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#include "atrac1_dequantiser.h"
#include <string.h>
namespace NAtracDEnc {
namespace NAtrac1 {
using namespace NBitStream;
TAtrac1Dequantiser::TAtrac1Dequantiser() {
}
void TAtrac1Dequantiser::Dequant(TBitStream* stream, const TBlockSize& bs, TFloat specs[512]) {
uint32_t wordLens[MaxBfus];
uint32_t idScaleFactors[MaxBfus];
const uint32_t numBFUs = BfuAmountTab[stream->Read(3)];
stream->Read(2);
stream->Read(3);
for (uint32_t i = 0; i < numBFUs; i++) {
wordLens[i] = stream->Read(4);
}
for (uint32_t i = 0; i < numBFUs; i++) {
idScaleFactors[i] = stream->Read(6);
}
for (uint32_t i = numBFUs; i < MaxBfus; i++) {
wordLens[i] = idScaleFactors[i] = 0;
}
for (uint32_t bandNum = 0; bandNum < NumQMF; bandNum++) {
for (uint32_t bfuNum = BlocksPerBand[bandNum]; bfuNum < BlocksPerBand[bandNum + 1]; bfuNum++) {
const uint32_t numSpecs = SpecsPerBlock[bfuNum];
const uint32_t wordLen = !!wordLens[bfuNum] + wordLens[bfuNum];
const TFloat scaleFactor = ScaleTable[idScaleFactors[bfuNum]];
const uint32_t startPos = bs.LogCount[bandNum] ? SpecsStartShort[bfuNum] : SpecsStartLong[bfuNum];
if (wordLen) {
TFloat maxQuant = 1.0 / (TFloat)((1 << (wordLen - 1)) - 1);
//cout << "BFU ("<< bfuNum << ") :" << "wordLen " << wordLen << " maxQuant " << maxQuant << " scaleFactor " << scaleFactor << " id " << idScaleFactors[bfuNum] << " num Specs " << numSpecs << " short: "<< (int)bs.LogCount[bandNum] << endl;
for (uint32_t i = 0; i < numSpecs; i++ ) {
specs[startPos + i] = scaleFactor * maxQuant * MakeSign(stream->Read(wordLen), wordLen);
}
} else {
memset(&specs[startPos], 0, numSpecs * sizeof(TFloat));
}
}
}
}
} //namespace NAtrac1
} //namespace NAtracDEnc
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