lifegpc/GARbro-crskycode
1
0
Fork 0
mirror of https://github.com/crskycode/GARbro.git synced 2026-07-08 01:30:18 +08:00
Code Issues Packages Projects Releases Wiki Activity

Crc32 implementation moved to separate file.

Browse Source 
this implementation uses 'normal' polynomial representation unlike Crc32
defined in GameRes.
This commit is contained in:
morkt
2016-08-19 09:29:06 +04:00
parent 8808b54c88
commit 303a8551b0
4 changed files with 91 additions and 59 deletions
Download Patch File Download Diff File Expand all files Collapse all files

47
ArcFormats/TopCat/ArcTCD3.cs
View File

@@ -305,26 +305,6 @@ namespace GameRes.Formats.TopCat
data[i] = Binary.RotByteR (data[i], 1);
}
static Lazy<uint[]> OggCrcTable = new Lazy<uint[]> (InitOggCrcTable);
static uint[] InitOggCrcTable ()
{
var table = new uint[0x100];
for (uint i = 0; i < 0x100; ++i)
{
uint a = i << 24;
for (int j = 0; j < 8; ++j)
{
bool carry = 0 != (a & 0x80000000);
a <<= 1;
if (carry)
a ^= 0x04C11DB7;
}
table[i] = a;
}
return table;
}
Stream RestoreOggStream (ArcFile arc, Entry entry)
{
var data = arc.File.View.ReadBytes (entry.Offset, entry.Size);
@@ -332,32 +312,25 @@ namespace GameRes.Formats.TopCat
int src = 0;
while (remaining > 0x1B && Binary.AsciiEqual (data, src, "OggS"))
{
int d = data[src+0x1A];
int segment_count = data[src+0x1A];
data[src+0x16] = 0;
data[src+0x17] = 0;
data[src+0x18] = 0;
data[src+0x19] = 0;
int dst = src + 0x1B;
int count = d + 0x1B;
if (d != 0)
int page_size = segment_count + 0x1B;
if (segment_count != 0)
{
if (remaining < count)
if (remaining < page_size)
break;
for (int i = 0; i < d; ++i)
count += data[dst++];
int segment_table = src + 0x1B;
for (int i = 0; i < segment_count; ++i)
page_size += data[segment_table++];
}
remaining -= count;
remaining -= page_size;
if (remaining < 0)
break;
dst = src + 0x16;
uint crc = 0;
for (int i = 0; i < count; ++i)
{
uint x = (crc >> 24) ^ data[src++];
crc <<= 8;
crc ^= OggCrcTable.Value[x];
}
LittleEndian.Pack (crc, data, dst);
uint crc = Crc32Normal.UpdateCrc (0, data, src, page_size);
LittleEndian.Pack (crc, data, src+0x16);
}
return new MemoryStream (data);
}