| |
Golara Account closed
Registered: Jan 2018 Posts: 212 |
C64 on LCD with svideo
Did anyone try using LCD monitor or TV with svideo input ? I'm not talking about using external converters to VGA or HDMI. Do they really handle 50Hz analog signal or they do some VGA conversion inside, how is the quality ?
Example of such monitor
I've got a really good Sony TV with Svideo, but it's a bit too big for my liking (26") It's so hard to find 21" or thereabout TV with Svideo :( Also, are there any CRT monitors with additional Svideo besides the standard VGA ? I think that would be perfect. |
|
| |
Dano
Registered: Jul 2004 Posts: 231 |
i would say, get a retrotink 2x and with the resulting hdmi you should have way more monitors to choose from. |
| |
Golara Account closed
Registered: Jan 2018 Posts: 212 |
How do they handle the framerate, isn't hdmi and monitors 60 Hz ? Besides I'm talking about very cheap option. Old LCD monitors with Svideo can be had for pennies. |
| |
Oswald
Registered: Apr 2002 Posts: 5086 |
maybe you will like this: https://www.youtube.com/watch?v=RAi8AVj9GV8 |
| |
Golara Account closed
Registered: Jan 2018 Posts: 212 |
Quote: maybe you will like this: https://www.youtube.com/watch?v=RAi8AVj9GV8
Well, I don't need convincing to use CRT as I do have CRT TV with Svideo which produces very good image, It's just that it's a bit too big for the furniture I've got in my room. It's there for couple of months, but a bit smaller TV would make my life a bit easier. It's just so hard to find a small TV with Svideo and I don't want to use composite. PVMs are expensive as fuck, I'm stingy as fuck. Getting old CRT televisor is very cheap and often even free, you just have to go and collect it. I'm looking for ads and auctions for smaller CRT with svideo almost every day but with no luck. I thought of these LCDs as a possible secondary display just in case (but I still want good qood quality) |
| |
Oswald
Registered: Apr 2002 Posts: 5086 |
what I find exciting in that vid is the high end CRTs (up to HD reso) it showcases that I didnt know about. from about 60% of the playtime. since you are after space opimization then sorry for the oftopic :) |
| |
Golara Account closed
Registered: Jan 2018 Posts: 212 |
Quote: what I find exciting in that vid is the high end CRTs (up to HD reso) it showcases that I didnt know about. from about 60% of the playtime. since you are after space opimization then sorry for the oftopic :)
I didn't know these BVMs could display 720 and 1080 either. It was a cool video.
I'm wondering if it's possible to convert Svideo signal to rgb. You'd think that with modern fast, small and cheap electronics it should be possible to read one signal on analog IO, read whole frame to a framebuffer and output it in another analog format over IO. Such thing with one frame delay max would be acceptable. No such device exists and I don't want to call people stupid, so there must be some reason it doesn't exist, I just don't know what it is. |
| |
Oswald
Registered: Apr 2002 Posts: 5086 |
because its mostly pointless outside niche retro HW scenes like us. if you want rgb you get a device which outputs RGB. also I'd guess the conversion will result in loss of quality. |
| |
Golara Account closed
Registered: Jan 2018 Posts: 212 |
Quote: because its mostly pointless outside niche retro HW scenes like us. if you want rgb you get a device which outputs RGB. also I'd guess the conversion will result in loss of quality.
The way I'd do it is like any capture device. Receive Svideo signal, convert it into pixel framebuffer and read it to create analog RGB signal. The key is to do it fast enough to not introduce lag. If you could prepare everything in the vertical blank and read one frame and output another (previous) at the same time there would be only one frame lag. Acceptable for C64 demos I'd say. I wish such thing existed, hell, I could try making it myself. I just want some confirmation from someone in the known if it's even possible. Maybe I'm missing some key thing that makes it not. |
| |
Mr. SID
Registered: Jan 2003 Posts: 424 |
Why use a frame buffer, if you could use a line buffer and only have one line of lag? |
| |
Golara Account closed
Registered: Jan 2018 Posts: 212 |
Quote: Why use a frame buffer, if you could use a line buffer and only have one line of lag?
hehe even better. |
| |
JackAsser
Registered: Jun 2002 Posts: 2014 |
S-video to analog 15khz rgb can be done without digital sampling right.. |
| |
Golara Account closed
Registered: Jan 2018 Posts: 212 |
Quote: S-video to analog 15khz rgb can be done without digital sampling right..
I'm just throwing wild hypotheses based on my understanding of the Svideo and rgb signal and no real electronics experience. I just though it would be easier for me to program such a converter in some assembler than wire it up with individual components. But since you mentioned it and I thought about it for a bit, it seems obvious now.
SVideo and rgb has the same sync signal, right ? The difference is that RGB has a separate sync line while on Svideo the sync is mixed with the luma. That means you need to extract the sync from Luma, then based on the luma and chroma values generate proper voltage on rgb lines (I don't know the "formula" for that yet, need more reading)
The whole point of such converter would be the ability to connect the C64 to any TV with RGB (which is most of them, SCART has RGB). Seems so simple, yet I couldn't find a device that does that. Only the other way around. That's why I think there's some catch to this. If there's none, then why doesn't that exist already damnit 1 :D |
| |
MagerValp
Registered: Dec 2001 Posts: 1074 |
If you want RGB from the C64, go on eBay and get a JVC KM-V7EG or Sony S-RGB YR-1000/3000 transcoder. They're scanline based and don't introduce any lag or artifacts.
To answer the original question, the quality of LCD monitors with S-video varies WILDLY. Some show a decent 50 Hz image with no noticable artifacts, while some have tons of deinterlacing artifacts or motion judder. It's a crapshoot, and in general the newer a monitor is, the less likely it is to work well, in my experience.
The simplest solution today is to get a RetroTink 2x and use a modern monitor with HDMI. And yes, HDMI officially supports 50 Hz. It's given me a nice image on every TV, projector, or monitor I've tried it on, and that's a dozen or so.
Oh and don't forget to enable "gaming mode" on your TV, otherwise latency is going to be unbearable. |
| |
JackAsser
Registered: Jun 2002 Posts: 2014 |
Quote: I'm just throwing wild hypotheses based on my understanding of the Svideo and rgb signal and no real electronics experience. I just though it would be easier for me to program such a converter in some assembler than wire it up with individual components. But since you mentioned it and I thought about it for a bit, it seems obvious now.
SVideo and rgb has the same sync signal, right ? The difference is that RGB has a separate sync line while on Svideo the sync is mixed with the luma. That means you need to extract the sync from Luma, then based on the luma and chroma values generate proper voltage on rgb lines (I don't know the "formula" for that yet, need more reading)
The whole point of such converter would be the ability to connect the C64 to any TV with RGB (which is most of them, SCART has RGB). Seems so simple, yet I couldn't find a device that does that. Only the other way around. That's why I think there's some catch to this. If there's none, then why doesn't that exist already damnit 1 :D
Regarding scart:
Scart is just a connector. It has pins for composite, s-video, rgb and audio. It is by no means any guarantee a TV with scart supports all signals in the connector. |
| |
MagerValp
Registered: Dec 2001 Posts: 1074 |
Converting to RGB SCART to connect to a modern LCD doesn't make sense. You're still at the mercy of the display controller and just as likely to get artifacts as if you use S-Video. If there's even a SCART connector at all.
Just convert to HDMI with a known good device such as the RetroTink. Since it outputs a digital 576p signal there's very little chance of the LCD messing it up. |
| |
Golara Account closed
Registered: Jan 2018 Posts: 212 |
Quote: Converting to RGB SCART to connect to a modern LCD doesn't make sense. You're still at the mercy of the display controller and just as likely to get artifacts as if you use S-Video. If there's even a SCART connector at all.
Just convert to HDMI with a known good device such as the RetroTink. Since it outputs a digital 576p signal there's very little chance of the LCD messing it up.
Well I shouldn't mix up two topics in one thread. When I was talking about converting s video to rgb I wanted to connect it to crt. |
| |
MagerValp
Registered: Dec 2001 Posts: 1074 |
CRTs that accept RGB but not S-video are pretty rare, but if that's what you need you'll be happy with a JVC or Sony transcoder. |
| |
Golara Account closed
Registered: Jan 2018 Posts: 212 |
Quote: CRTs that accept RGB but not S-video are pretty rare, but if that's what you need you'll be happy with a JVC or Sony transcoder.
Are you saying most CRTs with Scart support Svideo on the Scart pins ? I've read is optional and interpreted that as rarely used, since why bother when the spec doesn't require it and you can save some money. If you're talking about CRT TVs having Svideo in 4din being common... Maybe it is where you are from, but here I almost never see them. Sure, more modern 32" + CRTs have them, but I want a small box, I've got a 26" TV with Svideo din, I got it even though it's bit too big because I didn't want to risk not finding another one and I didnt find another since. That's why I started exploring other options. Ideally I would like a small CRT (16-21") with Svideo din socket. |