HDR to SDR : Bad color

[Atillart]

Hello, I have a recent film in both HDR and SDR formats.

I want to convert the HDR to SDR, aiming for a result similar to the SDR version.

I'm using Rigaya Nvenc to convert HDR to SDR.

I've tried all the available algorithms, and the result is always a greener image than the SDR version.

I don't know if there's a setting to slightly shift the colorimetry so that it leans more towards blue than green?

[videoAI]

try clever FFmpeg-GUI
Saturation can be manipulated, in edition to color space, color range, pixel format,
SDR->HDR, SDR-> HLG, and color lookup tables [LUTs].

[Selur]

What does your command line look atm. ?

I've tried all the available algorithms, and the result is always a greener image than the SDR version.

You did try adjusting the settings, especially when trying 'vpp-libplacebo-tonemapping'.

Also, no need to use ffmpeg separately, just to use a LUT (from example: https://github.com/FranceBB/LinearTransformation) '--vpp-libplacebo-tonemapping-lut ' allows this too.

[Atillart]

What does your command line look atm. ?

I've tried all the available algorithms, and the result is always a greener image than the SDR version.

You did try adjusting the settings, especially when trying 'vpp-libplacebo-tonemapping'.

Also, no need to use ffmpeg separately, just to use a LUT (from example: https://github.com/FranceBB/LinearTransformation) '--vpp-libplacebo-tonemapping-lut ' allows this too.

I don't use libplacebo-tonemapping (I don't know why, but it doesn't work on nvencc via stax), just hdr2sdr :

--vpp-colorspace matrix=bt2020nc:bt709,colorprim=bt2020:bt709,trans fer=smpte2084:bt709,range=limited:limited,hdr2sdr= mobius

[Selur]

The greenish tint might be because of using 'mobius', iirc. it can add a greenish tint some pc vs tv luma scale problem can also cause a green tint.
If it's mobius, chaning desat_strength to a lower value might help. for the luma scale try range=full:limited, not really accustomed to StaxRip, so no clue whether it might be a processing problem before the encoder,...