Adobe After Effects cc 2017 - Audio slows down and then speeds up at random

[_makeus_]

So i just got after effects cc 2017 and it seems that everytime i try to preview my footage. the audio will slow down and speed up at random times,

the footage seems to work out fine but its just the audio its really annoying because im just trying to edit my stuff.

[Mike_Abbott]

Does this help?

Preferences > Previews > Mute audio when preview is not realtime

[_makeus_]

no sadly, that just makes the audio cut out and play again at random

[P.M.B · Accepted solution]

The problem is that your footage is not playing back in real time.  Once the footage is cached & playing in real time your audio will be fine.  Assuming you have adequate RAM to use AE with any efficiency you may also need to purge your cache.  If that doesn't work and your footage is just very system intensive then you might have to temporarily drop your preview resolution down to a half or third or quarter.  The behavior your describing is normal.  At least in every version of AE "post 2014". 

[Rick Gerard]

Sounds like you are new to Visual Effects and AE. You need to study up on how the UI works and what to expect from the program. AE is not a NLE, was never intended for editing, and us useful only for doing things to shots and short sequences that you cannot do in a NLE. That's it. Please study up and you'll relieve a lot of your frustration. Basic AE

[descalabro]

I have the exact same issue as the OP and, guess what, I'm not editing anything, I don't even have any file in the project other than the WAV file. It slows down even when I merely maximize or collapse the layer view. I've got 16GB RAM, 10 of which are for AE, and i'm not running any other software. I've set all the preview resolution options to 1/4, I've checked the "Cache Before Playback" box, and it keeps doing it after caching, I've tried a 6 second WAV file with a 48 kHz sample rate to match the audio hardware configuration. The problem persists. As far as I know, AE isn't intended only to add effects to shots, it's widely used to do animation too. And while animation does not necessarily require video editing, it does often require synchronization with sound, so I don't think it's fair to tell people to "study up" as if they're doing something wrong when all they are trying to do is simply preview audio in real time. The audio is going in all kinds of crazy speeds, and it only happens in the preview.

Besides, there are countless reports of audio problems in AE on the internet, and anyone who's used other softwares can tell this AE behavior is abnormal.

[descalabro]

No, that's not the problem. These are slow downs and speed ups that happen regardless of the amount of material you've got in the timeline. To me, it happens even when the only thing I have in my project is the audio file, with all resolutions set to 1/4. People who haven't dealt with this issue will dismiss it as "normal and justifiable AE behavior". But it's not. There is something going terribly bad with the way AE plays audio in preview.

[RopeChoker]

Gutter-Fish is telling you right. Same thing happened to me and I had to drop my Preview res down to 1/4 until I got things better organized. Like I had multiple clips in my project without any In/Out points set. Once I got those points set, I could increase my Preview res back up to 50%

[Claire_a_bradshaw]

I'm finding this issue with CC2019. My system is a Core i7 Xeon 20 core CPU, 128gb RAM and a 24gb Nvidia card. My colleague and I putting together clips in AE for use in PP. I'm finding that when I do a RAM preview, even with just an HD 1920 clip playing with speech audio - ie no effects that have to be rendered on the fly - it still slows to a crawl and the audio sounds worse than Sylvester Stallone after 14 pints of beer. 

Now if AE was processing a ton of effects at once, even with 128GB, I would understand the slow down, but this is just an mp4 slotted in over a voice over playing at 1/4

So is it because I'm doing things wrong with compositions? The more layers in compositions, the quicker it ram previews?

thanks

[antonym13860236]

They never fix anything in that obsolete software. Whenever y to do anything in AE people will start to say AE was not built for this and that ...  

If I Import a footage it will lag, if I work motion graphics and rasterize it will lag... meanwhile unreal engine, blender and  this community is having realtime renders with insane optimisation and graphics, while im stuck  here to try to preview a 16kbps mp3 file on AE.

We need another software to work on. What a trashy software...

[zandwacht]

I may have found the solution. I was rendering a cached comp (so playback in real-time) and audio kept sounding slowed down. It's an 48Khz 24bit stereo track in a 48Khz project. The problem was the comps framerate of 29,97 drop frame. When I switched it to 25fps, the track sounds perfect. When I switch back and fourth between framerates, I can toggle the problem on and off 🙂 

--> I think AE has a bug where it samples the audio files incorrectly with certain combinations of frame rates and audio sampling frequencies.

[1980Hanley]

Seems we are getting somewhere, nice one Zandwacht!   Thanks.

First time it's happened to me where a whole mp3 track has imported at the wrong speed.  I had to lower my compostion frame rate to 15 fps for it to play correctly

Does seem like a bug.

[ramazant30540788]

This has definitely been my only solution! thanks

[SpaceCorn]

I've got this figured out on my system after no luck with any of the suggestions in this thread including the so called previous SOLVED solution with no luck there either. The problem is the Audio Sample Rate in Project Settings under the File menu. The default is 48.000 khz which is too high for real time playback and rarely needed for most projects anyway. Change this to 44.100 which is still a very high quality and that fixed it for me instantly. Also keep in mind that if you move your mouse while playing back, that can also cause the audio to slow down, so change your sample rate and get your hands off your mouse after pressing play and you should be good for perfect playback as long as you first buffered the section of your timeline you want to hear in realtime. The problem is not your hardware, and contrary to what some believe, After Effects is 100% meant for realtime playback for any length of timeline that your system is able to buffer. If you can buffer it, it should play in realtime with no lag. The max buffer time is dependent on your hardware and available cache space. Hope this helps.  

[SpaceCorn]

In addition to changing your sample rate you'll still need to Edit > Purge and clear your memory cache often. These steps were not neccesary with previous versions but they are now. Until Adobe fixes this, these steps are working for me. Good luck.

[SpaceCorn]

This is going to seem too easy but first thing first, try restarting your computer first before any of the other suggestions. This very simple thing can solve it for some.

[1980Hanley]

I thik this was my issue actually as i leave my laptop on a lot.   Been fine since.  Thanks Spacecorn.