All modern LCD TVs display Amiga PAL RGB perfectly - true or false?

[BuckoA51]

I'm a little late to the party here as I haven't checked in on the forums for a while, but I think I can offer some insight based on my own experiences and research.

So that you could today walk into any home electronics store with an Amiga and easily find a modern LCD TV that will display Amiga PAL RGB via Scart correctly, ie. Workbench will look sharp and games will perform without stutter and look nice.

That statement is false. Though, it all actually depends what you mean by "nice" or "correctly".

Let's go over a few things. Firstly we all know how interlace works right? One refresh sends an odd set of scanlines, while the next sends the even line. HDTV's are inherently incompatible with this, so content must be deinterlaced. To deinterlace to a flicker free image takes time, at least one frame must be buffered, so there will always be an input lag penalty.

Now, the Amiga's non-interlace modes (that virtually all games use) worked by creating two identical interlace fields, so basically the signal is an odd and even interlace frame that are overlaid on top of each other. That's where those scanlines come from on the TV as they are basically the empty lines that would have been filled with one of the interlace frames on a normal 480i or 576i image. Typically these days we refer to this mode as 240p or 288p.

To correctly process a 240 or 288p image, it should be line-doubled to 480p then upscaled, rather than put through the same deinterlacing process that 480i content goes through. If you deinterlace 240p content, you get the input lag hit obviously, and it can mess up plenty of other things, like drop shadows, sprite effects, scrolling and it just generally looks pretty bad compared to a CRT.

I personally believe that no HDTV on the market 'correctly' handles 240p or 288p content. Now, I can't prove this since I don't have every single TV to hand to test. The reason I believe this is because proper 240p/288p processing would add to the cost of the TV set, and it is something that only a tiny minority of people would use anyway. Most people never connect old games consoles and those that do many won't worry that the picture isn't correct or has input lag. For the rest of us, an upscaler like the XRGB series is the only option (that or stick to a CRT).

Of course as we've seen, how kind HDTV's are to 240p and 288p content varies widely. On some sets it looks reasonable despite the above caveats, on other sets it looks utterly hideous. Some more recent HDTV's won't display 240p or 288p content at all. One persons definition of a "nice" picture is different to another. I accept I'm a picky bast, but no HDTV will ever look as good as a reasonable CRT when displaying 24p/288p (without an XRGB or something similar anyway).

You also mention stutter, stutter is often caused by vertical refresh rates being out of spec. When you put the Amiga in 60hz mode, for instance, it's vertical refresh is around 59.2, that's a way off the NTSC spec which is 59.94. CRT's were much more tolerant to this but HDTV's often struggle, and so the stutter in the scrolling you see is due to a frame-rate conversion or mismatch. The same can of course happen if your PAL vertical refresh is too far off spec and some TV's are more tolerant than others.

Phew, hope that helps answer your question anyway.

[Photon]

I know all this and you can see the results of the test program. But sometimes knowledge needs a reality check, because it can get too old. Normally, as long as the technology works on the same principles, new models each year change very little and your knowledge is still current.

This poll was created from the claim that in 2010, the technology changed and all Full HD LCD TVs in stores manufactured 2010 or later would display Amiga PAL RGB fine. Because I don't have a recent LCD TV, and I thought others had and could say if LCD TVs are great Amiga displays now.

[BuckoA51]

Yeah the problems with 240p/288p are well known. The problems with non-spec vertical refresh are not so widely known.

If anything I'd say it's getting worse as I have heard of more and more sets that don't display 240p/288p at all.

[demolition]

Although it is a bit OT here, it's not completely I think.. I got myself a Hauppauge USB-Live2 to be able to connect a C64 to the PC with Composite or S-Video. It works with neither signals and I'm guessing the C64 non-compliant PAL output is the reason for this. It works fine with the Amiga composite output in non-laced PAL however. When you go slightly off spec, it will be a gamble as to how well stuff works together.

[Photon]

That looks more like a device to digitize VHS/DVD, though. I wouldn't expect anything but low fps and buffering from its software, though there's nothing impossible in theory about it sampling with a 1/50 s delay, provided your PC monitor syncs to 50/100/150Hz.

And yes, I guess it's a bit off-topic, or at least the point of the thread isn't to warn what not to buy, but to hilight recent LCD TVs that actually do display Amiga well.

[BuckoA51]

It works with neither signals and I'm guessing the C64 non-compliant PAL output is the reason for this.

Certainly possible, the Blackmagic line of capture cards are notorious for this too and will give a blank screen with anything more than a tiny bit off spec.