LeeThorogood said:
Jonno thanks for the info ;) when you say a simple authoring program would muxman do the trick? *sigh* this project just seems to get more and more complicated all the time!
Yes and no ;)
Yes because Muxman would certainly allow you to add your own list of celltimes, but no because you need to place those cell breaks in the context of your own edit/encode, requiring a visual timeline interface.
Ideally you'd use something like Adobe Encore to put this part together - it's got a very flexible timeline and (if you don't mind using its inbuilt MPEG encoder) can even encode around the chapter points you've placed on your AVI, so those can be positioned on precise frames (and the encoder will just force I-frames on those).
Simpler software will probably just let you mark chapters on existing I-frames in the MPEG stream - obviously you won't know what these are until you try navigating around the timeline (you'll only be able to 'park' the cursor on an I-frame) - and then build the video and audio streams into DVD-legal specs.
Perhaps have a browse through these programs for one that will fit the bill/budget (unless someone else can weight in and supplement my own limited knowledge!)
http://www.videohelp.com/tools/sections/authoring-dvd
Of course I could simply offer to do this part for you, if there's an easy way for us to exchange the materials. Sounds like you might need to sort out the issues with your video streams first, but let me know :)