convert audio into blank video?

[Laconic]

I've created a subtitles file (.srt) to go with an .mp3 audio podcast. And it plays great on VLC (although having to have a visualisation playing to use subtitles is a bit weird). But being able to subtitle audio seems a rare feature, and so to make my subtitles accessible to people with more basic players, I would like to create a blank video from the audio. I might then proceed to burn subtitles into that. So my question is: can VLC convert audio to a blank video? It can certainly convert audio formats to video formats, but I suspect it is just leaving out the video stream, because when I play that video in other players they reject it.
Thanks,
Lac.

[Jean-Baptiste Kempf]

I don't think VLC can do that.

[Laconic]

Using Microsoft Movie Maker I have managed to combine my audio with a blank title to create a blank WMV file.
And VLC seems to be able to convert that to other formats - but there's a lot of choice!
I'm now trying to research good formats for containing the subtitles (as text, to keep the filesize low). Ideally I'd like a format that Windows Media Player would play complete with subtitles.