Standalone rip AC3 synch problem

[Tiernan]

Yet another issue to tackle...

I have a friend who's been recording what may be the last airings of MST3K for me on his Phillips standalone unit, with the idea that I could re-rip them from the DVD-RW's and re-author them (sans re-encoding) while at the same time removing the commercials (which had been recorded also).

This all seemed so easy, until I finally re-ripped the VOB's yesterday, and demuxed them all, only to find that the resulting m2v and ac3 file are complete out of synch (not even anywhere near the same length)

Am I doing something wrong (using VOBEdit, "rip all streams", "Split on new VOB-Id", etc.), such that I'm missing a step somewhere? Or is this a common problem with re-ripping VOB's that I haven't seen discussed?

[FOO]

Are they in a ratio of 5 to 4 ?

[Tiernan]

Ratio of 5 to 4? As in the length of the files? No. Or at least I don't think so. To be exact:

2:00:56:12 (3.98 GB) for the m2v and
2:01:50:25 (223 MB) for the ac3.

Does this make any more sense?

[FOO]

I was hoping it was easy. Oh well

How do you know they are out of sync ? How can you tell with separate files ?

Can you play the VOBs in anything where they are in sync ? Vdub ?

See what DVD2AVI says about film/NTSC content
See what DVD2AVI makes for an auduo file when you save project
the audio file will have a delay number in the filename.

Does the video play in the original recorder ? in sync

[Tiernan]

Verrrrry interesting...

DVD2AVI says that the audio file has a 414 ms delay. So... let me see if I can work this out...

Does this mean that the Phillips standalone (or any of them really) has a built-in delay, to account for the difference in the time it takes to encode MPEG-2 video and AC3 audio. Once the disc is done, the control structure that is burned on the disc automatically accounts for this delay, so that it can be played back properly.

So, the question must be asked, if I'm just wanting to re-author the VOB's outside of this structure (without having to re-encode), how can this happen?

Thanks for your suggestion about DVD2AVI. Very interesting...

[Faustus]

Find AC3 delay and have it remove the delay, should work then.

[FOO]

I never understood why the delay. Most commercial DVDs
are like that. They play in sync though. I think the VOB
structure has timing information that disappears when the elementary
streams are taken out. 414 ms is 12 frames . Maybe the video
decoder needs that to get initialized. MPEG2 frames are stored out of
time order so at least 3 frames need to be read before any can be displayed.
Dunno why 12 .

Did DVD2AVI say it was FILM ?

You are going to have a hard time removing commercials.

[Tiernan]

Thanks for all your help guys...

I got AC3 Delay and will give it a try.

In the mean time, I'm hoping I can find some app or another that will allow me to edit the m2v and ac3 files together, while still keeping synch. From what I've seen up to this point, Encore's editing capabilities are laughable at best, so... I may be out of luck if I have the expectation of using THAT software to re-author these standalone-created DVDs.

Then again, if I were to re-mux them (post delay correction), I should be able to edit them in any MPEG-2-capable editor, right?

I appreciate your optimism about this...hehehehe...

[FOO]

Sorry my friend,
Editing MPEG2 is my pet project. Nobody can seem to find a
way to guarantee success. It is a difficult thing to do.
The remaining problem is Mixed NTSC FILM

Some people give up and always capture in AVI and edit and encode.

Some people tolerate GOP accurate editors like TMPGenc which
only work well when you manually enter timecodes. This still
breaks with soft Telecine and is very slow.

Womble MPEG2VCR is excellent with video that does not have soft Telecine.
It is frame accurate. This means that it re-encodes around splices.
Never seen it miss.

VS7 and MS7 will "smart render" It should only re-encode around edit points.
I have caught it screwing up.

DVDShrink will correctly extract a section of movie. This is inconvenient
It has to be DVD to start with - (you have to author your capture to use it)
The result is a VOB ( if you wanted a MPEG2 you have more work )

The ideal solution would be for Womble to handle soft telecine.

[Tiernan]

Well, that didn't work very well...

AC3 Delay corrector indicated "file damaged" and gave up without really even attempting to make any change.

I was thinking that I might be able to use something like BeSweet to append the appropriate 414 ms of silence to the front of the AC3 file, but it doesnt seem to know how to do that without having a source and target file that are different from each other.

Quite apart from the commercial editing aspect of the project, should it not be possible just to append that 414 ms silence at the front of the file so that it synchs with the m2v?

There just HAS to be a better way to do this...