ROM Hack error while opening ARC files of MT Framework

[kongcaodm]

I tried to open the .arc files (extracted from Ace Attorney: Dual Destinies) with Karameru and freearc, but failed.

The first 8 bytes of arc files are: (for example)
00000000.arc - 41 52 43 43 07 00 15 00 - ARCC....
00000018.arc - 41 52 43 43 07 00 15 00 - ARCC....
00000875.arc - 41 52 43 43 07 00 15 00 - ARCC....

I'm wondering if they are encrypted

p.s. please rename .rar to .arc which is the original one

Any help appreciated. Thanks in advance.

 

[kongcaodm]

I used EFE(EveryFileExplorer) to open 00000000.arc, 00000018.arc and 00000875.arc but nothing happened.

Then, I followed post#390 in the thread
( /threads/project-the-great-ace-attorney-dai-gyakuten-saiban-fan-translation.427572/page-20#post-6685429 )

I used arcUnpack.py with python 2.7 to unpack 0, 18 and 875.arc but all failed.
Most lines read 'incomplete or truncated stream' and the last line read 'incorrect header check'

The error of 00000000.arc with arcUnpack.py showed like this:

WY忝?.k-T;?%襗9:?IUx~@骞????1V failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%襗9:?IUxD?鶚>饊鳑?[l0 failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%襗9:?IUx斏D+] failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%襗9:?IUxH诲Y禋?溴爹嘎M failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%襗9:?IUx 断＾8#.{惰? failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%襢┧?貛6P4谖xZ揨 failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%?暀焐痰?．???B鮲i? failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%?8婯    焹募?塮A failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%?8婯    焹      i?@s failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%?8婯    焹@ZㄅF塿豍?潪3 failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%?8婯    焹羥&┊@,昚?? failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%?8婯    焹5螕KmN肟 failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%?8婯    焹蕦On?Z?(腍?畍 failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%?隶鈴A墋刮簰???彤齩?failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%尧{揳^揚霹倨/% failed to decompress, Error -5 while decompressing data: incomplete or truncated stream

WY忝?.k-T;?%?w拑Mq"??(?暃仹?乥 failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%覔顅X?r?忀€ failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%曳倣}頯3曇o???懻璁q!旞 failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T;?%??J卟{兔鸠駽梋 failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T€瀁?P黹?j杮qE???o?failed to decompress, Error -5 while decompressing data: incomplete or truncated stream
WY忝?.k-T€瀁?P黹?j杮qE???o?failed to decompress, Error -3 while decompressing data: incorrect header check

It made me more confused.

 

[kongcaodm]

.ARCC is pretty rare for me though

 

[kongcaodm]

Could anybody give me some hints about opening this kinda .arc files, or some advice about which other forums I could ask for help in? Thanks in advance.

 

[onepiecefreak]

This issue was first reported for Kuriimu here: https://github.com/IcySon55/Kuriimu/issues/623
It is solved in Kuriimu2's Release 1.2.0 and up.

The given files are ARCC. Those are encrypted versions of Capcom MT ARC's and after decryption they can be read as any MT ARC found on other platforms.
Capcom uses a slightly custom version of Blowfish, where the two 32 bit values of a 64bit block are read in little endian, instead of big endian. Refer to the implementation of the format and a Stream class for this here:
https://github.com/FanTranslatorsIn...s/Capcom/plugin_mt_framework/Archives/Arcc.cs
https://github.com/FanTranslatorsIn...in_mt_framework/Archives/MtArcSupport.cs#L173

With those information and a fix to the original issue, this thread can be seen as closed.

Edit: The link to Arcc.cs does contain the actual keys to de-/encrypt ARCC's if you have the correct Blowfish implementation as well. If this somehow goes against forum rules, please tell me or remove the link to Arcc.cs! Thank you.

 

[Splodge5]

Sorry to hijack the thread a little but I'm having a similar problem even with Kuriimu2 1.2.1. I'm trying to open .arc files from the great ace attoney chronicles but I get the error Specified argument was out of the range of valid values (Parameter 'length').
Trying with Karameru from Kuriimu 1 gives a more detailed but very similar error:

System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
Parameter name: length
    at Kontract.IO.SubStream..ctor(Stream baseStream, Int64 offset, Int64 length)
    at
archive_mt.MTARC.<>c__DisplayClass10_0.<ctor>b__1(FileMetadata metadata)
    at
System.Linq.Enumerable.WhereSelectListIterator`2.MoveNext()
    at System.Collections.Generic.List`1.InsertRange(Int32 index, IEnumerable`1 collection)
    at archive_mt.MTARC..ctor(Stream input)
    at archive_mt.MTArcManager.Load(String filename)
    at Karameru.Manager.OpenFile(String filename)

.
I'm new to these tools (and not great at C#) so I've no idea if I'm doing something wrong, if its a general bug, or if its a file-specific issue.
Any input is appreciated

 

[onepiecefreak]

Sorry to hijack the thread a little but I'm having a similar problem even with Kuriimu2 1.2.1. I'm trying to open .arc files from the great ace attoney chronicles but I get the error Specified argument was out of the range of valid values (Parameter 'length').
Trying with Karameru from Kuriimu 1 gives a more detailed but very similar error:

System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
Parameter name: length
    at Kontract.IO.SubStream..ctor(Stream baseStream, Int64 offset, Int64 length)
    at
archive_mt.MTARC.<>c__DisplayClass10_0.<ctor>b__1(FileMetadata metadata)
    at
System.Linq.Enumerable.WhereSelectListIterator`2.MoveNext()
    at System.Collections.Generic.List`1.InsertRange(Int32 index, IEnumerable`1 collection)
    at archive_mt.MTARC..ctor(Stream input)
    at archive_mt.MTArcManager.Load(String filename)
    at Karameru.Manager.OpenFile(String filename)

.
I'm new to these tools (and not great at C#) so I've no idea if I'm doing something wrong, if its a general bug, or if its a file-specific issue.
Any input is appreciated

Please create an issue for that on our github here: https://github.com/FanTranslatorsInternational/Kuriimu2/issues
That helps us keep track of such problems, so we can solve them later.