Encoding a storyboard PGC: AVS output runs way too fast

[Dr.Khron]

Ok, one of my Simpsons DVDs has an storyboard special feature for one of the episodes... you can listen to the audio track while a series of stills flashes before you in real time.

It appears on the DVD as PGC with a run time that matches the main episode PGC(22:58 min)... so I ripped it with DVD decrypter, and indexed it. But when I encoded it, it ran each still as a frame at 29.970 FPS, so the entire clip was only 7 seconds long!

I would like to encode this as a separate AVI, muxed with a copy of the audio track. How do I slow down the source so that the encoder can encode it to full length to match the audio track?

[ChiDragon]

I don't know how images on DVDs are encoded, but at a guess, have you tried the newest beta of DGIndex that has support for frame repeats?

[Mug Funky]

AFAIK there's not much you can do to get the original timing back. in theory the timing for each still in the slideshow will be in the ifo files somewhere, but i don't know a way to recover it all.

you could just use assumefps and changefps to bump the stills up to the length of the episode, but they'll all go out of sync pretty bad. this may or may not matter for a storyboard, depending on how the slideshow was made to begin with (slideshows are a waste of time if you ask me...).

[Dr.Khron]

(slideshows are a waste of time if you ask me...)

Agreed... I was just fooling around with this mostly out of technical curiosity, to see if I could do it.


EDIT:
Tried the beta version of DGIndex... no difference.

[Mug Funky]

no version of DGindex will preserve the timing, because it doesn't read the IFO files.

however, i'm not sure which IFO or where inside the file and in what format the timing info is stored. i'm sure there's some tool that can get it out of there (maybe PGCedit or IFOedit?), but i haven't tried it :)

[Leak]

no version of DGindex will preserve the timing, because it doesn't read the IFO files.
Hmmm... I wonder if it's possible to use mplayer/mencoder to play the IFO and encode the result to a lossless format, and if that would preserve the timing information?

Or just use mplayer to output to PNG files, if there's some option to output a constant framerate by frame duplication (the harddup video filter sounds to be the ticket)...

np: Radiohead - Planet Telex (The Bends)

[Dr.Khron]

Well, the solution I came up with was to run the AVS at FPS = 238/(run time in seconds)

Assumefps(238,1378)

This makes it run the full length of the audio, but every slide has the exact same timing. Thats probably as good as I can get, but I wanted to know more about how timing info is stored in PGCs, so I posted about it on the IFO/VOB editor forum.

http://forum.doom9.org/showthread.php?t=124947

Got a good answer, too. Essentially, the timing data is stored in the muxing, which means its in the VOB, not the IFO. If it was in the IFO you'd expect one cell for each slide, which is not the case here. This means that ANY kind of demuxing (wether DGIndex or straight demux to m2v) destroys the timing information.

You can open the VOB with VobEdit and see the details... I don't know enough about how DVD cells are muxed to completey figure it out, but I'm learning.