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-rw-r--r--libSBRenc/src/env_est.cpp20
1 files changed, 13 insertions, 7 deletions
diff --git a/libSBRenc/src/env_est.cpp b/libSBRenc/src/env_est.cpp
index 9423f27..a9a7881 100644
--- a/libSBRenc/src/env_est.cpp
+++ b/libSBRenc/src/env_est.cpp
@@ -536,13 +536,18 @@ mhLoweringEnergy(FIXP_DBL nrg, INT M)
\return void
****************************************************************************/
-static FIXP_DBL
-nmhLoweringEnergy(FIXP_DBL nrg, FIXP_DBL nrgSum, INT M)
+static FIXP_DBL nmhLoweringEnergy(
+ FIXP_DBL nrg,
+ const FIXP_DBL nrgSum,
+ const INT nrgSum_scale,
+ const INT M
+ )
{
if (nrg>FL2FXCONST_DBL(0)) {
int sc=0;
/* gain = nrgSum / (nrg*(M+1)) */
FIXP_DBL gain = fMult(fDivNorm(nrgSum, nrg, &sc), GetInvInt(M+1));
+ sc += nrgSum_scale;
/* reduce nrg if gain smaller 1.f */
if ( !((sc>=0) && ( gain > ((FIXP_DBL)MAXVAL_DBL>>sc) )) ) {
@@ -616,6 +621,7 @@ calculateSbrEnvelope (FIXP_DBL **RESTRICT YBufferLeft, /*! energy buffer left *
FIXP_DBL pNrgLeft[QMF_MAX_TIME_SLOTS];
FIXP_DBL pNrgRight[QMF_MAX_TIME_SLOTS];
+ int envNrg_scale;
FIXP_DBL envNrgLeft = FL2FXCONST_DBL(0.0f);
FIXP_DBL envNrgRight = FL2FXCONST_DBL(0.0f);
int missingHarmonic[QMF_MAX_TIME_SLOTS];
@@ -625,6 +631,7 @@ calculateSbrEnvelope (FIXP_DBL **RESTRICT YBufferLeft, /*! energy buffer left *
stop_pos = timeStep * frame_info->borders[i + 1];
freq_res = frame_info->freqRes[i];
no_of_bands = h_con->nSfb[freq_res];
+ envNrg_scale = DFRACT_BITS-fNormz((FIXP_DBL)no_of_bands);
if (i == short_env) {
stop_pos -= fixMax(2, timeStep); /* consider at least 2 QMF slots less for short envelopes (envelopes just before transients) */
@@ -762,9 +769,8 @@ calculateSbrEnvelope (FIXP_DBL **RESTRICT YBufferLeft, /*! energy buffer left *
/* save energies */
pNrgLeft[j] = nrgLeft;
pNrgRight[j] = nrgRight;
- envNrgLeft += nrgLeft;
- envNrgRight += nrgRight;
-
+ envNrgLeft += (nrgLeft>>envNrg_scale);
+ envNrgRight += (nrgRight>>envNrg_scale);
} /* j */
for (j = 0; j < no_of_bands; j++) {
@@ -777,9 +783,9 @@ calculateSbrEnvelope (FIXP_DBL **RESTRICT YBufferLeft, /*! energy buffer left *
if(!missingHarmonic[j] && h_sbr->fLevelProtect) {
/* in case of missing energy in base band,
reduce reference energy to prevent overflows in decoder output */
- nrgLeft = nmhLoweringEnergy(nrgLeft, envNrgLeft, no_of_bands);
+ nrgLeft = nmhLoweringEnergy(nrgLeft, envNrgLeft, envNrg_scale, no_of_bands);
if (stereoMode == SBR_COUPLING) {
- nrgRight = nmhLoweringEnergy(nrgRight, envNrgRight, no_of_bands);
+ nrgRight = nmhLoweringEnergy(nrgRight, envNrgRight, envNrg_scale, no_of_bands);
}
}