RGB input on rptv

Discussion in 'Displays' started by EddieMata, Feb 26, 2005.

  1. EddieMata

    EddieMata Agent

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    I have a Pioneer SD-533hd5 rptv, which has a RGB input jack (15pin type). The manual states that it inputs 5 signals, R,G,B,H,and V, from digital tuners and "the like." It also states that shouldn't be use for pc or other devices.

    Could this input be some had used with DVI via an adaptor? Or are there possibly any upconversion DVD players that would have this output? And could it even be used as such other than a digital tuner? Just wondering what I could possibly use this input for in future?

    Thanks for any information!

    Eddie
     
  2. Allan Jayne

    Allan Jayne Cinematographer

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    RGBHV and also VGA, SVGA, etc. are analog signals.

    You need to find out the allowable "scan rates" aka "resolutions" that input is meant to accept. The TV's manual should say so.

    480p progressive scan NTSC, when in RGBHV (as opposed to Y/Pb/Pr) form, is for all intents and purposes the same as computer regular VGA.

    Video hints:
    http://members.aol.com/ajaynejr/video.htm
     
  3. ChrisWiggles

    ChrisWiggles Producer

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    You could hook up an HTPC very easily, without having to convert the format into something else. Some users, like myself, have displays that only have RGB input. I use a computer to drive it.
     
  4. Seth Paxton

    Seth Paxton Lead Actor

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    Yes, I think at least one issue with "don't hook up a PC" is the resolution level and the tolerance for scan rate changes (we think nothing of altering scan rates on those kick butt monitors that can sync over a whole range easily).

    The pixel structure and scan rate/resolution might not be considered adequate for PC display. Also there would naturally be concern over burn in with a PCs static picture.

    But I've seen several sets with 2 VGA inputs where one is "not for PC use", and that indicates to me an issue with scan rate tolerance or something.


    Anyway, cross-convertors are pretty common (Audio Authority makes some still I think) and somewhat cheap now. These go from Component (Y Pb Pr) to VGA (RGB H and V) or vice versa. I supppose someone might build something as complex as a DVI to analog output (either VGA or YPbPr) but since DVI is not the sort of output to be exclusive to a device (meaning no other option as an output) I'm not sure that anyone would bother to make one, at least for very cheap.


    With an HT PC, the key is just to mate it well with the set, make sure the signal it puts out are the sync/resolution that are optimal/acceptable for the TV scan rate and sync circuit. As said, in the manual.

    You wouldn't be upconverting as VGA (480p) is not a higher resolution than DVD Progressive (same thing as said) nor is the scan rate/sync faster. 480 lines of video info coming every 1/30th of a second.

    Its just a difference in how that info is carried. Each color with its own full space and with the sync signals separate, or with the syncs packed onto the Y which is basically the B&W of a signal with 2 color difference signals as well (Pb Pr), done to reduce waste in info space (RGB end up carrying redundent B&W info).

    Apart from whatever issues occur when mixing data the bottom line is both YPbPr and RGB are carrying the same video info, same rez, same rate in this application.
     
  5. EddieMata

    EddieMata Agent

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    Thanks for all the information ya'll!


    So if I setup a digital tuner via that RGB input, will it not be true HIDEF?
     
  6. JeremyErwin

    JeremyErwin Producer

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    My Samsung set top box outputs 720p and 1080p via the rgb port. I currently have a SVGA monitor hooked up to it in 720p mode, though whether I'm getting HiDef through it is anyone's guess-- the monitor indicates it's using a "user defined" resolution (45KHz horizontal frequency, 60 Hz vertical)

    Ah! In 480p mode, it uses a Hf of 31.5 KHz, and Vf of 60 Hz. Divide Hf by Vf and one gets 525. I'm pretty sure that means something...

    Likewise, 1080i has a Hf of 33.7 Khz and a Vf of 60 Hz, producing 562.5 lines. (interlaced...).

    That 720p uses about 750 lines. And it also means that the samsungs letterboxing reduces my effective resolution to 540 lines of picture. (argh! Perhaps the vertical squeeze trick will come in handy).
     
  7. Allan Jayne

    Allan Jayne Cinematographer

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    480p has 480 scan lines of picture (480 active scan lines) and in its analog form 45 additional scan lines to hold sync. information and give time for the electron beam to return to the top of the screen. Total 525 scan lines.

    720p analog video has 750 total scan lines. 720p U.S. HDTV is normally 16:9. Only inferior 4:3 HDTV TV sets display 720 scan lines over the entire screen all the time requireing letterboxing that downconverts the picture to occupy 540 scan lines.

    1080i analog video has 1125 total scan lines, 22-1/2 scan lines after each 540 line field for the sync. info as described above.

    During digital transmisssion/processing and for storage digitally the extra scan liens (retrace intervals) are not included so the terms 480p, 720p, and 1080i are still technically correct. The retrace intervals are recreated if and when the video needs to be put in analog form for example as Y/Pb/Pr component video.
     

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