2160p HDR to 1080p HDR - Printable Version +- Selur's Little Message Board (https://forum.selur.net) +-- Forum: Hybrid - Support (https://forum.selur.net/forum-1.html) +--- Forum: Problems & Questions (https://forum.selur.net/forum-3.html) +--- Thread: 2160p HDR to 1080p HDR (/thread-4217.html)

2160p HDR to 1080p HDR - Erikk64 - 20.09.2025 hi  again i recently did an encoding from 2160p to 1080p hdr ,and the result was a slightly different color.. did i miss something or should i expect results from dimension reduction also , i did the following: enable hdr + cll and fall from input + resize method 9-lanczos and i missed those : enable hdr opt enable master display .. the source MediaInfo  Color range                              : Limited Color primaries                          : BT.2020 Transfer characteristics                : PQ Matrix coefficients                      : BT.2020 non-constant Mastering display color primaries        : Display P3 Mastering display luminance              : min: 0.0050 cd/m2, max: 4000 cd/m2 Maximum Content Light Level              : 10000 cd/m2 Maximum Frame-Average Light Level        : 596 cd/m2 Original source medium                  : Blu-ray the result: Bit rate                                : 18.0 Mb/s Width                                    : 1 920 pixels Height                                  : 1 080 pixels Display aspect ratio                    : 16:9 Frame rate mode                          : Constant Frame rate                              : 23.976 (24000/1001) FPS Color space                              : YUV Chroma subsampling                      : 4:2:0 Bit depth                                : 10 bits Bits/(Pixel*Frame)                      : 0.362 Color range                              : Limited Color primaries                          : BT.2020 Transfer characteristics                : PQ Matrix coefficients                      : BT.2020 non-constant Maximum Content Light Level              : 10000 cd/m2 Maximum Frame-Average Light Level        : 596 cd/m2 RE: 2160p HDR to 1080p HDR - Selur - 20.09.2025 Yes, changing the resolution will (expectedly) at least somehow change the color perception. Note that your way of comparing the colors might be flawed. Depending on the player and the used video renderer, opening multiple instances might produce different color handling. You might want to check whether the displayed colors change, if you open the files in a different order. Personally, I would a. open the files in a Vapoursynth script (without the HDR data) for comparison. (assuming the hdr metadata are the same, one can ignore them for comparing) b. not use Lanczos, but SSIM, DPID, ResampleHQ or Spline64 for down scaling. (not sure whether they all work fine on HDR content) Not knowing what you really did in Hybrid, I doubt this is a bug. Cu Selur RE: 2160p HDR to 1080p HDR - Erikk64 - 20.09.2025 (not use Lanczos, but SSIM, DPID, ResampleHQ or Spline64 for down scaling.) i also tried this ,but the result was the same RE: 2160p HDR to 1080p HDR - Selur - 20.09.2025 No clue whether the HDR2SDR routine you use does anything different when confronted with HDR on HD content. Does the Vapoursynth Preview also show the color change? Cu Selur RE: 2160p HDR to 1080p HDR - Selur - 20.09.2025 Do these files show different colors for you? (I uploaded a UHD HDR test file and re-encoded it to a HD HDR test file.) => https://www.mediafire.com/folder/j415iw3euq43k/HDR+Test (they show no real color difference for me on my HDR display) Cu Selur RE: 2160p HDR to 1080p HDR - Erikk64 - 20.09.2025 no I don't remember exactly Because I did a lot of things and made many attempts Then I deleted the files to save space But I started asking because I got frustrated and expected that I made a mistake in something I haven't noticed yet RE: 2160p HDR to 1080p HDR - Selur - 20.09.2025 Since you didn't read the sticky, I have no clue what you did. You can use the Vapoursynth Preview to see whether the resizing does change the colors (without the HDR data). On reencoding, you should make sure that the signaling is set properly. Can't reproduce the problem, so my guess is that you made some mistake in whatever you did. Cu Selur RE: 2160p HDR to 1080p HDR - Erikk64 - 20.09.2025 Yeah, haha, I really thought about giving up on the idea completely, but my mind is still insisting. I'll give this matter more time later with some digging. RE: 2160p HDR to 1080p HDR - Selur - 20.09.2025 Do that, also use the latest dev, this way you are sure you used the same version I used for my test. Cu Selur