Best way to edit VOB files without massive data loss/compression

[WaverBoy]

I have files ripped from a DVD that I need to make lots of edits on and re-burn to DVD without ending up with a massively compressed mess. What's the best way to go about this and retain as much original image quality as possible? It's a scan of a silent film print, so I'll need to edit the video and then add the audio track separately; it's already in DVD file format and ready to be demuxed from the overly compressed mess that my friend already attempted and remuxed to this new attempt.

My friend's original attempt resulted in a final .avi file size of 1.75 GB; the original combined size of the VOB files was 3.82 GB. A brutal chunk of data loss, resulting in a barely watchable mess.

Thank you in advance for your help!

[jagabo]

If you can live with GOP level edits you can use something like Mpg2Cut2 (free) and get no losses. If you need frame accurate cut use a smart editor that only re-encodes cut GOPs, like VideoRedo (not free, but there's a free tiral which might be enough for you to do what you want).

[manono]

I don't really understand. Do you have the source DVD, before your friend screwed with it?

it's already in DVD file format and ready to be demuxed from the overly compressed mess that my friend already attempted and remuxed to this new attempt.

That I don't understand.

And what, exactly, are you wanting to do?

If you can cut a short sample, we can have a look and advise better. I'd almost be willing to bet that if you know what you're doing, you could filter and then reencode the entire thing and wind up with something much better than your source.

[WaverBoy]

I don't really understand. Do you have the source DVD, before your friend screwed with it?

it's already in DVD file format and ready to be demuxed from the overly compressed mess that my friend already attempted and remuxed to this new attempt.

That I don't understand.

And what, exactly, are you wanting to do?

If you can cut a short sample, we can have a look and advise better. I'd almost be willing to bet that if you know what you're doing, you could filter and then reencode the entire thing and wind up with something much better than your source.

My friend received a DVD of a scan of a public domain silent film print from the Library of Congress, which he paid them to do. After he ripped the DVD, he converted the files to .avi, made edits, sped up the film, added a music track, and converted it back to DVD. The size of the finished .avi file after he was done with the edits and adding the audio was less than half the size of the original combined VOB file size, and it looks absolutely terrible; obviously there's gotta be a better way of doing it than whatever he did (I'm not sure of his exact workflow, number of re-encodings, software used, settings, etc.). I'm hoping that he can have another go at it, but he's not the most tech-savvy person, and obviously neither am I.

[LigH.de]

Using a scriptable frameserver like AviSynth, one would be able to avoid the loss of quality by saving intermediate compressed files. But learning how to script is not easy if you are not already used to programming; and you will have to re-encode your final cut anyway, which will surely cost a bit quality (but that may be less noticeable if done well).

If one is more used to working with physical intermediate video files and timeline video editors, expect these files to exceed the VOB sizes by a magnitude to avoid noticeable quality loss. AVI is just a container; the content makes the difference, and not only the selected codec, but also its setup (e.g. if considering something between MJPEG and Xvid, the best quality = the smallest quantization factor would be required).

[manono]

I'm hoping that he can have another go at it, but he's not the most tech-savvy person, and obviously neither am I.

Obviously. So you have the DVD? The original DVD from the Library Of Congress? And there's no retail DVD of the film available anywhere? What film is it?

As for a sample, open a VOB in DGIndex. Use the [ and ] buttons to isolate a section, one with steady movement. Then go File->Save Project and Demux Video. Upload the resulting M2V here or to some third party file sharing site. Or perform a similar procedure in the MPEG2Cut2 jagabo mentioned earlier.

[jagabo]

My friend's original attempt resulted in a final .avi file size of 1.75 GB; the original combined size of the VOB files was 3.82 GB. A brutal chunk of data loss, resulting in a barely watchable mess.

There are codecs that can compress video much more than MPEG 2 (DVD) so an AVI file that's half the size of the source DVD doesn't necessarily have to have a major loss of quality. But he may not have used such a codec and he probably screwed up in several other ways. Since this was a film source, if you can't get what you want with simple cut/paste editing, the best practice would have been to inverse telecine back to progressive film frames first, then edit/filter. Intermediate files (if necessary) should be saved with a lossless codec like (very large files) and then finally encoded as MPEG 2 for DVD.

You might also look for the film at archive.org. Their videos usually aren't the highest quality though.