OTA HD vs Mpeg4 HD

Discussion in 'DirecTV TiVo Powered PVRs & Receivers' started by buzzmc1, Dec 22, 2005.

  1. Dec 22, 2005 #1 of 118
    buzzmc1

    buzzmc1 New Member

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    I'll try and politely ask that only people respond with direct experience, watched side by side, etc, which will likely limit my responses a lot.

    I hear a lot of people bashing D*'s MPEG4 HD offerings, that OTA looks much better, the MPEG4 feeds are down-rez'd, etc.

    While I image the new MPEG4 feeds use less bandwidth, and some might argue more compressed, I would hope that the new mpeg4 technology does a better job w/bandwidth and that what we would think of as "more compression" doesn't really show up all that much, except for the most picky eyes.

    I think there's a lot of people that just like to bash for the sake of bashing... If it isn't PERFECT, then it's garbage.

    Anyway, on to the meat of the matter ... How does it look? Is there a HUGE difference between OTA vs D*'s MPEG4 HD?

    TIA!

    -b
     
  2. Dec 22, 2005 #2 of 118
    edrock200

    edrock200 New Member

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    Northern...
    I'm going against your first rule here, as I have not seen a side by side comparison, but I will say if the new HD PVR allows me to chose recording from ATSC or MPEG4 sources I would chose MPEG4 everytime unless the quality was significantly different. The reason being that MPEG4 *should* take up significantly less space on the hard drive than MPEG2, which will allow me to store a lot more HD per GB.
     
  3. Dec 22, 2005 #3 of 118
    jcricket

    jcricket New Member

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    Of course if DirecTV plans on only using hard drives 2/3 the size of the HR10-250 hard drives in their HD-DVR, then you still end up with the same amount of recording capacity.

    I really hope the HR20 ends up with the capability to add drives, or better yet, comes with a 300+GB drive, even with MPG4 using less space. But I'm not holding my breath.
     
  4. Dec 22, 2005 #4 of 118
    bpratt

    bpratt New Member

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    Several months ago D* had several programs they broadcast in MPEG2 HD that looked as good as OTA HD programs. Since then, they must have reduced the amount of bandwidth they allocate to HD programs because they no longer look as good as OTA.

    I believe D* could broadcast either MPEG2 or MPEG4 and match the quality of OTA HD broadcasts if they are willing to allocate enough bandwidth. Whether they will or not is another question.
     
  5. Dec 22, 2005 #5 of 118
    coachO

    coachO New Member

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    It is hard to compare OTA and D* as I suspect neither are broadcasting at the proper HD Spec. Having said that, my OTA HD do not look any better or worse than National D* channels.
     
  6. Dec 22, 2005 #6 of 118
    edrock200

    edrock200 New Member

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    Northern...
    But unless I'm mistaken the HD PVR's will have both ATSC tuners and mpeg4 tuners, so you will always have a choice of recording mpeg2 or mpeg4 (if locals are available in your area), so no matter how much hard drive space they come with, you'll get more storage chosing mpeg4.
     
  7. Dec 23, 2005 #7 of 118
    newsposter

    newsposter Poster of News

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    do you mean that your ABC local OTA in HD is not better than, for example, SciFi on directv? If so, somethings really wrong there. Heck even my OTA SD is so much better than the DTV compressed stuff in philly, that I record survivor OTA and enjoy with the bars and additional disk space used up.

    So in philly I can say with certainty that OTA beats DTV on all but the HD sho and hbo that I get
     
  8. Dec 23, 2005 #8 of 118
    TyroneShoes

    TyroneShoes HD evangelist

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    Your conclusion is right, but your facts supporting it are a bit fuzzy. More accurately, the box has ATSC and DVB tuners, and includes both M2 and M4 decoding. A tuner selects and demodulates a modulated carrier to baseband information, and a MPEG decoder converts the information to HD SDI digital video. DAC conversion then either happens in the Tivo (component) or in your display (HDMI). But a tuner is not a decoder, and a decoder is not a tuner. The HR10 does all of this except for the M4 decoding.
     
  9. Dec 23, 2005 #9 of 118
    edrock200

    edrock200 New Member

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    Northern...
    Thanks for the clarification. I know that the tuners don't have anything to do with the mpeg decoding but I didn't know the term for the DirecTV tuners (from your post I'm guessing DVB) so I just referred to them as "MPEG4" to differentiate them from the ATSC tuners.
     
  10. Dec 23, 2005 #10 of 118
    TyroneShoes

    TyroneShoes HD evangelist

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    It's probably easier to think of the PVR as having 4 tuners that are always active, two of them sat and two of them OTA, and two decoders that can each handle both M4 and M2 (assuming the new PVR will have the same basic architecture as the HR10). On the HR10 you can actually "receive" 4 signals at a time, but you can only route the demodulated output of two of them into two paths that write to the HDD, and likewise there are but two paths that can be accessed from the HDD to the buffers, and only one of those can be visible on screen at any time. The key is the internal routing of the various modules that do the different tasks.

    Hmmm. Maybe that's not easier.
     
  11. Dec 23, 2005 #11 of 118
    edrock200

    edrock200 New Member

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    Northern...
    lol, yeah I get all that. I understand it, I swear! hehe, thanks for the write up though, its a better way to think of it...4 tuners, 2 sets of 2 decoders and routing.

    *edit* sorry for the mini thread-jack.
     
  12. Dec 23, 2005 #12 of 118
    darthrsg

    darthrsg New Member

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    post 911...
    what about the OP? i would like to know as well.
     
  13. Dec 23, 2005 #13 of 118
    newsposter

    newsposter Poster of News

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  14. Dec 23, 2005 #14 of 118
    AbMagFab

    AbMagFab What happened, TiVo?

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    Locals are natively MPEG-2. No matter what DirecTV does, any transcoding of the signal will at best be slightly worse. You might not care if you have, say, a 720p TV, but you'll notice on a 1080p TV.

    If you can get strong OTA, DirecTV locals are useless (and OTA suffers almost zero rain fade).
     
  15. Dec 23, 2005 #15 of 118
    edrock200

    edrock200 New Member

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    Damn, nothing broadcasts in 1080p yet but we're already dissing the 720p and 1080i sets. lol
     
  16. Dec 24, 2005 #16 of 118
    AbMagFab

    AbMagFab What happened, TiVo?

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    First, 1080i is fully resolved on a 1080p set, but not on a 720p set (and arguably not on a 1080i set, since all 1080i sets are analog, and most of those actually do 540p). Most HD is 1080i today, and thus fully realized on a 1080p set.

    It has nothing to do with a 1080p source.

    Second, any resolution loss will be more visible on a 1080p set. For example, today DirecTV is downrezzing all HD content to a weird mix of 1080i and 720p. However you won't see too much of a difference on a 720p set, but if you have a 1080p set you can see a difference (again, since all the pixels are visible only on a 1080p set).

    MPEG-4 transcoding will involve it's own translation losses, even if they keep the full resolution in place (which I doubt they will, IMO). This again will be visible on a 1080p set, but likely less so on a 720p set.

    edrock200 - feel free to lag technology, but don't mock what you don't understand.
     
  17. Dec 24, 2005 #17 of 118
    edrock200

    edrock200 New Member

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    Northern...
    Huh?! I wasn't mocking you at all, just making a joke, relax bro.

    That said, abmagfab, I've always respected your opinion and contribution to the boards, but I think you misread my joke as mocking. I understand the difference between 1080p and 1080i and even invested in a 1080p set this holiday (though I'm not convinced they look any better and certain distances.) Regardless, sorry if my post came off as mocking, it was intended to be so.

    To the OP, sorry, last threadjack I swear! :)
     
  18. Dec 24, 2005 #18 of 118
    dswallow

    dswallow Save the ModeratŠ¾r TCF Club

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    DVB-S is a standard which is partially followed by Dish Network. DirecTV uses their own "standard" referred to as DSS.
     
  19. Dec 24, 2005 #19 of 118
    bdlucas

    bdlucas Right side up again.

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    Sounds like a good reason to save money and not buy a 1080p set. ;)
     
  20. Dec 24, 2005 #20 of 118
    Ein

    Ein New Member

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    But, have to plan for the future. (Blu-ray, PS3, etc) :)
     

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