Audio weirdness with long h.264 & h.265 exports

[JonRichardson]

Hello Premiere pals! For the past couple of months, I've been having an issue exporting long files (over 45 minutes) as h.264 or h.265. The audio starts off fine, but gradually shifts out of sync until there is just no audio at all eventually. I've switched versions to no avail and also used Media Encoder. The problem fixes itself if I bring the file into handbrake and save it as a new h.264 file there.

Any ideas? I'm the Media Producer at a Museum and often have to edit lectures. Thanks!

[Jeff Bellune]

Is your source video variable frame rate? If you don't know for sure, use the free MediaInfo tool to inspect the file. 

The fact that running it through Handbrake fixes the issue indicates you are using VFR footage, because Handbrake is the standard fix for VFR footage that misbehaves in Pr.

If you must use VFR footage in future projects, you'll need to allow time to process the source video in Handbrake.

[JonRichardson]

Thanks for the reply, Jeff. No - they're not VFR. MediaInfo confirms constant frame rates. The long exports were working just fine until they suddenly weren't.

[Jeff Bellune]

What software are you using to play back the exported video from Pr that gives you out of sync audio?

[JonRichardson]

Quicktime. VLC plays it back fine.

[Jeff Bellune]

So the exported file is just fine; only QuickTime doesn't like it.

How are you going to deliver these videos?

[JonRichardson]

They are kept for archival purposes and usually uploaded to YouTube or other sharing platforms.

[Jeff Bellune]

Do the videos play correctly once uploaded to YT?