Reverse 3:2 pulldown, CineMotion, and how choppy video sucks

Just goes to show you that sometimes buying a toy you don’t fully understand can bite you.

Yesterday my wife and I settled in front of our new Sony Bravia TV (purchased through PowersellerNYC…awesome customer service and prices <end_shameless_plug>) and decided to rent a movie from the Xbox Live Video Store. The movie was Death at a Funeral, a very funny story about British shenanigans at a funeral. Since I only had 440 Microsoft points left in my bank (and this wasn’t really a made-for-hi-def experience), I decided to rent the 480p standard definition version (the 720p high definition version was 480 MS points, and I didn’t feel like re-upping my bank. Incidentally, Khidr and I will be doing an extensive gripefest about the M$ economy in another post, but on with the current story…).

As we began to watch this movie, there seemed to be a noticeable “skipping” that occurred with the video. Now, by way of background, my wife and I also had watched a movie that we had encoded and streamed from my local PC about a week ago, and a similar framerate issue was happening then. I had assumed it was because of my PC/network traffic/router/bad rip/something-else-to-do-with-streaming, and suffered through it, and didn’t really fret about the problem, as it never happened before with any other TV (all of which were, admittedly, not 1080p…more on that later). But a Video Store rental?! Nuh-uh. I can’t see paying for an experience this poor without trying to figure out what the problem is. Is it my Xbox 360? Is it 1080p? Is it my TV (hint: kinda)?

At first, I made the embarrassing mistake of calling Microsoft Xbox support to see if they could help me through the problem. After speaking with Justin, Neal, and Kevan (actual spellings), who insisted it was my router even though the Marketplace content was already downloaded (Justin), disconnected the call (Neal), and worried more about what file formats were supported and the fact that I moved to Texas than my problem (Kevan), I decided maybe I shouldn’t waste any more of my weekend and try to troubleshoot the issue on my own.

I had thought that perhaps the 360 had met its match with 1080p support (even though Call of Duty 4 has changed my religion in eye-blistering 60 frames-per-1080p-resolution-soaked second with nary a drop), so I dropped the resolution to 720p to see if the problem still occurred; stuttering still abounded. I scoured the Internet to find something that made even a bit of sense, and I came up with next to nothing, other than a random post on what I believe was the TeamXbox forums from back in early 2006 about 3:2 pulldown. I was skeptical about it, so I continued about my evening, and eventually just went to sleep to tackle the problem another day.

Now, before I continue, I’m going to link to two well-written articles about 3:2 pulldown as it relates to newer televisions. The concept of 3:2 pulldown is pretty interesting, and if you are planning to get a new TV at any point, you might want to have this information stored in your brain.

THIS ONE

AND THIS ONE

The following morning, I figured that messing with my TV settings couldn’t really hurt. As the concept of 3:2 pulldown bounced around in my brain (along with lots of coffee-flavored stimulus), I remembered that my new TV had a function called CineMotion. While the manual isn’t terribly helpful, it does offer this:

CineMotion: Select Auto 1 or Auto 2 to automatically detect film content and apply a reverse 3-2 pulldown process. Moving pictures will appear cleaner and more natural looking. Select Off to disable the detection.

Based on what little I knew about 3:2 pulldown, and what is “film” vs. “video”, I wasn’t terribly sure what framerate the video on the 360 happened to be (and I wasn’t too sure about all this fancy voodoo magic these new-fangled TVs these days are whippin’ up), so I figured perhaps the reverse 3:2 pulldown was causing issues for files that had already been captured (or at least were being delivered) at the appropriate framerate (24fps vs. the approximate 30fps that reverse 3:2 pulldown should fix). I decided to disable it to see if it did the trick, and it did! Now, all of the video files play pristinely and without stuttering. What I think might be the key (just spitballin’ here…) is that the actual frames created to produce the 30fps onscreen might not be derived in the same manner as the the typical frame expansion during the telecine transfer. It might also be that the 360 handles the 3:2 pulldown duties, making further processing redundant. In any case, I’m happy to report that I can watch movies without the distracting stuttering that I endured recently.

Now, I don’t pretend to know the intimate details of all things 3:2 (I have read a few more articles that are not quite as forgiving in their attempt to explain such things, so I haven’t linked to them), or really the exact reason why this caused the painful problems that it did (it’s tough to see at what framerates the content in question is being delivered), but this was an obscure-enough fix that I figured it was important to share with others. I had NO IDEA just settling in to watch a movie would be this involved.

The moral to all of this is to check out your TV settings, folks! I’m sure there are tons of other things in the settings I’m going to have to learn about and tweak (per the CNET review, this TV has an intimidating amount of settings in the menu system), so I’ll be sure to pass on any other hard knocks I pick up along the way. Any interesting tech stories you’d like to share?

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