Line doubler in RPTV

Discussion in 'Archived Threads 2001-2004' started by wayne-sun, Sep 10, 2002.

  1. wayne-sun

    wayne-sun Agent

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    I have a 50H82 Toshiba and I have to say that the picture on DVD (component?) input is fantastic. My problem occurs with either sat or cable. On cable I resign myself to the fact the picture will always be substandard but the sat I think should look better than it does. If I use an s-video input to the tv from the sat should the picture be better than the composite (RCA) video? My understanding is the line doubler in the tv is not active when fed by s-video only by composite (RCA)video. Is this correct? I would think that a $3000 rptv could process the signal better than a $50 sat reciever.

    BTW-Not sure if I have component or composite right.
     
  2. Manuel Parrado

    Manuel Parrado Stunt Coordinator

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    The picture will be more color-accurate through the S-video connection since the luminance (b&w detail) and the chrominance (color) will be fed separately to the TV and not combined as in composite video. I'm not sure how much of an improvement you will see, but you should definetely try to get an s-video cable in order to feed the TV the best possible image before the TV digitizes and line-doubles it.

    The line doubler in the TV will be active as long as the signal you feed it is interlaced (as in cable, non-HD satellite, VCR, non-progressive DVD player, etc.). This regardless of whether you feed it throug RF, composite, y/c or component. The reason being that your display is progressive by nature (for non-HD signals) and therefore, the conversion must be made.
     
  3. Allan Jayne

    Allan Jayne Cinematographer

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    Doublers in TV sets are better and better over the years but what you get is still unpredictable. Having 3-2 pulldown (3-2 pulldown sensing and preservation) does not mean the doubler works well with live video (non-film) material.
    In addition, if the TV has only one speed scanning (1080i) an additional conversion is needed for the regular video after doubling. Whereas if the TV does both 480p and 1080i, there are fewer places for problems to crop up with regular video. Going directly from interlaced to HDTV (technically a 240p to 540p conversion) is quite inferior to doing good doubling first (480i to 480p) and then scaling to HDTV (480p to 540p).
    What you really need, but I don't know how to accomplish it, is to audition an iScan external doubler for your S-video. If it turns out your TV is one of those with a not so great doubler, you will see a noticeable improvement and should then go out and buy the iScan.
    Video hints:
    http://members.aol.com/ajaynejr/viddoubl.htm
     
  4. Jan Strnad

    Jan Strnad Screenwriter

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  5. John_Drake

    John_Drake Extra

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    Ok, I'm gonna throw this one out there, since we're on the subject.
    I have a Toshiba 65HDX82.
    I have a Hughes DirecTV Platinum Satellite Receiver (non HD) connected to it via S-Video.
    And I also have a Pioneer 301 Disc DVD Changer connected via Component Video (non Progressive).
    I also have an X-box connected via Component too.
    The Satellite image and X-box appear ok, no real issues, but I seem to have some issues when I play a DVD. Sometimes an area of the picture will "pixelate" or "artifact" for a split second. My wife and daughter think I'm crazy, but I can see it. As an example, I was just watching The Patriot Superbit last night and in one of the battle scenes where the British are riding towards the viewer, their red coats pixelate for a second. This happens with almost every DVD I have played on this set and I must have viewed about a dozen or so thus far.
    I never noticed this with my old Zenith 35" direct view.
    Is this the line doubler of the set screwing up?
    Has anyone else seen this or am I crazy?
    Any thoughts as to how to correct it?
    Thanks,
    John
     
  6. Jan Strnad

    Jan Strnad Screenwriter

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    Something isn't right, or the image wouldn't pixelate. Does the image pixelate at the same spot each time? If so, it could be a scratched disc or a series of scratched (i.e. rental) discs. Since the problem only occurs with DVDs, it could also be your DVD player. In fact, that would be my #1 suspect.
    This SHOULD NOT happen with a good disc and a properly functioning player.
    You might also check the cables by buying a new set (such as a $25 set of AR cables or good Radio Shack cables) and returning them if that doesn't solve your problem.
    I really don't think it's the set, since your other inputs work fine, but then, it could also be a problem with that particular input on your TV. I just don't think it's likely.
    Try another DVD player first, then the cables, and if that doesn't solve your problem, look to the set and get a tech out there.
    FWIW. [​IMG]
    Jan
     
  7. John_Drake

    John_Drake Extra

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    Thanks Jan, I appreciate your input.
    I don't think it's the DVD disc itself. I have them all loaded in the player and I never remove them so they never get handled.
    Also, I have all new Acoustic Research cables (from Best Buy). I have contemplated trying a higher end cable (Monster L3 or Silver Serpents) but I'm not convinced this is the problem either.
    The pixelization occurs mostly on the edge of a subject. It happens real fast and quickly disappears. It seems more prominent with motion.
    After reading the article Allan mentioned above, I'm starting to think that it may be a side effect of the upconversion or line doubling effect. Sounds like the "Motion Artifacting" mentioned in the article. If this is true, others should be seeing it too.
    To add more information about my setup, I have the TV calibrated with the Sound & Vision disc. I have SVM off and the picture set to Film mode.
    I'm thinking of picking up a better component video cable to try and the X-box DVD kit and try playing a disc through that and see if it still happens.
    This artifacting may be occuring with my DirecTV too but I just don't notice because the image is not as highly detailed as with the DVD.
    It drives me nuts.
    Has anyone else seen or heard of this occuring?
    I'm really curious...
    - John
     
  8. Jan Strnad

    Jan Strnad Screenwriter

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    John,

    You have stumped the chump (me). You can always try the Monster Cable, but make sure you can return it if it doesn't solve your problem.

    Maybe a more technically savvy member will be able to help you.

    Good luck!

    Jan
     
  9. ManW_TheUncool

    ManW_TheUncool Producer

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    Is this pixelation happening in places w/ fine gradient color shifts? I haven't watched the Patriot, but the red coat thing sounds like it might be. If so, it's probably just MPEG2 compression artifact you're seeing on the big screen. I see it too in places on my new Panny 53" (w/ non-progressive player) that I didn't really notice on the old 32" direct-view SDTV. It's most obvious to me in blue skies, dark shadows and various primary color near-solids. Often, the artifact looks like solid color banding. Artifacts are also quite noticeable in smoky and foggy scenes like on the original Glory DVD.
    It's the price you pay for going big. [​IMG] This is probably where Jan's approach of going smaller yields better PQ. The only suggestion I can offer is try getting the best DVD player you can afford to see if that will reduce the artifacting. Also, stick w/ top quality DVDs, if you can.
    _Man_
     
  10. John_Drake

    John_Drake Extra

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    Thanks for the comments both of you,
    It's hard to describe it, it happens very quickly, and it isn't always consistent. I've seen it happen mostly on the edges of objects. Kinda like some quick jaggies on say one side of a person's face or arm, sometimes it is more pronounced like on the red coats of the British soldiers in the final battle scene in the Patriot. I agree, It probably is more pronounced on the bigger screen.
    Anyway, I think I have found a solution to make it better.
    I bought one of the Monster Video 3 Component Cables this weekend; the one that says it's certified by the ISF. Last night I warmed up the TV for a half hour, then started to play some DVD's to see if I could notice the pixel problem and it was there. Then, I removed the Acoustic Research cable and I connected the new Monster cable and ran through some scenes from various DVDs. What an improvement!!! The pixel problem seems to be gone! I thought I caught a glimpse of it once in a while and it was very quick, but nothing like it was before. Also, the colors seem more vibrant, especially the greens. Now I have to recalibrate the TV, he he. I was always very sceptical of the expensive cables and I really didn't think it would help, but it would appear that it does. I am going to play around with more this week and see how it goes. I'm also thinking of returning this cable and purchasing the Silver Serpents from bettercables.com instead. I tell ya, seeing is believing.
    I would also tend to believe that there would be even more improvement if I switched to a progressive DVD player or add a line doubler box like the iScan Pro. But, I'm not quite ready to retire my Pioneer 301 disc DVD player yet or invest in a line doubler at this point.
    Maybe I should repost this as a new thread for further discussion since it looks like I took this one over.
    Thanks...
    John
     
  11. ManW_TheUncool

    ManW_TheUncool Producer

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    Were you using the plain AR cables? AR Performance series or AR Pro series?
    I just orderd 2 sets of AR Pro series component cables to replace my existing ones--one for HD STB and the other for DVD. The AR Pro series also uses silver plated copper wires although it might not be quite as good as the Silver Serpents. I ordered them for ~1/2 the retail price from www.accessories4less.com.
    _Man_
     
  12. John_Drake

    John_Drake Extra

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  13. Jan Strnad

    Jan Strnad Screenwriter

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    John,

    Wow. I've never heard of Monster Cable actually making a difference before. I'm glad you were able to solve your problem so cheaply!

    Jan
     

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