HD Resolutions

Discussion in 'Apple TV and Home Theater' started by J@ffa, Apr 10, 2007.

  1. J@ffa macrumors 6502a

    J@ffa

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    #1
    Can anyone tell me what resolution I should pick for an Apple TV? The screen it's connected to supports up to true 1080p, should I go for 720p or 1080i? Also, I know it's not supported by the Apple TV, but is 'p' better than 'i'?
     
  2. Cabbit macrumors 68020

    Cabbit

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    #2
    i = interlaced, lower quality
    p = progressive, higher quality and better with fast motion

    You are best to set it to 720p this is the HD standard not 1080i,1080p.

    Also note 480p is HD its just not as glamorous as its bigger sisters.
     
  3. Super Macho Man macrumors 6502a

    Super Macho Man

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    #3
    1080i = 1920x1080 interlaced (30 fps)
    720p = 1280x720 progressive (60 fps)

    Neither is "better" than the other. 1080i simply contains more spatial resolution while 720p contains more time resolution. If your TV displays 1080p, it's your choice whether you want to interpolate the space info (with 720p) or the time info (with 1080i).
     
  4. ftaok macrumors 601

    ftaok

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    #4

    Not to pick a fight, but 720p isn't "the" HD standard. It's just one of the HD standards. 1080i and 1080p are also HD standards.

    As for the original poster's question, I would suggest trying both 720p and 1080i and judging which one's better. There are tons of variables that come into play. For instance, you may find that the aTV does a better job upscaling 720p videos to 1080i than your TV does. In that case, it's probably better to set the aTV to 1080i so that all your TV is doing is the de-interlacing.

    However, if the TV does a better job with upscaling, then it might be better to set the aTV to 720p and let the TV upscale to 1080p. This would get rid of the interlace/deinterlace step.

    It's probably not too hard to mess with the settings on the aTV to see which one works better in your set-up. You probably want to play around with several different file types/resolutions, as well as photos.

    BTW, this is assuming that your TV displays 1920x1080p. There are several TVs out there that can accept a 1080p signal, yet only displays 768p (either 1366x768 or 1024x768). The 42" and 50" Pioneer plasmas come to mind.

    ft
     
  5. benpatient macrumors 68000

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    #5
    also....

    480p is NOT NOT NOT "HD."

    it's just not. It looks a good lot better than 480i (especially with natively widescreen material (720x480 for example), but it isn't "HD" by anyone's standards.

    it'd usually referred to as ED or "Enhanced Definition" by manufacturers, although this isn't a "standard" in the way that 720p/1080i is a "standard." All of the old 42inch plasmas were 848x480 and they called them EDTVs.

    look stuff up before you post it as fact, if you don't actually know.
     
  6. Erendiox macrumors 6502a

    Erendiox

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    #6
    To make simple sense of where 720p and 1080i are most effective, think of it this way. If you're watching an action movie, go with 720p because of all the fast movement. If you're watching a soap opera, or something else with very few fast movements, go with 1080i. It's almost impossible to see the difference between interlaced frames and progressive frames without a great deal of motion. A shot that is not moving will look spectacular in 1080i, and not quite as spectacular in 720p. Once that shot starts moving around alot, if you look closely, you can see small tearing artifacts in 1080i, artifacts that are nowhere to be found in 720p. That's what you want to think about when choosing between them. 1080i has better quality, but doesn't handle motion as well. Personally, i'm 720p guy, cause I like the crisp movement. I don't watch soap operas :p .

    Oh, and btw, benpatient is right. 480p is NOT HD. It's just a progressive version of standard definition.

    Cheers :)
     
  7. GregA macrumors 65816

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    #7
    Fortunately, the AppleTV's limitations make your choice less critical.

    AppleTV can not display better than 720p24. What this means is 24 frames per second for 720p resolution. So if you tell the AppleTV to output 1080i it will upscale the picture & interlace it, but it's still only 24 frames so it will send multiple copies of the same frame.

    Your TV, assuming it has a GOOD de-interlacer, will pick those 24 frames out and re-interlace them perfectly using 'weave' (it can do this with any 24fps files the AppleTV has interlaced - note that video files can not be de-interlaced perfectly because they were recorded interlaced but that the AppleTV doesn't support their frame rate anyway).

    So really, for AppleTV's 720p24 source on the latest TVs, the interlaced or progressive signal will make no difference. (But if you have a HD screen which doesn't de-interlace well it may de-interlace by simply halving the resolution to 540p.)

    As for the resolution - as someone else has said - if your TV actually can show 1080p, then the quality will depend on whether the TV or the AppleTV is more capable of upscaling the signal. I doubt it will make much difference.

    All up, I'd recommend 720p as the output resolution of the AppleTV.

    edit: Not because your TV will gain much over 1080i, but because it certainly won't lose anything. 720p is more foolproof for other people who don't understand the capability of their TVs.
     
  8. The General macrumors 601

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    #8
    If you can't tell the difference, the who cares? :confused:
     
  9. ctakim macrumors 6502

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    #9
    Actually, if you are viewing a film source, I would suggest that 1080i is theoretically a good choice because films are shot at 24fps. If you have a good internal deinterlacer in the TV, then the even and odd scan lines in a 1080i 60 fps will completely recreate the film frame from the original source in a 2:3:2:3 pattern with (thoretically) all the information contained in the original 1080p source deconstructed to 1080i, transmitted to the HDTV, and then reassembled as 1080p on the display. Aside from the 2:3 induced judder, there is no motion blur that is not already present on the film source.

    Theoretical handwaving aside, try both and see which you like. If you wouldn't mind, please compare the outputs with a variety of different sources and report back here which you think is better (and why). TIA:)
     
  10. GregA macrumors 65816

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    #10
    Exactly true on the de-interlacing comment.

    Remember 3 things though
    1) Most plasmas are 768 lines (720p). They downscale 1080 material
    2) The Apple TV can't transmit a 1080p source. It does 720p - which it can upscale to 1080i if you want (most plasmas will then downscale it)
    3) If your TV does NOT have a good internal deinterlacer, it'll take that 1080i and create 540p from it.
    I can't find any combination of factors that would make 1080i better, hence my recommendation for 720p on the AppleTV. 1080i, on SOME TVs, would look worse.

    I don't have an AppleTV myself, I'm playing with my parents system when I visit them.

    The 2:3 induced judder (24 frames per second, split into 60 hertz refresh rate) is avoided on their Pioneer plasma by setting it into a cinema mode which uses a 72 hertz refresh.

    For this reason, even though we are in a pal country (50Hz), I set the AppleTV and the Plasma to NTSC.

    On my parents TV the differences should be negligible. Unfortunately, the HDMI on the Amp only allows 720p (not 1080i) so I can't compare without some major rewiring.
     
  11. illegalprelude macrumors 68000

    illegalprelude

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    #11
    1080i not = 1920 x 1080

    thats 1080p

    As far as it goes, if you have a nice HD TV, you can notice the difference between 720p and 1080i and 1080p.

    That can unfortunatly have a downside as being a current 1080p owner, AppleTV vids, like I just downloaded Season 3 of Battlestar Galactica and it looks frakin whorible. Looks worse then DVD. Guess im spoiled by Blu-ray but still, im cool with DVD and this for sure. looks worse
     
  12. GregA macrumors 65816

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    #12
    yeah DVD is 720x480
    iTunes is 640x360 (assuming it's widescreen. 640x480 is only for 4:3)

    Come on AppleHD :)
     
  13. ftaok macrumors 601

    ftaok

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    #13
    There are two items that no one has yet mentioned, regarding 720p or 1080i.

    1. The menus will (probably) look much sharper with the aTV set at 1080i. Not that this is any big deal.

    2. Photos and slideshows will look much sharper with the aTV set at 1080i. This is a bigger deal.

    Of course, this is assuming that the display device truly displays a 1080p picture. Even though a TV says it accepts 1080p, doesn't mean it displays 1080p. The general rule of thumb is to match the resolution of the output device as close to the display device's native resolution.

    ft
     
  14. GregA macrumors 65816

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    #14
    What makes you think the AppleTV will display at greater than 720p24?

    Their specs say they can't handle greater.
     
  15. Super Macho Man macrumors 6502a

    Super Macho Man

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    #15
    Movies are generally 24fps. All film movies will look better in deinterlaced 1080i than 720p. It's the right idea, though.
     
  16. ftaok macrumors 601

    ftaok

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    #16
    Well, the aTV is very capable of displaying 1080i. It's in the specs. I think you're confusing what the aTV can play (in terms of video resolution) vs. what it can display (as in output resolution).

    The aTV is currently limited to playing 720/24p video files. This is most likely due to the the aTV lacking sufficient horsepower to play 1080i/p files. Photos are a much different story. You don't need very much horsepower to display a photo (scaled to 1920x1080), even if you throw in the Ken Burns effect and a little music. Heck, my iBook G3 can handle a slideshow with all of the bells/whistles with no problem, and that's with the overhead of OS X (granted, the iBook is only pumping 1024x768). I'm sure the aTV with a 1Ghz Pentium M and the decent video card will have no problems playing a 1080i photo slide show.

    ft
     
  17. wake6830 macrumors regular

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    Jan 24, 2007
    #17
    Actually, 1080i and 1080p both have the same resolution, but 1080i material is interlaced and 1080p material is not. The difference between the two is not the number of pixels or vertical lines, but how often those lines are refreshed.
     
  18. The General macrumors 601

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    Jul 7, 2006
    #18
    Did you download the 720p rips from Universal HD, or did you download the 480i Sci Fi ones ... because I downloaded the 720p ones and they look great. Of course, as great as BSG can look. They seem to add a grainy effect to the entire show. It really bugs me. :rolleyes:

    I transcoded them to 1280x720 H.264 mp4s, slapped them on my :apple:TV and watched them on my 1080p LCD. There's some problem with my TV and the 1080i signal the :apple:TV puts out ... there are weird lines on the top and bottom, so I have mine set to 720p.

    Hopefully I can get the ATVFiles plugin installed, as well as the Xvid, Divx, and Matroska Quicktime components to work. Then I won't have to transcode them. :)
     
  19. illegalprelude macrumors 68000

    illegalprelude

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    #19
    wait. where was the 720p Vids at? :eek: :eek: I just went under TV shows and searched BSG and downloaded season 3 :eek:
     

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