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-   -   My new LG UP81 TV sync huge problem. (https://duc.avid.com/showthread.php?t=418561)

Piotr Kubiak 01-13-2022 10:26 AM

My new LG UP81 TV sync huge problem.
 
I just replace my old LG 55" with new 70" (LG up81) tv for Video monitoring.
I set the monitor in low latency - games mode and measured the latencies by the "catchin'SYNC" program. I delayed the 200ms signal in Protools and everything is fine ... Unfortunately, not for long. The TV is unsynchronized every 10-15 minutes (up to about 500ms), it helps to turn it off and on. I never had such a problem with the previous one. I have already turned off everything that was set to auto, IQ... This is horror... Has anyone had such a problem?

Frank Kruse 01-14-2022 12:55 AM

Re: My new LG UP81 TV sync huge problem.
 
200ms (5 frames) seems like a lot but not unusual. The biggest offset in my room is 20qf (also 5 frames) (to my projector with an HDMI-splitter in between)

When you say "delayed the signal" do you mean the video sync offset setting in PT or are you actually using a delay or moving your audio? When you say "unsynchronised every 15minutes" you mean after playing continuously for 15min or after working for 15min starting and stopping? The former would be drift and is also normal if your system isn't genlocked but drifting from 200ms to 500ms (almost 8 frames) would be a lot even for an un-locked system). But first clarify what you mean please.

These modern screens are computers as well so it might be possible. The fact that the delay changes without you changing settings would be a reason to abandon it, an offset is not a problem, PT can easily compensate for it.
First make sure you're not missing a setting. Turn off all the weird noise reduction, "fluid motion" and other nonsense "better-maker" settings on the TV. Also: What's you video output card?

Piotr Kubiak 01-14-2022 02:46 AM

Re: My new LG UP81 TV sync huge problem.
 
Quote:

Originally Posted by Frank Kruse (Post 2625412)
200ms (5 frames) seems like a lot but not unusual. The biggest offset in my room is 20qf (also 5 frames) (to my projector with an HDMI-splitter in between)


Yes it is alot. I working on post for over 15 years now, I dont remember how much lag was on my first LCD 42" (that was simply tv and I use it even now in my studio B, I must check), but my last one 55" has 250ms (after turning off all "true black, true motion, true something...."). LG 70up81 (the newest one) has option for games that I use right now and after measurement with catchin sync it is 200 ms. I thing something is wrong with my system becouse it will be imposible to play in games with so high lag! I found some information that that TV in game mode has about 10 ms lag. I have about 10m hdmi cable that is connected to my mac 5.1 with Blackimagic Intensity Pro card.




Quote:

Originally Posted by Frank Kruse (Post 2625412)
When you say "delayed the signal" do you mean the video sync offset setting in PT or are you actually using a delay or moving your audio? When you say "unsynchronised every 15minutes" you mean after playing continuously for 15min or after working for 15min starting and stopping? The former would be drift and is also normal if your system isn't genlocked but drifting from 200ms to 500ms (almost 8 frames) would be a lot even for an un-locked system). But first clarify what you mean please.


I mean video sync offset. Sync changing after working (a lot of start/stop) even on the some project in PAL HD. On the exacly some system with old TV it was no problem for 6 years.


Quote:

Originally Posted by Frank Kruse (Post 2625412)
These modern screens are computers as well so it might be possible. The fact that the delay changes without you changing settings would be a reason to abandon it, an offset is not a problem, PT can easily compensate for it.
First make sure you're not missing a setting. Turn off all the weird noise reduction, "fluid motion" and other nonsense "better-maker" settings on the TV. Also: What's you video output card?


I turned off everything, it was alot of. I know it is huge problem that delay is changing without changing setting. Maybe it is a bug in LG firmware. BTW, I working alot with animation and lipsync :)

Frank Kruse 01-14-2022 04:48 AM

Re: My new LG UP81 TV sync huge problem.
 
Yeah that does seem a bit scary. My LG screen as a different offset for almost every setting you change but then it will maintain it. I'm at 12qf on my LG screen, 20qf with the projector.

Also check that you have the latest BM driver, I remember very old ones had huge offset and issues keeping it.

its2loud 01-14-2022 07:34 AM

Re: My new LG UP81 TV sync huge problem.
 
This could be an issue with your Blackmagic card. Also, what video codec are you working with in Pro Tools?

Like Frank said, 200ms or 5 frames is not a lot. I wouldn’t worry about the amount of latency you’re dealing with. I’d try and fix the fact that it keeps changing. A 10 meter HDMI is a long run fir HDMI.

This could be part of the issue.

Piotr Kubiak 01-14-2022 08:58 AM

Re: My new LG UP81 TV sync huge problem.
 
HDMI cable can't be issue - It work for 6 years without problem. I use DNXhd 36 LB for video.

Ok so:
1. I upgraded Blackmagic Card Driver
2. I reset TV to factory setting
3. I change HDMI input in TV.


I checking sync every 30 minutes. All day, no issues! I have now 200 ms latency on non game mode (before that I have 500ms). I don't test game mode now, becouse of deadlines. Hope will be ok now. Fingers crossed.
Thanks for Your help!

thierryd 01-14-2022 12:23 PM

Re: My new LG UP81 TV sync huge problem.
 
Quote:

Originally Posted by its2loud (Post 2625428)
A 10 meter HDMI is a long run fir HDMI.
This could be part of the issue.

10m cable can’t be part of the problem (variable sync) here. Also 10m of cable doesn’t “add” latency…sound through air travels slowly, but signal through a cable is lightning fast:-) FWIW we run 25m unamplified HDMI in some setups with quality cable and it works for HD video. We als run various other setups with HDMI converted and running over SDI or ethernet. Latency for every setup is different, but consistent once set up (PT video sync offsets between 0 an 20 depending on setup).
Solutions for OP are indeed to be looked for in TV and BM drivers as others have mentioned. Of all settings to turn off in the TV (and the list of “enhancement features” seems to grow with every new model), be sure to to uncheck the frame interpolation or motion smoothness modes (if applicable).

Piotr Kubiak 01-15-2022 09:14 AM

Re: My new LG UP81 TV sync huge problem.
 
Second day and it's still in sync!
I guess the reason was either bug in TV firmware (I reset to factory setting) or Blackmagic old driver. I was sure that HDMI cable is ok. I have two of them: 10m and second 20m for ADR room.

Thanks for your help!

its2loud 01-15-2022 09:16 AM

Re: My new LG UP81 TV sync huge problem.
 
Quote:

Originally Posted by Piotr Kubiak (Post 2625495)
Second day and it's still in sync!
I guess the reason was either bug in TV firmware (I reset to factory setting) or Blackmagic old driver. I was sure that HDMI cable is ok. I have two of them: 10m and second 20m for ADR room.

Thanks for your help!

Glad you were able to get it sorted without replacing the HDMI cable. The only reason I mentioned it in the first place is because I've had issues with long HDMI cable runs in the past. Just all a part of the troubleshooting process.


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