Size problems with DVDAuthorGUI

[supernano]

I have 6 titles that run for a total time of 4hrs32min. I calculated the bitrate so I could fit them into a DVD5 and converted the video in the titles into elementary streams using the appropiate bitrate (2076kbit/s). After I add the titles to DVDAuthorGUI, the total size stays within the limit of the DVD size, but after authoring the project, the output ISO file is 6.3GB. Why is it adding so much space?
I added subtitles and a 1 frame menu but those shouldn't take up so much space.
Thanks.

[liquid217]

The 'statistics' function is rather 'dumb' so to speak. It simply adds all of the titles/menus together. The bottom line is that multiplexing has a little bit of overhead. (appx 5% or so). If you imported elementary streams, multiply your final number by 1.05 and it should get you somewhat close to the actual size.

[supernano]

I calculated the bitrate using the bitrate calculator on this site, which I believe takes into account the overhead, and the output iso file is over 5% larger, 4.3GB turned into 6.5GB. Could it be that the bitrate I used to convert the video was too small and somehow authoring converted it to a higher bitrate?

[liquid217]

No, the multiplexer wouldn't infllate the bitrate. you may want to try the alternate muxer, to see if there is any difference in the overall size (under tools).

[deadwing]

Just a pure guess-what audio track is on it? It sound like you may have PCM audio which would account for that kind of difference

[Bjs]

What tool was used to encode those video streams .

I use bbmpeg , and dvdauthorgui always displays 4000 during the mux stage , as thats what was used .

Ive seen some encoded by other tools , and dvdauthorgui displays 8000 .

Grab mediainfo and check what is reported about the m2v streams bitrate may track down the culprit .