BSNES (rules) - Page 3

JadussD · 01-07-2006, 11:00 AM

> I plan to eventually write an article explaining why it
> takes 2ghz to emulate a system with a 2.68mhz processor
> accurately.
>

For those curious, I looked at the source code and from what I can tell, the reason this emulator is so accurate is that it doesn't just emulate one instruction in the processor, then check the other elements in the system individually, it literally updates everything as it should be on each clock cycle, and individual CPU instructions can take up more than one clock cycle, so if you're not updating everything to where it should be on each clock cycle, like most emulators, it'll be a lot faster than what this emulator does, with some accuracy sacrificed. I wouldn't bitch about the speed people, there is no way this could be very much faster than it is. It's the price you pay for an ultra-accurate emulator.

(wraith_) · 01-07-2006, 04:06 PM

Gotta hand it to you byuu, this is very nice.

Runs very well on my 2.2ghz Athlon 64.

After reading the other posts, I was surprised to see my USB sidewinder worked just fine!

And I love the color accuracy... can't wait to see it with TV scanlines.

Any plans for savestates (or did I just miss the options for it in my giddiness)?
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Dark Knight Kain · 01-07-2006, 07:56 PM

<blockquote>In reply to:<hr>

Yeah, I like the color curve a lot myself. Check out the curve with true TV-like scanlines:
http://byuu.cinnamonpirate.com.nyud....emp/hqscan.png

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That looks great <img src=smilies/thumb.gif>

<blockquote>In reply to:<hr>

I can't really do much about speed, but even a $100 processor off eBay can achieve 60fps with no frameskipping. If you don't want to upgrade to use bsnes, I understand.

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If I was still into PC gaming chances are I would've already upgraded but now-a-days I just see it as a waste of money.
---
-Dragonsbrethren

Disch · 01-07-2006, 10:24 PM

> Yeah, I like the color curve a lot myself. Check out the
> curve with true TV-like scanlines:
> http://byuu.cinnamonpirate.com.nyud....emp/hqscan.png

I dislike the black-line-every-other-line method of emulating TV scanlines -- mainly because it looks absolutly nothing at all like how a TV looks (yet strangely... people seem to think it does... *shrug*) Though that screen is significantly better than most (you seem to be doing some interpolation aside from just inserting black scanlines?)

There actually has been some work on the nesdev scene to produce an actual TV-esque image. I don't mean the tradtional crap scanline method -- I mean simulating genuine NTSC rastering techniques.

The image here is a good example of Blaster Master in an emu with such a feature

--edit-- removed and placed in a reply to this post -- wanted to upload as an attachment rather than drain blargg's bandwidth

I don't know of anything that's gotten closer to a true TV image.

The thread in question which discusses the methods used for rendering (and possibly some source links -- although I haven't followed the thread that closely) is here:

http://nesdev.parodius.com/bbs/viewtopic.php?t=871

Check that out if you're interested in putting in a TV filter in your emu -- as it's likely the best existing method -- or at least the right track to focus on.

Why anyone would want to toss out the sharp picture of a monitor and replace it with the dull, hazy picture of a TV is beyond me though. But to each his own.

Disch · 01-07-2006, 10:27 PM

The previously mentioned NTSC TV filter in an NES emu (Blaster Master) :

C:Serverxampphtdocszopharoldwwwthrea...tsntsc_nes.png

Disch · 01-07-2006, 10:33 PM

> http://www.bluemsx.com/features.html (check under blueTV)

Doh! Wish I checked that before I made my post. Seems the boys at nesdev may have gotten the idea from there (or at least had the same idea).

Are there any full-size screenshots of that filter in action? The little itty-bitty clips they give in that section don't really give me a decent feel for it -- and I'm not about to download it just to check that.

byuu · 01-08-2006, 01:50 AM

JadussD is exactly correct.
I wrote up that description. You can find it here:
http://byuu.cinnamonpirate.com/?page...&bg=8&browser=
Please don't complain about contradictions or false statements, I'm not a machine myself so I can't exactly narrow down why the program runs as slowly as it does.

Thanks (wraith), by chance do you have a 3500+? I just upgraded to exactly that, myself. And only because Microcenter was out of 3700+s. To be honest, it's nowhere near 75% faster than my old 2000+, as the bullshit marketing numbers would suggest. I'd say 35-50% faster, which is more in line with the MHz difference.

Sadly, I just nuked the scanlines. They totally die on this lousy Radeon 7500 I'm forced to use (no AGP slots on my new mainboard). Planning to buy a GeForce PCIe with my tax return. I'll probably add them back then.

Savestates will get in there eventually. I'm kind of hesitant to start on them because I don't know how I want to do them yet. I can get into specifics if anyone actually cares.

Disch, I take it you've never actually stared at a TV from < 3" away before? My screenshot is almost exactly how a real TV does scanlines. That screenshot did nothing for RGB->NTSC->RGB, dot crawling, color subcarrier bleeding, etc.
It simply added scanlines. And that's almost precisely how a TV renders them.
Basically, a TV in non-interlace mode will draw every other scanline. The scanlines that aren't drawn are pitch black, not a darker luminance of the scanline above it. However, the scanlines that are drawn tend to bleed into the black scanlines, this is known as the kell effect. Basically, you end up with ~70% of the two scanlines being fully colored, and 30% being solid black.
My screenshot used a 2:1 colored:black ratio, giving you ~67%, which is pretty damn close to a TV.
It doesn't entirely look like it, because CRT monitors are inherently different than CRT televisions...

That picture you posted looks really good, though. I'd like to add color bleeding and that dot crawl eventually to bsnes. But speed is preventing me from adding such filters now.

Sorry for posting my reply to everyone here, but I can't stand boards that mix threaded and collapsed views, and see no reason to post three different replies.

(wraith_) · 01-08-2006, 04:21 AM

> Thanks (wraith), by chance do you have a 3500+? I just
] upgraded to exactly that, myself. And only because
> Microcenter was out of 3700+s. To be honest, it's nowhere
> near 75% faster than my old 2000+, as the bullshit marketing
> numbers would suggest. I'd say 35-50% faster, which is more
> in line with the MHz difference.

My bad, I have the 2.0 ghz (3200+)... bought it months ago and have since put together machines for friends/family--got mixed up with what I went with myself. Prices keep falling and I may have to upgrade again

.

> Sadly, I just nuked the scanlines. They totally die on this
> lousy Radeon 7500 I'm forced to use (no AGP slots on my new
> mainboard). Planning to buy a GeForce PCIe with my tax
> return. I'll probably add them back then.

Rough business, no AGP. At this point, you're almost better off to wait and get a PCIe... kinda wish I had had the cash to go that road myself (Indigo Phophecy won't run well at max res on my Radeon 9800... games are starting to catch up with processor/gpu speed!)

> Savestates will get in there eventually. I'm kind of
> hesitant to start on them because I don't know how I want to
> do them yet. I can get into specifics if anyone actually
> cares.

I'm sure it's complex, where your emu has such specific timing and accuracy. It's not really a necessity (obviously (unless you use them to cheat, haha)), but it makes life much more convenient when you need to get away quickly and the save point is far, far away.
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D-- · 01-08-2006, 05:42 AM

> There actually has been some work on the nesdev scene to
> produce an actual TV-esque image. I don't mean the
> tradtional crap scanline method -- I mean simulating genuine
> NTSC rastering techniques.

What about PAL?
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D-- · 01-08-2006, 05:44 AM

> I'm sure it's complex, where your emu has such specific
> timing and accuracy. It's not really a necessity (obviously
> (unless you use them to cheat, haha)), but it makes life
> much more convenient when you need to get away quickly and
> the save point is far, far away.

For the love of fuck, just don't GZIP them. It's such a pain in the ass to have to GUNZIP every save from Snes9x and ePSXe, edit, then recompress just to test anything.
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