Using Fullscreen Projector while recording causes interruption.

Billv4875

New Member
We use a wireless HDMI transmitter to send our signal to monitors, and we record on OBS we experience intermittent signal interruptions. Approximately around the 20 minute mark, the laptop screen goes black for about .5 second, the picture comes back, then after about another second it "flickers" black and comes back on again. A second later, the monitors all go black and have to "recycle" as they locate the HDMI signal. When they are back online, about 12-15 seconds, we send the signal to the Fullscreen projector and we're good. It often repeats the cycle but not always. Recording is not affected except for a momentary freeze that appears to reflect the initial .5 second "blip". This only occurs when we record, just having everything live there are no interruptions. Any suggestions appreciated.
 

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konsolenritter

Active Member
Your scenario is not clear. Please try to describe more in detail, what is connected to what. And what shows the laptop main screen. Where is the transmission connected to? How is windows configured regarding the screens? What signal exactly goes fullscreen projector?

Aside from that, you tell about a 20 min thing. That sounds like a standard windows power save setting regarding "send display to sleep after 20min". May it correlate to something like this?
 

Billv4875

New Member
We have a Wireless HDMI Transmitter (recognized by OBS as "HDMI Encoder (2): 1920x1080 @ 1920,0") plugged into the HDMI out on a HP Laptop running Windows 10 (64-bit)
The transmitter has one straight through HDMI port that connects to a nearby TV. It transmits to two separate receivers, each is connected to one TVs.
In OBS, preview is enabled; under "Fullscreen Projector (Preview)", "HDMI Encoder (2): 1920x1080 @ 1920,0" is selected. At this point the preview screen appears on all three TV screens. We have had this arrangement active for over two hours at a time without any problems.

When we record, after about 20 minutes, the screen on the laptop momentarily goes black for about .5 seconds, comes back on for about 1-2 seconds then black again for a split second; then comes back on. A moment later, the TV screens all go black and they reset themselves for HDMI signal taking 12-15 seconds. The indicator lights on the transmitter do not react to the break in signal. (We are unable to see the lights on the receivers as they are behind the TVs.)

If we are still recording this cycle can repeat itself but it does not appear to be consistent. Often it occurs again around the 42-45 minute mark, but occasionally there have been two interruptions within 5-7 minutes.

This only occurs when we are recording, so it appears to us to be something in OBS, but we have been unable to see anything in the settings related to the issue.
 

konsolenritter

Active Member
Okay, its clearer now. The transmitter with the (direct thru) connected tv (not the slave ones) is the one the windows laptop sees, right? And in Windows you have setup an advanced, widened desktop, not duplicating, right?

The special quirk with HDMI is that the responding/receiving side (the transmitter or the direct-thru connected tv) tells the sender/source (the laptops graphics) its current capabilities. So if that information sink decides to change something or going to suspend/sleep/powersafe whatever it means a configuration change to the sending side, the windows desktop.

I know its totally annoying. But that means that everywhere in your signal chain the culprit may sit that causes this.

I know that some hdmi extenders (either cable or wireless) support a configuration menu where the customer may simulate or emulate a fix sink configuration. Something like telling "In every case its a 1920x1080/50 thing here. Please ignore if something different is yelled out."

AFAIK there is no mechanism in OBS depending on runtime during recording that changes behaviour on the preview/rendering output bus/bar. Maybe someone other here in the forum knows better.

Ensure that all, i mean all, devices down the chain do report the same framerate like your production in OBS. For instance if you produce in 29.97fps, all the tvs, the hdmi transmission line itself and your gpu card should report those 29.97 as current framerate. Even a small difference between 29.97 and 30 may mean something like a buffer underrun over a couple of minutes.

Additional proof, if the tvs in the last minutes before "ticking out" are the same amount of delay off regarding lipsync (audio) as they were in the second minute after recording starts.
 

Billv4875

New Member
Thanks for the information. We accidentally discovered a "fix". We recorded our service on July 3, and after 30 minutes had not had the issue. Confused, we checked everything and realized we were running on battery power, as we had forgotten to plug in the AC adapter. We finished the service, just over an hour with no problems. We repeated it July 10, with the same results. After that service we plugged in the AC adapter and started recording again, and just after 20 minutes the monitors went off. We checked the settings on power saving and they are the same for battery and powered, everything is on "never". Still at a loss as to the problem, but since everything works on battery power, that's good enough for now. It is curious that it only happens while recording on OBS.
 
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