Converting 4K@30fps footage into 1080@60fps

Bletch

Bletch

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Hi guys.
I was in India last year with my Dji Osmo, I think I made a mistake of filming some scenic rooftop shots in 4k at 30fps. I wish I hadn't as some of the footage I shot from a moving tuk tuk in 4k at 30fps was headache inducing, even walking by people, I didn't like what I shot. I wish I had stuck to 1080@60fps.

This year when I go back to India, the plan is to shoot everything in 1080@60fps. Will I still be able to combine some of the 4k stuff knocked down to 1080 & converted to 60fps? I just need a few seconds here and there - the rooftop shots I have are either slow pans or just static shots, nothing fast moving. I can't reshoot from the same rooftops - expensive hotels last year! :)

Can someone just confirm turning 30fps footage into 60fps footage does not make the final footage run twice as fast, okay stupid question I know, so any other defects caused by doing this?

Thanks!
 
You can't convert from low to high.
The missing information between frames is still missing.

You can upscale 1080 to 4k which isn't true 4k (well 4k isn't either but I won't get in to that) and then run those 60fps still.

If you have software that can guess the frame between frames by making a calculated judgement of how it would differ between frame 1 and frame 2 then you could look to produce 60fps but that just doesn't happen.

Fps is the one thing you can bump up, only down.
 
You can't just stick 30fps into a 60fps timeline/project. It will need upsampled to 60fps. Many programs will do a rough job of upsampling if chosen, and it may be good enough (usually you get a "mismatch" dialogue and it asks if you want it converted to match). But there are other options that do a lot better job of upsampling if needed.
 
Converting from 4k to HD is slightly involved as they are different aspect ratios - 4096x2160 to 1920x1080. You have to choice of cropping to UHD1 (3840x2160) then down converting, having blanking bars or using the wrong aspect ratio. Of them, the first is mathematically easiest so looks the best.

To go from 30 to 60 you can repeat frames, use a simple filter which averages the 2 adjacent frames or use a complex motion compensated frame interpolation (smooth flow, trueflow, etc.). With 1 you know what you're getting, 2 you know what artefact you'll get, 3 looks good until it goes wrong, then it goes very wrong indeed.
 
Hey guys. Thanks for your input. I'm going to try to cut out the parts of the 4k footage I want, convert it to 1080@60fps somehow and then add it to my other footage when I'm ready. If it doesn't work, it's not the end of the world :)

@mat. Generally speaking, I'd personally rather watch stuff shot at 60fps on the tube and as I said in my first post, I wasn't really happy with some of the footage I did at 4k@30fps, I wanted to add it to stuff I've shot/will shoot in October.

Cheers
 
Hi st599.
Are you talking about the light flickering I was getting when shooting at night sometimes (which is caused by all the various different types of lighting I came across)? The Osmo has an anti-flicker setting, you can switch between 50-60hz but it wasn't really much use. Should I have been shooting at 50fps to get rid of all the flickering?
 
You can convert a 30p 4K timeline to 1080 60p in Apples Final Cut Pro. You simply start a new project with the 60p 1080p properties. Apple then does all the work for you Only problem I found was that I had to export it as a .mxf file via Compressor to maintain the 60p frame rate. Thus I had to use VLC to view the output. All the other output options defaulted to 30p.
 
Bletch said:
Hi st599.
Are you talking about the light flickering I was getting when shooting at night sometimes (which is caused by all the various different types of lighting I came across)? The Osmo has an anti-flicker setting, you can switch between 50-60hz but it wasn't really much use. Should I have been shooting at 50fps to get rid of all the flickering?
Click to expand...
Yes, if you shot at 50, you'd have caught the same amount of the mains sine wave in each frame, at 59.94 you get a different amount in each.
 
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