[TESTING][S905(X)] 10bit/HDR/Dithering Test Builds & Discussion

    Quote from jd17

    I will test an old Jarvis Marshmallow and your latest Leia test build today to see if the issue is gone in either.

    Leia testbuild: issue present.
    8.0.2e (last Krypton Marshmallow): issue present.
    7.0.3.012l: (last Jarvis, Marshmallow): issue present.

    Unfortunately, all builds show the same issue.
    10bit videos are not being displayed at proper image quality -> double contours.

    As there anything you can do about this?
    Do you want me to provide samples?

    Quote from jd17

    Unfortunately, all builds show the same issue.
    10bit videos are not being displayed at proper image quality -> double contours.

    This is odd, I have a few encodes in HEVC 10bit, some of which I did myself to test picture quality for different settings. Same-bitrate 10bit and 8bit HEVC files from a high quality source are undiscernable (to me, at least) when played on the S905. I most certainly never had any trouble with double contours. Also all European 4k DVB-S2 transmissions are 10bit HEVC, I would have noticed any visible image quality problems.

    Maybe it is something specific to the encode? Did you do it yourself?

    Quote from mmpp

    This is odd, I have a few encodes in HEVC 10bit, some of which I did myself to test picture quality for different settings. Same-bitrate 10bit and 8bit HEVC files from a high quality source are undiscernable (to me, at least) when played on the S905. I most certainly never had any trouble with double contours. Also all European 4k DVB-S2 transmissions are 10bit HEVC, I would have noticed any visible image quality problems.

    Maybe it is something specific to the encode? Did you do it yourself?

    Funny coincidence, I just encoded the same sample again in 8bit to confirm it's a 10bit issue...

    ...just to find out it's not!

    It's an HEVC issue, the 8bit file shows the same blurred contours.

    Yes, I always create my own encodes.
    x265 2.5-4, preset slow, CRF17, no-sao (my standard for transparent encodes).


    Edit: I stupidly compared to the AVC source before.

    My encodes are flawless, indistinguishable from the source.

    The TV's internal media player does not show these false contours (and neither do PC software players) so the root cause is not CRF vs. bitrate.

    I will however recreate those encodes with Hybrid to rule out HandBrake as root cause, but I don't have high hopes.

    This looks like a decoding issue to me.

    Quote from jd17

    My encodes are flawless, indistinguishable from the source.

    The TV's internal media player does not show these false contours (and neither do PC software players) so the root cause is not CRF vs. bitrate.

    I will however recreate those encodes with Hybrid to rule out HandBrake as root cause, but I don't have high hopes.

    This looks like a decoding issue to me.

    I sometimes encode the video myself (x265 HEVC using Handbrake, usually CRF) and never had any issues. Most of them are DVDs though. Is it possible to upload some of your HEVC encoded videos (short excerpt both 10bit and 8bit) for us to test and make sure that it's not a hardware problem?

    I fear you might be misinterpreting the degree, which is probably why you think there is no issue - I would have reacted the same way.

    To make this clear, I am talking about a subtle issue, that you will probably not notice from common viewing distances to your TV, depending on the TV's size of course.

    I myself only really noticed it when I looked for improvements from that NR off command.
    I merely had suspicions before that.

    You need to get close to the TV and compare to a player that does not have that HEVC decoding flaw (TV's internal player in my case).

    Only when you have that comparison you will really notice.


    The best way to see it is high contrast straight edges, like from colored text - this is where I noticed.
    I will try to find a good example and encode a short sample for you guys.
    I'll upload as soon as I can!

    Quote from wkchick

    ...some of your HEVC encoded videos (short excerpt both 10bit and 8bit) for us to test and make sure that it's not a hardware problem?

    1. Just to repeat this so there is no misunderstanding - my assumption that 10bit was the root cause was wrong. It's a global HEVC decoding issue (at least for my box) and applies to 8bit HEVC as well.

    2. A hardware problem is of course possible, which is why I will gladly accept your help to test samples! :)

    OK, I found a good example.
    The end credits from "Silicon Valley" - yellow text on black background.

    Download link:
    Uploadfiles.io - contour issue samples.7z

    Get close to the TV and look at the text edges, you can pause and look at a still frame too.


    The text edges are not clean on the x265 encodes, while they are perfectly clean on the x264 encode.
    The whole text should be pure yellow, as it is on the x264 encode, but the edges have a white-ish shimmer on the x265 encodes (left edge of letters).

    For me it looks like the x265 ones are right, Yellow text with highlight from the left. Are you certain that its not the x264 decoding that's just doing a bad job? :angel:

    Quote from 2re

    For me it looks like the x265 ones are right, Yellow text with highlight from the left. Are you certain that its not the x264 decoding that's just doing a bad job? :angel:

    Yes, I am certain. The highlight from the left is not supposed to be there. Every other player gets it right:
    - Kodi Windows
    - VLC Windows
    - TV's internal media player

    You can not tell AVC and HEVC apart on these players.

    Quote from jd17

    Yes, I am certain. The highlight from the left is not supposed to be there. Every other player gets it right:
    - Kodi Windows
    - VLC Windows
    - TV's internal media player

    You can not tell AVC and HEVC apart on these players.

    Just tested with Kodi on a Surface Pro 4 Windows 10, and Yes, your right. No highlights, just pure flat yellow text;)