Apple TV - Video Stutter.

Discussion in 'Apple TV and Home Theater' started by BlackMangoTree, Oct 5, 2010.

  1. macrumors 6502a

    Sep 30, 2010
    This has been discussed in other threads, i thought i would start it's own thread in hope it gets more attention and we can all work together to get some solution.

    Instead of me explaining the issue i'll just post what hipnetic has said.

    Just registered so that I could reply to this thread. I did some Googling on stuttering and found this thread. I've reported in the Handbrake forums and in the following Apple support forum thread that I'm having problems even with 720p content:

    Note: There are several of us reporting the problem in that thread.

    To summarize, the problem is not related to the network. The movie has been fully loaded to the Apple TV's buffer. For those who do not own a new Apple TV, when the status bar is all white, the movie is fully loaded to the buffer. When it is only partially loaded to the buffer, the white portion of the status bar is how much has been loaded to the buffer, and the gray portion behind it, has not.

    The interesting thing is that it appears that the stutter/judder/dropped frames are actually *more* frequent when the movie is *fully* loaded to the buffer. That seems counterintuitive, but there you go. One person experiencing this problem theorized that perhaps the Apple TV is getting ambitious once it's loaded the movie to the buffer and is doing some sort of background task.

    In any case, the movie that I'm using to test with is Monsters vs Aliens. The opening scene (right after the film stock melts away) shows some part of the universe, with the camera panning through the asteroid rings around a planet, then centering the camera on another planet, which then explodes. That panning sequence is good for noticing stutter/judder. I have a few different flavors of this movie converted via Handbrake. All play perfectly smoothly on my Acer Revo nettop running Windows 7 and XBMC. These 720p files also appear to play perfectly smoothly on my iPhone 4 (but the screen is so small that it's possible that there's a glitch that I'm just not seeing). One person indicated that they did not see the problem on their iPad, which is important because one theory/concern of mine is that the Apple TV's 256 MB of RAM could be insufficient (the iPhone 4 has 512MB). But as I don't have access to an iPad I can't confirm this first-hand.

    My hope is to keep that thread towards the top of the Apple support forums and that they'll issue a firmware fix (assuming they
    *can* fix it).
    End Quote

    My experience has been, Video i have encoded for the original Apple TV using Handbrake when played back on the new Apple TV once the file is fully buffered onto the Apple TV it will stutter all over the place.

    New encodes i have done using the latest nightly build of Handbrake using the High Profile preset playback perfect with no stuttering.

    I am not 100% sure but i suspect this could be an issue with our TV's something to do with the fps and hz.

    Anyone experiencing similar issues please post your findings maybe we can put a finger on what is causing this issue.
  2. thread starter macrumors 6502a

    Sep 30, 2010
    Has anyone seen this issue with iTunes movie rentals ?

    hipnetic, to answer your question, I been using the lastest nightly build SVN3570 64 bit OS X version.

    I select the high profile preset i set the the audio one aac one ac3 track, the RF i use is 18, i turn all filters off and set the resolution to 1280 anamorphic set to none.

    Some people have reported this issue with the iTunes rentals as well so i don't think it has anything to do with handbrake.
  3. macrumors 6502a

    Oct 5, 2010
    Just to clarify, you said that you are *NOT* seeing this problem with the nightly builds (set as you've indicated), but you *ARE* seeing it with older encodes (using the profile setting for compatibility with the older Apple TV), correct?
  4. thread starter macrumors 6502a

    Sep 30, 2010
    So far with the latest nightly i have not see the issue using High Profile.

    All the videos i have seen the problem with where done with previous nightlies using the Apple TV preset
  5. macrumors 6502a

    Oct 5, 2010
    OK, so you're using *literally* the latest nightly build (as of Oct 5)? Thanks, I'll give that a try and will report back.
  6. macrumors regular

    Feb 1, 2010
    Good thread. Thanks BlackMangoTree.

    So is it safe to assume that we all should use the nightly build and the "High Profile" preset? Slide RF to 18?
  7. thread starter macrumors 6502a

    Sep 30, 2010
    Yes, downloaded it about 12 hours ago.

    I don't know if it's safe, all i can say for now is that i haven't seen any issues yet. RF is up to you depending on what quality you like.
  8. macrumors regular

    Feb 1, 2010
    Great. This is the build that allows DTS to AC3 as well? Man, these guys have an awesome product.

    These forums are great if you can sift through all the complaining! :D
    I've learned some really cool things with MakeMKV, Handbrake and auto-tagging/adding to iTunes with Automator & Hazel. Making safe backups for my Blu-rays is becoming really simple.
  9. thread starter macrumors 6502a

    Sep 30, 2010
    Yes DTS to AC3, id been hanging out for it for ages just was added today.

    Would be good is Apple put this much effort into their work then we wouldn't be seeing this stuttering issue.
  10. macrumors 6502a

    Oct 5, 2010
    OK, I'm stuck with Windows, and the latest Windows GUI apparently does not have DTS working yet, so perhaps it also lacks whatever magic might have fixed your problem. I downloaded/installed it, used your settings, and just converted the first 120 seconds of my movie, since that's where I've got the scene I want to closely inspect anyway.

    So far, no good. Two things:

    1) The movie is playing in the wrong aspect ratio (it's displaying as 4:3 with black bars on the left/right). I believe that this is because I set Anamorphic to "None" per your recommendations. Should I have also then checked the "Keep aspect ratio" checkbox? Or perhaps I should be using a different Anamorphic setting?

    2) I'm still seeing the stutter.

    I really don't think my problem is related to me not being on quite the latest build, though, as it seems like the only significant change that was made to that build was support for DTS -> AC3. I'm now thinking that the problems you were having before are different than the *very subtle* stutter issues I'm still seeing.
  11. macrumors newbie

    Jul 16, 2002
    Anchorage, Alaska
    I posted this in the thread about the Apple TV handling 1080P, but thought I would repost here, in case it helps to figure out what's going on.

    Some observations of mine, so far.

    First, my setup. I've got the Apple TV connected to an Airport Extreme via Wi-Fi, a Mac Mini and a Mac Pro 8 core connected to a Gigabit switch, and a Syswan SW24 Dual WAN router.

    I tested the Lion of Judah, and a Harry Potter trailer to see how they played. They both appear to play fine, no dropped frames/stuttering (I've been working in the television industry for over 20 years, so I know what to look for).

    Looking at the Mini's processor load, it appears that the host computer is doing the conversion from 1080P to 720P. So, if you have a high load on your host while the video is being converted/streamed it may lead to dropped frames/stuttering, and once loaded into the Apple TVs buffer, it would repeat that same stuttering each time you play it.

    Now, I still need to do a lot more testing, so I wouldn't consider my findings definitive by any means. But, if iTunes is having to convert a file to stream to the Apple TV, even if it's already a 720P file, and the host cpu is under heavy load, that may explain why some people are seeing the problem and others aren't.

    Just my 2¢

    Hope this helps.
  12. macrumors 6502

    Apr 17, 2010
    I've also noticed an occasional very subtle stutter with HD iTunes purchases, not enough to disrupt the show or movie, but enough to irritate me a bit. Even though the video appears to be fully buffered, I tried switching from wireless to a wired (powerline) connection. Still happens, but not as often.....I think.
  13. thread starter macrumors 6502a

    Sep 30, 2010
    I would have to say 100% sure the stuttering has nothing to with handbrake when others are reporting that the iTunes rentals behave the same way and stutter.

    I think all we can do is wait and hope that Apple fixes this issue.
  14. macrumors 6502a

    Oct 5, 2010
    Now you're confusing me. I thought you indicated previously that the latest Handbrake build fixed the problem for you? I've encoded yet another version, but my daughter's watching something on the aTV over Netflix right now, so I have to wait for her to go to bed. I'm not optimistic, though.

    At some point I'm probably going to have to make a decision as to whether to try not to look for the problem and see if I can be happy, or switch back to using my Acer Revo w/XBMC and hope that Apple eventually fixes it via a firmware update.
  15. thread starter macrumors 6502a

    Sep 30, 2010
    How can handbrake be causing the issue ? when even the iTunes store Rentals show the stutter ? I doubt very much Apple use handbrake to encode their movies.

    To me this seems like some TV's can't convert whatever the Apple Tv is putting out 60fps 50/60hz
  16. macrumors 6502a

    Oct 5, 2010
    I'm not saying that Handbrake is causing the issue (I don't think it is), I'm just confused, because a previous post of yours suggested that the latest build of Handbrake produced videos that didn't have the issue, which would indicate that *you* were suggesting that Handbrake was the issue. What am I missing?
  17. macrumors regular

    Sep 11, 2008
    Yes, I am getting this very subtle stutter as well when playing back HD content.

    I used the standard ATV preset as well as the high profile, and the stutter persists on both encodes.

    My apple TV version 1 handles the ATV standard encode just fine.
    This means there is something 'different' about the new apple TV.

    The stutter occurs at regular intervals, is very slight, and is not related to graphically intensive scenes.

    Others have reported the same stutter with HD Itunes rentals.

    Some have suggested that a process that runs in the background at regular intervals is the culprit.
  18. thread starter macrumors 6502a

    Sep 30, 2010
    I have only seen the issue with encodes i done for the previous Apple TV.

    Strange that you are seeing them with the high profile preset.
  19. thread starter macrumors 6502a

    Sep 30, 2010
    Yea all i meant was the the latest nightly build with the High Profile preset was playing fine with no stutter. I never thought or suggested handbrake was a fault.

    I have movies encoded with different apps and they stutter, even a movie i bought from the iTune store a couple years back stutters.

    When anamorphic is off you should check Keep aspect ratio
  20. macrumors 6502a

    Oct 5, 2010
    Here's what I just posted in the Handbrake forums...

    My latest test still gets the stutter problem. Really aggravating. I just want to reiterate that you probably have to look closely to see this, so I suspect that many people who are reporting that they are getting flawless playback are simply not seeing it but are, I'm sorry, mistaken. I've played *so many* variations of this clip, all encoded with Handbrake at several variations in settings, and they all have the problem. I've also played every single one of these clips on my Acer Revo nettop running Windows 7 and XBMC, and going to the exact same TV (a Sharp 52" 120Hz 1080p LCD), and they all play perfectly smoothly.

    So the good news is that Handbrake is pretty great. I can take my 1080p uncompressed Blu-ray rips at 18GB+ and get them down to 3GB 720p files which still look great. The only catch is that I have to play them on my nettop, as my new Apple TV can't play them perfectly.
  21. thread starter macrumors 6502a

    Sep 30, 2010
    Strange that you are getting the issue when i am not. Anything i have encoded with High Profile works flawlessly. It's just encodes i have done for the previous Apple Tv that once the movie is fully buffered it starts to stutter.

    Have you tired this on another source ?

    What happens is you download the 1080p Lion of Juda trailer from the Apple website and encode it with High profile set to 1280 by 720.

    Also use another application to encode the video.
  22. macrumors newbie

    Jul 2, 2010
    Hey guys, I had lots of problems with my box stuttering, with my handbrake encodes. I took my box back and got it replaced, and it still stuttered during playback of movies and tv shows - it was even doing it to shows which i paid for in iTunes. I then decided that since the second box was still stuttering, that it wasn't my computer that was at fault, and it wasn't the Apple TV either. The fault is caused by the refresh rate of the Apple TV with certain TV scalers. I have a Sony 46" hx703 and I was getting the problem. To solve the problem, all I needed to do was change the scaling mode from film mode 1 to film mode 2. I think all the stuttering problems are being caused by different pulldown ratios with different tv scalers over the HDMIs. Hope this helps if any one needs help message me and i will see what i can do.
  23. macrumors 6502a

    Oct 5, 2010
    Well, I want to watch my video clip a dozen more times before I say so for sure, but I think you might have nailed it. If so, I feel like a dope, too, because monkeying around with my Acer Revo w/XBMC settings to replicate what the Apple TV is doing (sending 720 @ 60Hz) is something I had meant to experiment with. I kind of discounted the possibility before because I've seen judder on my XBMC box (same scene) and it was more constant. In that panning space scene, it would happen every second (maybe more), whereas with the Apple TV, I was seeing a glitch more like every 10 seconds (I didn't time it, I'm just pulling that number out of the air).

    But based on your comments, I cracked open my Sharp Aquos 120Hz LCD manual and looked to see what options were available. There are three 3:2 film-related settings available. The default was labeled "Low" (whatever that's supposed to mean). There's also a "High" setting, so I tried that. If anything, the glitch seemed a bit worse or more frequent, but I can't say for certain (more testing required). And then there's an "Off" setting. With that option set, I *think* that I'm not seeing any glitches, *BUT* the overall motion seems less smooth. Rather than appearing as an occasional glitch, the overall motion feels like it's running at a reduced framerate or something. I'll have to test this out with other clips to see which of these two evils is more bearable, or if they both drive me crazy.

    My TV also has a "Fine Motion" (I think that's what they call it) mode which is supposed to be better for fast action. Not sure what that's doing behind the scenes, but I may toggle that on/off see if I can make out any improvements.

    One of my next tests will be to hook up my Apple TV to my Panasonic AE-700U LCD projector which is native 720p, to see if things are any better or worse there.

    Maybe I'm just spoiled having seen how things look on my Acer Revo w/XBMC. That sends out the native sync rate (24p in this case), though I believe it is upscaling it to 1080p.
  24. macrumors 68000


    Feb 23, 2006
    Ft. Lauderdale
    Where do you find this setting? Is it on the tv end??
  25. thread starter macrumors 6502a

    Sep 30, 2010
    I have always suspected the Tv refresh rates had something to do with it.

    But why only on some videos and only once the video is fully buffered on the Apple TV. ?

    Just tested it now playing a Bluray rip of Coming to America, it plays perfectly but as soon as it has fully buffered on to the Apple TV it starts to stutter.

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