Have you actually tried to do what you suggested? I think you have it all figured out correctly, and it should work. Just set the project properties to 25 fps; click on the media or event properties and set the playback rate to 25/30 (which I guess is 0.83 -- I don't have a calculator handy). Disable resample. Done.

Is there some reason you think that this isn't working correctly?

Yes, because i cannot set
0,8333333333333333333333333333333333333333333333333333333333333333333,
and i think the 0,833 (which is the best value what i can set) will repeat some frames sometimes or skip if needed.

Dave: thanks for the tip. I don't need the audio, so it's a little easier.

Here's what I'd do.

In your 25fps Project...
1) Place your 30fps clip in a separate video track starting at timecode 00:00:00.
2) Disable Resample on the 30fps video event.
3) Calculate an endpoint. Let's say it's a 5 minute video event. 5 * 30/25 = 06:00:00 (you might have to do some integer math if you need to end at a specific frame)
4) Grab the right boundry of the 30fps clip and Ctrl-drag the end to the endpoint (i.e. 06:00:00 in this example).
5) Move the clip to the proper placement in your project.
6) Render as 25fps

...Jerry

PS: I'm assuming the clip is actually 30.000 fps (not 29.97 fps). If not, use 29.97 as your numerator. Edit: After reading johnmeyer's post below, I guess that should actually be 29.97002997002997 (or 30 *1000/1001)

First, I doubt you'll be able to find any duplicated or dropped frames because of the roundoff, Have you tried?

Second, if your input video is AVI, you can use an old hack utility called:

AVIFrate

to change the header of your video to any frame rate you wish. All it does is change the frame rate header in the file (the video itself is not touched in any way). Once this header is changed, the video file is treated as though it was shot at this frame rate. In your case, it will now play back at 25 fps.

Third, I assume that you are actually dealing with 29.97 fps rather than 30.0000 fps. If so, the actual math is:

(25/30) * (1001/1000) = 0.83416667

As you can see, the error due to truncation is much smaller than the simple 25/30 calculation.

Exporting a frame sequence will take a LONG time (have you tried this on a one-minute test section??) and I really don't think you need to do this.


... another idea that is much simpler than the frame export, will give you 0.00% dropped frames, will work much faster than rendering to individual frames, and will work with any input video is this:

Render your "30 fps" video to a lossless AVI file (use HuffYUV, Lagarith, or uncompressed), then use AVIFrate to change the frame rate to 25 fps. Work with that file instead. This gives you the same thing as using the image sequence, but I think it will go a lot faster and have fewer problems.

Ok, thanks for the answers, i will try your methods.
Avifrate seems the way to go with lagarith.
Anyway the easiest method would be if Vegas can enable for users changing source fps..

Years ago i sent in a feature request for exactly this functionality. I got a response back from the product engineer basically saying that if such a feature was implemented then they couldn't guarantee audio sync. I responded by saying that there were times when getting the video speed was the primary consideration and audio didn't matter, especially when dealing with video-only clips. I never got another response.

Maybe if a bunch of us put in the request ... ?