static public void DecompressGCZ(Stream source, Stream target, int length, int decompLength)
{
BemaniLZSS2Properties props = new BemaniLZSS2Properties();
props.ringBufferOffset = 0xFFE;
props.ringBufferSize = 0x1000;
props.type = BemaniLZSS2Type.GCZ;
Decompress(source, target, length, decompLength, props);
}
static public void Decompress(Stream source, Stream target, int length, int decompLength, BemaniLZSS2Properties props)
{
byte[] ring = new byte[props.ringBufferSize];
int ring_pos = props.ringBufferOffset;
int chunk_offset;
int chunk_length;
int control_word = 1;
int controlBitsLeft = 0;
int controlBitMask = 0x1;
byte cmd1;
byte cmd2;
byte data;
if (decompLength <= 0)
{
decompLength = int.MaxValue;
}
BinaryReaderEx sourceReader = new BinaryReaderEx(source);
BinaryWriterEx writer = new BinaryWriterEx(target);
using (MemoryStream mem = new MemoryStream(sourceReader.ReadBytes(length)))
{
BinaryReaderEx reader = new BinaryReaderEx(mem);
while (decompLength > 0 && length > 0)
{
if (controlBitsLeft == 0)
{
/* Read a control byte */
control_word = reader.ReadByte();
length--;
controlBitsLeft = 8;
}
/* Decode a byte according to the current control byte bit */
if ((control_word & controlBitMask) != 0)
{
/* Straight copy, store into history ring */
data = reader.ReadByte();
length--;
writer.Write(data);
ring[ring_pos] = data;
ring_pos = (ring_pos + 1) % props.ringBufferSize;
decompLength--;
}
else
{
/* Reference to data in ring buffer */
switch (props.type)
{
case BemaniLZSS2Type.Firebeat:
cmd1 = reader.ReadByte();
cmd2 = reader.ReadByte();
length -= 2;
chunk_length = (cmd1 & 0x0F) + 3;
chunk_offset = (((int)cmd1 & 0xF0) << 4) + (int)cmd2;
chunk_offset = ring_pos - chunk_offset;
while (chunk_offset < 0)
{
chunk_offset += props.ringBufferSize;
}
break;
case BemaniLZSS2Type.GCZ:
cmd1 = reader.ReadByte();
cmd2 = reader.ReadByte();
length -= 2;
chunk_length = (cmd2 & 0x0F) + 3;
chunk_offset = (((int)cmd2 & 0xF0) << 4) | cmd1;
break;
default:
return;
}
for ( ; chunk_length > 0 && length > 0; chunk_length--)
{
/* Copy historical data to output AND current ring pos */
writer.Write(ring[chunk_offset]);
ring[ring_pos] = ring[chunk_offset];
/* Update counters */
chunk_offset = (chunk_offset + 1) % props.ringBufferSize;
ring_pos = (ring_pos + 1) % props.ringBufferSize;
decompLength--;
}
}
/* Get next control bit */
control_word >>= 1;
controlBitsLeft--;
}
}
}
static public void Compress(Stream source, Stream target, int length, BemaniLZSS2Properties props)
{
}
public static void Decompress(Stream source, Stream target, int length, int decompLength, BemaniLZSS2Properties props)
{
byte[] ring = new byte[props.ringBufferSize];
int ring_pos = props.ringBufferOffset;
int chunk_offset;
int chunk_length;
int control_word = 1;
int controlBitsLeft = 0;
int controlBitMask = 0x1;
byte cmd1;
byte cmd2;
byte data;
if (decompLength <= 0)
decompLength = int.MaxValue;
BinaryReaderEx sourceReader = new BinaryReaderEx(source);
BinaryWriterEx writer = new BinaryWriterEx(target);
using (MemoryStream mem = new MemoryStream(sourceReader.ReadBytes(length)))
{
BinaryReaderEx reader = new BinaryReaderEx(mem);
while (decompLength > 0 && length > 0)
{
if (controlBitsLeft == 0)
{
/* Read a control byte */
control_word = reader.ReadByte();
length--;
controlBitsLeft = 8;
}
/* Decode a byte according to the current control byte bit */
if ((control_word & controlBitMask) != 0)
{
/* Straight copy, store into history ring */
data = reader.ReadByte();
length--;
writer.Write(data);
ring[ring_pos] = data;
ring_pos = (ring_pos + 1) % props.ringBufferSize;
decompLength--;
}
else
{
/* Reference to data in ring buffer */
switch (props.type)
{
case BemaniLZSS2Type.Firebeat:
cmd1 = reader.ReadByte();
cmd2 = reader.ReadByte();
length -= 2;
chunk_length = (cmd1 & 0x0F) + 3;
chunk_offset = (((int)cmd1 & 0xF0) << 4) + (int)cmd2;
chunk_offset = ring_pos - chunk_offset;
while (chunk_offset < 0)
chunk_offset += props.ringBufferSize;
break;
case BemaniLZSS2Type.GCZ:
cmd1 = reader.ReadByte();
cmd2 = reader.ReadByte();
length -= 2;
chunk_length = (cmd2 & 0x0F) + 3;
chunk_offset = (((int)cmd2 & 0xF0) << 4) | cmd1;
break;
default:
return;
}
for ( ; chunk_length > 0 && length > 0 ; chunk_length--)
{
/* Copy historical data to output AND current ring pos */
writer.Write(ring[chunk_offset]);
ring[ring_pos] = ring[chunk_offset];
/* Update counters */
chunk_offset = (chunk_offset + 1) % props.ringBufferSize;
ring_pos = (ring_pos + 1) % props.ringBufferSize;
decompLength--;
}
}
/* Get next control bit */
control_word >>= 1;
controlBitsLeft--;
}
}
}
public static void Compress(Stream source, Stream target, int length, BemaniLZSS2Properties props)
{
}
public static void DecompressGCZ(Stream source, Stream target, int length, int decompLength)
{
BemaniLZSS2Properties props = new BemaniLZSS2Properties();
props.ringBufferOffset = 0xFFE;
props.ringBufferSize = 0x1000;
props.type = BemaniLZSS2Type.GCZ;
Decompress(source, target, length, decompLength, props);
}
