Choppy video NOT slow motion

chewbonkay wrote on 4/5/2002, 7:30 PM
Has anyone else had this happen? I recently edited a 2 hours of footage into a 40 minute video. I used the trimmer to do almost all the editing. I trimmed and then re-assembled my video. Please note - as far as I can tell there were no dropped frames on capture.

Some clips needed color correcting, others did not. I applied a Broadcast clamp on the entire project via the preview window.

When I printed back to tape I noticed intermittent choppy video. Strangely enough, it seems to occur on parts that have NOT been altered in any way except trimming. The video just seems to be playing a tad slow (but audio synch is fine) and thus appears choppy. I have checked clip, track, and media properties and nothing has been changed. The source material looks fine.

I decided to render the entire project to an .avi and then print to tape. I still have choppiness, but in different places. The problem exists within the file itself as it is evident when viewing via Media Player.

Any ideas?! I don't think I've ever had this happen until yesterday! The only change on my system was the installation and uninstallation of Sound Forge 5.0 demo.

Please help.

Comments

Cheesehole wrote on 4/5/2002, 10:34 PM
can you isolate the problem by rendering a short shippet of video (a few seconds) that shows the problem consistently? if you can do that, maybe try rendering to DV but customize the template and turn off the audio. is it still choppy? is the resample switch on?
chewbonkay wrote on 4/6/2002, 5:54 AM
Cheesehole,

As always thanks much for your time. I realized after I posted that I had had this problem last weekend in a demo I put together but only on 1 clip. I checked the re-sample box on the clip properties and it did not help.

But I did notice something that I didn't notice before. The choppiness is apparent in the preview window within VV. Now as far as I can tell the clip and project are unaffected (I removed the project clamp) so there should be no reason for the clip to perform this way. Even stranger I opened the exact clip in the trimmer and the choppiness is gone! I then added the clip back to the timeline and as far as I can tell the choppiness is gone! I re-rendered both the original and replaced clip and there is a big difference.

If this is true (I may be posting in 12 hours saying I was completely wrong ;) ) then something clearly has altered the clip on the timeline...but that would explain the preview window - why would the render appear choppy as well, unless that is what VV 'thinks' my intention is?

Well, here's to hoping I haven't spoken too soon. I think I will simply re-place every clip in the project. Probably less time consuming then troubleshooting.

But if you (cheesehole) or anyone else has any more input I would obviously feel better knowing what the hell happened to these clips.

Thanks.
HPV wrote on 4/6/2002, 11:17 AM

Sounds like those clips flipped field order. I've had it happen here once. Check via clip Properties. NTSC DV should be lower field first.
SF, "as a work around" would making captured clips read only files protect them from this problem?
BTW, a few days ago I talked about this. On a side note, I passed on some info about reversing field order for negative velocity envelopes that I had read on a forum I'm no longer active in. Well, I tried it and it looked like crap. Sorry for throwing out bad info everyone.

Cheers,
Craig H.
chewbonkay wrote on 4/6/2002, 12:51 PM
I'll check that again. I acutally did look for field order as one of my first thoughts but everything seemed in order. Via trimmer, I re-placed all clips onto a new track and am in the process of a 10 hour re-render. I still have the "old" track so I will again check field order. I will post results of the re-render.

Thanks all,

Mike