MPEG2 files have a flag in the header that tells the DVD player which field order was used when the file was encoded, you can use either. By the way, AVI files do not have this information in their header and can cause problems if you get it wrong..

The most important part about field order on DVD's is to ALWAYS have all media on your TL be the same. If you mix upper & lower field first footage it will look really really bad for one of them.

" If you mix upper & lower field first footage it will look really really bad for one of them. "

Are you sure about his because I'm pretty certain I've done this more than once and nothing has blown up. I've always assumed Vegas just sorts it all out with no drama at all.

Bob.

The main concern is that the DVD MPEG field order should match your sourc material. DV AVIs are LFF, but many uncompressed formats are UFF. You will probably notice that most Commercial Movie DVDs are UFF.

Dave T2

This is where I get really confused:-

[i]John_Cline : By the way, AVI files do not have this information in their header[/I]


[i]DaveT2: DV AVIs are LFF, but many uncompressed formats are UFF.[/I]

I hate this stuff, I really do.

Grazie

Grazie,

I agree. The problem arose when the DV AVI format came along. Before that, most digital video was 720 x 486 UFF. Then for the consumers, they created the DV format which is 720 x 480 LFF. The idea was to save 6 lines of video and to standardize a format. Unfortunately, all they did was confuse the issue. With slower computers, the six lines could maybe make a difference in performance, but now that is a non-issue.

Dave T2

If you mix upper & lower field first footage it will look really really bad for one of them. "

Are you sure about his because I'm pretty certain I've done this more than once and nothing has blown up. I've always assumed Vegas just sorts it all out with no drama at all.

--------------

there is a setting in the project properties...something about adjusting timeline video to best match project properties...the help file indicates that checking that option will adjust interlacing and other clip properties to match the project properties.

You are all making this sound way more complicated than it is.

First, John (Cline's) recommendation about rendering to MPEG-2 is correct: it doesn't matter whether you render Upper (top) field first or Lower (bottom) field first.

Second, Vegas is at rev 10, and the engineers long since figured out how to correctly handle upper and lower field first media on the same timeline. So, don't worry about it.

The only time it matters, and the only time you have to take action, is when the field order gets incorrectly reported to Vegas. In this case you have to right click on the media (either in the media pool or by right clicking on any of the media's events on the timeline) and then manually change the field order there. I have seen the field order get incorrectly reported in AVI files that were generated by frameservers, by really bad encoders (i.e., from video you receive over the Internet from unknown sources), and other similar things. By contrast, if you put video on the timeline from nothing but your various cameras, you should never have to worry about this.

Finally, there is a very simple technique that only takes a few seconds, that will immediately show you whether you have a problem. I can't remember it off the top of my head because I use a different technique, but it involves temporarily setting the project properties to double the frame rate. I'm sure someone can post it.

OK John, I follow all your advise, and I get excellent DVDs. Now here's the thing, and I'm not worried about how I look by asking this: When I have finished up doing everything, slomo, colour grading, whatever, is it BETTER, quality, sane bit rates to:

A] Keep Fields for MPEG Encoding

. . OR . . .

B] Deinterlace for MPEG Encoding

I've always wanted to ask this.

Cheers

Grazie

i think deinterlacing always reduces resolution...at least the way Vegas does it (interpolation or blending)

Thank you.

Grazie

Deinterlacing always reduces resolution, that's part of the process.

Like I said, MPEG2 files include the field order in the header of the file, AVI files do not. DV .AVI files are always LFF and Vegas is smart enough to know this. Any other AVI file can be either LFF or UFF and it's up to you to figure it out. Regardless, you can freely mix UFF and LFF on the Vegas timeline as long as you have correctly set the field order of each clip.

I believe that the field order determination method to which John Meyer refers is to change the timeline to 59.94 fps (or 50 PAL), Vegas will then place each field as a separate frame. Zoom way in on the timeline and step through the frames one at a time, if the field order is correct then each frame will appear to be sequential in time. If the clip's field order is set incorrectly, then one frame will appear to advance in time and the next frame will appear to go backwards in time. It will then alternate between going forward and backward. You can test this by setting the field order to the opposite of what it should be, DV is known to be LFF always, set it to UFF and observe what happens.

Checking field order is why I keep one, lone CRT monitor in my suite, it's pretty much the only way to make absolutely sure that the field order of the final DVD product is correct.

Deinterlacing negatively affects both spatial resolution [i]and[i] temporal resolution. You will lose some vertical resolution (spatial) and your footage, which has 59.94 (or 50 PAL) individual images per second will be reduced to 1/2 of that. (Temporal resolution.) Unless you really [i]need[i] to deinterlace, which is usually for displaying on a progressive computer monitor, then leave it interlaced.

OK John, I follow all your advise, and I get excellent DVDs.When the target is a DVD, never de-interlace. It's that simple.

The only time to de-interlace is when rendering for upload to the web. Most of the time, if you simply use the presets for MP4 (one of the preferred formats for uploading to the web), you'll get great results. Of course if you are trying to wrangle the absolute best result when uploading to the web, you can read through the 200+ posts in this thread:

Vegas to Youtube, Vimeo, Web -- A New Look

You'll find an amazing array of geeky solutions (the kind of stuff I love) that will do a slightly better job at converting interlaced material into progressive material. However, if you just let Vegas do this -- or if you just let your computer's playback software do this, you'll usually get results that are good enough for most purposes.

Happy, John Meyer and John Cline - thank you.

I can do a low-grade geek, sometimes, but the thought of reading a 200 post thread fills me with depression.

What would be neat if there was a simple - yeah, I know "simple" aint on the Menu - flow chart of what and WHY you would want to do something. I've seen this for colour correction and grading. I may very well wish to get web content to the best I can with the Vegas tools at my disposal. Maybe that's foolhardy?

Thanks again chaps,

Grazie

"I may very well wish to get web content to the best I can with the Vegas tools at my disposal."

As mentioned "somewhere" in that 200+ post thread, and repeated by John Meyer, the tools in Vegas do quite a nice job, and we have established that by putting annotated, comparative uploads direct-from-Vegas on Youtube. Comments are they're not bad.

The rest of what's in that thread is for the sake of doing the same thing a little better, hopefully as quickly, being the first to go there, making mistakes, learning from them, sharing, and getting to massage the inner geek a bit in the process. I haven't lost any sleep over it (I understand Nick has), but the uploads on Jerry's, mine, and Nicks pages have thousands of hits so far.

musicvid, get ready to be embarrassed - you've completely rocketed-off my "thank you" chart, in terms of being on my side.

See the post to that link - I just skimmed through it . . . . OMG!

Grazie