- This topic has 3 replies, 2 voices, and was last updated 5 years, 5 months ago by
.
-
Posts
-
Hi,
I am trying to make a 3D LUT for HDR to SDR in madVR using the 3D LUT Maker and the Synthetic ICC. The LUT imput bitdepth must be 8 bit because I need to use it with ffdshow which only outputs 8 bit. The problem is that I can’t load a HDR to SDR LUT as a calibration LUT in madVR, and the 3D LUT Maker doesn’t allow to make a madVR calibration LUT when you select SMPTE 2084. So I tried to make the LUT with the eecolor format (don’t even know if this could work) but madVR says that it’s not a valid 3DLUT file. Then I made a LUT with the eecolor format with default settings and madVR didn’t load it. Then I found a eecolor 65x65x65 3DLUT and madVR loaded it without any problem. Looking at the eecolor LUTs created with the 3D LUT Maker they don’t seem to be 65x65x65 because they have 1802240 entries.
Is this a problem with the 3D LUT Maker or maybe the eecolor format has changed?
Hi,
The LUT imput bitdepth must be 8 bit because I need to use it with ffdshow which only outputs 8 bit
This assumption is incorrect. The 3D LUT bitdepth has nothing to do with the video decoding bitdepth, or the video renderer output bitdepth.
Looking at the eecolor LUTs created with the 3D LUT Maker they don’t seem to be 65x65x65 because they have 1802240 entries.
eeColor LUTs created by calibration software are effectively 64 ^ 3 (262144 entries) despite the UI saying 65 ^ 3, because that is what the eeColor actually supports internally (point 65 is fixed). I don’t know where you got the 1802240 number.
EDIT: Needless to say, you shouldn’t create a eeColor 3D LUT for madVR. The only reason madVR even supports eeColor is because other calibration software wouldn’t write native madVR 3D LUTs, a limitation that does not apply to DisplayCAL. madVR converts all eeColor 3D LUTs to madVR format internally anyway.
This assumption is incorrect.
I didn’t know that, but what I meant is that madVR don’t aply a HDR to SDR LUT when it gets 8 bit input, so I wanted to load a normal calibration LUT in the calibration tab, but i guess this is not possible. Of course you’re right with the number, I count 1572864 values in groups of 6 = 262144 entries.
Thanks anyway.
I didn’t know that, but what I meant is that madVR don’t aply a HDR to SDR LUT when it gets 8 bit input
Video bitdepth is irrelevant, what matters is that HDR metadata is embedded in the video, otherwise it’s not HDR (although quantization artifacts would be an issue for HDR encoded at 8 bit, so that’s not likely something you’ll find. If the video is 8 bit, it’s likely SDR).
