There have been instances where I have wanted to go back to a DVD and make some changes to the way I edited the actual program. Is there a way to do this? I'm not talking about editing the DVD menu, but editing the actual program itself (such as removing a shot, changing a shot sequence, etc.)?

It is (quite) hard to do, so I would not advice it. Normally you'd
work with the original footage and load the original DVD project
and create a new DVD.

However it is possible (but you will STILL need to re-create the
entire DVD, so it far FAR better to work with original footage if you
can!!) to extract the video/audio from a DVD and start again.

The information is in the VOB files. Which ones depends on the
menus, the amount of footage etc. Any section that is larger than
1 GB is split over multiple VOB files and each media section
(including menus) have their own VOB sequence.

These are just MPEG-2 transport/program streams. So you might
want to copy these and rename them to .MPG and see if a program
will accept these.

If not you might need to get a DVD ripper and/or demuxer to
get the individual audio and video streams out of this mixed
MPEG-2 file and work with those.

Rob,
Thanks for the info. I had some success in doing this. By renaming them with m2v, I could get them to play in quicktime but there is no audio. Any suggestions?

I think that "m2v" files are MPEG-2 video only (and "m2a" are MPEG-2 audio files). Did "mpg" work? This is a muxed video/audio file, so Quicktime might see both streams then. Otherwise, as Rob mentioned, you'll need some kind of program that can extract the MPEG-2 data from the VOB file and save it in a real "mpg" file.

The problem with audio is that it is NOT in an MPEG encoding on
a DVD. It usually is in AC3 (Dolby Digital) or PCM (uncompressed).
So most programs don't expect this or do not know how to handle
it (in case of AC3 it is not handled due to copyright issues).

So you will need to extract the audio stream with a demuxer like
bbTools (see http://www.doom9.org/ and then downloads)
for example.

If it is AC3 you will need to decode this to PCM/WAV first which
you can do with a program like BeSweet (do a google search).

Good point, Rob. 'Hadn't thought of that.

there is a program that a friend gave me.

It just says dvd yade. Not sure if that's much help.

But i have pulled footage off dvd's using my canopus advc 100 interface.

But I'm not sure if you want to spend $200 bucks. I use it to see my footage on a regular tv screen until I get a broadcast monitor. But I'll still keep the canopus it gives you a good idea of the what the footage looks like on a real tv.

These aren't really for dvd footage editing but MyDVDEdit and TFDVDEdit are two mac apps that let you do lots of re-authoring.

Quick google search will throw both sites up,

Jake

Use DVDdecrypter to extract and demux the files from the DVD. You will get an MPEG-2 video file and a AC3 audio file. Then use Canopus Procoder to convert the MPEG-2 to AVI.

Best regards.
Arnaldo