Video captures

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tomaitheous
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Video captures

Post by tomaitheous »

I had been toying with the idea lately, of making video captures look more like a real TV set. There's a... I guess a common attitude that capturing video from a real console, show it more 'correctly' or authentic. But that's not really true. It might be capturing composite or RF video, but it doesn't actually look like an old SD set. Not really. If anything, it looks worse than emulation sometimes - as capture card software tends to apply all sort of filters - with the purpose of display less than spectacular old TV signals on a PC or such. Not a game device.

Anyway, after doing a bunch of other related crap - I attempted to simulate a real TV set as best I could.

Here's my result: http://www.youtube.com/watch?v=vGpgPd4PLv4 (it has scanline effect, so view it 1:1 mode )

That's a PC-Engine game. I'm fairly happy with the setup of filters/effects for that video, so I'm gonna try out some NES, SNES, Genesis captures as well.

So.. just wanted to get some input on this and see if I'm the only one really interested in this sort of stuff.
mic_
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Post by mic_ »

Looks pretty good overall.

Some comments:

* The scanline effect is too pronounced IMO. It should be toned down a bit.
* The edges are pretty sharp. When I think of analog video I think of chroma noise and color bleeding that make some edges look narrower and less sharp.
* The video has weird interlacing artifacts that you wouldn't see if you played the game on an old TV.
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koitsu
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Post by koitsu »

{opinion}
I'm of the opposite opinion -- I really dislike it when people take pixel-based games and apply weird post-processing filters to them to emulate things like CRT TV scanlines, colour/edge blurring, NTSC colour wonkiness, anti-aliasing, "screen bowing" (to emulate a fishbowl-era CRT), etc...

They're "neat" features in the sense that they're a lot like Photoshop filters -- many have no practical use, but do make people go "ooh-ahh".

I'm one of those guys who does things like scales his Nestopia windows to 2x the normal size, and thus the pixels are twice as big (I do this for ease of viewing). I **want** things to look blocky, because that's exactly what they looked like originally (scanlines, colour/blurring, NTSC colour weirdness, etc. are all artefacts of the display and not the console itself). Plus there's some nostalgia to keeping things streamlined this way.

My opinions, surprisingly, aren't shared by most. But I thought I'd mention them in passing just to give you a different viewpoint.
{/opinion}
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clueless
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Post by clueless »

I agree with Koitsu. I dislike the blurring and distortions. I like having nice, crisp pixels when I test ROMs using FCEUX (and other emulators) with the default video processing settings.

I have to remind myself to occasionally test with the "NTSC blurring" (or whatever it is called) video filter and with other emulators, to ensure that my graphics will look OK if used on a "real tv from a real NES".
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Hojo_Norem
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Post by Hojo_Norem »

One thing to watch out for when discussing this kind of stuff is that you really need to take into account how a machine's gfx hardware works internally. Chipsets in machines like the SNES and Megadrive output RGB while other more older ones like the NES and C64 work with PAL/NTSC encoded colour.

It is often observed that the various quirks of the various colour encoding schemes coupled with the various quirks of the GFX hardware are used to produce effects that otherwise may not be possible if the hardware operated on pure RGB.

In the past emulators had fake-ish effects like scanlines and blurring to simulate the effect of a CRT but now some emulators are moving towards a proper emulation of the various colour encoding schemes and even more accurate by emulating the behaviour of the video output circuits. It won't be long until some emulators start emulating the proper effect of phosphor persistence, bloom and white smear... Example linky
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tokumaru
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Post by tokumaru »

I'm a fan of Blargg's NTSC filters, because they are not just stupid blurring filters (which some emulators have), they actually simulate the type of image encoding the consoles use. In my opinion, that aspect IS a part of the console and I like to have it emulated.

The encoding of the video plays an important part on the final quality of the graphics, since many times you can use the color blending to your advantage, making it look like your games have more colors than the console actually allows. Many NES games that had awesome graphics used the NTSC artifacts to their advantage, such as Batman - Revenge of the Joker, a game that doesn't look as good with crispy pixels.
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Bregalad
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Post by Bregalad »

Just to say I agree with koitsu. Well, mabe I don't agree 100%, a bilinear filter or a HQ2x filter is a nice thing to have.

NTSC filters I'm not fond off, because often it introduce more undesired artefacts, but as the other guy said you'd want to check that they don't affect too much your graphics with it.
The worst is PAL artefacts, they are much worse than NTSC. Thankfully no emulator emulates them :)
That's why I play my NES games mostly emulated, and with bilinear or HQ2x filters.
scanlines, colour/blurring, NTSC colour weirdness, etc. are all artefacts of the display and not the console itself)
Just to say this would be right for OTHER consoles, but for the NES, the output is directly a NTSC signal, so no, it's an artefact of the console itself. However, chances are that the people who drawn the graphics did so with no filter in mind.
The encoding of the video plays an important part on the final quality of the graphics, since many times you can use the color blending to your advantage, making it look like your games have more colors than the console actually allows.
Not really. Chessboard dithering will blend the color better with a bilinear filter, however, with NTSC or PAL "filters" weird diagonal lines will appear. Those weird patterns also depends of the colors you use, if they are the same hue maybe they won't appear, making it effective, but then a bilinear filter is as good for dithering graphics.

Not that, of course, the "weird diagonal lines" could be here intentionally but I don't think that was what you were talking about.
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tepples
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Post by tepples »

koitsu wrote:I **want** things to look blocky, because that's exactly what they looked like originally (scanlines, colour/blurring, NTSC colour weirdness, etc. are all artefacts of the display and not the console itself).
I'm with tokumaru. Because the NTSC and PAL NES generate their signal directly in the composite domain, NTSC color weirdness is part of the console unless you're emulating the RGB PPU in a PlayChoice, Famicom Titler, acNES/PocketNES on GBA, or VC/FCEUGX on Wii. The other effects you mentioned, on the other hand, are distractions.

If the section "Artefact Color" in the article that Hojo_Norem linked reminded you of ClearType subpixel font rendering, you're not alone.
Bregalad wrote:However, chances are that the people who drawn the graphics did so with no filter in mind.
Play Blaster Master and look at anything dithered, in both RGB and NTSC modes. You'll see that some parts of the background look almost as colorful as an early Genesis game in NTSC but much plainer in RGB. It's too bad blargg's screenshots in this topic are dead links now.
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Bregalad
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Post by Bregalad »

You'll see that some parts of the background look almost as colorful as an early Genesis game
This was supposed to be good ?

BTW I didn't agree fully with Koitsu, I said the best was simpler filter - that's it.
To be honnest it all depends on the game ! Different games, with different styles of graphics, looks better with different filters. Also what "looks better" is highly subjective.

In all cases, while the "NTSC" effect is debatable, the "scanline" effect in the video mentionned in the 1st post is horrible IMO.
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tokumaru
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Post by tokumaru »

Bregalad wrote:
You'll see that some parts of the background look almost as colorful as an early Genesis game
This was supposed to be good ?
You don't think that colorful is good?
Also what "looks better" is highly subjective.
True. I for example hate upscaling filters like HQ2X. I don't think you can invent details that weren't there in the first place and expect that to look good in every situation. I hate the wobbly edges and rounded corners that are generated as a result.
In all cases, while the "NTSC" effect is debatable, the "scanline" effect in the video mentionned in the 1st post is horrible IMO.
I'm with you there. I've never noticed any visible scanlines in any TV I have ever used and I certainly don't want them in my emulators.

The first game I ever emulated was Sonic 1 on Genecyst, and at first I though the resolution was worse than on my TV. I ended up accepting it wasn't, and that the blurring and the distance I sat from the TV helped the image look better. Blargg's NTSC filters make it possible to get some of that detail back, in a very accurate way, so that's why I like them.
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Post by tomaitheous »

I'm actually in the middle. I like both.

I like the real screen of an SD set because that's what I grew up on (over composite, not RF. I used composite output very-very early on). I like the sharpness of an old RGB monitor too with a tiny bit of bilinear filtering and 25% scanlines. I also like no scanlines at times too, 'cause I grew up with VGA low res games pretty early on (1991). My HD set displays both SNES and PCE composite without any filtering (it's pretty amazing) and no scanlines (the gap effect). I mean, it still have the chroma dot pattern edge transition artifacts for scrolling parts higher than 30hz - but for the most part it's damn near square edge transitions from pixel to pixel. And this is on a 53" HD CRT RP, so them pixels is mighty big.

That said, there are certain consoles that I don't bother playing in filterless or scanlineless or whatever effects. Manly the NES. Because it only had composite output (or RF output). That's the only valid display mechanism. Swapping the PPU is more of hack/mod, than anything else. I think it's a given that all these old game graphics were design with PAL or NTSC display in mind - not what unfiltered emulation shows. I'm not saying this is justification for everyone to take a purist attitude or view, but that it makes such effects like Blarggs filters and such, more relevant or valid.. I guess.

Since this is quite a bit related to the NES, where do you guys fall in.. for the color values themselves? I mean, for NES - do you perfer the RGB values of the RGB PPU for you emulation purposes and development, or you do you use the HSL colormap of the real (non modded or VS systrem) NES? Disregarding scanlines and all that other stuff.

Anyway, *usually* whole point of video capturing composite stuff for people to watch, is to show off what the systems looked like in there normal display BITD. That's pretty much the only point of these video captures (real hardware) and uploads to youtube.
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Post by tomaitheous »

I'm with you there. I've never noticed any visible scanlines in any TV I have ever used and I certainly don't want them in my emulators.

The first game I ever emulated was Sonic 1 on Genecyst, and at first I though the resolution was worse than on my TV. I ended up accepting it wasn't, and that the blurring and the distance I sat from the TV helped the image look better. Blargg's NTSC filters make it possible to get some of that detail back, in a very accurate way, so that's why I like them.
They're definitely there on a real SD set. I mean, the SD sets are interlaced displays, the console is only progressive because it's not shifting the next field to fill the interleaved gap (turning it into an actual frame instead of a field). But the worse the TV, the 'fatter' (vertically) the beam width will be. Even on a good set, it'll never be perfectly on then off gap. That's because you need some overlapping to hide the interlacing 'comb' effect for motion higher than 30hz (also, disregarding bloom that makes the pixels taller as well for brighter colors). 25% scanlines (as most emulators describe it) - it a pretty good approximation if you were to capture a pic and scale it done to a resolution not directly capable of displaying it. 100% scanlines looks completely wrong for game consoles. The only thing I've ever seen like such scanline games were EGA games (low res ran like that) on an EGA monitor (also monochrome terminal monitors).

On a related note: here's a YUV encoding of the PCE's 5bit conversion table compared to emulation RGB table: http://www.pcedev.net/pics/composite_rg ... _chart.png . There's definitely errors in the table conversion (you can see the luma has wrong steps, sometimes backward steps in the scale). Viewing a game on a PCE modified with an RGB amp, would technically be incorrect. Has anyone tested the SNES for this?
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Post by lidnariq »

A blog I randomly encountered recently had done some work on this a couple years ago -- http://www.reenigne.org/blog/ntsc-hacking/ and http://www.reenigne.org/blog/scaling-sc ... emulation/.

That said, I like my pixels sharp, at most with a little bit of 2xSaI or hq2x.
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Post by tepples »

tokumaru wrote:I for example hate upscaling filters like HQ2X. I don't think you can invent details that weren't there in the first place and expect that to look good in every situation. I hate the wobbly edges and rounded corners that are generated as a result.
But I have been known to use Scale2x as a starting point, followed by manual touch-up, to make high-resolution texture packs. Here's an example:

Image
In all cases, while the "NTSC" effect is debatable, the "scanline" effect in the video mentionned in the 1st post is horrible IMO.
I'm with you there. I've never noticed any visible scanlines in any TV I have ever used
I notice interlace artifacts in basketball broadcasts. You too can notice them in standard TV broadcasts: turn on the TV, stare at a sky or other bright area, and slowly move your gaze down. But I don't use "scanlines" effect in emulators because I want the picture on the emulator to be consistent with the picture on my HDTV, which as tomaitheous pointed out doesn't have a "scanlines" effect.

As for palette, I use the NTSC NES palette. Once I even ran an "all colors" demo (was it Loopy's?) on an NES and Nestopia using side-by-side mode (the biggest size for picture-in-picture on my Vizio is half the screen, which reduces the other view to half the screen as well) to get them to line up properly.
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Post by tokumaru »

tepples wrote:But I have been known to use Scale2x as a starting point, followed by manual touch-up, to make high-resolution texture packs.
Combined with manual touch-ups these filters can produce nice results. What I don't like are the results of automatic filtering of complete game screens.
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