Regularly-timed camera blackouts: HDMI sync issue
Posted: Mon Jan 17, 2022 7:07 pmDuring a live stream I had periodic blackouts in one camera connected to my ATEM Mini Pro. Never had this problem with this camera and cable before. It's a Panasonic camcorder running at 1080p/60 fps.
Today I hooked it up to the ATEM and used a stopwatch to time the on/off periods. Interesting artifact: the ON periods were always about 55 seconds, though off periods varied. When it's ON, the picture image is fine. During OFF periods, the audio meters for this camera still register signal (on the ATEM multi view screen).
When I connect the camera to an HDMI monitor it had the same issue, although the OFF periods tended to be about 55 seconds as well (not consistently). To me, this indicates some kind of drift between the sending frame clock and the receiving clock.
Conclusion: either the camera HDMI out or the cable is defective. (I don't have another Mini-HDMI cable at the moment, it's on its way).
My question is: what is the equivalent of "house sync" (or "word clock") in an HDMI system like ATEM? Is one of the HDMI lines dedicated to timing so that if that HDMI contact is dirty or wire broken, it drifts on its own? What unit is the master and which is the slave, or do they all just go into a digital buffer and get reclocked so they can be switched?
Thanks for any enlightenment the community can offer.
Today I hooked it up to the ATEM and used a stopwatch to time the on/off periods. Interesting artifact: the ON periods were always about 55 seconds, though off periods varied. When it's ON, the picture image is fine. During OFF periods, the audio meters for this camera still register signal (on the ATEM multi view screen).
When I connect the camera to an HDMI monitor it had the same issue, although the OFF periods tended to be about 55 seconds as well (not consistently). To me, this indicates some kind of drift between the sending frame clock and the receiving clock.
Conclusion: either the camera HDMI out or the cable is defective. (I don't have another Mini-HDMI cable at the moment, it's on its way).
My question is: what is the equivalent of "house sync" (or "word clock") in an HDMI system like ATEM? Is one of the HDMI lines dedicated to timing so that if that HDMI contact is dirty or wire broken, it drifts on its own? What unit is the master and which is the slave, or do they all just go into a digital buffer and get reclocked so they can be switched?
Thanks for any enlightenment the community can offer.