24 fps animation

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psycopathicteen
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24 fps animation

Post by psycopathicteen » Sat Jan 11, 2014 1:59 pm

Are there any 8-bit or 16-bit games that used the standard animated film frame rate?

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koitsu
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Re: 24 fps animation

Post by koitsu » Sat Jan 11, 2014 2:11 pm

Here's my terse response: why would you want this?

And my more detailed response: I think what you're really asking is: has anyone tried doing 3:2 pulldown (or alternately 2:3) on the NES... which I'm not sure is even possible. There's no real "conversion" going on (i.e. source vs. output), so I think you'd be limited to this method:

Given that NMI is usually tied to VBlank (called 60 times a second (NTSC) or 50 times a second (PAL)), achieving exactly 24fps would have to be simulated by keeping track of every time VBlank got called + do some math to determine if you should update data (nametables, etc.) for the upcoming screen refresh/draw or choose to do nothing (for that frame).

What you'd end up with visually on-screen would be a sort of stuttering or a sort of telecline judder. The stuttering would look different on NTSC than PAL too (60/24 = 2.50 vs. 50/24 = 2.08). The visual results I imagine would look like crap.

And technically it's 23.976fps, but I say that to keep tepples happy. ;)

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Re: 24 fps animation

Post by Joe » Sat Jan 11, 2014 2:36 pm

koitsu wrote:And technically it's 23.976fps, but I say that to keep tepples happy. ;)
You'd still be short by about two frames in 24 hours if you use 23.976 instead of 24000/1001. :P

Although if you did pulldown on a NTSC NES/FC, you'd get something more like 24.04 fps, which is still pretty close to film (and would still have the same judder as any other 24fps content pulled down to NTSC compatibility).

It wouldn't work well on PAL, though - you'd either need to do 3:2:2:2:2:2:2:2:2:2:2:2 pulldown or speed it up to approximately 25fps.

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Re: 24 fps animation

Post by tepples » Sat Jan 11, 2014 2:38 pm

koitsu wrote:Here's my terse response: why would you want this?
Especially when movements from one cel to the next in 8-bit games are small enough that anything more than the 12 fps cartoon standard wouldn't provide a noticeable enough smoothness benefit to justify its ROM cost. Animate at 12.02 fps (5 field pulldown) on NTSC or 12.50 fps (4 field pulldown) on PAL and you should be fine.

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tokumaru
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Re: 24 fps animation

Post by tokumaru » Sat Jan 11, 2014 5:16 pm

koitsu wrote:And technically it's 23.976fps, but I say that to keep tepples happy. ;)
AFAIK, actual film runs at 24fps, it becomes 23.976 only when converted to video. But you also have to consider that the NES doesn't output video at 60fps either, it's slightly faster than that.

I don't see any real complexity in animating at film rate on the NES, you just need a fixed-point accumulator being updated every frame to indicate when it's time to move on to the next frame. I don't think the stutter would be too noticeable either, but we'd need some kind of test to verify that.

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Re: 24 fps animation

Post by Shiru » Sun Jan 12, 2014 3:58 am

It may be useful for cutscenes in retro style, like, sepia palette, and not that smooth object movements.

psycopathicteen
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Re: 24 fps animation

Post by psycopathicteen » Sun Jan 12, 2014 1:36 pm

I meant sprite cell animation frame rate.

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Re: 24 fps animation

Post by Shiru » Sun Jan 12, 2014 2:20 pm

It does seem that standard 'fluid' animation on NES (Moon Crystal, for example) uses the on fours, i.e. 15 FPS.

It should be noted that 24 FPS is not really a standard animated film rate. The film itself runs at 24 FPS, but the cel changes rarely gets that fluid, for the most part it is on twos or threes, i.e. 12 or 8 cel changes per second.

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tokumaru
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Re: 24 fps animation

Post by tokumaru » Sun Jan 12, 2014 3:20 pm

Shiru wrote:It should be noted that 24 FPS is not really a standard animated film rate. The film itself runs at 24 FPS, but the cel changes rarely gets that fluid, for the most part it is on twos or threes, i.e. 12 or 8 cel changes per second.
Yes, but they often try to "fake" smoother animation, by updating different actors in alternating frames or displacing static pictures, so that something always changes from frame to frame.

I've used a similar trick to make palette fades on the NES look smoother: instead decrementing the brightness of all colors at once, I decremented the brightness of the darkest colors only, making them black. Then, on the next frame, I made the second darkest colors darker. Then the third darkest colors, and finally the brightest colors. This means it took 4 frames to darken the whole palette by 1 step (a regular fading sequence would've already ended in this many frames). Then I handled the remaining 3 brightness levels, then 2, then the last one. In the end, instead of a 4-step fade sequence you get a 10 step one (4 + 3 + 2 + 1).

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rainwarrior
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Re: 24 fps animation

Post by rainwarrior » Sun Jan 12, 2014 4:38 pm

Maybe check out FMV games if you're looking for something that is likely to use 24fps. Dragon's Lair on Sega CD maybe? What was that FMV car driving game?

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tokumaru
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Re: 24 fps animation

Post by tokumaru » Sun Jan 12, 2014 4:46 pm

Most PlayStation 1 FMVs I checked back then were 15fps. I'm willing to bet that's what SEGA used most of the time too.

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rainwarrior
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Re: 24 fps animation

Post by rainwarrior » Sun Jan 12, 2014 4:56 pm

If the FMV was made for the game I'd expect them to use a sensible division of 60, yeah. I'm more suggesting looking for cheaply/hasilty made ports maybe... though honestly I would be surprised if anything used 24fps. I'm just trying to think of the most likely place if it does exist.

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Re: 24 fps animation

Post by tomaitheous » Sun Jan 12, 2014 9:30 pm

tokumaru wrote:
Shiru wrote:It should be noted that 24 FPS is not really a standard animated film rate. The film itself runs at 24 FPS, but the cel changes rarely gets that fluid, for the most part it is on twos or threes, i.e. 12 or 8 cel changes per second.
Yes, but they often try to "fake" smoother animation, by updating different actors in alternating frames or displacing static pictures, so that something always changes from frame to frame.

I've used a similar trick to make palette fades on the NES look smoother: instead decrementing the brightness of all colors at once, I decremented the brightness of the darkest colors only, making them black. Then, on the next frame, I made the second darkest colors darker. Then the third darkest colors, and finally the brightest colors. This means it took 4 frames to darken the whole palette by 1 step (a regular fading sequence would've already ended in this many frames). Then I handled the remaining 3 brightness levels, then 2, then the last one. In the end, instead of a 4-step fade sequence you get a 10 step one (4 + 3 + 2 + 1).
That is pretty clever :D (the fade trick)

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Re: 24 fps animation

Post by tomaitheous » Sun Jan 12, 2014 9:31 pm

rainwarrior wrote:Maybe check out FMV games if you're looking for something that is likely to use 24fps. Dragon's Lair on Sega CD maybe? What was that FMV car driving game?
Road Avenger, and it's like 8fps or lower.

psycopathicteen
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Re: 24 fps animation

Post by psycopathicteen » Fri Jan 17, 2014 10:15 am

tomaitheous wrote:
rainwarrior wrote:Maybe check out FMV games if you're looking for something that is likely to use 24fps. Dragon's Lair on Sega CD maybe? What was that FMV car driving game?
Road Avenger, and it's like 8fps or lower.
I remember somebody on Sega-16 trying to convince me that Street Fighter 2 was animated at 24fps, when it was so obvious that it wasn't.

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