-
Judder / choppy playback
I hope someone here can help us with this. We are working since almost a year on this project, all done in AE, and some comps are playing back choppy/juddery no matter what I do. In any output format, on Mac and PC with different setups, on media players and so on…
The very strange part is that it’s not persistent, sometimes it’s there and sometimes the playback is fluid, with the same file!Here’s the workflow:
– Captured footage from tape DV/NTSC, 29.97, NDF
– De interlaced using FieldsKit
– Pre rendered as ProRes422HQ
– Dropped several of those footages(up to 20) in a HD/HDTV-720 @ 29.97 Preset Comp
– Parented all to a null with a slight wiggle expression to simulate camera movement
– Final render as ProRes422HQ or Animation codec
– Compressed for distribution to H264, MP4, WMV9 and even downscaled to DV, the judder comes and goesWorkstation:
– MacPro 2.66GHz Dual, 3GB RAM
– OS X 10.5.4
– AE 8.0.2
– QT 7.5.5 (I guess when we started this project it was 7.3)
– Playback in FCP, QT Player and VLCHere’s an example of a sequence (H264 / 720×1280 @ 29.97 – 40Mb):
https://rapidshare.com/files/144622881/Bridge.zip.htmlI would be very grateful for any input on this!
-
1 Reply
-
Thank you very much for your answer Dave!
Some answers to your suggestions :
– We shot the images using the Sony PD-150 DV Camera, which was set to NDF (since the time of the final project was not an issue). Obviously shooting at 29.97, so I guess we can exclude problems from there.
The tapes were captured using FCP, and they play back fine on the computer and on a control monitor.– Since the cam does not shoot in progressive mode, and we scaled and rotated the footage, it seemed necessary to de interlace. This was done in AE, using FieldsKit. (The pre-renders play back fine as well)
– The HD Comp is composed with several SD videos, so there was no up-scaling involved. It was actually a down-scaling, so no concerns about image degradation this time.
– Problems with the ProRes codec, that’s what I thought as well at a time. So we pre-rendered our footage using the Animation codec….. same result.
– I start to blame QT as well, but since the project was rendered in all versions since 7.3 maybe the problem lies elswhere.
Two month ago we had a company do a presentation at a event. They use PCs for HD pojections, in the beginning all went fine, and after a couple hours of looping it started to be very choppy and skipped frames. Restart the machines, reset the beamer, let all cool down…The guys worked all night to find the cause, without any luck.
I have never seen something like that in all those years doing video! If the problem would occur every time and on the exact same spot, I’d blame my motion paths or something else, but it comes and goes, on different playback systems!If you get a chance, take a look at the video I uploaded, maybe you’ll see something I don’t…
Reply to this Discussion! Login or Sign Up