mpv not respecting Windows 11 HDR settings?

[meidoqt]

I noticed that mpv doesn't respect the "SDR content brightness" when playing SDR videos on Windows 11, unless I have target-colorspace-hint-mode=source set. Is this expected behaviour?

I'm using my display with HDR turned on and also with HDR calibration tool applied.

This also makes me question if mpv is respecting that calibration at all.

[kasper93]

I noticed that mpv doesn't respect the "SDR content brightness" when playing SDR videos on Windows 11, unless I have target-colorspace-hint-mode=source set. Is this expected behaviour?

Yes. If target-colorspace-hint-mode=source is set, SDR video is sent to compositor and this is converted to HDR (PQ) by Windows itself. Using this SDR content brightness slider in settings.

By default =target mode, the conversion to HDR is done by mpv. You can control brightness of SDR with --target-peak and --inverse-tone-mapping.

This also makes me question if mpv is respecting that calibration at all.

Yes. Calibration is used. It sets min luminance (black point) and max luminance. You can see those values in stats (shift+i)

[meidoqt]

Okay, it feels like these are the settings I want then:

target-colorspace-hint = auto
target-colorspace-hint-mode = source

Do these statistics look correct? 1st one is an HDR file, 2nd is SDR.

HDR file:

SDR file:

The other thing is, when I use target-trc=pq, target-prim=bt.2020, mpv will start tone-mapping the SDR file. My understanding is Windows 11 can display SDR files correctly when using HDR mode, so I don't see a need for mpv to start tone-mapping my SDR files, I guess.

[kasper93]

Do these statistics look correct? 1st one is an HDR file, 2nd is SDR.

Yes, they look correct for those settings. Although, for HDR I would recommend =target to perform tone mapping to target in mpv itself, not leave it outside, which is generally lower quality. Even Microsoft recommend tone-mapping to your display capabilities, which is what mpv is doing. Of course this depends on lots of factors, so adjust it how you prefer.

Also in =source mode, the calibration you asked before, is not used by mpv ifself, because it just sends to hdr video as is. If you want to use the calibration in mpv, this is what =target is doing.

The other thing is, when I use target-trc=pq, target-prim=bt.2020, mpv will start tone-mapping the SDR file. My understanding is Windows 11 can display SDR files correctly when using HDR mode, so I don't see a need for mpv to start tone-mapping my SDR files, I guess.

If you set target-trc=pq you are requesting mpv to convert SDR to PQ. Which is fine. And yes, Windows 11 can also do the same. Basically =target would do same as target-trc=pq, but also use display parameters.

[meidoqt]

Then I guess =target does sound like the better option. My last question is then can I use =target, but still have mpv respect the SDR brightness slider in Windows or is that not possible with =target?

[kasper93]

No, that would not be possible, but you can use autoprofile to set =source for SDR content, this way you delegate conversion to PQ to Windows which uses this slider as reference value.

Also the same control as "slider", like I mentioned before, is --target-peak and --inverse-tone-mapping in mpv, which you also can change only for SDR to adjust the brightness you get. For SDR there is no "perfect" value. It's up to you what brightness to get.