Connecting both a CRT tv and a led tv through direct video using a scaler

Discussion about displays and related hardware including MiSTer filters and video settings.
User avatar
Allejo
Posts: 18
Joined: Wed Jan 25, 2023 6:57 pm
Has thanked: 15 times
Been thanked: 7 times

Connecting both a CRT tv and a led tv through direct video using a scaler

Unread post by Allejo »

Hi guys, currently I connect my Mister to the component connectors of my CRT tv through the IO board and to my led tv through the HDMI out for the DE-10 nano.

What I was thinking of is if it was possible to enable direct video and configure mister to output a YPbPr signal, then connect a HDMI -> VGA adapter on the HDMI Out of the de-10 nano, then connect an VGA splitter on the adapter to duplicate the signal, then on one of the outputs of the splitter connect a VGA -> component cable and connect that cable to the CRT tv, but on the other output of the splitter I would connect another VGA -> component cable, then I connect this cable to a scaler, like GBS Control, OSSC or Retrotink, and then connect the scaler to the led tv through HDMI.

Would this be feasible? Has anyone tried it before? Would it add too much lag or would there be any other downsides? I think that with the upcoming Retrotink 4k we would have VRR and HDR so maybe I wouldn't lose any of those nice features from mister.

If this works I could have 24 bit colors on the PSX core and 2 sticks of ram if it's needed in the future, but at the same time outputting to a CRT tv and a modern led tv

I know my post might be a little confusing, so I made a crude picture to illustrate what I meant:

lDunwip.png
lDunwip.png (2.67 MiB) Viewed 53 times
FoxbatStargazer
Top Contributor
Posts: 995
Joined: Thu Dec 10, 2020 5:44 pm
Has thanked: 309 times
Been thanked: 228 times

Re: Connecting both a CRT tv and a led tv through direct video using a scaler

Unread post by FoxbatStargazer »

You can't put HDR or VRR into an analog signal, you're absolutely going to lose that stuff doing HDMI->VGA conversion (or pulled directly from the mister's own VGA out.)

The second issue is that you are going to lose sync-on-green doing direct video, which will mess up your component breakout cables. You need a circuit or device to add sync-on-green before you go to the VGA splitter. You could just use the mister's analog out with its own SoG and skip the HDMI->VGA converter, but I'm guessing you want the 24-bit color or something (only relevant on a few cores, but e.g. if you want to remove dithering on playstation, kind of needed.)

User avatar
Allejo
Posts: 18
Joined: Wed Jan 25, 2023 6:57 pm
Has thanked: 15 times
Been thanked: 7 times

Re: Connecting both a CRT tv and a led tv through direct video using a scaler

Unread post by Allejo »

FoxbatStargazer wrote: Sat Jun 10, 2023 7:44 pm

You can't put HDR or VRR into an analog signal, you're absolutely going to lose that stuff doing HDMI->VGA conversion (or pulled directly from the mister's own VGA out.)

I was thinking of Retrotink, it seems the 5X has VRR support now and they will add HDR support for the upcoming Retrotink 4k.

FoxbatStargazer wrote: Sat Jun 10, 2023 7:44 pm

The second issue is that you are going to lose sync-on-green doing direct video, which will mess up your component breakout cables. You need a circuit or device to add sync-on-green before you go to the VGA splitter. You could just use the mister's analog out with its own SoG and skip the HDMI->VGA converter, but I'm guessing you want the 24-bit color or something (only relevant on a few cores, but e.g. if you want to remove dithering on playstation, kind of needed.)

Yeah, I didn't notice the need for a sync-on-green on the connector itself, one solution (kind of) would be to output a RGB signal from the Mister, and then after the VGA splitter I connect a VGA-SCART cable to a SCART to YPbPr transcoder.

But anyway, I don't think any of this is feasible anymore, the main reason I connect my Mister to both my CRT tv and my LED tv is because the LED tv can play games that the CRT either can't play or doesn't play very well, e.g. vertical arcade shooters that can't be rotated on the CRT, consoles that don't output a 15Hz video signal like the Vectrex, and the portables like the Game Boy, with their very small screens on the CRT.
If I do what I suggested on my original post, I would be able to output image on both tvs, but since Mister will be outputting a analog signal, I'll get the same limitations from the CRT to the LED tv.

So, TLDR: my original post was a bad idea, I didn't think it through when I wrote it.

Thank you for your help though.

Post Reply