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20.3.8 Release Notes

Discussion in 'TiVo Roamio DVRs' started by TiVoMargret, Dec 12, 2013.

  1. HarperVision

    HarperVision TiVo's Italian Cuz!

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    It is, it's called the "vertical blanking interval" and that's where information/data is inserted in TV signals.
     
  2. cosmicvoid

    cosmicvoid Tivo noob

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    You mean "used to be inserted" in analog NTSC, as digital signals that the Tivo handles do not have VBI.
     
  3. morac

    morac Cat God

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    I haven't seen them for a long time, but the digital signals used to have VBI signals in them back when analog was being converted to digital. With most signals now being digital along the entire path from encoding to playback, VBI I'd agree with you.
     
  4. HarperVision

    HarperVision TiVo's Italian Cuz!

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    Yeah, I'm showing my age I guess, but I still do see the data when I have an under scanned image.
     
  5. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    I found a way to set my TV to full pixel mode. Not sure why TVs still use an overscan area for 16:9.
     
  6. nooneuknow

    nooneuknow TiVo User Since 2007

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    Cox Cable...
    To help insure that the people who buy them don't return them, if they see the noise that would otherwise be pushed off the edge of the display area (in 16:9 mode w/auto overscan), and find it annoying/distracting.

    Also, if you were in a showroom full of TVs, and some had a bezel obscuring that noise, in full-pixel/just-scan mode, you may be inclined to buy a TV that simply has a bezel that covers more of the LCD/LED panel, than one that doesn't obscure/overlap the panel.

    You have to have the knowledge, as a buyer, to know what the deal is, and the TV makers can't count on that. So, they default to a way where unless the store changes each and every display's settings to full-pixel/just-scan, none of the display units will be showing the whole picture, in a true native mode.

    It's still a downside, for those looking for the best picture, since the best picture isn't displayed with the added overscan to hide any potential noise along any edge.
     
  7. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    That "noise" is the VBI signal and only exists on analog stations. Since analog can't be 16:9 it makes no sense to make the 16:9 mode use over scan. 4:3 sure, but 16:9 can only come from a digital recording and digital recordings store captions digitally not as VBI. The only exception I can think of is DVDs. Some DVD players will convert the digital captions to VBI so the TV can display the captions. However most DVDs use subtitles, not NTSC captions, so this would be really rare.
     
  8. HarperVision

    HarperVision TiVo's Italian Cuz!

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    Analog can be 16:9 if it's squeezed horizontally and then stretched back out in the display, aka anamorphic.
     
  9. nooneuknow

    nooneuknow TiVo User Since 2007

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    This discussion is kind of drifting the thread off topic, but...

    Unless Cox is falsely representing analog as 16:9 HD digital, then I have to "disagree" (if that's even the right word).

    I see the top "noise" dancing around on HD stations, especially local rebroadcast stations, even more so on those that are broadcast in 720P, and often see slim, light, side edges when the picture is dark, or is dark at the sides. It doesn't matter which TV I use.

    It's not bothersome enough for me to revert back to the default 16:9 overscan, but is for others I personally know. So, YMMV, etc.
     
  10. HarperVision

    HarperVision TiVo's Italian Cuz!

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    From what I recall from my broadcasting days early on in the digital transition then the VBI information was removed and embedded into the digital signal but it had to be regenerated at the receiving end for any older equipment that still may be in the loop. Maybe that is what is still going on?
     
  11. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    DVDs are the only thing that are anamorphic and they store captions digitally too. Although in some cases DVD players will create a VBI from the digital captions for support on older TVs. However very few commercial DVDs actually have real NTSC captions, most of them just use a subtitle stream instead.
     
  12. nooneuknow

    nooneuknow TiVo User Since 2007

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    Could be. I don't know enough to really contribute any further, and I'd like to let the thread get back on-topic. The AVS forum seems to be the best venue for everybody to learn from, and ask questions in. It's getting pretty speculative, and old-tech vs. new-tech in this venue.
     
  13. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    Cox must be doing something weird then. HD does not use VBI. In fact HDMI does not even support VBI so even if it was in the stream your TV wouldn't know what to do with it on the HDMI input. Some cable boxes will generate a VBI signal and lay it onto the video if they're set to analog output (even component) but you shouldn't be seeing that with TiVo because it doesn't do that. It has an internal caption decoder, so it just decodes the captions itself and overlays them on the video stream.

    Are you saying that with a TiVo, connected via HDMI, you're seeing the VBI flicker along the top edge and the faded edge down the left like you would on an old analog recording even on HD channels?
     
  14. nooneuknow

    nooneuknow TiVo User Since 2007

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    Yes, exactly. It also wouldn't be the first time I've discovered Cox providing "Fake HD", if that is the case, and likely won't be the last.

    I just did a check, and channels that are cable-only tend to have nothing at all at the top, or even the thin light edges at the sides. If the channels are anything that any Cox area in my market could be pulling from OTA and rebroadcasting, the thin, light, edges and dancing top lines are there.
     
  15. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    Maybe they have some old equipment in the loop for OTA. Something leftover from the analog days.
     
  16. CoxInPHX

    CoxInPHX COX Communications

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    Cox does have quite a few channels SD and HD that are not quite centered, there is a small black bar (or noise) on both the top and left side, when overscan is not used, at times it is quite distracting. All of the HBO HD channels have a black bar across the top.
     
  17. gonzotek

    gonzotek tivo_xml developer

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    Now that you've changed your overscan mode, spend some time scanning your channels(HD and SD), esp. the broadcast networks. I'm betting at least a couple will show the VBI bar. I see it on a few channels here in Comcast-land in S. NJ. Doesn't bother me enough to change the mode either, since if I do change it, I'll tend to forget about it until I notice something getting cut off like you and mrizzo80 did in the Opera Apps.

    Speaking of which, I too was hoping to have favorites pinned outside the Opera Store app, on the Apps and Games Tivo menu. I don't think "I should go to the store" when I want to use something I've already 'purchased' (pinned, favorited, downloaded, installed, whatever :) )
     
  18. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    Nope. Flipped through all the locals and no VBI on any of them. We did just go though a major all digital conversion here, so maybe they did before that and I just never noticed.

    But I guess if there are enough places that do still have that then it would explain why cropping the overscan is the default.
     
  19. HarperVision

    HarperVision TiVo's Italian Cuz!

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    Not true. Laserdiscs had anamorphic video and they were composite analog. I've also seen it on VHS tapes and other pro (BetacamSP, etc) tape formats. I've also come across anamorphic broadcast TV where it was in a 4:3 format on the display but you could clearly see it was 16:9 squeezed into it and you would stretch to full width for proper aspect ratio. The original Japanese NHK MUSE Hi-Vision (HDTV) was analog and also had the ability for anamorphic.

    PS - although those are rare, mostly because there weren't enough widescreen AR displays back then.
     
  20. nooneuknow

    nooneuknow TiVo User Since 2007

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    Since you know so much about it, would you like to buy the Pioneer LaserDisc player I have? It's kind of neat. It has a tray-within-a-tray loading system that lets you eject the large tray, or a smaller one to play CDs with. I don't even remember how I got it, but I used to use it to play audio CDs (it still works for that, but I don't have any laserdiscs). :D
     

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