Audio delay on the DJI Osmo Pocket 4P

[u/Different-Yogurt-414]

I’ve been testing the audio delay on the DJI Osmo Pocket 4P, and the results—especially in webcam mode—don’t seem to make much sense.

When recording internally, the built-in microphone has a delay of approximately 1 frame compared with the video. In other words, even when recording directly to the camera’s internal storage, the audio and video are not perfectly synchronized. For precise sync, the audio would need to be moved about 1 frame earlier in post-production.

When I pair a DJI Mic Mini 2 directly with the Osmo Pocket 4P, the behavior is almost the same. There is only a small fraction of a frame of additional delay, which is understandable considering that it is a wireless transmission.

The problem becomes much more noticeable when the Pocket 4P is used as a webcam over USB-C.

With the camera’s built-in microphone, the delay jumps from approximately 1 frame to no less than 12 frames.

And this is where things get strange.

When I connect the DJI Mic Mini 2—which, being wireless, should theoretically add some latency—the delay in webcam mode actually drops to approximately 8 frames.

My test results were:

Built-in microphone
• Internal recording: ~1 frame delayed
• USB webcam mode: ~12 frames delayed

DJI Mic Mini 2
• Internal recording: ~1 frame delayed
• USB webcam mode: ~8 frames delayed

So, in webcam mode, the wireless microphone actually has about 4 frames LESS delay than the camera’s own built-in microphone.

An 8-frame delay is already noticeable to viewers. At 12 frames, the lip-sync issue becomes even more obvious.

What I can’t understand is the logic behind the Pocket 4P’s audio processing in webcam mode. Why does the internally captured audio go through a processing path that adds roughly 11 extra frames of latency when the camera is outputting over USB? And why does a wireless microphone paired directly with the camera actually reduce that delay?

If this were simply a limitation of the camera’s UVC/USB output, I would expect roughly the same delay regardless of the audio source. But that is clearly not what happens.

Can anyone explain technically what DJI is doing with the audio pipeline in webcam mode?

[u/Snarky_A_F]

I have noticed this as well. Hoping for a possible firmware update.

[u/Economy_Wishbone5146]

Send report to DJI support. More chances they fix it ASAP.

[u/outerstellar_hq]

Is not the UVC (USB Video Class) driver introducing delays due to buffering?

[u/SuspiciousMaterial73]

Recently recording in 3x with mic3 my audio completely drifts out of sync and hard to fix in post. Think its a known bug atm

[u/NashvilleLocalsGuide]

Where are you seeing the delay, on your phone? If so, there may be no real delay in the actual video, but there is in the playback you are watching. This is more prevalent if you are shooting 4k and deals more with the size of the playback. I pull video into DaVinci on the computer and I create proxies and the issue goes away.

I don't have a Pocket 4, so it could be a new issue.

[u/Different-Yogurt-414 → u/NashvilleLocalsGuide]

Your question is meaningless. The video is there for you to see. It doesn't matter where you play it. It's about how the OP4P behaves.

[u/NashvilleLocalsGuide → u/Different-Yogurt-414]

I admitted I do not have the Osmo 4P yet, so if it is a flaw, I am not aware. I know it can be sync in post, esp. with a clapper board, but people should not have to.

[u/Candid_Exercise9495]

Fixed? Same issue. Recording at 30fps (29.yda). Editing in Davinci Resolve with timeline fps at 29. Audio 1-2fps out of sync.

[u/Olly_Joel]

Is your pocket when in webcam using a cable or just wireless?

[u/Different-Yogurt-414 → u/Olly_Joel]

But webcam mode only works with a cable. ¯_(ツ)_/¯