# Need Help with Understanding/Converting Game Formats



## acrash (Nov 30, 2021)

*This is for OG Xbox.*

I want to store my game collection in the most authentic way possible (matching Redump) but that takes a lot of storage. So, I did a little bit of research and now I have few questions (and few requests) that I hope someone could help me with.


It seems to me that there are three main formats for storing a retail OG Xbox disc: (1) Redump ISO   (2) XISO  (3) Extracted files/Game Folder
I did some testing with:
_Halo - Combat Evolved (USA) (Rev 2) *{crc="013986d0"}*
JSRF - Jet Set Radio Future (USA) *{crc="b2a882df"}*
Mortal Kombat - Deception (USA) *{crc="007bcbcc"}*_





*A
-----------------*
In the Xemu documentation it is mentioned that you can create an emulator-compatible .iso file by using either of the commands:

-with dd:
_dd.exe if={redump_game_name}.iso of={output_game_name}.iso skip=387 bs=1M_

-with extract-xiso:
_extract-xiso.exe -r {redump_game_name}.iso_

But these two methods produce different .iso files. The one created with dd.exe is much bigger.
A1- Are these two different forms of XISO or is the .iso file created with dd.exe just a trimming hack and not a proper XISO?
A2- Is what is trimmed with dd.exe the same for every retail disc (meaning we can just keep one copy to rebuild every disc with it)?
A3- What is the effect of using the two commands together?
A4- In this post JayFoxRox says that we can separate the video and game partitions and recombine them later. Also he says that the video partition is the same for most retail games. Is that true? What games have special video partition? How to separate the two partitions and recombine them to give the original Redump CRC?


If the video partition is the same for all/most games, that would mean that we can keep one copy of that partition to recreate the Redump ISO from any XISO file (saving a lot of space). The exception being the random padding that we need to find a way to recreate.



*B*
*-----------------*

Extracting the files from a Redump ISO with with extract-xiso
_extract-xiso.exe -x {redump_game_name}.iso_
then generating a .iso with them
_extract-xiso.exe -c {Folder_with_all_the_files}_



gives a .iso file with a different CRC32 to the .iso file that is created from
_extract-xiso.exe -r {redump_game_name}.iso_



I tried to use IsoBuster 4.8 (free) on a Redump ISO. It worked for listing the LBA for the files and for extracting the game files.



IsoBuster always showed 4 partitions for the Redump ISOs:
SEP13011042
SEP13011042072
VIDEO
XBOX

and two partitions for the XISO created with extract-xiso:
- _{it's just a dash}_
XBOX



The files didn't change (I extracted again and compared) but I noticed that the some LBA for the files is different. Maybe there is something else that is different as well?
B1- Is there a program that can create/edit ISO files based on LBA information (maybe like PS3 ISO Rebuilder with IRD files)?
B2- Does this mean that we need to create files like IRD files for the PS3 (Layout files?) to be able to recreate an XISO file from extracted files?
B3- Anyone knows a program that can do that for XISO files? For Redump ISO files? (similar to Redump2IRD)

*Note 1:* I tried IsoBuster 4.7 and didn't work for me. In their release notes for 4.8 they mention {better XISO support}.
*Note 2:* In my Github issue post, dzastsed provided a link to a compiled version of LedZeppelin68's DVD Shrinker [The Link]



*General Questions:*
1- Do you think we should start a database for the random blocks seeds using the tools in HERE? (even though we can't do it for all discs right now)
2- Can anyone provide the attachments from this thread?


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## acrash (Dec 3, 2021)

Xbox shrinker and the Redump files are in the attachments


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