I’ve now never rely on DVDA to reveal the amount of space needed. It does tend to err on the conservative. When getting to the 4.7gb limit on any rendering I have put my trust in the set formulas that abound here abouts AND that BitRate calculator.
On the other hand, DVDA also has to know and accommodate for the memory needed for menus, structures, graphics and any further complexities that you maybe designing-in, and which, by definition, aren’t within the scope of a pure Bitrate calculator, which just looks at the raw media files. I’m certain that that’s what “gives”?
Grazie