[BUG] S905X Krypton: Bad chroma upsampling

    Quote from kszaq


    I still don't have a new TV. :P

    Oh I didn't know that you don't have one at the moment? :(

    Quote


    For the next Krypton build I created a workaround that bypasses deinterlacer for all progressive videos except VC-1.

    That sounds great, so you made the best out of a difficult situation! :)

    I noticed another thing when trying out the Spears and Munsil pattern. There's quite severe banding in the red and blue gradients. This is not the case if you switch to software decoding, where the ramps are perfectly smooth. Also there is no overscan issue with software decoding. I can make a screen cap on the weekend.

    jd17: Maybe switching to RGB output reduces the number of colorspace conversons and gets rid of these artifacts. Have you tried it?

    It might just be my TV but what I see is this. I got the best result with my lg TV at pc mode.

    Bad chroma up sampling and color banding:
    1080p 24hz + 50hz (4:4:4 and RGB)

    All ok:
    1080p 60hz
    2160p 24hz + 50hz + 60hz (4:2:0 and 4:4:4)

    Quote from kubrickdave


    I noticed another thing when trying out the Spears and Munsil pattern. There's quite severe banding in the red and blue gradients. This is not the case if you switch to software decoding, where the ramps are perfectly smooth. Also there is no overscan issue with software decoding. I can make a screen cap on the weekend.

    jd17: Maybe switching to RGB output reduces the number of colorspace conversons and gets rid of these artifacts. Have you tried it?

    I have to correct myself. The banding issue is caused by my TV. I tried different sources as well as the integrated player. All show the same pattern. Software decoding clips whiter-than-white luminance levels, which might explain the smoother red and blue gradients. I think the lesson is, that there's high variance in equipment and it's hard to make general observations.

    Also I switched the output resolution to 2160p (previously on 1080p) and this got rid of the overscan.

    I tested libreelec 7 latest (k) Libreelec 8.0.1. (i) version and android minix u1 rom on mini mx
    Still bad both libreelec pic quality.
    Here is the 3 photo taken from tv:
    Libreelec 8:

    Libreelec 7:

    Minix Android MiniXbmc

    Look the blue horizontal track