How to eliminate juddering in panning shots?

Question

How to eliminate juddering in panning shots?

Hi everybody,

here's my problem -

My Sony camcorder records m2ts files in 1080/50i (or 1080/25i as Apple/FCPX calls it). To achieve maximum compatibility to Apple TV 4, I'd like to export my film as m4v in 1080/30p. But when I do, I see some annoying juddering during pan shots that drives me crazy and spoils every viewing experience. Those judders are visible on my iMac (when watching the film with QT or VLC or similar) as well as on my Apple TV via iTunes.

Now here's the thing - if I watch the original m2ts files using VLC, I still see the same juddering. BUT with "deinterlacing" set to on and "deinterlacing mode" set to "bob" (both in VLC), those judders are immediately gone and the panning quality is brilliant!

Now, how do I achieve this quality using FCPX/Compressor 4 on 1080/30p ?

I have already tried many many settings within FCPX and Compressor. Besides, I tried to deinterlace my original m2ts files using Handbrake, but to no avail so far, my panning shots still look jerky and juddery. So either I'm not able to find the proper settings or it's simply not possible with FCPX/Compressor - which I can't believe. VLC can do it while viewing (as described above), so FCPX should be able to achieve this as well while encoding, right?

Can anybody help me or point me in the right direction....?

Thank you all!

Best,

Gero

iMac with Retina 5K display, OS X El Capitan (10.11.4)

Posted on Jul 4, 2016 1:31 AM

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Answer 1

Tom Wolsky

Level 10

152,816 points

Jul 4, 2016 2:56 AM in response to gerofromronnenberg

WWhy 30p? Are you saying AppleTV doesn't support 25p?

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Answer 2

Jul 4, 2016 3:04 AM in response to Tom Wolsky

...it's just that I read that e.g. iTunes needs 30p for the best viewing performance of self-made videos (via m4v files) on Apple TV... is this wrong? Would 25p work? And if yes, how would I best de-interlace my video and convert it from 25i to 25p using FCPX? And would that juddering be eliminated if I did?

Thanks!

Gero

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Answer 3

Tom Wolsky

Level 10

152,816 points

Jul 4, 2016 3:07 AM in response to gerofromronnenberg

SSwitch off background rendering and edit in a 25p project.

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Answer 4

Jul 4, 2016 3:20 AM in response to Tom Wolsky

...will try that and report back here! Thanks Tom!

Best,

Gero

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Answer 5

Jul 4, 2016 3:23 AM in response to gerofromronnenberg

Panning is hard to do well.

Plus, you are facing two compounding problems: first, you are shooting interlaced; second, you are adding extra frames by going up from 25 to 30. This means the software has to add one extra frame for every 5 frames.

Both issues collude to make it difficult to get a decent result. I can only suggest you try different options for Rate Conform in the Inspector and see if you get a better result with Frame Blending or Optical Flow.

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Answer 6

Jul 4, 2016 3:26 AM in response to Luis Sequeira1

...thanks, will look into this too!

Best,

Gero

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Answer 7

Jul 4, 2016 4:28 AM in response to gerofromronnenberg

1. If your camera shoots 25fps (1080/50i) you should edit as 25fps (either interlaced or progressive).

2. It is very difficult to get smooth panning shots (of a static subject) as you have to pan incredibly slowly . . . maybe taking 10 seconds to move the width of the frame. This of course can lead to some extremely long and boring shots! The film industry has been aware of this for over a century and use various tricks when shooting to minimise the camera movement . . . such as shooting diagonally on a moving subject etc. and simply avoiding panning altogether where possible.

Panning on a moving subject is quite different as you are looking at the subject (hopefully) and even though the background is jittering like a dervish, your brain will be ignoring it.

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Answer 8

Jul 4, 2016 4:41 AM in response to Ian R. Brown

Hi Ian,

thanks for your advice!

About your 2. point -

I am generally aware of this problem. But the thing is (as described in my initial post) that if I view my original files in VLC using the two de-interlacing settings I mentioned, then all panning shots look great, with panning smooth as butter! This tells me somehow that it is actually possible to get satisfying panning results out of a given file. That said, I will give exporting in 25i/25p a try tonight, maybe that will already solve my problem! In any case, I will report back here!

Thanks again!

Best,

Gero

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Answer 9

Jul 6, 2016 11:57 AM in response to gerofromronnenberg

A setting in your TV menu might help smooth out the panning shots.

Most modern TVs have a Motion Interpolation function which smooths movement.

The TV manufacturers give this function their own name; the following is from wiki...

This function is normally found in the menu settings for Picture but may vary.

See if your TV menu is set for ON for this function.

Be aware that some TVs can have menu settings set up for each input.

For example you can have a function set for TV but not for say a Blu-ray player connected via HDMI.

In other words you have to set the menu for the specific input you require, in your case the Apple TV input ( HDMI ?)

Don't assume that if it is set for input HDMI 1 that it is also set for HDMI 2

This may not smooth the panning for your video where you have gone from 25 to 30 fps ( a bridge too far perhaps) but may help

for purely 25 fps material.

As a matter of interest I have never been able to get smooth panning when using progressive except by turning ON the motion interpolation on my Samsung TV.

I can get smooth panning by using interlaced without having to turn on motion interpolation.

Video juddering or strobe when panning

The majority probably don't see any judder because the motion interpolation is set to ON when shipped from factory.

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Answer 10

Jul 7, 2016 12:31 AM in response to gerofromronnenberg

aside the many excellent suggestions given allready:

when you dig really deep into cinematography, you stumble upon terms like Angle Velocity ... lots of theory, lots of math, even calculators are avail

http://www.staminteractive.com/distributors/calc_5.html

in short:

apply motion blur

... by long shutter-speed on recording or in post (link to a free plugin ...)

http://www.staminteractive.com/distributors/calc_5.html

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Answer 11

Jul 7, 2016 1:55 AM in response to Karsten Schlüter

Hey,

thanks everybody for your hints, but the solution was easier than expected. I found out that the Apple TV can handle 50p video just as easily as 30p video after all. So all I had to do was setting up a FCPX project with 1080/25i (as my original files are in 25i too, as mentioned), copy the clips and transitions from the original timeline of the old 30p project and then send the new project to Compressor. There, I just switched to 50p in video settings - and that was it! Compressor does the rest on its own, it creates progressive frames from the interlaced original frames, thus doubling the frame rate.

The result are silk-smooth panning shots, just as I wanted them to be. And as I said, Apple TV handles these exactly the way that 30p video is handled, even though the "Apple TV" compatibility list entry in Compressor is greyed out when switching from 30p to 50p.

Thanks again everybody, I hope my experiences can help others too!

Best,

Gero

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