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DirecTV Compressed Quality and Compression Artifacts

Discussion in 'DIRECTV Programming' started by kenkraly2004, May 17, 2010.

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  1. kenkraly2004

    kenkraly2004 AllStar

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    I notice especialy with movies that Directv has a lot of Compression Artifacts and it happens a lot compared to a blu-ray disc. Why is that is it due to limited bandwith from Directv?
     
  2. texasbrit

    texasbrit Well-Known Member

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    Blu-ray has a peak bandwidth equivalent to at least 4x the effective bandwidth available to DirecTV, or indeed any of the satellite or cable providers, for real-time channels. 1080p Movies that DirecTV downloads to your DVR can use higher bandwidth than real-time channels but still won't approach blu-ray. .
     
  3. BattleZone

    BattleZone Hall Of Fame

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    No TV distribution system, not cable, satellite, or fiber, has the bandwidth of Blu-Ray. Not even close.

    Blu-Ray generally uses MPEG4 compression (a handful of early discs used MPEG2, but virtually all Blu-Rays mastered in the last 2 years have been MPEG4/AVC), and can run 40 Mb/s continuously with peaks up to 50 Mb/s! DirecTV's HD is among the highest for TV providers, and runs about 8 Mb/s of MPEG4, which is 1/5th of the bandwidth of Blu-Ray. FIOS has more bandwidth (up to 19 Mb/s), but uses much less efficient MPEG2 compression, which means it is about the same quality as DirecTV. Uverse's HD is as low as 5.5 Mb/s, necessary to squeeze 3 HD streams & 1 SD stream in the data pipe originally designed for 4 SD streams.

    Not only is there nothing currently that comes close to Blu-Ray's bandwidth, but there are no TV distribution systems even PLANNED to match it. It is very unlikely that you would see any such system within the next 20 years. And that's why Blu-Ray is king. A local player doesn't have to be concerned with all of the problems of distributing such high bitrate data streams; you just drop in a disc and go.
     
  4. kenkraly2004

    kenkraly2004 AllStar

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    Directv in my opinion compress'es it's HD Bandwith too much and their bandwith will never come close to a what's blu-ray disc.
     
  5. Hoosier205

    Hoosier205 Active Member

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    ...they compress it less than any provider other than Verizon Fios. Of course it won't come close to blu-ray quality. That isn't even possible with current cable and satellite technology.
     
  6. tonyd79

    tonyd79 Hall Of Fame

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    Actually, they do not compress at all. They transcode from MPEG2 to MPEG4 but they do not compress.

    "too much?"

    That is a matter of opinion, but no one is broadcasting at the rate of blu ray. It is not workable and is beyond the broadcast standards.
     
  7. Stuart Sweet

    Stuart Sweet The Shadow Knows!

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    Tonyd79 is right, where HD channels are concerned. With SD channels, sometimes the source material is compressed or bitstarved a little.
     
  8. tonyd79

    tonyd79 Hall Of Fame

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    Oh, I agree with that. Although having been a Comcast and Fios customer alongside DirecTV in the last year, DirecTV SD is not that much different than they are. Most SD is unwatchable on a large HD display.
     
  9. kenkraly2004

    kenkraly2004 AllStar

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    Good points by everyone.
     
  10. BattleZone

    BattleZone Hall Of Fame

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    That isn't correct. DirecTV both transcodes MPEG2 content into MPEG4 (though some providers, such as HBO, will deliver their content via MPEG4), AND compresses the feed. All multi-channel providers do this except FIOS, but as I pointed out, FIOS is all MPEG2, so they need more bandwidth than DirecTV does to deliver an equivalent picture quality.

    DirecTV does not reduce the resolution (number of pixels) of their HD content as some other providers do, and as they used to have to do for their MPEG2 HD channels. Perhaps that's what you're referring to.

    DirecTV does reduce the resolution of the SD channels, from a max of 720x480 down to 480x480.
     
  11. Avder

    Avder Hall Of Fame

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    Blue Ray is to High-Def Digital Cable as DVD is to standard Digital Cable. Both discs are incredible improvements as far as quality over their terrestrial counterparts. DirecTV is significantly better than HD Digital Cable, but still far from the quality of a blue-ray disc.

    Depends on the source material too. For instance, animation lends itself much more to being compressed than live action does. And also some content creators might not send the best signal to DirecTV, so any decrease in quality there will be mirrored in DirecTV's feed of it, and thus any NBC/Universal channels 1080i gets blown out by every other 1080i channel on DirecTV.
     
  12. gregjones

    gregjones Hall Of Fame

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    And as has been noted on dozens of occasions, there is no way to measure the impact of that transcoding except in the number of pixels different from the source (in this case the MPEG2 feed from the uplink) to the output.

    It is possible to have a stream be compressed (bandwidth lower by 30%) with only 5-6% pixels different. This is one of the primary advantages of the compression employed by DirecTV and others versus the older compression used by ATSC standards.

    Is it the same as Blu-Ray? No. Is FIOS inherently better because it is MPEG2? No. Ideally, the upstream providers would give DirecTV an MPEG4 feed, allowing a cleaner, less lossy stream. But to all but the most critical viewer, the difference between FIOS HD and DirecTV HD will be minimal.

    Many of the "compression artifacts" I have helped diagnose on friends' setups are due to their viewing SD material, a station that upconverts content poorly (TBS) or a horribly misguided setup (setting the HR20 to output 1080i only on a 720p native set).
     
  13. Tom Servo

    Tom Servo Icon

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    All's I know is I remember the picture quality of the MPEG2 channels in the 70's, and that the MPEG4 versions of those channels that launched later were not as good when it came to macroblocking. But it wasn't a big enough different to really kvetch about.

    Those same channels now exhibit a lot more macroblocking that before, as do all the new additions. Even Travel Channel had some moments that look really awful during one of their upconverted shows about water parks. A babbling brook turned into a blocky mess. I'm 99% sure that isn't how it looks at the source, upconverted or not.

    Plus, I've seen that same episode in SD off cable in another city and those artifacts weren't present anywhere. So it is definitely the compression D* is using. Oh well, "at least they aren't downrezzing." Yet. (Yeah, I'm a pessimist. :p)
     
  14. Hoosier205

    Hoosier205 Active Member

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    They use less compression than Dish and just about any other provider as well...with the exception of FIOS.
     
  15. tonyd79

    tonyd79 Hall Of Fame

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    Huh? I remember the opposite. I also remember the opposite for the vast majority of posters here who celebrated the coming of MPEG4 when D10 went live.
    Again, huh?

    I think you have a problem with your install. Are you sure your signal levels are good? It is possible the water parks picture messed up (as you said, it was upconverted) but generally the MPEG4 channels are solid.
    [/QUOTE]
     
  16. Carl Spock

    Carl Spock Superfly

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    And sometimes much more than a little. I watch C-SPAN a fair amount and it is compressed beyond belief. I realise you don't need much bandwidth for talking heads, but at least give C-SPAN enough headroom so that men's ties don't come in and out of focus every time they move, will ya, DirecTV?

    (I just had to make a correction in the above paragraph. I wrote "badwidth" instead of "bandwidth". Actually, when it comes to C-SPAN, I think I got it right the first time.)
     
  17. Tom Servo

    Tom Servo Icon

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    Being the best of a bad bunch is not necessarily a compliment. :p

    I feel like the color depth actually improved, as did some of the handling of some motion scenes. But as far as blocky motion on certain channels, I think things have gotten worse over time. Whether that's D*'s fault or the signal provided to them has gotten worse, well I dunno. HDNet is a good example. It really pales in comparison to say, MGM HD or MSNBC. Both of those really look spot on so far. But whereas when MGM HD debuted, it looked stunning and almost artifact-free, now it too suffers from the occasional blocky scene. And this is just film we're talking about, there's no reason something converted from 24 fps should look bad, ever.

    Signal levels are irrelevant to macroblocking, only pixelation (where the actual picture breaks up). I don't have that problem. Well, I have audio dropouts and occasional picture hiccups but oddly those don't bother me much.

    If nothing else, can we all agree that the SD picture on D* is just horrible compared to how it was a decade ago? ;)

    Upconverted OAR on channels like MTV and WGN look like the SD did back before they offered locals. Edges were sharp, colors were deep and nary a frame was skipped. Now it's almost down to YouTube quality.
     
  18. Carl Spock

    Carl Spock Superfly

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    I'll give you a Sunday morning AMEN! shout out.
     
  19. Paul Secic

    Paul Secic Hall Of Fame

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    HD-LITE!:lol::lol::lol::lol::lol:
     
  20. GregLee

    GregLee Hall Of Fame

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    Oh, my. I have two 720p Samsung plasmas (actually 728p internally), and I thought 1080i-only was a reasonable setting. That's what I use now for my H21, though I think the native setting looks slightly better for SD on my HR20.
     

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