rpgmvp-view

A shell extension to directly preview .rpgmvp files in Windows File Explorer. Also provides a convenient context menu option to convert it to a PNG file.

Warning

The assets previewed belongs to their respective game developers, please do not steal and reuse stuff! This tool is only intended for thumbnail previews and does not modify anything permanently. If you love a game's art, consider supporting the developer!

Installation

1. Download the .dll from release, and keep it somewhere where you won't delete it.
2. Open "Command Prompt" as Administrator.
3. Run this command: regsvr32 <path to dll>, where path to dll is the location the downloaded dll is in.
4. You should see a message box saying it succeeded.

In order to uninstall

Run this command: regsvr32 /u <path to dll>, where path to dll is the location the downloaded dll is in.

FAQ

• If you still get blank white thumbnails, try clearing your thumbnail cache files, located in this folder: %localappdata%\Microsoft\Windows\Explorer, all the thumbcache_ files. You may need to close explorer.exe before deleting them. OR try using Disk Cleanup to clear Thumbnails

How it works

RPGMVP files are not really encrypted, they are just PNG files obfuscated. It does this by appending the RPGMV header(16 bytes) before the PNG file bytes, and XORing the next 16 bytes with the encryption key.

Conveniently the first 16 bytes of a PNG file are fixed across all PNG files, composed of

• the PNG Header (8 bytes),
• the IHDR Header,
  • composed of IHDR length (4 bytes) whose value is 13,
  • text "IHDR" (4 bytes).

So if we remove the first 16 bytes (RPGMV header) and replace the next 16 bytes with the known values, we get a proper PNG image.

This tool adds a context menu item to conveniently convert a .rpgmvp to a .png file.