Bussun/BMGEditor
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all the code I find seems to be based on thakis code

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too bad I just can't figure it out by myself, I'd rewrite it if I could.
I'm pretty sure it's just one little stupid thing that makes it decode it incorrectly for sm3das
This commit is contained in:
Denis
2022-01-28 22:58:37 +01:00
parent 14ea70ad7a
commit b4f2ce301d
1 changed files with 54 additions and 21 deletions
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75
BMGEditor/FS/Yaz0Stream.cs
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@@ -33,36 +33,69 @@ namespace BMGEditor
return;
Int32 decompSize = (data[4] << 24 | data[5] << 16 | data[6] << 8 | data[7]);
byte[] output = new byte[decompSize];
int Offs = 16;
int dstoffs = 0;
while (true)
uint sourcePos = 16; //start at 0x10
uint writePos = 0; //destination to write data to
byte[] decodedData = new byte[decompSize + 1];
byte groupHead = 0;
byte lastGroupHead = 0;
uint validBitCount = 0;
while (writePos < decompSize)
{
byte header = data[Offs++];
for (int i = 0; i < 8; i++)
//System.Windows.Forms.MessageBox.Show(groupHead.ToString("X") + "|" + validBitCount);
if (validBitCount == 0) //new group header
{
if ((header & 0x80) != 0) output[dstoffs++] = data[Offs++];
groupHead = data[sourcePos];
lastGroupHead = groupHead;
++sourcePos;
validBitCount = 8; //reset count
}
if ((groupHead & 0x80) != 0) //straight copy as long as groupheader maintains left most bit as 1 (1000 0000)
{
decodedData[writePos] = data[sourcePos];
writePos++;
sourcePos++;
}
else
{
byte b1 = data[sourcePos]; //byte 1
byte b2 = data[sourcePos + 1]; //byte 2
sourcePos += 2; //move past those two bytes
uint dist = (uint)((b1 & 0xF) << 8) | b2; //distance
if (Tests.isBE)
dist = (UInt32)((dist >> 24) | ((dist & 0xFF0000) >> 8) | ((dist & 0xFF00) << 8) | (dist << 24));
uint copySource = writePos - (dist + 1); //copy
uint numBytes = (uint)b1 >> 4; //how many bytes to copy
//if (sourcePos-2 > 0x13C0) //debug decode
//System.Windows.Forms.MessageBox.Show("lastGroupHead: 0x" + lastGroupHead.ToString("X") + "\n" + "b1: 0x" + b1.ToString("X") + "\n" + "b2: 0x" + b2.ToString("X") + "\n" + "sourcePos: 0x" + sourcePos.ToString("X") + "\n" + "dist: " + dist + "\n" + "copySource: 0x" + copySource.ToString("X") + "\n" + "writePos: 0x" + writePos.ToString("X") + "\n" + "numBytes: " + numBytes);
if (numBytes == 0) //If the first 4 bits of the first byte is 0...
{
numBytes = data[sourcePos] + (uint)0x12;
sourcePos++;
}
else
{
byte b = data[Offs++];
int offs = ((b & 0xF) << 8 | data[Offs++]) + 1;
int length = (b >> 4) + 2;
if (length == 2) length = data[Offs++] + 0x12;
for (int j = 0; j < length; j++)
{
output[dstoffs] = output[dstoffs - offs];
dstoffs++;
}
numBytes += 2;
}
if (dstoffs >= decompSize)
for (int i = 0; i < numBytes; ++i)
{
Array.Resize(ref data, decompSize);
output.CopyTo(data, 0);
return;
decodedData[writePos] = decodedData[copySource];
copySource++;
writePos++;
}
header <<= 1;
}
groupHead <<= 1; //left shift!!!
validBitCount -= 1; //group header validation count of the binary position
}
Array.Resize(ref data, decompSize + 1);
decodedData.CopyTo(data, 0);
FileStream test = File.OpenWrite("./test.bin");
test.Write(data);
return;
}
}
}