uint32 BigHuffmanTree::getCode(Common::BitStream &bs) {
byte peek = bs.peekBits(MIN<uint32>(bs.size() - bs.pos(), 8));
uint32 *p = &_tree[_prefixtree[peek]];
bs.skip(_prefixlength[peek]);
while (*p & SMK_NODE) {
if (bs.getBit())
p += (*p) & ~SMK_NODE;
p++;
}
uint32 v = *p;
if (v != _tree[_last[0]]) {
_tree[_last[2]] = _tree[_last[1]];
_tree[_last[1]] = _tree[_last[0]];
_tree[_last[0]] = v;
}
return v;
}
void CodebookLibrary::rebuild(Common::BitStream &bis, size_t size, Common::BitStreamWriter &bos) {
const uint32 id = 0x564342;
const uint16 dimensions = bis.getBits(4);
const uint32 entries = bis.getBits(14);
bos.putBits(id, 24);
bos.putBits(dimensions, 16);
bos.putBits(entries, 24);
const bool ordered = bis.getBit();
bos.putBit(ordered);
if (ordered) {
const uint8 initialLength = bis.getBits(5);
bos.putBits(initialLength, 5);
uint32 currentEntry = 0;
while (currentEntry < entries) {
const size_t bitCount = Common::intLog2(entries - currentEntry) + 1;
const uint32 number = bis.getBits(bitCount);
bos.putBits(number, bitCount);
currentEntry += number;
}
if (currentEntry > entries)
throw Common::Exception("CodebookLibrary::rebuild(): Current entry out of range");
} else {
const uint8 codewordLengthLength = bis.getBits(3);
const bool sparse = bis.getBit();
if ((codewordLengthLength == 0) || (codewordLengthLength > 5))
throw Common::Exception("CodebookLibrary::rebuild(): Nonsense codeword length");
bos.putBit(sparse);
for (size_t i = 0; i < entries; i++) {
bool present = true;
if (sparse) {
present = bis.getBit();
bos.putBit(present);
}
if (present)
bos.putBits(bis.getBits(codewordLengthLength), 5);
}
}
const uint8 lookupType = bis.getBits(1);
bos.putBits(lookupType, 4);
if (lookupType == 0) {
} else if (lookupType == 1) {
const uint32 min = bis.getBits(32);
const uint32 max = bis.getBits(32);
const uint8 valueLength = bis.getBits(4) + 1;
const bool sequenceFlag = bis.getBit();
bos.putBits(min, 32);
bos.putBits(max, 32);
bos.putBits(valueLength - 1, 4);
bos.putBit(sequenceFlag);
const size_t quantVals = bookMapType1QuantVals(entries, dimensions);
for (size_t i = 0; i < quantVals; i++)
bos.putBits(bis.getBits(valueLength), valueLength);
}
if ((size != 0) && (((bis.pos() / 8) + 1) != size ))
throw Common::Exception("CodebookLibrary::rebuild(): Size mismatch: %s != %s",
Common::composeString((bis.pos() / 8) + 1).c_str(),
Common::composeString(size).c_str());
}