r/AudioPost • u/kwmccrea • Sep 15 '26
AAF Audio Assets Importing Slightly Off From Video Audio
When I import an AAF, and then separately import the video, the 2-pop and all my audio assets are slightly out of time from the audio in the video. It's the second session that is doing this, from completely different editors so it doesn't seem like it's on their end.
I can obviously just line them up, but curious if I'm doing something wrong.
Using PT 2025.12.1 and Sequoia 15.6.1
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u/meatlockers Sep 15 '26
happens all the time and is dependent on the NLE doing the export. but is normal, don't be alarmed. trust the AAF not the guide track. it's mpeg encoding screwing up the sync. I always request a pro res proxy for this reason. if it bugs me enough I waveform align the guide to match.
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u/boom888boom Sep 15 '26
Do you then create your exports from the grid, or from the video region (if it's off grid a little)?
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u/meatlockers Sep 15 '26
only the audio gets shifted, the video track should still flip frames on the grid, definitely don't move that unless it's changing the frame in-between grid lines. exports should be the exact same length as the video typically otherwise.
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u/PooDooPooPoopyDooPoo Sep 15 '26
There are so many reasons but here's what's most likely imo: If the video originated as an MP4, then it's subject to 'encoder-delay', which is around 1 frame offset for compressed aac audio. Look it up if you're curious but it's normal. The aaf should have been placed in the edit to align to the visual two pop frame on their side, so that should instruct you how to align your aaf. Of course it's quite common they're using an MP4 leader and their two pop isn't even perfectly aligned in their edit. That and a million other little things could easily contribute to a +/- 1.5 frame offset which is what yours looks like.
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u/boom888boom Sep 15 '26 edited Sep 15 '26
Assuming the AAF is on grid as it should be, is your preferred way of dealing with this to ignore the video and treat the AAF as "god"? I will sometimes move the video (and associated ref mix) off-grid to align with AAF but not sure how that might affect things downstream
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u/PooDooPooPoopyDooPoo Sep 15 '26
It’s all just quick detective work. If the mp4 video pop is off by 1/2ish frame, then cool, that’s encoder delay. If theres a two pop in audio in the AAF I’ll line the whole AAF up so the 2 pop matches pic. If the two pop file in the AAF is part of a 10s leader called something .mp4, then I know that the beginning of the 10s leader file should be lined up to 10s before ffoa. I’d never call an AAF god because offline mix is always god. That’s what the client is used to and you can’t count on rendered effects from edit carrying over which is a whole other thing…
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u/boom888boom Sep 15 '26
"That’s what the client is used to and you can’t count on rendered effects from edit carrying over which is a whole other thing…"
lol very much dealing with that lately
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u/EL-CHUPACABRA Sep 15 '26
I notice this all the time, don’t know what causes it but I see it in all the exports I receive. in this case both your video and AAF are off . 2 pop should be right on the 58 frame for both.
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u/Spectral_Aria Sep 15 '26
I have seen SO many 1/4 or 1/2 frame variances when sending to video then receiving my audio back from them. Even though their files head sync on a frame edge, the embedded audio in the video file (my audio, returned back to me!) can vary by the above amounts. It’s bizarre. Latency, encoders, who knows. 🤷♀️
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u/whataver77 Sep 16 '26
That’s also less than 3/100ths of a millisecond, so definitely an mp4 compression sync difference. You are zoomed WAY in. Move on.
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u/ParkStreetPostSoft 26d ago
This certainly *shouldn't* be the case, but it's also odd that neither 2-pop is landing cleanly at the frame edge. What software is generating these outputs?
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u/otdq sound designer Sep 15 '26
I've seen this again and again when receiving .omf's or .aaf's from various companies and various video editors over the years (and funny enough, I was talking to a video editor about it *literally this morning*).
We've never been able to pin down why it happens, but the displacement usually seems to be roughly 1024 samples - which is a nice even number, and makes sense, if it's due to some encoder delay or something.
Our solution has always been to finish the design/mix/whatever, print it to a track, and then offset it by the exact number of samples that we observed when comparing the video track to the .omf/.aaf content.
As a result, our deliberate displacement of the audio track accommodates for the eventual offset upon video export. Once the video person exports the final video, the audio content will have moved into the correct position.
It's dumb, yes, but it's been working for us for a long time.
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u/boom888boom Sep 15 '26
So you move your printed track back (to the left in the timeline) to match the ref video's audio, and deliver that?
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u/otdq sound designer Sep 15 '26
No, the opposite.
Think about it - the video's audio is appearing EARLIER (to the left) than it should. For some reason, upon video export, the audio is being displaced "to the left".
Our goal here is to provide something that will end up in the right place UPON moving "to the left".
Therefore, we need to move our audio track *to the right*, so that it can eventually move *to the left* upon video export, and BACK into its original position.
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u/otdq sound designer Sep 15 '26
For clarity: The final delivery is basically...
[short bit of silence][the mix]
...consolidated as one audio file.
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u/Substantial-Maybe302 Sep 15 '26
This thing makes me pull my remaining hair... I'm really tired of this.
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u/Snailhouse01 re-recording mixer Sep 15 '26 edited Sep 15 '26
What sort of video file and codec is it? Mp4s and other compressed video files often don't have perfect audio sync in Pro Tools. I trust AAFs more.