#motion interpolation

[21tailsofwoe]

kenhina kofi request by @i-just-really-love-sakura !!

[ youtube link ]

[21tailsofwoe]

People ask me a lot about how i do the “slow motion 3D” thing in my videos. It turns this:

into this:

This “slow motion 3D” effect is actually called motion interpolation. Basically, the process involves adding additional frames in-between existing frames and gives a smoother look to videos. 

There are different softwares that can help you with motion interpolation. “Twixtor” is a plugin that you can install in video editing softwares like After Effects, Vegas Pro, HitFilm, Premiere Pro, and whatnot. This is not a sponsored post, I got mine illegally.

Twixtor got pretty popular with AMV makers after the first motion interpolated AMV, “Into The Labyrinth”, descended from the heavens in 2014. Ever since then, AMVs and anime Vines haven’t been the same. Creators have essentially entered God Mode with Twixtor. I can’t hope to reach that level with my puny little laptop, but I can have fun with it! And if you like making AMVs, maybe you can give it a try too! You’ll find a lot of tutorials online that explain it pretty well.

Also, while you’re here, check out the AMV that makes me the person that I am today.

[21tailsofwoe]

short gintama edit for kc!

[awfulhorrid]

Look, I'm not saying people that upload movie clips to YouTube with that "motion interpolation" BS should have their fingers broken so they can't do it again, but I do think we should at least consider it. At the very least they should be slapped hard and made to atone for it.

[ghostfaceg]

[objectivelysmart]

And now for something completely different: motion interpolation in mpv

Alright, this one is not going to be about programming, but hey – when was the last time I actually wrote anything about programming anyway, right? It's a crying shame – or at least I'd like to think it is – but programming during the day exhausts one so much that I'd have to be a supernatural being to be in a mood to write about programming in the evening, too. I mean, more supernatural than I already am, of course.

It doesn't mean it's not going to be about an interesting topic, however. The topic is motion interpolation and without going into all of the boring technical details, I'd rather just tell you what is it and why you can't live without it in 2015. You're probably well aware of the fact that most movies and TV series are still shot in 24 frames per second (which is far, far away from a high enough number) and the illusion of motion is not accomplished by rapid displaying of different images as much as it is done by utilizing an effect known as motion blur. But what would happen if we took away the motion blur and increased the number of frames per second instead?

Well, we may never know that, at least not in the foreseeable future, because getting rid of motion blur in already recorded movies would be… somewhat complicated to say the least, but we can at least artificially increase the number of frames per second. Okay, but hold on – if the missing frames are not present in the source material, where would they come from? From the aforementioned interpolation, of course!

Now, let's set up a video player to perform the real-time interpolation for you. I'll be using mpv in this tutorial as that's objectively the best video player for OS X out there (stop arguing, you're just being ridiculous with your VLC) but it might be possible to accomplish similar results with other players. But it probably isn't, ha!

We'll need to get some additional tools first – namely VapourSynth to filter the video just before mpv plays it for you and MVTools to provide the best motion interpolation filters for VapourSynth. Since we need mpv to support VapourSynth, we can't use Coalgirls' pre-built binary – we'll have to go back to the square one and compile our own binary from source. Open Terminal.app and if you don't use the Homebrew package manager already, please go sit in the corner and feel an appropriate level of embarassment. When you're back, install Homebrew with the following command:

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Add the mpv repository:

brew tap mpv-player/mpv

And install VapourSynth and MVTools1:

brew install vapoursynth brew install --HEAD mvtools

Now compile mpv with the VapourSynth support and create symlink to the /Applications directory:

brew install mpv --with-vapoursynth brew linkapps mpv

Set up autoload of the MVTools library:

cd /usr/local/Cellar/vapoursynth/26/lib/vapoursynth ln -s /usr/local/Cellar/mvtools/HEAD/lib/libmvtools.dylib .

And create VapourSynth configuration script in your ~/.mpv directory (create the directory with mkdir ~/.mpv if it doesn't exist). I called mine mvtools.vpy and it looks like this:

import vapoursynth as vs core = vs.get_core() clip = video_in if not (clip.width > 1920 or clip.height > 1080 or container_fps > 59): clip = core.std.AssumeFPS(clip, fpsnum = int(container_fps * 1e8), fpsden = int(1e8)) sup = core.mv.Super(clip, pel=2, hpad=0, vpad=0) bvec = core.mv.Analyse(sup, blksize=16, isb=True, chroma=True, search=3, searchparam=1) fvec = core.mv.Analyse(sup, blksize=16, isb=False, chroma=True, search=3, searchparam=1) clip = core.mv.BlockFPS(clip, sup, bvec, fvec, num=60000, den=1001, mode=3, thscd2=12) clip.set_output()

The indentation is important because… reasons. Now edit your mpv configuration file, it should reside in the ~/.config/mpv/ directory under the mpv.conf name. Make it look like this:

vo=opengl-hq vf=format=yuv420p,vapoursynth=~/.mpv/mvtools.vpy

If you've placed the MVTools script to another location, you might want to reflect that change in the configuration file as well. Just a hint. Well, at this point you should be good to go, really – that is, unless I forgot some step along the way (let me know in the comments if that's the case). Feel free to set up mpv as your default video player as well – actually forget that, chances are it's your video player to go for a long time, right?

I'll leave with a few quick notes that I gathered during my first two days of usage:

yes, you can use it with Popcorn-Time, but you might want to add the idle=yes and keep-open=always options into your mpv configuration file;

no, it's not one hundred percent stable, you may expect issues in particular whenever a different source file is loaded within the same mkv container;

yes, you can use it to play YouTube video files as well, just brew install youtube-dl and brew reinstall ffmpeg --with-openssl; also consider adding ytdl-format=299+bestaudio/137+bestaudio/298+bestaudio/22/135+bestaudio/18/best to your mpv config file;

no, I did not report the aforementioned bug, please don't hit me reported, pull request not accepted as of yet;

yes, you could even be able to use it with Crunchyroll and other services, if you installed youtube-dl with the --with-rtmpdump option; and finally

no, you won't be able to watch any video with measly 24 FPS after this anymore, it would just feel weird.

If either of these commands fails because of a MD5/SHA1 checksum problem, I'd assume that's a temporary problem that's going to be solved in a very near future. If you don't want to wait, however, poke me in the comments for a quick 'n dirty workaround. ↩︎

[imchill]

Watching Dredd with motion interpolation enabled is like a religious experience. 

[checkthegate-blog]

Rant of the Day: Why I Hate Motionflow

For a long time, I thought I would never have to complain about Motionflow (also known as Motion Interpolation). I assumed the problem would work itself out. By that, I mean, I figured others would notice how truly awful Motionflow makes a cinematic image (anything shot at 24fps) look and would naturally begin turning the option OFF on their respective HDTV's. I was wrong. I guess I gave people too much credit.

Example: I walked into a friend's apartment recently. I had always valued this specific friends opinion on art and films in general, so, when I noticed that Motionflow was enabled on his television during a viewing of 'T2: Judgement Day', I said something along the lines of "ugghhh, you know you're desecrating that film right now, right?" His reply was something along the lines of "I have kinda gotten used to it." This disturbed me profoundly. Motionflow is not something one should "get used to". It's just as much of a slight to a filmmakers vision as pan and scan. It's NOT what the filmmaker intended you to see. Motion Interpolation creates frames that were never there. It manipulates the picture in an attempt to help the television not have judder (or visual artifacting) during faster moving sequences (like a Michael Bay action scene). As the diagram above displays, it's adding a frame that is not there to begin with. This kind of manipulation makes the picture seem to move almost unnaturally. I, personally, find that I cannot concentrate on anything but nastiness of the Motionflow when it's enabled. Yet, constantly I enter households that have their 60 inch HDTV set in this mode (Note: it comes set that way out of the box).

Some of this I write off to the general public not doing their research, but the other half has to be attributed to the likes of the 'Best Buys' of the world. Mainly, because they push this crap. Every TV on display in 'Best Buy' is set with Motionflow turned on. The crappy retailers out there actually push Motionflow as a sort of "hyper-real" experience. This angers me in ways I can barely describe. By changing the frame rate of the picture, you are literally changing the entire "feel" of the film/TV show. Quite frankly, the "video" feel of Motionflow feels like the equivalent of a really well filmed home video. It completely kills the cinematic experience. And isn't that why we purchase large HDTV's in the first place, for that "cinematic experience"?  I urge everyone with an HDTV to please turn the function off and view the films and television shows you watch in the proper format. It will prevent me from coming off as a pompous asshole when I enter people's households and immediately start finicking with their remote controls (yes, I have done that, and a very many have rolled their eyes at me).

**Note: Although I have spent this rant completely tearing down Motion Interpolation, it does serve a purpose, and that is in the gaming community. It greatly enhances the use of a PS3 or XBox360. Yet, since you typically run such consoles under a different HDMI input in your television, it's simple to keep the Motionflow on for gaming, and not for viewing television and films.