAffineVectorToVector(surround, vect, gain, 32768, 16,
ENH_BLOCKL);
return;
}