In reply to Jack B:
I found that VLC would play the .ts streams pulled from the Humax last night, and did a pretty good job on the PC; good picture quality (on a 14" monitor, mind...), and good lipsync audio.
I've just spotted that it also claims to do conversion as you suggest, but I tried it and it came back with an empty output file immediately; I'm sure I must have done something wrong. I could probably do with getting the latest version, as I'm sure the one installed on the PC is ancient; I can't remember installing it...
Currently trying Oxelon media converter, but there's a vast array of output file formats... Currently converting to AVI container, MPEG4 video, MP3 audio, with HDReady output resolution. We'll see how that goes... It's using the ffmpeg library fro the conversion.
It's going to take a long time to convert everything, so I'd like to make a good choice of container, video & audio formats. Some experimentation is in order...
The plan was to convert on my PC, but I guess I could try one of the little quadcore android media boxes I have (and would be used for playback).
Thanks for the suggestions. Keep them coming...