beta HW accel fixed, but...

Discussion in 'Issues and Bugs' started by dbG33K, Mar 29, 2018.

  1. dbG33K

    dbG33K Member

    Upon installing the most recent CloneBD beta I was thrilled to find that HW acceleration is fixed for my problem UHD ISOs. There's no longer artefacting or skipping/delayed frames.

    However, now that I've had a chance to complete an MKV, it seems the HDR is not resolving to SDR properly. The resulting video is very pale or washed out compared to playing the ISO in a capable player such as DVDFab Player 5.

    I've attached a few screenshots to demonstrate. After one shot from VLC of the finished MKV, and one shot from DVDFab Player5 off the ISO (before running through CloneBD), it looked like maybe just brightness was off. So I corrected the VLC screenshot to match brightness, and it's evident the colors are not as vivid after CloneBD converts the ISO into an MKV file.

    To repeat from my previous thread, my problem UHD ISOs are:
    The Mummy Returns (The Mummy Ultimate Trilogy (US)" set)
    The Hunger Games (from The Complete 4-Film Collection)
    The Hunger Games - Catching Fire
    The Hunger Game - Mockingjay Part 1
    The Bourne Identity (from the Ultimate Collection)
    - possibly the other Bourne movies from the set too. Haven't tried them yet
    Split (2016)

    Attached Files:

    Last edited: Mar 29, 2018
  2. Terramex

    Terramex Well-Known Member

  3. dbG33K

    dbG33K Member

    Looks very similar to VLC. Again brightness difference, perhaps, but doesn't look as vibrant as DVDFab Player 5 playing the ISO directly
  4. Reto

    Reto Elaborate Bytes AG

    In order to compare, it doesn't help using different players.
    Can you post a screenshot from both sources in the same player?
    HDR to SDR conversion adheres strictly to ITU-R BT.2087, there's no wiggle room, those are precise formulas and numbers, whereas a player has more freedom in what it does with the picture.
  5. Pete

    Pete Forum Admin Staff Member

    ...also: are you watching on an HDR monitor? In that case the colours would of course be more saturated with an HDR movie, after all, that's the whole point of HDR.
    Especially the studio logos show off HDR brightness and colours so they add to the sex appeal of the new format.
    A better way to compare images would be the actual movie content.
  6. dbG33K

    dbG33K Member

    I'm using an SDR monitor, and the video feed is the Bourne Identity from the UHD Complete Collection, so it should have HDR. Here are the logo screenshot from the ISO and from the MKV made using CloneBD beta. I didn't tamper with either brightness, since they're both from DVDFab Player5. Let me know if you need anything else from me.

    Attached Files:

  7. Pete

    Pete Forum Admin Staff Member

    Yes, of course the source has HDR, that was never in doubt.
    Yes, they look different - to me the MKV looks better, brighter and has more contrast.
    And if you ask me - I know what the UHD-Universal logo looks like on an HDR monitor and your MKV output comes closer to that, than the other one (and more than coming close is not possible, otherwise we wouldn't need HDR at all, converting HDR to SDR is a best effort approximation).

    What do you expect anyone to do, now?

    Obviously, DVDFab does something a little bit differently than CloneBD, when converting HDR to SDR.
    You read what Reto said: CloneBD adheres 100% to the specs. If that is so, then DVDFab player may not - or maybe DVDFab player does something in addition to that - it's a player, they can do what they think is best with the picture.
    Not even the specs on this conversion are the law, they are recommendations.

    As to my observation regarding the MKV version looking better: monitors can be set up for different colour temperatures, brightness levels, contrast - also can have different possible ranges, depending on quality and age.
    It's totally possible, that on your specific monitor the ISO version looks better, I can't tell from your screenshot what it looks like on your monitor.
    On both of mine here, the MKV version wins.

    Also, I say again: you should better compare actual movie content - after all, you didn't buy the disc to watch the studio logo, which has also been artificially boosted to blow away viewers with excessive brightness on HDR monitors.
  8. dbG33K

    dbG33K Member

    Thank you for taking a look. I wasn't really expecting anyone to do anything. Just needed a knowledgeable set of eyes to look at the screens and let me know one way or the other. You're obviously far more familiar with HDR and the result of it brought back to SDR than I am, so I trust your eye and your judgement.

    I'm sorry for taking up your time. Just wanted to make sure I was getting as much out of my equipment as possible ;).

    Thanks again.