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PostPosted: Tue Aug 14, 2018 5:33 am 
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tepples wrote:
If the TV license has become a capitation, then why don't governments avoid the additional cost of collecting the TV license and just take it out of income tax?

Everyone is asking the same question.


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PostPosted: Tue Aug 14, 2018 6:40 am 
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That is what is done here, except it comes from the social tax rather than the income tax.

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PostPosted: Tue Aug 14, 2018 8:34 am 
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errr, thread derailed :lol:

So even with a modulator (converter, whatever you want to call it), the tv will be an issue during the upscaling? I played the latest famicom with composite and it seemed fine but maybe I didn't look enough. Maybe the tv we have is better than expected.


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PostPosted: Tue Aug 14, 2018 9:15 am 
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Modern TVs tend to handle 240p signals very poorly. They usually treat it as 480i, meaning that you you get 30 fps video with 2 game frames interleaved together. This totally messes up with scrolling and flickering.


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PostPosted: Tue Aug 14, 2018 7:37 pm 
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What are the kind of scrolling/flickering issues that could be encountered? With the tv we have at the moment, when I played Kirby with the kids with a famicom av, I do not remember noticing anything unusual and was able to finish the game without issue. I do not remember anything that looked like lag too.

As for rf to hdmi modulators, I didn't find any particular yet in Japan but the one I found information on the net, it seems that some may introduce lag. So it's not only the tv that cause lag but the modulator too?


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PostPosted: Tue Aug 14, 2018 7:46 pm 
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I posted a GIF here which shows what 240p intepreted as 480i looks like, in slow motion:
https://forums.nesdev.com/viewtopic.php?p=158915#p158915

The issue isn't a loss of picture or anything, just you get alternating lines, and a framerate reduction to 30fps instead of 60.


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PostPosted: Tue Aug 14, 2018 9:36 pm 
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I looked at the post and sorry to be thick on the subject since I want to be sure that I'm not interpreting the information improperly, the screen capture shown in the referred post, the left side is the 240p -> 480p and would be what I could expect on a tv that have lag issue?

If this is the case then my current television doesn't show such artefact. It's not an high end tv but a basic model from Panasonic.

edit:

I think it's the opposite, the left side is the signal before being de-interlaced and the result on the right nd showed in slow-motion. maybe the tv set drop frames, I cannot confirm until I would try it again on a normal tv set and this new one.


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PostPosted: Tue Aug 14, 2018 10:04 pm 
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The picture on the left is 240p 60 incorrectly displayed as 480i 30
The picture on the right is 240p 60

(Also, GIF previews are corrupted on this forum, so please click on it to see the original image.)

Modern televisions I've used for an NES display an NES picture like on the left. (This is not really intended as an illustration of underlying signals it's exactly what it would look like on the TV. The image itself was taken with a capture device, but the result is the same.)

I've yet to seen a TV that actually does 240p from composite. I've seen 480p60 done through component (e.g. from a Wii), but never composite.

I think some TVs might do additional deinterlacing filtering for 480i to reduce the weave effect (there's a bunch of methods for this), or might even try to do motion interpolation to turn it back into 60fps? I'm not sure. I've always seen modern TVs just treat composite as 480i only, with no extra filtering just alternating rows in weave like depicted in that image.


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PostPosted: Tue Aug 14, 2018 10:36 pm 
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I have a Panasonic TV, and my experience is that it actually does 240p quite well, compared to what you are expecting for a HDTV. Definitely no deinterlacing, and RGB signals look completely crisp.
It's a plasma TV though, I'm not sure if yours are. Not too many of those anymore.

Only drawback is the lack of black scanlines, and a small bit of lag. Not something anyone would notice, but if you're, say, playing Tetris on a very high level, it makes a difference.


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PostPosted: Tue Aug 14, 2018 11:11 pm 
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@rainwarrior

Thank you for clarifying the picture. I'm usually very picky about how thing are shown on the screen and see the difference between 30hz/60hz in game and prefer 60hz so if there would have been such artefact I would have remembered about it. There is a possibility that this tv does a not so bad job at upscaling composite signal even though it's an entry model. I could try to find the manual and see what they say on the subject. I could always someday take a video at 60fps from a phone but I think for now this is not relevant for this thread, since the question was regarding rf on new tv and now how to convert such signal for new tv. We never had issues playing wii game like taiko no tatsujin on this tv, no lag that I can remember.

@sumez

The tv was bought after japan converted all their signal to digital in 2011, my guess around 2012~2013 so most TV (if not all) at that time were LCD. I think they were promoting some new technology for faster panel but it's been such a long time ago that I do not remember the details about it. I think the only way to know more will be to look at the manual or if I ask the manufacturer directly.


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PostPosted: Tue Aug 14, 2018 11:18 pm 
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Here's a slow-motion simulation of what scrolling looks like on my TV:

Attachment:
felix-480i.gif
felix-480i.gif [ 499.77 KiB | Viewed 1323 times ]

This is completely unacceptable.


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PostPosted: Tue Aug 14, 2018 11:49 pm 
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@tokumaru

Ouch. I totally agree. I't not acceptable. Another thing that is maybe less common these days on tv (or maybe it is still there?) is ghosting like I have on my old pc monitor. When I test on emulators and there is a contrasting section of colors in a stage, some part will become darker or disappear, which is annoying since when you stop moving, the color goes back to normal. It only appears during fast movement.


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PostPosted: Wed Aug 15, 2018 3:25 am 
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That ghosting is motion blur inherent to all LCDs, some do it less than others. On my tabletlaptop's IPS panel transitions from dark to bright are much slower than the other way and small details in dark stuff pretty much disappear when things move, highly annoying indeed.

My parents' Panasonic plasma from roughly 2010 timeframe handles 240p as like Tokumaru's example and all other LCD and plasmas I have seen do the same thing. There certainly are some that do it correctly but they seem to be pretty uncommon.

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PostPosted: Wed Aug 15, 2018 8:32 am 
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I did some research on my current television and it is a panasonic th-l32c5 that came out around 2012/02. It contains an ipsα panel with LCD backlight, where ipsα ust seems to be a gimmick name for their Bravia brand. I think it's a common model that came out only in Japan.

There seems that they added something to reduce ghosting so the panel must be fast to some degree. The 32" in only 720p while other where 1080p and from the 37" they could go up to 120fps. I was not even aware of that. It support 480i, 480p, 720p, 1080i.

I just bought the tv because we only had a CRT and needed a digital one fast. Now that I check the review, the one we bought was reviewed very well so I guess we were lucky. One person mentioned in the review that he was concerned about speed but was surprised by quality and felt it was acceptable compared to CRT. The only part is no analog anymore but I guess I just need to figure out what to use to convert the signal.

Now I really want to test it again (I didn't use the famicom in ages) to see if my eyes didn't trick me or something.


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PostPosted: Wed Aug 15, 2018 10:18 am 
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There is to be a list of TVs tested for 240p compatibility here:
https://www.hdretrovision.com/240p/

Seems to be a lot of variation in the results, even between the same brand. I'm a bit surprised how many apparently won't even accept a 240p signal as input in the first place? There are a bunch listed that apparently display 240p quite well, too.

I guess I've been unlucky for not having yet encountered that, but not too unlucky, since I also haven't seen a TV completely fail to produce a picture from it.


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