Edit a DVD - can I avoid recompressing?
 

I have a project that is on a DVD and needs to be edited. The original material is no longer available. I can easily get the material into FCP using Mac the Ripper.

My question is getting it back to DVD again - will I need to recompress all of the files all over again with Compressor, or is there another way to do this where I could avoid compressing the material a second time? Wow - the wording for this is a lot more difficult than I thought, but I think you'll all get what I'm after...

Thanks.

Hi Nathan - firstly I would suggest MPEG Streamclip might be better suited to your needs than Mac the Ripper. Export out to Apple Prores HQ or Uncompressed and you'll get minimal generational loss.

Secondly, it depends what you mean by 'edit' a dvd. If you want to make changes to the content of the video itself, make cuts, re align audio, add graphics etc, then there is no way to avoid recompression. You'll need to make the changes and then recompress your m2v and ac3 files and author the dvd using these new files.

If you just wanted to take the content on one dvd, and put it on another dvd (e.g take videos from three different show reels on three different dvds so they could all be played from the same DVD, without changing/editing those individual tracks) then you can demux each stream using MPEG Streamclip and then just drop them into DVD Studio/Toast etc and you shouldn't need to re-encode them at all, and you won't suffer generational loss.

Mpeg Streamclip is free so I'd definitely check it out. Note, won't work on copy protected DVD's.

Sorry to disagree with Craig, but sure, it's possible. Just search for "mpeg2 editor" and you'll see many options. Here's a good one. A friend of mine uses it all the time to make basic changes without re-encoding the whole mpeg:

TMPGEnc - Products: TMPGEnc MPEG Editor 3

Not sure about what to use on a Mac, but you can look around. Mpeg Streamclip seems to have some limited editing ability, but I haven't tried it.

It really does depend on what you mean by edit. If you simply mean chop some bits out, including the audio then by all means use an MPEG2 editor, but it you want to do some real editing and moving things around with different audio etc etc then it's better to take it back to FCP (as Craig said). The program Vito talks about is Windows only anyway....

Yeah, sure. If you want to do anything beyond basic fixes, I would agree with Dave and Craig. You'd find it much easier to just import, re-edit, and take the recompression hit when re-exporting.

Thanks for your replies--

Yes, this will involve some very significant editing, so I probably will need to get it into FCP. I'll check out StreamClip - I think I have that already anyhow.

FYI, this is not a copy protected DVD, so there aren't any limitations in that respect. I'm just hoping to keep as much video quality as possible.

Thanks.

--Nathan Lawrence

MPEG Streamclip allows you to export clipped m2t and ac3 files from the original DVD. You can do a crude edit this way although the circumstances where it will look good are limited. The file isn't re-compressed just clipped.

If I do have to recompress, how bad should I expect it to look? I will be using Compressor for all of the m2v compressions.

I would suggest surprisingly not bad, unless your initial DVD has banding/blocking issues which you notice already, which will get worse (or you are needing to do additional colour correction, which will degrade the quality further) a single generation of DVD compression (assuming you rip the original to an uncompressed or low loss compression codec like Prores) will turn out pretty well.

The times I have done it, your average user would never notice. Essentially you should be able to tell why you are editing it, because once it's ripped an in quicktimes, it's just like regular originating footage.

Great - this is helpful. Basically, I need to remove some shots that include annoying Powerpoint graphics and insert the text/graphics that were SUPPOSED to be included. It sounds like it is quite doable with my current set of tools and will be acceptable to the client.

Thanks for all of your responses.

One thing you DO have to watch out for is Quicktime induced gamma shifts... These can be tricky to deal with and can make a real mess of your footage if you don't know your workflow.

Nathan -- I'm doing something similar right now. Creating a compilation DVD for a trade show and have been given video from a lot of different sources in HD and SD from DVDs, pulled from Vimeo, and received as QT files. Most of it is on DVD. I am using Mac the Ripper to extract the video off the DVDs, and MPEG Streamclip to create Quicktime files. Then it is onto the FCP timeline for minor editing, encoded via Compressor and into DVDSP. I created a quick test DVD and it seems to work fine. Definitely need lots of working room on hard drives!