1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
|
/*
* This file is part of AtracDEnc.
*
* AtracDEnc is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* AtracDEnc is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with AtracDEnc; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "atrac1_dequantiser.h"
#include <string.h>
namespace NAtracDEnc {
namespace NAtrac1 {
using namespace NBitStream;
TAtrac1Dequantiser::TAtrac1Dequantiser() {
}
void TAtrac1Dequantiser::Dequant(TBitStream* stream, const TBlockSize& bs, float specs[512]) {
uint32_t wordLens[TAtrac1Data::MaxBfus];
uint32_t idScaleFactors[TAtrac1Data::MaxBfus];
const uint32_t numBFUs = TAtrac1Data::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 < TAtrac1Data::MaxBfus; i++) {
wordLens[i] = idScaleFactors[i] = 0;
}
for (uint32_t bandNum = 0; bandNum < TAtrac1Data::NumQMF; bandNum++) {
for (uint32_t bfuNum = TAtrac1Data::BlocksPerBand[bandNum]; bfuNum < TAtrac1Data::BlocksPerBand[bandNum + 1]; bfuNum++) {
const uint32_t numSpecs = TAtrac1Data::SpecsPerBlock[bfuNum];
const uint32_t wordLen = !!wordLens[bfuNum] + wordLens[bfuNum];
const float scaleFactor = TAtrac1Data::ScaleTable[idScaleFactors[bfuNum]];
const uint32_t startPos = bs.LogCount[bandNum] ?
TAtrac1Data::SpecsStartShort[bfuNum] : TAtrac1Data::SpecsStartLong[bfuNum];
if (wordLen) {
float maxQuant = 1.0 / (float)((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(float));
}
}
}
}
} //namespace NAtrac1
} //namespace NAtracDEnc
|
