24p, 30p, 60i

kairosmatt wrote on 3/18/2008, 8:20 AM
I've been reading some older posts, but can't quite figure it out-and its making my head hurt!-so I thought I'd ask.

I've been making 60i DVDs out of 29.967 PN material, and found that preferable than shooting in 60i (because when I do that, I get really obvious interlacing).

I've also done 23.967 PN to 60i DVD and this hasn't been bad either.

Now my project has both 23.967 PN and 29.967 PN, and again going out to 60i DVD.

1. Should I edit on a 23.967 or 29.967 timeline?
2. Will mixing different framerates on the same timeline have weird results when rendering?

Thanks
kairosmatt

Comments

johnmeyer wrote on 3/18/2008, 9:05 AM
First 60i and 29.97 NTSC is the same thing.

Second 24p and 23.976 is the same thing.

(Well, in most cases, but it gets too complicated to be more specific).

In both cases things are rounded off because of the way NTSC color TV drops one frame every 1000 frames (well, it doesn't actually drop the frame, but the numerical count IS dropped).

Third, you can put whatever you want on a Vegas timeline, and it will all be converted to whatever Render As settings you choose. Most of the time, you want those settings to exactly match what is on the timeline, so if you edit 23.976, you should render to 23.976; and if you edit 29.97 interlaced, then that is how you should render.

I have seen projects that cut between these, and generally I think it is artistically a bad decision, although like anything artistic someone who is gifted can break the rules and in doing so create something brilliant.

But for most people it will look like heck.

If your different 23.976 and 29.97 segments can be put into different chapters on the DVD, then I would render each to a separate MPEG-2 file, using the template that matches native fps, and then drop each of these into DVDA. They will both play correctly, and everything will look great.
kairosmatt wrote on 3/18/2008, 9:24 AM
JohnMeyer,
Thanks for the reply.

Unfortunately I can't have different chapters, it all has to go out as one. The company receiving the DVD will then broadcast it on cable (I know this is a really awful lossy process, but their DVCAM tape deck is busted, everyone else is giving them DVDs and we're all in the Bahamas we're its hard to get stuff fixed or replaced for a reasonable price). Plus the material won't divide out so easy.

Given that it will have to mixed, I think it would be better to put everything on a 29.967 timeline, since that will be the final output, but I'm not 100%

GlennChan wrote on 3/18/2008, 9:50 PM
Put everything in a 29.97 interlaced timeline (e.g. use the right preset for Project properties). Your broadcaster will want that. I don't know of any who don't broadcast in 29.97 (unless it's 59.97p HD).


2- What's 29.967? You mean 29.97 right? (Well technically it's 30 * 1000 / 1001, but that's too unwieldy to say.)
Spot|DSE wrote on 3/18/2008, 10:57 PM
What's 29.967? You mean 29.97 right? (Well technically it's 30 * 1000 / 1001

I would think it's a typo of 29.976
kairosmatt wrote on 3/19/2008, 6:54 AM
Yeah, I've been typing it wrong.

"Put everything in a 29.97 interlaced timeline"
Glenn, thats what I was looking for, a simple answer. I keep going in circles with this stuff trying to out-think myself.

If I'm going to DVD out, it should be set to lower field first right?
johnmeyer wrote on 3/19/2008, 9:16 AM
DVD can be encoded either upper or lower first. It doesn't matter. I'd pick whichever matches the bulk of the material on the timeline. Field reversal is dirt-simple, and I think that Vegas handles it correctly. The simple way is to just throw away the first and last field and then combine the top field from one frame with the bottom field of the next frame (or vice versa). Very simple stuff.