Video on DJI Goggles, Audio in Your Headphones

When you cast video to a DLNA receiver, usually the audio travels with it and plays on the same device. With DJI Goggles that means the built-in speakers. GogglePlayer can split the two: the picture goes to the goggles as usual and the sound plays on the PC, through whatever output Windows has. Wired headphones, a USB DAC, Bluetooth earbuds.

This guide assumes streaming already works. If not, start with How to Watch Movies on DJI Goggles.

Select the Local output

Below the player there are two audio output cards. Stream sends the sound to the goggles. Local keeps it on the PC. Select Local, then pick the output device in the dropdown under it.

System default follows whatever Windows is set to, so if you switch devices in Windows during a film the sound follows. Or pick a device by name. For a file this is the only setup needed. Press Play and the picture goes to the goggles while the sound plays in the headphones.

Keeping it in sync

The goggles report their playback position to the PC while a file plays, and GogglePlayer uses that to lock the local audio to the video. Auto-sync runs the whole time. If the picture and sound drift apart, the audio is pulled back into place on its own. How this works in detail is covered in Syncing audio to a clock that ticks once a second.

What auto-sync cannot know is the fixed delay of your own gear. Bluetooth headphones add some, and the goggles' display adds some. That is what the A/V OFFSET control on the Local card is for.

Go by what you see and hear:

• Mouths move before you hear the speech: press −50.
• You hear the speech before mouths move: press +50.

Each press moves the audio by 50 ms. The comma and period keys do the same. For larger steps, hold Shift and press comma or period to move 500 ms at a time. Hold Ctrl and press comma or period for 10 ms. The scroll wheel over the value moves 10 ms, or 100 ms with Shift, and clicking the value lets you type one in.

The offset is saved between sessions. It describes your hardware, not the file, so once it is set for a pair of headphones it stays. If the audio slips for a moment and does not recover on its own, the R key resyncs it to the current frame without changing the saved offset.

Screen, webcam and capture card

The Local output also works when streaming a screen, a webcam or a capture card from the Capture tab. The setup differs in two ways.

Headphone delay. The goggles show the screen about three seconds after it happens, because of a buffer inside the goggles. GogglePlayer plays the headphones a delayed copy of the audio so the sound matches the delayed picture. The Headphone delay control on the Capture card sets that delay. The default is 3.0 s. Increase it if you hear things before you see them, decrease it if the sound lags. The right value can differ from one pair of goggles to another.

The headphones cannot be the Windows default output. For screen streaming the app captures the sound Windows is playing on the default output. If the headphones are the default, the delayed copy would play into the same capture and echo. Set the speakers as the default output in Windows, then pick the headphones by name in the Local dropdown, as in the screenshot. The app tells you on the Capture card if the selected output is still the default, and starts the delayed audio as soon as it is not.

The Mute audio checkbox on a screen source turns the audio off altogether, for when the sound is not wanted.