Ulead does native mt2 mode. Why can't vegas?

Laurence wrote on 9/23/2005, 11:01 AM

I just noticed that Ulead MediaStudio Pro 8 and their less expensive Videostudio will work with mt2 files directly. If you cut together a bunch of mt2 files, either one will do a smartrender whenenever possible saving both time and better quality. I believe they both use proxy files as you edit, so I believe that the difference would be more in output quality than workflow (as the smartrender would save a generation of decompression/recompression). Native HDV support is accomplished with a plugin on both programs. Why can't Vegas do this?

Comments

Marco. wrote on 9/23/2005, 11:07 AM

Because it is better to rebuild the GOP structure anew which enforces a reincoding.

Marco

jaegersing wrote on 9/23/2005, 6:51 PM

Marco, why is it better? I would have thought that you only needed to rebuild the GOPs where there are changes, and that if you do not rerender the unedited sections, the final results would be better.

Care to elaborate please?

Richard Hunter

Wolfgang S. wrote on 9/24/2005, 1:58 AM

It is better, because some standalones will have problems, with a GOP structure that is not constant.

I mean, the NLEs like womble or the MSP will close the GOP at the frame, where you make a hard cut. Right. But that means, that they add two i-frames, before and after the cut. And that brings changes to the GOP length.

In addition, there is the quality aspect too. If you render some part of the material, and other parts not, quality will be changed slightly between renderd and unrendered parts.

farss wrote on 9/24/2005, 4:52 AM

Correct me if I'm wrong here but isn't that technically correct.
At every cut there should be an I frame rather than a consistent GOP. I've already had one replicator cast serious doubts over masters from Vegas / DVDA over this very issue. Worse still is we have no way of knowing where the GOPs start, end result is on most players the chapter points are inaccurate causing the player to have to hunt back to the previous I frame.
Apart from that though editing any long GOP low bandwidth mpeg-2 stream doesn't sound like a good idea to me. Everyone keeps saying Vegas should cope with this because DVDs are everywhere. I don't think this is the issue at all, I think the public have been conned and conned big time, no one is educating them as to the very serious limitations of trusting their media to DVD. The good news is that DVDs are only last a few years at best, too short a time to have the cleint come back and want it edited. At least this issue is finally getting some attention in the local press.
Bob.

MH_Stevens wrote on 9/24/2005, 10:05 AM

Why can't Vegas be setup to only cut at the end of a GOP? Seems that would be such an obvious thing to do. GOP's are short enough that I see no reason why they should ever be broken up.

johnmeyer wrote on 9/24/2005, 11:20 AM

Everyone keeps saying Vegas should cope with this because DVDs are everywhere. I don't think this is the issue at all ...

I am definitely one of those people who have been saying this.

It isn't a matter of whether DVD is a safe long-term storage media (I think it is, but I agree we won't know for sure until many years have passed), or whether DVD video is as good as the original source (it obviously is not). Instead, my reason for SHOUTING about this so often is the fact that in almost every project I do, I need to use video from DVDs. For instance, clients come to me with DVDs that contains video they want used in their current project. Also, I sometimes give the client the original tapes, and only have a DVD backup. Many other scenarios.

Bottom line: DVD is where almost all the video created in the last five years ends up. If Sony continues to provide only partial solutions, this will not help their cause.