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/******************************** MPEG Audio Encoder **************************
(C) copyright Fraunhofer IIS (1999)
All Rights Reserved
Please be advised that this software and/or program delivery is
Confidential Information of Fraunhofer and subject to and covered by the
Fraunhofer IIS Software Evaluation Agreement
between Google Inc. and Fraunhofer
effective and in full force since March 1, 2012.
You may use this software and/or program only under the terms and
conditions described in the above mentioned Fraunhofer IIS Software
Evaluation Agreement. Any other and/or further use requires a separate agreement.
$Id$
Initial author: M.Werner
contents/description: Pre echo control
This software and/or program is protected by copyright law and international
treaties. Any reproduction or distribution of this software and/or program,
or any portion of it, may result in severe civil and criminal penalties, and
will be prosecuted to the maximum extent possible under law.
******************************************************************************/
#include "pre_echo_control.h"
#include "psy_configuration.h"
void FDKaacEnc_InitPreEchoControl(FIXP_DBL *RESTRICT pbThresholdNm1,
INT *calcPreEcho,
INT numPb,
FIXP_DBL *RESTRICT sfbPcmQuantThreshold,
INT *mdctScalenm1)
{
*mdctScalenm1 = PCM_QUANT_THR_SCALE>>1;
FDKmemcpy(pbThresholdNm1, sfbPcmQuantThreshold, numPb*sizeof(FIXP_DBL));
*calcPreEcho = 1;
}
void FDKaacEnc_PreEchoControl(FIXP_DBL *RESTRICT pbThresholdNm1,
INT calcPreEcho,
INT numPb,
INT maxAllowedIncreaseFactor,
FIXP_SGL minRemainingThresholdFactor,
FIXP_DBL *RESTRICT pbThreshold,
INT mdctScale,
INT *mdctScalenm1)
{
int i;
FIXP_DBL tmpThreshold1, tmpThreshold2;
int scaling;
/* If lastWindowSequence in previous frame was start- or stop-window,
skip preechocontrol calculation */
if (calcPreEcho==0) {
/* copy thresholds to internal memory */
FDKmemcpy(pbThresholdNm1, pbThreshold, numPb*sizeof(FIXP_DBL));
*mdctScalenm1 = mdctScale;
return;
}
if ( mdctScale > *mdctScalenm1 ) {
/* if current thresholds are downscaled more than the ones from the last block */
scaling = 2*(mdctScale-*mdctScalenm1);
for(i = 0; i < numPb; i++) {
/* multiplication with return data type fract ist equivalent to int multiplication */
FDK_ASSERT(scaling>=0);
tmpThreshold1 = maxAllowedIncreaseFactor * (pbThresholdNm1[i]>>scaling);
tmpThreshold2 = fMult(minRemainingThresholdFactor, pbThreshold[i]);
FIXP_DBL tmp = pbThreshold[i];
/* copy thresholds to internal memory */
pbThresholdNm1[i] = tmp;
tmp = fixMin(tmp, tmpThreshold1);
pbThreshold[i] = fixMax(tmp, tmpThreshold2);
}
}
else {
/* if thresholds of last block are more downscaled than the current ones */
scaling = 2*(*mdctScalenm1-mdctScale);
for(i = 0; i < numPb; i++) {
/* multiplication with return data type fract ist equivalent to int multiplication */
tmpThreshold1 = (maxAllowedIncreaseFactor>>1) * pbThresholdNm1[i];
tmpThreshold2 = fMult(minRemainingThresholdFactor, pbThreshold[i]);
/* copy thresholds to internal memory */
pbThresholdNm1[i] = pbThreshold[i];
FDK_ASSERT(scaling>=0);
if((pbThreshold[i]>>(scaling+1)) > tmpThreshold1) {
pbThreshold[i] = tmpThreshold1<<(scaling+1);
}
pbThreshold[i] = fixMax(pbThreshold[i], tmpThreshold2);
}
}
*mdctScalenm1 = mdctScale;
}
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