Hey guys, im in the process of backing up my first DVD, Blue Planet(sweet documentary of the world shot for IMAX), anyway, I am in virtual dub right now and and am wondering, why is there a first and second pass? under "job control" there are two jobs, Blue Planet-1st pass and Blue Planet-2nd pass, will this save as two files or one? since the DVD I am backing up is on 42 minutes long I chose to used the DVTool Data Rate calculator to calculate the best bitrate for making one 80 min, 700 MB disc. The question I am asking is probably stupid considering that in the guide the last step is "splitting the AVI", anyway just an explanation of what the "passing" does would be great, thanx a lot Rylenol
The first pass is to basically figure out how large each frame is. Then on the second pass the codec decides how to best spend the bits available and still hit the target filesize.
I have an issue regarding the target file size, I used DVtool to calculate the best Kbit per second, in the calculator i selected the time (42 min) the storage media(1 700MB 80 min CD-R) and 160Kb(MP3, very good) and the Kbit per second came out to 2115. So i plugged in this number for the bitrate under divx 5.2.1 compression in virtual dub. When I did both passes the first pass came out to 53MB and the second pass came out to 711MB(to large for a 700MB CD-R) How come the file came out big even though I entered the rite bitrate that DVTools gave me? Any help would be appreciated, thanx Rylenol
