private static void storeTree(ref EncodeNode node, Symbol[] sym, ref BitStream stream, uint code, uint bits)
{
uint symbolIndex;
if (node.Symbol >= 0)
{
writeBits(ref stream, 1, 1);
writeBits(ref stream, (uint)node.Symbol, 8);
for (symbolIndex = 0; symbolIndex < 256; ++symbolIndex)
{
if (sym[symbolIndex].Sym == node.Symbol)
{
break;
}
}
sym[symbolIndex].Code = code;
sym[symbolIndex].Bits = bits;
return;
}
else
{
writeBits(ref stream, 0, 1);
}
storeTree(ref node.ChildA, sym, ref stream, (code << 1) + 0, bits + 1);
storeTree(ref node.ChildB, sym, ref stream, (code << 1) + 1, bits + 1);
}
private static void makeTree(Symbol[] sym, ref BitStream stream)
{
EncodeNode[] nodes = new EncodeNode[MAX_TREE_NODES];
for (int counter = 0; counter < nodes.Length; ++counter)
{
nodes[counter] = new EncodeNode();
}
EncodeNode node1, node2, root;
uint i, numSymbols = 0, nodesLeft, nextIndex;
for (i = 0; i < 256; ++i)
{
if (sym[i].Count > 0)
{
nodes[numSymbols].Symbol = sym[i].Sym;
nodes[numSymbols].Count = (int)sym[i].Count;
nodes[numSymbols].ChildA = null;
nodes[numSymbols].ChildB = null;
++numSymbols;
}
}
root = null;
nodesLeft = numSymbols;
nextIndex = numSymbols;
while (nodesLeft > 1)
{
node1 = null;
node2 = null;
for (i = 0; i < nextIndex; ++i)
{
if (nodes[i].Count > 0)
{
if (node1 == null || (nodes[i].Count <= node1.Count))
{
node2 = node1;
node1 = nodes[i];
}
else if (node2 == null || (nodes[i].Count <= node2.Count))
{
node2 = nodes[i];
}
}
}
root = nodes[nextIndex];
root.ChildA = node1;
root.ChildB = node2;
root.Count = node1.Count + node2.Count;
root.Symbol = -1;
node1.Count = 0;
node2.Count = 0;
++nextIndex;
--nodesLeft;
}
if (root != null)
{
storeTree(ref root, sym, ref stream, 0, 0);
}
else
{
root = nodes[0];
storeTree(ref root, sym, ref stream, 0, 1);
}
}
