Thank you for that information.
Now, another question, please: are they planning on playing the disc that you deliver in a DVD player, attached to, or built into their TV?
The reason that I ask is that few DVD player, whether set-top, or integral, can play DVD-Data discs. Now, some can play what is a hybrid, referred to as VCD (Video-CD), but not all. However, with one caveat [later], they are all certified to play DVD-Video discs. Those are the ones that I referred to as being "authored."
I hope to help you get a final product that will satisfy your clients, and play easily on their equipment. It can become frustrating to all parties, if something, that will not work, gets handed off - I have been there, done that. It can also be frustrating to a producer, when they think they are delivering exactly what has been requested, but is not working, as anticipated.
If their player(s), CAN handle an AVI file on a DVD-Data, they with the conversion, you should be good to go. I just fear, as most DVD players cannot play DVD-Data discs, that there will be disappointment. Same for a VCD.
If possible, can you get the make/model of their DVD player(s). It should be easy to then find the capabilities, and check those out.
Also, and depending on the equipment, there could be other, non-disc delivery schemes. For instance, I have several TV's, and two HD DVR/cable boxes, that can accept a USB thumbdrive, with certain media files on them. In those cases, I just plug in a thumbdrive, navigate to it via the TV/DVR remote, and play (certain formats, like you mentioned earlier). If their equipment allows for that, unless their DVD player allows for the play of discs that are not DVD-Video, that might be the better delivery scheme.
Again, I know I am throwing a lot of info at you, but perhaps with a few questions answered, you can give them something that will be perfect.
Good luck,
Hunt
PS - now the caveat: All DVD players, with the "DVD" logo, are certified to play all replicated (commercial) DVD's, both SL (Single-layer DVD-5) and DL (Double-layer DVD-9). However, and depending on the player, plus the qualtiy of the blank media, and the quality of the burn, they are not certified to play ANY burned disc, but most will.