Variable Speed Render Issue
by Ged Yeates
on
Oct 30, 2009 at 12:10:15 pm
Hello
I’ve recently updated to FCP 7.01 and have begun to encounter an issue when working with variable speed segments. When I add an ease curve to a speed segment it looks okay during playback with the green ‘preview’ bar over the clip but once rendered the resulting video is unusable as the speed change curve has what looks like a very visible jump on the speed change. It almost looks like the field order has been reversed!
I was wondering if anyone else had encountered this issue and maybe had a suggestion for curing it?
The un-rendered clip with the speed changes does perform as I want with the ease in/ease out curves but lacks the quality of rendered video but alas the rendered quality with ease curves just will not work smoothly. If I remove the ease curves and use linear it works perfectly when rendered but of course the speed changes are abrupt and not what I wanted.
I’m using the ProRes422(HQ) codec in PAL 16:9 capturing from Digital Betacam and an AJA ‘ioHD’ unit but the problem is also evident when I’ve replayed through a Matrox MXO unit. It does appear to be an interlace field problem as the canvas window in Final Cut pro shows the speed change looking fine but the interlace video monitor reveals the problem.
Re: Variable Speed Render Issue by Ged Yeates on Oct 30, 2009 at 1:03:45 pm
Hello
I've taken a critical look at the problem I'm encountering when rendering variable speed segments with 'ease' curves and it is definitely the field order that is being reversed which is the cause of the visual jump at the end of a speed ramp.
As I mentioned this does not seem to occur on 'linear' speed ramps just those with an 'ease' curve and only when rendered.
Re: Variable Speed Render Issue by Ged Yeates on Oct 30, 2009 at 4:08:02 pm
Hello
I just saw a newly released update for Final Cut pro 7 a rather small file of 1.8MB released today 30 October 2009 but it has not resolved the issue of field tearing on interlaced video when speed changes with ease curves are rendered. I really thought it was my lucky day but it was not to be.
It does seem to be related to the 7.01 update as I checked a couple of speed ramps with ease curves I rendered in version 7.0 and they look fine.
