View Full Version : Preview Movie Runs out of synch

01 January 2002, 05:04 AM
Hey all,
This forum looks like it'll be really useful. You've got catagories for just about every digital program worth using.

I guess if you've used After Effects you'd know about how it seems to never play the preview movie properly the first time around. Maybe it'll play it normally for the first two seconds but then suddenly it'll jump a few dozen frames and play the visuals around four seconds ahead of the sound.

You have to wait for it to replay the movie a second or third time before it plays it properly. Does anyone know how to deal with this problem?

01 January 2002, 04:53 AM
I'm using AE 5.0 on the Mac platform. I've been with AE since it was 3.0 and I've never had trouble with the RAM preview. Maybe some quirks with the new way it displays when scrolling. Sounds like maybe your suffering from a bad install, damaged preference, or possibly even video card issues.

01 January 2002, 06:21 AM
Hey, thanks for the response ;-)

I'm using After-Effects on a PC at the moment and I haven't seen how it runs on a Mac, but I expect all Adobe Software would run better on Mac OS, since it's a system built mainly for graphics.

One thing I've noticed when this RAM Preview problem is occuring is that there's the message "(NOT realtime)" printed in red at the bottom of the play control panel. Have you ever seen this message appear on your Mac?

01 January 2002, 06:25 AM
How much RAM do you have? I see 'Not Realtime' when its used up all the ram it can to produce a RAM preview of the sequence.

01 January 2002, 06:40 AM
I've got 512Mb of SDRAM. I have Mem Turbo II running the background as I'm working and this "(Not realtime)" message appears when MT II reads around 150Mb, not when it reaches zero.

This error only occurs in long previews, too. The longest preview I've watched without this happening has been maybe 5 seconds.
I use AE to build animatics, so it's consists of mainly still images.

01 January 2002, 09:07 AM
When all else fails ask the experts at Adobe. Heres their forum

when you find out please let us know :)

01 January 2002, 11:22 AM
Perhaps I am missunderstanding you, but it sounds like you might not be creating your preview right.
How are you generating your preview? Are you pressing play in the preview window? If so this does not technically produce a Ram preview. It will play your frames as fast as AE can, which isn't very fast.... to the tune of a couple of frames per second. A true RAM preview is achieved by pressing the "0" key on the keypad or going to the COMPOSITION menu Preview....RAM Preview. This will play you a realtime preview.
The movie loops based on the amount of ram you have.

01 January 2002, 12:11 PM
"The movie loops based on the amount of ram you have."

No, I'm definitely picking the Composition / RAM Preview option. It shows a small grey progress bar in the Comp Window (where the preview is seen) for a brief moment to prepare the render, and then a red progress bar creeps below the work area start / end selection bar at the top of the Time Layout window. Then the RAM Preview starts.

On really short previews of about three seconds, it's shows 30fps (realtime) in black text at the bottom of the time controls bar, which runs fine. But on the long ones, "(NOT Realtime)" appears there in red text, and the preview is skipping frames, stopping, playing too fast and generally being out of sync with the sound.

On discovering that, I've tried running a RAM preview and watching my Mem Turbo II counter as it's being rendered. On the longer previews, the counter does get to zero (my apologies - I said it doesn't earlier in this thread) and when the preview is finally rendered it's always out of sync. But if it hit the pause button on the time controls just before the memory counter reaches 20Mb or so, the preview will play fine.

So I guess the answer to my question is that the RAM preview will be out of sync if allowed to continue rendering when the memory has run out, just like you said, Sigma.

Yeah, I know - a little common sense would've saved us all some trouble ;-) but it can be said having a memory manager running visibly in the background is useful when using AE.

Thanks for your help on this, guys!

02 February 2002, 04:09 PM
There is a setting in the prefs for sound previews (might be an option in there). Also make sure that your comp frame rate and you footage frame rate are the same or your synch will drift.


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