Managing multiple audio sources in a video

porina · May 6

This is mainly about DJI Osmo Pocket 3 with external mic transmitter, but I guess could be treated generically as it can't be a new problem. I'm wondering what's the best way to ensure everything is in sync? Clapper board? If the offsets noted below are fixed I guess I only need to work it out once then manually apply it.

The camera itself has a built in 3 mic array that records a stereo track by default, but it does badly in the presence of wind with no easy physical solution to improve it.

I tried the wireless mic transmitter that came with it. This is a mono mic. When used, there is a baked version in the video file and the internal mic is not used. I can optionally save up to 32-bit backup file on the mic itself. If I drag this onto the video timeline with the same start point, it does not sync! The start of the mic file is not the exact same time as the video file. I think it is a small offset, but I've not looked in detail yet. I'd speculate they might not have counted the latency of the wireless link, but this is untested so far.

I just found a setting that allows the internal mic content to be saved at the same time. It looks like the wireless mic will still be baked in. I haven't tested this out yet, so I don't know if it also has a problem with sync or not. It looks like this setting was only added in a late January firmware update, and I bought this in December.

In case you're wondering, basically I have a problem with wind noise and the internal mic. Due to the mic port placement there's no great way for me to stick a dead cat around it. The external mic comes with a tiny dead cat and in testing so far it has significantly better wind noise resistance. But it is only mono sound. It also has the advantage it can store natively in 32-bit so should have better dynamic range for editing if needed. Basically I'll want to use the internal stereo mic if there isn't excessive wind noise. If there is, or any clipping problems, I'll fall back to the external mic.

TempestCatto · May 6

What software are you using? You should be able to see the spikes in the audio tracks. You'd want to use those spikes to line everything up. A hefty "clap sync" never did me wrong. But I hate editing to the point I don't do it anymore (and haven't for a couple years now).

Electronics Wizardy · May 6

What software are you using? In resolve, I can select all the clips and select sync and basically don't have to think any more about audio(really depends on the exact setup though).

Brian McKee · May 7

You should always have some visual cues in video to line up audio. Even with good software/hardware solutions, sometimes you have to line it up by hand.

porina · May 7

8 hours ago, TempestCatto said:

What software are you using? You should be able to see the spikes in the audio tracks. You'd want to use those spikes to line everything up. A hefty "clap sync" never did me wrong. But I hate editing to the point I don't do it anymore (and haven't for a couple years now).

Vegas 19. The displayed level of the 32-bit track is very low though so I cant really see anything. Presumably as it is full dynamic range without gain control. I did wonder if I should pre-process it externally before using it.

I try to avoid complex edits too, but recent video I took really needs it.

8 hours ago, Electronics Wizardy said:

What software are you using? In resolve, I can select all the clips and select sync and basically don't have to think any more about audio(really depends on the exact setup though).

Vegas 19. I'll have to look if there is a sync function built in. I did download free version of Resolve with a view to checking it out, but never got around to it. Guess I could give it another look as there are quite some shortcomings in Vegas.

Edit: in searching it does look like Vegas can do a sync using audio. I'll check if my specific version does it later.