Transition hiccups

[John Rofrano]

[Kelly Griffin] “My source footage is 1080/24p being built in letterboxed SD (29.97fps)”

What do you mean by that statement? Your project is SD NTSC 4:3 and your source footage is 1080-24p?

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Kelly Griffin]

Hey John– Yes, my project settings are SD NTSC 720×486/29.97fps, and the footage I’m using was shot 1920×1080 23.97fps. Everything else seems fine except the anomalies I’m seeing in the fades between footage (and, of course, my audio gremlins).

[John Rofrano]

Kelly, If I were you, I would set my project to match my source footage. This will make everything edit much, much, smoother because each and every frame won’t have to be converted on-the-fly as you try and preview the project. Then I would simply render to the SD format that I need.

This is a much cleaner workflow and part of these glitches could be due to the mismatch of source and project formats and frame rates.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Kelly Griffin]

Okay, I kinda started suspecting that as soon as I wrote it.

Just trying to get used to ALL THESE FORMATS!

(Thanks John)

[Kelly Griffin]

John: So, actually, I should have said that I have a mixture of footage in 1920×1080/24p and some in SD 29.97, so I guess that’s why I figured as long as I have project settings set to one or the other (with final output to SD 29.97) I should make that my project settings (?). However, I just did a test render with project settings at the 1080/24p and all transitions were perfect.

Could you help me understand better the flaw in my (earlier) thinking?

THANKS!

[John Rofrano]

If you are going to work in a mixed HD / SD project and deliver as SD, I would try rendering the 1080/24p footage to NTSC DV Widesceen. That should fix everything. Then all of your footage will be the same size and frame rate. This is what other NLE’s would have forced you to do but sometimes they do that for a good reason… it makes everything work much easier.

What’s happening now is Vegas is interpolating the frame rate conversion on-the-fly. You are making edit decisions based on it, and then when the final conversion happens, things don’t quite line up. You could call it a bug since Vegas allows you to work this way, but if you have a deadline to meet, the path of least resistance is to conform all of your footage to match the project.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Kelly Griffin]

Makes total sense now. I guess until the “resolution independent” feature really is such, I’ll start thinking in those terms. Thanks for the help!

[John Rofrano]

[Kelly Griffin] ” I guess until the “resolution independent” feature really is such, I’ll start thinking in those terms.”

I don’t think it has anything to do with resolution. It has to do with mixing frame rates. 24p is missing 6 frames per second to get to 29.970. So Vegas has to create 6 frames that don’t exist. Then you are making edit decisions based on fake frames that aren’t really there (they are just synthesized for the moment to display something on the timeline). This is where the problems start creeping in. Vegas should handle this.

In going back and reading your original post you said:

When I do full-quality renders I’m noticing “stutters” in many of the transitions, and when analyzing them by stepping through frame by frame it looks like what’s happening is that when one or both of the video clips gets partway through the fade it just freezes for a frame or two and then “catches up” by dropping a frame or two.

You didn’t happen to disable resampling on these 24p events did you? Think about what you described… the frame seemed to freeze… perhaps Vegas was displaying duplicate frames to make up for the missing frames in going from 24 to 30fps?

~jr

http://www.johnrofrano.com
http://www.vasst.com