"Loss-lessly" IVTC-ing a DVD?

[Hurin Thalion]

Hi All,

This project began as an effort to add subtitles to a Region 2 anime DVD. I was sucessful in doing that. However, the Region 2 DVD is very poorly mastered. When played back on a computer, it shows a ton of interlacing artifacts no matter what DVD player software or settings are used. It looks quite a bit better on a table-top player, but some jumpiness and other artifacts are still present. Analyzing its cadences and frames, it's really a mess.

I recently decided to try to IVTC the DVD. And, I think I've been largely successful. Despite the movie constantly switching between film and video modes. . . and only about 30% of it being detected as "film" in DGIndex, TMPGenc seemed to do very well IVTC-ing and extracting the original frames from the interlaced mess. I had to tweak one sequence, but otherwise, it's good.

I'm wondering however, did I do it right? And how can I best re-encode without degrading quality?

Here's my process so far (I'm *very* new to this):

1. Decrypt/Demux the DVD using DVD Decrypter.
2. Open the M2V file in DGIndex. Save it as D2V project.
3. Open the D2V project in TMPGEnc. Select source as interlaced and Film. Choose IVTC. Double click-IVTC and run the automatic procedure. Tweak a few frames.
4. Encode within TMPGEnc with "Very High (slowest)" Motion Precision and 8000kbps CBR.

I'm concerned that this will suffer from a "copy of a copy" syndrome. . . or that I'm going to lose something from the original. Obviously, some loss is inevitable since I'm compressing it all over again. But, well, like in the case of a JPEG, is it possible to set compression to "none" (or near it). . . so that it's really just putting into MPEG format without compressing it all over again. Does that sound dumb? I realize I've gone from MPEG --> AVI (sorta, used DGIndex project) --> back to MPEG. But I'd like to limit the amount of damage done to the original video by this process.

Turning up the bitrate seems like a no-brainer. But, I'm not sure if I should be doing CBR. Flask reported the bitrate of the original demuxed video stream at 9200kbps. But I'm not able to get it that high in TMPGenc (seems limited to only 8000).

Any and all tips will be appreciated. I've spent roughly 300 hours on this DVD (generating subtitles, timing them, motion menus, etc.). It's a labor of love. Now I don't want to screw up its video at the finish line!

Thanks!

Hurin

[Hurin Thalion]

Woops, should this have been in the DVD Authoring area?

Thanks,

H

[dbloom]

(edit) forget what i said before this edit (I cleared it out), I misread your post...

There is no way to IVTC without reencoding the file. Still, the benefits or worth it.

IVTC is one of the few things that can make a reencode BETTER than the original. Although it won't help on interlaced TV's (except on DVD players with the chroma bug :D), it will look a lot better on progressive scan TVs or a computer.

While you technically lose detail, more detail is visible when played back. It's kind of like noise reduction - you lose some but it still looks better. Go for it.

[Mug Funky]

i'd be super-careful about maintaining AV sync when doing this, but go right ahead if the original is crap and you think you can improve on it. while you're at it, you might as well run some filters on to improve subjective quality. check the avisynth usage forum for inspiration there.

can i ask which anime it is? if only ~40% of it was IVTC'd in the original encode, i'd say it's probably from Gainax :)

don't be toooo worried about transcoding video - you lose a few high freqs, and theres some rounding error, but it's nowhere near as nasty as transcoding audio... so if possible try to keep the audio track you originally ripped from the DVD.

[Cyberia]

Moved to a more appropriate forum.