If you’ve just spent an age downloading a huge MKV file, then eventually discovering that it won’t play properly is always going to be, well, a little frustrating. To put it politely.

It’s best to resist your immediate urge to shout a lot and break things, though, because there may still be hope. Grab a copy of the free Meteorite and it’s just possible that the program will be able to restore your movie to its full working order.

This was just the kind of tool we’d expect to come with a bunch of annoying browser toolbars, but fortunately this has none at all. The SourceForge download page delivers only simple executables for Windows, Linux and OS X, no unwanted extras to worry about.

And we do mean “simple executables”. Our Windows download unzipped to a couple of files – Meteorite.exe, barely 1MB in size, and a copy of the GPL – so there’s no installation involved.

This isn't some desktop gadget accessory - it's the entire Meteorite interface. No, really.

And on launch, Meteorite displays a tiny window where you can drag and drop your broken video, and that’s it. There’s no other significant interface, no options dialog, no configuration or setup of any kind. Just drag and drop “filename.mkv” onto Meteorite, and if possible it’ll rebuild a new “meteorite.filename.mkv” in the same folder, hopefully with any playback problems resolved.

Does it work? A version number of 0.11 suggests it’s probably wise to keep your expectations low, and sure enough the program seems quite limited. We tried it with 10 sample videos which we’d intentionally corrupted in various ways, and it was fully successful in two cases, partially in one, but could do nothing at all with the other seven.

The basic interface doesn’t deliver the help you might expect, either. If you drag and drop in a file which is so corrupted that it’s not recognised as an MKV, for instance, then you’d expect to be told that, right? But no. Meteorite simply ignores it, giving you no feedback at all.

Of course repairing videos can be a horribly complicated process, though, so Meteorite deserves considerable praise for achieving anything at all. Especially in such a straightforward format, where you’re able to try it without worrying about being tricked into installing some toolbar or other. And so if you ever download MKV files then we’d recommend you keep a copy to hand, just to try and help out with any future playback problems.