Audio Sync with Television Studio HD live streaming

Hi,

I am a newbie to the ATEM family and am running into an issue with audio and video being in sync when streaming live video. I am wondering if I am doing something wrong. Before you ask, here is my base configuration:

Audio:
Shotgun mic->XLR->Zoom F4 Recorder/Mixer->XLR->ATEM->SDI PGM Out->iMac

Video:
Panasonic G85->HDMI->Camera 1 in->SDI PGM Out ->iMac

Note that I have camera audio disabled and XLR audio enabled in the ATEM control panel. This would seem to be the cleanest configuration, but it does not work well...

Here is what I have tested:

1. Config Listed above -> Audio is out of sync
2. Turn on camera mic input and disable shotgun/F4-> Audio sounds bad (duh!), but is in sync
3. Connect Zoom F4 main out to camera Mic input and use the same camera wiring as above-> Audio is in sync (In this one, I disable XLR audio input on the ATEM and enable Camera Audio.)

Now I am trying to understand why the audio is so out of sync in #1. Clearly the audio is not being received out of sync since #3 works, and so it appears that the ATEM is adding some kind of delay. Is that correct? Is there something that I can do to fix this? I prefer to avoid going through the camera if I can, but that is an option if there is no alternative.

Thank you.

Your camera probably adds a delay to the video signal it outputs. If you feed the audio through the camera, the same delay will be added to the audio so it will be in sync with the video.

Your options:
- feed audio through camera
- get an audio delayer and connect it between the zoom and the atem in option 1
- use another camera with less or no delay on the video output.

The atem itself does not add more than at most one frame of delay, so the source of your problem is probably not the atem.

Use solution 3 in ur post.

As you are currently, the audio path and the video paths are taking different routes to their final destination.
Each has its own latency, delays etc. in getting to its destination. If you feed the audio into the camera the audio gets captured at the same time as the video frame and both get to where they need to be in sync.

Also ensure you fix the audio in the Atem to camera 1 (or which ever camera has the audio connection)
Don't use AFV as when the other cameras are active on program out you'll not have the audio feed.

Thank you both. I will do that.

The Zoom F4 can add delay to your XLR audio input to re-match.

Find out what your delay is and set the Zoom accordingly.

These testfiles might be helpful for that:
https://sync-one2.harkwood.co.uk/support/test-files

Cheers,

Daniel