how to find final size of vob(s) using m2v+ac3+subs

[wazzzaaa]

Im using the big3 but i find out that my final dvd sometimes oversize so i like to find out how to find out the size of vobs by using the size of .M2V + AC3(or DTS)+ SUBS.

For example, i just finished ripping DVD, the main movie created by scenarist is 3.50 GB with AC3 and DTS. Yet this is different if add up all the size of video+audio+subs = 2.31 GB of .M2V + 1.35 GB of AC3&DTS +11 MB of subs = 3.67 GB. So its somehow different.

So please help if someone can figure out how to predict the size from M2V files, audio files and subs ...TIA

[wazzzaaa]

UPdate:

actually is undersize not oversize

Also is it just like size M2V+AC3+SUBS = VOBS?

[Skynet107]

Problem is, DVD use specifies that 1 meg is 1000000 bytes not 1024000 bytes. This is probably where your confusion lays.
If you have a aprox 4 gig file reported by Windows as say 4,294,967,296 bytes this will be reported by DVD software as nearly 4.3 gigs, not around 4 gigs which it really is.

[wazzzaaa]

Nah its not about that. The DVD i made came 300 mb short and its because of incorrect bitrate calculation. And i already find out whats the correct bitrate to make full dvd 4.38 GB. But this is the problem now: since i can change the bitrate and find out the video size before encoding, I will know all the sizes of all my videos+audios and subs even before encoding as well. But I want to find out how to predict the vobs that scenarist will make using those 3 elements. And so far I have no idea yet how to use 'em in some kind of calculation

[SaSi]

300Mb out of 4.36Gb is quite a lot. I have never had that much error authoring.

The subtitles, when encoded, take up very little space. I actually ignore it as it is in the 3-5 Mb range.

The VOB contains all of the .m2v and all of the .ac3. Before multiplexing them, Scenarist has to packetize them (produce Packetized Element Streams) which adds just a little overhead.

Multiplexing introduces yet another small overhead, with pack headers repeated every 2kb or so.

Therefore, I can't imagine how you end up with a set of VOBs that's smaller than the AC3 and .m2v files.

Is it possible that there is a mistake in the sum?