Play It Again

What follows is some utterly fascinating research regarding a non-Xanmovie method of playing Wing Commander III and IV videos from K Moon...

Reading up about xanmovie, and having recently (as of a few months ago) acquired a copy of Wing Commander IV, I was intrigued by claims that, though a normal AVI file, WC3/4 movies could only be played by a special file.

Installing the Win95 patch for WC4, I noticed the addition of the xanlib.dll file. Looking at it with a text editor exposed some interesting-looking lines at the end. I reasoned that it was possible that Xan was implemented as a standard Windows AVI codec, which means it wouldn't be terribly hard to add support for it to standard Windows Media Player.

At first, I thought I'd need to do some heavy hacking with the files. I began by disassembling the code, exporting symbol tables, and other programming activities, researching the interface to xanlib.dll. Before actually writing any code, though, I decided to try something stupid: just add xanlib.dll as a video codec.

Well, it worked.

My initial experiment, hacking the registry under Windows 2000, was a remarkable success. However, trying to apply it to Win98SE, things didn't work as I expected. After a few minutes of reflection, I hit upon the solution.

You need to add the following line under the [drivers32] section in the system.ini (in C:\Windows). It's simple text file that I'm sure many frustrated Windows users were familiar with, before the advent of Win95 and friends.

vidc.XXAN=xanlib.dll

You also need to copy xanlib.dll into the C:\Windows\System directory, so Windows can find it.

Now there's a XXAN decoder available for decoding movies with XXAN compression (the Wing Commander 3/4 movies!), and normal Windows Media Player (I used version 7) can play it.

I tried this out with the hidden Wilford scene available from the CIC (hidden3.zip) and it worked beautifully. The only problem? No sound. I believe the audio is just encoded as regular PCM, so it's a real mystery why it can't read it. I'm going to do some research into the AVI file format, and maybe turn up an answer.

Until then, it's a start. Also, since XXAN is used as a standard decompressor, it might open the possibility of reconverting it into another format using standard video editting software.