For the longest time, one of my complaints with this software was that while the resolution of the shows was always excellent, the playback of the shows was rough and felt choppy. I chalked this up to underpowered equipment for the longest time, but recently I discovered that the majority of my cards are played at a refresh rate of only 25 hz, while some of my favorite cards are played at 30 hz. What I would like to know is, if these shows are being filmed with 4K cameras, why are they still played back to us at such low refresh rates?

I would guess its a trade-off between file size, CPU load and quality. A higher frame rate would require larger files and more processing. I've seen that playing multiple cards in small mode imposed considerable load on my CPU.

I definitely see your point there. It would be great if the older cards that get updates every now and then could be updated with higher refresh rates though, because at 720p@25hz isn't the most spectacular look.

Doing an update would depend a lot on the original material. If the original records were at a higher frame rate, that would be great. If the original records were at 25 FPS, high quality post-production could make what we see look a bit better, but with more effort and a smaller improvement.

do a littler research in to Video and Cinema..

These are industry standards for Cinematic Video.
the 24 / 25 Fps
and the 30 Fps ( 29.97)

I know from experiance just how much better the girls look with motion interpolation added to them to make them 60/120fps and have suggested previously that they create a interpolator or allow smooth video project to hook into the player, it gained zero traction. Motion interpolation doesn't even take that much power, even cheap tv's can do it with full 4k video(admitadly with some glitching).

@Z22

....have suggested previously that they create a interpolator or allow smooth video project to hook into the player...

Now I'm ***** about where/if there's interpolation happening on iS files.

I thought that the player used the cpu to size the frame at 30fps, which is the rate of the movie file, and the graphics card interpolates to 60fps, to fire it down the DP cable to the TV. Is that correct, or does the TV do the interpolation? Maybe I'm just imagining that there is any interpolation happening at all, but even old cards look pretty smooth to me (even if 720p is a bit fuzzy).

And, if it's the TV/monitor that does the interpolation, how can the iS player make that work? I thought that modern TVs took whatever they were given and automatically did the best they could with it (i.e. interpolated to the max rate of the screen).

Even if the player interpolates to 120fps as you suggest, isn't the limit of a DP cable 60fps? I really don't understand what's happening and where, let alone what Totem could do to make it better.

Istripper plays the same frame twice to get 60fps(or more depending on your refresh rate of your display, current max i have seen is 240hz), that frame doubling is not what i am talking about.

Roughy... Motion interpolation is the creation of a totally new frame between 2 existing frames to smooth out the motion. There are several methods but the simpiest is a pyramid search which progressivly scans the 2 images to find similar blocks and records their different position as a motion flow map, that motion map is used to create the new inbetween frame.

My tv(and most newish tv's) can do this without the pc having to do anything but many people use monitors which don't have this feature so it would benefit them. From my experiance the girls look way better if i have smooth motion on than if it's off

(dp 1.4 is capable of 120hz in 4k, hdmi 2.0 60hz in 4k, hdmi 2.1 120hz in 4k)

Original material has been recorded either at 25FPS or 30FPS, we publish as many FPS as we recorded.
We don't record in 4K at 60FPS because that would be a drop in the image quality (the recorder / encoder has a bandwidth limit and it would be a trade for image quality).
I don't think we could interpolate images in real time without using too much CPU. TVs doing real time interpolation are using their own hardware and there is no CPU cost for the source.
As to add interpolated frames in post production, I'm not sure having files twice the size, plus having to store all files in 30FPS and 60FPS would have a good ratio trouble/benefits.

Thanks for coming in on this thread Rex, I agree that adding extra frames in post would be a bad idea and it wasn't what i was suggesting. I do think that it could be done on the gpu for a resonable cost as far as i can tell, been looking into it myself but my limited shader knowlage is holding me back atm.

Many thanks for the excellent explanations of the interpolation business.

It sounds like people who have TVs capable of interpolation don't need any extra software. For those with older monitors, maybe a routine in the gpu would help. But my old monitor ran VGA and, although some may have HDMI, aren't those interfaces limited to 30fps anyway? When I upgraded the monitor I also had to change the gpu, which was max'd out at 30fps, so an interpolation programme might have ***** it completely.

I think, @Luckysguy, you got an answer to your question, but the choppy image problem might be the monitor. I just ran a 720p on mine and it was completely smooth - the monitor seemingly interpolating happily. What monitor and interface are you using?

It depends on which version of hdmi but hdmi 2.0 can do 4k @60hz and 1080p @120hz happily. I have seen older crt vga monitors that could do 75hz in 1600 x 1200 so there isn't really a 30hz limit on display connections. You're probably correct about it melting your old gpu, it must have been quite an age to have a vga port on the back.