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/*
** Copyright 2003-2010, VisualOn, Inc.
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
/*******************************************************************************
File: pre_echo_control.c
Content: Pre echo control functions
*******************************************************************************/
#include "basic_op.h"
#include "oper_32b.h"
#include "oper_32b.h"
#include "pre_echo_control.h"
/*****************************************************************************
*
* function name:InitPreEchoControl
* description: init pre echo control parameter
*
*****************************************************************************/
void InitPreEchoControl(Word32 *pbThresholdNm1,
Word16 numPb,
Word32 *pbThresholdQuiet)
{
Word16 pb;
for(pb=0; pb<numPb; pb++) {
pbThresholdNm1[pb] = pbThresholdQuiet[pb];
}
}
/*****************************************************************************
*
* function name:PreEchoControl
* description: update shreshold to avoid pre echo
* thr(n) = max(rpmin*thrq(n), min(thrq(n), rpelev*thrq1(n)))
*
*
*****************************************************************************/
void PreEchoControl(Word32 *pbThresholdNm1,
Word16 numPb,
Word32 maxAllowedIncreaseFactor,
Word16 minRemainingThresholdFactor,
Word32 *pbThreshold,
Word16 mdctScale,
Word16 mdctScalenm1)
{
Word32 i;
Word32 tmpThreshold1, tmpThreshold2;
Word32 scaling;
/* maxAllowedIncreaseFactor is hard coded to 2 */
(void)maxAllowedIncreaseFactor;
scaling = ((mdctScale - mdctScalenm1) << 1);
if ( scaling > 0 ) {
for(i = 0; i < numPb; i++) {
tmpThreshold1 = pbThresholdNm1[i] >> (scaling-1);
tmpThreshold2 = L_mpy_ls(pbThreshold[i], minRemainingThresholdFactor);
/* copy thresholds to internal memory */
pbThresholdNm1[i] = pbThreshold[i];
if(pbThreshold[i] > tmpThreshold1) {
pbThreshold[i] = tmpThreshold1;
}
if(tmpThreshold2 > pbThreshold[i]) {
pbThreshold[i] = tmpThreshold2;
}
}
}
else {
scaling = -scaling;
for(i = 0; i < numPb; i++) {
tmpThreshold1 = pbThresholdNm1[i] << 1;
tmpThreshold2 = L_mpy_ls(pbThreshold[i], minRemainingThresholdFactor);
/* copy thresholds to internal memory */
pbThresholdNm1[i] = pbThreshold[i];
if(((pbThreshold[i] >> scaling) > tmpThreshold1)) {
pbThreshold[i] = tmpThreshold1 << scaling;
}
if(tmpThreshold2 > pbThreshold[i]) {
pbThreshold[i] = tmpThreshold2;
}
}
}
}
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