When mirroring from my iMac to my Apple TV 4K, the video and audio are out of sync, with the video leading the audio by a fraction of a second. Both devices are connected via Ethernet. I know that with normal audiovisual processing, the audio is delayed a bit, since the video processing takes longer., It's as if there is too much delay in this case. Is there any adjustment that can be made to fix this?
iMac 21.5″, macOS 11.2
There are no controls to make sync adjustments on device level.
AirPlay would take any delays into account, so that it arrives in sync on the viewing device.
I fear your source file may need adjustment. I take it that the file is not from iTunes Store or Apple TV+ origin? Possibly the video track and audio track do not start at the same time, causing sync issues with the tvOS player.
The file was live-streamed from the Met Opera to the iMac. I should have mentioned that the sync was fine on the iMac. It was only when mirrored to the Apple TV that the sync was wrong. The Apple TV also syncs just fine when it is accessing streams directly.
Audio and video out of sync when mirroring
