Kostya's Boring Codec World

What should follow a political rant that nobody would read? A release of a tool that nobody would use of course!

I’m indifferent to announce the release of na_game_tool version 0.6.0, now with AVI support. Beside being able to write output to AVI it can now also de-obfuscate some AVI files that employ some simple scheme (like XORing with a 32-bit counter). And in addition to that it can also reconstruct Smacker and audio files from AVIs (or IAVFs) used in Black Dahlia and Ripper games.

The rest of the newly-added formats are mostly those I found at discmaster.textfiles.com by searching for unknown files over several megabytes large (and filtering out corrupted samples, segments from the multi-part archives, etc). Despite discmaster not being updated anymore (you know whom to thank for the storage shortage), I’ve found enough to have another release in the future.

Meanwhile here are some short notes about some formats:

• Elige Tu Muerte is extremely short but very FMV game: it’s a dozen of .mov files with animations plus 20kB .exe engine. You just click on one of four exits and 3D-rendered figure walks there to its demise (which should be obvious from the game title). The coding format is slightly more complex than normal RLE but still nothing to write a full post about;
• Lords of the Realm VAS format is the one I halfway reverse-engineered from the files themselves and then found corresponding RLE decompression code in the binary specification to fill in the missing details. The main problem there is that it’s an overlay executable so some parts are not loaded by default and there are no references to the decompression functions;
• Tie Break Tennis 98 intro file was reverse engineered from its contents because it was less effort than to manually load LE segment of the binary specification into Ghidra. After all it has just four opcodes (fill block, raw block, skip block, and palette) so guessing the whole structure was easy;
• Gunmetal SBV gets another mention here by being the only wavelet video codec I’ve encountered in a game so far;
• this time I had three formats that should’ve been video files in theory but turned out to be an archive of video and audio tracks in stand-alone formats, optionally with some commands telling how to play them. Those formats are AVI, SMS and Knowledge Adventure movie v3.

na_game_tool is available at the usual place in the usual format.

Now I can move to work on a different tool which would tackle a format that’s very widespread and extremely exotic at the same time.

This entry was posted on Saturday, September 5th, 2026 at 4:44 am and is filed under NihAV. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.