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We want: An iPad video player with motion interpolation 

Take a trip to your local electronics store and walk down the TV aisle. As you do, consider the motion on each of the large flatscreen panels. If they are playing from the same source, usually a Blu-Ray disc, you will notice that there is a difference in the smoothness of each picture.

The effect that you are witnessing is called motion interpolation. Motion interpolation is a form of video processing in which intermediate animation frames are generated between existing ones, in an attempt to make animation more fluid. Many flat panel displays refresh at 120 Hz, so in an attempt to make the most of that fast refresh rate, many included some form digital enhancement to take the 24, 25 or 30 fps source video upto something closer to 120 Hz (120 fps). You may have heard of TruMotion, Intelligent Frame Creation, MotionFlow and ClearScan, these are all commercial names given by some of the more popular manufacturers to their versions of motion interpolation.

How does this apply to the iPad

The iPad IPS display refreshes at 65 Hz, possibly even higher. This means that the display could potentially playback a video with a 60 fps frame rate, thus opening the way for some bright developer to create an iPad video player app with a difference, that difference being motion interpolation, or whatever they decide to brand it as.

What is the point?

Faster frame rates will soon become the default for both home and cinema viewing. The human eye can easily perceive the difference between current film standard of 24 fps and 60 fps. 60 fps is about the threshold, anything higher is mostly wasted. Therefore is it reasonable to assume that both the TV and movie industries will naturally move towards 60 fps, a closer representation of reality. As they do, camera manufacturers will be expected to follow suite. Indeed, it is already possible to buy camcorders with 50 and 60 fps capture.

Though motion interpolation will never look quite as smooth as video that is actually shot at higher frame rates, it will make old and current movies look a lot nicer. To be fair, the effect isn't to everyones tastes, but that's okay, the developer should provide onscreen controls to increase or decrease the interpolation.

Is the iPad powerful enough?

In truth, I really don't know. I do know that the iPad is capable of playing 720p HD footage at 50fps, but the extra overhead of the interpolation process may restrict the feature to standard definition only.

So what say you developers, can this be done? There are now a whole host of video playback apps for the iPad, adding motion interpolation could give your app a differentiator. I've alerted a handful of developers to this article, it will be interesting to read their responses.

Further reading:

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Reader Comments (5)

I'm not sure you get the point of 24 fps . We have had the ability to film in 60fps (or 60hz) for quite awhile now and as as a filmmaker it is great for squeezing slow-motion into 24 frames. But also as a filmmaker what really getting indie and digital filmmaking going was finally being able to shoot video at 24fps. They call that the filmic look.

Motion interpolation is great for sports events making it feel more "real", but with movies (especially when it is drawing from material of 24 fps) it feels like you are watching it on mushrooms or some low grade LSD.

So as a movie buff I could care little about motion interpolation on my IPad. Maybe when a future iteration of the Ipad can pump out at 120Hz then sign me up as 24 Fps fits very nicely into 120hz (repeating each frame 5 times). It will be like watching it in the theater (or my 120hz TV playing bluray) .

September 13, 2010 | Unregistered CommenterMikeyGorman

i cant agree with you. according to apple official doc , ipad just support 30 fps video. i am sure about it.

October 3, 2010 | Unregistered Commenterhanse

I just wanted to notice : For watching movies, i hate this "motion interpolation" that my parents's new TV has. It makes all the movies look like if they were made with old video camera. I really can't physically explain why, but i really like this "filmic look" that MikeyGorman is talking about. And i feel this "filmic look" is even nicer on 35mm film cameras than digital ones.

November 4, 2010 | Unregistered CommenterAlexandre

Alexandre: I think it's a perception thing. As I mentioned above, reality is perceived at frame rates much higher than 24fps. Cinema will move closer to reality, it's inevitable. Then we'll look back at 24fps just as we do with black and white now and think how arty and quaint it is.

November 8, 2010 | Registered CommenteriPad Creative

I guess I'm fairly well qualified to answer this technically (I wrote 'Camera Boost', an app that does image enhancement and effects on live video on the iPad 2 - yes, at 30fps, 720p, not much different from what we need here).

Decoding the video, doing basic frame interpolation (simply blending 2 frames for a between-frame), and outputting at 60fps is no problem at all. Doing basic motion estimation for a more advanced version is probably possible. High quality, glitch-free motion-based interpolation? I'd be VERY impressed to see that. So maybe it's possible to improve the quality, but not all that much.

Should it be done? Honestly, I'd much rather see stuff recorded in 60fps in the first place. It's so much nicer to watch! Unlike some of the other posters here I find 24hz too low. I can see the screen flickering in the cinema, it's distracting and unpleasant, and when there's fast motion you get either excessive motion blur making it hard to see what's happening, or you get stuff jumping large distances across the screen each frame which is just awful. For slower moving scenes, it's not such a problem.

Has anyone tried 60fps video on the ipad? If that works, I'd really like to see a mac app instead - one that upconverts videos to 720p60 nicely and persuades itunes not to convert them before loading them onto the ipad.

April 28, 2011 | Unregistered CommenterChris / Interealtime

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