"Bitwise" Copy of VOB File?
 

DVD's are encoded using the MPEG-2 codec. This is the same codec that HDV uses.

When I capture HDV from my camcorder to my NLE, it is not transcoded. It is just copied to the harddrive as an MPEG-2 file. No decompression/recompression takes place. It's very similar to copying a file from a backup tape.

Is a similar copying process possible with DVD footage?

I've been using TMPGEnc Xpress 4.0 to create audio/video files from unprotected DVD material. I then import these files into my NLE.

While MPEG-2 is a TMPGEnc format option, I believe this does not perform what I'd call a bitwise (exact) copy. I believe the VOB is uncompressed then re-encoded using an MPEG-2 decoder. I imagine this round of decompression/recompression causes a quality hit that may not be apparent on a computer monitor.

Does anyone out there know how to do an MPEG-2 lossless transfer from DVD to computer MPEG-2 file?

Thanks much. And please bear with my newness to this area of expertise :). Thanks again ;)!

I believe that the latest update to the Adobe Premiere Pro CS4 allows you to bring an unencrypted .vob file directly in to the video timeline. And verily the crowds cheered.

That should do it for you.

Andrew

Most NLEs can import your VOB files straight from the DVD without any re-processing.

If your NLE can't do this (some won't handle the VOB files right, some will if you rename them to .mpeg), then use MPEG Streamclip to do a bit-for-bit copy (File > Save as mpeg).

VOB are not Mpeg2 files, while they contain Mpeg2 streams.

Most of time, if you rename a .vob to .mpeg, you can play it, but only because the player does not really care for the extension of file.
There is a lot of flavour of mpeg and HDV files (mpegstream) are not technically equivalent to Mpeg2 found in DVD.

Encrypted VOB (from protected DVD) must be cracked first (copied to hardisk while unencrypted). this process does not change the video content, so there is no loss.

Then usually you have to Demux (split) video from audio, since VOB can contain AC3 or DTS audio or even several streams of audio. There could be too subtitle stream to be removed. Again, this is simple binary copy, so no recoding should be involved.

After that, the desired audio and video are Muxed (joined). Again no loss here.

But some converter are trying here to change the way video is encoded (to fit video into a DVD-R) , or simply by using codec that fits your NLE or device , by changing the IPB frame sequence/ratio This could change video quality.