OTA HD vs Mpeg4 HD

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

  1. Dec 24, 2005 #21 of 118
    dswallow

    dswallow Save the Moderatоr TCF Club

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    Long...

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    Too-distant future.

    By the time content in HD on DVD is prevalent and affordable, a whole new class of displays will be out.
     
  2. Dec 24, 2005 #22 of 118
    dagap

    dagap New Member

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    And therein illustrates the pointlessness of the OP's question.

    Are DirecTV's MPEG4 HD locals better/worse/same as OTA HD locals RIGHT NOW? Who cares, unless you also know their plans going forward.

    Are they going to keep up the bitrate to ensure everyone's locals are beautiful?

    Or are they going to try and cram ever more channels into their limited bandwidth?
     
  3. Dec 24, 2005 #23 of 118
    AbMagFab

    AbMagFab What happened, TiVo?

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    Correction - Sounds like a good reason not to rely on DirecTV for your HD, and instead use OTA, cable, FIOS TV, streaming HD from a PC, etc.

    There is tons of 1080i HD content available today, more than you could possibly watch. As long as you aren't using DirecTV as your HD provider, a 1080p set provides amazing, amazing picture quality (way above a 720p set). Today.
     
  4. Dec 24, 2005 #24 of 118
    AbMagFab

    AbMagFab What happened, TiVo?

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    Very true. And a point many aren't realizing. Personally, I like to be close to the set, and have a big screen - I want a balance of my field of vision being filled, and minimal head movement required to see the whole screen. If Sony came out with a 70" SXRD (that wasn't the Qualia 006) I would have gotten that.

    If you're going to be more than ~8-9 feet from a 60" 1080p set, it's unlikely you'll see much difference from a high quality 720p set of the same size. Your eyes just can't resolve the pixels. Of course if you're buying a 1080p set today, you probably have a 2 year old 720p set, which isn't as high quality as today's higher-end 720p's, so the difference will be greater.

    Now that's mathematically speaking. It's also true that the 1080p sets just look better. Sets like the Sony SXRD's are newer technology, with better blacks and richer, deeper colors and textures, and all that (and more) is visible at further viewing distances. So while you might not be able to resolve the pixels, you'll still see a difference (although not quite as earth-shattering as you will much closer).

    If you love TV, and have an HD DVR, a 1080p set is a good investment today. You'll want a new one in a couple years when they have 2160p sets anyway... ;) :up:
     
  5. Dec 24, 2005 #25 of 118
    buzzmc1

    buzzmc1 New Member

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    Can you say scope creep?

    All I wanted were the few people fortunate enough to see OTA vs D*'s M4 Locals to post what differences they saw.

    Now we're talking about all sorts of things. :(
     
  6. Dec 24, 2005 #26 of 118
    TyroneShoes

    TyroneShoes HD evangelist

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    When's the last time you saw "DSS" in any of DTV's literature? Many years ago, I would think, although it can be found in remnants of old internet sites. DSS is only an acronym for "Direct Satellite Service", which is an all-encompassing term that they were fond of back in the USSB days. DSS does not refer to a transport protocol, as does DVB.

    DirecTV originally claimed to be using a "proprietary" protocol back in 1994 when they were using equipment that encoded at a standard somewhat less than MPEG-2, but somewhat improved over MPEG-1. They even referred to it as MPEG-1.5 for a time. Within a few years they had upgraded to all MPEG-2 gear, and I think it was revealed quite some time ago that what they were using by then for a transport protocol was also a variant of DVB, which has numerous flavors. DISH has always used a common variant of DVB, and has always been only MPEG-2. The ASI protocol that many DT OTA stations use to transport compressed digital video from place to place is also a variant of DVB. There is a DVB-C used by CATV, and other variants used by television digital ENG using COFDM modulation, but all of it comes under the umbrella of the DVB standard.

    DVB is the standard for transporting digital video that is based on encapsulating MPEG-2 video, and was a replacement for the older analog "-MAC" protocols. It might actually be the only one in common use today. Depending upon the application, other data is added to the transport stream to fit the task at hand. Is DTV still using a "proprietary" protocol? I don't think they are any more, but then I've been fooled by DTV before.
     
  7. Dec 24, 2005 #27 of 118
    dswallow

    dswallow Save the Moderatоr TCF Club

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    Actually they stopped calling it DSS because of trademark issues; they now just refer to it as DIRECTV's transport stream.

    If oyu look through Broadcom's chipset offerings you'll repeatedly see reference to them supporting "Standard MPEG-2 output in DIRECTV or DVB format"
     
  8. Dec 24, 2005 #28 of 118
    TyroneShoes

    TyroneShoes HD evangelist

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    If the resolution used by DTV is 1280x1080, then that is actually the same resolution in the H plane as is 1280x720, and even higher than 1280x720 in the V plane, so any downrezzing of 1920x1080 to 1280x1080 by DTV could not possibly be visible on a display with a native resolution of 1280x720. IOW, you just can't see ANY down-rez effects of "HD Lite" on a native 720p display.

    And even if you could, that assumes the rez of the content actually reaches that high. Much of the telecine equipment used for HD transfers today doesn't come anywhere near that kind of resolution, and neither do a lot of the lenses used in acquisition. Resolution is commonly further compromised by production values, and poor cinematographic technique. The brouhaha over HD Lite and 1080p is overblown, much like the hype of audio gear with flat response from 10 Hz to 100,000 Hz designed for rich, middle-aged listeners who can't hear anything above 14K.

    But, 1080p sets (especially the Sony SXRD) certainly do look a lot better than the earlier 720p technology, not because of the improved resolution, but rather in spite of it, and due to the many other improvements that have crept into the technology recently. You can't look at potential resolution in a vacuum, because there are too many other factors involved in what a display ends up performing like. Instead, you just have to go to a showroom and figure out what looks good to your eyes, today. Over-analyzing the reasons why doesn't really buy us much.

    An example of this muddying of statistical info that should but doesn't mean much, is Beta video quality compared to VHS quality. By pretty much everyone's account, Beta was originally superior to VHS in almost every possible technical way that could manifest visually, even after being dumbed down to match the cassette times of VHS, including resolution, color noise, jitter, color gamut, or what have you. But by the time Beta had been all but abandoned, and the models out there still for sale were based on a system that had had no improvements made to it at all for 3 or 4 years due to no one wanting to invest in improving it, VHS, an admittedly inferior system, actually improved by virtue of numerous tweaks to it and the tape formulations used, to the point where in the end it eclipsed Beta from the point of subjective viewing of PQ, which made VHS a better system. It didn't survive because it was better, it got better because it survived, and Beta didn't.
     
  9. Dec 26, 2005 #29 of 118
    Jimmmmbo!

    Jimmmmbo! Eh? I don't get it.

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    Hmm, I just wasted my time reading through this thread hoping to find some insight to the original post. Can't anyone just answer the original post directly, even if it's just "No"?
     
  10. Dec 26, 2005 #30 of 118
    kepper

    kepper Member

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    I've wondered the same about OTA vs. DTV picture quality. I have limited experience (have had the direct tv HR 10-250 for about three weeks) but this is what I've seen.

    Since I live in southern California I get the network west coast HD feed from both D* and from my OTA antenna. My answer to the original poster is- for me, picture quality is sometimes better, sometimes about the same from OTA.

    I notice that CBS consistently seems to be quite a bit crisper with an OTA signal than from D*. NBC seems a little better in OTA, especially in detail resolution (like hair). ABC looks pretty much the same from either source.

    I was wondering why this might be, and I realize there are multiple factors to account for this. One thing that occurred to me is that CBS only broadcasts digitally on channel 2-1. NBC has two channels, 4-1 and 4-2. ABS has three channels, 7-1, 7-2-, and 7-3. I'm thinking that available bandwidth on the OTA digital carrier may account for some of this difference. D* may have to compress the CBS signal more than they do the ABC signal. This assumes that D* is starting with the same OTA feed of these stations as I get, and I don't know if this is true.

    Now, I haven't put a scope on the signal or analyzed the signal electronically. My observations are from watching and having several other people view the programs I've recorded to test this. I have a 32" LCD HDTV so it may be less likely that I see artifacts that someone with a 50" screen would see.

    Kevin
     
  11. Dec 26, 2005 #31 of 118
    dswallow

    dswallow Save the Moderatоr TCF Club

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    Kevin, people are looking for comparisons between the MPEG4 version of DirecTV's signal; with an HR10-250 you're only seeing the MPEG2 version, which is pretty well recognized to be reduced resolution and highly compressed compared to OTA versions.
     
  12. Dec 26, 2005 #32 of 118
    kepper

    kepper Member

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    southern...

    I should have re-read the thread title before posting. DUH! :)

    Kevin
     
  13. Dec 27, 2005 #33 of 118
    TyroneShoes

    TyroneShoes HD evangelist

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    Yes. YOU just wasted your time, not us. The answer is normally in the first 10 posts or so. It's not an easy question, and the answer probably isn't really forthcoming until MPEG-4 implementation becomes common. Actually, asking the question turned out to be a waste of everyone's time, except for the OT conversation it sparked.

    Those of us besides yourself, since the answers are already here as best as they're going to be, have moved on to other related topics. That's the way this works. You're free to stop reading this thread at any time, but no one in the current conversation is all that concerned that the rest of us continuing the conversation makes you unhappy, and we really don't think we need to hear about it, so stop wasting OUR time.
     
  14. Dec 27, 2005 #34 of 118
    f300v10

    f300v10 New Member

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    Well I may be the only person that attempts to answer the original question, but here goes. I am in the Atlanta market, and have had D* HD locals for over 2 weeks. We get the Big 4 of ABC, CBS, FOX and NBC. The 2 720P channels look great, I have never be able to detect any difference between OTA and the D*. CBS looks very good most of the time. I have noticed some artifacts when watching football, mostly with blotchy colors in the grass/turf. NBC on the other hand stinks. Lots of artifacts and noise in the picture. Our NBC does multicast weather+ and I think that may have something to due with the poor quality of the D* version.
     
  15. Dec 27, 2005 #35 of 118
    Budget_HT

    Budget_HT Heavy User (of TiVo)

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    I thought you were going to say there is only ONE decoder, capable of M2 and M4, which is used when decoding a signal read from the hard drive for playback through the outputs of the machine.

    Perhaps I am misunderstanding the role of a decoder in this context?
     
  16. Dec 28, 2005 #36 of 118
    Jimmmmbo!

    Jimmmmbo! Eh? I don't get it.

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    Huh? Whatever.

    The original poster specifically stated "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 simply asked if anyone was willing to try to answer his question. Nice to see f300v10 relate some experience in post #34.
     
  17. Dec 28, 2005 #37 of 118
    Jimmmmbo!

    Jimmmmbo! Eh? I don't get it.

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    Interesting. I wonder if D* is downrezzing the 1080i stuff similar to what it does on the national feeds (such as taking 1920 down to 1280). I don't suppose your equipment is able to tell you what the native signal resolution of the source signal is?
     
  18. Dec 28, 2005 #38 of 118
    NoThru22

    NoThru22 Smelly Pirate Hooker

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    This was an unecessarily mean response to the poster's comment. I was thinking along the same lines and I'm sure a lot of people too timid to post were also thinking the same. I'm sure your tangents are not discouraging anyone with useful information from actually posting, but there was no need to lash out at the poster like that.

    That being said, the question hasn't been answered, the answers aren't here, and a lot of people are still curious. This isn't the best place to ask because (1) this is the Tivo forum and the new HD box isn't a Tivo and (2) the existing mpeg4 box isn't even a DVR yet! I will try to search other forums and find an answer to quote or link to.
     
  19. Dec 28, 2005 #39 of 118
    NoThru22

    NoThru22 Smelly Pirate Hooker

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  20. Dec 28, 2005 #40 of 118
    Jimmmmbo!

    Jimmmmbo! Eh? I don't get it.

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    Thanks for the link, Nothru22. Your two points are well taken, and much more elegantly stated. :up:
     

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