After Effects Video Lag and Looping

[DiscoEdits]

Hello everyone! When I try to preview a video in After Effects (AE) I will press space, however once I press space, it previews 20 milliseconds of video and then will start looping. It will keep playing 0 - 20 milliseconds forever and won't advance. This is on a comp I have used for 2 weeks and I have never had this problem. Please look  at the attached video below to get a better understanding

what I am talking about. HELP!!!!

[Rick Gerard]

The first amateur mistake I see is that the comp is almost three minutes and forty-five seconds long. This tells me you are trying to edit a video in After Effects. AE is best suited to working on individual shots that need more manipulation than you can do in an NLE. My average comp is under 7 seconds. I worked on last week that was only about 10 frames.  If you want to put together a long video in After Effects put each shot or short sequence in a comp, then create a master comp and sequence your shorter comps to do the edits. The most efficient workflow on almost all AE projects is to do the editing in PPro, render your complex AE comps, and do the final assembly and polish in Premiere.

You do have the comp resolution set to 1/4, which is good. Setting it to Auto is usually more efficient.

When you get a really short preview you either have a cache that is completely full or the system is very low on resources. This would be pretty typical if your system only meets the minimum system requirements. AE will run on a system with only 4GB of ram, but you won't get any kind of preview performance.

The first thing I would do is use the Edit>Purge>All Memory and Disk Cache menu. If that doesn't help then Reboot, restart only AE and try again.

If you are still having problems please give us system details and a detailed description of the workflow.

[DiscoEdits]

Looks like that didn't work.

Processor: Intel Core i5-7200U CPU @ 2.50 GHz

Ram: 8gb

Graphics/GPU: Intel HD GRAPHICS 620

[Rick Gerard]

8 GB is the minimum. What is going on with the layers?. How much free space? Intel Graphics makes this sound like a laptop. Are you waiting for AE to cache the preview? Are you new to After Effects?

[DiscoEdits]

I've been with After Effects for a while. Since January. The layers are different video clips and effects. I am on a laptop. I'm not sure how to tell if I'm waiting. This has never happened before and i haven't changed any settings. The preview works perfectly fine on other comps.

[Rick Gerard · Accepted solution]

The first thing I would do is shorten the comp or just start over. It's insanely long for almost all projects. One-shot per comp should be your go-to workflow. AE should only be used to do things you can't do in an NLE and you should only work on frames that will end up in the final edit.

Different video clips and effects does not tell me anything about the load on your system. A single layer with a particle system that is generating hundreds of thousands of particles can bring a powerful system to its knees. Temporal effects can also eat up a lot of system resources. Just warp stabilizing a 20-second shot can easily completely overwhelm a minimal system. There are workarounds, like immediately rendering a warp stabilized shot and getting rid of the warp stabilized layer, but we need details to help you out.

You could also just have a glitch in the source video. When you run into problems like this the best troubleshooting approach is to press the U key twice to look at all modified properties of all layers, start soloing layers until you figure out which layer is causing the problem, then resetting things until the problem goes away. It usually does not take very long to figure out where the problem is coming from. Once you know that you can usually figure out a work around.

[Martin_Ritter]

Some other tipps:

- click on the info-panel (next to the preview panel we see in the video), it shows you if AE is currently rendering or if preview is slower than realtime

- in the preview panel, click on "Cache Before Playback". Hit spacebar and set it render, could take a while.

*Martin

[DiscoEdits]

Yep, was a glitch in the source video. Deleted it and it made the whole comp better. Thank you so much for your help!