There's no workaround, MP4 is a patent-encumbered format and since node-webkit is based on open-source code which hasn't paid any of the royalty fees, it can't support the patented formats. You need to encode your video to Theora or WebM. You need to do that anyway, for any platform, since for the same reason, not all web browsers or OSs support MP4.
Ahh, alright, good to know. Thanks!
There are obviously commercial programs that will convert to ogm/webm, but you could also try the free video player VLC from Videolan. It includes the facility to convert between many formats. Might worth a try.
Ive been fiddling with VLC; I've got the quality issue sorted, but for whatever reason construct refuses to play the file. Is there maybe a specific bitrate, or codec I should be using? Right now I'm using the VP8 codec, and 2000 kb/s bitrate.
Thanks for the replies!
Edit:
Nevermind, turns out I'm just a bit dense. I just now realized that ive been testing in IE this whole time, which I guess doesnt support webm