24p Standard footage playing choppy in Preview Window

DigitalOblivion wrote on 11/19/2003, 6:03 AM
I captured some 24p (standard) footage and found it played back choppy in the preview window.... 9 fps to be exact (@ full size/best). I thought 24p standard was still 29.97 frames a second...what would cause it to play choppy? I opened up a new project using the 24p template and it seemed to play fine.
?! Any ideas?! ....keeping in mind this is 24p standard.

Comments

Chienworks wrote on 11/19/2003, 6:53 AM
I would think that your 24p footage is just what it says, 24fps. This means that when playing it in a 29.97fps project each frame has to be resampled to match the project's frame rate. The proof of this would be that it plays fine in a 24fps project. As a little experiment, right-mouse button click on the clip and under Switches choose Disable resample. This should let it play back much smoother in a 29.97fps project.

Depending on the speed of your computer, full size/best is pretty tough on the cpu. My 866 P3 can't play 29.97fps at full speed in full/best.
farss wrote on 11/19/2003, 7:27 AM
For starters you cannot get genuine 24 fps onto tape.
What you would have on the tape is 24 fps with pulldown. If you enabled remove pulldown then the file on the disk is genuine 24 fps. If you bring that into a 30 fps NTSC project then VV will be applying pulldown during preview. Switch to a 24p project and it doesn't have to do that.
I think that is the most likely explanaition.
Alternatively what was the source of the footage?
Very few cameras can shoot real 24fps, despite seeming to have that option in their menu. PD150 is one culprit that comes to mind, even my D8 camera thinks it can shoot 25p, must try it one day to see just what I end up with.
DigitalOblivion wrote on 11/19/2003, 3:43 PM
It's 24p standard footage from a DVX100. Standard meaning it doesn't use the advanced pulldown. I didn't think choosing a 24p template would be necissary for 24p Standard footage...and what's the difference whether I choose the template or not..... as long as I have "remove pull-down in 24p footage"?
Chienworks wrote on 11/19/2003, 3:54 PM
What properties are listed for the clip in the media pool window? Does it say 24 or 29.97? It would seem from your description of what's happening that it must really be 24fps. If the clip's frame rate and the project frame rate don't match then the clip will have to be resampled. Resampling is a very intensive task and this will slow down the playback frame rate.

So, while it's not necessary (or even always desirable) to match the project frame rate to the source clips, it will cause a lot more work for the computer to do if they don't match.
farss wrote on 11/19/2003, 4:57 PM
If you have remove pulldown then you end up with exactly 24 fps which is not standard video. If you then put it into a standard NTSC project VV has to apply pulldown to get it into 29.97 or whatever fps which will involve a lot of processing.

Unless you are going out to film or a 24p DVD you shouldn't remove the pulldown.

Hope that helps.