IDVD won't give an option for higher capacity DL discs

Question

Hello,
Using iDVD version 7.1.2 (1158)
In the 'Project Info' window, under 'DVD Type:' the only options given are Single Layer 4.2GB or Double-Layer 7.7GB.
According to the info, my project is 150 min, 8.21 GB.
I'd like to burn a DVD using Memorex DVD+RDL media which has a stated capacity of 8.5GB or 240Min (from the label).  There is no option for this.
Is there a reason why Apple gives 2 such strange sized options for SL and DL options?  Is iDVD reserving room on the disc for other stuff?
Thank you for your help!

Answer 1

Whether you can use DL disks is not governed by iDVD but by your superdrive. Check in 'About this Mac' if yours supports dual layer media.
Memorex is not recommended. Verbatim or Taiyo Yuden are.
150 minutes should fit comfortably on a DL disk, as the project will of course be compressed to the standard DVD format of mpeg2:
iDVD encoding settings:
http://support.apple.com/kb/HT1502?viewlocale=en_US
Short version:
Best Performance is for videos of up to 60 minutes
Best Quality is for videos of up to 120 minutes
Professional Quality is also for up to 120 minutes but even higher quality (and takes much longer)
That was for single-layer DVDs. Double these numbers for dual-layer DVDs.
Professional Quality: The Professional Quality option uses advanced two-pass technology to encode your video (The first pass determines which parts of the movie can be given greater compresson without quality loss and which parts can’t.  The second pass then encodes those different parts accordingly) , resulting in the best quality of video possible on your burned DVD. You can select this option regardless of your project’s duration (up to 2 hours of video for a single-layer disc and 4 hours for a double-layer disc). Because Professional Quality encoding is time-consuming (requiring about twice as much time to encode a project as the High Quality option, for example) choose it only if you are not concerned about the time taken.
In both cases the maximum length includes titles, transitions and effects etc. Allow about 15 minutes for these.
You can use the amount of video in your project as a rough determination of which method to choose. If your project has an hour or less of video (for a single-layer disc), choose Best Performance. If it has between 1 and 2 hours of video (for a single-layer disc), choose High Quality. If you want the best possible encoding quality for projects that are up to 2 hours (for a single-layer disc), choose Professional Quality. This option takes about twice as long as the High Quality option, so select it only if time is not an issue for you.
Use the Capacity meter in the Project Info window (choose Project > Project Info) to determine how many minutes of video your project contains.
NOTE: With the Best Performance setting, you can turn background encoding off by choosing Advanced > “Encode in Background.” The checkmark is removed to show it’s no longer selected. Turning off background encoding can help performance if your system seems sluggish.
And whilst checking these settings in iDVD Preferences, make sure that the settings for NTSC/PAL and DV/DV Widescreen are also what you want.
http://support.apple.com/kb/HT1502?viewlocale=en_US