What are the issues editing 30 fps in Vegas?

will-3 wrote on 4/12/2010, 8:30 AM
1 - Can you edit video captured at 30 fps in Vegas?
(Like 1080p HD video captured on some cams.)

2 - What are the issues when you attempt to edit video captured at 30 fps in Vegas?

3 - Does Vegas simply "drop" one out of every 1000 frames?

4 - What about audio sync?

Thanks for any help on how to edit 30 fps HD video on Vegas.


TheHappyFriar wrote on 4/12/2010, 8:32 AM
Vegas doesn't alter the video file in any way & it will display the whole video unless you tell it otherwise. You should change your project properties to match the video file for best results.

Jay Gladwell wrote on 4/12/2010, 2:04 PM

I shoot (Sony EX3) and edit exclusively in 1080/30p (29.970) in Vegas. No problems with sync.

Why the concern?

will-3 wrote on 4/12/2010, 2:34 PM
Well I picked up that there were some issues with 30 fps.

Laurence said he uses Cineform to convert 30 fps to 29.97 fps... before editing... as I understand it.

When you do your editing at 30 fps... do you render to 29.97?

Are there any down stream issues?

Will 30 fps play in most players?

When does it become an issue to have or deliver 29.97 fps video?

Thanks for the help.
Laurence wrote on 4/12/2010, 2:36 PM
What Will is talking about is editing [i]exactly[/b] 30fps vs editing in 29.97fps.

What I've run into is that Vegas will do it two different ways depending upon your settings. By default Vegas is set to "smart resample" which means that it will try to avoid the jerkiness of dropped frames by resampling the image every 29.97 seconds. This will smooth out the motion but you'll get lots of double images on the various frames.

The other option is to go into each clip's properties and select the "disable resample" option. Then Vegas will simply drop a frame every 30 seconds. This is a much better option but it means going into the media properties of each clip and setting this option. It's not a global setting and it's a pain to have to do this.

Maybe there is a script that can automate this for you.

I only have trouble with this on my Canon camera and Neo Scene (or Neo HD) does the frame rate correction automatically for me when convert the clips. It also adjusts from cRGB to sRGB at the same time.

I don't mind this because working with the native .mov format is so inefficient anyway. Also, if I had chosen an AVCHD camera instead of the Canon, I would still be converting to Cineform just for the performance gains.
Laurence wrote on 4/12/2010, 2:40 PM
Another way to deal with this is to just set the project properties to exactly 30p instead of 29.97. I don't do this however because it is not my only camera. I need to match the 29.97 of my Sony HVR-Z7. I believe that Will would be in the same position because he needs to match the 29.97 of his EX-1.

Anyone with a Canon DSLR is going to have to deal with this same issue, at least until Canon releases the new and improved firmware update.
Laurence wrote on 4/12/2010, 2:43 PM
4 - What about audio sync?

Cineform Neo Scene gets around this by slowing down the footage 1%. It also slows the audio down so that it matches. There could still be issues if you used a Canon as a B camera and were recording a long continuous performance from several angles.
Jay Gladwell wrote on 4/12/2010, 3:04 PM

Will, to be very brief, almost to the point of being rude, you have nothing to worry about. There are no issues.

The best thing to do would be to try it for yourself--shoot, edit, render, burn, play. Then return and report.

Laurence wrote on 4/12/2010, 3:07 PM
Will, to be very brief, almost to the point of being rude, you have nothing to worry about. There are no issues.

My experience is that there are issues. When I first looked at a render with this issue, I thought it looked fine. Then I noticed it didn't seem as sharp as the source footage. I went through it frame by frame and saw all this ghosting and double frames. That was my experience at least.
Chienworks wrote on 4/12/2010, 3:12 PM
Disabling resampling should clear that up. With resampling on Vegas will blend frames to match the output frame rate. With it off, it will drop the occasional frame instead.
jeremyk wrote on 4/12/2010, 5:23 PM
Easiest way is to set the Playback rate property for the clip to 0.999. Stretch the audio track to match the video length and set 'Pitch change: Lock to stretch' to avoid any fancy stretch artifacts.
Jay Gladwell wrote on 4/12/2010, 5:32 PM

I'm curious. How is this the "easiest way"? I've never had to do this.

TheHappyFriar wrote on 4/12/2010, 6:32 PM
editing stuff that's 30p on a 30fps timeline has 0 issues. The issues arise when you don't edit actual 30p on a 30fps timeline. But if you're NOT editing 30p you shouldn't setup the project for 30p.
Jay Gladwell wrote on 4/12/2010, 6:36 PM

"But if you're NOT editing 30p you shouldn't setup the project for 30p."

That pretty well says it all, doesn't it?

farss wrote on 4/12/2010, 6:40 PM
Perhaps you've never looked very carefully at your footage :)

30.000fps is not 29.970fps so something has to happen. There's two alternatives and neither of them are going to produce prisitine video and the outcome is worse at low fps progressive video. Either Vegas is going to interpolate the frames or it's going to duplicate or drop frames. The former can lead to blurring, the later to jumps in motion.

Given that the real world speed and pitch difference between 30.000 and 29.970 is so close to be undetectable a simple approach is to just play the frames out at 29.970fps and adjust the audio sample rate.
Vegas provides a foolproof 100% accurate way to do this.
Match your projects frame rate to the source frame rate. Set the ruler to absolute frames and note the exact number of frames. Change the frame rate to the new frame rate. Ctl+Drag the end of the event to make it the exact same number of frames long. Render out. You may want to select an audio pitch shift method or in the case of such a minor pitch shift elect to ignore it. Make certain the Project's Audio Resampling is set to Best.
The only reason I don't use the clips sample rate method is I'm not 100% certain it is 100% accurate. It might be but the method I've described above is the one recommended by Sonic Foundry who wrote Vegas in the first place and I've yet to read anything from SCS suggesting there is a better, more reliable method.

I have used the same technique to convert many Artbeats 30fps clips to 25fps, rendering them out to 50Mbps MXF. Clearly slowing 30fps down to 25fps would in the real world create possibly obvious errors in speed however as the clips were only of rivers and clouds (no cars or people) and contain no audio this simple, free technique worked a treat. I could have done the task in AE which has superior time resampling but I don't like to use a sledgehammer to crack a walnut and there's an upside to the simple approach, the clips are longer, making them even better value for money :)

will-3 wrote on 4/13/2010, 8:59 AM
Gee Whiz... there are a lot of opinions and options on this :)

To keep it simple and avoid the issue of having to deal with both frame rates in the same poject...

How about just making it a rule to always immideatly convert any 30 fps footage to 29.97 fps... so you are always editing 29.97 fps. Then just delete the 30 fps original to save the disk space and avoid future confusion.

I guess Cineform will do that... or maybe one of the two Vegas methods mentioned here in this thread.

On this subject... Jay... are you mixing the two frame rates in the same project and leaving the Vegas settings in the default 29.97 fps ? Or what on mixed frame rate footage?

Thanks everyone for all the comments and suggestions. I'm going to re-read the thread more carefully to make sure I undestand all the methods and issues.

More comments welcome.

Laurence wrote on 4/13/2010, 9:41 AM
Just to be clear, you can set your project frame rate to 30p or you can set your project frame rate to 29.97. As long as it matches your footage you are fine. The problems come when you want to mix two cameras like say an EX1 and a Canon DSLR where one has a frame rate of 29.97fps and the other has a frame rate of exactly 30fps. Another problem is when you have a 30fps project and you want to burn a DVD or a bluray disk which will only work at 29.97. You certainly can work at 30fps with all 30fps footage and do a Youtube or Vimeo 30fps render and never see any problem at all.

The same thing with color. You can do a complete cRGB level project all the way to Youtube or Vimeo and never have any problems. The problems come when you have a mix of cRGB from a Canon and sRGB from an HDV or EX1 camera that you want to use in the same project. That one is easier as it is just a matter of sticking color correction on the different format clips.

When I use Cineform's HD Link to convert the footage, all my footage matches the industry standard 29.97 sRGB format. It does make it easier.
Jay Gladwell wrote on 4/13/2010, 9:47 AM

Will, I'm using the EX3, shooting 1080p 30fps--which is actually 29.970fps. So I've set up the Project Properties to 1920x1080, 29.970fps, progressive. The ruler is set at SMPTE Drop 29.970 fps. I like to K.I.S.S. ;o)

Unlike some folks here, I do not mix media, e.g., formats (don't need to). It's all the same format, with the exception of the occasional scanned photograph, when required.

DVDs are set up using the same properties, so it's consistent from beginning to end.

will-3 wrote on 4/13/2010, 7:46 PM
OK, now after all of this it sinks in... it seems I may have made an error in the subject of this thread.

When I said 30fps it confused some to thinking I was actually talking about 29.97fps... since often people say 30fps when they are actually referring to 29.97fps.

I actually meant 30fps and not 29.97fps.

As mentioned the Canon Sx1 is a 10mp camera that also records video at 1080p and 30fps... and that is actually 30fps... not 29.97fps.

As I look back over the thread it seems some were referring to 29.97 when they said 30fps...

So for the record I was asking about dealing with video that is actually 30fps... and in particular what issues should be considered.

I think the topic actually got addressed in the thread but wanted to clarify for anyone that read the thread in the future.

I should have been more clear in the subject when I started the thread.
Laurence wrote on 4/13/2010, 9:06 PM
Don't worry it is confusing. It obviously confused the design engineers at Canon who developed the high quality video modes on their still cameras. They seemed to have just assumed that 30p was, well, 30p!

The point I wanted to make sure that you understand is that with Neo Scene this isn't really an issue at all as HD Link automatically corrects both this unstandard frame rate and the unstandard levels range of the Canon still cameras and gives you very good quality video that conforms to a standard 29.97 (that everyone up until now has commonly called 30p) with color levels between 16 and 235 (instead of the 0 to 255 that they were before the conversion). If, like me, you are using Cineform anyway for it's previewing and rendering efficiency and it's ability to stay intact over multiple generations, then a Canon SX-1 IS is a very cool camera that works well. If you don't want to use Cineform, then the slightly unstandard framerate can be a problem.

This is the case with the Canon DSLRs and the SX-1 IS, except that it seems that Canon will likely correct this issue in the more popular DSLR lines. Unfortunately I doubt they will ever do this for the SX-1 IS which doesn't have nearly as many users.

In the case of the SX-1 IS, I love this camera. Like the DSLRs it has one button for stills and another button for video. The sensor size on the SX-1 is much smaller than that of the DSLRs so the depth of field isn't so shallow, but it still is pretty big for a video camera (1/2.8"). Instead of relying on manual skill, you can do tricks like press the photo button halfway down to set your exposure and focus, then hit the video record button to shoot video with those settings locked in. You can set the exposure and focus to lock in on faces. You can get a 40x zoom with a combination of optical and digital zoom that doesn't degrade the image because of the extra image sensor pixels. You can go all the way from that 40x zoom to quite a bit wider than most camcorders. The optical stabilization is very good and it has a mode that I love that just stabilizes vertically. This is wonderful for hand-held pans. The display panel is 16:9 and can articulate every which way. The only thing negative about this camera is that you are pretty much locked into using one of the professional Cineform products because of the color range and slightly unstandard framerate. This doesn't bother me at all because I use Cineform anyway, but for other people it could be an issue.