For six years I have created iMovie projects and sent them to iDVD (Share > iDVD) where I create a theme page and burn them to a DVD. Outside of a few minor glitches, I have created 40 110 minute movies, sent them to iDVD, burned them and then saved the disk image. I have a fair degree of experience at this.
Now, all of a sudden, my latest 7 iMovie projects (typically 90 - 110 minutes each) will not burn in iDVD due to the project exceeding the disk's capacity. The messages I get are "Multiplexer Error" and "Project Duration" (your project exceeds the max content duration).
Before I burn the DVD I make sure to adjust the Encoding setting within iDVD Project Info from Best Performance to either High Quality or Professional Quality - when I do this the capacity bar resets from exceeding capacity to about 3.5 GB at a time of about 100 minutes, which is within both the project capacity and my DVD disk capacity (Verbatim, 4.7GB, 16X, 120 min). The burning process take 2 1/2 - 3 hours, and only at the very end of this process do I get the message about Multiplexer Error or Project Duration. When I open the Project Info after the failed burning initiative, the capacity bar has grown and shows in red text, 6.7 GB and 120 min.
Somewhere in the iDVD burning process my iMovie file (typically 3.5 GB and 100 min in my previous 40 movies) is inexplicably expanding to about 7 GB, which is beyond the DVD disk's capacity, which blocks the burning process. I have spent hours in the Apple Community Support Forums reading about Multiplexer Error and hypothetical causes and fixes. None of these seem to apply to my simple projects. I spent the past 8 days adjusting these 7 problem iMovie projects and still they won't burn.
I have created MPEG4 files (.m4v) for these 7 "problematic" iMovie projects and they average about 2.7 GB and 100 min, which are about the same MPEG4 size as the previous movie projects I sent to iDVD for burning. So there is consistency between my successful and unsuccessful iMovie project size (about 100 min) and MPEG4 2.7 GB sizes. The issue is my recent iMovie projects are expanding their code volume within iDVD. Why?
Is it possible there is a problem within iDVD - did I accidently change the settings within iDVD, or is there a permanent problem within my iDVD?
Or is the technical diagnosis and fix of the problem so complicated that I'm better off buying a new DVD burning software? Do you think new burning software will solve my issue? Any other thoughts / suggestions?
iMac OS X 10.7.5
iMovie '11 9.0.8