Multiclip jittery on playback at DVinfo.net

Carlos San Roman · May 4th, 2011, 06:49 PM

Here's a problem I've never had before. Editing a multiclip sequence and the playback is real jittery especially on the pans. I thought maybe it was on the original footage but the tapes are clean. Then I checked the individual captured footage and it too plays smoothly. The problem seems to occur only when I'm editing the multiclip in the timeline. I also was getting the drop frame alert every time I set the sync to open and played it in the timeline. The footage was shot in 60i and I rarely get that alert in that format.

Any suggestions are appreciated.

Thanks in advance,

Carlos

Bart Walczak · May 5th, 2011, 03:00 AM

Two reasons come to my mind immediately:

1. Lack of processor power. If you are trying to play simultaneously 4 streams of AVCHD footage, you need some serious CPU power to decode it. Dropped frames might be result of your computer not being able to keep up with decoding. Check your System Activity to see if you get 100% CPU usage on each core. In such case, you can convert the files to less CPU-intensive codec and see if it helps.

2. Lack of HDD throughput. If your files are uncompressed or transcoded to something that takes a lot of space, then your HDD might simply not be able to read enough information per second due to limitations of disk itself or interface (especially with external disks connected via Firewire or USB). Consider using some kind of internal or external RAID solution (preferably RAID 0, since it is the fastest) to widen the throughput, this should help.

Carlos San Roman · May 5th, 2011, 11:33 PM

Thanks Bart,

I actually have a pretty speedy Mac Pro with Raid. Turns out this was one of those gremlins that fixed itself by dumb luck. Don't ask me why but if I double clicked the Multiclip in the browser and played a few seconds of it in the viewer... It fixed the problem in the timeline. Like I said, don't ask me why but it worked every time I had that problem which only happened 3 or 4 more times, then it just disappeared. Go figure???

Carlos

May 4th, 2011, 06:49 PM	#1
Carlos San Roman Regular Crew Join Date: Jun 2006 Location: Orange, CA Posts: 46	Multiclip jittery on playback Here's a problem I've never had before. Editing a multiclip sequence and the playback is real jittery especially on the pans. I thought maybe it was on the original footage but the tapes are clean. Then I checked the individual captured footage and it too plays smoothly. The problem seems to occur only when I'm editing the multiclip in the timeline. I also was getting the drop frame alert every time I set the sync to open and played it in the timeline. The footage was shot in 60i and I rarely get that alert in that format. Any suggestions are appreciated. Thanks in advance, Carlos

May 5th, 2011, 03:00 AM	#2
Bart Walczak Major Player Join Date: Apr 2006 Location: Warsaw/Poland Posts: 716	Re: Multiclip jittery on playback Two reasons come to my mind immediately: 1. Lack of processor power. If you are trying to play simultaneously 4 streams of AVCHD footage, you need some serious CPU power to decode it. Dropped frames might be result of your computer not being able to keep up with decoding. Check your System Activity to see if you get 100% CPU usage on each core. In such case, you can convert the files to less CPU-intensive codec and see if it helps. 2. Lack of HDD throughput. If your files are uncompressed or transcoded to something that takes a lot of space, then your HDD might simply not be able to read enough information per second due to limitations of disk itself or interface (especially with external disks connected via Firewire or USB). Consider using some kind of internal or external RAID solution (preferably RAID 0, since it is the fastest) to widen the throughput, this should help. __________________ Creative Impatience - The Solace of Simple Solutions. A few useful plugins for Adobe users, and my remarks on the tools and the craft in general.

May 5th, 2011, 11:33 PM	#3
Carlos San Roman Regular Crew Join Date: Jun 2006 Location: Orange, CA Posts: 46	Re: Multiclip jittery on playback Thanks Bart, I actually have a pretty speedy Mac Pro with Raid. Turns out this was one of those gremlins that fixed itself by dumb luck. Don't ask me why but if I double clicked the Multiclip in the browser and played a few seconds of it in the viewer... It fixed the problem in the timeline. Like I said, don't ask me why but it worked every time I had that problem which only happened 3 or 4 more times, then it just disappeared. Go figure??? Carlos