Vob2MpgPro: loss of audio on seek forward

[aurgathor]

I'm trying to make mpegs out of some DVDs, and I run into an issue wherein sometimes the resulting mpeg has no audio. (well, VLC can't play it) There may be several different issues, or different manifestation of one underlying issue, but one easily reproducible case involves the Pink Panther DVDs. The created mpegs play fine in VLC or Windows media player if they are played from beginning to end without any manipulation. However, if I want to jump from, say, 30 mins to 1:30 by moving the slider, the audio gets lost on VLC but the video continues to play. On WMP, everything just stops; on Winamp, that actually locks up Winamp. Without checking GOP recalculate, this starts around the 1:20 mark, (80 mins); with GOP recalc checked, it starts around the 1:50 (110 mins) mark. The mpegs are almost 3 hours long. DVDs were ripped with the last version of DVD Decrypter.

There was at least one other case with a different DVD where the audio was dropped even when playing the mpeg continuously, but I need to look that up to verify.

[PuzZLeR]

It sounds like a segmented VOB or a bad transfer of VOB -> MPEG.

I'm curious how you "created" the MPEG files. I have a hunch it wasn't done right.

Keep in mind, .vob files are not meant for standalone play like their equivalent .mpg version is. And it's not just a simple matter of changing the extension from .vob to .mpg either.

VOB files may contain segmentation and indexing that is for its native home in a DvD structure in conjunction with BUP an IFO files. Played independently from this structure, the VOB file, or renamed VOB file, will likely have trouble since all pointers will lead nowhere, and one side-effect is bad navigation among decoders. To make it work like a "video file" you need to properly transfer it properly (without need to encode).

There are several tools that can do this, and I personally recommend NeroVision, as post 6 in that other thread:

https://forum.videohelp.com/threads/327103-DVD-to-mpeg

[aurgathor]

Vob2MpgPro is a very simple tool made just for extraction, so I don't think it was an operator error, but here are the steps I just took to reproduce the issue:
a) extract files using DVD Decrypter in File mode
b) in Vob2MpgPro in IFO mode, select VIDEO_TS.IFO
c) verify settings:
- only ch28 is selected
- output a mpeg file per chapter is unchecked
- recalculate GOP timecodes is checked
d) click "Start Extraction"
result is a 7,063,504 kb mpeg suffering from the above described audio issue
(I also did one with GOP timecodes unchecked -- essentially same result, identical file size)

I also created an mpeg again with nerovision using the exact same set of files (not the .iso as the first time) -- the result is a 7,063,496 kb mpeg without the audio problems.

So I'm fairly certain that I'm not doing anything wrong.

[PuzZLeR]

Well, NeroVision solved your problem didn't it? I guess.

I've never analyzed resulting GOP structures with NV, however, wouldn't any disparity be a delta in the overhead after re-muxing, or removing any segmentation or index formerly in the VOB in the transfer to MPEG?

I've never used the tool, Vob2MpgPro, but hopefully someone more knowledgeable can describe any flaw in your steps (if applicable). But, as a hunch, you probably got the exact file size with Vob2MpgPro because it did nothing to make the changes necessary to the VOB file to make it work as a stand-alone MPEG.

Like I said, hunch.