Anyone try Dr. HDMI or the Monoprice scalers?

[thebigcheese]

I notice they've got Dr. HDMI that is supposed to solve handshake issues like what happens when games switch resolutions: https://www.monoprice.com/product?p_id=14106. I am curious how well it actually works for that, particularly in conjunction with the OSSC or even the Framemeister. It's a little pricey, but if it makes resolution switches practically instantaneous for everyone, could be worthwhile.

They've also got a little 4K scaler that is designed to take resolutions down to 480i over HDMI and scale them to 4K. https://www.monoprice.com/product?p_id=30459. If it does better scaling than a TV's built-in scaler and with less lag, could be an interesting addition to an OSSC setup. Maybe it even solves some compatibility issues, who knows.

Just curious if anyone has tested either of these out.

[nmalinoski]

I've not tried either of these devices, but I do know they will have be of limited use to gamers.

First, the scaler won't be good for gamers, because the 4K scaling maxes out at 30fps; you'd need 60fps to get a proper representation of your games.

And second, while the Dr. HDMI might help if you configure an OSSC to line-double 240p and 480i to 480p, and passthrough 480p, or line-quad 240p/480i and line-double 480p to 960p, so it can maintain a set resolution during 240p<->480i mode switches, I've read recently that there are slight framerate changes between the two, so you might still end up with some resync delay between the OSSC and the Dr. HDMI. I'd try it out, but I'm not willing to plonk down $90 on one of these things for it to not quite work.

On top of that, you would be limited to either 480p or 960p out of the OSSC (probably just 480p, because how much really supports 960p?), because they're the only common resolutions you can get out of 240p, 480i, and 480p. If you change to a different resolution from a different console, like 720p/1080i/1080p, or try to 5x 240p and only line-double 480p, you're going to end up with a resync. It's also not clear how the Dr. HDMI handles this behavior.

If I knew it worked, I'd buy one, but the $90 price is a bit high for the risk of it not doing what we need it to do.

[thebigcheese]

I've not tried either of these devices, but I do know they will have be of limited use to gamers.

First, the scaler won't be good for gamers, because the 4K scaling maxes out at 30fps; you'd need 60fps to get a proper representation of your games.

And second, while the Dr. HDMI might help if you configure an OSSC to line-double 240p and 480i to 480p, and passthrough 480p, or line-quad 240p/480i and line-double 480p to 960p, so it can maintain a set resolution during 240p<->480i mode switches, I've read recently that there are slight framerate changes between the two, so you might still end up with some resync delay between the OSSC and the Dr. HDMI. I'd try it out, but I'm not willing to plonk down $90 on one of these things for it to not quite work.

On top of that, you would be limited to either 480p or 960p out of the OSSC (probably just 480p, because how much really supports 960p?), because they're the only common resolutions you can get out of 240p, 480i, and 480p. If you change to a different resolution from a different console, like 720p/1080i/1080p, or try to 5x 240p and only line-double 480p, you're going to end up with a resync. It's also not clear how the Dr. HDMI handles this behavior.

If I knew it worked, I'd buy one, but the $90 price is a bit high for the risk of it not doing what we need it to do.

The maximum INPUT for the scaler is 4K @ 30 Hz, it outputs at 60 Hz. For the Dr. HDMI, it also supports 720 and 1920x1200 (which is one of the 5x format options), so it could be useful. I see that VGP did a review of it once, gonna see if he might test it for this, too.

[Fudoh]

it also supports 720 and 1920x1200 (which is one of the 5x format options), so it could be useful. I see that VGP did a review of it once, gonna see if he might test it for this, too.

doesn't matter in any way. The resolution you set on the Dr.HDMI device is what the Dr.HDMI reports to the source as it's maximum res. The OSSC ignores this completely. It will neither set an automatic resolution following any EDID data nor will it limited you to whatever you set on the EDID minder.

I've been using a Dr.HDMI with one my DVDOs which would not boot when the TV has a 3D capable resolution listed in its EDID. So I set 1080p60 2D as the max on the Dr.HDMI and this solved the problem.

In short: the Dr. HDMI is a device to fix SOURCE related problems. I don't see how it could help you solve display related problems.

[thebigcheese]

Well, the display loses sync because the OSSC drops the signal during resolution switches. The TV has to reacquire sync when it comes back. As I understand it, this all happens very quickly on the OSSC, so there is almost no time between when it cuts signal out and puts it back, but many TVs, including mine, take a few seconds to reacquire the signal. If you have a device like the Dr. HDMI that tricks the TV into thinking the signal was never dropped, then it doesn't need to reacquire the signal and in theory it should significantly reduce the handshake time when switching resolutions. I could be wrong, of course, but in theory that's what it would help with.

[Fudoh]

If you have a device like the Dr. HDMI that tricks the TV into thinking the signal was never dropped

to my understanding that's not what the Dr.HDMI or any other EDID minder does. If I can dig up mine, I'll give it a try with the OSSC.

[thebigcheese]

That might be the wrong word, but the description says, "It help to keep a source always ON or tricked into a defined state which is especially useful for system integrators." I could be misunderstanding it, but it sure would be cool if it works.

[Fudoh]

yes, but your source (the OSSC) is already always ON. The OSSC is not initiating any handshake shenanigans when switching resolutions.

[thebigcheese]

yes, but your source (the OSSC) is alrady always ON. The OSSC is not initiating any handshake shenanigans when switching resolutions.

Huh, my understanding (based on reading elsewhere, probably hearsay) was that if there is no input signal then it is not outputting anything, either. Specifically, that the signal is dropped while the resolution switch happens, but only for that brief instant. I can't remember where I read that, at this point, but that is what I am basing this all on. I believe somewhere on the VGP forums is where I got the idea that no input signal means no output signal because someone was asking about leaving it on all the time. That part would be easy enough to verify, I have an auto HDMI switcher that switches to whatever input is active, so, if there's no signal on the OSSC output, then it would ignore it, but if there is, it would probably always be on.

[Fudoh]

you're right. There's that tiny glitch caused by the frequency change. But the feature on the Dr.HDMI refers to something else. It refers to cases where the signal is dropped on purpose until another handshake with the display can be initiated and completed.

And what I meant is that the OSSC won't change it's behaviour just because you add anything to the output.

[nmalinoski]

Huh, my understanding (based on reading elsewhere, probably hearsay) was that if there is no input signal then it is not outputting anything, either. Specifically, that the signal is dropped while the resolution switch happens, but only for that brief instant. I can't remember where I read that, at this point, but that is what I am basing this all on. I believe somewhere on the VGP forums is where I got the idea that no input signal means no output signal because someone was asking about leaving it on all the time. That part would be easy enough to verify, I have an auto HDMI switcher that switches to whatever input is active, so, if there's no signal on the OSSC output, then it would ignore it, but if there is, it would probably always be on.

From memory, when the OSSC is first turned on, it automatically outputs the test pattern until either it receives a signal on the default input or you press a button to switch inputs, at which point it either syncs to the active video signal and outputs video, or it shuts off output because there's nothing to sync to.

I believe that is distinct from the resolution switch. My understanding was that, during a resolution switch, the connected devices lose sync and end up taking a few seconds to resync (Which I thought was another handshake, but I'm probably wrong).

you're right. There's that tiny glitch caused by the frequency change. But the feature on the Dr.HDMI refers to something else. It refers to cases where the signal is dropped on purpose until another handshake with the display can be initiated and completed.

So, if you have the OSSC configured to passthrough 480p and linedouble 240p and 480i, and you set the Dr. HDMI to report 480p, it won't prevent signal drops during resolution changes? What actually happens in this scenario?

[Fudoh]

So, if you have the OSSC configured to passthrough 480p and linedouble 240p and 480i, and you set the Dr. HDMI to report 480p, it won't prevent signal drops during resolution changes? What actually happens in this scenario?

the same as without a Dr.HDMI. Why would it change anything, if the OSSC ignores it anyway and the display just reacts to the signal breaks caused by the OSSC ?

[nmalinoski]

So, if you have the OSSC configured to passthrough 480p and linedouble 240p and 480i, and you set the Dr. HDMI to report 480p, it won't prevent signal drops during resolution changes? What actually happens in this scenario?

the same as without a Dr.HDMI. Why would it change anything, if the OSSC ignores it anyway and the display just reacts to the signal breaks caused by the OSSC ?

So then we basically need a scaler between the OSSC and the display that can continually feed the display with some kind of signal while the OSSC switches video modes?

[Fudoh]

Either that (these are called seamless switchers/scalers) or use a capture card that won't mind.

I've seen so many videos on YT documenting the 240p/480i transitions and these have been recorded somehow as well.

[thebigcheese]

I'd still love someone to actually try it. While I don't think I quite understand how the thing works, I'm not certain any of the rest of us do, either. And the scientist in me says we should try it and see.

[Xer Xian]

Yeah. Let's do a blinded experiment

[BuckoA51]

I notice they've got Dr. HDMI that is supposed to solve handshake issues like what happens when games switch resolutions

It's not supposed to solve this issue at all. I think people are misunderstanding what the Dr HDMI does. It's an EDID minder/emulator. It's useful eg for when your PC or PS4 miss-detects your home theatre system and thinks it can only do stereo when it can clearly do surround sound.

It can't help with anything like 240p to 480i transitions. All it does is, in laymens terms, say to your device "hello, I'm a HDMI display that has 6 channel audio and supports 3D".. or whatever EDID you select.

[thebigcheese]

The description of it literally says it solves handshake issues. I wish someone would just try it, probably take like 5 minutes...

[Fudoh]

I can try on monday.

[thebigcheese]

I appreciate it. I know it's probably a nuisance since it's not supposed to do anything to fix this, per you and Bucko, but then again, modern TVs generally read 240p as 480i because 240p was never supposed to be used. All I'm saying is it seems like there is a possibility it could help whether or not it is "supposed" to fix this particular thing, so it's worth trying. If it doesn't, then... oh well. But if it does, could be a game changer.

[orange808]

The description doesn't say a thing about seamless transitions and/or faster handshakes.

Adding another handshake to the chain will probably slow things down even more.

[thebigcheese]

"Dr. HDMI - Solve handshake and compatibility issue"

[BuckoA51]

I appreciate it. I know it's probably a nuisance since it's not supposed to do anything to fix this, per you and Bucko, but then again, modern TVs generally read 240p as 480i because 240p was never supposed to be used. All I'm saying is it seems like there is a possibility it could help whether or not it is "supposed" to fix this particular thing, so it's worth trying. If it doesn't, then... oh well. But if it does, could be a game changer.

They're useful little devices don't get me wrong, I always used one with my PC because Windows is a PITA for suddenly deciding your TV/Home Theatre system you connected can only do 2 channel audio.

but.. the issue with 240p/480i transitions on the OSSC is to do with frame rate changes not handshaking, so you might as well try putting the OSSC upside down or something, it's just as likely to fix that issue as a Dr HDMI.