well im trying to fit 4 HD movies onto a DVD, and in WMV 3 are 5 GB and 1 is 3GB so if anything i would prefer them a little smaller
As iDVD transcodes the videos again, due to video DVDs (if you are talking about those) using the MPEG-2 codec, the QT X files you created will not determine the final size. As MPEG-2 is a less efficient codec than H264 or the WMV codec you have with your .wmv files, the resulting files will be bigger anyway. And as normal Single Layer (SL) DVDs only have a capacity of 4.37GB and using the MPEG-2 codec (with video DVDs there is no other choice), you will not get more than 90 minutes of video in acceptable quality onto an SL-DVD. You might be able to use Double Layer (DL) DVDs (7.8GB), but I guess the 18GB of .wmv files contain more than 150 minutes of video, though them being HD (720p or 1080i/p), they might contain less than 150 minutes of video, which might work with a DL-DVD, as video DVDs only use Standard Definition (SD - 480i or 576i) as a resolution.
Was that understandable? I sometimes might drift off a bit, especially with all the technobabble (wow, that word is even in the dictionary).