Matching frame rate causes black screens and lag. Ok to leave off?

[richard371]

I notice there are black screens for a few secondsand lag when turning on matching framerate. I prefer SDR 60 as my default setting with matching dynamic range on. When I turn it off there are no more black screens when going through videos etc. Is there any disadvantage to leaving it off? I have an ATV 4k second gen with an 2017 LG OLED65C7P.

Thanks

 

[waw74]

it's the TV adjusting to the new frame rate or dynamic range, it happens on all sets, the TV manufactures have fixed some of it, I have a CX (2020 model) and it is quicker about it than older sets. I had a C6 before, and the CX is definitely much quicker about it. about 1 second vs maybe 2-4.

I find it worth it though, If you don't match rate, the aTV will have to double some frames, since it's outputting more frames that the source is putting in. Your eye will definitely see it, most noticeable in long slow panning shots. With 24fps content showing in 30fps, it's got to come up with 6 frames to fill them all, so the aTV will double every 4th frame, it will send 1 2 3 4 4 5 6 7 8 8 and so on. your eye will interpret that extra bit of screen time as a small pause in movement.

for 60 it just doubles every frame that 30 would show, so 24 content in 60 will do 1 1 2 2 3 3 4 4 4 4 5 5 , leading to basically the same viewing experience as 30.

the technical term for this is "judder" if you want to look up more

there is no magic algorithm (yet) that will actually generate the extra frames needed to make lower frame rates have the smoothness that higher frame rates do, at least on the fly as you're playing something.

I have both match rate and range turned on, and I just deal with the dropout.
I just wish they put the screen saver at whatever it's already outputting like it used to before last year. currently if you have a video paused, it will change back to whatever mode is in the setting menu for the screen saver. so you get the dropout when the screen saver starts (not a problem, since I'm not looking at the TV) and also again when you stop the screen saver (annoying, since I'm now trying to pick my show back up)

 

[richard371]

Very helpful thank you. I’ll turn it back on.

 

[Jus711]

I notice there are black screens for a few secondsand lag when turning on matching framerate. I prefer SDR 60 as my default setting with matching dynamic range on. When I turn it off there are no more black screens when going through videos etc. Is there any disadvantage to leaving it off? I have an ATV 4k second gen with an 2017 LG OLED65C7P.

Thanks

I have an E7 and don’t notice this issue and I have both match frame rate and dynamic range on. However I have everything routed through my receiver before the TV, maybe that’s it or maybe it’s the cable, have you tried a different HDMI cable?

 

[waw74]

do you get the dolby vision badge when playing something with dolby vision? (or if you've got the main video settings set to DV, do you get the badge when you stop playing something not HDR)

or if you've got media paused, and the screen saver comes on, when you exit the screen saver, do it do a little animated fade between the 2 images? or a bump to black, and then a bump to the media.

it's possible the receiver is doing something to the signal, and converting everything to some setting you've made on the receiver. Does your TV go in and out of DV as you play different things? you should get the little badge when you start DV, and it will be in the info bar that you can access with the TV remote.

 

[Jus711]

do you get the dolby vision badge when playing something with dolby vision? (or if you've got the main video settings set to DV, do you get the badge when you stop playing something not HDR)

or if you've got media paused, and the screen saver comes on, when you exit the screen saver, do it do a little animated fade between the 2 images? or a bump to black, and then a bump to the media.

it's possible the receiver is doing something to the signal, and converting everything to some setting you've made on the receiver. Does your TV go in and out of DV as you play different things? you should get the little badge when you start DV, and it will be in the info bar that you can access with the TV remote.

Yes I get the DV badge on the TV (I have it set to 4K SDR), there have been a couple of shows on Disney + where the screen did go black and didn’t come back and I had to switch out of the app and re-play it and for one episode of Wandavision I actually had to set it to 4K DV in the  TV seeing to get it to play, but for the most part it’s fairly seamless switching in and out, maybe a slight pause

 

[rillrill]

I’m glad I found this thread. I recently bought a 2021 Samsung 4k tv and with the 2017 atv 4k I get this too. Does the new atv fix this? I also use match content. My 1080 TVs never did this.

 

[waw74]

Does the new atv fix this?

it's not the aTV, it's the TV

The aTV switches almost instantly, the blackout comes from the TV changing to match the new signal.


tl;dr - No

My 1080 TVs never did this.

on your 1080 tv did you have match rate turned on? (I'm guessing it didn't have HDR)

if not, then this problem never occurred, because the video signal never changed.

if you did, TVs seem to handle rate changes better than range changes.

 

[frumpsnake]

For what its worth, while I personally have 'Match Frame Rate' turned on, there are plenty of TVs that can detect 24p (or 25p PAL) cadences inside a 60Hz output signal, and adjust accordingly to remove the repeated frames and avoid judder. (This is a wholly separate feature to 'Motion Interpolation'.)

RTINGs.com TV tests explicitly test for this on all TV reviews with their 'Judder-Free 24p via 60p' test, and this is what Apple are referring to with the "some TVs do this automatically" help text.

While I would always keep Match Dynamic Range turned on, if your TV removes (or you otherwise don't notice) the frame rate mismatch, there's no harm in keeping it off.

 

[rillrill]

it's not the aTV, it's the TV

The aTV switches almost instantly, the blackout comes from the TV changing to match the new signal.


tl;dr - No


on your 1080 tv did you have match rate turned on? (I'm guessing it didn't have HDR)

if not, then this problem never occurred, because the video signal never changed.

if you did, TVs seem to handle rate changes better than range changes.

Thanks for the reply. You saved me $200. This blackout pause thing drove me nuts. Nice to know its not really fixable with my tv. Just something i will have to get use to.

the 1080p tv is older and definitely not hdr. So i guess thats why it never had this problem.

 

[oneMadRssn]

HDMI 2.1 includes Quick Media Switching ("QMS") which allows near instant changing of the frame-rate and HDR settings without the long blackout. Any TV with HDMI 2.1 should have this.