Technical: Streaming HD to MBA connected to TV

Discussion in 'MacBook Air' started by Mikegs, Dec 27, 2010.

  1. Mikegs macrumors regular

    Aug 6, 2010
    Hi guys

    I am currently streaming an HD movie to my MBA 11.6 "ultimate". It plays fine. However, when connecting to my HD-TV there is some stuttering.

    But why?

    Isn't it the same amount of data being processed with or without the TV connected (but downscaled to fit the MBA's resolution when not connected to the TV)? I just figured it would require no more processing power playing the movie in 1080p and downscaling it to the MBA's resolution than playing and showing in 1080p on the TV? Or does the M´BA somehow process only part of the data, when full 1080p is not utilized (ie not connected to the TV)?

    Thank you for any elaboration on this issue!

    PS: The movie plays in MS silverlight. Any way to make in not stutter on the TV?
  2. kory108 macrumors member


    Nov 17, 2008
    Milwaukee, WI
    I'm assuming you have your mac connected to the TV via a mini display port to HDMI converter? What does the processor look like in Activity Monitor? You're probably just pegging out the processor, which can happen on the slower 11.6 inch models rather easily.
  3. entatlrg macrumors 68040


    Mar 2, 2009
    Waterloo & Georgian Bay, Canada
    No stuttering on my 11".

    Need more details, what are you streaming from, how connected, what software are you using?
  4. Over Achiever macrumors 68000

    Over Achiever

    Jul 22, 2002
    Toledo, OH, formerly Twin Cities, MN
    Need more details. I've connected my 11 MBA to my TV quite a few times now, streaming full HD on Netflix via Displayport -> HDMI. No studdering.
  5. Mikegs thread starter macrumors regular

    Aug 6, 2010
    I am streaming from a video on demand store using microsoft silverlight The point of this discussion is: does it required more system power to view on external tv as opposed to view on The MBA and if so, why? I would Think it is The same amount of data being processed. I also have locally stored hd movies without studder on The external screen, but that doesn't necessesarily mean it does not require more power to get it on The ext screen, just can't figure out if This is The case... Anybody know if it does?
  6. Mikegs thread starter macrumors regular

    Aug 6, 2010
    And the connection is a miniDP to HDMI cable, no adapter
  7. Dammit Cubs, Dec 28, 2010
    Last edited: Dec 28, 2010

    Dammit Cubs macrumors 68000

    Dammit Cubs

    Jul 31, 2007
    I have had this issue. The way to truly find out what's going on is to put the HD movie on your MBA thats connected to your tv and see if its still stuttering. If it is, then its your processor. If it isn't, then its your network connection.

    I understand that it's streaming the same file because but its actually not. Your TV is doing 1080p while your MBA is doing 720p. Now that shouldn't make a difference, but your macbook, software is deciding how this is being setup: it realizes that it doesn't need to send the full bitrate in order to properly stream on 720p but because it has to populate more pixels on 1080p, it has to send more. Why is that important? Well depend on your network setup, your network work might have some spotting connecting and causing stuttering.

    I know this because I have a Mac mini connected to my TV and I wanted to stream Avatar to my 24 inch monitor (1900 x 1200). It would start to stutter when im doing duel monitor. it was wierd and the stuttering didn't make sense, because when i had the video on my MBA, it wouldn't stutter so I know my wireless router wasn't good in the other room, (half the signal). So I changed routers and it works like a dream I can stream 1080p without any problems.

    That's my two cents just from observation.
  8. Mikegs thread starter macrumors regular

    Aug 6, 2010
    Thanks Dammit Cubs

    However, I am not using wireless transfer from the MBA to the TV, these are connected by cable (Mini-DP to HDMI).

    So the wireless part is between the internet/wireless router and the MBA, and since this is causing no studder on the MBA screen, I am excluding the network as being the issue, right? Even though the file being streamed is not fully utilized when playing 720p on the MBA, all the data is still being downloaded to the MBA and would thus cause studder, also in 720p, if the connection is too slow I think.

    That leaves the the possibility of a more processor intesive job when the system detects that 1080p is fully utilized on the TV. Must be it then, if there are no other causes. If I had the choice of streaming through a different player than MS silverlight, that may resolve the issue, since Plex does a fine job with locally stored 1080p movies on the external screen?

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