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M/S bit allocation

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This commit is contained in:
Christian R. Helmrich
2020-04-12 01:00:23 +02:00
parent 9f82a8a5bf
commit 42b912d3c4
2 changed files with 64 additions and 16 deletions
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79
src/lib/stereoProcessing.cpp
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@@ -68,6 +68,10 @@ unsigned StereoProcessor::applyFullFrameMatrix (int32_t* const mdctSpectrum1, in
const uint16_t sfbWidth = grpOff[sfb + 1] - sfbStart;
int32_t* sfbMdct1 = &mdctSpectrum1[sfbStart];
int32_t* sfbMdct2 = &mdctSpectrum2[sfbStart];
#if SP_MDST_PRED
int32_t* sfbMdst1 = &mdstSpectrum1[sfbStart];
int32_t* sfbMdst2 = &mdstSpectrum2[sfbStart];
#endif
uint64_t sumAbsValM = 0, sumAbsValS = 0;
double sfbTempVar;
@@ -94,6 +98,10 @@ unsigned StereoProcessor::applyFullFrameMatrix (int32_t* const mdctSpectrum1, in
*(sfbMdct1++) = dmixReM;
*(sfbMdct2++) = dmixReS;
#if SP_MDST_PRED
*(sfbMdst1++) = dmixImM;
*(sfbMdst2++) = dmixImS;
#endif
sfbNext1++; prevReM = dmixReM;
sfbNext2++; prevReS = dmixReS;
}
@@ -107,13 +115,18 @@ unsigned StereoProcessor::applyFullFrameMatrix (int32_t* const mdctSpectrum1, in
*sfbMdct1 = dmixReM;
*sfbMdct2 = dmixReS;
#if SP_MDST_PRED
*sfbMdst1 = 0;
*sfbMdst2 = 0;
#endif
}
}
else // complex data, both MDCTs and MDSTs are available
{
#if !SP_MDST_PRED
int32_t* sfbMdst1 = &mdstSpectrum1[sfbStart];
int32_t* sfbMdst2 = &mdstSpectrum2[sfbStart];
#endif
for (uint16_t s = sfbWidth; s > 0; s--)
{
const int32_t dmixReM = int32_t (((int64_t) *sfbMdct1 + (int64_t) *sfbMdct2 + 1) >> 1);
@@ -161,14 +174,36 @@ unsigned StereoProcessor::applyFullFrameMatrix (int32_t* const mdctSpectrum1, in
const uint16_t width = grpOff[sfb + 1] - offEv;
const int32_t* mdctA = (alterPredDir ? &mdctSpectrum2[offEv] : &mdctSpectrum1[offEv]);
const int32_t* mdctB = (alterPredDir ? &mdctSpectrum1[offEv] : &mdctSpectrum2[offEv]);
int64_t sumPrdRefRes = 0, sumPrdRefRef = SP_EPS; // stabilizes the division below
#if SP_MDST_PRED
const int32_t* mdstA = (alterPredDir ? &mdstSpectrum2[offEv] : &mdstSpectrum1[offEv]);
const int32_t* mdstB = (alterPredDir ? &mdstSpectrum1[offEv] : &mdstSpectrum2[offEv]);
int64_t sumPrdImAReB = 0, sumPrdImAImA = SP_EPS;
#endif
int64_t sumPrdReAReB = 0, sumPrdReAReA = SP_EPS; // stabilizes the division below
double d, alphaLimit = 1.5; // max alpha_q magnitude
bool nonZeroPredCoef = false;
#if SP_MDST_PRED
for (uint16_t s = width; s > 0; s--, mdctA++, mdctB++, mdstA++, mdstB++)
{
const int64_t prdReAReA = ((int64_t) *mdctA * (int64_t) *mdctA + SA_BW) >> (SA_BW_SHIFT + 1);
const int64_t prdImAImA = ((int64_t) *mdstA * (int64_t) *mdstA + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdReAReB += ((int64_t) *mdctA * (int64_t) *mdctB + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdReAReA += prdReAReA;
sumPrdImAReB += ((int64_t) *mdstA * (int64_t) *mdctB + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdImAImA += prdImAImA;
// add complex conjugate part, increases stability
sumPrdReAReB += ((int64_t) *mdstA * (int64_t) *mdstB + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdReAReA += prdImAImA;
sumPrdImAReB -= ((int64_t) *mdctA * (int64_t) *mdstB + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdImAImA += prdReAReA;
}
#else
for (uint16_t s = width; s > 0; s--, mdctA++, mdctB++)
{
sumPrdRefRes += ((int64_t) *mdctA * (int64_t) *mdctB + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdRefRef += ((int64_t) *mdctA * (int64_t) *mdctA + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdReAReB += ((int64_t) *mdctA * (int64_t) *mdctB + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdReAReA += ((int64_t) *mdctA * (int64_t) *mdctA + SA_BW) >> (SA_BW_SHIFT + 1);
}
if (realOnlyCalc) // real data, only MDCTs available
{
@@ -190,8 +225,8 @@ unsigned StereoProcessor::applyFullFrameMatrix (int32_t* const mdctSpectrum1, in
const int64_t mdstA = ((int64_t) *(nextA++) - (int64_t) *(mdctA++)) >> 1; // estimate, see also
const int64_t mdstB = ((int64_t) *(nextB++) - (int64_t) *(mdctB++)) >> 1; // getMeanAbsValues()
sumPrdRefRes += (mdstA * mdstB + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdRefRef += (mdstA * mdstA + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdReAReB += (mdstA * mdstB + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdReAReA += (mdstA * mdstA + SA_BW) >> (SA_BW_SHIFT + 1);
}
if (sfb + 1 < numSwbFrame) // process final sample
{
@@ -199,8 +234,8 @@ unsigned StereoProcessor::applyFullFrameMatrix (int32_t* const mdctSpectrum1, in
const int64_t mdstA = ((((int64_t) *nextB + *nextA * msSgn + 1) >> 1) - (int64_t) *mdctA) >> 1;
const int64_t mdstB = ((((int64_t) *nextA - *nextB * msSgn + 1) >> 1) - (int64_t) *mdctB) >> 1;
sumPrdRefRes += (mdstA * mdstB + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdRefRef += (mdstA * mdstA + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdReAReB += (mdstA * mdstB + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdReAReA += (mdstA * mdstA + SA_BW) >> (SA_BW_SHIFT + 1);
}
}
else // complex data, both MDCTs and MDSTs available
@@ -210,27 +245,37 @@ unsigned StereoProcessor::applyFullFrameMatrix (int32_t* const mdctSpectrum1, in
for (uint16_t s = width; s > 0; s--, mdstA++, mdstB++)
{
sumPrdRefRes += ((int64_t) *mdstA * (int64_t) *mdstB + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdRefRef += ((int64_t) *mdstA * (int64_t) *mdstA + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdReAReB += ((int64_t) *mdstA * (int64_t) *mdstB + SA_BW) >> (SA_BW_SHIFT + 1);
sumPrdReAReA += ((int64_t) *mdstA * (int64_t) *mdstA + SA_BW) >> (SA_BW_SHIFT + 1);
}
}
sfbTempVar = (double) sumPrdRefRes / (double) sumPrdRefRef; // compute alpha_q_re
for (b = sfbIsOdd; b >= 0; b--) // limit alpha_q_re to avoid residual RMS increase
#endif
for (b = sfbIsOdd; b >= 0; b--) // limit alpha_q to prevent residual RMS increases
{
const int idx = sfbEv + b;
d = (alterPredDir ? (double) grpRms1[idx] / __max (SP_EPS, grpRms2[idx]) : (double) grpRms2[idx] / __max (SP_EPS, grpRms1[idx]));
if (alphaLimit > d) alphaLimit = d;
}
sfbTempVar = CLIP_PM (sfbTempVar, alphaLimit);
sfbTempVar = CLIP_PM ((double) sumPrdReAReB / (double) sumPrdReAReA, alphaLimit);
#if SP_OPT_ALPHA_QUANT
b = __max (512, 524 - int32_t (abs (10.0 * sfbTempVar))); // rounding optimization
b = int32_t (10.0 * sfbTempVar + b * (sfbTempVar < 0 ? -0.0009765625 : 0.0009765625));
#else
b = int32_t (10.0 * sfbTempVar + (sfbTempVar < 0 ? -0.5 : 0.5));// nearest integer
#endif
sfbStereoData[sfbEv + numSwbFrame * gr] = uint8_t (b + 16);
sfbStereoData[sfbEv + numSwbFrame * gr] = uint8_t (b + 16); // finished alpha_q_re
#if SP_MDST_PRED
alphaLimit = CLIP_PM ((double) sumPrdImAReB / (double) sumPrdImAImA, alphaLimit);
# if SP_OPT_ALPHA_QUANT
b = __max (512, 524 - int32_t (abs (10.0 * alphaLimit))); // rounding optimization
b = int32_t (10.0 * alphaLimit + b * (alphaLimit < 0 ? -0.0009765625 : 0.0009765625));
# else
b = int32_t (10.0 * alphaLimit + (alphaLimit < 0 ? -0.5 : 0.5));// nearest integer
# endif
if (sfbEv + 1 < numSwbFrame)
sfbStereoData[sfbEv + 1 + numSwbFrame * gr] = uint8_t (b + 16); // init alpha_q_im
#endif
if (!eightShorts && ((offEv & (SA_BW - 1)) == 0) && ((width & (SA_BW - 1)) == 0))
{
@@ -247,7 +292,9 @@ unsigned StereoProcessor::applyFullFrameMatrix (int32_t* const mdctSpectrum1, in
nonZeroPredCoef = true;
}
sfbTempVar *= sfbTempVar; // account for residual RMS reduction due to prediction
#if SP_MDST_PRED
sfbTempVar += alphaLimit * alphaLimit; // including complex prediction by alpha_im
#endif
for (b = sfbIsOdd; b >= 0; b--)
{
const int idx = sfbEv + b;

1
src/lib/stereoProcessing.h
View File

@@ -16,6 +16,7 @@
// constants, experimental macros
#define SP_EPS 1
#define SP_MDST_PRED 1
#define SP_OPT_ALPHA_QUANT 1 // quantize alpha_q minimizing RMS distortion in louder channel
// joint-channel processing class