Contrast adjustment not active on resume


#1

Just noticed something a little odd with current version of OSMC on a Vero4K+.

I run 1080 systems and with 4K mkv files, I need to punch up the contrast as the HDR->SDR conversion is far too muted for my display. Recently, the functionality to adjust contrast within Kodi was enabled, and as this is remembered on a file-specific basis it’s a good solution for me. However, suppose I set the contrast to 60% and stop playback. On resuming playback, the visible contrast has reverted to standard, but if I pull up the Kodi video adjustment menu, the contrast value in the menu is 60% - the moment I then adjust it, the visible contrast adjustment kicks in. So it looks like the stored values of the contrast adjustment are not being used on resume, but they work when adjusted in-stream. I have tried this with several files and behaviour is consistent.

If necessary I can post a log but hoping the problem description is clear enough.


#2

How are you resuming playback? A stop and play again, or are you pausing?


#3

Stop, then I press play and select resume.


#4

That’s expected.

Otherwise you should choose ‘Set as Default for All Videos’.


#5

I find that very odd. When I pull up the the video adjustment menu on resume, the adjusted contrast % is showing, but only for titles where I have adjusted it - which makes sense - except that it is not active - which does not make sense. Surely if the adjusted % is stored for the file, it should be referenced on starting playback?


#6

There’s a bug in the brightness/contrast code. Should be simple to fix.


#7

That just sounds like those sysfs params aren’t poked by VideoPlayer init; just on change in video settings. Should be an easy fix


#9

Thanks for the follow up, look forward to the fix.

To what extent are there plans or scope for looking at the SDR conversion? Default contrast is always far too low, my Panny UHD player does it pretty well. I need to set Kodi contrast to about 55% to match it, which delivers a considerable lift to highlights. Will this be better with v18 ?


#10

Plans - yes! Scope - not sure yet. Hoping there is just some wrong assumption been made in the kernel drivers which just needs correcting.


#11

Temporary workaround: it seems if you start a vid, stop it, then restart it it does observe the brightness and contrast settings you set in the last session.


#12

Not in my case. Whether I initiate playback from the start of the file or from a resume point, the stored contrast settings are definitely not being applied - they only activate if I adjust during playback, then the contrast visibly jumps to the level I had last time.


#13

I think just setting these values in AMLCodec open will do the trick
I can add it this if you’re willing to test.


#14

Very happy to test, thanks.