DVD exceeds Capacity : 3.9gb file turns to 4.45gb, normal?

Question

I am new to Adobe Encore CS6, as this will be my first DVD menu and authoring that I have done.
The project is for a feature length film. We have edited it all in Final Cut Pro and compressed it down at 8mbs in apple compressor. The feature length finished (.m2v) is (according to my Windows 7 PC) is 3.9gb if I right click and say "properties".
I load it into Encore with the accompanying audio file and then make a new timeline and drop both in. The video file still reads 3.9gb in size under the "projects tab". I then click on the "Timeline" tab in the upper-right...and it all of a sudden says my project is already 4.45gb large.
*this is rough the real version I want to burn has menus, extras, trailer, audio commentary, subtitles, etc., but for our purposes it seems that the big problem is just with the movie file itself*
I guess my question is WHY is Encore adding an addtional 0.5gb onto my file for just having a timeline? is this normal? how then should I estimate how large to make my compressed video file? i was certain if the movie was only 3.9gb that I would have plenty of space to still add my extra features and still fit it on a DVD-R (dvd5 4.7gb) and not have to jump up to a DVD-R DL (dvd9 8.5gb).
Basically my issue comes down to money. At a duplication facility, it costs twice as much to print onto Dual layered dvds and so I am trying to avoid this if at all possible.
Any info would be much appreciated. thank you,
Chris

Answer 1

Your solution will lie with Jeff's direction. Ultimately, you can only get on the disk what will fit based on the length of your movies, including extra content - video and audio - and the size of menu, especially motion menus.
I get confused about Encore's estimates every time this comes up. So once again, I tried to sort it out.
Basically, Encore says it is tracking GB in the build panel, but it is really tracking bytes. A DVD that is called "4.7 Gigabytes" is really only 4.38GB - it is 4,706,074,624 bytes. To get to Gigabytes, you divide by 1,073,741,824 (1.024 * 1024 * 1024). Which is about 4.38.
What this means is that if you read your file size as 3.9GB, it is actually 4,187,593,113 bytes. To make this confusing within Encore, Encore reports your file in the project panel as 3.9GB. But when it lists the amount of the disk used and free in the build panel, it is reporting bytes with "GB" after it.
I just did a no menu test with a 1.69GB m2v and 41.5MB ac3. Encore reports 526KB of ROM used (the size of empty rom), used as 1.91GB, and 2.79GB free on a 4.7GB disk. (Remember that these are all bytes.) Built to a folder, Encore reports that it is writing 1.89 GB (really bytes), and the actual output folder size is 1,891,278,848.
My recollection now is that it may have been only bluray that was the subject of comments about Encore padding its predictions of size on disk. What we are seeing here is no padding.
Here is a bitrate calculator that may help you understand more about the factors that relate to the bitrate of your movies. http://dvd-hq.info/bitrate_calculator.php#Calculator
I can't find my favorite at the moment, that plugs in some allowance for menus and motion menus.
You're going to need some trial and error since you don't know how much space you are going to use for your menus. You'll add the running time for your extra content (actual timelines) as if it were part of the main movie.