diff options
Diffstat (limited to 'libSBRenc/src/env_est.cpp')
| -rw-r--r-- | libSBRenc/src/env_est.cpp | 20 |
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); } } |