How can you edit a previously burned DVD from an older iMovie app?

Question

I converted VHS home movies to DVD years ago on the origonal iMovie app.  How can I edit those DVD's now?  Do I need a third party app to convert the DVD files for use in the new iMovie?

Answer 1

Yes, you need to 'reverse engineer' the highly compressed mpeg2 format of the DVDs.
You need to convert the VOB files in the TS-Folder of the DVD back to DV which iMovie is designed to handle. For that you need mpegStreamclip:
http://www.squared5.com/svideo/mpeg-streamclip-mac.html
which is free, but you must also have the  Apple mpeg2 plugin :
http://www.apple.com/quicktime/mpeg2/
(unless you are running Lion in which case see below))
which is a mere $20.
Another possibility is to use DVDxDV:
http://www.dvdxdv.com/NewFolderLookSite/Products/DVDxDV.overview.htm
which costs $25.
For the benefit of others who may read this thread:
Obviously the foregoing only applies to DVDs you have made yourself, or other home-made DVDs that have been given to you. It will NOT work on copy-protected commercial DVDs, which in any case would be illegal.
If you are running Lion:
From the MPEG Streamclip homepage
The installer of the MPEG-2 Playback Component may refuse to install the component in Lion. Apple states the component is unnecessary in Lion, however MPEG Streamclip still needs it.
To install the component in Lion, please download MPEG Streamclip 1.9.3b7 beta above; inside the disk image you will find the Utility MPEG2 Component Lion: use it to install the MPEG-2 Playback Component in Lion. The original installer's disk image (QuickTimeMPEG2.dmg) is required.
The current versions of MPEG Streamclip cannot take advantage of the built-in MPEG-2 functionality of Lion. For MPEG-2 files you still need to install the QuickTime MPEG-2 Playback Component, which is not preinstalled in Lion. You don't have to install QuickTime 7.