public BigHuffmanTree(BitStream bs, int allocSize)
{
_bs = bs;
uint bit = _bs.GetBit();
if (bit == 0)
{
_tree = new uint[1];
_tree[0] = 0;
_last[0] = _last[1] = _last[2] = 0;
return;
}
for (uint i = 0; i < 256; ++i)
{
_prefixtree[i] = _prefixlength[i] = 0;
}
_loBytes = new SmallHuffmanTree(_bs);
_hiBytes = new SmallHuffmanTree(_bs);
_markers[0] = _bs.GetBits(16);
_markers[1] = _bs.GetBits(16);
_markers[2] = _bs.GetBits(16);
_last[0] = _last[1] = _last[2] = 0xffffffff;
_treeSize = 0;
_tree = new uint[allocSize / 4];
DecodeTree(0, 0);
bit = _bs.GetBit();
Debug.Assert(bit == 0);
for (uint i = 0; i < 3; ++i)
{
if (_last[i] == 0xffffffff)
{
_last[i] = _treeSize;
_tree[_treeSize++] = 0;
}
}
}
public BigHuffmanTree(BitStream bs, int allocSize)
{
_bs = bs;
uint bit = _bs.GetBit();
if (bit == 0)
{
_tree = new uint[1];
_tree[0] = 0;
_last[0] = _last[1] = _last[2] = 0;
return;
}
for (uint i = 0; i < 256; ++i)
_prefixtree[i] = _prefixlength[i] = 0;
_loBytes = new SmallHuffmanTree(_bs);
_hiBytes = new SmallHuffmanTree(_bs);
_markers[0] = _bs.GetBits(16);
_markers[1] = _bs.GetBits(16);
_markers[2] = _bs.GetBits(16);
_last[0] = _last[1] = _last[2] = 0xffffffff;
_treeSize = 0;
_tree = new uint[allocSize / 4];
DecodeTree(0, 0);
bit = _bs.GetBit();
Debug.Assert(bit == 0);
for (uint i = 0; i < 3; ++i)
{
if (_last[i] == 0xffffffff)
{
_last[i] = _treeSize;
_tree[_treeSize++] = 0;
}
}
}
public void QueueCompressedBuffer(byte[] buffer, int bufferSize, int unpackedSize)
{
using (var ms = new MemoryStream(buffer, 0, bufferSize))
{
var audioBS = BitStream.Create8Lsb(ms);
bool dataPresent = audioBS.GetBit() != 0;
if (!dataPresent)
return;
bool isStereo = audioBS.GetBit() != 0;
Debug.Assert(isStereo == _audioInfo.isStereo);
bool is16Bits = audioBS.GetBit() != 0;
Debug.Assert(is16Bits == _audioInfo.is16Bits);
int numBytes = 1 * (isStereo ? 2 : 1) * (is16Bits ? 2 : 1);
byte[] unpackedBuffer = new byte[unpackedSize];
var curPointer = 0;
var curPos = 0;
SmallHuffmanTree[] audioTrees = new SmallHuffmanTree[4];
for (int k = 0; k < numBytes; k++)
audioTrees[k] = new SmallHuffmanTree(audioBS);
// Base values, stored as big endian
int[] bases = new int[2];
if (isStereo)
{
if (is16Bits)
{
bases[1] = ScummHelper.SwapBytes((ushort)audioBS.GetBits(16));
}
else
{
bases[1] = (int)audioBS.GetBits(8);
}
}
if (is16Bits)
{
bases[0] = ScummHelper.SwapBytes((ushort)audioBS.GetBits(16));
}
else
{
bases[0] = (int)audioBS.GetBits(8);
}
// The bases are the first samples, too
for (int i = 0;
i < (isStereo ? 2 : 1);
i++, curPointer += (is16Bits ? 2 : 1), curPos += (is16Bits ? 2 : 1))
{
if (is16Bits)
unpackedBuffer.WriteUInt16BigEndian(curPointer, (ushort)bases[i]);
else
unpackedBuffer[curPointer] = (byte)((bases[i] & 0xFF) ^ 0x80);
}
// Next follow the deltas, which are added to the corresponding base values and
// are stored as little endian
// We store the unpacked bytes in big endian format
while (curPos < unpackedSize)
{
// If the sample is stereo, the data is stored for the left and right channel, respectively
// (the exact opposite to the base values)
if (!is16Bits)
{
for (int k = 0; k < (isStereo ? 2 : 1); k++)
{
sbyte delta = (sbyte)((short)audioTrees[k].GetCode(audioBS));
bases[k] = (bases[k] + delta) & 0xFF;
unpackedBuffer[curPointer++] = (byte)(bases[k] ^ 0x80);
curPos++;
}
}
else
{
for (int k = 0; k < (isStereo ? 2 : 1); k++)
{
byte lo = (byte)audioTrees[k * 2].GetCode(audioBS);
byte hi = (byte)audioTrees[k * 2 + 1].GetCode(audioBS);
bases[k] += (short)(lo | (hi << 8));
unpackedBuffer.WriteUInt16BigEndian(curPointer, (ushort)bases[k]);
curPointer += 2;
curPos += 2;
}
}
}
QueuePCM(unpackedBuffer, unpackedSize);
}
}
public void QueueCompressedBuffer(byte[] buffer, int bufferSize, int unpackedSize)
{
using (var ms = new MemoryStream(buffer, 0, bufferSize))
{
var audioBS = BitStream.Create8Lsb(ms);
bool dataPresent = audioBS.GetBit() != 0;
if (!dataPresent)
{
return;
}
bool isStereo = audioBS.GetBit() != 0;
Debug.Assert(isStereo == _audioInfo.isStereo);
bool is16Bits = audioBS.GetBit() != 0;
Debug.Assert(is16Bits == _audioInfo.is16Bits);
int numBytes = 1 * (isStereo ? 2 : 1) * (is16Bits ? 2 : 1);
byte[] unpackedBuffer = new byte[unpackedSize];
var curPointer = 0;
var curPos = 0;
SmallHuffmanTree[] audioTrees = new SmallHuffmanTree[4];
for (int k = 0; k < numBytes; k++)
{
audioTrees[k] = new SmallHuffmanTree(audioBS);
}
// Base values, stored as big endian
int[] bases = new int[2];
if (isStereo)
{
if (is16Bits)
{
bases[1] = ScummHelper.SwapBytes((ushort)audioBS.GetBits(16));
}
else
{
bases[1] = (int)audioBS.GetBits(8);
}
}
if (is16Bits)
{
bases[0] = ScummHelper.SwapBytes((ushort)audioBS.GetBits(16));
}
else
{
bases[0] = (int)audioBS.GetBits(8);
}
// The bases are the first samples, too
for (int i = 0;
i < (isStereo ? 2 : 1);
i++, curPointer += (is16Bits ? 2 : 1), curPos += (is16Bits ? 2 : 1))
{
if (is16Bits)
{
unpackedBuffer.WriteUInt16BigEndian(curPointer, (ushort)bases[i]);
}
else
{
unpackedBuffer[curPointer] = (byte)((bases[i] & 0xFF) ^ 0x80);
}
}
// Next follow the deltas, which are added to the corresponding base values and
// are stored as little endian
// We store the unpacked bytes in big endian format
while (curPos < unpackedSize)
{
// If the sample is stereo, the data is stored for the left and right channel, respectively
// (the exact opposite to the base values)
if (!is16Bits)
{
for (int k = 0; k < (isStereo ? 2 : 1); k++)
{
sbyte delta = (sbyte)((short)audioTrees[k].GetCode(audioBS));
bases[k] = (bases[k] + delta) & 0xFF;
unpackedBuffer[curPointer++] = (byte)(bases[k] ^ 0x80);
curPos++;
}
}
else
{
for (int k = 0; k < (isStereo ? 2 : 1); k++)
{
byte lo = (byte)audioTrees[k * 2].GetCode(audioBS);
byte hi = (byte)audioTrees[k * 2 + 1].GetCode(audioBS);
bases[k] += (short)(lo | (hi << 8));
unpackedBuffer.WriteUInt16BigEndian(curPointer, (ushort)bases[k]);
curPointer += 2;
curPos += 2;
}
}
}
QueuePCM(unpackedBuffer, unpackedSize);
}
}
