As with all media, there is some overhead associated with disk storage due to formatting and directory structure. The small 170MB difference between your "4.2" GB project size and the "4.37" GB disk capacity probably reflects that overhead. There is no way around it other than data compression. And it's generally advisable not to try to fill the disk to capacity anyway.
If you have not tried it yet, change iDVD's encoding setting to High Quality or Professional Quality - using one of these options may enable iDVD to eke out that little bit of extra compression required to fit your project on the disk because iDVD will calculate the needed compression at the time you burn your DVD, based on the capacity of the disk and your project size.
That said, it would help if you identify the specific media you are using as well as the version of iDVD you are using.
Oh...sorry i typed wrong there. So, the real deal is that the DVD i got has 4,7GB of space and the project size is 4,4GB, so there should be 300MB of extra space.
But the iDVD doesn't recognize the real free space that my DVD has, but assumes that SL DVD is only 4,2GB and so claims that the data won't fit.
Please confirm what encoding setting you are using in iDVD. (Project > Project Info > Encoding.)
If it is Best Performance, change it to High Quality or Professional Quality.
You cannot literally fill the disk with your own media (video, stills, menus). DVDs have a structure that requires space in addition to your own material (that's the overhead I mentioned above). The 4.2GB that you see reported in iDVD's "Media Type" setting is *NOT* an interpretation of the blank media capacity. It is the maximum project size that can be written to the type of media. For single-layer DVD media, that limit is 4.2GB. You said your project is 4.4GB. It's too big to fit on the disk.
My guess is that you are using the Best Performance encoding setting (that's iDVD's default setting). The Best Performance encoding uses a preset bit rate; given the size of your project the total space required at that fixed bit rate exceeds the capacity that can be written to the media.
The High Quality and Professional Quality settings use a variable bit rate that is calculated at the time you burn the disk and adjusted to fit your project on the disk. Those settings can actually fit a larger project on the media by adjusting the bit rate of the encoding.
iDVD - DO NOT Care about Gbs at all - only duration and this is movie time + menu time
Menu time can be 15 minutes or more if animated and complex.
Duration on DVD will depend also on the encoding quality chosen.
• Best Performances = maximum of 60 minutes
• High Quality = maximum of 120 minutes on a SL-DVD
• Pro Quality encoding = maximum of 120 minutes on a SL-DVD
I always use Pro Quality and very simple menu - no video buttons, animation or audio on my menu. I prefere Old Theme - "Brushed Metal" (and the sub-menu of this (no video/picture button)
Yours Bengt W