AppleTV 2 HD Playback Issue

Discussion in 'Apple TV and Home Theater' started by jmagelitz, Jan 11, 2012.

  1. jmagelitz macrumors newbie

    Joined:
    Jan 11, 2009
    #1
    I'm very new to AppleTV 2 and just jailbroke v4.4.4 and bought it because I had heard it was capable of playing 1080p video. While trying to play even a 720p file from icefilms (XBMC 11.0 Eden beta) it skips repeatedly. Is there any way to watch HD preferrably 1080p without that issue? Is it maybe an issue with my internet/router? (Its plugged in by Ethernet, not wifi) or do I need to update the video card inside the atv2 (heard of a card named crystal card, but don't know much about it). Thanks for all helpful replies.
     
  2. Praksis macrumors member

    Joined:
    Aug 31, 2011
    Location:
    Portugal
    #2
    I have a ATV2 as well, only difference is that i didn't jailbreak it but i've read posts from many ppl that did and they also did not have any problems viewing HD content.

    Mine works like a charm both streaming live from the web and from my iTunes server.

    My bet is that the issues you're having are related to poor/slow internet connection.

    P.S.: i'm using a version 1.4 HDMI cable instead of a cheap one to connect the ATV to my TV, they are optimized for high speed data transfer. That might be a issue as well since you're streaming HD content that contains large data blocks.
     
  3. whooleytoo macrumors 603

    whooleytoo

    Joined:
    Aug 2, 2002
    Location:
    Cork, Ireland.
    #3
    I've been able to play 720p video without any skipping, and can scrub forward and it'll still play fine. I've even tried playing 1080p video (though my ATV isn't jailbroken, so it just downscales to 720p) and that plays without skipping too.

    Obviously though, it depends on the video's bitrate. A compressed 720p video might have a data rate of about 5-6Mbps, whereas a non-compressed 1080p video could be as much as 30Mbps+. 1080p videos should play fine if the data rate isn't too high.
     
  4. hafr macrumors 68030

    Joined:
    Sep 21, 2011
    #4
    If a 720p film in Icefilms has choppy playback it's because it's coded in XviD. The ATV2 does not handle XviD very well. Some of their HD content is in XviD, some is in h264.

    Changing the graphics card is possible in the ATV1, not in the ATV2.

    ----------

    http://reviews.cnet.com/hdmi-guide/
    http://news.cnet.com/8301-17938_105-20056502-1/why-all-hdmi-cables-are-the-same/

    and so on and so on...
     
  5. Rddl macrumors newbie

    Joined:
    Jan 1, 2012
    #5
    The AppleTV 2 is indeed capable of playing back 1080p video, but the specs need to be reasonable. H264 (not XviD) in an MP4 container, High@L3.1 profile, and a bit rate reasonably close to 5mbps.
     
  6. M Quick macrumors 6502

    M Quick

    Joined:
    Nov 9, 2011
    Location:
    Stockholm, Sweden
    #6
    Just because you read it on the internet doesnt make it true, there is a reason for v1.4 hdmi, and I personally have noticed a difference, for example, a v1.3 wasn't able to output 60hz (only 30hz) until we got a v1.4 cable just for giggles and it turned out to show 60hz just fine.

    So no difference you say?
    you know why some cables are better than others, right? I'm guessing you have the cheapest cables at home?! No?
     
  7. hafr macrumors 68030

    Joined:
    Sep 21, 2011
    #7
    Dude, stop crying. If you think choppy playback on HD content on Icefilms is due to a v1.3 cable being used, of course you're allowed to - but you're wrong. The easiest way to explain this is to show you the comparison: http://en.wikipedia.org/wiki/HDMI#Version_comparison

    But an actual reason to question that v1.3 would be the issue is that v1.3 does BluRay (50 mbps), so assuming choppy sub 10 mbps playback would be because limitations on large data transfer is quite strange. Another reason is that if it would be the cable, the problems would be a lot more obvious than choppy playback for HD content on Icefilms. Yet another reason is that it's a well known fact that certain HD films on Icefilms are coded in XviD, and the ATV2 doesn't use hardware acceleration for XviD.

    Also, don't confuse cheaper cables with older standards.

    Or maybe the reason why I have no problem watching movies at rates over 13 mbps during action scenes in 1080p x264 rips to my ATV2 but have choppy playback during 720p XviD rips at sub 5 mbps is due to my cheap cable's data transfer limitations...
     
  8. M Quick macrumors 6502

    M Quick

    Joined:
    Nov 9, 2011
    Location:
    Stockholm, Sweden
    #8

    I'm crying? Say what?

    I didn't argue against what you are telling me now, so I'd say I'm not the one crying here.. Obviously..

    I'm saying that a v1.3 cable is NOT the same as a v1.4 cable, which you are.
    I even told you why.. Because you're coming out as if 1.4 is the exact same cables as 1.3 cables..
     
  9. hafr macrumors 68030

    Joined:
    Sep 21, 2011
    #9
    No, what I'm saying is that his problem is not caused by using a v1.3 instead of a v1.4 cable, which you claimed could be the case.

    Am I saying v1.3 is the same as v1.4? I even posted a link to a comparison between the two where you can see the differences. The earlier links to expensive vs. cheap cables were to underline the fact that his problems would not only be choppy HD playback on Icefilms if it was in fact the cable. Also, I thought I was pretty clear on the fact that you shouldn't confuse cheaper cables with older standards.
     
  10. peterjcat macrumors 6502

    Joined:
    Jun 14, 2010
    #10
    There is no such thing as a 1.4 cable or a 1.3 cable. There are Category 1 (Standard) and Category 2 (High-Speed) cables. Both of these categories are defined by the HDMI 1.3 specification -- Standard is rated up to 720p/1080i, and High-Speed is rated from 1080p and up. These ratings have no correspondence whatsoever with HDMI version, which only applies to the sockets and never to the cables.

    Of course there are also good cables and crappy cables, and good cables will carry higher bitrates whether they're rated as Standard or High-Speed. A crappy cable will result in sparklies or total picture loss. It will never result in choppy video playback.

    And back to the OP: the ATV2 can't output at 1080p no matter how jailbroken you are; anything it plays will be downscaled to 720p. So don't worry about those 1080p streams, and when you're playing 720p remember that the ATV2 only has hardware acceleration for H.264 and for SD MPEG-4 Part 2 (including Xvid/DivX).
     

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