VOB file questions

[tmh]

I have a homemade DVD that I want to change a bit. Over in the "editing" forum I got some good advice on how to actually edit the mpeg2 files as I want. Now I have a couple moe general questions.

First, when I look at the files on the disk I see VTS_01_1, VTS_01_2, ... up to 5. Fine, I looked around here and found out that VOBs are kept to less than 1 gb so it need to break it into several files. However, when I double-click on any of these VOB files the entire video plays start to finish. Is this "normal" or might it indicate a problem?

Second, how do I get theVOB file(s) in a form that is editable like mpeg2? Do I need to open all 5 of these VOBs to edit or are they linked in some way that I open the entire video at once?

Thanks.

[Epicurus8a]

Use DVD Decrypter (IFO mode/no file splitting) to rip your DVD and get one large VOB.

You can use Virtualdubmod to re-encode your VOB to AVI. If you really need an MPEG2 file, de-mux the VOB with Rejig; then mux the files to MPEG2 with TMPGEnc (use the MPEG tools feature). AVI works better for editing, though.

[tmh]

Thanks. If I use Vdubmod to convert to AVI, is there a loss of quality? Then I'd make my changes the re-encode with TMPGenc, right? Then author then burn.

Sound like the correct process?

[yoda313]

Hello,

Most conversions have SOME quality loss. If at all possible it's best to go back to your ORIGINAL source and start again. That will ensure the BEST quality for your new project.

Your best bet is to use the same bitrate as the source file to ensure quality is kept similar to the source.

Kevin

[Epicurus8a]

As Yoda1313 states, there will always be a loss in quality when converting files. But if you can't re-capture the master in the format you need, you might not have a choice.

AVI is better suited for editing. But a few editors are made for MPEG only, check the requiements of your editor.

Once your newly edited file is complete, there may be no need for addtional conversions. But this depends on the requirement of your authoring software.

There are MANY variables to consider. Be patient and you'll be rewarded! This is the place to learn, so you're on the right path. Few members understand it completely, and many have been driven the brink (or is that: "to drink"). GOOD LUCK!

[tmh]

OK, I used Vdub to convert to avi but there was some noticable quality loss when I encoded back to mpeg2. Can't I just cut a small amount of the VOB then add in a new vob that is just the new photos converted to vob?

Also, when I ran the vob_1 through VDubmod it seemed to convert about 3/4 of the total video to avi. There are 5 vob's on the dvd so I am wondering what exactly VDub took and how? Do I have to put each vob section through VDum or can it find the others associated with the VOB_1 I put into it?

Thanks.

[daamon]

Hi tmh,

Can I summarise what I think is the case...

1. You've made a home-made DVD.
2. You now want to add in some pics somewhere between the beginning and end of the footage.
3. You don't say what authoring tool you're using - I think, from other threads, it might be TMPGEnc DVD Author (TDA)?

Based on the above, here's a logical process that'll avoid going to AVI and re-encoding back to MPEG2, but will be a bit long-winded:

1. Get the original VOBs on to your hard-drive.

2. In TDA, use "Add DVD Video" button to load your original VOBs.

3. Now use "Add file" to load the photos that have been encoded to MPEG2.

4. Now use "Add DVD Video" button to load your original VOBs again.

5. Select the first displayed VOB files. In the "Chapter Edit" screen, select the start frame for the 1st set of VOBs to the beginning, and the end frame at the point where you want the pictures to be.

6. Select the second displayed VOB files. In the "Chapter Edit" screen, select the start frame for the 2nd set of VOBs to the frame after where the pictures were inseretd, and the end frame at the end of the footage.

7. Now author as usual - the original VOBs won't be re-encoded, and you'll end up with a new set of VOBs with the pics where you want them.

Hope that helps. Good luck...

[tmh]

daemon, that sounds exactly like what I need to do. To quote the Scarecrow (wiz of Oz) "I should have thought of that in my brain".

I'll give it a try tonight and see what I get.

Thanks again.

[daamon]

Glad to be of help Mr Scarecrow...

Hope it works out.

The Wizard in Oz...

[tmh]

Daemon, it took me abou 20 min. to do what you said and it worked perfectly. I haven't purchased TDA until now, but that convinced me to buy it as my trial was running out. I'm not sure if some of the free Authoring programs work as well (or well enough for my simple needs) but I didn't see any that were so flexable on what I "fed into it".

I now need to decide between TMPGenc and Procoder for my encoder of choice. Procoder seems to do a good (maybe better) job on my DV files which is almost all I use as source. I think both do a fine job, so it's a choice I can't go wrong on.

[daamon]

Hi tmh,



I don't know Procoder, only TMPGEnc - whichever you go for, as you say, will be good so you can't go wrong. Personal choice - I'd say trial them both on the same bit of (decent length, say 30 minutes) footage.

Have a good New Year!

[tmh]

Well, I have completed the fix job on the video but the VOB files created confuse me. Here's why - I started out with 5 VOBs (VTS_01_1-5) copied of the DVD. The first 4 were just under 1 gb each and the 5th was 400,000 kb. They add up to about 4.3 gb. NOW, after only changing a VERY small part of VTS_01_1, then re-authoring with TDA I have 3 VOBs just over 1 gb and 1 about 350,000 kb for a total of about 3.4 gb. The changes made were to about 25 sec of a clip and wound up exactly the same total length (photos). Obviously that isn't what changed.

My process was to re-do the first 25 sec from scratch (AVI to mpeg2) then I inserted the short mpeg into TDA as the first file. I then cut the first 25 sec of what was the first VOB in TDA and just kept the other VOBs the same. I outputted to a Vidoe_TS folder from TDA. It took TDa about 15 min. to output. I don't know exactly what it was doing during that time. Anyways, the video plays fine but I'm not sure of the comparative quality yet. The original DVD was fairly poor quality so it might be tough to tell.

Does the authoring process in TDA cause ANY change in the quality of the VOB files? It wouldn't seem that it should but I really don't know exactly what TDA is doing to make the DVD compliant Video_TS files.

Thanks, as always.

[tmh]

bumping. I know someone is just dying to answer my latest question....you all must have just missed this by accident.

I need to burn the final edition tonight so I want to make sure I haven't screwed it up. Thx.

[mats.hogberg]

TDA doesn't (AFAIK) include a video encoder, so your video should be untouched. OTOH, it does some audio conversions, so you've maybe gone from LPCM audio in your original VOBs to MP2 audio in your new set?

/Mats

[tmh]

thanks, mats. Is there a program that can check what's in my VOBs so I know if TDa made the audio conversion? gspot doesn't do VOBs, does it? (not home so I can't try it right now).

[daamon]

I think the latest beta version of GSpot does.

I'm of the same thought as mats.hogberg - TDA (I don't believe) has a video encoder, so there'll be no re-encoding going on.

As for the audio, if I recall correctly, there's an option in TDA that says something like "re-encode the audio to match...(???)" - if this was ticked mats could be on the right track - it mayhave re-encoded the original WAV to MP2 coz your new MPEG (25 seconds) is probably MP2.