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Raised blacks
Posted: 30 Dec 2018, 15:36
by keithl
I really like MrMC as I can use it on my Shield and Apple TV 4K. Everything works fine on my Shield and I realize the versions and UI are different between platforms currently, but on both my ATV4K one on my OLED the other on my Sony X900E the blacks are raised on the ATV4K devices. I have verified that the RGB range settings support 16-256 and yet the black bars are not deep black but loom raised. Same content on my Shield or even using Infuse looks perfect, is this bug going to be fixed soon?
Re: Raised blacks
Posted: 30 Dec 2018, 15:49
by davilla
The only issue we know about on AppleTV4K is that blacks are slightly raised by one or two levels on HDR content only.
The reason tracks back to using OpenGLES. The fix is to move to Metal for rendering. This change is non-trivial and will take some time to happen. There is no ETA as yet.
Re: Raised blacks
Posted: 30 Dec 2018, 18:14
by keithl
I have this issue on SDR content which were all MakeMKV rips of 1080p Blu-rays. I have ATV4K set to SDR and match range and refresh. I can run the same MKV through MrMC on my Shield and my Oppo 203 and black bars are perfect. I have uninstalled and reinstalled on both of my ATV4Ks and made sure the RGB setting is for 16-256. I will try and get a picture on my OLED since it is in a pitch black room.
Re: Raised blacks
Posted: 30 Dec 2018, 18:48
by keithl
here are 2 shots of same scene on same TV. Botht he Shield and ATV4K connect through my Denon with no video processing.
Notice the top black bar ont he ATV4K image is not black and the overall PQ seems more washed out and elevated brightness overall. If I play same video through Infuse or my Shield (seodn pic) or Oppo all connected exact same way they all look identical. Something with MrMC on the ATV4K.
If I take the 4K UHD Rip of 2001 it is very pronounced since there are so many black scenes. And in that case I can then also compare to iTunes 4K copy and again all but MrMC version the blacks, colors and contrast are identical.
This is on a calibrated LG 65C7 OLED in a dark room. I can runt he same test on a Sony X900E in a more lit room and still see the difference as well and on the Sony the ATV4K is direct connected.
It is easier to go to the URL and click Original size and it us more obvious.
ATV4K Notice the overall raised brightness and the black bar is not black
http://www.pbase.com/kluken/image/168610041
Shield image, everything looks perfect.
http://www.pbase.com/kluken/image/168610042
Re: Raised blacks
Posted: 30 Dec 2018, 19:12
by davilla
If you set MrMC to use AVFoundation for all hw decoding, you will see blacks raised. For the above reason.
HW VideoToolBox should be fine BUT it will not handle HDR/Dolby Vision correctly.
How is yours setup ? (settings/video/acceleration)
Re: Raised blacks
Posted: 30 Dec 2018, 19:30
by keithl
AVFoundarion was enabled, but when I disabled it there was no difference and now HDR blacks are raised. I tried all combinations of decoding settings and if HW decoding was disabled UHD content shuddered and was flat.
Re: Raised blacks
Posted: 31 Dec 2018, 00:27
by davilla
Please test with actual test pattern videos. Videos are too subjective.
We and some users have done extensive testing regarding levels.
Re: Raised blacks
Posted: 31 Dec 2018, 00:43
by keithl
I will try and locate test patterns, but I have tried dozens of SDR rips and all have raised black bars and look fine with Infuse, my Shield using MrMC and my Oppo all using same MKV files from my NAS.
Re: Raised blacks
Posted: 08 Jan 2019, 01:12
by keithl
I have not had any luck finding SDR test patterns. I have trie everything I can, it always evelates brightness.
Re: Raised blacks
Posted: 10 Feb 2019, 21:19
by avrelkb
Hello, i am a long time mrmc user. I wanted to report the same behaviour on on my setup.
Apple tv 4k, TV OLED LGC8.
Some part that should be black (black bars, background of ending credit,...) are not black but a bit above. The problem was not really noticeable on my previous tv, but since switching to an OLED it becomes clear.
I triple checked the the black level (limited / low) settings, and the same file played with VLC on the same apple tv plays correctly.