GP2X How Many Fps Should You Get When Emulating A Us System?


christo930

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Say your emulating a Sega Genesis, which is the proper frame rate 30 or 60? If my memory serves me correctly, you get 60 frames per second, but every other frame contains only half a screen, for an effective frame rate of 30fps. So if frame 1 is showing odd lines and frame 2 is showing even lines on a real tv , then isn't 30fps what you would see on the tv? Do emulators output like this to the lcd screen? Is the interlaced mode only on broadcast video, and video games actually output 60 full frames per second? The reason I ask, is that missing frames throw off your timing, so extra frames would probably do the same.

Chris
 
Squidge said:
US - 60fps, European - 50fps. Very few systems support interlacing.
So I guess the interlacing is just in the video signal coming from the tv station, and that the television itself is perfectly capable of 60fps non interlaced? Like the studio is putting out every other line blank, but if they broadcasted every line the television would display them?

Chris
 
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It is because the game systems use less than half of the full resolution allowed by NTSC. At full resolution (which is used by tv stations) it is interlaced.
 
Squidge said:
US - 60fps, European - 50fps. Very few systems support interlacing.
I think many old systems (SNES, Genesis/Megadrive, TG16/PCE) do support interlacing, just few/no games actually used it.
 
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Most consoles have a refresh rate of 50/60 screen refreshes per second. But that is not nessicarely the frame rate, you can say that 50/60 refreshrate is the maximum frame rate. AFAIK the frame rate for most of the console games of the 16-bit era is propably 15 FPS.
 
ledro said:
Most consoles have a refresh rate of 50/60 screen refreshes per second. But that is not nessicarely the frame rate, you can say that 50/60 refreshrate is the maximum frame rate. AFAIK the frame rate for most of the console games of the 16-bit era is propably 15 FPS.
So would 16 FPS be full speed emulation?

Chris
 
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christo930 said:
ledro said:
Most consoles have a refresh rate of 50/60 screen refreshes per second. But that is not nessicarely the frame rate, you can say that 50/60 refreshrate is the maximum frame rate. AFAIK the frame rate for most of the console games of the 16-bit era is propably 15 FPS.
So would 16 FPS be full speed emulation?

Chris


No, and the overall frame rate for the screen will never be something like 15fps (not for 8/16bit era or GBA games anyway). The animation rate, completely local to the object being animated, is probably going to be substantially lower than 60fps because that would involve a ton of very subtle frames to be drawn, but the motion of the sprites and scrolling of the screen will still be at this rate, and all of the objects onscreen will be animating at different intervals as well. Then throw in palette and raster effects.

There are also a few vector based games (ie, Vectorman) where the "animation rate" and the "motion rate" are the same thing. This game was actually advertised as having "60fps animation", or at least that's what I read in reviews.

A good visual indication would be some kind of difference filter that shows you what you'd miss by skipping frames, although I doubt anyone will go through the trouble of doing this just to make a point.
 
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True, but what we can say is that there are a couple of games where they have things like flashing lasers, etc, and if you run them at FS1, the laser becomes either invisible or permanently on, showing that you need to emulate 60 fps to get the full effects, even though the game elements themselves could be running much slower.

ie, exactly like Exophase has just said :)
 
Squidge said:
True, but what we can say is that there are a couple of games where they have things like flashing lasers, etc, and if you run them at FS1, the laser becomes either invisible or permanently on, showing that you need to emulate 60 fps to get the full effects, even though the game elements themselves could be running much slower.

ie, exactly like Exophase has just said :)
So then is it safe to say that *in most cases*, 30fps will be full speed, with an occasional animation sometimes needing the full 60fps?
 
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christo930 said:
Squidge said:
True, but what we can say is that there are a couple of games where they have things like flashing lasers, etc, and if you run them at FS1, the laser becomes either invisible or permanently on, showing that you need to emulate 60 fps to get the full effects, even though the game elements themselves could be running much slower.

ie, exactly like Exophase has just said :)
So then is it safe to say that *in most cases*, 30fps will be full speed, with an occasional animation sometimes needing the full 60fps?


That depends on the user. Some people are happy emulating at 25fps (or 30 in the USA), some find it to be too fragmented and too noticeable. I fall into the latter category, unfortunately, which is why I'm only really enjoying a few emulators at the moment (and others, conversely, are enjoying far more).

D.
 
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