After Effects 7.0 audio out of sync with video

[Jim Zito]

Hey. I noticed that too. I often have the same problem. It’s pretty annoying. Sometimes when I RAM preview, the audio cuts out before the end too. I usually just end up shutting AE down and reopening it.

[Gino Guarnere]

Well, as an AE novice, I gotta say I’m not happy yet. For a start, why the heck can’t I just drop a clip into a Comp and watch it at the proper frame rate? Is this a RAM “thing?” (I have 2 gigs, and FCP plays clips in real time as soon as you drop them on the timeline…)

Is this the world of AE? Someone please tell me how great this program is once again…

Thanks!

[Andrew Kramer]

Do you have a decent Video Card. Set to always use Open GL and you should get realtime.

[John Davidson]

Funny, I almost made a post saying the same thing a few weeks ago, but I’m not an expert here so I let it slide.

I have noticed a significant lag in video with heavily complex comps. What appears to be happening is that RAM preview does not play at realtime when processing effects. The audio, however, does play at realtime, so the only way I can sync the two is to reduce the quality to around 50%, which seems to alleviate the issue.

I really don’t remember this ever happening on 6.5. RAM preview is built to play back a small section at real time – so once the green bar goes through the comp, even at high quality, why isn’t it playing back at real time?

I am running a dual 2.7, 10.4.5, 8 Gigs of ram, Kona 2 latest drivers, with 10 and 8bit uncompressed footage.

I have an ATI 9650, so my OpenGL is limited (THANKS APPLE!). I bet motion blur and anti-aliasing are sweet with OpenGL!

-neo

[Gino Guarnere]

Well, I have a G5 Dual 2.5, 2 gigs of RAM and the Nvidia Ultra 6800 DDL, which is one of the beefier cards for the Mac (and the PC, for that matter). I’m also tied into the AJA Kona LH for the purpose of monitoring my clips on my NTSC monitor, so I am using some of the Konal presets for the “output” of my video.

Comps are set to HDV 1440×1080 in 16:9, but for some reason, if I just drop a clip in and let it play, it’s a bunch of time doing a RAM preview (don’t even try to hit the space bar). I guess I’m just used to Final Cut, where you drag a clip to the timeline, hit the space bar, and get a real time preview of the clip. It’s really a showstopper to drop a clip in and have to wait to watch the clip in its original format before even applying any changes to the clip in AE.

Any other suggestions would be helpful. I should also clarify that I’m not questioning the supremacy of AE, as I realize there are a lot of folks here who use AE as part of their daily bread, but of course I’m responding to the fact that I’m being asked to make a change, which is always difficult.

Thanks again, all. I look forward to getting through this “warmup” period and hopefully contributing something back to everyone in the form of some knowledge along the way.

WB

[Steve Roberts]

Well …

1. AE will never play anything the way an NLE does. An NLE will only immediately play clips that match the sequence they’re in, and then only if the hard drive and/or hardware codec can handle it. AE can play any clips in the timeline as long as your system has the relevant codecs installed. The price for that flexibility is rendering time.

Imagine dropping a clip into your NLE sequence that doesn’t match the sequence settings — you’ll have to wait for it to render. That’s AE, but it does it all the time. It’s not an editor, it’s a compositor and motion graphics app. Everything has to render in AE — that’s why AE is impractical if you’re not doing anything to your clips. All compositors have to render — it’s just that the “big iron” million-dollar machines do it faster.

AE uses RAM preview as a way to speed up the rendering time when you’ve only changed part of your comp. It renders frames, stores them in RAM, then plays back from RAM at the comp’s frame rate, or half that if you ask for it. If you change part of the comp, AE keeps the unchanged parts in RAM, re-renders the changed bits, then plays as before.
(note: you still need to edit>purge>image caches from time to time)

2. I haven’t used OpenGL in the past dues to its limitations, but it does a different kind of rendering, using the hardware on the graphics card. It may give you the quick feedback that you need, but beware — it has its limitations, so there are probably a lot of effects that can’t be rendered through OpenGL. There should be more details in the docs.

At any rate, you should know that NLEs are better at some things, compositors are better at others. One does not replace the other.

Does that help?

[Gino Guarnere]

Steve,

It’s like the clouds parted 🙂

Thanks for making the distinction. Although I was aware the AE is not a NLE, I guess I needed to hear what it IS there to do, which largely answers my next questions around what I’m actually going to do with it 🙂

Thanks, gents!

G

[John Davidson]

I don’t think that really answers the question of why RAM preview plays back video slower than audio. As you said, the video is stored in RAM once it’s rendered, and then (theoretically) played back at the frame rate designated by the comp. What I’m saying is that RAM preview doesn’t play back at the correct frame rate when dealing with a complex comp.

This was not an issue in 6.5. Without an accurate way to preview a segment of a comp at full quality, AE loses a good deal of it’s effectiveness. The majority of my graphics are tied to music and sound.

It really feels like a bug, IMHO. I bet 7.1 fixes it.

-neo

[Steve Roberts]

You’re right — we sort of had two threads in one, so your question didn’t get answered, by my post at least.
You’re also right — I too never saw that behaviour in 6.5.

Sorry, wish I could be more helpful. Haven’t upgraded yet.

Steve

[Gino Guarnere]

Hey all,

Any updates on this issue? I really can’t use After Effects 7.0 with music when the comp gets too busy. The music just plays in real time and the comp lags way behind it in RAM preview. I’ve turned all the preview settings way down, I’m running 4 gigs of RAM on a Dual 2.5 gig G5 with Open GL turned on as well as turned off.

What’s the deal? This is killin’ my ability to sync audio to my motion in AE, which sort of renders AE useless for music once the going gets tough.

Anyone, Adobe, somebody please advise!

WB