Timing errors extracting chapter audio from DVD

[Phantom_E]

I got the chapter times using ChapterXtractor_v0.962 and tried BeSplitv0.82 to cut the audio file into pieces.

The problem is that transcoding the VOB file into something BeSplit will accept (I tried WAV, MP3) introduces cumulative timing errors so that the last chapter is off in the neighborhood of 10 to 15 seconds.

I also tried a commercial demo that claims to do this. It works directly on the DVD and while it seems to give the same timing as ChapterXtractor it is off by several seconds in the output files. Due to the limitations of the demo I can't really tell if the offset error is a fixed or cumulative, but in this case I guess fixed.

Is there a transcode that will work for BeSplit?
Or is there something that can split the VOB and then transcode it?
Am I stuck with doing this by hand in Audacity?

Any suggestions greatly appreciated.

[Ghitulescu]

get the chapter as a whole out (lots of tools, like dvdshrink, vobblanker, pgcedit+fixvts etc.) then process the VOB as you intend to :)

[Phantom_E]

Ok, I'm confused.

The dvdshrink reauthor function lets me pull the 6+ gig "main" title off the disk (all in one big chunk) while discarding all other titles.

Which of the other tools you list would let me split the 6g VOB into 50 or so VOBs from the chapters I get with the pgc chapter timing dump from ChapterXtractor.

Errr, I might be able to turn the pgc chapter table into titles using pgcedit, but this would take me months if at all. Would it even work if I changed the IFO to say the middle of a title is now the start of a title?

[Ghitulescu]

So you need every chapter? Not a few ones?

[Phantom_E]

They are music video DVDs. I have collected about 30 over the years.

I want to turn them into mp3s instead of putting a DVD player in my car.

When I convert the big 6g VOBs I get into a 3 hour mp3 the timing goes off and the chapter split times from ChapterXtractor are no longer even close toward the end of the file.

[Ghitulescu]

Use vobblanker then, but you still have a lot of work to do, for each chapter you have to demux it, reencode it

[Phantom_E]

Ok, now I'm really confused.

Do you and I mean the same thing by the word "chapter"?

I thought vobblanker worked with what dvdshrink refers to as titles.

As best as I can figure out what I want is to separate pieces also referred to as cells (maybe?).

[manono]

DVDDecrypter can be set up to demux the audio by chapter, and it'll give you separate audio files for all the chapters in the source format (AC3, most likely, or maybe WAV). Set it up in IFO Mode and in the Settings have it split by chapter. Then in the Main Screen->Stream Processing tab, 'Enable Stream Processing', check the audio box (making sure it's also highlighted), and tick 'Demux' at the bottom. Give it a destination, begin the process, and then wait. Afterwards, though, if what's on the DVD isn't what you want, you'll have to convert it yourself to MP3 or whatever you like.

[Phantom_E]

Thanks to both for the suggestions.

I downloaded a the newest version of vobblanker and it does indeed seem to do what I want.

However, dvdshrink seems to have introduced some sort of error to the effect that chapters 1 thru 21 come out fine, 22 thru 37 write zero length files and 38 thru 51 are corrupt. Oddly the cell preview feature works.

I found out that this is also true when played with menus in powerdvd8 as well so it is unlikely to be a fault in vobblanker. All the menus work when the physical original is played.

If I play the vob by itself, without the menu system, I can scroll or just play the whole thing.

Any idea of what may have gone wrong?


Note: I used no compression and write vob as single file.

Dvdshrink also did this to the other files I tried.
I'll try DVDDecrypter when I get it installed.

[Ghitulescu]

If you put the original DVD in a standalone player and watch it on a TV, how many chapters/songs are? 51? 37? or 21 :)?

[Phantom_E]

There are 51.

This is also true with the virtualplayer and the original disk.

The virtualplayer with the backup behaves similar to the results of vobblanker. 22 to 37 go directly back to menu and 38 to 51 make an attempt to play then go back to menu. 1 to 21 play as they do with the original and do not return to menu at all but just go to the next song.

Note: the displayed menus go 1-16, 17-24, 25-33, 34-42 and 43-51. No correlation. It also does not seem to match up with the default 1gig vob splits.

PS: Same is true for a different disk, but the numbers are different. I have not tried the rest.

[Phantom_E]

PPS: I just checked with the virtualplayer and the backup the 21 song does NOT continue to the 22 song but goes back to menu.

On the transcode I did with BeSweet and the vob the songs are all there and the frame shift is consistant per song about .25 seconds, I'm guessing this is an artifact of transcodeing.

[Phantom_E]

I know a little about menu structure so I used a couple of utilities to see if I could figure out what went wrong.
Anyway here is what I found.

I got the start LBA of the cells from the VTS_C_ADT table in the ifo.

For the first 21 cells/songs the ADT table pointer points to a LBA "Navigation Pack"(x'01BB') block with a CellId matching the CellId table entry.

At the LBA address for the 22nd cell/song there is no "Navigation Pack" block.
Instead there is one LBA-1. This block is a duplicate of the "Navigation Pack" block for cell 21 including fields such as this->lba and system clock reference.
All navigation blocks after this point are also duplicates of the same cell 21 navigation block until the LBA address of cell 37.
At this point it starts recycling prior "navigation pack" blocks starting from cell 1.

The total number of blocks in the vob is correct so it seems like it is just misplacing these blocks instead of adding or deleting blocks.

I'm guessing that in stream mode (vob only with no menus) the decoders just ignore the navigation blocks.

[Ghitulescu]

This is also true with the virtualplayer and the original disk.

If you put the original DVD in a standalone player and watch it on a TV, how many chapters/songs are? 51? 37? or 21 :)?

Virtual player is not a standalone.

Wow, 180 minutes for a music DVD, quite a bad picture quality (or audio one) ....

[Phantom_E]

Virtual player is not a standalone.
Lol. I think I detect a trace of intentional perversity, but...
You were quite helpful. Thank you very much.


Wow, 180 minutes for a music DVD, quite a bad picture quality (or audio one) ....
The content is old, really old, even to me.
Digitized B&W film, shellac and vinyl.
Yes, It is heavily weighted to audio. This probably increases the perceived quality of the video.

[Ghitulescu]

Lol. I think I detect a trace of intentional perversity, but...

A bit of sarcasm was intended, but since you refuse to do this simple thing ...

[Phantom_E]

since you refuse to do this simple thing ...

There are 51.
This was my response to your question on standalone player with TV.

This is also true with the virtualplayer and the original disk.
Just an additional comment to the effect that with the original disk both methods work identically.