Calibrating HDTV using HTPC as display device.

Discussion in 'Home Theater PCs' started by SlitheryDee, Jan 16, 2017.

  1. SlitheryDee

    SlitheryDee Lifer

    Joined:
    Feb 2, 2005
    Messages:
    17,221
    Likes Received:
    9
    So I'm trying to calibrate my LG OLED65B6P using the HTPC attached to it, and I'm running into some curious issues in the process. I was wondering if the forums could provide some insight as to what's going on here.

    I'm using a calibration bluray disk called Digital Video Essentials: HD Basics to guide me through the process. The disk is being played from the internal blu ray drive in my htpc using cyberlink powerdvd with all of cyberlinks image enhancement features turned completely off.

    The first hurdle I encountered was in the PLUGE pattern used to set the black level of the TV. There is supposed to be a light square in the middle with three bars of varying levels of "blackness" to each side of it like in the following picture.

    [​IMG]

    Initially I couldn't see darkest bars on the outside edges of the image. All that appeared no matter what my brightness setting was was the two inner bars against a grey background with the lighter rectangle in the middle. After mucking around a bit in my graphics card settings I found that changing the color space to ycbcr444 (from ycbcr420) allowed me to see all the bars when played through powerdvd. Great. All the other test patterns seemed to work as they should. I did notice that the picture seemed just a bit too dim for my tastes afterwards though.

    Next I decided I wanted to rip the test pattern track from the disk to my plex server so I'd have it on hand to calibrate any tv in the house. Got that done, only to be faced with the same issue again. The outermost bars are once again invisible and the black level is suddenly too low. Playing the track from my plex server through the plex player and playing it back directly from the pc using vlc and windows media player all yield the same result. I went ahead and recalibrated using this video anyway, reasoning that since plex was probably going to be my main method of playing video anyway, the tv should be calibrated to whatever best suited plex. It should be noted that the brightness level seemed better to my eye when calibrated from the ripped track.

    I'm flummoxed as to why I can't get all the black and white information to display from the ripped track while playing directly from the disk seemed to transmit it though. What is cyberlink powerdvd doing that isn't being done by plex, vlc, or media player? I've already tried messing with the video quality settings in the NVidia control panel to no avail. There is a selection for limited or full dynamic range there that seems to make no difference whether it's on or off, and none of the other sliders will make the missing bars appear on the PLUGE pattern. I feel that the last bar is pretty important too, because it is the one that is supposed to be "blacker than black" allowing me to really find exactly where my tv must be set to get true blacks with maximum detail by lowering the brightness until it just barely disappears.

    It appears that both "blacker than black", and "whiter than white" information is missing when I play the track through plex or any other media player, because the white level calibration pattern is missing detail at the highest range as well. This tells me that for some reason the signal is being "clipped" at both ends, but I can't for the life of me find a setting that stops this from happening either in my tv or in my HTPC. Anyone know what's causing this issue?
     
  2. Loading...

    Similar Threads - Calibrating HDTV HTPC Forum Date
    Well that was unexpected, HDTV screen blinking with RX 470 Home Theater PCs Mar 27, 2017
    Razer Turret for HTPC use Home Theater PCs Mar 12, 2017
    Last generation of graphic cards with HDTV s-video? Home Theater PCs Jan 23, 2015
    DVI-I or VGA to Component HDTV y/pr/pb doesn't work why? Home Theater PCs Jan 22, 2015
    HDTV Tuner for Amazon Basics 50ft/35ft Antenna and Other Questions Home Theater PCs Oct 3, 2014

  3. Smoke

    Smoke Distributed Computing Elite Member
    Super Moderator

    Joined:
    Jan 3, 2001
    Messages:
    12,551
    Likes Received:
    79
    SlitheryDee, I have an LG OLED65E6P as well as the old Digital Video Essentials.

    I just called LG TS and discussed this with one of their 1st line agents. The TS agent suggested that the output from DVE via the HTPC is not compatible with this new tech TV resulting in what you have experienced. I suggest you call their TS and ask for the VIP TS Department later in the day when they are open. The 1st line agents work 24/7 but the VIP section is only open 9:00 AM to 6:00 PM CST.

    The VIP Department specialize in the new OLED 4k TVs and provide more advanced support.
     
  4. SlitheryDee

    SlitheryDee Lifer

    Joined:
    Feb 2, 2005
    Messages:
    17,221
    Likes Received:
    9
    Wow thanks for that. I shall certainly give them a call.

    I don't understand what "not compatible with this new tech tv" could mean though. My htpc is running a gtx1070, which supports the latest HDMI and HDCP standards AFAIK. I have HDMI Ultra Deep Color turned on for the port that the htpc is connected to, which is what allowed me to set the color space to ycbcr444@4k60 in the first place. They seem to match up pretty nicely from a standards perspective. I really don't think it's a problem with the tv at all, but rather some setting or combination of settings within the HTPC that I'm missing. Hopefully they can help me with that.
     
  5. Smoke

    Smoke Distributed Computing Elite Member
    Super Moderator

    Joined:
    Jan 3, 2001
    Messages:
    12,551
    Likes Received:
    79
    It is my understanding that the only company that is currently manufacturing 4K OLED TVs is LG Electronics although Panasonic is supposed to start producing them sometime this year (2017).

    Staying on topic, I do own the calibration bluray disk called Digital Video Essentials: HD Basics. I have owned it for many years. I believe the best way to get the absolute best picture on your 4K is to have it "calibrated" by a $$$ professional, but as always YMMV. ;)
     
  6. Fallen Kell

    Fallen Kell Diamond Member

    Joined:
    Oct 9, 1999
    Messages:
    4,978
    Likes Received:
    7
    That is because the process of ripping and importing into a plex server re-encoded the video to a new format.

    Again, it all comes back to the re-encoding. It is also possible that your plex server is transcoding it on the fly. Remember that you need to also make sure your computer understands it is connecting to a TV and not a monitor (otherwise you will be dealing with the standard TV's think black is 16 but the computer thinks it should be 0). It is also highly possible that the TV will detect that a computer is connected to that particular input and will process the video as though it was expected to be a monitor. (I think it was in the one of my first LCD TV's that they put something like that into it, luckily you could change it from auto-sensing to manual).