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Picture quality issue ...

Discussion in 'DIRECTV General Discussion' started by Janice805, Nov 18, 2010.

  1. Janice805

    Janice805 Legend

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    Nov 26, 2005
    I've had a Sony 52XBR4 (LCD) as my main TV for several years now. I purchased (great deal from Costco) a Panasonic TCP54G20 (plasma). I have both going at the same time (out from my HR24) for testing. I'm new to the plasma world so I have a question.

    My 52XBR4 is a GREAT TV and so it seems is the new plasma also, but, I thought that a "plasma" wouldn't have motion issues. I don't know how to properly explain what I'm trying to say. Sometimes on my LCD there are "slight" problems with fast motion, when strobe lights go off in a scene, or other. Anything from a fast blur, to fast, quick "blocks" if you will.

    Anyway, having both side by side and running all day for comparison I've discovered any picture disturbances that I've (tried) to explain are happening to BOTH sets. Now, maybe my LCD was a pretty good set and the plasma didn't solve anything.

    Is what I'm describing a Direct TV signal issue?
     
  2. Hdhead

    Hdhead Hall Of Fame

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    Nature of the HDTV beast. Directv is broadcasting in full HD so it is not them. Digital artifacts are still common in situations as you describe. 720p or 1080p handles it much better than 1080i. I also have a plasma and several LCD sets and see the same thing.
     
  3. harsh

    harsh Beware the Attack Basset

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    If you're seeing it on both TVs, it probably isn't the TVs.

    Unless you also have an AM21 to compare local broadcast with what DIRECTV delivers, there's really no way to confirm whether the problem lies in the encoding or the HR24 itself.

    It seems likely that it is an encoding issue. Knowing what channel(s) you're observing the symptoms on may help others to corroborate (or isolate) your symptoms.
     
  4. harsh

    harsh Beware the Attack Basset

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    This is entirely flawed reasoning. DIRECTV is applying all sorts of black magic (contouring) to the HD signals that they deliver.
     
  5. Janice805

    Janice805 Legend

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    Nov 26, 2005
    I'm doing a lot of channel surfing. I've been trying to compare for a week now. I "thought" the plasma would solve the issues I've seen with fast action. Again, testing both at the same time on the same receiver, I have to wonder about the signal. I watch "some" SD (little as possible), but watch mostly HD broadcasts. By the way. Since the HR24 has only 1 HDMI out, I've had to use the Component Video out to the other TV. But, in case anyone asks, I've switched the HDMI/Component between both TV's so the problem is not the connection method.
     
  6. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    Not sure exactly what you're seeing, "but" might suggest it comes from the MPEG-4 being transcoded on the fly [real time] from the MPEG-2 feed.
     
  7. sx2700

    sx2700 New Member

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    Jun 20, 2010
    I have an old Panny PTV that is 10 years old but it does HD extremely well. It is starting to show its age and is getting some blurring on the edges. I've replaced the convergence chips and the associated resistors once already, but I would like to get something newer and I'm hesitant to pull the trigger because of issues like the OP is reporting. I have no ghosting or trailing or whatever it's called with my PTV now. I will be very interested to hear what others here have to say on this issue.
     
  8. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    I had a Sony HD RPTV [my only PTV] and moved to an XBR LCD. I'll never go back to a PTV.
    Some like Plasma and I'll leave them to praise theirs.
     
  9. Hutchinshouse

    Hutchinshouse Hall Of Fame

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    Sounds like both TV’s are equally displaying the limitations of satellite TV. I know exactly what you’re talking about. Faster moving scenes require more bandwidth. I’ve seen the very same issue during strobe lights or fast moving scenes. Yet, I don’t see the issue via blu-ray. I too have the 52XBR4

    Feed both TV’s a high quality blu-ray. See if ya see the same issue.


    The problem is TV quality surpasses provider's quality. Sure, one TV may be fast than the other. However, you may not see a difference if the source stinks.
     
  10. BattleZone

    BattleZone Hall Of Fame

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    What you are seeing are digital compression artifacts.

    If 1080p video was "raw" (uncompressed), your HD-DVR would only be able to hold a few minutes of video, because the amount of data is huge. In order to be managable, video is compressed, using "lossy" compression. This means that data is removed/lost as part of the compression process to help lower the size/bitrate needed to store/transmit the data.

    When you are watching programming where most of the screen isn't moving or changing from frame-to-frame (think of most news shows with "talking heads" on a fairly static background), the amount of bandwidth needed is low, because the video can be compressed easily without losing much "real" data. But when every pixel on the screen is changing from frame to frame, the bandwidth required to keep track of all of that data goes way, way up. In fact, it goes up higher than the bandwidth that the carriers can provide, and higher than the compression codec can compress without visible errors. The result is "macroblocking", which is a form of compression artifact. That's the square "tiling" you see during fast motion.

    DirecTV allocates about 8-9 Mb/s of bandwidth for each HD channel, on average. That's just enough that *most* video looks okay. To compare, a Blu-Ray disc can have sustained bitrates of over 40 Mb/s, and peak at 50 Mb/s. That's more than 5 times the bandwidth than DirecTV. All that extra bandwidth is used to reduce macroblocking and other compression artifacts (like washed out color due to color depth reduction). DirecTV could transmit at the same bitrate, but they'd have to drop 4 out of 5 of their HD channels to do so, and that's obviously not going to happen.

    By comparision, on Uverse, in areas that can get 3 HD feeds, the HD channels only get about 5.5 Mb/s of bandwidth, and the negative impact on picture quality is readily apparent.
     
  11. Janice805

    Janice805 Legend

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    Nov 26, 2005
    OK, just took a picture of the two screens with what I'm talking about. How do I insert a picture here?
     
  12. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    1Capture.PNG
     
  13. Janice805

    Janice805 Legend

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    VOS, the box I'm replying in doesn't have all the options you just posted
     
  14. Janice805

    Janice805 Legend

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    Nov 26, 2005
    Oops, have to hit GO ADVANCED. Never notice it before.
    Let's see if I can post this picture.
     

    Attached Files:

  15. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    "or " click quote and not quick reply. :lol:
     
  16. Janice805

    Janice805 Legend

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    OK, there's the picture. You just see some "blurring" or "distortion" while watching live, but I paused it, then went frame by frame, and walla. What the heck.
     
  17. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    Yep, that's really bad.
    Sure looks like the weakness of MPEG-4 being transcoded on the fly.
    MPEG-4 can be great, but it is best when it's not done in realtime, as the bit-rate can increase to much higher levels.
    1080p VOD is not done on the fly and can peak well above 25 Mb/s, which the SAT feed has a hard time doing realtime.
    MPEG-2 most likely would have "some" of this too, but not anywhere near as bad.
    I seem to remember seeing the fans in the background becoming "blurry", but not the foreground image.
     
  18. Janice805

    Janice805 Legend

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    OK, so the plasma wasn't the answer. I mean I would have to suppose must of you get this too???

    If not, what's the answer, what do I do to make this better? By the way, I appreciate all the responses. Have to run my mom to the doctor right now. I'll check your posts/suggestions when I get back.
     
  19. lesz

    lesz Legend

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    Aug 3, 2010
    I'm not sure that the picture you posted is helpful in evaluating the issue about which you are concerned because, unless your camera is using a shutter speed faster than the frame rate of the TVs, the picture is actually going to contain several frames of video contact and, if there is action on the screen, it is going to be blurred regardless of whether there is blur in actual viewing.

    I also am guessing that the earlier poster which talked about the difference between 720p and 1080i picture content is getting close to reason for your issue. Are you seeing the blurring on both 720p and 1080i programming? Many will see no such blurring with 720p, but, with 1080i, because you are actually seeing two adjacent frames simultaneously, the blurring will often be noticeable with scenes containing action. Newer and higher end LCD TVs reduce these effects by increasing the refresh rate. With older and lower end sets, the refresh rate is likely to be 60 Hz per second, and you are more likely to see the blurring. Newer sets are more likely (but not necessarily) using refresh rates of 120 Hz or 240 Hz. You should be able to find the specs for your set somewhere in the manual.
     
  20. Hutchinshouse

    Hutchinshouse Hall Of Fame

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    FYI - The video was paused. Shutter speed not an issue.

    I think there’s more to it than refresh rate. The OP’s plasma has the very same issue. Plasmas have a smoking fast refresh rate.

    My recommendations:
    1. See if problem can be duplicated using blu-ray
    2. Try a 2nd receiver. Perhaps the receiver is toast.
     

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