Full Range Video Levels no longer working with MrMC.

[three6zerocool]

Hello.
When I first purchased MrMC, I calibrated the video output of my AppleTV4 using various video test patterns, including the popular free AVCHD709 patterns, which I keep a copy in MP4 container.

Anyway, as my TV supports full range video levels 0-255, I set AppleTV4 to RGB Low, and then used the patterns
and MRMC brightness and contrast settings under GUI video preferences.

All went very well, and I achieved virtually perfect brightness and contrast settings, with all white levels visible
from 0 thru 255.

In recent MrMC releases, the video levels are incorrect, and one can no longer even get white levels up to 235.
I had noticed that the video looked bit washed out, and had assumed my contrast settings in MrMC had reset to default or something. However, it seems to be either something that recent Apple TVOS update has altered, or it
is your software?.

I only mention it, as I can 100% confirm that MrMC has achieved full range video levels in the past, but seems to have lost that ability currently. It was one reason this app super impressed me, as the adjusted video output from
MrMC was brilliantly fantastic.

Anyone else noticed this?

I will need to try out a few other apps on ATV4, and see if the video levels are the same across all apps on ATV4, or if the effect is unique to MrMC only.

[cosmoxl]

Hello.
When I first purchased MrMC, I calibrated the video output of my AppleTV4 using various video test patterns, including the popular free AVCHD709 patterns, which I keep a copy in MP4 container.

Anyway, as my TV supports full range video levels 0-255, I set AppleTV4 to RGB Low, and then used the patterns
and MRMC brightness and contrast settings under GUI video preferences.

All went very well, and I achieved virtually perfect brightness and contrast settings, with all white levels visible
from 0 thru 255.

In recent MrMC releases, the video levels are incorrect, and one can no longer even get white levels up to 235.
I had noticed that the video looked bit washed out, and had assumed my contrast settings in MrMC had reset to default or something. However, it seems to be either something that recent Apple TVOS update has altered, or it
is your software?.

I only mention it, as I can 100% confirm that MrMC has achieved full range video levels in the past, but seems to have lost that ability currently. It was one reason this app super impressed me, as the adjusted video output from
MrMC was brilliantly fantastic.

Anyone else noticed this?

I will need to try out a few other apps on ATV4, and see if the video levels are the same across all apps on ATV4, or if the effect is unique to MrMC only.

Maybe tvOS 10 changed things?

[davilla]

We changed nothing regarding video levels. VideoToolBox is also set to output full range.

[Batman1310]

Video should be set to limited for TV and film watching, the range is 16-235. 16 being black and 235 being white. Anything above or below these settings should not really be seen. 0-255 is used with pc's.

[three6zerocool]

Yes, it could be the TVOS 10 update I guess.

I just thought it interesting, as I had previously calibrated the video levels on two AppleTV 4's connected to displays that support wide color gamut, and full range video, and really liked the results, and MrMC was unique to other players like my PC, Raspberry PI etc, as MrMC was the only one
that allowed brightness and contrast adjustment that actually worked.

[three6zerocool]

>Video should be set to limited for TV and film watching, the range is 16-235. 16 being black and 235 being white. >Anything above or below these settings should not really be seen. 0-255 is used with pc's.

Yes, that is true of the original analog based video standards, where black level in particular was higher in NTSC
derived formats due to frailties in that standard.

Many modern TV's are really more computer monitors with tuner capability.
They support wider color gamut, and are full video range capable.
ie. HD709, where brightness(greyscale) levels begin at digital 0 (black) and end at 255 (white)

The AppleTV4 supports (or did support) both RGB output ranges, depending what the end users display supports.
As you pointed out, for a more classic display that only supports 16-235, then one would choose RGB High in AppleTV video settings.

However, a lot of new digital content is created under HD709 digital video standard, which fully supports the wider
video levels, so if the display supports it, why not use it, and enjoy a better reproduction of the image from modern
mastered material.

As you correctly point out, the 16-235 range is safe, but many TV's now can easily represent full range levels.
My comments were more from the point of view of 'what has happened to them'

As the MrMC developers have now chimed in and commented they they have changed nothing, the obvious
suspect would now be Apple themselves.

I just wondered if anyone else noticed.

[three6zerocool]

Hello people.

Just an update regarding full range video issue I had noticed.
I got it working again.

The TVOS 10 update breaks RGB low mode on the AppleTV4.
The only fix appears to be to perform a full reset and restore on the affected AppleTV4's.
(of which I have a few, so that's kinda annoying)

Weird thing is that all my AppleTV's have been going fine, but unplugging them, rebooting.. Nothing fixes the full
range video levels. Only a full restore/update.

Anyway, thanks for the comments, and the input from the developers.

I am happy once more with blacker than black, and whiter than white video... No more crushed blacks.
The difference is more than noticeable.

Cheers..

[three6zerocool]

Another update regarding full range video.

Davilla, although VideoToolbox may be set to full range video, it would appear that it is currently outputting 16-235
only.

I enabled VTB in acceleration preference settings of MrMC, and it loses full range video level capability.
If I disable VTB, full range video levels are available once more.

I probably did not have to restore my appletv4 afterall. Oh well, how sad, too bad.

I like hardware acceleration, and I like full range video levels, but I can not currently have both.
(The lesser of two evils ). (grin)

[cosmoxl]

the other day just for kicks I enabled rgb low and went into my home theater test app. black and white levels were too dark and too bright for my tv. so I guess it doesn't support the extended range?

[three6zerocool]

Calibrate your display using AVCHD709 display patterns.

If you perform search, is some free ones as named above. You can download a disk image, or some MP4 files.
(Grab the MP4 files, and there is a folder called 'Basic' which contains patterns for black levels and white levels)

Set your AppleTV4 to RGB Low, and then use MrMC to play the patterns.

Adjust your TV settings first. Default the brightness and contrast settings on your TV.
Do brightness first to set so that bars 17 and above flash.
Do the white level test next, and reduce the contrast control until you see the max amount of bars.
You may have to go back and adjust brightness again.

When close, use the brightness and contrast settings in MrMC to fine tune, and save settings as default.

Note: disable VTB in Mr MC. else above does not currently work.
Of course, if your display does not support full range, then you will not see whites above 234.

The important adjustment tho, is contrast, so lower that and see if you see additional white levels.
In my case, I see all white levels right up to 254, with 255 being bright white.
If I enable VTB, I only see up to 234.