I've never done this before...where you have a single 4.7GB blank DVD and you try to squeeze down two files that total roughly 8GB's on it. The two files are each about two hours long each. I'm using TMPGEnc and it has a feature that initially showed me that the total size would take the project into the red zone, but later when I set my parameters for recording, I changed it to handle the two large files and it appears that it looks like it is ready to do that without throwing any big argument but I'm wondering, is that going to degrade the quality of each of them by trying to squeeze those 8GB's down to fit onto a 4.7 GB disc? I'm assuming what it will do is lower the bitrate to make it work
Hello - 4 hours on a DVD-5 brings the video bit-rate down to average of 2250 kb/s (assuming audio of 224 kb/s). It's doable, but quality will suffer - (it's similar to SVCD bit-rate, popular in years gone by).
So obviously DVD 9, Double-layer discs would work better. Amazingly, I have never used double layer discs, but I did just find out that my burner supports them. I'm going to go ahead and order some. Is there anything special about burning to them that I should know ahead of time? Thanks
Not really, find good quality disks, (Verbatim comes to mind) and you should be OK. You didn't mention how high the quality of the original 2 files were. If they're very good or better, your dvd-9 plan is good. But if they're just average, you may want to try encoding them at 1/2 D1 (352*720) on the DVD-5 and see if it's acceptable. (I'm only mentioning it as an option. I've used it in rare occurrences and in some cases, it solves the problem.)