Slow motion video is jumpy and flashing at transitions

chewbonkay wrote on 12/2/2001, 4:39 PM
I recently upgraded to VV3 from VF2 and am experiencing some problems with slow motion video that I did not have in VF2. Whether I use velocity envelopes or just CNTRL-DRAG the clip, the .avi render of slow motion is very jumpy. I thought I solved this issue (after reading earlier posts) and selected resample of the slow motion parts. This does take care of the jumping but really slowed my render times.

Thus, my first question - Must I resample whenever I use slow motion? I never had to do this in VF2 and really hope I don't have to always do this in VV3. Could this have anything to do with the new codec?

Secondly, while the resample did solve the jumping something else appeared - flashing at transition points. (I also posted this as a reply under "Bad transitions in VV3" ) I have noticed that if I overlap clip B on clip A to form an auto cross-fade that just as the cross fade begins I get a 1 frame flash of clip B, followed by the proper cross fade between A and B. I'm using the NTSC DV specs. This did not occur in VF2 either. Again, all the video here is slow motion.

I am running P3-700 320RAM, 20GB OS drive and 80GB dedicated video drive (almost to capacity currently).

Thanks in advance for your assistance.

Comments

Rodeomonkey wrote on 12/2/2001, 10:20 PM
dear chewbonkay,
I did a lot of beta testing with VV3 and raised the same issues with sonic foundry(the situation is worse if you reverse your footage). I opperate in a PAL environment and have had other PAL problems with VV2 in the past, so i thought that this may be another PAL only problem, I'm sort of relieved and disapointed to find its not.
Sonic foundry sent me some detailed advice on fixing the problem, but stop short of saying its a CODEC problem, it improves the situation but dosen't fix it entirely.
Your on the right track with resampleing and yes it is the most effective way to solve the problem, long render times and all. For further improvements try shortening the interleaving intervals from the default of 0.250 second but again longer render times result. Changing the render field order may help and at worst you may need to render the original section of footage as progressive scan, then stretch it then re-render it and put it back in the time line(not a good option but sometimes the best compromise).
As for issue 2 (flashing at start of cross fade) i've had this problem with VV2 but not so far with VV3, try direct X 8.1 the VV2 thing was a windows problem on my machine ( i run win2000 on a machine nearly the same as yours).
Good luck,
jason