I've recently started dabbing into CS6 AE again and ran across an issue. I have some 1080p videos that I've edited and exported, but it appears that they always have audio issues. The video will start in-sync, but the father along it gets the more out of sync it becomes. Issue only appears with 1080 renders and not with 720p. Changing video bitrate, (tested from 8 to 30Mbps) and audio Khz haven't worked. Exporting the video as a .mov, .avi, .mp4, etc, all show the issue before and after encoding it using Media Encoder.
However, on a hunch, I decided to put the video through Windows Movie Maker, choosing different bitrates for video/audio. Every one that was rendered in WMM came out without the issue. Not sure if that indicates some sort of settings issue in AE when it renders.
Both the original and new video are 29.97FPS, and the audio for both is at 48 kHz. I see that the bitrate for the original audio is at 221kbps, but I don't see an option for that in AE. I tried changing it around a little (default at 128 kbps, tried higher and lower) and when I do the delay becomes worse. I'm currently seeing what happens when the FPS is changed.
So, I found out the issue isn't when it renders. Instead, it's from the get-go. When I import it into After Effects, the audio is delayed. When I looked into a little more, some suggestions came up saying it could be because of a variable frame rate, and to download HandBrake, run the file through there and then into After Effects, which fixed it for some people.
Unfortunately, I tried that and both the original file and the one from HandBrake have the same issue (both are .mp4). Upon importing, the audio is delayed. But again, only happens for 1080p, which I find strange. Quickest fix would probably import the audio and move it around so that it matches the video, but I'd like to figure out the problem and what the cause is.