Unp4cker is a PowerShell script, and requires certain arguments to operate. But don’t worry if you’re not used to command-line: it’s simple!
First, download Unp4cker and extract the .zip file contents anywhere on your PC. Temp files will be located next to the script, so make sure you have write permissions on a drive with at least a few GB free.
If you don’t use it often, you may be surprised to find that Windows 10 has a variety of convenient ways to open PowerShell right where you want it! Any of the following methods will do just fine:
2.5. Enable PowerShell script execution
By default, PowerShell disallows running any custom scripts to protect against malicious scripts. If you’ve never used PowerShell scripts before, you’ll need to enable them in one of two ways:
3. Unpack a file with Unp4cker
With PowerShell open and the current directory set to the unp4cker folder, you’re ready to start issuing commands!
To unpack a file with Unp4acker, simply type the script file followed by the path to a movie archive in your Persona 4 Golden Steam library:
Note: The “.\” tells PowerShell to look for Unp4cker in the current directory. If you start typing “unp4cker” and press Tab, it will autocomplete this part for you.
Movie files will be extracted to a folder next to Unp4cker with the same name as the archive.
4. Repack a file with Unp4cker
Once you’ve made any modifications to the extracted files, you can repack them again into a new archive for use with P4G.
Warning: This feature is experimental and may not work as expected. Always back up original archives first!
Repacking an archive requires all files from the original archive to be present in the extracted folder. It is not currently possible to replace an individual file.
In other words, the number of files in the folder to repack must equal the number of files in the original archive.
To pack a file with Unp4cker, you will need to input two paths: 1) the path of the original archive, and 2) the path of the folder containing files to pack. The second path must be preceded by the “–pack” command to indicate the path is a source folder.
.\unp4cker.ps1 S:\SteamLibrary\SteamApps\common\Day\movie00002.pac –pack C:\unp4cker\extracted\movie00002
This will create a new version of the archive in an “out” folder next to Unp4cker. Copy it into your P4G Steam library and replace the original (make sure you have a backup first!), then run the game to see the results!