View Full Version : Basic DVD questions


Mark Donnell
June 27th, 2008, 05:51 PM
Just a few basic questions - am I correct in believing that the final video files on all standard DVDs are VOB files, and that they are always authored from MPEG-2 files ? In other words, files such as H.264 and AVC files would have to be converted to MPEG-2 before going to VOB on a DVD ? Also, is MPEG-2 by definition an interlaced format or can it be encoded as full frames ?

Tripp Woelfel
June 28th, 2008, 10:20 AM
VOB files use MPEG-2 video compression with a variety of options for audio (PCM, MPEG, DD). Anything that's not MPEG-2 and of a file size that will fit on DVD disk (DVD-5, DVD-9) must be transcoded before burning.

Compression formats are generally independent of whether footage is interlaced or progressive. You can transcode interlaced to progressive, or interlaced to interlaced. You might be able to transcode progressive to interlaced but I cannot imagine why. I've never heard of anyone trying it.

Ben Longden
July 26th, 2009, 03:54 AM
You might be able to transcode progressive to interlaced but I cannot imagine why. I've never heard of anyone trying it.

I have and it looks bloody awful.

A nearby stringer shoots football in HD progressive then downconverts to SD interlaced for SD digital TV broadcast.

The legs on the players look terrible... flickering so much its like the shutter was set at a million..

Ben

Taky Cheung
July 28th, 2009, 12:10 PM
It's possible to transcode progressive footage to interlace. I shot in 30p, edit in 30p. During export, the mpeg-2 encoder will split the full frame into 2 interlaced fields so it becomes 60i stream for the DVD compliance format. It works very well.

Shaun Roemich
July 28th, 2009, 02:28 PM
720P60 downconverts VERY nicely to 480i. One of the reasons I bought into 720P instead of 1080i or p (until 1080P60 is available on pro cameras).