Mixed Frame Rates! UGH!!

streckfus wrote on 4/25/2009, 7:17 AM
I recently did a multicamera shoot, but one of the cameras somehow defaulted to 24p instead of 60i, which was the intended frame rate for this project. Didn't notice it during the shoot, but I sure did when I brought the footage into Vegas. (It's a mistake that won't be made again!)

Obviously Vegas doesn't support multiple frame rates within the same timeline, but I will need footage from both cameras for the final edit. Right now I plan to change the undersample rate for the 60i footage and render everything in a 24p timeline, but that obviously isn't going to garner the best results. Or I could render the project in 60i, but that's going to mess up the 24p footage. At this point I don't really care what frame rate is used for the final edit, as long as I can find a way to make the mixed footage look as smooth as possible.

I realize that there isn't a way to fix the problem entirely, but are there any other ideas out there? Is there a way to convert 60i to 24p or vice versa in a way that will limit torn frames? I know that it's possible to convert NTSC to PAL (24p to 25p) and other software applications allow for multiple frame rates, so I'd like to think that there's a solution to my problem, but I don't have the budget to purchase the kind of software/hardware that might make it possible.

Any way Vegas can be used to somewhat remedy the situation?

I'd welcome any suggestions. Thanks.

Comments

kairosmatt wrote on 4/25/2009, 7:33 AM
If your final output is 60i, set up the time line and all the renders as that.

Then just edit all your media as usual-including the 24p. Vegas will handle the conversion at final render.

If you really wanted to, you could use a tool like DVFilmaker to convert all the 24p to 60i (or vice versa) before hand, but I do not think that is necessary. The only trouble would be if you are creating a 60i Quicktime from Vegas-the field orders get switched around for some reason doing this. AVIs and MPEGs are handled correctly and you don't even have to think about it.

kairosmatt
streckfus wrote on 4/25/2009, 7:50 AM
Thanks for the tip...I realize that Vegas converts all footage into whatever project setting you choose, but my concern is getting the footage to look good. For example, if I brought 24p footage into a 60i timeline and rendered it out, the final edit would be 60i but it wouldn't look good (jitter, tearing, etc.) because the 24p/60i frame rates don't match. This happened with an indie film I worked on and the editor imported the footage incorrectly (he used FCP and apparently you have to manually tell the software how to import it....Vegas Capture is so much nicer!). Everything was supposed to be in 24p but he imported it as 60i, and some very awesome dolly/jib shots were ruined because of the step motion-type effect. That's what I'm trying to avoid.

But thank you very much for your info on DVFilmaker software....do you have a link for that app and an approximate cost? And my final render will be in AVI format so I won't need to worry about the Quicktime issue.

Thanks!
kairosmatt wrote on 4/25/2009, 4:38 PM
Streckfus:

Check out :
http://www.dvfilm.com/maker/index.htm


One of the things that is different about Vegas is that it doesn't do anything to your footage when you import it. It doesn't conform it to the project setting or anything like that. In fact, if you were editing in a 60i timeline and then wanted to change your project setting to 24p, no prob.

When you render is when any frame rate conversion is handled. I ofter render 24p source material in 60i MPEGs and DV AVIs and the results are perfect. Before you spend money, test a few clips and see what you think.

kairosmatt
John_Cline wrote on 4/25/2009, 4:51 PM
The problem is that the files are at a different temporal resolution and Vegas can't solve the visual disparity between them. It is relatively easy to convert 60i to 24p, but converting 24p to 60i will still have a 24 frame per second temporal resolution.

Since 24p is the lowest common denominator, I'd just set up a 24p timeline, drop everything in it, render at 24p (or 60i using pulldown) and call it art.
kairosmatt wrote on 4/26/2009, 3:02 PM
I understand that John Cline and others on this board have issues with the "staggered" effect of 24p, but if you're shooting HD 24p and downconverting to SD 60i, I think the resolution issue goes away, even temporal. Now, I realize that means that Vegas has to do some interpolating, but I feel it does a great job and you would be hard pressed to have an issue with it.

And I guess you could call it "art." Which, to my mind, beat reality TV (60i) any day!

kairosmatt
corug7 wrote on 4/27/2009, 3:17 PM
Vegas does a pretty good job of rendering 24p from 60i on its own. Set up a 23.98 timeline and drop your footage onto it. The 24p footage should stay 24p, and the 60i footage will create frames from selected fields. I just did this with a major (for us) project and the results were very good (you will lose some resolution from the 60i footage, but if you are starting in HD and delivering on DVD this will not be an issue).

In respectful response to kairosmatt, the issue of temporal resolution cannot go away (at least not in Vegas). Temporal refers to something that happens over time, and resolution refers to the number of frames. So, 24p has a different temporal resolution than 60i, and without sophisticated optical flow technology (and an insane amount of luck), we can't recreate the additional frames needed to increase temporal resolution.

You can, however, reduce the temporal information on the 60i files to be closer to that of the 24p files. If you have some time to experiment, you might try dropping Mike Crash's smart deinterlacing filter on the interlaced footage (and setting the deinterlaceing properties in your project prefs to none). I have had some really good luck with NTSC to PAL conversions using this method, so I don't know why it wouldn't work with 60i to 24P.