G'Day Tom. You are an Aussie like myself by the look of it? Welcome to the forum.
I assume you are referring to my post here:
http://yabb.jriver.com/interact/index.php?topic=105793.0I'm just a user like you, and wrote that because I had been looking for an easy way to convert JTV files to TS (or some other useful format) for some time. So, no guarantees it is going to work, and in fact the DirectShow filters I used do have limitations.
So, let's look at what is going wrong. First, as Jim noted and you observed, obviously your malware software wasn't helping. Killing the software is one way to prevent that. Excluding all directories that just contain media files from analysis is another way. You might also get it to stop loading up the CPU by doing a full scan of the directories where the media files are before trying any conversion, although if you have "on access" analysis turned on, then it is probably still going to be an issue.
So first things first, what is the source of your file(s) that won't convert?
You say they are analogue files, but all TV in Australia is now digital, and if the files are in JTV format, then they must have been recorded from TV broadcasts, and hence be digital.
So could you download the MediaInfo program from
https://sourceforge.net/projects/mediainfo/, install it, and open one of the problem files with it, display the results in Text format, and post them here.
Thanks.