VOB2MPG chapter split - inaccurate?

[Toreadore]

I've been using VOB2MPG Pro for a while, and it is a fantastic tool. Today I wanted for the first time to edit some of my Vob2Mpg-generated files, and found that the split between two chapters seems to be inaccurate. The last second of the Mpeg_file1.mpg and the first second of the Mpeg_file2.mpg lacks some video, making the transition choppy. Anybody with similar experiences, or maybe a solution?

Brg, Toreadore

[ChrissyBoy]

Do you know with what tool the DVD was authored with? Or was this a commercial DVD?

Chris

[Toreadore]

The DVD was authored by me on a "LG RC 388" VHS DVD Combo recorder, set up to create a chapter mark every 5 mins. Any clue?
Tore

[hech54]

The DVD was authored by me on a "LG RC 388" VHS DVD Combo recorder, set up to create a chapter mark every 5 mins. Any clue?
Tore

DVD Recorders often create goofy file structures on their output discs....common knowledge. Also the auto chapter marking on DVD recorders is notorious garbage.
I'd just rip the disc with DVDDecrypter, remove ALL of those damn chapter markers, then take the segment you need in an editor of some kind. I would NEVER blame VOB2MPEG for not reading DVD recorder discs correctly.

[ChrissyBoy]

Also when chapters are defined at an automatic time interval you will always have this issue. Chapters should start with an I frame and be a closed GOP. If this is the case there is no reference to any frames earlier in the stream and so will start as expected. If the chapter point is at an open GOP then there may be reference to frames in the previous GOP - which of course do not exist when you only extract the chapter. This is what you are experiencing.

When chapters are defined at every 5 mins, or whatever, there is no control over the GOP structure at the chapter point. VOB2MPG is doing what is asked of it, in terms of chapter start and end points.... it is that the resultant mpeg starts with an open GOP which requires frames from earlier in the stream for reference.

See: http://documentation.apple.com/en/compressor/usermanual/index.html#chapter=18%26sectio...5%26tasks=true

and in particular the sections:

Understanding GOPs and Frame Types
More About GOPs and Markers
GOP Structure
Open and Closed GOPs

for a much more detailed explanation.

[Toreadore]

Thanks Heck54 and ChrissyBoy for your thorough answers. Sorry for my late follow-up....

My addiction to Vob2Mpg is due to its capability of beeing run in multiple instances concurrently, started from my selv-made .BAT files, which prompts me for at file name, and starts ripping from the selected DVD drive automatically. This way, I can rip multiple (for the time beeing 8) DVD's in multiple stations simultanously - leaving the mpg files nice and easy chopped up to 5 minutes files, to my hard drive.

Previously I have suggested to Chris a new function in a future version of V2M, where V2M disregards the DVD chapter mark, and creates its own Mpg-segments with configurable/parameterized duration/size. This will allow V2M to chop the mpg file in the correct way, sequring smooth transitions from one mpg to another when the files are edited together in a new video project. Is this within reach, Chris?

Brg Tore, Norway

[Toreadore]

Hi,
Any views on my above suggestion for a "custom configurable" chapter split? Will you consider such a solution?

Brg, Tore

[ChrissyBoy]

I have looked at this. By size is pretty straightforward whereas by duration is far more complicated. It becomes more of a mpeg editor situation. Would by size be any good to you?

[neomaine]

I have looked at this. By size is pretty straightforward whereas by duration is far more complicated. It becomes more of a mpeg editor situation. Would by size be any good to you?

You could always make a 5 (or whatever) minute chapter but give a caveat of it being +/- a few seconds so that you could properly make on an I frame. Say if it is 5 minutes, the start checking at 4:45 and up to 5:15 for an I frame to place the chapter mark.

[Toreadore]

I have looked at this. By size is pretty straightforward whereas by duration is far more complicated. It becomes more of a mpeg editor situation. Would by size be any good to you?

I think By Size will be a very interesting solution. The main objective here is to create mpg files with limited size where the transition from "A.mpg" to B.MPG" becomes seemless in my video editing software.
Of course i would love to see "by Duration" in a future edition as well, but By Size is by far good enough for now.
So now I look forward to the next Beta version

Brg, Tore

[Toreadore]

I have looked at this. By size is pretty straightforward whereas by duration is far more complicated. It becomes more of a mpeg editor situation. Would by size be any good to you?

You could always make a 5 (or whatever) minute chapter but give a caveat of it being +/- a few seconds so that you could properly make on an I frame. Say if it is 5 minutes, the start checking at 4:45 and up to 5:15 for an I frame to place the chapter mark.

Thanks, neomaine: If this makes the problem less complicated, I would certainly accept a 30 sec variation...

[Toreadore]

Hi,
Any chance that a "By Size" option as discussed above, will be released soon?