Preview Selected Cell questions

[laserfan]

Presented with the "Create Layer Break Position" dialog for a DL DVD burn, I have 4 green stars (Excellent) to choose among for my layer break, but for only one of these is the "Preview Selected Cell" available; for the other 3 this button is greyed-out--apparently only lines with "Start Times" can be previewed:

 

50/50 VTS_03_0.BUP N/A...
50/50 VTS_04_0.IFO N/A...
50/50 VTS_04_1.VOB N/A...
50/50 VTS_04       N/A        1        1        1        1/1        00:00:00        No

 

Note the last two are shown as the same LBA of 2027402 -> 2027408, but only the very last line item was available to Preview. Questions:

 

1. Given the first three don't have any Video to Preview, should e.g. the BUP be the best choice? Indeed it appears these are listed in order of desirability? That to have the layer change at a BUP or IFO is ideal cuz no video?

 

2. These VTS_04 that appear to be referring to the identical file are confusing to me. If these were the only two choices, would it be best to choose VTS_04_1.VOB? What's the diff with the next line VTS_04 in this context?

 

Thanks in advance for any enlightenment.

[Cynthia]

1. Best is to cut between two VTS; so I would go for the VTS_04_0.IFO

 

2. Looks to me as the VTS_04 holds no video. Might be a fake VTS that's been removed during the rip There is's even a menu video file for that VTS.

 

IFO/BUP files are text based script files. You can use IFOEdit to look at them and you get an idea what they do/contain.

 

http://www.ifoedit.com/

[laserfan]

1. Best is to cut between two VTS...

Oh, yes I get it now.

 

2. Looks to me as the VTS_04 holds no video. Might be a fake VTS that's been removed during the rip...

Well it's not a rip, but a VIDEO_TS I made myself using a program called AVStoDVD, and yes it has a menu, then multiple TV episodes. But what is odd to me about ImgBurn's display is that there is no actual file called simply "VTS_04" in the titleset, just two VOBs specifically VTS_04_1.VOB and VTS_04_2.VOB. So I'm not sure why ImgBurn lists it at all, unless it is some peculiarity of the authoring method used by AVStoDVD.

 

No matter I guess, it's just that I burn DL DVDs so seldom that this display puzzled me to want to understand it better.

[LIGHTNING UK!]

List entries where an actual file name is specified means the LB will be at the start of the file itself.

 

Other entries are based on data in the IFO and will point to a certain Cell in a certain PGC within the VTS set the IFO applies to.

 

i.e. VTS_04 = an entry based on what's written in VTS_04_0.IFO - and will ultimately be a sector within VTS_04_0.VOB / VTS_04_1.VOB / VTS_04_X.VOB etc.

 

Only the ones based on data in the IFO can be previewed. They're the ones pointing to actual video data.

 

Generally speaking, you're far less likely to be offered LB positions at the start of files than you are ones based on IFO data.

[laserfan]

Excellent, many thanks LUK for this detailed explanation. I'm going to add it to the "Self Help" file I keep on this stuff!