EDID Override - Injecting a Dolby VSVDB Block

Thanks for the great work, I have been waiting for something like this for ages. I see many mentions of the Ugoos in this thread. Should this work in any Dolby vision capable amlogic-ng device like the Box R 4K Plus?

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If DV is working with that box on standard CE-21 ng Nightly, then no reason this would not work also - I think the only diff would be no p7 FEL.

If trying the recommendation is a new install on a separate sdcard.

Just be aware I only have a Ugoos so all my testing is on that, so no guarantees. :slight_smile:

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Hmm… VS10 didn’t trigger for me, files keep playing in HDR instead of DV…
Mode: On Demand
Type: Display Led (DV-Std)
Colorimetry: disable/remove
HDR10 => DV
HDR10+ => DV
Everything else => off

Was it a fresh install, if not maybe try switching between the settings, play and then switch back etc., not seeing that issue my side.

Edit: Looks like an On vs On Demand issue
Will look into it more, for now can use On or revert back to previous versions

Edit 2: Ok found it - it’s a defect - correcting will post another version later.

Me too but only via update folder. So how do we do a fresh install? Thanks

Feature Complete - Update 6

  • Fix defect with VS10 → DV not working in DV Type: On demand.

When testing use the below tar to update a fresh install of CE-21 ng.

Update tar

Dolby VSVDB Calc (no update)


Fresh install is getting the Nightly install and then using the tar to update that.
Issue though was a defect - should be fixed, please download [Feature Complete - Update 6]

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Fixed with a new version - lets see what else I broke :rofl:

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Everything looks good :+1:
Awesome work! Thanks again!!

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Hi still hdr on lg c6 any ideas why?

Thank you, I am testing on my projector (no native DV so I am using LLDV) to validate and experiment with the settings but wanted to see how you as the developer preferred the settings. Specifically:

Mode: ? Why do you prefer “On” vs “On Demand”?
SDR8 to X - Is there a difference if you choose SDR (assuming for SDR10)? I am not noticing any difference but DV sometimes over blows image.
HDRHLG to ? I rarely have HDRHLG material so was wondering what do you see when it is set to “DV” that you prefer it “off”

Thanks again.

Hi, sorry but with update six everything goes in HDR, even if I select DV on demand with LED DV st.
DV movies are all in HDR
Before everything worked
I also noticed that if you activate DV, the next time you switch to an HDR movie it messes up with the colors and resolution.

Ps. I installed the Omega_devel_20240609154632 version and everything works correctly. I have a standard DV and HDR10 projector.


Same here. It looks the same to me.

Hello, after few test, it is clear the maxlum value is not taken by the engine for DV->SDR conversion. So does it take maxlum from VSVDB even if it would be counter intuitive ?

Just checking you looked at the dmesg and see it sending the values you expect?

No real idea what is it doing as closed source, but sounds like it takes the mode “SDR” and internally just limits ignoring the passed in min and max, guess not taking the VSVDB either as that would be higher than 100, guessing around 300 for a projector?

Could also try forcing back to graphics mode.

This is the main call into the dovi.ko (as I understand) and best estimation of what is feeding in:

int control_path
	enum signal_format_enum in_format,					// SDR, HDR10, DV
	enum signal_format_enum out_format,					// SDR, HDR10, DV
	char *in_comp, int in_comp_size,					// Metadata ?	
    char *in_md, int in_md_size,						// Metadata ?	
	enum priority_mode_enum set_priority,				// Video or Graphics
	int set_bit_depth, 									// DV 12, DV no EL then 10, HDR10 10, SDR 10
	int set_chroma_format, 								// 0 !? maybe sub sampling and 422?
	int set_yuv_range,									// SMPTE

	int set_graphic_min_lum, int set_graphic_max_lum,	// grpahic min and max luminance (does change the OSD) Graphics priority I recall this may effect video as well.
	int set_target_min_lum, int set_target_max_lum,		// video min and max luminance (appears so far no effect).
	int set_no_el,										// Is there an enhancement layer.
	struct hdr10_parameter *hdr10_param,				// HDR10 display mastering and etc, from display.
	struct dovi_setting_s *output						// Core and luts setup, VSVDB - lots of info including repeat of some other info from above like in and out format.

Will need more details, post photos of the version (to confirm) and your DV config as a starting point.

Not really the “developer” of the conversion process, just enabling/configuring/exposing options that are already in the amlogic linux implementation.

Faster switching for me and lower luminance in Kodi menus with fine control (I prefer darker kodi/menus).

Don’t know if diff between off and SDR - it is certainly engaging the DV Engine with SDR and previously others have seen a difference - needs capture analysis to tell - not something I can do.

As I said in the release notes, it is processing in the DV Engine as “SDR” this SoC/dovi.ko cannot handle processing as “HDR HLG” and throws errors if forced. For me the colours are off - overall more muted than native “HDR HLG” on my TV.

Ok, thank you

Yes I’ve seen values passing through, but not any visible sudden change in DV video playing on the fly.
In my case my VSVDB was around 280nits maxlum, but I can’t visually confirm right away that it was taking 100 or 280.

I’ll try that:

  • Modifying VSVDB to spot any difference, In this case I need to be in DV “on demand” and play/stop between changes right ? I need to change values and also I’ll try changing color primaries values to see if it has any impact.

Question : Do you know if bt709 is the only color space output possible with this DV->SDR conversion ?

Before digging in the so called “graphic mode”, let me try to be sure VSVDB is not - mistakenly - involved

Yes, the VSVDB is changed before playback starts - applied only once each time.